LncRNA STK4 antisense RNA 1(STK4-AS1) affects the osteosarcoma cell cycle by regulating p53 protein

Abstract

Background: LncRNA STK4-AS1 has been identified as a potential biomarker associated with multiple cancers. We proposed that STK4-AS1 plays a role in the proliferation of osteosarcoma by regulating its cell cycle. Methods: We compared the expression of STK4-AS1 in osteosarcoma vs normal samples both in clinical tissues and cell lines. We overexpressed and knockdown STK4-AS1 in p53 expressing osteosarcoma cells U2OS and p53 muted expressing osteosarcoma cells MG63 and analyzed cell viability and cell cycle. We overexpressed p53 in STK4-AS1 knockdown cells to explore the association of STK4-AS1 and p53 in the cell cycle. Results: The STK4-AS1 expression was higher in osteosarcoma tissue than adjacent normal bone tissues and was higher in osteosarcoma cell lines (U2OS, MG63, and SAOS-2) than in osteoblast cell lines (hFOB and HOB). Knockdown of STK4-AS1 in U2OS decreased the cell viability, increased cells in the G0/G1 phase, decreased cells in the S and G2/M phase, decreased expression of cyclin A and B, increased p53 and p21, and had no effect on cyclin D and cyclin E, while overexpression did the opposes. MG63 cell viability was not affected by altered STK4-AS1 levels. P53 overexpression in STK4-AS1 knockdown cells recovered cell viability, p21, cyclin A, and cyclin B expression. Conclusion: LncRNA STK4-AS1 affected p53 expressing osteosarcoma cells U2OS cell viability through regulating cell cycle, which is mediated by p53/p21 pathway.