Negative feedback of miR-29 family TET1 involves in hepatocellular cancer.

Primary hepatocellular carcinoma (HCC) is the most common form of liver cancer and is one of the most common malignancies worldwide. Tumor suppressor gene silencing through DNA methylation contributes to cancer formation. The ten-eleven translocations (TET) family of α-ketogluta-rate-dependent dioxygenases catalyzes the sequential oxidation of 5-methylcytosine to 5-hydroxymethyl-cytosine, 5-formylcytosine and 5-carboxylcytosine, leading to eventual DNA demethylation. MicroRNAs are an abundant class of 17-25 nucleotides small noncoding RNAs, identified as important regulators of many diverse biological processes. In this study, we showed that TET1 expression was obviously reduced in the majority of examined HCC tissues. And we further investigated the expression and functional involvement of TET1 in proliferation, migration and invasion, and determined that TET1 may function as a tumor suppressor. MiR-29b was proved to inhibit metastasis through the targeting of TET1, indicating that downregulation of miR-29 may involve in HCC carcinogenesis and progression through potentiation of TET1 expression. Thus, we elucidated the roles of feedback of miR-29-TET1 downregulation in HCC development and suggested a potential target in identification of the prognosis and application of cancer therapy for HCC patients.