[The clinical significance of p16 protein non-expression and p16 gene inactivation by deletions and hypermethylation in nasopharyngeal carcinoma].
Zhonghua Bing Li Xue Za Zhi
; 34(6): 358-61, 2005 Jun.
Article
em Zh
| MEDLINE
| ID: mdl-16185507
ABSTRACT
OBJECTIVE:
To investigate the clinical significance of p16 protein non-expression and p16 gene inactivation by deletions and hypermethylation in nasopharyngeal carcinoma.METHODS:
Immunohistochemical study for p16 protein was carried out in 90 cases of non-keratinizing carcinoma (NKC) of nasopharynx. P16 gene deletions and hypermethylation were also analyzed by polymerase chain reaction (PCR) and methylation-specific PCR in 23 randomly selected NKC cases.RESULTS:
Among the 90 NKC cases studied, 42 cases (46.7%) were negative for p16 protein. The non-expression rate of p16 protein also correlated with the 5-year survival rate. The non-expression rate was 60.0% in patients who died within 5 years, in contrast to 20.0% in those alive for over 5 years after diagnosis. The non-expression rate of p16 protein in cases with or without distant metastasis was 81.8% and 41.8% respectively (P < 0.05), while that in cases with or without local invasion into skull base was 41.7% and 48.5% respectively (P > 0.05). As for molecular analysis, deletion of p16 gene exon 2 was found in 10 of the 23 cases (43.4%) studied, while deletion of p16 gene exon 1 was not detected in these samples. Hypermethylation of p16 gene exon 1 was also noted in 2 of the 23 cases (8.7%). The overall mutation rate of these cases was 52.1%.CONCLUSIONS:
There is a high incidence of p16 protein non-expression, deletion of p16 gene exon 2 and hypermethylation of p16 gene exon 1 in NKC. P16 gene inactivation may thus play an important role in the pathogenesis of NKC, especially in terms of its metastatic potential.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neoplasias Nasofaríngeas
/
Deleção de Genes
/
Genes p16
/
Inibidor p16 de Quinase Dependente de Ciclina
Limite:
Humans
Idioma:
Zh
Revista:
Zhonghua Bing Li Xue Za Zhi
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
China