Upregulation of lncRNA PTOV1-AS1 in hepatocellular carcinoma contributes to disease progression and sorafenib resistance through regulating miR-505.

Increasing evidence has displayed the vital influence of lncRNA in tumorigenesis and chemoresistance of cancer treatment. This study investigated the function of lncRNA PTOV1-AS1 in hepatocellular carcinoma (HCC) and its role in sorafenib resistance. The relative expression of lncRNA and miRNA was measured by RT-qPCR. The cellular activities including cell proliferation and invasion were explored by CCK-8 and Transwell assays. Bioinformatics analysis and dual-luciferase reporter assay were used to predict the targeting miRNA of PTOV1-AS1. The expression levels of PTOV1-AS1 were higher in HCC tissues than that in the normal tissues and associated with patients' overall survival. Knockdown of PTOV1-AS1 decreased cell proliferation rate and invasion number. After treatment with different concentrations of sorafenib, the sorafenib-resistant hepatoma cells were conducted. PTOV1-AS1 expression levels were increased in HepG2-SR and Huh7-SR cells. PTOV1-AS1 knockdown repressed the proliferation, invasion, and drug resistance of sorafenib-resistant HCC cells by targeting the expression of miR-505. In conclusion, the expression of PTOV1-AS1 is increased in HCC and sorafenib-resistance HCC cells, as well as is associated with patients' prognosis. Inhibition of PTOV1-AS1 expression can reduce the resistance of sorafenib-resistant HCC cells, which may play a role by targeting the negative regulation of miR-505 expression.