LncRNA DANCR promotes ATG7 expression to accelerate hepatocellular carcinoma cell proliferation and autophagy by sponging miR-222-3p.

LncRNA differentiation antagonizing non-protein coding RNA (DANCR) is an oncogene in various malignant cancers, including hepatocellular carcinoma (HCC). Autophagy is an intracellular self-digestion mechanism that accelerates the progression of HCC via promoting cell survival. However, the role of lncRNA DANCR in HCC, and the mechanism of lncRNA DANCR in the regulation of autophagy in HCC remains unknown. Therefore, the aims of this study are the investigation of the role of lncRNA DANCR in HCC, and the exploration of the molecular mechanism of lncRNA DANCR in regulating autophagy of HCC cells.In this study, the expression of lncRNA DANCR, miR-222-3p, and autophagy-related gene 7 (ATG7) was detected by qRT-PCR. The cell proliferation and colony formation were measured by Cell Counting Kit-8 (CCK-8) assay and colony formation assay. And the autophagic flux was evaluated by mRFP-GFP-LC3B reporter. The autophagy related proteins were analyzed by Western blotting. Besides, the relationship between lncRNA DANCR and miR-222-3p, as well as between miR-222-3p and ATG7, was determined by Dual-Luciferase reporter system.We found high expression of lncRNA DANCR and ATG7, and low expression of miR-222-3p in HCC tissues and cell lines. And lncRNA DANCR positively correlated with poor survival of HCC patients. Moreover, the knockdown of lncRNA DANCR inhibited cell proliferation and autophagy of HCC cells. And we predicted and proved that lncRNA DANCR induced cell proliferation, colony formation and autophagy by increasing ATG7 and suppressing miR-222-3p.Our study demonstrates the promoting role of lncRNA DANCR in HCC, and indicates the regulatory effects of lncRNA DANCR on regulating autophagy of HCC.