The Silencing of RECK Gene is Associated with Promoter Hypermethylation and Poor Survival in Hepatocellular Carcinoma

BACKGROUND To evaluate the promoter methylation status of RECK gene and mRNA expression in patients with hepatocellular carcinoma (HCC). METHODS We analyzed RECK methylation by MSP, and RECK mRNA by real-time PCR in 74 HCC. The liver cell lines (7721, Chang and Hep-G2) were treated with 5-Aza-CdR and TSA. RESULTS RECK mRNA were lower in HCC tissues (Mean (-∆Ct) = -3.29) than that in Non-Hcc tissues (Mean (-∆Ct) = -2.42). Expression of RECK was elevated in only 24 (32.43%) of the 74 HCC patients but decreased (-∆∆Ct<0) in 50 (67.57%) of the patients. RECK promoter was hypermethylated in 55.4% (41/74) of HCCs, and in only 17.6% (13/74) of Non-Hcc samples. RECK mRNA were lower in HCC patients with hypermethylation (∆MI>=0.5) (Mean (-∆∆Ct) = -1.75) than those with demethylation (∆MI<0.5) (Mean (-∆∆Ct) = 0.05), and there is a decreased tendency for RECK mRNA in HCC patients with promoter hypermethylation (p = 0.002). There was a significantly correlation found between RECK mRNA and poor survival after surgery. After treated by 5-Aza-CdR and TSA, we found that RECK mRNA induced different changes in 7721, Chang and Hep-G2 cells. And RECK demethylation also induced by epigenetic inhibitors. CONCLUSION The results suggested that the hypermethylation may lead to promoter silencing of RECK mRNA and associated with poor survival in HCC.