RESUMO
OBJECTIVE@#To investigate the role of E26 transformation-specific variant 4 (ETV4) in sorafenib and cisplatin resistance in hepatocellular carcinoma (HCC).@*METHODS@#HCC cell lines SMMC-7721 and HCC-LM3 were transfected with an ETV4- overexpressing plasmid or small interfering RNAs (siRNAs) targeting ETV4. The cells with ETV4 overexpression or ETV4 interference were treated with DMSO, sorafenib (5 μmol/L) or cisplatin (5 μmol/L) for 48 h, and the total protein and total RNA were collected. Western blotting, flow cytometry, EdU proliferation assay were used to analyze the apoptosis and proliferation of the cells. We also obtained clinical specimens of HCC tissues and paired adjacent tissues from 11 patients for detecting ETV4 mRNA expression levels using real-time fluorescence quantitative PCR (q-PCR). The effect of ETV4 interference on the mRNA expression levels of immediate early response gene 3 (IER3) was examined in HCC cells that were treated with DMSO, sorafenib or cisplatin for 48 h.@*RESULTS@#The expression of ETV4 mRNA was significantly higher in HCC tissues than in the paired adjacent tissues. Overexpression of ETV4 in the HCC cell lines obviously inhibited cell apoptosis induced by sorafenib or cisplatin. Conversely, ETV4 interference significantly enhanced the apoptosis and inhibited the proliferation of the HCC cells following treatments with sorafenib or cisplatin. In addition, ETV4 regulated the mRNA expression levels of IER3 in the cells treatmed with sorafenib and cisplatin.@*CONCLUSIONS@#ETV4 promotes resistance of HCC cells to sorafenib or cisplatin .