Aberrant Promoter Methylation And Reversal Of Multiple Genes In Hepatocellular Carcinoma Cell Lines

Objective To study the methylation of SLIT2, DAPK, RIZ1, CHFR, EDNRB and 3-OST-2 in SUN449, BEL-7402, SMMC-7721, Hep3B and HepG2 5 hepatocellular carcinoma cell lines. Methods Methylation-specific PCR was adopted to investigate the promoter methylation of these genes in these 5 cell lines. Methylation specific PCR was utilized to examine the changes of state of methylation status of SLIT2 gene on 5 HCC ce11 line before and after the treatment with 5-Aza-CdR of different concentration. RT-PCR method was used to detect the changes of SLIT2 mRNA. Results SLIT2, RIZ1, EDNRB and 3-OST-2 was fully methylation in SUN449, BEL-7402, SMMC-7721, Hep3B and HepG2 5 HCC cell lines with the methylation rate of 100%. DAPK was fully unmethylation in the 5 cell lines. CHFR was methylation in SUN449, BEL-7402, SMMC-7721 and HepG2 with the methylation rate of 80%. Partly methylation in SUN449, SMMC-772 and HepG2 cell lines, and fully methylation in BEL-7402 cell lines but unmethylation in Hep3B cell lines were found with CHFR gene. Unmethylated product was detected and hypermethylation was reversed after treatment with 5-Aza-CdR at the concentration of 1mmol/L, 5mmol/L, 10mmol/L, 20 mmol/L, the expression level of SLIT2 mRNA increased significantly (P<0.05). Conclusions Methylation of SLIT2, RIZ1, CHFR, EDNRB and 3-OST-2 was a common event in HCC cell lines, and was occurs frequently in HCC, and might participate in the carcinogenesis and development of HCC; the methylation level of DAPK was low, It might not a major cause of HCC; hypermethylation was reversed and the expression level of SLIT2 mRNA increased significantly after treatment with 5-Aza-CdR,it provides experimental basis for demethylation treatment of HCC.