Effects of TSA on promoter methylation and expression of E-cadherin gene in hepatocellular carcinoma cell lines / 中华普通外科杂志

ABSTRACT

Objective To study the effects of histone deacertylase inhibitor (TSA) on promoter methylation and expression of E-cadherin gene in a hepatocellular carcinoma cell line SMMC7721. Methods Hepatocellular carcinoma cell line SMMC-7721 was treated with TSA (300 nm/L), MTT method was used to investigate the growth inhibition ratio, TUNNL was conducted to measure the apoptosis ratio, methylation-specific PCR (MSP) was employed to detect changes in the CpG island methylation of E-cad promoter region, Western blot technique was used to detect the expression of E-cad gene and DNMT3b before and after TSA treatment, respectively. Results TSA decreases the SMMC-7721 cell viability and induces apoptosis, the growth inhibition ratio was 21.85% compared with control group. The apoptosis ratio of control group was (4.69±0.56)% ,the apoptosis ratio of TSA treatment group was (14.94±0.91)%. The apoptosis ratio of TSA treatment group was significantly higher than that of control group(P = 0.000). Before treated with TSA, the CpG island of E-cad promoter region was methylated, and the expression of E-cad was negative. TSA treatment induces demethylation of the CpG island in E-cad promoter region, causes the re-expression of E-cad. TSA reduces the expression of DNMT3b. Conclusions TSA decreases the SMMC-7721 cell viability and induces apoptosis, reverses the methylation status of E-cad promoter region, and resumes E-cad gene expression. TSA may induce demethylation through down-regulating the expression of DNMT3b.