LncRNA CRNDE decreases the sensitivity of sorafenib in HCC cells via promoting ATG4B-mediated autophagy
Abstract Background: Autophagy has been confirmed to be closely related to the growth and drug resistance of cancer cells, and autophagy related 4B (ATG4B) performs a crucial role in the process of autophagy. lncRNA CRNDE (colorectal neoplasia differentially expressed) promotes the growth of hepatocellular carcinoma (HCC) cells, but it is unclear whether the tumor-promoting effect of CRNDE is associated with the regulation of ATG4B and autophagy. Methods: The expression of CRNDE and ATG4B in HCC tissues and cells was detected by quantitative real-time PCR (qPCR) and Western blot. The effect of CRNDE on autophagy of HCC cells was examined by fluorescent assay, GFP-LC3 analysis and Western blot. The relationship among CRNDE, miR-543 and ATG4B was clarified using bioinformatic analysis, qPCR, Western blot and dual-luciferase reporter assay. The effect of CRNDE on sensitivity of sorafenib in HCC cells was evaluated in vitro and in vivo by CCK-8 assay, Western blot, Hoechst staining, flow cytometry, IHC staining and TUNEL assay. Results: CRNDE induced autophagy via upregulating ATG4B in HCC cells. Mechanistically, CRNDE enhanced the stability of ATG4B mRNA by suppressing miR-543, leading to the increase of ATG4B expression and autophagy in HCC cells. Moreover, sorafenib dramatically elevated CRNDE and ATG4B as well as autophagy. Knockdown of CRNDE significantly sensitized HCC cells to sorafenib in vitro and in vivo . Conclusion: The study has revealed the presence of “CRNDE/ATG4B/autophagy” pathway which alleviates the sensitivity of sorafenib in HCC cells, suggesting that this pathway may serve as a novel target to improve the killing effect of sorafenib in HCC treatment.