O-6-methylguanine-DNA methyltransferase (MGMT) immunohistochemical expression in pituitary corticotroph adenomas [documento electrónico] / Luis Vicente Syro Moreno,  . - 2012.
Obra : Neurosurgery

Idioma : Inglés (eng)

Palabras clave :	Crooke cell adenoma  cushing disease  MGMT  pituitary adenoma  silent corticotroph adenoma  temozolomide
Resumen :	Background: O-6-methylguanine-DNA methyltransferase (MGMT) is a DNA repair enzyme that counteracts chemotherapeutic cytotoxicity of alkylating agents such as temozolomide. Low levels of MGMT expression have been shown to correlate with longer survival in glioma patients treated with temozolomide. The same is true in pi- tuitary adenomas. Objective: We investigated the immunohistochemical expression of MGMT in a variety of corticotroph adenoma subtypes to determine the potential utility of temozolomide as a therapeutic agent. Methods: The tumors consisted of 40 cases of adrenocorticotropin-secreting pituitary tumors in Cushing disease, 12 Crooke cell adenomas, and 7 subtype I silent corticotroph adenomas. Staining for MGMT was assessed by light microscopy; nuclear reactivity was estimated semiquantitatively as present in , 10%, 10% to 25%, 25% to 50%, 50% to 75%, and . 75% of cells. Results: Immunoexpression showed no correlation with patient age, sex, tumor size, invasiveness, or recurrence in patients with Cushing disease. Among adrenocorticotropin- ecreting adenomas associated with Cushing disease, most invasive (60%) and recurrent (86%) tumors showed low MGMT immunopositivity, defined as , 25%. Most (75%) Crooke cell adenomas exhibited an MGMT immunoreactivity of # 50%. All sub-type I silent corticotroph adenomas showed , 10% MGMT staining. Conclusion: Our descriptive findings of low MGMT expression in adrenocorticotropin-producing pituitary adenomas, particularly aggressive tumors, suggest that they may be suitable candidates for temozolomide therapy.
Mención de responsabilidad :	Fateme Salehi, Bernd W Scheithauer, Kalman Kovacs, Eva Horvath, Luis V Syro, Soniya Sharma, Branavan Manoranjan, Michael Cusimano
Referencia :	Neurosurgery. 2012 Feb;70(2):491-6.
DOI (Digital Object Identifier) :	10.1227/NEU.0b013e318230ac63
PMID :	21822153
En línea :	https://academic.oup.com/neurosurgery/article-abstract/70/2/491/2744231?redirect [...]
Enlace permanente :	https://hospitalpablotobon.cloudbiteca.com/pmb/opac_css/index.php?lvl=notice_display&id=3633