linc-ROR facilitates hepatocellular carcinoma resistance to doxorubicin by regulating TWIST1-mediated epithelial-mesenchymal transition

Long non-coding RNAs are associated with cancer progression. Long intergenic non-protein coding RNA (linc)-regulator of reprogramming (ROR) enhances tumor development in hepatocellular carcinoma (HCC). However, the effect of chemoresistance and its underlying mechanisms in HCC are not completely understood. The present study aimed to identify the effect of ROR on sensitivity to doxorubicin (DOX) in HCC cells. In the present study, Cell Counting Kit-8 and EdU assays were performed to assess cell viability and proliferation, respectively. In addition, E-cadherin and vimentin protein expression levels were assessed via western blotting and immunofluorescence. The results of the present study demonstrated that HCC cells with high linc-ROR expression levels were more resistant to DOX, and linc-ROR knockdown increased HCC cell DOX sensitivity compared with the control group. The results indicated that compared with the NC siRNA group, linc-ROR knockdown notably suppressed epithelial-mesenchymal transition by downregulating twist family bHLH transcription factor 1 (TWIST1) expression. TWIST1 knockdown displayed a similar effect on HCC cell DOX sensitivity to linc-ROR knockdown. Moreover, linc-ROR knockdown-induced HCC cell DOX sensitivity was inhibited by TWIST1 overexpression. The present study provided evidence that linc-ROR promoted HCC resistance to DOX by inducing EMT via interacting with TWIST1. Therefore, linc-ROR might serve as a therapeutic target for reducing DOX resistance in HCC.