Study On Epigenetic Change Of CHD5Gene In Esophageal Cancer

Background:Esophageal cancer ranks as the8th most common cancer worldwide. The incidence of esophageal cancer increased rapidly in the past twenty years and about380,000cases died each year. However, the mechanisms contributing to carcinogenesis of esophageal cancer are still poorly understood. Recent studies showed that aberrant promoter DNA methylation contributes to gene silencing, may participate in the carcinogenesis of human cancer.Chromodomain helicase DNA-binding protein5(CHD5) is a member of chromodomain. It was been discovered as a novel tumor suppressor gene in2003. Promoter region methylation is related to loss of CHD5expression has been found in many human cancer. However, CHD5epigenetic changes in esophageal cancer remains unclear.Objective:To explore epigenetic changes of CHD5during esophageal squamous cell carcinoma and the possibility of CHD5promoter region methylation as human esophageal cancer marker. Method:Methylation-specific polymerase chain reaction (MSP) was used to detect the methylation status of CHD5in72cases esophageal squamous cell carcinoma and matched adjacent tissue, nine cases normal mucosa, and four esophageal cancer cell linesKYSE70, KYSE140, SKGT4and YES2. Reverse transcription polymerase chain reaction (RT-PCR) was performed to detect the expression of CHD5in esophageal cancer cell lines mentioned above. In this topic we use SPSS17.0statistical software package for statistical analysis, and the significant test standard was a=0.05.Results:69%(50/72) cases of esophageal squamous cell carcinoma were methylated, and32%(23/72)cases were methylated in matched adjacent tissue(x2=20.254, P<0.05). Nine cases of normal esophageal mucosa were unmethylated. Loss of CHD5expression was found in2esophageal cancer cell lines KYSE70and SKGT4with promoter region methylation, and after treatment with5-aza-dc for96h, the CHD5was re-expression.Conclusion:CHD5is frequently methylated in esophageal squamous cell carcinoma; The mRNA of CHD5is regulated by DNA methylatuion in esophageal cancer, epigenetic change may be an important regulation mechanism of its expression and transcription.