Mutation and genomic amplification of the PIK3CA proto-oncogene in pituitary adenomas
| Autor: | Maria Lúcia Corrêa-Giannella, P.B.S. Braga, Maria Angela Zanella Fortes, Marcello D. Bronstein, Cahuê De Bernardis Murat, Ricardo Rodrigues Giorgi |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
Adenoma
Adult Male Adolescent Class I Phosphatidylinositol 3-Kinases Physiology Short Communication Immunology Biophysics Pituitary neoplasm Biology medicine.disease_cause Proto-Oncogene Mas Biochemistry Phosphatidylinositol 3-Kinases Young Adult Exon Germline mutation Gene duplication medicine Humans Pituitary Neoplasms General Pharmacology Toxicology and Pharmaceutics neoplasms lcsh:QH301-705.5 Pituitary adenomas Aged Genetics Mutation lcsh:R5-920 General Neuroscience Somatic mutation Gene Amplification Cell Biology General Medicine Middle Aged medicine.disease Immunohistochemistry PIK3CA proto-oncogene Genomic amplification lcsh:Biology (General) Cancer research Female Corticotropic cell Carcinogenesis lcsh:Medicine (General) Signal Transduction |
| Zdroj: | Brazilian Journal of Medical and Biological Research, Vol 45, Iss 9, Pp 851-855 (2012) Brazilian Journal of Medical and Biological Research, Volume: 45, Issue: 9, Pages: 851-855, Published: SEP 2012 Brazilian Journal of Medical and Biological Research v.45 n.9 2012 Brazilian Journal of Medical and Biological Research Associação Brasileira de Divulgação Científica (ABDC) instacron:ABDC |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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