Long non-coding RNA ADAMTS9-AS1 exacerbates cell proliferation, migration, and invasion via triggering of the PI3K/AKT/mTOR pathway in hepatocellular carcinoma cells.

Although many long non-coding RNAs (lncRNAs) are modulators of biological events in hepatocellular carcinoma (HCC), the potential significance of most lncRNAs in HCC remains to be fully understood. The role of lncRNA ADAMTS9-AS1 in HCC was therefore determined. ADAMTS9-AS1 expression was higher in HCC cell lines compared to normal cells as determined by qPCR analyses. Furthermore, CCK-8, scratch wound healing, transwell migration, and invasion assays suggested that ADAMTS9-AS1 overexpression promoted the proliferation, migration, and invasion in MHCC97-H and HepG2 cells; ADAMTS9-AS1 knockdown showed the opposite results. Based on the results from GEO, the correlation between ADAMTS9-AS1 and PI3K/AKT/mTOR was identified. Thus, an association between ADAMTS9-AS1 and the PI3K/AKT/mTOR signaling pathway was further observed. To confirm the pathway protein levels, p-AKT, PIK3CB, and p-mTOR were selected. Western blot assays suggested that ADAMTS9-AS1 enhanced the expression levels of the three proteins. Because of their close relationship with PI3K/AKT/mTOR, apoptosis- or autophagy-related proteins were further investigated. ADAMTS9-AS1 expression was negatively related with LC3-II, BECN1, and pro-apoptotic Bax, whereas it was positively correlated SQSTM1 and anti-apoptotic Bcl-2 expression. Western blot results suggested that ADAMTS9-AS1 decreased ADAMTS9 expression. Our data revealed that ADAMTS9-AS1 contributed to proliferation, migration, and invasion in HCC cells, likely due to the activation of the PI3K/AKT/mTOR signaling pathway, to influence autophagy and apoptosis. These findings suggest that ADAMTS9-AS1 could serve as a molecular target in HCC treatment.