Please use this identifier to cite or link to this item: https://observatorio.fm.usp.br/handle/OPI/517
Title: Mutation and genomic amplification of the PIK3CA proto-oncogene in pituitary adenomas
Authors: MURAT, C. B.BRAGA, P. B. S.FORTES, M. A. H. Z.BRONSTEIN, M. D.CORREA-GIANNELLA, M. L. C.GIORGI, R. R.
Citation: BRAZILIAN JOURNAL OF MEDICAL AND BIOLOGICAL RESEARCH, v.45, n.9, p.851-855, 2012
Abstract: The tumorigenesis of pituitary adenomas is poorly understood. Mutations of the PIK3CA proto-oncogene, which encodes the p110-alpha catalytic subunit of PI3K, have been reported in various types of human cancers regarding the role of the gene in cell proliferation and survival through activation of the PI3K/Akt signaling pathway. Only one Chinese study described somatic mutations and amplification of the PIK3CA gene in a large series of pituitary adenomas. The aim of the present study was to determine genetic alterations of PIK3CA in a second series that consisted of 33 pituitary adenomas of different subtypes diagnosed by immunohistochemistry: 6 adrenocorticotropic hormone-secreting microadenomas, 5 growth hormone-secreting macroadenomas, 7 prolactin-secreting macroadenomas, and 15 nonfunctioning macroadenomas. Direct sequencing of exons 9 and 20 assessed by qPCR was employed to investigate the presence of mutations and genomic amplification defined as a copy number >= 4. Previously identified PIK3CA mutations (exon 20) were detected in four cases (12.1%). Interestingly, the Chinese study reported mutations only in invasive tumors, while we found a PIK3CA mutation in one noninvasive corticotroph microadenoma. PIK3CA amplification was observed in 21.2% (7/33) of the cases. This study demonstrates the presence of somatic mutations and amplifications of the PIK3CA gene in a second series of pituitary adenomas, corroborating the previously described involvement of the PI3K/Akt signaling pathway in the tumorigenic process of this gland.
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Artigos e Materiais de Revistas Científicas - FM/MCM
Departamento de Clínica Médica - FM/MCM

Artigos e Materiais de Revistas Científicas - HC/ICHC
Instituto Central - HC/ICHC

Artigos e Materiais de Revistas Científicas - LIM/25
LIM/25 - Laboratório de Endocrinologia Celular e Molecular


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