SOX9/MKLN1-AS Axis Induces Hepatocellular Carcinoma Proliferation and Epithelial-Mesenchymal Transition.

SOX9, as a transcript factor, has been confirmed to boost proliferation and epithelial-mesenchymal transition (EMT) of hepatocellular carcinoma (HCC), but the underlying mechanism remains incompletely elucidated. A bioinformatics analysis web, Jaspar, manifested that SOX9 can transcriptionally regulate an lncRNA, MKLN1-AS. To determine the role of MKLN1-AS in HCC, this study measured MKLN1-AS expression in HCC and the paracancerous tissues and conducted a series of assays, including MTT, colony formation, and transwell assays, in vitro. EMT of HCC was evaluated by E-cadherin and vimentin protein levels. The regulatory effect of SOX9 on MKLN1-AS was determined using dual luciferase reporter and ChIP assays. Both MKLN1-AS and SOX9 were up-regulated in HCC tissues compared to paracancerous tissues. SOX9 promoted cell viability, proliferation, invasion, and EMT of HCCs, but these promoting effects of SOX9 were attenuated after the knockdown of MKLN1-AS. Overexpression of SOX9 increased MKLN1-AS in HCCs, whereas silencing SOX9 decreased MKLN1-AS expression. According to dual luciferase reporter and ChIP assays, SOX9 can bind to the promoter of MKLN1-AS gene to stimulate the expression. MKLN1-AS is transcriptionally regulated by SOX9 and mediates the effects of SOX9 on the proliferation and EMT of HCCs.