CpG island methylation of TMS1/ASC and CASP8 genes in cervical cancer

BACKGROUND Gene silencing associated with aberrant methylation of promoter region CpG islands is an acquired epigenetic alteration that serves as an alternative to genetic defects in the inactivation of tumor suppressor and other genes in human cancers. AIMS This study describes the methylation status of TMS1/ASC and CASP8 genes in cervical cancer. We also examined the prevalence of TMS1/ASC and CASP8 genes methylation in cervical cancer tissue and none--neo plastic samples in an effort to correlate with smoking habit and clinicopathological features. METHOD Target DNA was modified by sodium bisulfite, converting all unmethylated, but not methylated, cytosines to uracil, and subsequently amplified by Methylation Specific (MS) PCR with primers specific for methylated versus unmethylated DNA. The PCR product was detected by gel electrophoresis and combined with the clinical records of patients. RESULTS The methylation pattern of the TMS1/ASC and CASP8 genes in specimens of cervical cancer and adjacent normal tissues were detected (5/80 (6.2%), 3/80 (3.75%)-2/80 (2.5%), 1/80 (1.2%) respectively). No statistical differences were seen in the extent of differentiation, invasion, pathological type and smoking habit between the methylated and unmethylated tissues (P > 0.05). CONCLUSION The present study conclude that the frequency of TMS1/ASC and CASP8 genes methylation in cervical cancer are rare (< 6%), and have no any critical role in development of cervical cancer.