1. Clinical Oncology Laboratory, Changzhou Tumor Hospital, Soochow University, Changzhou, China;
2. Tumor Immunology and Gene Therapy Center, Eastern Hepatobiliary Surgery Hospital, the Second Military Medical University, Shanghai, China;
3. Department of Oncology, Nanyang Center Hospital, Nanyang, China;
4. Department of Clinical Laboratory, Shanghai East Hospital, Tongji University Medical School, Shanghai, China.
* These authors contributed equally to this work.
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.
Keywords: RECK, hepatocellular carcinoma, methylation.