Mutation and genomic amplification of the PIK3CA proto-oncogene in pituitary adenomas
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...
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Associação Brasileira de Divulgação Científica
2012-09-01
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| Series: | Brazilian Journal of Medical and Biological Research |
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| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012000900009 |
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| author | C.B. Murat P.B.S. Braga M.A.H.Z. Fortes M.D. Bronstein M.L.C. Corrêa-Giannella R.R. Giorgi |
| author_facet | C.B. Murat P.B.S. Braga M.A.H.Z. Fortes M.D. Bronstein M.L.C. Corrêa-Giannella R.R. Giorgi |
| author_sort | C.B. Murat |
| collection | DOAJ |
| description | 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. |
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| institution | Directory Open Access Journal |
| issn | 0100-879X 1414-431X |
| language | English |
| last_indexed | 2024-12-20T19:53:17Z |
| publishDate | 2012-09-01 |
| publisher | Associação Brasileira de Divulgação Científica |
| record_format | Article |
| series | Brazilian Journal of Medical and Biological Research |
| spelling | doaj.art-d0ca0882359a4b0a91caf5221f9bc1322022-12-21T19:28:15ZengAssociação Brasileira de Divulgação CientíficaBrazilian Journal of Medical and Biological Research0100-879X1414-431X2012-09-01459851855Mutation and genomic amplification of the PIK3CA proto-oncogene in pituitary adenomasC.B. MuratP.B.S. BragaM.A.H.Z. FortesM.D. BronsteinM.L.C. Corrêa-GiannellaR.R. GiorgiThe 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.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012000900009Pituitary adenomasPIK3CA proto-oncogeneGenomic amplificationSomatic mutation |
| spellingShingle | C.B. Murat P.B.S. Braga M.A.H.Z. Fortes M.D. Bronstein M.L.C. Corrêa-Giannella R.R. Giorgi Mutation and genomic amplification of the PIK3CA proto-oncogene in pituitary adenomas Brazilian Journal of Medical and Biological Research Pituitary adenomas PIK3CA proto-oncogene Genomic amplification Somatic mutation |
| title | Mutation and genomic amplification of the PIK3CA proto-oncogene in pituitary adenomas |
| title_full | Mutation and genomic amplification of the PIK3CA proto-oncogene in pituitary adenomas |
| title_fullStr | Mutation and genomic amplification of the PIK3CA proto-oncogene in pituitary adenomas |
| title_full_unstemmed | Mutation and genomic amplification of the PIK3CA proto-oncogene in pituitary adenomas |
| title_short | Mutation and genomic amplification of the PIK3CA proto-oncogene in pituitary adenomas |
| title_sort | mutation and genomic amplification of the pik3ca proto oncogene in pituitary adenomas |
| topic | Pituitary adenomas PIK3CA proto-oncogene Genomic amplification Somatic mutation |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012000900009 |
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