Mutation and genomic amplification of the PIK3CA proto-oncogene in pituitary adenomas
Contribuinte(s) |
UNIVERSIDADE DE SÃO PAULO |
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Data(s) |
04/11/2013
04/11/2013
2012
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Resumo |
The tumorigenesis of pituitary adenomas is poorly understood. Mutations of the PIK3CA proto-oncogene, which encodes the p110-α 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. |
Identificador |
Braz J Med Biol Res,v.45,n.9,p.851-855,2012 0100-879X http://www.producao.usp.br/handle/BDPI/38787 10.1590/S0100-879X2012007500115 http://www.scielo.br/scielo.php?script=sci_pdf&pid=S0100-879X2012000900009&lng=en&nrm=iso&tlng=en |
Idioma(s) |
eng |
Publicador |
Associação Brasileira de Divulgação Científica |
Relação |
Brazilian Journal of Medical and Biological Research |
Direitos |
openAccess |
Palavras-Chave | #Pituitary adenomas #PIK3CA proto-oncogene #Genomic amplification #Somatic mutation |
Tipo |
article original article |