Abstract: Objective To investigate the different expression of miR-1247-5p and its CpG island methylation on gene promoter region between normal human liver cell line L-O2 and hepatocellular carcinoma cell line SMMC-7721 by the intervention of different concentration of 5-Aza-CdR. Methods Normal human liver cell line L-O2 and hepatocellular carcinoma cell line SMMC-7721 were treated with different concentrations of 5-Aza-CdR(0, 5 and 10 μmol/L), and then to exam the methylation of miR-1247-5p gene promoter region of SMMC-7721 cell line by methylation-specific PCR (methylation specific polymerase chain reaction, MSP), finally, to detect the expression of miR-1247-5p by SYBR Green qReal Time PCR. Results Compared with normal human liver cell line L-O2, the expression of miR-1247-5p in hepatic carcinoma cell line SMMC-7721 was decreased（P < 0.05） and the methylation of its gene CpG Island in promoter region was higher. The expression of miR-1247-5p was significantly raised compared with the control group (p < 0.01) and the methylation of miR-1247-5p gene CpG Island in promoter region was reduced after demethylation drug intervention. Conclusion The methylation of miR-1247-5p expression might be involved in the occurrence and development of hepatocellular carcinoma．

Key words: Key words: hepatocellular carcinoma, miR-1247-5p, methylation, 5-Aza-CdR