Mutations in Two Genes, USP48 and BRAF, Linked to Cushing’s Disease

Mutations in USP48 and BRAF genes contribute to the overproduction of adrenocorticotropin (ACTH) hormone by the pituitary gland and consequent development of Cushing’s disease, a study shows, linking these genes to the disease for a first time.

The study, “Identification of recurrent USP48 and BRAF mutations in Cushing’s disease,” published in the journal Nature Communications, also identified a possible treatment for patients with BRAF-related mutations.

Cushing’s disease is a condition characterized by excessive cortisol levels that, if left untreated, can lead to serious cardiovascular problems, infections, and mood disorders. It usually arises from benign pituitary tumors that produce too much of ACTH hormone, which in turn stimulates the adrenal glands to secrete cortisol.

It is still not clear why some people develop these tumors, but studies have pointed to mutations in the USP8 gene as a possible cause. They are present in 35%–62% of all tumor cases, and influence treatment response and long-term outcomes.

But major disease drivers in people whose tumors have no evidence of  USP8 mutations are unknown. Recognizing this gap, researchers in China examined tumor tissue samples from 22 patients with pituitary ademonas but a normal USP8 gene.

Their analysis revealed four genes that were recurrently mutated, including two — BRAF and USP48 — never before reported in this disease setting. Then, looking at 91 samples from patients, researchers found BRAF mutations in 17% of cases and USP48 mutations in 23% of patients.

These mutations were also found in patients with USP8-mutant pituitary tumors, but at a much lower rate — 5.1% for BRAF and 1.2% for USP48 mutations.

However, mutations in these two genes were not seen in patients with pituitary tumors producing other hormones, suggesting they are “unique genetic signatures of [ACTH-producing] adenomas,” the researchers wrote.

The team also found that BRAF and USP48 mutations activate signaling pathways that lead to the production of proopiomelanocortin (POMC), which is the precursor of ACTH.

“ACTH overproduction is a hallmark of Cushing’s disease and appears to be frequently induced by mutations in genes that tightly regulate POMC gene transcription in the pathogenesis of this disease,” investigators wrote.

Patients with BRAF and USP48 mutations had significantly higher levels of midnight plasma ACTH and midnight serum cortisol, compared to patients without these mutations. Tumor size, however, was similar among the two groups.

Interestingly, the team found that the BRAF inhibitor Zelboraf (vemurafenib) effectively reduced ACTH production in cells from ACTH-producing pituitary tumors. Zelboraf, marketed by Genentech, is approved in the U.S. and Europe to treat cancers with BRAF mutations, and findings suggest it may be a good therapeutic candidate for some people with Cushing’s disease.

“The mutational status of BRAFUSP8, and USP48 in corticotroph adenomas may be used in the future to characterize the molecular subtypes and guide targeted molecular therapy,” the researchers suggested.

From https://cushingsdiseasenews.com/2018/11/20/mutations-in-usp48-braf-genes-contribute-for-cushings-disease-study-finds/

Pituitary Tumors Affect Patients’ Ability to Work, Reduce Quality of Life

Pituitary tumor conditions, such as Cushing’s disease, have a substantial effect on patients’ work capabilities and health-related quality of life, researchers from The Netherlands reported.

The study, “Work disability and its determinants in patients with pituitary tumor-related disease,” was published in the journal Pituitary.

Pituitary tumors, like those that cause Cushing’s disease, have significant effects on a patient’s physical, mental, and social health, all of which influence their work status and health-related quality of life. However, the effects of the disease on work status is relatively under-investigated, investigators report.

Here, researchers evaluated the work disability among patients who were treated for pituitary tumors in an attempt to understand the impact of disease diagnosis and treatment on their social participation and ability to maintain a paying job.

In their study, researchers examined 241 patients (61% women) with a median age of 53 years. The majority (27%) had non-functioning pituitary tumors, which do not produce excess hormones, but patients with acromegaly, Cushing’s disease, prolactinomas, and Rathke’s cleft cyst also were included.

Participants were asked to complete questionnaires to evaluate their health-related quality of life and disease-specific impact on their work capabilities. Each participant completed a set of five questionnaires.

Participants also reported their hormonal status and demographic data, including gender, age, education, and marital status. Specific information, such as disease diagnosis, treatment, and tumor type was obtained from their medical records.

Work status and productivity were assessed using two surveys, the Short-Form-Health and Labour Questionnaire (SF-HLQ) and the work role functioning questionnaire 2.0 (WRFQ).

SF-HLQ was used to obtain information on the participants’ employment and their work attendance. Employment was either paid or unpaid. (Participation in household chores was considered not having a paid job.)

WRFQ is a 27-question survey that determines work disability regarding being able to meet the productivity, physical, emotional, social, and flexible demands. A higher score indicates low self-perceived work disability.

Disease-specific mood problems, social and sexual functioning issues, negative perceptions due to illness, physical and cognitive difficulties, were assessed using a 26-item survey called Leiden Bother and Needs for Support Questionnaire for pituitary patients(LBNQ-Pituitary).

Overall, 28% of patients did not have a paid job, but the rates increased to 47% among those with Cushing’s disease. Low education, hormonal deficits, and being single were identified as the most common determinants of not having a paid job among this population.

Further analysis revealed that more patients with Cushing’s disease and acromegaly had undergone radiotherapy. They also had more hormonal deficits than others with different tumor types.

Overall, patients with a paid job reported working a median of 36 hours in one week and 41% of those patients missed work an average of 27 days during the previous year. Health-related problems during work also were reported by 39% with a paid job.

Finally, health-related quality of life was determined using two questionnaires: SF-36 and EQ-5D. The physical, mental, and emotional well being was measured with SF-36, while ED-5D measured the health outcome based on the impact of pain, mobility, self-care, usual activities, discomfort, and anxiety or depression. In both SF-36 and EQ-5D, a higher score indicates a better health status.

Statistical analysis revealed that the quality of life was significantly higher in patients with a job. Overall, patients with a paid job reported better health status and higher quality of life than those without a paid job.

Although 40% of the patients reported being bothered by health-related problems in the past year, only 12% sought the help of an occupational physician, the researchers reported.

“Work disability among patients with a pituitary tumor is substantial,” investigators said.

“The determinants and difficulties at work found in this study could potentially be used for further research, and we advise healthcare professionals to take these results into consideration in the clinical guidance of patients,” they concluded.

From https://cushingsdiseasenews.com/

FDA Approves High-resolution MRI, Better at Spotting Pituitary Tumors in Cushing’s Patients

The U.S. Food and Drug Administration has approved the clinical use of a magnetic resonance imaging (MRI) scanner — the ultra-high-field 7T Terra MRI — with unprecedented resolution that allows for more reliable images of the brain.

The approach recently allowed the precise localization of a small tumor in the pituitary gland, which standard MRI had failed to spot, in a patient with Cushing’s disease.

So far, only one scanner of this kind exists in the U.S.. It was installed in February 2017 at the Mark and Mary Stevens Neuroimaging and Informatics Institute (INI) of the Keck School of Medicine, University of Southern California (USC).

The new scanner has an increased magnetic field strength of 7 Tesla, which is more than four times that of conventional MRI. This property greatly improves the instrument’s signal-to-noise ratio, dramatically increasing the spatial resolution and contrast of its images so that scientists can visualize the human living brain in high-definition and with unprecedented detail.

The 7T Terra is ideal for high-resolution neuroimaging, exploration of neurodegenerative diseases such as Alzheimer’s and Parkinson’s, and diagnosis and treatment of other brain diseases, a USC news story by Zara Greenbaum states.

Earlier this year, a report described the case of women with Cushing’s disease with a pituitary adenoma (slow-growing, benign tumor in the pituitary gland) that was possible to localize only with the new 7T MRI.

Based on laboratory analysis that revealed high levels of adrenocorticotropic hormone(ACTH) and cortisol, the doctors suspected a pituitary adenoma and recommended the patient for surgery. However, they ignored the precise location of the tumor, which failed to be detected by standard MRI scanners (1T and 3T).

    Two hours before surgery, the woman underwent a 7T MRI scan which finally identified with high precision the location of the adenoma, a very small tumor of 8 mm on the right side of the pituitary gland.

    “The 7T may save patients an invasive procedure. It also makes it easier for neurosurgeons to selectively remove a tumor without damaging surrounding areas,” said Gabriel Zada, MD, associate professor of neurological surgery at the Keck School.

    Since its arrival, the device has supported exploratory research into both healthy and diseased brains.

    Now the scanner’s advanced imaging technology can be used to help with diagnosis, treatment and monitoring of patients with neurological diseases, including Cushing’s disease.

    “This device, which has already made its mark as a powerful tool to advance research in the neurosciences, is now accessible to clinical populations in addition to researchers,” said Arthur W. Toga, PhD, provost professor and chair at the Keck School and director of the USC Stevens INI.

    “Clinicians across the university and beyond can now leverage all the benefits of increased spatial resolution to serve patients in need,” he said.

    Adapted from https://cushingsdiseasenews.com/2018/11/06/fda-oks-high-resolution-mri-better-spotting-pituitary-tumor-cushings/

    Stress, cortisol and weight gain

    If you’ve got your finger on the pulse of health trends, it’s likely you’ve been hearing the current buzzwords “cortisol creates belly fat” and “cortisol causes muscle wasting and fat storage.” These are the type of catch phrases that gain momentum every few years. And although some of the fads and trends showing up seasonally in fitness are myths, this caution about chronically elevated cortisol is true. Cortisol is also deeply connected with the dangers of chronic inflammation, which I described in another article, “Inflammation Creates Diseases.”

    Like many hormones, cortisol has an effect on a wide variety of functions in the body. Although it’s getting particularly demonized lately, cortisol serves some very important and positive functions in the body. It’s an essential component of the flight or flight response, so it gives us energy, focus, strength, motivation and courage. But, like with sugar or caffeine, it comes with a crash that feels like an emotional, psychological and physical drain. Cortisol is important for survival, but we didn’t evolve to have high levels of it all the time.

    According to hormone.org, cortisol isn’t only a stress hormone: “Because most bodily cells have cortisol receptors, it affects many different functions in the body. Cortisol can help control blood sugar levels, regulate metabolism, help reduce inflammation and assist with memory formulation. It has a controlling effect on salt and water balance and helps control blood pressure. In women, cortisol also supports the developing fetus during pregnancy. All of these functions make cortisol a crucial hormone to protect overall health and well-being.”

    There are many symptoms of chronically elevated cortisol levels. With that said, the way a spike of cortisol gives you a jolt of energy is by raising blood sugar. It does this by way of gluconeogenesis. This literally means “creating new sugar,” and it happens by way of breaking protein down into amino acids that are then turned into sugar by the liver. What is a large source of protein in the body? Yep, muscles. This is what is meant by “cortisol causes muscle loss.” This in turn contributes to muscle weakness. Whereas normal levels of cortisol help to regulate blood sugar levels by breaking down only a little muscle (which can be replaced with exercise), excessive levels cause muscle wasting.

    Why does cortisol cause fat gain? Remember those cortisol receptors most cells have? Fat cells have four times as many, so they are particularly responsive to cortisol. Okay, remember all that glucose the cortisol surge dumped into your blood for energy? Well, that also came with an insulin response to get your blood sugar levels back down, and insulin causes energy storage. And where do you store the energy? Yep, in those hypersensitive fat cells that cortisol just turned on. And what happens when you have too much insulin over time? Yep, diabetes. Also, another reason stress can cause emotional and/or binge eating is because cortisol also fires up your sense of purpose, as well as your appetite. So now stress has made you feel motivated…to eat.

    Emotionally and psychologically, chronically high cortisol can exacerbate depression, anxiety, irritability and lack of emotional control. Cortisol triggers a release of tryptophan oxygenase. This enzyme breaks down tryptophan. Tryptophan is required for creating serotonin. Serotonin gives us the ability to feel happiness, and it also affects appetite, sleep and sexual desire. Since extended exposure to high levels of cortisol inhibits the production of serotonin, all the symptoms of low serotonin become problematic (decreased appetite, insomnia, impotence, etc.). In short, prolonged stress causes depression.

    Cortisol also plays a role in the circulatory system. It manipulates blood pressure by acting as a diuretic. Excess cortisol causes an electrolyte imbalance, whereby sodium is retained, but potassium is excreted. Let me take you back to your high school biology days: Muscles fire because of the sodium potassium pump. The sodium potassium pump also effects the firing of nerves, including those impulses that cause your heart to beat and your kidneys to take in water for filtration. That sodium potassium pump is important throughout the entire body, across many of its biological functions. Because cortisol increases the concentration of sodium in your body, it has a direct impact on your blood pressure. Remember why excess salt can cause high blood pressure? Because it contains sodium. For all these reasons and more, chronically elevated cortisol also causes muscle weakness (ironic, since short bursts of it temporarily increase strength).

    Cortisol has other effects on minerals. According to the Hindawi Journal of Sports Medicine, “Cortisol triggers bone mineral resorption (removal) in order to free amino acids for use as an energy source through gluconeogenesis. Cortisol indirectly acts on bone by blocking calcium absorption, which decreases bone cell growth.” As you can see, excess cortisol causes osteoporosis. It also exacerbates other bone mineral density diseases, which means cortisol can leave you literally brittle with stress.

    Practically anything can become a stressor in the right conditions, and fight or flight is our only biological response to stress. Some triggers of stress include conflict, worry, alcohol and drug consumption, processed foods, excess exercise (especially prolonged and repeated sessions of low-level steady-state cardio training), sleep deprivation, thirst and hunger. As much as possible, protect yourself from stress with rest, relaxation, meditation, play time and healthy foods full of antioxidants, which reduce inflammation and thus the risks for practically all diseases.

    Jack Kirven completed the MFA in Dance at UCLA, and earned certification as a personal trainer through NASM. His wellness philosophy is founded upon integrated lifestyles as opposed to isolated workouts. Visit him at jackkirven.com and INTEGRE8Twellness.com.

    Adapted from https://goqnotes.com/61597/stress-cortisol-and-weight-gain/

    No Association Between Long-Term Gh Replacement, Comorbidities In Nonfunctioning Pituitary Adenoma

    Hammarstrand C, et al. Eur J Endocrinol. 2018;doi:10.1530/EJE-18-0370.

    Patients with growth hormone deficiency due to nonfunctioning pituitary adenoma experienced excessive morbidity due to cerebral infarction and sepsis regardless of whether they received long-term GH therapy, whereas treatment was associated with a normal incidence of type 2 diabetes, despite higher BMI and more severe hypopituitarism in treated patients, according to findings from an observational, registry-based study.

    “Although growth hormone replacement therapy is well-established and reverses most of the features associated with GH [deficiency], one of the safety concerns is the reduction in insulin sensitivity and the potential risk of developing type 2 diabetes mellitus,” Daniel S. Olsson, MSc, MD, PhD, professor at the Sahlgrenska Academy Institute of Medicine at the University of Gothenburg, Sweden, and colleagues wrote in the study background.

    Studies examining whether there is an association have produced mixed results, the researchers wrote, and it remains unknown to what extent GH deficiency — and GH therapy —contribute to the development of type 2 diabetes and other comorbidities, including cerebral infarction, malignant tumors, myocardial infarction or fractures.

    Olsson and colleagues analyzed data from 426 patients treated or followed for nonfunctioning pituitary adenoma between 1997 and 2011, selected from the Swedish National Patient Register. Researchers assessed information on tumor treatment, hormone therapy, antihypertensive medication, BMI and duration of GH therapy. For patients with type 2 diabetes, researchers assessed HbA1c values, insulin treatment, oral antidiabetes therapies and lipid-lowering therapies. Researchers followed the cohort through December 2014 or until death. Patients were stratified by use of GH therapy. Researchers calculated standardized incidence ratios (SIRs) based on the observed number of comorbidities among patients with nonfunctioning pituitary adenoma vs. the expected number of comorbidities in the background population.

    Within the cohort, 207 patients received GH therapy (145 men) and 219 did not (129 men). Median duration of GH therapy was 11.7 years; mean age at diagnosis was 56 years for treated patients and 65 years for untreated patients. Median follow-up time for treated and untreated patients was 12.2 years and 8.2 years, respectively.

    Incidence of cerebral infarction was increased for the whole cohort regardless of GH therapy status, with an SIR of 1.39 (95% CI, 1.03-1.84), and was most evident among 97 patients who underwent radiotherapy, in which 19 cerebral infarctions occurred vs. the expected number of 9.8 (P = .011).

    “The study showed an increased overall incidence of cerebral infarction in patients with [nonfunctioning pituitary adenoma] compared to the general population that was related to previous radiotherapy, but not to GH [replacement therapy],” the researchers wrote.

    Incidence of myocardial infarction was similar for treated and untreated patients, with SIRs of 1.18 (95% CI, 0.73-1.8) and 1.23 (95% CI, 0.82-1.78), respectively. Incidence of receiving medical treatment for hypertension was also similar between groups.

    In assessing incidence of type 2 diabetes, the researchers found that the SIR was higher among untreated patients (1.65; 95% CI, 1.06-2.46) vs. treated patients, who had an SIR similar to the background population (0.99; 95% CI, 0.55-1.63). Treated patients with type 2 diabetes had higher BMI vs. untreated patients with type 2 diabetes (P = .01), according to researchers, and glycemic status was similar among treated and untreated patients.

    The incidence of sepsis requiring hospitalization was also similar between treated and untreated patients, with rates for both groups close to double that of the background population (P < .001). Incidence of malignant tumors was not increased for treated or untreated patients when compared against the background population, according to the researchers. – by Regina Schaffer

    DisclosuresThe Gothenburg Growth Hormone Database is supported partly through unrestricted grants from Novo Nordisk, Pfizer and Sandoz. Olsson reports he has served as a consultant for Ipsen, Pfizer and Sandoz. Another author reports he has served as a consultant to AstraZeneca and Viropharma/Shire, and received lecture fees from Novo Nordisk, Otsuka and Pfizer.

    From https://www.healio.com/endocrinology/neuroendocrinology/news/in-the-journals/%7B0739a3a3-f592-4352-93f0-2ee5b5a89251%7D/no-association-between-long-term-gh-replacement-comorbidities-in-nonfunctioning-pituitary-adenoma

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