摘要
Objective:To study the correlation between hypermethylation of the CPG island of p16 gene and its inactivation in gliomas.Mehtods:In 50 cases of brain glioma,immunohistochemical method was applied to detect the expression of p16 protein; PCR a-nalysis was performed to identify the deletion of exons 1,2 of p16 gene and hypermethylation of CPG island of exon 1 of p16 gene in brain glioma.Results:Immunohistochemical analysis showed that p16 protein expression was negative in 27 cases(54%) and positive in 23 cases(46%) of 50 cases of brain gliomas.In the group with negative p16 protein expression(n=27 cases),RT-PCR analysis showed that there were 9 cases(33%) with homozygous deletions ofp16 gene and 7 cases(26%) with hypermethylation of CPG island of p16 gene.Conclusion:The transcriptional inhibition of p16 gene may be induced by aberrant hypermethylation of p16 gene 5'-CPG island in some of the cases without the homozygous deletions of p16 gene.Hypermethylation of 5'-CPG island is one of the important mechanisms for p16 gene inactivation.
