LncRNA HIF1A-AS2 mediates imatinib resistance by regulating autophagy in gastrointestinal stromal tumor cells.

The aim of this study was to explore the role and mechanism of long non-coding RNA (lncRNA) HIF1A antisense RNA 2 (HIF1A-AS2) in regulating imatinib (IM) resistance in gastrointestinal stromal tumor (GIST) cells under hypoxia. The expression of HIF1A-AS2 was silenced by siRNA in GIST cells. Cytotoxicity, apoptosis, and autophagy were evaluated under normoxic and hypoxic conditions. The expression levels of HIF1A-AS2, HIF1A, apoptosis-associated genes, and autophagy-associated genes were determined by qRT-PCR analysis and western blot. We found that lncRNA HIF1A-AS2 was highly expressed in GIST tissues and cells. Knockdown of HIF1A-AS2 increased the sensitivity of GIST cells to IM and increased apoptosis. Moreover, a hypoxic environment decreased the sensitivity of GIST cells to IM, and the knockdown of HIF1A-AS2 reversed this effect. Mechanistically, the knockdown of HIF1A-AS2 inhibited IM-mediated autophagy. Finally, HIF1A was found to positively regulate HIF1A-AS2 under hypoxic conditions. Collectively, these data demonstrate that hypoxia-induced HIF1A-AS2 promotes IM resistance in GIST cells by regulating autophagy.