Genomic gain of PIK3CA and increased expression of p110alpha are associated with progression of dysplasia into invasive squamous cell carcinoma.
J Pathol
; 198(3): 335-42, 2002 Nov.
Article
en En
| MEDLINE
| ID: mdl-12375266
PIK3CA, encoding the catalytic subunit p110alpha of phosphatidylinositol 3-kinase (PI3K), is activated in malignant diseases. However, the role of the PIK3CA gene aberrations for tumourigenesis of head and neck squamous cell carcinoma (HNSCC) is to date unclear. The present study was designed to determine the genomic aberration of PIK3CA in invasive HNSCC and dysplastic precursor lesions by fluorescence in situ hybridization (FISH) with a YAC probe, containing the PIK3CA gene, on isolated interphase nuclei from histomorphologically well-defined regions of formalin-fixed tissue sections and to compare these data with protein and mRNA expression of p110alpha. The mRNA and protein levels of p110alpha were assessed, respectively, by in situ hybridization and immunohistochemistry on consecutive tissue sections. Copy number gains at 3q26 were observed in one of six low-to-moderate dysplasias (17%) and in seven of nine high-grade dysplasias (78%), as well as in 11 carcinomas (100%). In addition, one of seven high-grade dysplasias (14%) and 6 of 11 carcinomas (55%) had amplifications of 3q26. The majority of cases with copy number gain in more than 50% of the cells and/or amplification in more than 10% of cells showed increased p110alpha mRNA and protein expression, whereas only two cases (18%) (one high-grade dysplasia and one carcinoma) with no gain or low-level gain displayed increased p110alpha protein expression. These data suggest that 3q26 copy number gain and amplification represent early genomic aberrations in HNSCC carcinogenesis. In addition, p110alpha mRNA and protein expression in HNSCC may be regulated by these genomic aberrations as well as by epigenetic events.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Lesiones Precancerosas
/
Carcinoma de Células Escamosas
/
Aberraciones Cromosómicas
/
Fosfatidilinositol 3-Quinasas
/
Neoplasias de Cabeza y Cuello
Tipo de estudio:
Risk_factors_studies
Límite:
Adult
/
Aged
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
J Pathol
Año:
2002
Tipo del documento:
Article
País de afiliación:
Alemania
Pais de publicación:
Reino Unido