lncRNA A1BG‐AS1 suppresses proliferation and invasion of hepatocellular carcinoma cells by targeting miR‐216a‐5p

Abstract Extensive evidence indicate that long noncoding RNAs (lncRNAs) regulates the tumorigenesis and progression of hepatocellular carcinoma (HCC). However, the expression and biological function of lncRNA A1BG antisense RNA 1 (A1BG‐AS1) were poorly known in HCC. Here, we found the underexpression of A1BG‐AS1 in HCC via analysis of The Cancer Genome Atlas database. Further analyses confirmed that A1BG‐AS1 expression in HCC was markedly lower than that in noncancerous tissues based on our HCC cohort. Clinical association analysis revealed that low A1BG‐AS1 expression correlated with poor prognostic features, such as microvascular invasion, high tumor grade, and advanced tumor stage. Follow‐up data indicated that low A1BG‐AS1 level evidently correlated with poor clinical outcomes of HCC patients. Moreover, forced expression of A1BG‐AS1 repressed proliferation, migration, and invasion of HCC cells in vitro. Conversely, A1BG‐AS1 knockdown promoted these malignant behaviors in HepG2 cells. Mechanistically, A1BG‐AS1 functioned as a competing endogenous RNA by directly sponging miR‐216a‐5p in HCC cells. Notably, miR‐216a‐5p restoration rescued A1BG‐AS1 attenuated proliferation, migration and invasion of HCCLM3 cells. A1BG‐AS1 positively regulated the levels of phosphatase and tensin homolog and SMAD family member 7, which were reduced by miR‐216a‐5p in HCC cells. Altogether, we conclude that A1BG‐AS1 exerts a tumor suppressive role in HCC progression.