Abstract:

Objective   To study the clinical significance of RASSF1A methylation in the cancer tissues of patients with HCC and explore the effect of WIF-1 methylation in the genesis and development of HCC. Methods   97 cancer tissue samples of patients with hepatocellular carcinoma (HCC group) and 26 samples of adjacent liver cirrhosis (cirrhosis group) were studied. DNA extraction and sulfites methylation modification was carried out in the two groups of samples. Methylation specific PCR of these two tumor suppressor genes was run, and the methylation status was assessed subsequently. Depending on whether the patients were infected by HbsAg before operation or not, the hepatocellular carcinoma group was subdivided into the HBsAg-positive group and the HBsAg-negative group. The significance of the tumor suppressor genes RASSF1A and WIF-1 methylation was analysed. Results   The ratio of the two suppressor genes (RASSF1A and WIF-1) methylation in the HCC group(67.01% and 46.39%)was higher than that of the cirrhosis group(42.31% and 7.69%)The difference was statistically significant(P<0.05 ). There was statistically significant difference in the two genes positive methylation expression between the two groups(35.05% and 7.69%， P=0.006). Significant difference for the suppressor gene RASSF1A in the HBsAg positive and negative groups was confirmed(72.84% and 23.08%， P=0.001), but not for WIF-1 gene(44.44% and 53.84%， P=0.528). No significant difference between the tumor suppressor genes RASSF1A and WIF-1 methylation in the patients with HCC and survival rate could be found(P=0.735， P=0.229). Conclusion   The methylation ratio of the two suppressor genes (RASSF1A, WIF-1) in the cancerous tissues is higher than that in the adjacent non-cancerous cirrhosis tissues of HCC patients, which suggests that the methylation of the suppressor genes RASSF1A and WIF-1 may play an important role in HCC carcinogenesis.

Key words: Hepatocellular carcinoma； Supressor gene； RASSF1A； WIF-1； Methylation