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Drivers of sporadic benign pituitary adenoma growth are largely unknown. Whole-exome sequencing of 159 prospectively resected pituitary adenomas showed that somatic copy number alteration (SCNA) rather than mutation is a hallmark of hormone-secreting adenomas and that SCNAs correlate with adenoma phenotype. Using single-gene SCNA pathway analysis, we observed that both cAMP and Fanconi anemia DNA damage repair pathways were affected by SCNAs in growth hormone-secreting (GH-secreting) somatotroph adenomas. As somatotroph differentiation and GH secretion are dependent on cAMP activation and we previously showed DNA damage, aneuploidy, and senescence in somatotroph adenomas, we studied links between cAMP signaling and DNA damage. Stimulation of cAMP in C57BL/6 mouse primary pituitary cultures using forskolin or a long-acting GH-releasing hormone (GHRH) analog increased GH production and DNA damage measured by H2AX phosphorylation and a comet assay. Octreotide, a somatostatin receptor ligand that targets somatotroph adenoma GH secretion in patients with acromegaly, inhibited cAMP and GH and reversed DNA damage induction. In vivo long- acting GHRH treatment also induced pituitary DNA damage in mice. We conclude that cAMP, which induces somatotroph proliferation and GH secretion, may concomitantly induce DNA damage, potentially linking hormone hypersecretion to SCNA and genome instability. These results elucidating somatotroph adenoma pathophysiology identify pathways for targeted treatment., Introduction Adenomas arising from the anterior pituitary are invariably benign and may either be nonhormone secreting (nonfunctioning) or hormone secreting (functioning) (1, 2). The prevalence of identified pituitary adenomas ranges [...]

The dramatic rise in opioid use over the last two decades has led to a surge in their harmful health effects. Lesser known among clinicians is the impact of opioids on the endocrine system, especially with regard to cortisol. Opioids can suppress the hypothalamus-pituitary-adrenal (HPA) axis and may result in clinically significant adrenal insufficiency, especially in those treated at higher doses and for a longer time. A high clinical suspicion is necessary in this population for early diagnosis of opioid-induced adrenal insufficiency (OAI). Diagnosis of OAI is challenging, as the symptoms are often vague and overlap with those due to opioid use or the underlying pain disorder. Traditional assays to diagnose adrenal insufficiency have not been widely studied in this population, and more investigation is needed to determine how opioids might affect assay results. Once a diagnosis of adrenal insufficiency has been made, glucocorticoid replacement in the form of hydrocortisone is likely the mainstay of treatment, and effort should be made to taper down opioids where possible. Cortisol levels should be retested periodically, with the goal of stopping glucocorticoid replacement once the HPA axis has recovered. In this review, we provide context for diagnostic challenges in OAI, suggest diagnostic tools for this population based on available data, and offer recommendations for the management of this disorder. There is a paucity of literature in this field; given the widespread use of opioids in the general population, more investigation into the effects of opioids on the HPA axis is sorely needed. [ABSTRACT FROM AUTHOR]

Context: Postoperative hyponatremia leads to prolonged hospital length of stay and readmission within 30 days. Objective: To assess 3 strategies for reducing rates of postoperative hyponatremia and analyze risk factors for hyponatremia. Design: Two retrospective analyses and 1 prospective study. Setting: Tertiary referral hospital. Patients: Patients undergoing transsphenoidal surgery for pituitary adenomas and other sellar and parasellar pathologies. Intervention(s): Phase 1: no intervention. Phase 2: postoperative day (POD) 7 sodium testing and patient education. Phase 3: fluid restriction to 1 L/day on discharge in addition to phase 2 interventions. Main outcome measures: Rates of early and delayed hyponatremia and readmissions. Secondary outcomes were risk factors for hyponatremia and readmission costs. Results: In phase 1, 296 patients underwent transsphenoidal surgery. Twenty percent developed early and 28% delayed hyponatremia. Thirtyeight percent underwent POD 7 sodium testing. Readmission rates were 15% overall and 4.3% for hyponatremia. In phase 2 (n=316), 22% developed early and 25% delayed hyponatremia. Eighty-nine percent complied with POD 7 sodium testing. Readmissions were unchanged although severity of hyponatremia was reduced by 60%. In phase 3 (n=110), delayed hyponatremia was reduced 2-fold [12.7%, relative risk (RR) =0.52] and readmissions 3-fold [4.6%, RR=0.30 (0.12–0.73)]; readmissions for hyponatremia were markedly reduced. Hyponatremia readmission increased costs by 30%. Conclusions: Restricting fluid to 1 L/day on discharge decreases rates of delayed hyponatremia and readmissions by 50%. Standardized patient education and POD 7 sodium testing decreases severity of hyponatremia but does not impact readmission rates. These protocols should be considered standard practice for patients undergoing transsphenoidal surgery. [ABSTRACT FROM AUTHOR]

Context: Preclinical studies show seliciclib (R-roscovitine) suppresses neoplastic corticotroph proliferation and pituitary adrenocorticotrophic hormone (ACTH) production. Objective: To evaluate seliciclib as an effective pituitary-targeting treatment for patients with Cushing disease (CD). Methods: Two prospective, open-label, phase 2 trials, conducted at a tertiary referral pituitary center, included adult patients with de novo, persistent, or recurrent CD who received oral seliciclib 400 mg twice daily for 4 consecutive days each week for 4 weeks. The primary endpoint in the proof-of-concept single-center study was normalization of 24-hour urinary free cortisol (UFC; =50 µg/24 hours) at study end; in the pilot multicenter study, primary endpoint was UFC normalization or = 50% reduction in UFC from baseline to study end. Results: Sixteen patients were consented and 9 were treated. Mean UFC decreased by 42%, from 226.4±140.3 µg/24 hours at baseline to 131.3± 114.3 µg/24 hours by study end. Longitudinal model showed significant UFC reductions from baseline to each treatment week. Three patients achieved = 50% UFC reduction (range, 55%-75%), and 2 patients exhibited 48% reduction; none achieved UFC normalization. Plasma ACTH decreased by 19% (P=0.01) in patients who achieved = 48% UFC reduction. Three patients developed grade = 2 elevated liver enzymes, anemia, and/or elevated creatinine, which resolved with dose interruption/reduction. Two patients developed grade 4 liverrelated serious adverse events that resolved within 4 weeks of seliciclib discontinuation. Conclusion: Seliciclib may directly target pituitary corticotrophs in CD and reverse hypercortisolism. Potential liver toxicity of seliciclib resolves with treatment withdrawal. The lowest effective dose requires further determination. [ABSTRACT FROM AUTHOR]

Cushing disease is a condition in which the pituitary gland releases excessive adrenocorticotropic hormone (ACTH) as a result of an adenoma arising from the ACTH-secreting cells in the anterior pituitary. ACTH-secreting pituitary adenomas lead to hypercortisolemia and cause significant morbidity and mortality. Pituitary-directed medications are mostly ineffective, and new treatment options are needed. As these tumors express EGFR, we tested whether EGFR might provide a therapeutic target for Cushing disease. Here, we show that in surgically resected human and canine corticotroph cultured tumors, blocking EGFR suppressed expression of proopiomelanocortin (POMC), the ACTH precursor. In mouse corticotroph EGFR transfectants, ACTH secretion was enhanced, and EGF increased Pomc promoter activity, an effect that was dependent on MAPK. Blocking EGFR activity with gefitinib, an EGFR tyrosine kinase inhibitor, attenuated Pomc expression, inhibited corticotroph tumor cell proliferation, and induced apoptosis. As predominantly nuclear EGFR expression was observed in canine and human corticotroph tumors, we preferentially targeted EGFR to mouse corticotroph cell nuclei, which resulted in higher Pomc expression and ACTH secretion, both of which were inhibited by gefitinib. In athymic nude mice, EGFR overexpression enhanced the growth of explanted ACTH-secreting tumors and further elevated serum corticosterone levels. Gefitinib treatment decreased both tumor size and corticosterone levels; it also reversed signs of hypercortisolemia, including elevated glucose levels and excess omental fat. These results indicate that inhibiting EGFR signaling may be a novel strategy for treating Cushing disease., Introduction Pituitary tumors, accounting for approximately 15% of intracranial tumors, are invariably benign monoclonal adenomas with excessive hormone secretion and/or tumor mass effects compressing vital structures (1). Adrenocorticotropic hormone-secreting (ACTH-secreting) [...]

As commonly encountered, pituitary adenomas are invariably benign. We therefore studied protective pituitary proliferative mechanisms. Pituitary tumor transforming gene (Pttg) deletion results in pituitary p21 induction and abrogates tumor development in [Rb.sup.+/-][Pttg.sup.-/-] mice. p21 disruption restores attenuated [Rb.sup.+/-][Pttg.sup.-/-] pituitary proliferation rates and enables high penetrance of pituitary, but not thyroid, tumor growth in triple mutant animals (88% of [Rb.sup.+/-] and 72% of [Rb.sup.+/-][Pttg.sup.-/-][p21.sup.-/-] vs. 30% of [Rb.sup.+/-][Pttg.sup.-/-] mice developed pituitary tumors, P < 0.001). p21 deletion also accelerated S-phase entry and enhanced transformation rates in triple mutant MEFs. Intranuclear p21 accumulates in Pttg-null aneuploid GH-secreting cells, and G[H.sub.3] rat pituitary tumor cells overexpressing PTTG also exhibited increased levels of mRNA for both p21 (18-fold, P < 0.01) and ATM (9-fold, P < 0.01). PTFG is abundantly expressed in human pituitary tumors, and in 23 of 26 GH-producing pituitary adenomas with high PTTG levels, senescence was evidenced by increased p21 and SA-[beta]-galactosidase. Thus, either deletion or overexpression of Pttg promotes pituitary cell aneuploidy and p53/p21-dependent senescence, particularly in GH-secreting cells. Aneuploid pituitary cell p21 may constrain pituitary tumor growth, thus accounting for the very low incidence of pituitary carcinomas. acromegaly | nonfunctioning adenoma | pituitary adenoma | PTFG

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ydbio.2008.03.039 Byline: Ning-Ai Liu (a), Meina Ren (a), Jianbo Song (b), Yesenia Rios (b), Kolja Wawrowsky (a), Anat Ben-Shlomo (a), Shuo Lin (b), Shlomo Melmed (a) Keywords: GFP; green fluorescent protein; POMC; pro-opiomelanocortin; MO; morpholino; FGF; fibroblast growth factors; RPD; rostral pars distalis; PPD; proximal pars distalis; PI; pars intermedia Abstract: The anterior pituitary gland (adenohypophysis) comprises anterior and intermediate lobes (the pars distalis and pars intermedia) arising from placodal ectoderm at the anterior neural ridge. Signaling molecules including SHH, FGF, WNT, BMP and Notch are involved in regulating primordial pituitary proliferation and lineage determination. However, morphogenic events and molecular mechanisms governing anterior and intermediate lobe specification are not clear. Pituitary expression of proopiomelanocortin (POMC), the common precursor for adrenocorticotropin (ACTH) of pars distalis corticotropes and [alpha]-melanocyte-stimulating hormone ([alpha]-MSH) of pars intermedia melanotropes, provides a unique marker for anterior and intermediate lobe morphogenesis. We performed time-lapse confocal microscopy lineage tracing in live zebrafish embryos expressing GFP driven by the pomc promoter and show distinct migration pathways of POMC cells destined to the anterior and intermediate lobes. Using morpholino oligonucleotides, we show that hypomorphic FGF3 down-regulation induces specific defects of pars intermedia POMC cells while pomc, growth hormone and prolactin expression remain intact in the pars distalis. This lineage-specific process is independent of the FGF3 effect on early pituitary specifying transcription factors as indicated by normal Lim3 and Pit1 expression in hypomorphic FGF3 morphants. These findings suggest that the FGF3 signal, in addition to its previously described role of regulating progenitor proliferation and survival, delineates the melanotrope and corticotrope lineage boundary, contributing to establishment of the pituitary pars distalis and pars intermedia. Author Affiliation: (a) Department of Medicine, Cedars-Sinai Research Institute, University of California Los Angeles, Los Angeles, California 90048, USA (b) Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California 90048, USA Article History: Received 23 August 2007; Revised 4 March 2008; Accepted 27 March 2008

Context: Mechanisms underlying pituitary corticotroph adenoma ACTH production are poorly understood, yet circulating ACTH levels closely correlate with adenoma phenotype and clinical outcomes.Objective: We characterized the 5' ends of proopiomelanocortin (POMC) gene transcripts, which encode the precursor polypeptide for ACTH, in order to investigate additional regulatory mechanisms of POMC gene transcription and ACTH production.Methods: We examined 11 normal human pituitary tissues, 32 ACTH-secreting tumors, as well as 6 silent pituitary corticotroph adenomas (SCA) that immunostain for but do not secrete ACTH.Results: We identified a novel regulatory region located near the intron2/exon3 junction in the human POMC gene, which functions as a second promoter and an enhancer. In vitro experiments demonstrated that CREB binds the second promoter and regulates its transcriptional activity. The second promoter is highly methylated in SCA, partially demethylated in normal pituitary tissue, and highly demethylated in pituitary and ectopic ACTH-secreting tumors. In contrast, the first promoter is demethylated in all POMC-expressing cells and is highly demethylated only in pituitary ACTH-secreting tumors harboring the USP8 mutation. Demethylation patterns of the second promoter correlate with clinical phenotypes of Cushing's disease.Conclusion: We identified a second POMC promoter regulated by methylation status in ACTH-secreting pituitary tumors. Our findings open new avenues for elucidating subcellular regulation of the hypothalamic-pituitary-adrenal axis and suggest the second POMC promoter may be a target for therapeutic intervention to suppress excess ACTH production. [ABSTRACT FROM AUTHOR]

As human and chimpanzee genomes show high homology for IGF1 and PRL , we analyzed the sera of 367 healthy chimpanzees obtained during routine physical examinations in a single colony and measured chimpanzee insulin-like growth factor (IGF)-1 and prolactin (PRL) levels across the lifespan using standard human immunoassays. Assuming chimpanzee IGF-1 levels peak during puberty as in humans, we randomly defined puberty as the age at which most IGF-1 levels were equal to or above the 90th percentile for each sex (males, ages ≥7.00 but <9.20 years; females, ≥5.00 but <8.00 years). IGF-1 levels steadily increased at a similar rate in juvenile males and females and peaked in puberty, strongly correlating with age, then slowly decreased faster in adult males than in adult females. As a group, males had a higher mean IGF-1 level than did females, but comparison by age category showed similar mean IGF-1 levels in males and females. PRL levels increased with age in females more than in males and levels were twice as high in females than in males. One pubertal male reported to have short stature had lower IGF-1 and weight compared with other males in the age group, confirming suspected growth hormone deficiency; a second male of normal height but low IGF-1 may have had delayed puberty. Overall, results show that differences in IGF-1 levels over the lifespan in this cohort of chimpanzees largely mimic those seen in humans, while patterns of PRL changes are less similar. [ABSTRACT FROM AUTHOR]

Purpose: Remission from Cushing disease (CD) after pituitary adenoma resection may be predicted by a postoperative reduction in serum cortisol level. A 2008 consensus statement recommends assessing morning cortisol levels during the first postoperative week, and replacing glucocorticoid (GC) if cortisol nadir of < 2 or < 5 µg/dL is achieved. We sought to evaluate adherence to consensus recommendations following adrenocorticotropic hormone (ACTH)-secreting pituitary adenoma resection at our tertiary medical center, and assess time to cortisol nadir to better define the window for assessment and intervention. Methods: We retrospectively analyzed data extracted from in-hospital electronic medical records for CD surgeries between January 1991 and September 2015. We compared cortisol levels and collection times, ACTH measurement, and postoperative and discharge GC treatment before and after consensus statement publication in July 2008. Results: 107 surgeries were performed in 92 patients with CD. After 2008, more surgeries had at least one cortisol value assessed (67.9% before vs. 91.3% after, p = 0.033), with median initial cortisol measurement at 14 h post-surgery. However, ACTH measurement remained unchanged (42.9% vs. 43.5%; p > 0.99). Cortisol collection during GC treatment tended to increase (32.7% vs. 57.1%; p = 0.068). Of surgeries performed without prior GC treatment, 31.7 and 55.0% had a cortisol nadir of < 2 and < 5 µg/dL, respectively, within 72 h postoperative. Conclusions: Our physicians were more diligent in measuring in-hospital postoperative cortisol levels consistent with 2008 consensus recommendations. Better management of cortisol measurements and their timing is an opportunity for improvement. [ABSTRACT FROM AUTHOR]