Effect of RNA Interference Targeting HIF-2α Gene on Invasion and Proliferation of Lung Adenocarcinoma A549 Cell Line

Objective:To investigate the effect of small interfering RNA(siRNA) targeting hypoxia-inducible factor 2α(HIF-2α) gene on the invasion and metastasis of A549 cell line.Methods:The siRNA eukaryotic expression vectors targeting HIF-2α gene were designed and transfected into A549 cell line.Quantitative real-time PCR(qRT-PCR) and Western blot were used to detect mRNA and protein expression of HIF-2α gene.The migration of A549 cells was assayed using transwell cell culture chambers,and vascular endothelial growth factor(VEGF) protein expression was determined by enzyme-linked immunosorbent assay(ELISA).Results: After transfection of HIF-2α-siRNA into A549,mRNA and protein expression of HIF-2α were downregulated.The results of qRT-PCR showed that No.4 siRNA vector was the most effective one in suppressing HIF-2α mRNA expression.Transfection of A549 with this siRNA vector resulted in sequence-specific silencing with decreases of(60.63±5.10)% and(80.00±3.55)% in HIF-2α mRNA transcription at 24h or 48h post-transfection.The Western blot test also demonstrated the best effectiveness of this expression vector with the inhibition rates of(31.69±11.56)% at 24h post-transfection and(82.9±4.09)% at 48h post-transfection.It was shown in migration analysis that the number of cells which had migrated through the filter was much amaller in groups treated with HIF-2α-siRNA than in control,which indicated a reduction in the invasive capacity of this group.ELISA analysis showed the protein expression of VEGF was significantly down-regulated when A549 cells were treated with siRNA targeting HIF-2α transfection.Conclusions: Eukaryotic expression vectors of siRNA which inhibit the expression of HIF-2α gene can effectively suppress the invasion and metastasis of A549 cells.