摘要目的 探讨去乙酰化转移酶抑制剂TSA对人肝癌SMMC-7721细胞株E-cadherin基因(E-cad)启动子区甲基化及其表达的影响.方法 TSA(300 nm/L)处理人肝癌SMMC-7721细胞,MTT法、TUNEL染色法分别检测细胞生长抑制及凋亡情况,甲基化特异性的PCR(methylation-specificPCR,MSP)检测处理前后E-cad启动子区CpG岛甲基化状态;Western blot检测处理前后E-cad及DNMT3b表达水平的变化.结果 TSA能抑制人肝癌SMMC-7721细胞生长并诱导其发生凋亡,与对照组相比,实验组细胞生长抑制率为21.85%,对照组细胞凋亡率为(4.69±0.56)%,实验组凋亡率为(14.94±0.91)%,与对照组相比,凋亡细胞明显增多(P=0.000).用药前E-cad启动子区CpG岛为甲基化状态,E-cad蛋白表达阴性.TSA处理后E-cad启动子区CpG岛发牛脱甲基化,E-cad蛋白恢复表达.TSA亦导致DNMT3b的表达水平降低. 结论去乙酰化转移酶抑制剂TSA能抑制人肝癌SMMC-7721细胞生长,并可诱导其发生凋亡,逆转E-cad基因启动子区的甲基化状态,并恢复该基因表达.TSA有可能通过DNMT3b发挥脱甲基化作用.

abstractsObjective 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.