Background & objective: Aberrant DNA methylation plays important roles during multistage carcinogenesis in various human organs. This study was to explore the relationship between the promoter methylation and inactivation of DAPK gene in cervical cancer.
Methods: The promoter methylation of DAPK was investigated with methylation-specific polymerase chain reaction (MSP) in 52 specimens of cervical cancer, 60 specimens of cervical intraepithelial neoplasia (CIN) and 20 specimens of normal cervical squamous epithelial tissues. Its correlation to clinicopathologic features of cervical cancer was analyzed. The protein expression of DAPK was detected by immunohistochemistry.
Results: The methylation rate of DAPK gene promoter was significantly higher in cervical cancer tissues than in CIN (65.4% vs. 18.3%, P<0.05); while no methylation of DAPK gene was found in normal cervical tissues. The methylation rate of DAPK gene was significantly higher in cervical squamous cell carcinomas than in adenocarcinomas (80.0% vs. 16.7%, P<0.001). Promoter methylation of DAPK was negatively correlated to its protein expression (r=-0.849, P<0.001).
Conclusion: The promoter methylation may lead to inactivation of DAPK gene, and may be related with tumorigenesis of cervical cancer.