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

Posted on November 21, 2018 by MaryO

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 BRAF, USP8, 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/

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

Posted on November 10, 2018 by MaryO

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/

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Rare Case of Cushing’s Disease Diagnosed in 7-year-old Boy

Posted on October 26, 2018 by MaryO

A recent case report describes a 7-year-old boy with Cushing’s disease who had an unusual clinical presentation, which significantly delayed his diagnosis.

The study, “A variable course of Cushing’s disease in a 7 year old: diagnostic dilemma,” was published in the Journal of Pediatric Endocrinology and Metabolism.

Rare in children and adolescents, Cushing’s disease refers to overproduction of cortisol caused by excessive adrenocorticotropic hormone (ACTH) secretion from a pituitary tumor. In pediatrics, early symptoms of excess cortisol include weight gain and delayed growth.

Despite being extremely unlikely in children younger than 7, some cases of Cushing’s disease in infancy have been reported.

“If undiagnosed or untreated it can lead to considerable morbidity and mortality, and the inability to detect a microadenoma [tumors smaller than 10 mm in diameter] on magnetic resonance imaging (MRI) can lead to a diagnostic dilemma leading to unnecessary delays in treatment initiation,” the researchers wrote.

Researchers from the Indraprastha Apollo Hospital in New Delhi, India, described a 7-year-old boy who complained of excessive appetite and weight gain in the previous five months. The child weighed 46.8 kg, was 127 cm tall, and had a body mass index (BMI) of 29, indicating he was overweight.

The child’s excess fat was mainly in his abdomen plus he had a round, red, puffy face, which are both common features of Cushing’s disease. He had no history of acute or chronic steroid intake, mood swings, sleep disorders, or issues with eyesight.

Given his clinical presentation, the investigators suspected the boy had Cushing’s disease or pseudo-Cushing’s disease, which refers to situations where the overproduction of cortisol is caused by something unrelated to the disease, such as stress or uncontrolled diabetes mellitus.

Biochemical testing showed the patient had high levels of cortisol, which remained unchanged after a dexamethasone suppression test. In addition, his levels of “bad” cholesterol, referring to low-density lipoprotein, were extremely elevated at 194 mg/dL, where a normal range is defined as less than 110 mg/dL.

Imaging revealed no lesions in the pituitary gland.

The boy was sent home with dietary recommendations. Eight weeks later, he had lost 4 kg, while his height remained the same; he also complained of headaches and various episodes of double vision.

This confused the clinical team as hallmarks of Cushing’s disease include short stature and weight loss triggered by pharmacological therapy. Despite having lost weight, he did not take any medications to help him with it, plus the boy’s height was normal for his age.

Nonetheless, the patient was complaining of neurological symptoms, suggesting progression of Cushing’s disease.

An ophthalmologist did not observe anything abnormal with the child’s eyes that could explain his double vision episodes.

A new series of tests revealed slightly elevated 24-hour urinary cortisol levels, decreased concentration of ACTH, and mildly increased cortisol levels after a two-day dexamethasone suppression test.

Magnetic resonance imaging (MRI) showed a small microadenoma in the right lobe of the pituitary gland.

Using Gamma Knife radiation therapy, a kind of high-precision radiation therapy, and surgery, doctors successfully removed the boy’s microadenoma. Six weeks post-procedure, his cortisol and ACTH concentrations returned to normal.

“MRI findings of the pituitary may be inconclusive in the beginning of the disease process and should be borne in mind during further follow-up. In cases where a clear-cut diagnosis may be difficult, a diligent follow-up is required to ascertain the course of the disease and to make timely diagnosis,” the investigators concluded.

From https://cushingsdiseasenews.com/2018/10/25/rare-case-cushings-disease-diagnosed-7-year-old-boy-case-study/

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Cushing’s Disease Patients with USP8 Mutations More Likely to Achieve Remission After Surgery

Posted on October 24, 2018 by MaryO

Cushing’s disease patients whose pituitary tumors carry a USP8 mutation are more likely to achieve remission after surgery than those without such mutations, a retrospective Italian study found.

The study, “Clinical characteristics and surgical outcome in USP8-mutated human adrenocorticotropic hormone-secreting pituitary adenomas,” was published in the journal Endocrine.

Cushing’s disease is a condition where a tumor on the pituitary gland produces too much of the adrenocorticotropin hormone (ACTH), which will act on the adrenal gland to make cortisol in excess.

While rare, the condition can be life-threatening, as excess cortisol is linked to an increased risk of infections and cardiovascular complications, along with an increased likelihood of obesity and diabetes.

The reasons some patients develop these pituitary adenomas are far from understood, but researchers recently found that some of these patients show mutations in the USP8 gene. These appear to increase EGFR signaling which, in turn, has a stimulatory role for the synthesis of ACTH.

But more than influencing the development of Cushing’s disease, researchers believe the USP8 mutations may also determine response to treatment.

Thus, a team in Italy examined whether patients with USP8 mutations presented different clinical features and responded differently to the standard surgical procedure, called transsphenoidal pituitary surgery.

The study included 92 patients with ACTH-secreting pituitary tumors who received surgery at the neurosurgical department of the Istituto Scientifico San Raffaele in Milan between 1996 and 2016.

“All surgical procedures were performed by the same experienced neurosurgeon, which is one of the most important factors affecting early and late surgical outcome of pituitary adenomas,” researchers explained.

Among study participants, 22 (23.9%) had mutations in the USP8 gene, but these mutations were significantly more common in women than in men — 28.7% vs. 5.3%. Researchers think estrogens — a female sex hormone — may have a role in the development of mutated pituitary tumors.

Overall, the two groups had similar tumor size and aggressiveness and similar ACTH and cortisol levels before surgery. But among those with microadenomas — tumors smaller then 10 mm in diameter — USP8-mutated patients had significantly larger tumor diameters.

After receiving surgery, 81.5% of patients achieved surgical remission — deemed as low cortisol levels requiring glucocorticoid replacement therapy, normal cortisol levels in urine, and normal response to a dexamethasone-suppression test.

But remission rates were significantly higher among those with USP8 mutations — 100% vs. 75.7%. Also, USP8 mutation carriers required steroid replacement therapy for shorter periods, despite ACTH and cortisol levels being similar among the two groups after surgery.

Among patients who entered remission, 12 (16%) saw their disease return. While more patients with USP8 mutations experienced a recurrence — 22.7% vs. 13.2% — this difference was not significant. After five years, 73.8% of UPS8-mutated patients remained alive and recurrence-free, which researchers consider comparable to the 88.5% seen in patients without the mutation.

Researchers also tested sex, age at surgery, and post-surgical ACTH and cortisol levels as possible predictors of disease recurrence, but none of these factors was associated with this outcome.

“ACTH-secreting pituitary adenomas carrying somatic USP8 mutations are associated with a greater likelihood of surgical remission in patients operated on by a single neurosurgeon. Recurrence rates are not related with USP8-variant status,” researchers concluded.

From https://cushingsdiseasenews.com/2018/10/23/cushings-disease-patients-usp8-mutations-more-likely-achieve-remission-after-surgery/

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Pregnancy Could Be Linked to Onset of Cushing’s Symptoms

Posted on October 2, 2018 by MaryO

More than 25 percent of women with Cushing’s disease experienced their first symptoms within one year of giving birth, a small study by the Pacific Neuroscience Institute found.

The findings suggest a possible causal relationship between the biological stress of pregnancy and Cushing’s disease (CD), with more than a two-fold risk of women developing the disease within one year of pregnancy.

The study, “Pregnancy-associated Cushing’s disease? An exploratory retrospective study,” was published in the journal Pituitary.

Eighty percent of Cushing’s disease cases are women, and most are of reproductive age.

Levels of the body’s main stress hormone, cortisol, normally increase during pregnancy. In the last weeks before birth, cortisol levels are two to three times higher than normal, similar to Cushing’s disease.

Because cortisol levels gradually increase during pregnancy, a diagnosis of Cushing’s disease within the gestation period is problematic.

Circumstantial “evidence suggests a higher incidence of CD immediately following pregnancy, in the peripartum period [a few weeks after childbirth],” the study’s authors wrote.

To shed additional light on the matter, researchers retrospectively investigated the frequency of Cushing’s disease onset related to pregnancy.

A total of 64 women with biochemically-diagnosed Cushing’s disease and treated at Providence Saint John’s Health Center in Santa Monica, California, from July 2007 to December 2017 were included in this study.

For the analysis, patients were divided into three groups:

  1. Women with pregnancy-associated CD: “defined as symptom-onset within 1 year of pregnancy that was explicitly linked to the pregnancy by the patient’s own recollection of her pregnancy and subsequent symptoms related to CD”;
  2. Women of reproductive age: “defined as age 15–45 years, in whom CD onset was not associated temporally with pregnancy within the past year”;
  3. Women not of reproductive age at the time of CD onset.

Results showed that 64 percent of the patients were of childbearing age at the time of diagnosis. Of these, 27 percent (11 women) had pregnancy-associated Cushing’s disease. This might be due to small, slow-growing or dormant corticotroph pituitary adenomas that were stimulated by pregnancy-related hormonal changes; however, this hypothesis was not confirmed by the researchers.

On average, patients in group 1 had two pregnancies prior to Cushing’s disease onset, compared to zero for 30 other women with disease onset during reproductive age. This suggests that undergoing the biological stress of pregnancy more than once could play a role in Cushing’s development.

“Another possible explanation of the association between CD and pregnancy is simply that patients are more likely to remember the onset of their CD symptoms in relation to a landmark life event such as pregnancy and childbirth, which leads to long-term physical changes in most women, irrespective of Cushing’s status,” the researchers noted.

In contrast, 19 of the 30 patients at reproductive age without pregnancy-associated disease had no pregnancies before being diagnosed, which weakens the association between pregnancy and Cushing’s and draws attention to various other factors that may also be involved in disease onset, apart from gestation-related hormonal changes.

The time from the onset of symptoms to diagnosis for women with pregnancy-related disease varied from two to six years.

“It was in fact weight gain or failure to lose weight post-pregnancy, which was the most frequent complaint and presentation in our patients with pregnancy-associated CD, and which often lead to an eventual diagnosis of CD,” the researchers stated.

“As such, appropriate biochemical testing may be indicated in women who 6–18 months after pregnancy, are still unable to lose the weight of pregnancy, continue to gain weight, have new, persistent or more [treatment-resistant] hypertension and diabetes mellitus, and/or other classical stigmata of CD,” they suggested.

All patients with biochemically-confirmed Cushing’s disease underwent surgery to remove pituitary adenoma. Sustained surgical remission rates for groups 1, 2, and 3 were 91%, 80%, and 83%, respectively.

“This possible association suggests a heightened degree of clinical suspicion and biochemical testing for CD may be warranted after childbirth. Further study of this possible link between pregnancy and CD is warranted,” the team concluded.

From https://cushingsdiseasenews.com/2018/09/21/cushings-disease-symptoms-onset-pregnancy-could-be-linked-study-suggests/

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