Effects of hypoxia inducible factor-1 alpha-targeting small interfering RNA on vascular endothelial growth factor gene expression in HaCaT cells

Objective To observe the effects of hypoxia inducible factor-1 alpha (HIF-1α)-targeting small interfering RNA (siRNA) on the expression of HIF-1α and vascular endothelial growth factor (VEGF) in HaCaT ceils under hypoxic conditions. Methods HaCaT cells were cultured and divided into four groups, normal control group (without any treatment), hypoxia group (cultured under hypoxic conditions for 24 hours),liposome control group (transfected with liposome followed by hypoxic culture for 24 hours), RNA interference group (transfected with HIF-1α-targeting siRNA/liposome complexes followed by hypoxic culture for 24 hours). Fluorescence real-time quantitative PCR was utilized to determine HIF-1oα and VEGF mRNA expression in HaCaT cells, and Western blot to detect HIF-1α and VEGF protein expression. Results No significant difference was observed in the mRNA expression of HIF-1α between the hypoxia group and normal control group (0.907 ± 0.032 vs. 0.878 ± 0.034, F =1.108, P ＞ 0.05), while the expression levels of VEGF mRNA,HIF-1α and VEGF proteins were significantly higher in the hypoxia group than in the normal control group (0.935 ± 0.032 vs. 0.652 ± 0.053, 0.813 ± 0.047 vs. 0.236 ± 0.014, 0.791 ± 0.030 vs. 0.316 ± 0.013, all P ＜0.05). A significant decline was noted in the mRNA and protein expression levels of VEGF (0.230 ± 0.044 vs.0.978 ± 0.030, 0.213 ± 0.026 vs. 0.817 ± 0.049, both P ＜ 0.05) and HIF-1α (0.497 ± 0.033 vs. 0.806 ±0.040, 0.249 ± 0.028 vs. 0.833 ± 0.052, both P ＜ 0.05) in the RNA interference group than in the liposome control group. Conclusions Hypoxia may enhance the expression of HIF-1α and VEGF in HaCaT cells, and to inhibit the HIF-1α expression may suppress the expression of VEGF in HaCaT cells under hypoxia. Key words: Keratinocytes;  Hypoxia-inducible factor, alpha subunit;  RNA interference;  Vascular endothelial growth factors