Regulatory role of long-chain non-coding RNA HIF1A-AS1 on hypoxia-induced the autophagy of pancreatic cancer PANC1 cells

Abstract

Objective To observe the regulatory role of long non-coding RNA HIF1A-AS1 on the autophagy of pancreatic cancer PANC1 cells induced by hypoxia. Methods The pancreatic cancer PANC1 cells were cultured in a three-gas incubator filled with hypoxic gas mixture (94% N2, 5% CO2, 1% O2) for 3, 6, 12, 24, 36 and 48 h. HIF1A-AS1 overexpression and low expression PANC1 cells were obtained by the infection of recombinant adenovirus carrying HIF1A-AS1 and the transfection of HIF1A-AS1 targeting siRNA by liposome, and routinely cultured PANC1 cells served as control. The expression of HIF1A-AS1 of PANC1 cells was detected by real-time quantitative PCR after being cultured in hypoxia-induced condition for 24 h. The apoptosis rate was detected by flow cytometry. The autophagy related proteins Beclin 1 were detected by western blot. Results The expression of HIF1A-AS1 in hypoxic cells was increased as the hypoxic time increased since 6 h and peaked at 36 h, which was significantly higher than that in control group (P<0.01). HIF1A-AS1 relative expression in HIF1A-AS1 overexpression and low expression PANC1 cells was 4.49±0.53 and 0.49±0.07, which were normalized to that of control group with the relative expression of 1. Control group had lower HIF1A-AS1 expression than HIF1A-AS1 overexpression PANC1 cells but higher HIF1A-AS1 in HIF1A-AS1 low expression PANC1 cells, and the differences were statistically significant (P<0.01). The cell apoptosis rate of control, HIF1A-AS1 overexpression and low expression PANC1 cells was (8.27±1.28)%, (6.56±1.49)% and (19.9±2.34)% after 24 h hypoxic culture. Control group had higher HIF1A-AS1 expression than HIF1A-AS1 overexpression PANC1 cells but lower HIF1A-AS1 in HIF1A-AS1 low expression PANC1 cells, and the differences were statistically significant (P<0.01). The expression of Beclin 1 protein was protein 1.05±0.11, 1.29±0.19 and 0.38±0.18, respectively. Control group had lower Beclin 1 expression than HIF1A-AS1 overexpression PANC1 cells but higher Beclin 1 in HIF1A-AS1 low expression PANC1 cells, and the differences were statistically significant (P<0.01). Conclusions HIF1A-AS1 can promote autophagy of pancreatic cancer PANC1 cells induced by hypoxia and participate in the pathogenesis and metastasis of pancreatic cancer. Key words: Pancreas; Cell line, tumor; Long non-coding RNA; HIF1A-AS1; Autophagy; Anoxia