[Correlation between DNA Methylation of ZNF772 Promoter Region and Cervical Cancer]

Objective To investigate the DNA methylation in ZNF772 promoter region and its mRNA and protein expressions and analyze the clinical significance of DNA methylation of ZNF772 gene in cervical cancer. Methods Cervical squamous cell carcinoma (SCC) tissues were harvested from three patients (SCC group),and normal cervical tissues from healthy individuals of the same age were used as the control group. Hyper-methylation and lower transcripts were screened by whole-genome bisulfite sequencing (WGBS) and RNA sequencing. Furthermore,in 40 cervical tissue samples in SCC group and 45 normal cervical tissues in the control group,DNA methylation status and mRNA expression of ZNF772 were measured by using real-time quantitative polymerase chain reaction (RT-qPCR) and bisulfite sequencing polymerase chain reaction (BSP). The protein expression was detected by immunohistochemistry. In the SCC group,the potential relationships of DNA methylation status in ZNF772 promoter and mRNA expression with the clinicopathological parameters of cervical cancer were analyzed. Results As shown by WGBS and RNA sequencing,the abnormal DNA methylated gene ZNF772 was associated with mRNA expression. RT-qPCR verified that the mRNA expression of ZNF772 was significantly lower in SCC group than in control group (t=8.351,P=0.016). Immunohistochemistry further confirmed that the positive expression of ZNF772 protein was down-regulated in SCC group (t=3.802,P=0.005). BSP showed that the DNA methylation rate of ZNF772 promoter region (-420,-422 locus) in SCC group was significantly higher than that in control group (χ ²=8.566,P=0.038;χ ²=6.332,P=0.043). Spearman correlation analysis showed that,in SCC group,DNA hypermethylation in ZNF772 promoter was negatively correlated with the mRNA expression (r=-0.351,P=0.045;r=-0.349,P=0.032) and was significantly correlated with HPV16/18 infection,tumor size,World Health Organization pathological grade,and International Federation of Gynecology and Obstetrics clinical stage (P=0.018,P=0.012,P=0.009,and P=0.035,respectively). Conclusion The DNA hypermethylation in the promoter region of ZNF772 gene is involved in the occurrence and development of cervical cancer.