[The relationship between microRNA-18 and BTG2 in the carcinogenesis of hepatocellular carcinoma].

OBJECTIVE: To study the difference of microRNA expression between HepG2 cells and L02 cells, and to identify the target genes of microRNA-18 (miR-18). METHODS: The differentially expressed miRNAs between HepG2 cells and L02 cells were identified by miRNA chip. Target genes of miR-18 were predicted bioinformatically. Furthermore, the expression of B-cell translocation gene 2 (BTG2), a putative target gene of miR-18, was analyzed in hepatocellular carcinoma tissues and the surrounding non-cancerous tissues by RT-PCR and northern blot. RESULTS: miR-18 was over-expressed in HepG2 cells compared to L02 cells. Altogether 609 genes, including genes involved in cell proliferation, differentiation, apoptosis and transcriptional regulation, are identified as putative miR-18 targets. The mRNA level of BTG2 was much lower in hepatocellular carcinoma tissues than in the corresponding non-cancerous tissues. CONCLUSION: miR-18 is over-expressed in HepG2 cells compared to L02 cells, and it may negatively regulate the expression of BTG2, a tumor suppressor gene.