Development of Human Pituitary Neuroendocrine Tumor Organoids to Facilitate Effective Targeted Treatments of Cushing’s Disease

Abstract

(1) Background: Cushing’s disease (CD) is a serious endocrine disorder caused by an adrenocorticotropic hormone (ACTH)-secreting pituitary neuroendocrine tumor (PitNET) that stimulates the adrenal glands to overproduce cortisol. Chronic exposure to excess cortisol has detrimental effects on health, including increased stroke rates, diabetes, obesity, cognitive impairment, anxiety, depression, and death. The first-line treatment for CD is pituitary surgery. Current surgical remission rates reported in only 56% of patients depending on several criteria. The lack of specificity, poor tolerability, and low efficacy of the subsequent second-line medical therapies make CD a medical therapeutic challenge. One major limitation that hinders the development of specific medical therapies is the lack of relevant human model systems that recapitulate the cellular composition of PitNET microenvironment.
(2) Methods: human pituitary tumor tissue was harvested during transsphenoidal surgery from CD patients to generate organoids (hPITOs).
(3) Results: hPITOs generated from corticotroph, lactotroph, gonadotroph, and somatotroph tumors exhibited morphological diversity among the organoid lines between individual patients and amongst subtypes. The similarity in cell lineages between the organoid line and the patient’s tumor was validated by comparing the neuropathology report to the expression pattern of PitNET specific markers, using spectral flow cytometry and exome sequencing. A high-throughput drug screen demonstrated patient-specific drug responses of hPITOs amongst each tumor subtype. Generation of induced pluripotent stem cells (iPSCs) from a CD patient carrying germline mutation CDH23 exhibited dysregulated cell lineage commitment.
(4) Conclusions: The human pituitary neuroendocrine tumor organoids represent a novel approach in how we model complex pathologies in CD patients, which will enable effective personalized medicine for these patients.

1. Introduction

Cushing’s disease (CD) is a serious endocrine disorder caused by an adrenocorticotropic hormone (ACTH)-secreting pituitary neuroendocrine tumor (PitNET) that stimulates the adrenal glands to overproduce cortisol [1,2,3,4]. The WHO renamed pituitary adenomas as PitNETs [5]. While PitNETs have been defined as benign, implying that these tumors cause a disease that is not life threatening or harmful to health, in fact chronic exposure to excess cortisol has wide-ranging and detrimental effects on health. Hypercortisolism causes increased stroke rates, diabetes, obesity, depression, anxiety, and a three-fold increase in the risk of death from cardiovascular disease and cancer [4,6,7,8].
The first-line treatment for CD is pituitary surgery, which is followed by disease recurrence in 50% of patients during the 10-year follow-up period after surgery in the hands of an experienced surgeon [9,10,11]. Studies have demonstrated that surgical failures and recurrences of CD are common, and despite multiple treatments, biochemical control is not achieved in approximately 30% of patients. This suggests that in routine clinical practice, initial and long-term disease remission is not achieved in a substantial number of CD patients [7,12]. Hence, medical therapy is often considered in the following situations: when surgery is contraindicated or fails to achieve remission, or when recurrence occurs after apparent surgical remission. While stereotactic radiosurgery treats incompletely resected or recurrent PitNETs, the main drawbacks include the longer time to remission (12–60 months) and the risk of hypopituitarism [3,13,14]. There is an inverse relationship between disease duration and reversibility of complications associated with the disease, thus emphasizing the importance of identifying an effective medical strategy to rapidly normalize cortisol production by targeting the pituitary adenoma [4,7,12]. Unfortunately, the lack of current standard of care treatments with low efficacy and tolerability makes CD a medical therapeutic challenge.
The overall goal of medical therapy for CD is to target the signaling mechanisms to lower cortisol levels in the body [15,16]. The drugs offered for treatment of CD vary in the mechanism of action, safety, tolerability, route of administration, and drug–drug interactions [15,16]. In the era of precision medicine [17], where it is imperative to identify effective therapies early, there is an urgent need to accelerate the identification of therapies targeted to the ACTH-secreting pituitary tumor which are tailored for each individual patient. The absence of preclinical models that replicate the complexity of the PitNET microenvironment has prevented us from acquiring the knowledge to advance clinical care by implementing therapies specifically targeting the tumor, which would have a higher efficacy and tolerability for CD patients. In this instance, organoids can replicate much of the complexity of an tumor. An “organoid” is defined as a three-dimensional cell structure, grown from primary cells of dissociated pituitary tumors in Matrigel matrix, which proliferate, and differentiate in three dimensions, eventually replicating key biological properties of the tissue [18]. While pituitary cell lines predominantly represent hormonal lineages, these cultures do not reproduce the primary pituitary tissue because of the tumor transformation and non-physiological 2D culture conditions [19,20,21]. Pituitary tissue-derived organoids have been generated from mouse models [22,23]. While several human and rat pituitary spheroid/aggregate/tumoroid models have been reported, these cultures consist of poorly differentiated cells with high replicative potential which can affect drug response and produce data that poorly translate to the clinic [24,25]. In this study, we developed an organoid model derived from human PitNETs that replicated much of the cellular complexity and function of the patient’s tumor. Organoids derived from corticotroph PitNETs retained the genetic alterations of the patient’s primary tissue.

2. Materials and Methods

2.1. Generation and Culture of Human Pituitary Neuroendocrine Tumor (PitNET) Organoids

Patients with planned transsphenoidal surgery for pituitary tumors were identified in the outpatient neurosurgery clinics. Tissues were collected under the St. Joseph’s Hospital and Barrow Neurological Institute Biobank collection protocol PHXA-05TS038 and collection of outcomes data protocol PHXA-0004-72-29, with the approval of the Institutional Review Board (IRB) and patient consent. Samples were de-identified and shipped to the Zavros laboratory (University of Arizona) for processing.
Pituitary tumor tissue was collected in Serum-Free Defined Medium (SFDM) supplemented with ROCK inhibitor (Y27632, 10 µM), L-glutamine (2 mM), A83-01 (activin receptor-like kinase (Alk) 4/5/7 inhibitor, 0.5 mM), penicillin/streptavidin (1%), kanamycin (1%), amphotericin/gentamycin (0.2%), CHIR-98014 (4 mM), and thiazovivin (TZV, 2.5 mM). Tissues that contained red blood cells were incubated with Red Blood Cell (RBC) Lysis Buffer according to the manufacturer’s protocol (Thermo Fisher Scientific, San Fransisco, CA, USA). Tissues were dissected into small pieces, transferred to digestion buffer (DMEM/F12 supplemented with 0.4% collagenase 2, 0.1% hyaluronic acid, 0.03% trypsin-EDTA) and incubated for 5–10 min at 37 °C with gentle shaking. Tissue was further incubated with Accutase™ (Thermo Fisher Scientific) for 5 min at 37 °C. Enzymatically dissociated cells were pelleted and washed in DPBS supplemented with antibiotics at a 400 relative centrifugal force (RCF) for 5 min. Dissociated adenoma cells were resuspended in Matrigel™, and Matrigel™ domes containing the cells were then plated in culture dishes and overlaid with pituitary growth media (Supplemental Table S1). The culture was maintained at 37 °C at a relative humidity of 95% and 5% CO2. Organoid growth medium was replenished every 3–4 days and passaged after 15 days in culture.

2.2. Generation of Induced Pluripotent Stem Cells (iPSCs)

Induced pluripotent stem cell lines (iPSC lines) were generated from control individuals (no reported disease) or CD patients according to published protocols by the University of Arizona iPSC Core [26]. All human iPSC lines were tested and found to be negative for mycoplasma contamination using the Mycoalert Mycoplasma testing kits (LT07-318, Lonza), and no karyotype abnormalities were found (KaryoStat+, Thermo).

2.3. Pituitary Organoids Generated from iPSCs

Six well culture plates were coated with 2 mL/well 0.67% Matrigel (diluted in E8 media, UA iPSC core, 151169-01) and incubated at 37 °C at a relative humidity of 95% and 5% CO2 overnight. The iPSC lines were reprogrammed from the blood of either a healthy donor (JCAZ001) or a CD patient (iPSC7 and iPSC1063) at the University of Arizona iPSC Core. Passage 12 iPSCs were plated onto the coated plates and incubated at 37 °C at a relative humidity of 95% and 5% CO2. At 70% confluency, cells were passaged to freshly coated 24 well plates at a ratio of 1:8 and grown to 85–90% confluency before beginning the directed differentiation schedule. From days 0 to 3, cells were cultured in E6 media supplemented with 1% penicillin/streptomycin, 10 μM SB431542, and 5 ng/mL BMP4. BMP4 was withdrawn from the culture at day 3. Starting on day 4, the cells were cultured in E6 media, supplemented with 10 μM SB431542, 30 ng/mL human recombinant SHH, 100 ng/mL FGF8b, 10 ng/mL FGF18, and 50 ng/mL FGF10. Fifteen days after culture, the cells were harvested in cold E6 media by pipetting and resuspended in Matrigel™ (20,000 cells/50 mL Matrigel™). Matrigel™ domes containing the cells were plated in culture dishes and overlaid with differentiation media containing E6 media which was supplemented with 10 μM Y-27632, 30 ng/mL human recombinant SHH, 100 ng/mL FGF8b, 10 ng/mL FGF18, and 50 ng/mL FGF10 (Supplemental Table S2). Organoids were cultured for a further 15 days at 37 °C at a relative humidity of 95% and 5% CO2.

2.4. Spectral Flow Cytometry (Cytek™ Aurora)

The multicolor flow cytometry panel was designed using the Cytek® Full Spectrum Viewer online tool to calculate the similarity index (Supplemental Figure S1). The organoids were harvested in cold SFDM media and centrifuged at 400× g for 5 min. Supernatant was discarded and organoids were dissociated to single cells using Accutase® (Thermo Fisher Scientific 00-4555-56). The enzymatic reaction was stopped using prewarmed DPBS, and cells were then centrifuged at 400× g for 5 min and incubated with fluorochrome-conjugated/unconjugated primary surface or cytoplasmic antibodies (Supplemental Figure S1) at 4 °C for 30 min. Cells were then washed with Cell Staining Buffer (BioLegend # 420-201) and incubated with secondary antibodies (Supplemental Figure S1) at 4 °C for 30 min. Cells were fixed using Cytofix/Cytoperm™ Fixation/Permeabilization Solution (BD Biosciences # 554714) at 4 °C for 20 min, followed by washing with Fixation/Permeabilization wash buffer. Cells were labeled with fluorochrome-conjugated/unconjugated intracellular primary antibodies (Supplemental Figure S1) at 4 °C for 30 min, then washed and incubated with secondary antibodies at 4 °C for 30 min. Cells were resuspended in cell staining buffer and fluorescence and measured using the Cytek Aurora 5 Laser Spectral Flow Cytometer. An unstained cell sample was fixed and used as a reference control. UltraComp eBeads™, Compensation Beads (Thermo Fisher Scientific # 01-2222-42) were stained with the individual antibodies and used as single stain controls for compensation and gating. Data were acquired using the Cytek™ Aurora and analyzed using Cytobank software (Beckman Coulter, Indianapolis, IN, USA).

2.5. Whole Mount Immunofluorescence

Organoids were immunostained using published protocols by our laboratory [27,28,29]. Proliferation was measured by using 5-ethynyl-2′-deoxyuridine (EdU) incorporation according to the Manufacturer’s protocol (Click-IT EdU Alexa Fluor 555 Imaging Kit, Thermo Fisher Scientific C10338). Co-staining was performed by blocking fixed organoids with 2% donkey serum (Jackson Immuno Research, # 017-000-121) diluted in 0.01% PBST for 1hr at room temperature. Organoids were then incubated overnight at 4 °C with primary antibodies, followed by secondary antibodies and Hoechst (Thermo Fisher Scientific H1399, 1:1000 in 0.01% PBST) for 1 h at room temperature. Human specific primary antibodies used included: rabbit anti-ACTH (Thermo Fisher Scientific 701293, 1:250), rabbit anti-Synaptophysin (Thermo Fisher Scientific PA5-27286, 1:100), species PIT1 (Thermo Fisher Scientific PA5-98650, 1:50), rabbit anti-LH (Thermo Fisher Scientific PA5-102674, 1:100), mouse anti-FSH (Thermo Fisher Scientific MIF2709, 1:100), mouse anti-PRL (Thermo Fisher Scientific CF500720, 1:100), Alexa Flour conjugated GH (NB500-364AF647, 1:100), and mouse anti-CAM5.2 (SIGMA 452M-95, 1:250). The secondary antibodies used included Alexa Fluor 488 Donkey Anti Rabbit IgG (H+L) (Thermo Fisher Scientific A21206, 1:100) or Alexa Fluor 647 Donkey Anti Mouse IgG (H+L) (Thermo Fisher Scientific A31571, 1:100). Organoids were visualized and images were acquired by confocal microscopy using the Nikon CrestV2 Spinning Disk (Nikon, Melville, NY, USA). Fluorescence intensity and percentage of EdU positive cells of total cells, were calculated using Nikon Elements Software (Version 5.21.05, Nikon, Melville, NY, USA).

2.6. Nuclear Morphometric Analysis (NMA)

Nuclear Morphometric Analysis (NMA) using treated organoids was performed based on a published protocol that measures cell viability based on the changes in nuclear morphology of the cells, using nuclear stain Hoechst or DAPI [30]. Images of organoid nuclei were analyzed using the ImageJ Nuclear Irregularity Index (NII) plugin for key parameters, which included cell area, radius ratio, area box, aspect, and roundness. Using the published spreadsheet template [30], the NII of each cell was calculated with the following formula: NII = Aspect − Area Box + Radius Ratio + Roundness. The area vs. NII of vehicle-treated cells were plotted as a scatter plot using the template, and was considered as the normal cell nuclei. The same plots were generated for each condition, and the NII and area of treated cells were compared to the normal nuclei, and classified as one of the following NMA populations: Normal (N; similar area and NII), Mitotic (S; similar area, slightly higher NII), Irregular (I; similar area, high NII), Small Regular (SR; apoptotic, low area and NII), Senescent (LR; high area, low NII), Small Irregular (SI; low area, high NII), or Large Irregular (LI; high area, high NII). Cells classified as SR exhibited early stages of apoptosis, and cells classified as either I, SI, or LI exhibited significant nuclear damage. The percentage of cells in each NII classification category were calculated and plotted as a histogram using GraphPad Prism.

2.7. ELISA

Concentration of secreted ACTH in conditioned media that was collected from organoid cultures was measured using the Human ACTH ELISA Kit (Novus Biologicals, NBP2-66401), according to the manufacturer’s protocol. The enzyme–substrate reaction was measured spectrophotometrically (BioTek Gen5 Micro Plate Reader Version 3.11, Santa Clara, CA, USA) at a wavelength of 450 nm, and the ACTH concentration (pg/mL) was interpolated by a standard curve with a 4-parameter logistic regression analysis, using GraphPad Prism (Version 9.2.0, San Diego, CA, USA).

2.8. Drug Assay

Patient adenoma-derived pituitary organoids were grown in 96-well plates and treated with 147 small molecules taken from the NCI AOD9 compound library for 72 h. (https://dtp.cancer.gov/organization/dscb/obtaining/available_plates.html (accessed on 22 August 2021)). Drugs were diluted from 10 mM DMSO stock plates into 100 M DMSO working stocks with a final concentration of 1μM. All vehicle controls were treated with 0.1% DMSO. Organoid proliferation was measured using a CellTiter 96® AQueous One Solution Cell Proliferation Assay kit (MTS, Promega, G3582, Madison, WI, USA) according to the manufacturer’s instruction. Organoid death was calculated based on the absorbance readings at 490 nm, collected from the MTS assay relative to the vehicle controls. Drug screens were performed with biological replicates in the same screen. Drugs were selected based on their ability to target key signaling pathways as well as clinical relevance to the treatment. Drug sensitivity is represented by cell viability, and is significant at <0.5 suppressive effect of the drugs. The percent of cell viability relative to the vehicle control was calculated. Correlation coefficients across each organoid were calculated using the Pearson method to assess confidence in replication. The variance component was detected for each drug across all organoids. A random effect model was run with a single random factor for each drug, and estimated variance was calculated by rejecting the null hypothesis that variation was not present among samples. The drug responses were grouped by variance factor, into large (vc > 100), median (100 > vc > 50), and small (vc < 50). A heatmap was used to display the differential responses in cell viability for the drugs.
Drugs that clustered together and showed response within corticotrophs were investigated further based on their mode of action. Pathways (Kegg and Reactome) and gene ontology mapping were conducted for the genes that were being targeted by the drugs, in order to evaluate the key responses in cellular processes. A network was constructed in Cytoscape v 3.8.2 (San Diego, CA, USA) for the purpose of association between the drugs and genes.

2.9. Drug Dose Responses

Organoids were grown in Matrigel™ domes within 96-well round-bottom culture plates. Recombinant human SHH was removed from the pituitary organoid growth media, 24 h prior to drug treatment. Organoids were treated with either vehicle (DMSO), cabergoline (Selleckchem S5842), ketoconazole (Selleckchem S1353), roscovitine (Selleckchem S1153), GANT61 (Stemcell Technologies 73692), pasireotide (TargetMol TP2207), mifeprostone (Selleckchem S2606), etomidate (Selleckchem S1329), mitotane (Selleckchem S1732), metyropane (Selleckchem S5416), or osilodrostat (Selleckchem S7456) at concentrations of 0, 1, 10, 100, 1000, and 10,000 nM, for 72 h. The percentage of cell viability was measured using an MTS assay (Promega G3580). Absorbance was measured at 490 nm and normalized to the vehicle. Concentrations were plotted in a logarithmic scale, and a nonlinear dose response curve regression was calculated using GraphPad Prism. An IC50 value for each drug treatment was determined based on the dose response curve, using GraphPad Prism analysis software.

2.10. Calculation of Area under the Curve (AUC)

AUC (area under the curve) was determined by plotting the normalized % cell viability versus transformed concentration of the drugs, using a trapezoidal approximation for the area [31]. The formula was based on splitting the curve into trapezoids with bases equal to the % viability (V) and height equal to the interval length (difference in concentrations (C), and then summing the areas of each trapezoid:

n0(Vn+Vn1)2(CnCn1)

2.11. Quantitative RT PCR (qRT-PCR)

RNA was collected from patient-derived organoid cultures using the RNeasy Mini Kit (Qiagen). cDNA was generated from the extracted RNA, and then pre-amplified using TaqMan PreAmp Master Mix (Thermo Fisher Scientific 391128). The primers used were human-specific GAPDH (Thermo Fisher Scientific, Applied Biosystems Hs02786624_g1), NR5A1 (SF1) (Thermo Fisher Scientific, Hs00610436_m1), PIT1 (Thermo Fisher Scientific, Hs00230821_m1), TPit (Thermo Fisher Scientific, Hs00193027), and POMC (Thermo Fisher Scientific, Hs01596743_m1). Each PCR reaction was performed using a final volume of 20 µL, composed of 20X TaqMan Expression Assay primers, 2X TaqMan Universal Master Mix (Applied Biosystems, TaqMan® Gene Expression Systems), and a cDNA template. Amplification of each PCR reaction was conducted in a StepOne™ Real-Time PCR System (Applied Biosystems, Foster City, CA, USA), using the following PCR conditions: 2 min at 50 °C, 10 min at 95 °C, denaturing for 15 s at 95 °C, and annealing/extending for 1 min at 60 °C, for a total of 40 cycles. Relative fold change was calculated using the 2 − ∆∆Ct method [32], where CT = threshold cycle. Results were analyzed as the average fold change in gene expression compared to the control, and GAPDH served as an internal control.

2.12. Whole Exome Sequencing

WES was performed by the University of Arizona Center for Applied Genetics and Genomic Medicine. Isolated DNA from patient adenoma tissue will be quantified using the Qubit quantitation system with standard curve, as per the supplier protocol (Thermo Fisher Scientific). All samples were further tested for quality using the Fragment Analyzer (Advanced Analytical), following the manufacturer-recommended protocols. Whole exome sequencing (WES) was performed by array capture and approximately 60 Mb of exome target sequence, using the SureSelectXT Human All Exon V6 enrichment (Agilent) or equivalent (which one was used). All exome library builds were quantified via qPCR and subsequently sequenced to a minimum 20X coverage, using paired-end chemistry on the Illumina NovaSeq platform. Whole exome sequencing (WES) was performed by hybridization capture of approx. 35 Mb of the exome target sequence, using the Swift Exome Hyb Panel (Swift Biosciences 83216). All exome library builds were quantified via qPCR and subsequently sequenced to a minimum 20X coverage, using paired-end chemistry on the Illumina NextSeq500 or NovaSeq platform (Illumina). DNA reads were trimmed, filtered by quality scores and aligned to the human genome (hg38) with Burrows–Wheeler Aligner with default parameters. Picard (http://broadinstitute.github.io/picard (accessed on 22 December 2021)) was used to mark duplicates. Germline single nucleotide variants (SNV) were called using the Genome Analysis Tool Kit (GATK), using the given guidelines. Mutations were annotated using ANNOVAR for coding sequences. Variants that passed the quality filter were further investigated for similarity. Concordance between tissue and organoids was calculated using Jaccard similarity index (Jij = Mij/(Mi + Mj − Mij) where Mi is the number of variants in tissues, Mj is the number of variants in organoids, and Mij is the number of identical variants in both tissue and organoid.

2.13. Single Cell RNA Sequencing (scRNA-Seq)

Cultures were collected on day 15 of the pituitary directed differentiation schedule, and cells were dissociated into a single-cell suspension using Cell Dissociation Buffer (Thermo Fisher Scientific 13151014). Cells (15,000 cells/sample) were resuspended in the sample buffer (BD Biosciences 65000062), filtered using cell strainer (40 microns), and loaded into a BD Rhapsody cartridge (BD Biosciences 400000847) for single-cell transcriptome isolation. Based on the BD Rhapsody system whole-transcriptome analysis for single-cell whole-transcriptome analysis, microbead-captured single-cell transcriptomes were used to prepare a cDNA library. Briefly, double-stranded cDNA was first generated from the microbead-captured single-cell transcriptome in several steps, including reverse transcription, second-strand synthesis, end preparation, adapter ligation, and whole-transcriptome amplification (WTA). Then, the final cDNA library was generated from double-stranded full-length cDNA by random priming amplification using a BD Rhapsody cDNA Kit (BD Biosciences, 633773), as well as the BD Rhapsody Targeted mRNA and WTA Amplification Kit (BD Biosciences, 633801). The library was sequenced in PE150 mode (paired-end with 150-bp reads) on NovaSeq6000 System (Illumina). A total of 80,000 reads were demultiplexed, trimmed, mapped to the GRCh38 annotation, and quantified using the whole transcriptome analysis pipeline (BD Rhapsody™ WTA Analysis Pipeline v1.10 rev6, San Jose, CA, USA) on the Seven Bridges Genomics platform (https://igor.sbgenomics.com (accessed on 4 April 2022)), prior to clustering analysis in Seurat. For QC and filtration, read counting and unique molecular identifier (UMI) counting were the principal gene expression quantification schemes used in this single-cell RNA-sequencing (scRNA-seq) analysis. The low-quality cells, empty droplets, cell doublets, or multiplets were excluded based on unique feature count (less than 200 or larger than 2500), as they may often exhibit either an aberrantly high gene count or very few genes. Additionally, the mitochondrial QC metrics were calculated, and the cells with >5% mitochondrial counts were filtered out, as the percentage of counts originating from a set of low-quality or dying cells often exhibit extensive mitochondrial contamination. After the removal of unwanted cells from the single cell dataset, the global-scaling normalization method LogNormalize was employed. This method normalizes the feature expression measurements for each cell by the total expression, multiplies this by a scale factor (10,000), and log-transforms the result. The molecules per gene per cell, based on RSEC error correction (RSEC_MolsPerCell file) matrix files from iPSCctrl and iPSCCDH23 samples, were imported into Seurat v4, merged, and processed (as stated above) for UMAP reduction, cluster identification, and differential marker assessment using the FindAllMarkers function within Seurat.

2.14. Statistical Analyses

Sample size was based on assessment of power analysis using SigmaStat software. Data collected from each study from at least 4 in vitro technical replicates were analyzed by obtaining the mean ± standard error of the mean (SEM), unless otherwise stated. The significance of the results was then tested using commercially available software (GraphPad Prism, GraphPad software, San Diego, CA, USA).

3. Results

3.1. Generation and Validation of Human PitNET Tissue Derived Organoids

Human PitNET tissue was harvested during endoscopic transsphenoidal pituitary surgery from 35 patients in order to generate organoids. These cultures are referred to as human PitNET tissue derived organoids (hPITOs). Supplementary Table S3 summarizes the neuropathology reports and clinical diagnosis from these cases. In summary, 12 corticotroph (functional, CD), and 3 silent corticotroph tumors (nonfunctional tumors), 9 gonadotroph tumors, 8 lactotroph tumors, and 3 somatotroph tumors (acromegaly) were used to generate hPITOs (Supplementary Table S3).
Bright-field microscopy images of hPITOs that were generated from corticotroph adenomas from patients diagnosed with CD (Figure 1a–e). Silent/nonfunctioning tumors (Figure 1f,g) revealed morphological diversity among the organoid lines between individual patients and amongst subtypes. Confocal microscopy was used to capture a z-stack through the hPITO38, immunofluorescently stained for CAM5.2 (red), ACTH (green), and Hoechst (nuclear staining, blue) and emphasizes the 3D cellular structure of the hPITOs (Supplemental Video S1). Lactotroph, gonadotroph, and somatotroph adenomas were used to generate hPITOs, and showed the same morphological divergence amongst subtypes and between each patient line (Supplemental Figure S2). Proliferation was measured within the cultures using 5-ethynyl-2′-deoxyuridine (EdU) uptake and showed that the percentage of EdU+ve cells/total Hoechst+ve nuclei directly correlated with the pathology MIB-1 (Ki67) score (red, R2 = 0.9256) (Figure 1a–g, Supplemental Figure S2). ACTH concentration, which was measured by ELISA using organoid conditioned culture media collected from each hPITO line, showed the highest expression in the corticotroph adenoma organoids generated from CD patients (Figure 1h).
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Figure 1. Morphology and function of corticotroph hPITOs. (ag) Brightfield images, immunofluorescence staining using antibodies specific for CAM5.2 (red), ACTH (green), and EdU (magenta, inset) of organoid cultures generated from patients with Cushing’s disease (hPITOs 1, 7, 10, 33, 35) or nonfunctional corticotroph adenomas (hPITO8, 12). Quantification of %EdU positive cells/total cell number is shown and compared to the Ki67 score given in the pathology report (Supplemental Table S3). An ELISA was performed using conditioned media collected from (h) corticotroph hPITO cultures and (i) lactotroph, somatotroph, and gonadotroph hPITO cultures for the measurement of ACTH secretion (pg/mL).

3.2. Characterization of Cell Lineages in Pituitary Adenoma-Derived Organoids by Spectral Cytek™ Aurora Analysis

In order to validate the similarity in cell lineages identified between the organoid line and the patient’s tumor, we compared the immunohistochemistry from the neuropathology report (Supplemental Table S3) to the expression pattern of pituitary adenoma-specific markers, which were measured using Cytek™ Aurora spectral flow cytometry (Figure 2). The location of cells that are found in each cluster based on the highly expressed antigens are shown in the representative tSNE (viSNE) maps (Figure 2a). Compared to nonfunctional adenoma-derived hPITOs, organoids derived from corticotroph adenomas of CD patients highly expressed proliferating (Ki67+) T-Pit+ ACTH cells (Figure 2a). Interestingly, there was an increase in SOX2+ cells within the total cell population, associated with Crooke’s cell adenoma hPITOs (Figure 2a). Within the total cell population, cell clusters expressing CD45 and vimentin were also measured (Figure 2a). Data for the analysis of corticotroph hPITOs, derived from CD patients and individuals with nonfunctional adenomas, were summarized in a heatmap for each subtype organoid line based on quantified cell abundance (percent of total cells) using spectral flow cytometry (Figure 2b).
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Figure 2. Cell heterogeneity of corticotroph hPITOs. (a) viSNE maps define spatially distinct cell populations using pituitary specific cell lineage, stem cell, and transcription factor markers. Cell populations were quantified in organoids generated from CD patients with corticotroph adenomas (sparsely granulated and Crooke’s cell adenoma) or patients with nonfunctional corticotroph adenomas. (b) Quantification of the abundance of cells expressing pituitary specific markers as a percent total. viSNE maps define spatially distinct cell populations in organoid cultures generated from CD patient with (c) corticotroph adenoma (hPITO37, Crooke’s cell adenoma) and adjacent normal tissue (hPITO37N), or (d) sparsely granulated corticotroph adenomas (hPITO38) and adjacent normal tissue (hPITO38N).
Organoid cultures derived from pituitary adenomas (hPITO37 and hPITO38) were compared to organoids derived from adjacent normal pituitary tissue (hPITO37N and hPITO38N) (Figure 2c,d). While Pit1 lineages including cells expressing GH and PRL, as well as SF1 lineages expressing FSH and LH, were detected in the hPITO37N and hPITO38N organoid cultures, these cell populations were significantly reduced within the patient’s matched adenoma tissue (Figure 2c,d). Overall, hPITOs derived from CD patients expressed increased stem and progenitor cell markers, including CXCR4, SOX2, and CD133 (Figure 2). Collectively, our findings of the characterization of the hPITO cultures support our prediction that this in vitro model recapitulates much of the patient’s adenoma pathophysiology.

3.3. Inherent Patient Differences to Drug Response Is Reflected in the Organoid Culture

Tumor recurrence can occur in as many as 30–50% of CD patients after successful surgical treatment [10,33,34]. Unfortunately, bilateral adrenalectomy is the chosen surgical treatment for patients with persistent CD [35]. Bilateral adrenalectomy leads to the increased risk for development of Nelson’s syndrome (progressive hyperpigmentation due to ACTH secretion and expansion of the residual pituitary tumor). Although the risk of developing Nelson’s syndrome following adrenalectomy can be reduced by 50% with stereotactic radiotherapy [35], there is a need to develop medical therapies that directly target the pituitary adenoma. Thus, we established a high-throughput drug screening assay using patient-derived PitNET organoids. After 72 h of treatment, cell viability was measured using an MTS assay, and data were represented as a heatmap whereby blue indicated higher cell death, and red suggested higher cell viability. The replicates behaved consistently with the drug response, with correlation scores of >0.8 for these samples (Figure 3a). We estimated the variance component for each drug across all organoids. Variation among samples was found to be significant (p ≤ 0.05) for each of the 83 drugs. The drug responses were grouped by variance factor into large, median, and small. The larger the variance, the more variable the drug response was across the organoids. We noted a set of drugs that showed a significant differential response across the functional corticotroph organoids. Unsupervised clustering of drug responses across organoids shows a pattern that relates to our statistically calculated results (Figure 3a,c), and the replicates for each independent organoid cluster together. The drugs with higher variance components across all the functional corticotrophs cluster together as a group (Figure 3a). These drugs show cell viability of 10% to 60% across different organoids. Analyzing the pattern more closely, we observe that, within a pathologically defined group, there was a differential organoid response to drugs as well as inherent patient differences to drugs within this group. Figure 3 demonstrates a variation in drug responsiveness amongst the organoid lines generated from individual patients. Importantly, there was further divergence in drug responsiveness amongst the individual organoid lines within each pathologically defined corticotroph subtype. These data clearly demonstrate that the inherent patient difference to drug response which is often observed among CD patients is reflected in the organoid culture.
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Figure 3. Drug screen using hPITOs generated from CD patients. (a) High-throughput drug screening of hPITOs reveals sensitivities to a range of therapeutic agents. Cell viability with high values (indicating resistance) are depicted in red, and low values (indicating sensitivity) are in blue in the clustered heatmap. (b,c) Clusters showing response to therapeutic agents with the most variance across the organoids. (d) Network of drugs from the clusters b and c and their gene targets, showing their participation in signaling pathways and cellular processes.
Drugs that clustered together and showed correlated responses were investigated further for their mode of action based on target genes (Figure 3d). The genes were analyzed for their associations in cellular pathways and gene ontology functional processes. Identified drug–gene pairs were interconnected by cellular pathways that are known to regulate cell cycle, WNT signaling, hedgehog signaling, and neuroactive ligand-receptor interaction signaling pathways (Figure 3d). These identified genes are also known to be influenced by multiple cellular functions, such as cytokine–cytokine receptor interactions and Notch signaling. Proteosome 20S subunit genes PSMAs/PSMBs and the HDAC gene family are involved in many cellular functions. The ephrin receptors (EPHs), adrenoceptor alpha receptors (ADRs), dopamine receptors (DRDs), and the 5-hydroxytryptamine serotonin receptors (HTRs) gene families influence neuronal functions and are targeted by multiple drugs in our focused cluster. These data reveal potential therapeutic pathways for CD patients.
Divergent half maximal inhibitory concentration (IC50) values, as documented by an MTS cell viability assay, were observed in response to drug treatment among hPITOs lines 28, 33, 34, 35, and 37. Note that a shift of the curve to the right indicates a higher IC50 (i.e., more resistant to that drug). Cell viability assays were normalized to vehicle-treated controls in order to ensure that toxicity was specific to the drug effects (Figure 4). Dose response curves for organoid 33 and organoid 34 showed better responses at lower doses for cabergoline compared to Metyrapone and osilodrostat, but different for organoid 35, where Metyrapone and osilodrostat gave better responses than Cabergoline (Figure 4a–h). For the drugs mifepristone and GANT61, 33 and 34 had the same level of response to both the drugs. However, when the two organoid responses were compared, 34 had a better response than 33 (Figure 4a–h). Similar divergent drug responses were observed in hPITO lines 37 and 38 (Figure 4i,k). However, organoids generated from adjacent normal pituitary tissue from patients 37 and 38 were nonresponsive to the same standard of care of investigational drugs for CD (Figure 4j,l). These data were consistent with observation made in the drug screen (Figure 3a–c), and demonstrate that there was an inherent difference to drug response within the organoid cultures of the same corticotroph subtype.
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Figure 4. Drug dose responses by hPITOs generated from CD patients. Dose responses to mifepristone, GANT61, cabergoline, and osilodrostat. (a,e) hPITO28, (b,f) hPITO33, (c,g) hPITO34, and (d,h) hPITO35. Dose responses to cabergoline, ketoconazole, roscovitine, GANT61, pasireotide, mifepristone, etomidate, mitotane, metyrapone, and osilodrostat in (i) hPITO37, (j) organoids generated from adjacent normal pituitary tissue (hPITO37N), (k) hPITO38, (l) hPITO38N, and (m) hPITO39. (n) IC50 and integrated area under the curve in response to mifepristone, ketoconazole, and pasireotide using hPITO39 cultures. Nuclear morphometric analysis of hPITO39 cultures in response to (o,p) vehicle, (q,r) mifepristone, (s,t) pasireotide, and (u,v) ketoconazole. Morphometric classification of NII was based on the normal (N), small (S), small regular (SR), short irregular (SI), large regular (LR), large irregular (LI), and irregular (I) nuclear morphology. Representative Hoechst staining of organoids in response to drug treatments for the calculation of the nuclear irregularity index (NII) are shown in the insets in (p,r,t,v).
In addition to cell viability, Nuclear Morphometric Analysis (NMA) using treated organoids was performed based on a published protocol that measures cell viability according to the changes in nuclear morphology of the cells, using nuclear stain Hoechst or DAPI [30]. Nuclear Irregularity Index (NII) was measured based on the quantification of the morphometric changes in the nuclei in response to the standard-of-care drugs mifepristone, pasireotide, and ketoconazole in hPITO39 (Figure 4o–v). The area vs. NII of vehicle-treated cells were plotted as a scatter plot using the template, and considered as the normal cell nuclei (Figure 4o). The same plots were generated for mifepristone (Figure 4q), pasireotide (Figure 4s), and ketoconazole (Figure 4u). The NII and area of treated cells were compared to those of the normal nuclei, and classified as one of the following NMA populations: Normal (N; similar area and NII), Mitotic (S; similar area, slightly higher NII), Irregular (I; similar area, high NII), Small Regular (SR; apoptotic, low area and NII), Senescent (LR; high area, low NII), Small Irregular (SI; low area, high NII), or Large Irregular (LI; high area, high NII) (Figure 4p,r,t,v). Cells classified as SR exhibited early stages of apoptosis, and cells classified as either I, SI, or LI exhibited significant nuclear damage. Data showed that mifepristone induced significant apoptosis in hPITO39 cultures (Figure 4r), compared to responses to pasireotide (Figure 4t) and ketoconazole (Figure 4v). These responses were consistent with the IC50 and the total area under the curve in response to drugs (Figure 4m,n). Measurement of NII is an approach which may be used to confirm potential drug targets identified from the drug screen.

3.4. Organoid Responsiveness to Pasireotide Correlates with SSTR2 and SSTR5 Expression

Organoid lines hPITO28, 31, 33, 34, and 35 exhibited divergent IC50 values in response to SSTR agonist pasireotide (Figure 5a). hPITO34 was the most responsive to pasireotide, with a low IC50 value of 6.1 nM (Figure 5a). Organoid lines hPITO33 and hPITO35 were the least responsive, with IC50 values of 1.2 µM and 1 µM, respectively, in response to pasireotide (Figure 5a). The expression of SSTR subtypes 1–5 among the different organoid lines were measured by qRT-PCR and IHC (Figure 5b). One of the least responsive organoid lines, hPITO28, exhibited lower differential expression in SSTR2 and SSTR5 compared to the highly responsive hPITO34 line (Figure 5a,b). Gene expression levels of SSTR2 and SSTR5 within hPITO28 and 34 correlated with protein levels within the patient’s tumor tissue (Figure 5c–f). Given the greater binding affinity for SSTR5 compared to SSTR2 by pasireotide, these data were consistent with greater responsiveness to the drug by hPITO34 in comparison to hPITO28 (Figure 5a,c–f). The expression of SSTR subtypes 2 and 5 within the organoid cultures correlated with the expression patterns of the patient’s tumor tissues (Figure 5a,c–f).
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Figure 5. SSTR1-5 expression in hPITOs and patient’s PitNET tissue. (a) Dose response of hPITO28, 31, 33, 34, and 35 lines to pasireotide. (b) Differential expression of SSTR subtypes 1–5 (SSTR1, SSTR2, SSTR3, SSTR4, SSTR5) in hPITO28, hPITO31, hPITO33, hPITO34, and hPITO35. Immunohistochemistry of (c,e) SSTR2 and (d,f) SSTR5 expression in patient PitNET tissue (Pt28 and Pt34), from which hPITO28 and 34 were generated.

3.5. Organoids Derived from Pituitary Corticotroph Adenomas Retain the Genetic Alterations of the Patient’s Primary Tumor

In order to identify the genetic features of the organoids derived from pituitary adenomas of CD patients, we performed whole-exome sequencing (WES) of hPITOs and the corresponding primary adenoma tissues. We performed WES analysis of each hPITO line, and compared the results with those for the corresponding primary adenoma tissues. We showed the concordance rate of exonic variants between the primary tumor tissues obtained from CD patients and the corresponding organoid line. We identified, on average, approximately 5000 mutations across each of the 14 paired samples of organoids and tissues. For the variants detected, all seven pairs showed a Jaccard index ranging from 0.5 to 0.8. Out of seven pairs, five (hPITO24, 25, 28 and 35) pairs had a Jaccard score of 0.8, while hPITO33 and 34 pairs had 0.7, and hPITO1 had 0.5. In order to investigate the similarity across the SNV (single nucleotide variation) sites, we calculated the Jaccard index of exon sites for synonymous and non-synonymous events, and found scores for all pairs ranging from 0.8 to 0.9. Furthermore, for only non-synonymous events, Jaccard scores also ranged from 0.8 to 0.9, except for hPITO1, which showed overall lower concordance, and had a score of 0.4 to 0.5. Figure 6 shows non-synonymous mutations found in organoid and tissue pairs for some of the key genes that are known to be involved in pituitary adenoma disease. Concordance indices between organoids and the matched patient’s adenoma tissues is reported in Figure 6. Therefore, WES data demonstrated that organoids derived from pituitary corticotroph adenomas retained the genetic alterations of the patient’s primary tumor tissue.
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Figure 6. Genomic landscape of hPITOs recapitulates genetic alterations commonly found PitNETs. Overview of single nucleotide variation events detected in hPITOs in genes commonly altered in PitNETs. The mutation frequency across the organoid population is depicted on the right. Color coding of the figure shows that organoid lines are derived from the same patient tumor tissue. ORG: organoid line, TIS: matched patient’s PitNET tissue.

3.6. IPSC Pituitary Organoids Generated from a CD Patients Expressing Familial Mutations Reveal Corticotroph Adenoma Pathology In Vitro

Extensive research has revealed the role of somatic and germline mutations in the development of CD adenomas [36,37]. Pituitary organoids were developed from iPSCs generated from the PBMCs of CD patients and carrying germline mutations that were identified by WES (Supplemental Figure S4). Chromosomal aberrations were not found when comparing against the reference dataset in the iPSCs generated from the CD patients (Supplemental Figure S3a,b). PBMCs isolated from patients diagnosed with CD were analyzed by WES in order to determine the expression of germline mutations. WES revealed the expression of a more recently identified gene predisposing patients to CD, namely cadherin-related 23 [38] (Supplemental Figure S5).
Pituitary organoids were then developed from iPSCs which were generated from the PBMCs of patients with CD (iPSCCDH23 and iPSCMEN1) and a healthy individual (iPSCctrl). Expression of PIT1 (pituitary-specific positive transcription factor 1), ACTH (adrenocorticotropic hormone), GH (growth hormone), FSH (follicle-stimulating hormone), LH (luteinizing hormone), PRL (prolactin), and synaptophysin (synaptophysin) with co-stain Hoechst (nuclei, blue) was measured by immunofluorescence, using chamber slides collected at 15 of the differentiation schedules (Supplemental Figure S6). While pituitary tissue that was differentiated from iPSCctrl expressed all major hormone-producing cell lineages (Supplemental Figure S6a), there was a significant increase in the expression of ACTH and synaptophysin, with a concomitant loss of PIT1, GH, FSH, LH, and PRL in iPSCsMEN1 (Supplemental Figure S6b,c). Interestingly, iPSCCDH23 cultures exhibited a significant increase in the expression of ACTH, GH, LH, and synaptophysin, with a concomitant loss of PIT1, FSH, and PRL (Supplemental Figure S6b,c). Immunofluorescence of iPSCs collected on the fourth day of the differentiation schedule revealed no expression of PIT1, ACTH, GH, FSH, LH, or PRL in (data not shown). Compared to control lines, iPSC lines expressing mutated CDH23 secreted significantly greater concentrations of ACTH earlier in the differentiation schedule (Supplemental Figure S7a). The upregulated expression of pituitary corticotroph adenoma-specific markers in iPSCCDH23 and iPSCMEN1 demonstrates that the iPSC-derived organoids represented the pathology of corticotroph adenomas in vitro.

3.7. ScRNA-seq Reveals the Existence of Unique Proliferative Cell Populations in iPSCCDH23 Cultures When Compared to iPSCsctrl

Using Seurat to identify cell clusters, as well as Uniform Manifold Approximation and Projection 9UMAP, clustering analysis identified 16 distinct cell populations/clusters consisting of known marker genes. Clusters 1, 5, and 7 of the iPSCsCDH23 were distinct from the iPSCctrl cultures (Figure 7a,b). Pituitary stem cells were characterized in iPSCctrl and iPSCCDH23 cultures (Figure 7b). Clusters 1 and 5 expressed markers consistent with the corticotroph subtype cell lineage (Figure 5c). Markers of dysregulated cell cycles and increased proliferation were identified in cell cluster 7 (Figure 7c). Expression of the E2 factor (E2F) family of transcription factors, which are downstream effectors of the retinoblastoma (RB) protein pathway and play a crucial role in cell division control, were identified in distinct cell cluster 7, which was identified within the iPSCCDH23 cultures (Figure 7c). Stem cell markers were also upregulated in cell cluster 7, and identified within the iPSCCDH23 cultures (Figure 7c). Using Cytobank software to analyze organoids collected 30 days post-differentiation, cells were gated on live CK20 positive singlets, and 9000 events per sample were analyzed by the viSNE algorithm. ViSNE plots are shown in two dimensions with axes identified by tSNE- 1 and tSNE-2, and each dot representing a single cell positioned in the multidimensional space (Figure 7d). Individual flow cytometry standard files were concatenated into single flow cytometry standard files, from which 12 spatially distinct populations were identified (Figure 7e). Overlaying cell populations identified by traditional gating strategies onto viSNE plots identified unique cell populations within the iPSCCDH23 cultures (Figure 7e). There were distinct cell populations between the iPSCctrl and iPSCCDH23 organoids, in addition to expression of hormone and cell lineage markers such as ACTH, TPit, PRL, and PIT1 (Figure 7e). The cell populations that exhibited high expression of Ki67 within the iPSCctrl organoid cultures included SOX2+ and PIT1+ populations (Figure 7f). The highly proliferating cell populations within the iPSCCDH23 organoid cultures included those that expressed CD90+/VIM+/CXCR4+ (mesenchymal stem cells), CXCR4+/SOX2+ (stem cells), TPit+ (corticotroph cell lineage), CD133+/CD31+ (endothelial progenitor cells), and CK20+/VIM+/CXCR4+ (hybrid epithelial-mesenchymal stem cells) (Figure 7f). Overall, the iPSCCDH23 organoids were significantly more proliferative compared to the iPSCctrl cultures (Figure 7f). Immunofluorescence staining of iPSCCDH23 organoids revealed increased mRNA expression of TPit and POMC, which correlated with increased ACTH protein compared to iPSCsctrl (Supplemental Figure S6). As shown in Supplemental Figure S6b,c, iPSCCDH23 cultures also exhibited a significant increase in the expression of GH and LH (Supplemental Figure S6b,c).
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Figure 7. Single cell analysis of iPSCctrl and iPSCCDH23 cultures 15 and 30 days post-directed differentiation. (a) UMAP plots showing identified cell clusters 0–16 in iPSCctrl and iPSCCDH23 cultures 15 days post-directed differentiation. (b) Violin plots of representative identified markers of the corticotroph cell lineage, where 2 subpopulations were observed among iPSCctrl and iPSCCDH23 cultures. Arrows highlight clusters 1, 5, and 7. (c) Violin plots showing expression of genes representative of stem cells, Wnt, NOTCH, Hh and SST signaling, anterior pituitary (corticotroph) cell lineage, and cell cycle in clusters 1, 5, and 7 of iPSCCDH23 cultures. Plot width: cell number, plot height: gene expression. (d) viSNE maps showing concatenated flow cytometry standard files for both samples and iPSCctrl and iPSCCDH23 organoids 30 days post-directed differentiation. (e) Overlay of manually gated cell populations onto viSNE plots. (f) Fluorescent intensity of Ki67 of viSNE maps for both samples and iPSCctrl and iPSCCDH23 organoids. iPSCctrl = 22518 events; iPSCCDH23 = 17542 events.
Collectively, Figure 7 demonstrates that the development of pituitary organoids generated from iPSCs of CD patients may reveal the existence of cell populations which, potentially, contribute to the support of adenoma growth and progression, as well as an expansion of stem and progenitor cells that may be the targets for tumor recurrence.

4. Discussion

Our studies demonstrate the development of organoids generated from human PitNETs (hPITOs) can potentially be used to screen for the sensitivity and efficacy of responses to targeted therapies for CD patients that either fail to achieve remission or exhibit recurrence of disease after surgery. In addition, we have documented that induced pluripotent stem cells (iPSCs) generated from a CD patient expressing germline mutation CDH23 (iPSCCDH23) reveals the disease pathogenesis under directed differentiation. Many early in vitro experiments have used pituitary cell lines, spheroids, aggregates, and/or tumoroids that do not replicate the primary PitNET microenvironment [19,20,21], and lack a multicellular identity [39,40]. The development of PitNET tissue-generated organoids is limited to the use of transgenic mouse models as the source [22,23,41]. The recent organoid cultures reported by Nys et al. [42] have been generated from single stem cells isolated from PitNET tissue, and are claimed to be true organoids due to their clonality. However, multicellular complexity was not validated by the protein expression or hormone secretion from pituitary cell lineages in these cultures [42]. According to the National Cancer Institute (NCI, NIH), an ‘organoid’ is defined as “a tiny, 3-dimensional mass of tissue that is made by growing stem cells (cells from which other types of cells develop) in the laboratory” [43]. The hPITOs reported here begin from single and/or 3–4 cell clusters dissociated from the PitNET tissue that harbors the stem cells. Supplemental Video S2 demonstrates a process of ‘budding,’ as well as lumen formation as organoids grow and differentiate. We document differentiation and function by comprehensive spectral flow cytometry, ELISA, and response to standard of care drugs. The growth of PitNET organoids reported in the current study is consistent with that of gastrointestinal tissue derived cultures that begin from cell clusters, crypts, or glands [27,44,45].
Our studies report a PitNET tissue organoid culture with a multicellular identity consisting of differentiated cell lineages, stem/progenitor cells, and immune and stromal cell compartments, which replicates much of the patient’s own adenoma pathology, functionality, and complexity. We have also demonstrated that iPSCs, derived from the blood of a CD patient, can be directly differentiated into pituitary organoids that resemble similar characteristics to the tumor tissue. Many investigators have proposed the use of organoids in personalized medicine, but have focused these efforts on targeted treatment of cancers [27,46,47,48]. The findings reported in these studies are the first to implement this approach for the potential treatment of PitNETs. Collectively, we have developed a relevant human in vitro approach to potentially advance our knowledge as well as our approach to studies in the field of pituitary tumor research. Both the hPITOs and the iPSCCDH23 may be implemented in studies that strive to (1) define the molecular and cellular events that are crucial for the development of PitNETs leading to CD, and (2) accelerate the identification of effective targeted therapies for patients with CD.
While published studies have advanced our understanding of the molecular mechanisms of the pathogenesis of corticotroph adenomas and elucidated candidate therapeutic targets for CD, these reports fall short of directly informing clinical decisions for patient treatment. Using organoids to screen potential drugs and compounds can potentially improve therapeutic accuracy. Figure 3 demonstrated a variation in drug responsiveness amongst the organoid lines generated from individual patients. Importantly, there was further divergence in drug responsiveness amongst the individual organoid lines within each pathologically defined corticotroph subtype. For example, hPITOs generated from patients with sparsely granulated corticotroph adenomas (hPIT0s 10, 25, 34, 35) and Crooke’s cell adenomas (hPITOs 7, 33) showed variable responses regardless of similar pathologically defined subtypes. In addition, the response of the tumor cells within the organoids to the standard of care drugs that directly target the pituitary in the body, including mifepristone and cabergoline, was only 50% in hPITO34 and hPITO35, and almost 0% in the other lines, including hPITO7, 10, and 25. These data clearly demonstrate that the inherent patient difference to drug response that is often observed among CD patients is reflected in the organoid culture. This culture system may be an approach that will provide functional data revealing actionable treatment options for each patient. Patient-derived organoids from several tumors have served as a platform for testing the efficacy of anticancer drugs and predicting responses to targeted therapies in individual patients [27,46,48,49,50]. An example of the use of organoids in identifying drug responsiveness within an endocrine gland is that of papillary thyroid cancer [51]. Organoids developed from PTC patients were used as a preclinical model for studying responsiveness to anticancer drugs in a personalized approach [51]. However, our study is the first report of the use of hPITOs for drug screening. Connecting genetic and drug sensitivity data will further categorize corticotroph subtypes associated with CD. WES analysis of each hPITO line was compared to the results for the corresponding primary adenoma tissues. We showed the concordance rate of exonic variants between the primary tumor tissues obtained from CD patients and the corresponding organoid line. On average, approximately 80% of the variants observed in the CD patients’ adenoma tissues were retained in the corresponding hPITOs.
Pituitary organoids were also developed from iPSCs generated from PBMCs of a CD patient expressing a germline genetic alteration in cadherin-related 23 CDH23 (iPSCCDH23), a CD patient expressing an MEN1 mutation (iPSCMEN1), and a healthy individual (iPSCctrl). Foundational studies performed by investigators at the genome level have revealed significant knowledge regarding the pathophysiology of CD [36,37,52,53]. In some instances, CD is a manifestation of genetic mutation syndromes that include multiple endocrine neoplasia type 1 (MEN1), familial isolated pituitary adenoma (FIPA), and Carney complex [54,55]. CDH23 syndrome is clinically associated with the development of Usher syndrome, deafness, and vestibular dysfunction [56]. Several mutations in CDH23 are associated with inherited hearing loss and blindness [57]. However, none of the variants found in this study were linked to any symptoms of deafness or blindness. A possible explanation is that deafness-related CDH23 mutations are caused by either homozygous or compound heterozygous mutations [57]. In a study that linked mutations in CDH23 with familial and sporadic pituitary adenomas, it was suggested that these genetic alterations could play important roles in the pathogenesis of CD [38]. Genomic screening in a total of 12 families with familial PitNETs, 125 individuals with sporadic pituitary tumors, and 260 control individuals showed that 33% of the families with familial pituitary tumors and 12% of individuals with sporadic pituitary tumors expressed functional or pathogenic CDH23 variants [38]. Consistent with the expected pathology and function of a PitNET from a patient with CD, iPSCCDH23 organoids exhibited hypersecretion of ACTH, and expression of transcription factors and cell markers were reported in the pathology report for corticotroph PitNETs. Collectively, these findings warrant further investigation to determine whether carriers of CDH23 mutations are at a high risk of developing CD and/or hearing loss. Specifically, clinical investigation is required to determine whether pituitary MRI scans should be adopted in the screening of CDH23-related diseases, including Usher syndrome and age-related hearing loss.
Pituitary organoids generated from iPSCs of a CD patient revealed the existence of cell populations that potentially contribute to the support of PitNET growth and disease progression, as well as an expansion of stem and progenitor cells that may be the targets for tumor recurrence. Organoids derived from both pituitary adenomas and iPSCs exhibited increased expression of stem cell and progenitor markers at both the protein and transcriptomic levels. Unique clusters that were proliferative in the iPSCCDH23 organoids expressed a hybrid pituitary cell population which was in an epithelial/mesenchymal state (CK20+/VIM+/CXCR4+/Ki67+). In support of our findings, a similar report of a hybrid epithelial/mesenchymal pituitary cell has been made as part of the normal developmental stages of the human fetal pituitary [58]. Previous studies have suggested that pituitary stem cells undergo an EMT-like process during cell migration and differentiation [59,60,61]. Consistent with our findings are extensive studies using single cells isolated from human pituitary adenomas to show increased expression of stem cell markers SOX2 and CXCR4 [22,23,41,62,63]. Within the clusters identified in the iPSCCDH23 culture were cell populations expressing stem cell markers, including SOX2, NESTIN, CXCR4, KLF4, and CD34. The same iPSCCDH23 cell clusters, 4, 8, 9, and 11, co-expressed upregulated genes of NOTCH, Hedgehog, WNT, and TGFβ signaling, which are pivotal not only in pituitary tumorigenesis and pituitary embryonic development, but also in ‘tumor stemness’ [22,23,41,62,63,64]. We also noted that clusters of cell populations 5 and 14 unique within the iPSCCDH23 cultures expressed upregulated genes which were indicative of high proliferation. We observed upregulated expression of the E2F family of transcription factors (E2Fs) E2F1 and E2F7. These findings are of significance, given that there is evidence to show that upregulation of E2Fs is fundamental for tumorigenesis, metastasis, drug resistance, and recurrence [65]. Within the pituitary adenoma microenvironment, whether these stem cells directly differentiate into pituitary tumors or support the growth of the adenoma is largely unknown. In addition, whether pituitary stem cell populations become activated in response to injury is also understudied. Although the role of stem cells has been identified using a mouse model through implantation of the cells within the right forebrain [66], the identification of pituitary tumor-initiating stem cells using in vivo orthotopic transplantation models is impossible in mice. Pituitary tumors harboring the stem cells may require engraftment within the environment from which the cells are derived in order to enable growth and differentiation of the tumor. However, it is technically impossible to implant cells orthotopically in the murine pituitary. The pituitary tumor organoid cultures presented in these studies may offer an approach by which isolation, identification, and characterization of this stem cell population is possible. Therefore, we would gain knowledge on the mechanisms of pituitary tumor pathogenesis and reveal potential novel targets for therapeutic interventions by using the iPSC generated pituitary organoid culture.
PitNETs associated with the development of CD cause serious morbidity due to chronic cortisol exposure that dysregulates almost every organ system in the body. Overall, existing medical therapies remain suboptimal, with negative impact on health and quality of life, including considerable risk of therapy resistance and tumor recurrence. To date, little is known about the pathogenesis of PitNETs. Here, we present a human organoid-based approach that will allow us to acquire knowledge of the mechanisms underlying pituitary tumorigenesis. Such an approach is essential to identify targeted treatments and improve clinical management of patients with CD.

5. Conclusions

Cushing’s disease (CD) is a serious endocrine disorder caused by an adrenocorticotropic hormone (ACTH)-secreting pituitary neuroendocrine tumor (PitNET), which stimulates the adrenal glands to overproduce cortisol. The absence of preclinical models that replicate the PitNET microenvironment has prevented us from acquiring the knowledge to identify therapies that can be targeted to the tumor with a higher efficacy and tolerability for patients. Our studies demonstrate the development of organoids generated from human PitNETs or induced pluripotent stem cells as an essential approach to identifying targeted therapy methods for CD patients.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/cells11213344/s1, Figure S1: Antibodies used and Cytek® Full Spectrum Viewer showing calculated similarity indices; Figure S2: Morphology and proliferation of lactotroph, somatotroph, and gonadotroph hPITOs; Table S1: Pituitary Growth Media; Table S2: Components used for pituitary organoids generated from iPSCs; Table S3: clinical characteristics of pituitary adenoma samples used for the generation of organoids; Table S4: Average correlation of replicates reported in Figure 3; Table S5: pituitary cell lineage or stem cell markers used in the scRNA-seq analysis; Video S1: hPITO38 EdU ACTH 3.

Author Contributions

Conceptualization, Y.Z.; methodology, J.C., Y.Z., J.M.C., B.N.S., S.M. and K.W.P.; software, J.C., Y.Z., J.M.C., S.M., Y.C., P.M. and R.P.; validation, Y.Z., J.C., J.M.C., A.S.L., K.C.J.Y. and R.P.; formal analysis, J.C., Y.Z., J.M.C., R.P., Y.C., S.M. and P.M.; investigation, Y.Z.; resources, Y.Z., J.C., J.E., C.A.T., B.H. and A.S.L.; data curation, J.C., Y.Z., J.M.C., R.P. and S.M.; writing—original draft preparation, Y.Z., J.C, S.M., J.M.C., Y.C., B.H. and R.P.; writing—review and editing, Y.Z., J.C., J.M.C., A.S.L., K.C.J.Y., S.M., J.E., C.A.T., K.W.P., B.H., Y.C., P.M., B.N.S. and R.P.; visualization, Y.Z., J.C., J.M.C., A.S.L., K.C.J.Y. and R.P.; supervision, Y.Z.; project administration, Y.Z.; funding acquisition, Y.Z. All authors have read and agreed to the published version of the manuscript.

Funding

This research was supported by the Department of Cellular and Molecular Medicine (University of Arizona College of Medicine) startup funds (Zavros). This research study was also partly supported by the National Cancer Institute of the National Institutes of Health under award number P30 CA023074 (Sweasy).

Institutional Review Board Statement

The study was conducted in accordance with the Declaration of Helsinki and approved by the Institutional Review Board of St. Joseph’s Hospital and Barrow Neurological Institute Biobank collection protocol PHXA-05TS038, and collection of outcomes data protocol PHXA-0004-72-29, and patient consent (protocol date of approval).

Informed Consent Statement

Written informed consent was obtained from all subjects involved in the study.

Data Availability Statement

The datasets generated during the analysis of the present study are available in the ReDATA repository, https://doi.org/10.25422/azu.data.19755244.v1. The datasets generated in the current study are also available from the corresponding author on reasonable request. All data generated or analyzed during this study are included in this published article (and its Supplementary Information Files).

Acknowledgments

We acknowledge the technical support of Maga Sanchez in the Tissue Acquisition and Cellular/Molecular Analysis Shared Resource (TACMASR University of Arizona Cancer Center) for assistance with embedding and sectioning of organoids. We would also like to acknowledge Patty Jansma (Marley Imaging Core, University Arizona) and, Douglas W Cromey (TACMASR imaging, University of Arizona Cancer Center) for assistance in microscopy. The authors thank the patients who consented to donate pituitary tumor tissues and blood for the development of the organoids. Without their willingness to participate in the study, this work would not be possible.

Conflicts of Interest

The authors declare no conflict of interest.

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Pasireotide-Induced Shrinkage in GH and ACTH Secreting Pituitary Adenoma

Introduction: Pasireotide (PAS) is a novel somatostatin receptor ligands (SRL), used in controlling hormonal hypersecretion in both acromegaly and Cushing’s Disease (CD). In previous studies and meta-analysis, first-generation SRLs were reported to be able to induce significant tumor shrinkage only in somatotroph adenomas. This systematic review and meta-analysis aim to summarize the effect of PAS on the shrinkage of the pituitary adenomas in patients with acromegaly or CD.

Materials and methods: We searched the Medline database for original studies in patients with acromegaly or CD receiving PAS as monotherapy, that assessed the proportion of significant tumor shrinkage in their series. After data extraction and analysis, a random-effect model was used to estimate pooled effects. Quality assessment was performed with a modified Joanna Briggs’s Institute tool and the risk of publication bias was addressed through Egger’s regression and the three-parameter selection model.

Results: The electronic search identified 179 and 122 articles respectively for acromegaly and CD. After study selection, six studies considering patients with acromegaly and three with CD fulfilled the eligibility criteria. Overall, 37.7% (95%CI: [18.7%; 61.5%]) of acromegalic patients and 41.2% (95%CI: [22.9%; 62.3%]) of CD patients achieved significant tumor shrinkage. We identified high heterogeneity, especially in acromegaly (I2 of 90% for acromegaly and 47% for CD), according to the low number of studies included.

Discussion: PAS treatment is effective in reducing tumor size, especially in acromegalic patients. This result strengthens the role of PAS treatment in pituitary adenomas, particularly in those with an invasive behavior, with progressive growth and/or extrasellar extension, with a low likelihood of surgical gross-total removal, or with large postoperative residual tissue.

Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022328152, identifier CRD42022328152

Introduction

Pasireotide (PAS) is a novel somatostatin receptor ligand (SRL) with a high affinity for the somatostatin receptor (SSR) type 5 (12). Somatotroph adenomas are usually responsive to first-generation SRLs (octreotide and lanreotide), as they are able to reduce growth hormone (GH) secretion through SSR type 2 (3). In the flow-chart of acromegaly treatment, PAS is suggested in case of resistance to first-generation SRLs, as SSR type 5 is also abundantly expressed in GH-secreting adenomas (3). A phase III study with PAS long-acting release (LAR) proved its efficacy in first-generation SRLs-resistant acromegalic patients after 6 months (4). In the extension study (Colao A et al.), 37% of patients achieved normalization of insulin-like growth factor 1 (IGF-1) and/or GH levels <1 µg/L, considering both those performing the extension treatment and those crossing over from the first-generation SRL-control group to the PAS LAR group. Nearly two-thirds of responses were achieved after at least 6 months of treatment. Up-titration of the dose from 40 to 60 mg monthly enriched the number of responders, suggesting that the PAS LAR effect may be both time- and dose-dependent (5). Concomitant improvement in signs and symptoms has also been confirmed in other series (69).

SSR type 5 is the predominant isoform in human corticotroph adenomas, since it is not down-regulated by high cortisol levels, as SSR type 2 does. Therefore, PAS is the only SRL available in patients with Cushing’s Disease (CD) (2). In a phase III study, subcutaneous (s.c.) PAS proved to be effective in normalizing urinary free cortisol (respectively in 13% and 25% of patients taking 600 µg or 900 µg bis-in-die for 12 months) (10), achieving significant clinical improvement (11). In the same clinical setting, PAS LAR showed similar efficacy and safety profiles (12). These benefits could be maintained for up to 5 years in an extension study (1314). In a recent meta-analysis, PAS treatment provided disease control in 44% of 522 patients with CD (15). Patients harbouring USP-8 mutations demonstrated an increased SSR type 5 expression in the corticotroph adenoma, increasing the likelihood of a positive response to PAS therapy (16). The safety profile of PAS is similar to that of first-generation SRLs, except for a significant worsening in glucose homeostasis (17).

Despite the normalization of hormonal excess, another goal of the medical treatment in GH-secreting pituitary adenomas is the reduction of the size of the adenoma (18). First-generation SRLs proved to be effective in achieving tumor shrinkage in acromegaly: Endocrine Society clinical practice guidelines suggested their role as primary therapy in poor surgical candidates and in those with extrasellar extension without chiasmal compression (18). Cozzi et al. reported in a large prospective cohort of acromegalic patients a significant Octreotide-induced tumor shrinkage in 82% of those receiving SRL as first-line treatment; most of them exhibited an early shrinkage with a progressive trend in reduction later on (19). A meta-analysis of 41 studies reported a significant tumor shrinkage in 50% of included patients (20). Data from the primary treatment with once-monthly lanreotide in surgical naïve patients demonstrated its efficacy in reducing tumor volume, achieving significant tumor shrinkage in 63% of them (21). Hypo-intensity on T2-weighted sequences at baseline magnetic resonance imaging (MRI) seems to predict tumor volume reduction during first-generation SRLs treatment (22). Regarding patients with CD, most patients presented a microadenoma, usually not aggressive or invasive: only in selected cases tumor shrinkage is an aim to achieve in patients with corticotropinoma.

As available data are scarce (or limited to selected studies), and the issue of pituitary adenoma shrinkage is of primary importance in the management of tumors that cannot be addressed through surgery, the aim of this systematic review and meta-analysis is to summarize available data regarding the effect of PAS on tumor size.

Materials and Methods

We used the Population-Intervention-Comparison-Outcome (PICO) model to formulate the research questions for the systematic review (23), as summarised in Figure 1. The systematic review and meta-analysis were conducted and are reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis of Diagnostic Test Accuracy Studies (PRISMA-DTA) statement (24). We registered the protocol on the International Prospective Register of Systematic Reviews database (PROSPERO, https://www.crd.york.ac.uk/PROSPERO, number CRD42022328152).

Figure 1
www.frontiersin.orgFIGURE 1 PICO (Population-Intervention-Comparison-Outcome) model design to our study.

Search Strategy

An extensive Medline search was performed for the research question by two of the authors (F.C. and A.M.) independently, discrepancies were resolved by discussion. The literature search was performed up to January 2022, no language restriction was applied. Research included the following keywords: 1) (“acromegalies” [All Fields] OR “acromegaly”[MeSH Terms] OR “acromegaly”[All Fields]) AND (“pasireotide”[Supplementary Concept] OR “pasireotide”[All Fields]); 2) (“pituitary ACTH hypersecretion”[MeSH Terms] OR (“pituitary”[All Fields] AND “ACTH”[All Fields] AND “hypersecretion”[All Fields]) OR “pituitary ACTH hypersecretion”[All Fields]) AND (“pasireotide”[Supplementary Concept] OR “pasireotide”[All Fields]).

Inclusion and exclusion criteria were specified in advance and protocol-defined, in order to avoid methodological bias for post-hoc analysis. The searches were designed to select all types of studies (retrospective, observational, controlled, randomized, and non-randomized) conducted in patients with acromegaly or CD treated with PAS as monotherapy; the assessment of the proportion of significant tumor shrinkage was an inclusion criterion. Search terms were linked to Medical Subject Headings when possible. Keywords and free words were used simultaneously. Additional articles were identified with manual searches and included a thorough review of other meta-analyses, review articles, and relevant references. Consolidation of studies was performed with Mendeley Desktop 1.19.8.

Study Selection

We included all original research studies conducted in adult patients that underwent PAS treatment used as monotherapy (s.c. bis-in-die and intramuscular once/monthly), that provided sufficient information about tumor size reduction during treatment. In case of overlapping cohorts of patients (as clinical trials with core and extension phases), we included only the extension study, in order to select those patients with measurable tumor shrinkage after long-term treatment. Local reports regarding patients involved in multicenter trials were excluded from the analysis, as they had been already considered in the larger series. Reviewers were not blinded to the authors or journals when screening articles.

Data Extraction and Quality Assessment

Two authors (F.C. and A.M.) read the included papers and extracted independently relevant data, any disagreements were resolved by discussion. If data were not clear from the original manuscript, the authors of the primary study were contacted to clarify the doubts.

Contents of data extraction in the selected paper included: name of the first author, year of publication, setting (referral centre, academic hospital, mono- or multi-centric collection), type of treatment, its dose schedule and duration, pituitary imaging method during follow- up, the endpoint type regarding adenoma size analysis (i.e. primary vs exploratory). When data were reported for each patient or for subgroups, a global percentage of significant tumor shrinkage was calculated considering all subjects involved in the study.

To assess the risk of bias in the included studies, the critical appraisal tool from Joanna Briggs’s Institute (JBI) was adapted to evaluate those considered in our metanalysis (25). Among the items proposed, we selected the most appropriate to our setting: 1. Were the inclusion criteria clearly identified? 2. Were diagnostic criteria for acromegaly or CD well defined? 3. Were valid methods applied to evaluate tumor shrinkage? 4. Was the inclusion of participants consecutive and complete? 5. Was the reporting of baseline participants’ features (demographic and clinical) complete? 6. Was the report of the outcomes clear? 7. Was the report of demographics of the involved sites complete? 8. Was statistical analysis appropriate? For each aspect we assigned as possible choices of answer: yes, no or unclear.

Data Synthesis and Analysis

A qualitative synthesis was performed summarizing the study design and population characteristics (age, male to female ratio, macro- to micro-adenoma ratio, prior treatments).

A random-effect model was used to estimate pooled effects. Forest plots for percentages of significant tumor size reduction were generated to visualize heterogeneity among the studies. In order to assess publication bias, despite the low number of articles considered, we performed funnel plot and asymmetry analysis adjusted for the low number of studies (an Egger’s regression test and a three-parameter selection model where two tailed p < 0.05 was considered statistically significant). The I2 test was conducted to analyze the heterogeneity between studies: an I2 >50% indicated a between-study heterogeneity.

Statistical analyses were performed with R: R-4.1.2 for Windows 10 (32/64 bit) released 2021-11-01 and R studio desktop RStudio Desktop 1.4.1717 for Windows 10 64 bit (R Foundation for Statistical Computing, Vienna, Austria, URL https://www.R-project.org/).

Results

Study Selection

The study selection process for acromegaly is depicted in Figure 2. The electronic search revealed 179 articles, with one duplicate (N = 178). After the first screening, 141 articles did not meet the eligibility criteria and were discarded. The full-text examination of the remaining studies excluded additional 31 articles: 27 did not provide adequate data about tumor size, two represented the core phase of an extension study, another one referred to a subset of patients from a larger study, and the last one did not provide sufficient data about the percentage of tumor size reduction. Thus, six studies fulfilling eligibility criteria (reported in Tables 12), were selected for data extraction and analysis.

Figure 2
www.frontiersin.orgFIGURE 2 Search strategy for acromegaly. * Petersenn S, 2010 (PAS sc, phase II) and Colao A, 2014 (PAS LAR). ** Shimon I, 2015 (PAS LAR). *** Tahara S, 2019 (PAS LAR, phase II). PAS, pasireotide, sc, subcutaneous, LAR, long-acting release.

Table 1
www.frontiersin.orgTABLE 1 Studies considered for the metanalysis in acromegaly.

Table 2
www.frontiersin.orgTABLE 2 Studies considered for the metanalysis in acromegaly.

The study selection process for CD is depicted in Figure 3. The electronic search revealed 122 articles; an additional one had been included post-hoc, through reference analysis of selected articles (N = 123). After the first screening, 91 articles did not meet the eligibility criteria and were discarded. The full-text examination of the remaining studies excluded 29 more articles: 23 did not provide sufficient data on tumor shrinkage, two of them represented the core phase of extension studies, two referred to subsets of patients included in a larger study and two did not provide sufficient data regarding the percentage of tumor size reduction. Thus, three studies fulfilling eligibility criteria (reported in Tables 34) were selected for data extraction and analysis.

Figure 3
www.frontiersin.orgFIGURE 3 Search strategy for Cushing’s Disease. * Lacroix A, 2018 (PAS LAR, phase III) and Lacroix A, 2020 (PAS sc, phase III post-hoc analysis). ** Simeoli C, 2014 (PAS sc) and Colao A 2012 (PAS sc, phase III). *** Daniel E, 2018 (PAS sc and LAR) and Trementino L, 2016 (PAS sc). PAS, pasireotide, sc, subcutaneous, LAR, long acting release.

Table 3
www.frontiersin.orgTABLE 3 Studies considered for the metanalysis in Cushing’s Disease.

Table 4
www.frontiersin.orgTABLE 4 Studies considered for the metanalysis in Cushing’s Disease.

Study Characteristics

Four multi- and two mono-centric studies in patients with acromegaly were considered and analyzed, all presenting a prospective design. Tumor size analysis was not one of the primary endpoints in any of the considered studies; from an initial overall recruitment of 358 patients, only 265 were included for tumor size reduction analysis. Most patients had previously undergone different treatments (Table 1). All studies, except one, used PAS LAR, dose titration was allowed in all trials. Median follow-up ranged from 6 to 25 months; MRI was performed to evaluate tumor size reduction and the criteria for considering it significant was mainly based on tumor volume analysis, except for Lasolle H et al. which considered median height reduction (26). Data from the PAOLA study provided separate percentages of significant tumor shrinkage for PAS at 40 mg or 60 mg once monthly; considering that respectively 12 and 7 patients showed a reduction >25%, a significant shrinkage was reported in 19 out of 79 considered cases (24%) (4). Stelmachowska-Banás et al. described one patient with McCune-Albright’s syndrome presenting with pituitary hyperplasia, without a visible adenoma at MRI; as its pituitary volume decreased during treatment, the patient was included in the group with significant tumor shrinkage (27). No study provided information about macro- to micro-adenoma ratio. Data regarding age and male to female ratio are also reported in Table 2.

Three studies including patients with CD met the eligibility criteria (Tables 34); all of them presented a multicentre prospective design, recruiting 139 patients, most of them assuming PAS as a second-line treatment, after a surgical failure. For tumor shrinkage analysis, a subgroup of 34 patients was considered, taking s.c. PAS bis-in-die in two studies and PAS LAR in the third; in all cases titration was admitted. Tumor size analysis was a secondary endpoint in all three studies. Follow-up ranged from 6 to 60 months; tumor size assessment was performed with pituitary MRI. Only Pivonello et al. evaluated maximum diameter, instead of tumor volume changes (28). The population analyzed for tumor shrinkage mainly presented with a microadenoma. Data regarding age and gender are reported in Table 4. In the trial reported by Petersenn S et al., we arbitrarily fixed the criterion to define a significant tumor volume reduction (at least 25% of the baseline size of the pituitary adenoma), and the proportion of responders was calculated from the supplementary materials accordingly (3/6 = 50%) (13). Pivonello et al. separated patients exhibiting mild-moderate from those with severe hypercortisolism; we considered them together for tumor size analysis obtaining an overall proportion of significant size reduction of 21.4% (3 out of 14 subjects) (28).

Risk of Bias

The evaluation of the risk of bias performed with the adapted JBI tool is reported in Table 5. All studies presented clear diagnostic and inclusion criteria, except that of Lasolle H et al. (26). Although all papers reported a valid tool for tumor shrinkage analysis (MRI), two of them did not analyse tumor volume and did not provide a clear definition of significant size reduction (2628). Regarding other items, the majority of the considered studies did not appear to present a clear source of bias.

Table 5
www.frontiersin.orgTABLE 5 Evaluation of the risk of bias performed with the adapted Joanna Briggs’s Institute (JBI) tool.

Meta-Analysis

In the six studies considered for acromegaly, 37.7% (95%CI: [18.7%; 61.5%]) of patients demonstrated a significant tumor size reduction (Figure 4). As expected, heterogeneity in tumor reduction between studies was high (I2 = 90%). We attempted to address publication bias despite the low-number of studies (Figure 6A): Egger’s regression test did not indicate the presence of funnel plot asymmetry (intercept = -3.15 with 95%CI: [-10.17; 3.85], t = -0.883, p = 0.427) and the three-parameter selection model performed for p < 0.05 (and p < 0.1 as a sensitivity analysis) suggested absence of publication bias (28).

Figure 4
www.frontiersin.orgFIGURE 4 Pooled effect for the proportion of responders (i.e. presenting significant tumor shrinkage) in acromegaly. CI, confidence interval.

In the three studies considered for CD, 41,2% (95%CI: [22.9%; 62.3%]) of patients overall demonstrated a significant tumor size reduction (Figure 5). The heterogeneity in tumor reduction between the studies represented by I2 amounted to 47%. Publication bias analysis (Figure 6B) was performed using Egger’s regression test (intercept = -1.828 with 95%CI: [-14.53; 10.88], t = -0.282, p = 0.825) without evidence of asymmetry. The three-parameter selection model on the contrary could not be performed due to the small number of studies.

Figure 5
www.frontiersin.orgFIGURE 5 Pooled effect for the proportion of responders (i.e. presenting significant tumor shrinkage) in Cushing’s Disease. CI, confidence interval.

Figure 6
www.frontiersin.orgFIGURE 6 (A) Funnel plot assessing publication bias for Acromegaly. (B) Funnel plot assessing publication bias for Cushing’s Disease.

Discussion

The biochemical efficacy of medical treatment with PAS in GH- or ACTH-secreting pituitary adenomas has been described in previous metanalyses for acromegaly (2930) and CD (15), the latter also exploring the clinical benefit. In addition to these reports, this meta-analysis shows that PAS treatment can induce an additional clinically significant tumor shrinkage in approximately 40% of patients.

Acromegaly

Overall, PAS treatment provided tumor shrinkage in 37.7% of the considered patients. A previous metanalysis on octreotide in acromegaly provided a higher percentage of tumor size reduction (over 50%) (20). Nevertheless, since PAS treatment is usually considered as a second- or third-line treatment in the therapeutic flow-chart of acromegaly, the population recruited is mainly composed of patients with first-generation SRL-resistant somatotroph adenomas. This bias in recruited populations of acromegalic patients may explain this difference in the outcome. In a direct comparison, although PAS LAR seemed more effective in achieving biochemical control, both the SRLs, the first- and the second-generation types, achieved similar percentages of tumor shrinkage (67). Moreover, in the crossover extension, the switch from octreotide to PAS was more effective than the reverse schedule, achieving a slightly higher percentage of further significant tumor shrinkage (8). Lasolle et al. reported that the expression of SSR type 5 and the granulation pattern are of limited value for the prediction of PAS responsiveness: 5 out of 9 somatotropinomas in their series were densely granulated (two did not respond to PAS), and the expression of SSR type 5 was modest in one controlled patient (26).

Other than SRLs, a further therapeutic option targeting the somatotroph adenoma is cabergoline, either as monotherapy in mild cases or as an add-on treatment for resistant adenomas (18). In a previous metanalysis, cabergoline in monotherapy resulted less effective than SRLs, achieving tumor shrinkage in about one third of the enrolled patients (31). It should also be mentioned that some studies reported an escape phenomenon from its treatment efficacy (32).

Data coming from the combination of PAS LAR and pegvisomant in acromegaly were not considered in our metanalysis, due to inclusion criteria and variable combination therapy of the two drugs (33). Since some cases of adenoma growth had been reported during pegvisomant use (3435), this combination therapy represents a rational approach, but tumor volume analysis is less reliable, given the purpose of our study. Despite concerns regarding tumor growth, pegvisomant effectiveness in acromegaly is well documented (1829), although the cost of this combination treatment can limit its applicability in real-life practice. Moreover, it is worth mentioning Coopmans and collaborators’ follow-up analysis, suggesting a PAS mediated anti-tumoral effect in acromegaly. During treatment, patients exhibited a significant increase in T2-weighted sequences signal at MRI; moreover, patients exhibiting this MRI characteristic in their adenomas showed a more evident decrease in IGF-1 levels, but not a similar pattern in reduction of pituitary adenoma size (36). This finding may be related to cell degeneration or tumor cell necrosis, without necessarily determining significant tumor size reduction. Further studies, probably with more data coming from histological reports, may be necessary to better understand these findings.

Cushing’s Disease

Overall, PAS treatment provided significant tumor shrinkage in 41.2% of CD patients. Regarding pituitary-directed drugs, at this moment available for CD treatment, the efficacy of cabergoline has been proven in vitro studies, but its efficacy in clinical trials is still debated (1537). In a previous prospective study, cabergoline induced significant tumor shrinkage (defined as tumor volume reduction >20%) in 4 out of 20 (20%) of the patients recruited after 24 months (38). PAS is the only pituitary-directed treatment for this condition approved by Drug Agencies. Although few studies have been considered in this metanalysis, due to the strict inclusion criteria, PAS appears more effective in tumor size reduction versus cabergoline, resulting in a better choice in CD therapy when aiming to control the pituitary adenoma.

In contrast to acromegaly, the majority of CD patients present a microadenoma, suggesting that tumor size might be a less relevant issue during medical treatment, even if the “cure” of the disease may forecast the resolution of the adenoma. Besides, up to 30% of CD patients, depending also on MRI accuracy and neuro-radiologist’s expertise, may present with negative imaging that prevents any evaluation of tumor shrinkage (39). In spite of that, endocrinologists, not so infrequently, deal with aggressive corticotroph adenomas, characterized by invasive local growth and/or resistance to conventional therapies. This challenging entity often requires multidisciplinary expertise to suggest different approaches, including PAS treatment (40). It should be mentioned that some non-pituitary targeting drugs, as inhibitors of cortisol synthesis, have been associated with tumor growth, due to cortisol-ACTH negative feedback. In particular, during osilodrostat treatment in a phase III study, four recruited patients discontinued osilodrostat after a significant increase in tumor volume (two with micro- and two with macro-adenomas 41), and this growth had also been described during ketoconazole and mitotane treatments (42). Thus, it may be speculated that PAS could provide a rational approach as an combination treatment with steroidogenesis inhibitors. Moreover, after bilateral adrenalectomy, pituitary adenoma tumor size is of the utmost importance, as patients may be at risk of developing a progression of the adenoma, the so-called Nelson’s syndrome. In a prospective study from Daniel E et al., PAS proved to be also effective in this setting, reducing ACTH levels and stabilizing the residual tumor over a treatment period of 7 months (43). Further studies, with longer treatment observation, may reveal whether PAS may achieve significant tumor shrinkage in these patients, as suggested by previous case reports in literature (4445).

Conclusion

The main limitation of our study resides in the scarce literature provided up to now (260 patients with acromegaly and 34 with CD), in the different therapy schedules and different criteria for tumor shrinkage in the selected study (largest tumor diameter vs a selected percentage of reduction). Moreover, in none of the study tumor reduction was one of the primary endpoints, and surgery was performed before PAS in most patients (78-88% of CD and 43-96% of acromegaly).

PAS is a novel compound, with a rising role in the treatment of secreting pituitary adenomas. Thus, this topic might be amplified with more data coming from further clinical studies, as real-life studies, possibly also addressing markers predictive of response to this treatment (e.g., expression of SSR type 2 and type 5 or somatic mutations in USP8 at tissue level of ACTH-secreting adenomas). Nevertheless, we can already state that PAS treatment is effective in reducing tumor size, especially in acromegaly. Our results strengthen the role of PAS treatment in somatotroph and corticotroph adenomas, especially when tumor volume is a relevant issue (i.e. tumor progression, extrasellar invasion) (1839), as a neoadjuvant treatment before surgery or as tailored treatment, alone or in combination, in persistent disease or when surgery is not feasible. Future research aiming to characterize markers predictive of response could help to identify optimal candidates for this treatment.

Data Availability Statement

The original contributions presented in the study are included in the article. Further inquiries can be directed to the corresponding author.

Ethics Statement

Informed consent was obtained from all subjects participating in the studies analyzed.

Author Contributions

Authors involved contributed to research as reported: literature search (FC, AM), preparation of original draft (FC, AM, MB, LD), literature review (CS, FC, AM, MF), manuscript editing (CS, FC, AM, MB, LD, MF) and supervision (RM, CS). All authors approved the final version of the paper.

Conflict of Interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Publisher’s Note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

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Keywords: pasireotide, cushing, acromegaly, tumor volume, tumor size

Citation: Mondin A, Manara R, Voltan G, Tizianel I, Denaro L, Ferrari M, Barbot M, Scaroni C and Ceccato F (2022) Pasireotide-Induced Shrinkage in GH and ACTH Secreting Pituitary Adenoma: A Systematic Review and Meta-Analysis. Front. Endocrinol. 13:935759. doi: 10.3389/fendo.2022.935759

Received: 04 May 2022; Accepted: 06 June 2022;
Published: 01 July 2022.

Edited by:

Mohammad E. Khamseh, Iran University of Medical Sciences, Iran

Reviewed by:

Rosa Paragliola, Catholic University of the Sacred Heart, Rome, Italy
Marek Bolanowski, Wroclaw Medical University, Poland
Adriana G Ioachimescu, Emory University, United States

Copyright © 2022 Mondin, Manara, Voltan, Tizianel, Denaro, Ferrari, Barbot, Scaroni and Ceccato. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

*Correspondence: Filippo Ceccato, filippo.ceccato@unipd.it

ORCID: Alessandro Mondin, orcid.org/0000-0002-6046-5198
Renzo Manara, orcid.org/0000-0002-5130-3971
Giacomo Voltan, orcid.org/0000-0002-3628-0492
Irene Tizianel, orcid.org/0000-0003-4092-5107
Luca Denaro, orcid.org/0000-0002-2529-6149
Marco Ferrari, orcid.org/0000-0002-4023-0121
Mattia Barbot, orcid.org/0000-0002-1081-5727
Carla Scaroni, orcid.org/0000-0001-9396-3815
Filippo Ceccato, orcid.org/0000-0003-1456-8716

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

From https://www.frontiersin.org/articles/10.3389/fendo.2022.935759/full

Medications Used to Treat Cushing’s

Dr. Friedman uses several medications to treat Cushing’s syndrome that are summarized in this table. Dr. Friedman especially recommends ketoconazole. An in-depth article on ketoconazole can be found on goodhormonehealth.com.

 

 

 Drug How it works Dosing Side effects
Ketoconazole  (Generic, not FDA approved in US) blocks several steps in cortisol biosynthesis Start 200 mg at 8 and 10 PM, can up titrate to 1200 mg/day • Transient increase in LFTs
• Decreased testosterone levels
• Adrenal insufficiency
Levoketoconazole (Recorlev) L-isomer of Ketoconazole Start at 150 mg at 8 and 10 PM, can uptitrate up to 1200 mg nausea, vomiting, increased blood pressure, low potassium, fatigue, headache, abdominal pain, and unusual bleeding
Isturisa (osilodrostat) blocks 11-hydroxylase 2 mg at bedtime, then go up to 2 mg at 8 and 10 pm, can go up to 30 mg  Dr. Friedman often gives with spironolactone or ketoconazole. • high testosterone (extra facial hair, acne, hair loss, irregular periods)  • low potassium
• hypertension
Cabergoline (generic, not FDA approved) D2-receptor agonist 0.5 to 7 mg • nausea,  • headache  • dizziness
Korlym (Mifepristone) glucocorticoid receptor antagonist 300-1200 mg per day • cortisol insufficiency (fatigue, nausea, vomiting, arthralgias, and headache)
• increased mineralocorticoid effects (hypertension, hypokalemia, and edema
• antiprogesterone effects (endometrial thickening)
Pasireotide (Signafor) somatostatin receptor ligand 600 μg or 900 μg twice a day Diabetes, hyperglycemia, gallbladder issues

For more information or to schedule an appointment with Dr. Friedman, go to goodhormonehealth.com

The Cushings Disease Treatment Market To Be Consistent In The Next 10 Years

Cushing disease is caused by tumour in the pituitary gland which leads to excessive secretion of a hormone called adrenocorticotrophic (ACTH), which in turn leads to increasing levels of cortisol in the body. Cortisol is a steroid hormone released by the adrenal glands and helps the body to deal with injury or infection.

Increasing levels of cortisol increases the blood sugar and can even cause diabetes mellitus. However the disease is also caused due to excess production of hypothalamus corticotropin releasing hormone (CRH) which stimulates the synthesis of cortisol by the adrenal glands. The condition is named after Harvey Cushing, the doctor who first identified the disease in 1912. Cushing disease results in Cushing syndrome.

Cushing syndrome is a group of signs and symptoms developed due to prolonged exposure to cortisol. Signs and symptoms of Cushing syndrome includes hypertension, abdominal obesity, muscle weakness, headache, fragile skin, acne, thin arms and legs, red stretch marks on stomach, fluid retention or swelling, excess body and facial hair, weight gain, acne, buffalo hump, tiredness, fatigue, brittle bones, low back pain, moon shaped face etc. Symptoms vary from individual to individual depending upon the disease duration, age and gender of the patient.

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Disease diagnosis is done by measuring levels of cortisol in patient’s urine, saliva or blood. For confirming the diagnosis, a blood test for ACTH is performed. The first-line treatment of the disease is through surgical resection of ACTH-secreting pituitary adenoma, however disease management is also done through medications, Cushing disease treatment market comprises of the drugs designed for lowering the level of cortisol in the body. Thus patients suffering from Cushing disease are prescribed medications such as ketoconazole, mitotane, aminoglutethimide metyrapone, mifepristone, etomidate and pasireotide.

Cushing’s disease treatment market revenue is growing with a stable growth rate, this is attributed to increasing number of pipeline drugs. Also increasing interest of pharmaceutical companies to develop Cushing disease drugs is a major factor contributing to the revenue growth of Cushing disease treatment market over the forecast period.

Current and emerging players’ focuses on physician education and awareness regarding availability of different drugs for curing Cushing disease, thus increasing the referral speeds, time to diagnosis and volume of diagnosed Cushing disease individuals.

Growing healthcare expenditure and increasing awareness regarding Cushing syndrome aids in the revenue growth of Cushing’s disease treatment market. Increasing number of new product launches also drives the market for Cushing’s disease Treatment devices. However availability of alternative therapies for curing Cushing syndrome is expected to hamper the growth of the Cushing’s disease treatment market over the forecast period.

For entire list of market players, request for Table of content here @ https://www.persistencemarketresearch.com/toc/14155

The Cushing’s disease Treatment market is segment based on the product type, technology type and end user

Cushing’s disease Treatment market is segmented into following types:

By Drug Type
  • Ketoconazole
  • Mitotane
  • Aminoglutethimide
  • Metyrapone
  • Mifepristone
  • Etomidate
  • Pasireotide
By End User
  • Hospital Pharmacies
  • Retail Pharmacies
  • Drug Stores
  • Clinics
  • e-Commerce/Online Pharmacies

Cushing’s disease treatment market revenue is expected to grow at a good growth rate, over the forecast period. The market is anticipated to perform well in the near future due to increasing awareness regarding the condition. Also the market is anticipated to grow with a fastest CAGR over the forecast period, attributed to increasing investment in R&D and increasing number of new product launches which is estimated to drive the revenue growth of Cushing’s disease treatment market over the forecast period.

Depending on geographic region, the Cushing’s disease treatment market is segmented into five key regions: North America, Latin America, Europe, Asia Pacific (APAC) and Middle East & Africa (MEA).

North America is occupying the largest regional market share in the global Cushing’s disease treatment market owing to the presence of more number of market players, high awareness levels regarding Cushing syndrome. Healthcare expenditure and relatively larger number of R&D exercises pertaining to drug manufacturing and marketing activities in the region. Also Europe is expected to perform well in the near future due to increasing prevalence of the condition in the region.

Asia Pacific is expected to grow at the fastest CAGR because of increase in the number of people showing the symptoms of Cushing syndrome, thus boosting the market growth of Cushing’s disease treatment market throughout the forecast period.

Some players of Cushing’s disease Treatment market includes CORCEPT THERAPEUTICS, HRA Pharma, Strongbridge Biopharma plc, Novartis AG, etc. However there are numerous companies producing branded generics for Cushing disease. The companies in Cushing’s disease treatment market are increasingly engaged in strategic partnerships, collaborations and promotional activities to capture a greater pie of market share.

The research report presents a comprehensive assessment of the market and contains thoughtful insights, facts, historical data, and statistically supported and industry-validated market data. It also contains projections using a suitable set of assumptions and methodologies. The research report provides analysis and information according to categories such as market segments, geographies, types, technology and applications.

Cushing’s Disease—Monthly Injection Is Good Alternative to Surgery

Written by Kathleen Doheny with Maria Fleseriu, MD, FACE, and Vivien Herman-Bonert, MD

Cushing’s disease, an uncommon but hard to treat endocrine disorder, occurs when a tumor on the pituitary gland, called an adenoma—that is almost always benign—leads to an overproduction of ACTH (adrenocorticotropic hormone), which is responsible for stimulating the release of cortisol, also known as the stress hormone.

Until now, surgery to remove the non-cancerous but problematic tumor has been the only effective treatment. Still, many patients will require medication to help control their serum cortisol levels, and others cannot have surgery or would prefer to avoid it.

Finally, a drug proves effective as added on or alternative to surgery in managing Cushing’s disease. Photo; 123rf

New Drug Offers Alternative to Surgery for Cushing’s Disease

Now, there is good news about long-term positive results achieved with pasireotide (Signifor)—the first medication to demonstrate effectiveness in both normalizing serum cortisol levels and either shrinking or slowing growth of tumors over the long term.1,2  These findings appear in the journal, Clinical Endocrinology, showing that patients followed for 36 months as part of an ongoing study had improved patient outcomes for Cushing’s disease.2

“What we knew before this extension study was—the drug will work in approximately half of the patients with mild Cushing’s disease,” says study author Maria Fleseriu, MD, FACE, director of the Northwest Pituitary Center and professor of neurological surgery and medicine in the division of endocrinology, diabetes and clinical nutrition at the Oregon Health and Sciences University School of Medicine.

“Pasireotide also offers good clinical benefits,” says Dr. Fleseriu who is also the president of the Pituitary Society, “which includes improvements in blood pressure, other signs and symptoms of Cushing’s symptom], and quality of life.”2

What Symptoms Are Helped by Drug for Cushing’s Disease?  

Among the signs and symptoms of Cushing’s disease that are lessened with treatment are:3

  • Changes in physical appearance such as wide, purple stretch marks on the skin (eg, chest, armpits, abdomen, thighs)
  • Rapid and unexplained weight gain
  • A more full, rounder face
  • Protruding abdomen from fat deposits
  • Increased fat deposits around the neck area

The accumulation of adipose tissue raises the risk of heart disease, which adds to the urgency of effective treatment. In addition, many individuals who have Cushing’s disease also complain of quality of life issues such as fatigue, depression, mood and behavioral problems, as well as poor memory.2

As good as the results appear following the longer term use of pasireotide,2 Dr. Fleseriu admits that in any extension study in which patients are asked to continue on, there are some built-in limitations, which may influence the findings. For example, patients who agree to stay on do so because they are good responders, meaning they feel better, so they’re happy to stick with the study.

“Fortunately, for the patients who have responded to pasireotide initially, this is a drug that can be  continued as there are no new safety signals with longer use,” Dr. Fleseriu tells EndocrineWeb, “and when the response at the start is good, very few patients will lose control of their urinary free cortisol over time. That’s a frequent marker used to monitor patient’s status. For those patients with large tumors, almost half of them had a significant shrinkage, and all the others had a stable tumor size.”

What Are the Reasons to Consider Drug Treatment to Manage Cushing’s Symptoms

The extension study ”was important because we didn’t have any long-term data regarding patient response to this once-a-month treatment to manage Cushing’s disease,” she says.

While selective surgical removal of the tumor is the preferred treatment choice, the success rate in patients varies, and Cushing’s symptoms persist in up to 35% of patients after surgery. In addition, recurrent rates (ie, return of disease) range from 13% to 66% after individuals experience different durations remaining in remission.1

Therefore, the availability of an effective, long-lasting drug will change the course of therapy for many patients with Cushing’s disease going forward. Not only will pasireotide benefit patients who have persistent and recurrent disease after undergoing surgery, but also this medication will be beneficial for those who are not candidates for surgery or just wish to avoid having this procedure, he said.

Examining the Safety and Tolerability of Pasireotide  

This long-acting therapy, pasireotide, which is given by injection, was approved in the US after reviewing results of a 12-month Phase 3 trial.1  In the initial study, participants had a confirmed pituitary cause of the Cushing’s disease. After that, the researchers added the optional 12-month open-label, extension study, and now patients can continue on in a separate long-term safety study.

Those eligible for the 12-month extension had to have mean urinary free cortisol not exceeding the upper limit of normal (166.5 nanomoles per 24 hour) and/or be considered by the investigator to be getting substantial clinical benefit from treatment with long-action pasireotide, and to demonstrate tolerability of pasireotide during the core study.1

Of the 150 in the initial trial, 81 participants, or 54% of the patients, entered the extension study. Of those, 39 completed the next phase, and most also enrolled in another long-term safety study—these results not yet available).2

During the core study, 1 participants were randomly assigned to 10 or 30 mg of the drug every 28 days, with doses based on effectiveness and tolerability. When they entered the extension, patients were given the same dose they received at month.1,2

Study Outcomes Offer Advantages in Cushing’s Disease

Of those who received 36 months of treatment with pasireotide, nearly three in four (72.2%) had controlled levels of urinary free cortisol at this time point.2 Equally good news for this drug was that tumors either shrank or did not grow. Of those individuals who started the trial with a measurable tumor (adenoma) as well as those with an adenoma at the two year mark (35 people), 85.7% of them experienced a reduction of 20% or more or less than a 20% change in tumor volume. No  macroadenomas present at the start of the study showed a change of more than 20% at either month 24 or 36.2

Improvements in blood pressure, body mass index (BMI) and waist circumference continued throughout the extension study.1  Those factors influence CVD risk, the leading cause of death in those with Cushing’s.4

As for adverse events, most of the study participants, 91.4%, did report one or more complaint during the extension study—most commonly, it was high blood sugar, which was reported by nearly 40% of participants.2. This is not surprising when you consider that most (81.5%) of the individuals participating in the extension trial entered with a diagnosis of diabetes or use of antidiabetic medication, and even more of them (88.9%) had diabetes at the last evaluation.1  

This complication indicates the need for people with Cushing’s disease to check their blood glucose, as appropriate.

Do You Have Cushing’s Disese [sic]? Here’s What You Need to Know 

Women typically develop Cushing’s disease more often than men.

What else should you be aware of if you and your doctor decide this medication will help you? Monitoring is crucial, says Dr. Fleseriu, as you will need to have your cortisol levels checked, and you should be on alert for any diabetes signals, which will require close monitoring and regular follow-up for disease management.

Another understanding gained from the results of this drug study: “This medication works on the tumor level,” she says. “If the patient has a macroadenoma (large tumor), this would be the preferred treatment.” However, it should be used with caution in those with diabetes given the increased risk of experiencing high blood sugar.

The researchers conclude that “the long-term safety profile of pasireotide was very favorable and consistent with that reported during the first 12 months of treatment. These data support the use of long-acting pasireotide as an effective long-term treatment option for some patients with Cushing’s Disease.”1

Understanding Benefits of New Drug to Treat Cushing’s Diseease [sic]

Vivien S. Herman-Bonert, MD, an endocrinologist and clinical director of the Pituitary Center at Cedars-Sinai Medical Center in Los Angeles, agreed to discuss the study findings, after agreeing to review the research for EndocrineWeb.

As to who might benefit most from monthly pasireotide injections? Dr. Herman-Bonert says, “any patient with Cushing’s disease that requires long-term medical therapy, which includes patients with persistent or recurrent disease after surgery.” Certainly, anyone who has had poor response to any other medical therapies for Cushing’s disease either because they didn’t work well enough or because the side effects were too much, will likely benefit a well, she adds.

Among the pluses that came out of the study, she says, is that nearly half of the patients had controlled average urinary free cortisol levels after two full years, and 72% of the participants who continued on with the drug for 36 months were able to remain in good urinary cortisol control .1

As the authors stated, tumor shrinkage was another clear benefit of taking long-term pasireotide. That makes the drug a potentially good choice for those even with large tumors or with progressive tumor growth, she says. It’s always good for anyone with Cushing’s disease to have an alterative [sic] to surgery, or a back-up option when surgery isn’t quite enough, says Dr. Herman-Bonert.

The best news for patients is that quality of life scores improved,she adds.

Dr Herman-Bonert did add a note of caution: Although the treatment in this study is described as ”long-term, patients will need to be on this for far longer than 2 to 3 years,” she says. So, the data reported in this study may or may not persist, and we don’t yet know what the impact will be 10 or 25 years out.

Also, the issue of hyperglycemia-related adverse events raises a concern, given the vast majority (81%) of patients who have both Cushing’s disease and diabetes. Most of those taking this drug had a dual diagnosis—having diabetes, a history of diabetes, or taking antidiabetic medicine.

If you are under care for diabetes and you require treatment for Cushing’s disease, you must be ver mindful that taking pasireotide will likely lead to high blood sugar spikes, so you should plan to address this with your healthcare provider.

 

Dr. Fleseriu reports research support paid to Oregon Health & Science University from Novartis and other 0companies and consultancy fees from Novartis and Strongbridge Biopharma. Dr. Herman-Bonert has no relevant disclosures.

The study was underwritten by Novartis Pharma AG, the drug maker. 

From https://www.endocrineweb.com/news/pituitary-disorders/62449-cushings-disease-monthly-injection-good-alternative-surgery

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