Detection of promoter hypermethylation of p16 gene and analysis of its clinicopathological significance in human gliomas

Objective:To detect the aberrant promoter hypermethylation of p16 gene in human gliomas and analyze its clinicopathological significance.Methods:A methylation-specific PCR was performed for the detection of promoter hypermethylation of p16 gene in 42 glioma tissue samples and 42 corresponding normal brain tissue samples.The correlation between the aberrant methylation of p16 gene and the clinicopathological factors was analyzed.Results:The promoter hypermethylation ratio of p16 gene in glioma tissues(38.27%) was significantly higher than that in corresponding normal brain tissues(8.8%,P=0.000).The expression levels of p16 mRNA and protein in glioma or normal brain tissues with methylation weresignificantly lower than those with unmethylation.Moreover,we also found that the aberrant promoter methylation of p16 gene was significantly correlated with tumor stage(P=0.007),but not correlated with sex,age and tumor types of patients(P=0.669,0.869 and 0.944,respectively).Conclusion:The hypermethylation of p16 gene in CpG island is associated with downregulated p16 expression,and detection of the aberrant methylation of p16 gene promoter in human gliomas would offer an effective method for the earlier auxiliary diagnosis of this malignancy.