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1.
AACE Clin Case Rep ; 9(2): 39-43, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37056416

RESUMEN

Background/Objective: A thrombosed internal carotid artery (ICA) aneurysm mimicking a pituitary adenoma can be catastrophic if unrecognized. We report a unique case of the rare presentation of ICA aneurysms masquerading as pituitary adenomas, which can preserve pituitary function when treated early. Case Report: A 54-year-old man with type 2 diabetes, aortic valve replacement, and stroke presented with sudden onset severe headache and left eye pain. Left third nerve palsy was noted. Laboratory studies showed low thyroid-stimulating hormone, follicle-stimulating hormone, luteinizing hormone, testosterone, and insulin-like growth factor 1 levels and baseline, post-30-minute, and post-60-minute cortisol levels of 16, 17, and 14 µg/dL, respectively, after adrenocorticotropic hormone stimulation. Magnetic resonance imaging of the pituitary revealed a heterogeneously enhancing 2.0 × 2.1 × 2.1-cm sellar/suprasellar mass with peripheral enhancement abutting the left cavernous sinus. Given the acute third nerve palsy without visual defects and magnetic resonance imaging findings, other sources of sellar occupying etiology were suspected. Therefore, carotid cerebral angiography was performed and revealed a mostly thrombosed left ICA aneurysm projected into the sellar/suprasellar region. The patient underwent successful endovascular treatment with a resolution of the cranial nerve palsy and hormonal abnormalities at 3-month follow-up. Discussion: Our case demonstrates the importance of swift recognition of ICA aneurysms masquerading as pituitary adenomas. Early recognition and treatment may lead to the complete resolution of presenting symptoms and hormonal deficiencies. Conclusion: Clinicians should have a high index of suspicion for ICA aneurysm in the differential diagnosis for a sellar mass. Careful evaluation is essential because misdiagnosis may lead to catastrophic consequences.

2.
J Endocr Soc ; 7(4): bvad023, 2023 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-36860907

RESUMEN

Context: The COVID-19 pandemic challenged undertaking gradual educational activities for residency and fellowship trainees. However, recent technological advances have enabled broadening active learning opportunities through international online conferences. Objective: The format of our international online endocrine case conference, launched during the pandemic, is introduced. The objective impact of this program on trainees is described. Methods: Four academic facilities developed a semiannual international collaborative endocrinology case conference. Experts were invited as commentators to facilitate in-depth discussion. Six conferences were held between 2020 and 2022. After the fourth and sixth conferences, anonymous multiple-choice online surveys were administered to all attendees. Results: Participants included trainees and faculty. At each conference, 3 to 5 cases of rare endocrine diseases from up to 4 institutions were presented, mainly by trainees. Sixty-two percent of attendees reported 4 facilities as the appropriate size for the collaboration to maintain active learning in case conferences. Eighty-two percent of attendees preferred a semiannual conference. The survey also revealed the positive impact on trainees' learning regarding diversity of medical practice, academic career development, and confidence in honing of presentation skills. Conclusion: We present an example of our successful virtual global case conference to enhance learning about rare endocrine cases. For the success of the collaborative case conference, we suggest smaller cross-country institutional collaborations. Preferably, they would be international, semiannually based, and with recognized experts as commentators. Since our conference has engendered multiple positive effects on trainees and faculty, continuation of virtual education should be considered even after the pandemic era.

3.
J Neurol Surg B Skull Base ; 83(Suppl 2): e152-e159, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35832980

RESUMEN

Background Pituitary apoplexy after resection of giant pituitary adenomas is a rare but often cited morbidity associated with devastating outcomes. It presents as hemorrhage and/or infarction of residual tumor in the postoperative period. Because of its rarity, its incidence and consequences remain ill defined. Objective The aim of this study is to estimate the rate of postoperative pituitary apoplexy after resection of giant pituitary adenomas and assess the morbidity and mortality associated with apoplexy. Methods A systematic review of literature was performed to examine extent of resection in giant pituitary adenomas based on surgical approach, rate of postoperative apoplexy, morbidities, and mortality. Advantages and disadvantages of each approach were compared. Results Seventeen studies were included in quantitative analysis describing 1,031 cases of resection of giant pituitary adenomas. The overall rate of subtotal resection (<90%) for all surgical approaches combined was 35.6% (95% confidence interval: 28.0-43.1). Postoperative pituitary apoplexy developed in 5.65% ( n = 19) of subtotal resections, often within 24 hours and with a mortality of 42.1% ( n = 8). Resulting morbidities included visual deficits, altered consciousness, cranial nerve palsies, and convulsions. Conclusion Postoperative pituitary apoplexy is uncommon but is associated with high rates of morbidity and mortality in subtotal resection cases. These findings highlight the importance in achieving a maximal resection in a time sensitive fashion to mitigate the severe consequences of postoperative apoplexy.

4.
AACE Clin Case Rep ; 8(5): 204-209, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35754921

RESUMEN

Background/Objective: Although SARS-CoV-2 vaccines have been developed with multiple novel technologies and rapidly disseminated worldwide, the full profile of adverse effects has not been known. Recently, there are sporadic but increasing reports of endocrinopathy in relation to SARS-CoV-2 vaccination. Here we report a rare case of hypophysitis with acute onset of diabetes insipidus, immediately after SARS-CoV-2 vaccination. Case Report: A 48-year-old female patient had been in her usual state of health until she received the first SARS-CoV-2 vaccine. Two days after vaccination, she started to have flu-like symptoms, including severe headache and myalgia as well as persistent headache, polydipsia, and polyuria. She was diagnosed with diabetes insipidus, and magnetic resonance imaging revealed thickening of the pituitary stalk. Three months after vaccination, her symptoms had somewhat improved, but she still had pituitary stalk thickening on magnetic resonance imaging. Discussion: Given the timing of the occurrence of diabetes insipidus, we believe that the patient's hypophysitis may be associated with SARS-CoV-2 vaccination. We also found 19 cases of endocrinopathy after SARS-CoV-2 vaccination by literature search. The reported endocrine organs were the thyroid, pituitary, and adrenals. Twelve cases of diabetes were also reported. Among 3 pituitary cases, diabetes insipidus was reported only in our case. Conclusion: We report a rare case of SARS-CoV-2 vaccine-triggered hypophysitis, which led to diabetes insipidus. SARS-CoV-2 vaccine-related endocrinopathy seems, indeed, possible. Endocrinopathy is associated with infrequent complications; however, it may be underestimated in the post-SARS-CoV-2-vaccinated population. Further studies are warranted to better understand SARS-CoV-2 vaccine-related endocrinopathy.

5.
Endocrinology ; 163(8)2022 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-35678423

RESUMEN

Nonsurgical medical treatments are often performed for Cushing's disease due to high recurrence rates. However, current medical treatment that targets corticotroph adenomas are limited. To develop a treatment that specifically targets corticotrophs in Cushing's disease, it is necessary to identify corticotroph lineage-specific proteins, which are involved in the Cushing's tumor phenotype. We have previously reported that the expression of E2F transcription factor 1 (E2F1), one of the cell cycle regulatory proteins, was increased in corticotrophs in Cushing's disease model mice and was involved in the regulation of POMC gene expression. Phosphorylation of Ser337 of E2F1 (pS337-E2F1) facilitates its binding to the POMC promoter, which was suggested to contribute to elevated POMC expression in corticotrophs. Here, we report that E2F1 expression is specific to the corticotroph lineage in normal human pituitaries and that the E2F1 protein is localized in the cytosol in normal corticotrophs. We show that pS337-E2F1 is localized in the nucleus specifically in Cushing's tumors, while it is localized in the perinuclear cytoplasm in the normal pituitary. This observation demonstrates that pS337 is a marker for Cushing's tumors and suggests that phosphorylation of E2F1 may be a target for developing a novel pharmacological treatment for tumorigenesis and hormone dysregulation of Cushing's disease.


Asunto(s)
Adenoma Hipofisario Secretor de ACTH , Adenoma , Factor de Transcripción E2F1 , Hipersecreción de la Hormona Adrenocorticotrópica Pituitaria (HACT) , Neoplasias Hipofisarias , Adenoma Hipofisario Secretor de ACTH/tratamiento farmacológico , Adenoma Hipofisario Secretor de ACTH/metabolismo , Adenoma/metabolismo , Hormona Adrenocorticotrópica/metabolismo , Animales , Factor de Transcripción E2F1/metabolismo , Ratones , Hipersecreción de la Hormona Adrenocorticotrópica Pituitaria (HACT)/tratamiento farmacológico , Neoplasias Hipofisarias/metabolismo , Neoplasias Hipofisarias/patología , Proopiomelanocortina/metabolismo
6.
J Clin Endocrinol Metab ; 106(9): e3346-e3363, 2021 08 18.
Artículo en Inglés | MEDLINE | ID: mdl-34061962

RESUMEN

CONTEXT: Mechanisms underlying pituitary corticotroph adenoma adrenocorticotropin (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 corticotroph adenomas (SCAs) that immunostain for but do not secrete ACTH. RESULTS: We identified a novel regulatory region located near the intron 2/exon 3 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 SCAs, 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 ubiquitin-specific protease 8 (USP8) mutation. Demethylation patterns of the second promoter correlate with clinical phenotypes of Cushing 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.


Asunto(s)
Hipersecreción de la Hormona Adrenocorticotrópica Pituitaria (HACT)/genética , Proopiomelanocortina/genética , Regiones Promotoras Genéticas/genética , Adenoma Hipofisario Secretor de ACTH/sangre , Adenoma/metabolismo , Adolescente , Hormona Adrenocorticotrópica/sangre , Hormona Adrenocorticotrópica/genética , Adulto , Anciano , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/sangre , Exones , Femenino , Regulación de la Expresión Génica , Humanos , Sistema Hipotálamo-Hipofisario/fisiopatología , Masculino , Neoplasias Hipofisarias/metabolismo , Sistema Hipófiso-Suprarrenal/fisiopatología , Resultado del Tratamiento , Adulto Joven
7.
Pituitary ; 24(6): 859-866, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34041660

RESUMEN

PURPOSE: Pituitary apoplexy is a rare endocrine emergency. The purpose of this study is to characterize physiological changes involved in pituitary apoplexy, especially during the acute phase. METHODS: A Cushing's disease patient experienced corticotroph releasing hormone (CRH)-induced pituitary apoplexy during inferior petrosal sinus sampling (IPSS). The IPSS blood samples from the Cushing's disease patient were retrospectively analyzed for cytokine markers. For comparison, we also analyzed cytokine markers in blood samples from two pituitary ACTH-secreting microadenoma patients and one patient with an ectopic ACTH-secreting tumor. RESULTS: Acute elevation of interleukin 6 (IL-6) and matrix metalloproteinase 9 (MMP9) was observed in the IPSS blood sample on the apoplectic hemorrhagic site of the tumor. In contrast, such a change was not observed in the blood samples from the contralateral side of the apoplexy patient and in other IPSS samples from two non-apoplexy Cushing's disease patient and a patient with ectopic Cushing's syndrome. CONCLUSION: IL-6 and MMP9 may be involved in the acute process of pituitary apoplexy in Cushing's disease.


Asunto(s)
Adenoma , Interleucina-6 , Metaloproteinasa 9 de la Matriz , Hipersecreción de la Hormona Adrenocorticotrópica Pituitaria (HACT) , Apoplejia Hipofisaria , Neoplasias Hipofisarias , Hormona Liberadora de Corticotropina , Humanos , Muestreo de Seno Petroso , Estudios Retrospectivos
8.
Front Endocrinol (Lausanne) ; 12: 624686, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33841328

RESUMEN

Up to 35% of aggressive pituitary tumors recur and significantly affect mortality and quality of life. Management can be challenging and often requires multimodal treatment. Current treatment options, including surgery, conventional medical therapies such as dopamine agonists, somatostatin receptor agonists and radiotherapy, often fail to inhibit pituitary tumor growth. Recently, anti-tumor effects of chemotherapeutic drugs such as Temozolomide, Capecitabine, and Everolimus, as well as peptide receptor radionuclide therapy on aggressive pituitary tumors have been increasingly investigated and yield mixed, although sometimes promising, outcomes. The purpose of this review is to provide thorough information on non-surgical medical therapies and their efficacies and used protocols for aggressive pituitary adenomas from pre-clinical level to clinical use.


Asunto(s)
Antineoplásicos/uso terapéutico , Agonistas de Dopamina/uso terapéutico , Neoplasias Hipofisarias/terapia , Capecitabina/uso terapéutico , Terapia Combinada , Humanos , Neoplasias Hipofisarias/patología , Temozolomida/uso terapéutico , Resultado del Tratamiento
9.
J Endocr Soc ; 4(9): bvaa089, 2020 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-32783016

RESUMEN

Pituitary collision tumors are sporadically reported and rare. We present a case of pituitary collision tumors with nonfunctioning pituitary adenoma (NFPA) and craniopharyngioma. In order to look for any common activated pathway, we examined WNT/ß-CATENIN signaling activation, known to be involved in tumorigenesis in both craniopharyngioma and NFPA. We found nuclear accumulation of ß-CATENIN protein and expression of LEF1 protein, markers of active ß-CATENIN signaling in the craniopharyngioma but not in the pituitary adenomas. In our case, the NFPA is invasive macroadenoma, which is a frequently identified type of pituitary adenoma in collision tumor cases. Recurrence of this tumor was first observed after 8 years of follow-up. Based on this case, we suggest that pituitary collision tumors require long-term follow-up.

10.
J Clin Endocrinol Metab ; 105(9)2020 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-32754748

RESUMEN

CONTEXT: Combination therapy with somatostatin receptor ligand (SRL) plus pegvisomant for patients with acromegaly is recommended after a maximizing dose on monotherapy. Lower-dose combination regimens are not well studied. OBJECTIVE: To compare cost-effectiveness and efficacy of 3 lower-dose combination regimens in controlled and uncontrolled acromegaly. DESIGN AND SETTING: Prospective, randomized, open-label, parallel arm study at a tertiary referral pituitary center. PATIENTS: Adults with acromegaly regardless of response to prior SRL and biochemical control status at baseline, stratified by an SRL dose required for insulin-like growth factor (IGF)-I normalization during any 3-month period within 12 months preceding enrollment. INTERVENTION: Combination therapy for 24 to 32 weeks on arm A, high-dose SRL (lanreotide 120 mg/octreotide long-acting release [LAR] 30 mg) plus weekly pegvisomant (40-160 mg/week); arm B, low-dose SRL (lanreotide 60 mg/octreotide LAR 10 mg) plus weekly pegvisomant; or arm C, low-dose SRL plus daily pegvisomant (15-60 mg/day). MAIN OUTCOME MEASURE: Monthly treatment cost in each arm in participants completing ≥ 24 weeks of therapy. RESULTS: Sixty patients were enrolled and 52 were evaluable. Fifty of 52 (96%) demonstrated IGF-I control regardless of prior SRL responsiveness (arm A, 14/15 [93.3%]; arm B, 22/23 [95.7%]; arm C, 14/14 [100%]). Arm B was least costly (mean, $9837 ±â€…1375 per month), arm C was most expensive (mean, $22543 ±â€…11158 per month), and arm A had an intermediate cost (mean, $14261 ±â€…1645 per month). Approximately 30% of patients required pegvisomant dose uptitration. Rates of adverse events were all < 10%. CONCLUSIONS: Low-dose SRL plus weekly pegvisomant represents a novel dosing option for achieving cost-effective, optimal biochemical control in patients with uncontrolled acromegaly requiring combination therapy.


Asunto(s)
Acromegalia/tratamiento farmacológico , Acromegalia/economía , Hormona de Crecimiento Humana/análogos & derivados , Octreótido/administración & dosificación , Péptidos Cíclicos/administración & dosificación , Somatostatina/análogos & derivados , Adulto , Análisis Costo-Beneficio , Preparaciones de Acción Retardada , Formas de Dosificación , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Costos de los Medicamentos , Quimioterapia Combinada/efectos adversos , Quimioterapia Combinada/economía , Femenino , Hormona de Crecimiento Humana/administración & dosificación , Hormona de Crecimiento Humana/efectos adversos , Hormona de Crecimiento Humana/economía , Humanos , Masculino , Persona de Mediana Edad , Octreótido/efectos adversos , Octreótido/economía , Péptidos Cíclicos/efectos adversos , Péptidos Cíclicos/economía , Receptores de Somatostatina/agonistas , Somatostatina/administración & dosificación , Somatostatina/efectos adversos , Somatostatina/economía , Terapias en Investigación/efectos adversos , Terapias en Investigación/economía , Terapias en Investigación/métodos , Resultado del Tratamiento
12.
Artículo en Inglés | MEDLINE | ID: mdl-30147673

RESUMEN

Cell cycle proteins are critical to pituitary development, but their contribution to lineage-specific tumorigenesis has not been well-elucidated. Emerging evidence from in vitro human tumor analysis and transgenic mouse models indicates that G1/S-related cell cycle proteins, particularly cyclin E, p27, Rb, and E2F1, drive molecular mechanisms that underlie corticotroph-specific differentiation and development of Cushing disease. The aim of this review is to summarize the literature and discuss the complex role of cell cycle regulation in Cushing disease, with a focus on identifying potential targets for therapeutic intervention in patients with these tumors.

13.
AACE Clin Case Rep ; 4(5): e375-e378, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-31897433

RESUMEN

OBJECTIVE: Ectopic Cushing's syndrome secondary to thymic carcinoid is a rare disorder that may be difficult to diagnose and manage. METHODS: We describe a case of severe Cushing's syndrome secondary to a large adrenocorticotropic hormone (ACTH) producing thymic carcinoid in a patient with history of primary hyperaldosteronism. RESULTS: A 43-year-old female with a 20-year history of an aldosterone-secreting adrenocortical adenoma status post right adrenalectomy presented with acute onset of proximal muscle weakness, swelling, facial hirsutism, and severe hypokalemia. Ectopic Cushing's Syndrome was suspected based on the sudden symptom onset and markedly elevated 24-hr urine cortisol and ACTH levels. MRI revealed an empty pituitary sella and a large (7.3 cm) mediastinal mass visible on chest CT. The mass was resected by video-assisted thoracoscopic surgery, resulting in resolution of symptoms and cortisol levels. Pathology assessment confirmed well-differentiated thymic carcinoid with positive ACTH staining. CONCLUSION: The case highlights clinical features, challenges in diagnostic work up, treatment modalities, and associated endocrine findings in a thymic carcinoid abutting the heart and presenting with ectopic ACTH secretion.

14.
J Endocr Soc ; 1(2): 127-143, 2017 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-29264472

RESUMEN

The epidermal growth factor receptor (EGFR), expressed in adrenocorticotrophic hormone (ACTH)-secreting pituitary adenomas causing Cushing disease, regulates ACTH production and corticotroph proliferation. To elucidate the utility of EGFR as a therapeutic target for Cushing disease, we generated transgenic (Tg) mice with corticotroph-specific human EGFR expression (corti-EGFR-Tg) using a newly constructed corticotroph-specific promoter. Pituitary-specific EGFR expression was observed by 2.5 months, and aggressive ACTH-secreting pituitary adenomas with features of Crooke's cells developed by 8 months with 65% penetrance observed. Features consistent with the Cushing phenotype included elevated plasma ACTH and corticosterone levels, increased body weight, glucose intolerance, and enlarged adrenal cortex. Gefitinib, an EGFR tyrosine kinase inhibitor, suppressed tumor POMC expression and downstream EGFR tumor signaling, and ACTH and corticosterone levels were attenuated by 80% and 78%, respectively. Both E2F1 and phosphorylated Ser-337 E2F1 were increased in corti-EGFR-Tg mice and also colocalized with human POMC (hPOMC) in human pituitary corticotroph tumor samples. EGFR inhibition reversed E2F1 activity in vivo, whereas E2F1 inhibition suppressed POMC and ACTH in cultured human pituitary tumor cells. The corti-EGFR-Tg phenotype recapitulates ACTH-secreting pituitary adenomas and Cushing disease, validating the relevance of EGFR to corticotroph tumorigenesis. E2F1 is identified as a promising corticotroph-specific target for ACTH-dependent Cushing disease.

15.
Endocr Relat Cancer ; 23(11): 857-870, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27935805

RESUMEN

Cushing's syndrome is caused by excessive adrenocorticotropic hormone (ACTH) secretion derived from pituitary corticotroph tumors (Cushing disease) or from non-pituitary tumors (ectopic Cushing's syndrome). Hypercortisolemic features of ectopic Cushing's syndrome are severe, and no definitive treatment for paraneoplastic ACTH excess is available. We aimed to identify subcellular therapeutic targets by elucidating transcriptional regulation of the human ACTH precursor POMC (proopiomelanocortin) and ACTH production in non-pituitary tumor cells and in cell lines derived from patients with ectopic Cushing's syndrome. We show that ectopic hPOMC transcription proceeds independently of pituitary-specific Tpit/Pitx1 and demonstrate a novel E2F1-mediated transcriptional mechanism regulating hPOMC We identify an E2F1 cluster binding to the proximal hPOMC promoter region (-42 to +68), with DNA-binding activity determined by the phosphorylation at Ser-337. hPOMC mRNA expression in cancer cells was upregulated (up to 40-fold) by the co-expression of E2F1 and its heterodimer partner DP1. Direct and indirect inhibitors of E2F1 activity suppressed hPOMC gene expression and ACTH by modifying E2F1 DNA-binding activity in ectopic Cushing's cell lines and primary tumor cells, and also suppressed paraneoplastic ACTH and cortisol levels in xenografted mice. E2F1-mediated hPOMC transcription is a potential target for suppressing ACTH production in ectopic Cushing's syndrome.


Asunto(s)
Síndrome de ACTH Ectópico/genética , Tumor Carcinoide/genética , Factor de Transcripción E2F1/fisiología , Neoplasias Pulmonares/genética , Proopiomelanocortina/genética , Adenoma Hipofisario Secretor de ACTH/genética , Adenoma Hipofisario Secretor de ACTH/metabolismo , Adenoma/genética , Adenoma/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Animales , Tumor Carcinoide/metabolismo , Células Cultivadas , Síndrome de Cushing/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Pulmonares/metabolismo , Masculino , Ratones , Persona de Mediana Edad , Proopiomelanocortina/metabolismo , Adulto Joven
16.
Proc Natl Acad Sci U S A ; 113(23): E3250-9, 2016 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-27226307

RESUMEN

Growth hormone (GH) excess in acromegaly is associated with increased precancerous colon polyps and soft tissue adenomas, whereas short-stature humans harboring an inactivating GH receptor mutation do not develop cancer. We show that locally expressed colon GH is abundant in conditions predisposing to colon cancer and in colon adenocarcinoma-associated stromal fibroblasts. Administration of a GH receptor (GHR) blocker in acromegaly patients induced colon p53 and adenomatous polyposis coli (APC), reversing progrowth GH signals. p53 was also induced in skin fibroblasts derived from short-statured humans with mutant GHR. GH-deficient prophet of pituitary-specific positive transcription factor 1 (Prop1)(-/-) mice exhibited induced colon p53 levels, and cross-breeding them with Apc(min+/-) mice that normally develop intestinal and colon tumors resulted in GH-deficient double mutants with markedly decreased tumor number and size. We also demonstrate that GH suppresses p53 and reduces apoptosis in human colon cell lines as well as in induced human pluripotent stem cell-derived intestinal organoids, and confirm in vivo that GH suppresses colon mucosal p53/p21. GH excess leads to decreased colon cell phosphatase and tensin homolog deleted on chromosome 10 (PTEN), increased cell survival with down-regulated APC, nuclear ß-catenin accumulation, and increased epithelial-mesenchymal transition factors and colon cell motility. We propose that GH is a molecular component of the "field change" milieu permissive for neoplastic colon growth.


Asunto(s)
Neoplasias del Colon/metabolismo , Hormona del Crecimiento/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Acromegalia/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Animales , Línea Celular Tumoral , Colon/metabolismo , Transición Epitelial-Mesenquimal , Femenino , Fibroblastos/metabolismo , Humanos , Masculino , Ratones Transgénicos , Persona de Mediana Edad , Mutación , Fosfohidrolasa PTEN/metabolismo , Receptores de Somatotropina/genética , Piel/citología , Proteína p53 Supresora de Tumor/genética , Adulto Joven , beta Catenina/metabolismo
17.
J Clin Endocrinol Metab ; 100(7): 2557-64, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25942479

RESUMEN

CONTEXT: Cushing disease, due to pituitary corticotroph tumor ACTH hypersecretion, drives excess adrenal cortisol production with adverse morbidity and mortality. Loss of glucocorticoid negative feedback on the hypothalamic-pituitary-adrenal axis leads to autonomous transcription of the corticotroph precursor hormone proopiomelanocortin (POMC), consequent ACTH overproduction, and adrenal hypercortisolism. We previously reported that R-roscovitine (CYC202, seliciclib), a 2,6,9-trisubstituted purine analog, suppresses cyclin-dependent-kinase 2/cyclin E and inhibits ACTH in mice and zebrafish. We hypothesized that intrapituitary cyclin E signaling regulates corticotroph tumor POMC transcription independently of cell cycle progression. The aim was to investigate whether R-roscovitine inhibits human ACTH in corticotroph tumors by targeting the cyclin-dependent kinase 2/cyclin E signaling pathway. METHODS: Primary cell cultures of surgically resected human corticotroph tumors were treated with or without R-roscovitine, ACTH measured by RIA and quantitative PCR, and/or Western blot analysis performed to investigate ACTH and lineage-specific transcription factors. Cyclin E and E2F transcription factor 1 (E2F1) small interfering RNA (siRNA) transfection was performed in murine corticotroph tumor AtT20 cells to elucidate mechanisms for drug action. POMC gene promoter activity in response to R-roscovitine treatment was analyzed using luciferase reporter and chromatin immunoprecipitation assays. RESULTS: R-roscovitine inhibits human corticotroph tumor POMC and Tpit/Tbx19 transcription with decreased ACTH expression. Cyclin E and E2F1 exhibit reciprocal positive regulation in corticotroph tumors. R-roscovitine disrupts E2F1 binding to the POMC gene promoter and suppresses Tpit/Tbx19 and other lineage-specific POMC transcription cofactors via E2F1-dependent and -independent pathways. CONCLUSION: R-roscovitine inhibits human pituitary corticotroph tumor ACTH by targeting the cyclin E/E2F1 pathway. Pituitary cyclin E/E2F1 signaling is a previously unappreciated molecular mechanism underlying neuroendocrine regulation of the hypothalamic-pituitary-adrenal axis, providing a subcellular therapeutic target for small molecule cyclin-dependent kinase 2 inhibitors of pituitary ACTH-dependent hypercortisolism, ie, Cushing disease.


Asunto(s)
Antineoplásicos/uso terapéutico , Ciclina E/antagonistas & inhibidores , Terapia Molecular Dirigida/métodos , Hipersecreción de la Hormona Adrenocorticotrópica Pituitaria (HACT)/tratamiento farmacológico , Proopiomelanocortina/genética , Purinas/uso terapéutico , Adenoma Hipofisario Secretor de ACTH/complicaciones , Adenoma Hipofisario Secretor de ACTH/tratamiento farmacológico , Adenoma Hipofisario Secretor de ACTH/genética , Adenoma Hipofisario Secretor de ACTH/patología , Adenoma/complicaciones , Adenoma/tratamiento farmacológico , Adenoma/genética , Adenoma/patología , Adolescente , Adulto , Anciano , Ciclina E/fisiología , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Masculino , Hipersecreción de la Hormona Adrenocorticotrópica Pituitaria (HACT)/patología , Cultivo Primario de Células , Proopiomelanocortina/metabolismo , Roscovitina , Células Tumorales Cultivadas , Adulto Joven
18.
Endocrinology ; 156(1): 71-9, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25375038

RESUMEN

As ErbB receptors are expressed in prolactinomas and exhibit downstream effects on prolactin (PRL) production and cell proliferation, we generated transgenic mice using a PRL enhancer/promoter expression system to restrict lactotroph-specific expression of human epidermal growth factor receptor (EGFR) or human EGFR2 (HER2). EGFR or HER2 transgenic mice developed prolactinomas between 13 and 15 months, and confocal immunofluorescence and Western blot analysis confirmed lactotroph-restricted PRL and EGFR or HER2 coexpression. Circulating PRL levels in EGFR and HER2 transgenic mice were increased 5- and 3.8-fold, respectively. Inhibiting EGFR or HER2 signaling with oral lapatinib (100 mg/kg), a dual tyrosine kinase inhibitor for both EGFR and HER2, suppressed circulating PRL by 72% and attenuated tumor PRL expression by 80% and also attenuated downstream tumor EGFR/HER2 signaling. This model demonstrates the role of ErbB receptors underlying prolactinoma tumorigenesis and the feasibility of targeting these receptors for translation to treatment of refractory prolactinomas.


Asunto(s)
Antineoplásicos/uso terapéutico , Receptores ErbB/metabolismo , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Neoplasias Hipofisarias/tratamiento farmacológico , Prolactinoma/tratamiento farmacológico , Quinazolinas/uso terapéutico , Animales , Elementos de Facilitación Genéticos , Receptores ErbB/genética , Femenino , Regulación Neoplásica de la Expresión Génica/fisiología , Humanos , Lapatinib , Ratones , Ratones Transgénicos , Neoplasias Hipofisarias/genética , Neoplasias Hipofisarias/metabolismo , Prolactinoma/genética , Prolactinoma/metabolismo , Regiones Promotoras Genéticas
19.
J Diabetes ; 6(4): 360-8, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24330072

RESUMEN

BACKGROUND: Elevated insulin, C-reactive protein (CRP), tumor necrosis factor (TNF)-α, interleukin (IL)-6, and monocyte chemoattractant protein (MCP)-1 levels and decreased high molecular weight adiponectin (HMW-APN) levels have been reported in Caucasians with gestational diabetes mellitus (GDM). No similar studies have been performed in Chinese women. METHODS: Serum samples were obtained 1 h after a 50-g glucose challenge test (1HGCT) from Chinese-American women at 24-28 gestational weeks and total adiponectin (T-APN), HMW-APN, CRP, TNF-α, IL-6, and MCP-1 concentrations were measured. Correlation coefficients for glucose (1HGCT), HbA1c, insulin, and body mass index (BMI) were calculated against T-APN, HMW-APN, CRP, TNF-α, IL-6, and MCP-1. Significant P-values were determined using Bonferroni adjustments. RESULTS: Women with GDM had higher insulin and 1HGCT and lower T-APN. In addition, T-APN was lower in non-GDM subjects who had 1HGCT ≥135 mg/dL with no abnormal or one abnormal glucose value on the 3-h oral glucose tolerance test. There were no significant differences in HMW-APN and inflammatory marker levels between non-GDM and GDM groups. There were negative correlations between T-APN and 1HGCT, insulin, BMI, and HbA1c, as well as between HMW-APN and 1HGCT, insulin, and BMI. No significant correlations were observed between 1HGCT, HbA1c, insulin, or BMI and CRP, TNF-α, IL-6, or MCP-1. CONCLUSIONS: T-APN is reduced in Chinese women with GDM and those without GDM but with evidence of glucose intolerance. Unlike results reported for Caucasians, Chinese-American women with GDM do not exhibit elevated levels of CRP, TNF-α, IL-6, or MCP-1, possibly because Chinese women are relatively leaner compared with Caucasians.


Asunto(s)
Adiponectina/sangre , Biomarcadores/sangre , Proteína C-Reactiva/metabolismo , Quimiocina CCL2/sangre , Diabetes Gestacional/diagnóstico , Intolerancia a la Glucosa/diagnóstico , Interleucina-6/sangre , Factor de Necrosis Tumoral alfa/sangre , Adolescente , Adulto , Asiático , Glucemia/análisis , Diabetes Gestacional/sangre , Ensayo de Inmunoadsorción Enzimática , Femenino , Estudios de Seguimiento , Intolerancia a la Glucosa/sangre , Hemoglobina Glucada/análisis , Humanos , Embarazo , Pronóstico , Adulto Joven
20.
Endocrinol Metab Clin North Am ; 40(4): 865-94, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22108285

RESUMEN

Polycystic ovary syndrome (PCOS) is a disease of complex and still poorly understood cause and of variable phenotypes. It is characterized by anovulation, hyperandrogenism, and polycystic ovaries. Infertility is commonly present. A variety of methods has been used successfully to achieve pregnancy in women with PCOS. Maintenance of pregnancy is complicated by a higher rate of premature spontaneous abortions and high risk of gestational diabetes, hypertension, and preeclampsia. However, with careful monitoring and treatment, the outcome of pregnancy in most women with PCOS is excellent.


Asunto(s)
Infertilidad Femenina/etiología , Infertilidad Femenina/terapia , Síndrome del Ovario Poliquístico/complicaciones , Aborto Espontáneo , Adulto , Dieta , Ejercicio Físico , Femenino , Fertilización In Vitro , Humanos , Hiperandrogenismo , Recién Nacido , Resistencia a la Insulina , Masculino , Inducción de la Ovulación , Síndrome del Ovario Poliquístico/diagnóstico , Síndrome del Ovario Poliquístico/terapia , Embarazo , Complicaciones del Embarazo , Resultado del Embarazo , Pérdida de Peso
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