Effects of silencing hypoxia inducible factor-1α gene on expression of vascular endothelial growth factor and glucose transporter-1 of human bladder cancer cell line BIU-87

Abstract

Objective To investigate the effects of silencing hypoixa inducible factor-1α (HIF-1α)gene by RNA interference (RNAi) on the expression of vascular endothelial growth factor (VEGF) and glucose Transporter-1 (GLUT-1) of human bladder cancer cell line BIU-87.Methods BIU-87 cells were cultured in vitro.The expression of HIF-1α,VEGF and GLUT-1 was detected by using fluorescence real-time quantitative polymerase chain reaction (PCR) and Western blotting under normoxia or hypoxia (90％ N2 +5％ H2 +5％ CO2).Transfection efficacy of HIF-1α-siRNA was detected by using Western blotting.The cell proliferation was tested by SRB assay after transfection of HIF-1α-siRNA.The expression of HIF-1α,VEGF and GLUT-1 was detected.Results HIF-1α protein (0.56 ± 0.08,1.33 ± 0.21),VEGF mRNA (2.12±0.29,3.27 ±0.46),VEGF protein (0.29 ±0.04,0.59 ±0.10),GLUT-1 mRNA (1.99 ±0.22,3.95 ±0.48),and GLUT-1 protein (0.38 ±0.05,0.65 ±0.11) were increased under hypoxia for 8 and 24 h as compared with those under the normoxia [HIF-1α protein (0.33 ± 0.05),VEGF mRNA (0.97 ± 0.11),VEGF protein (0.98 ± 0.16),GLUT-1 mRNA (1.05 ± 0.12),GLUT-1 protein (1.46 ± 0.24) (P ＜ 0.05)].HIF-1α mRNA under hypoxia for 8 and 24 h (1.05 ± 0.09,0.96 ± 0.11)had no significant difference from that under the normoxia (1.16 ±0.13) (P ＞0.05).HIF-1α expression was suppressed after HIF-1α-siRNA transfection.The proliferation (0.63 ± 0.08),the expression of VEGF mRNA (0.43 ± 0.05),VEGF protein (0.58 ± 0.07),GLUT-1 mRNA (0.56 ± 0.06),and GLUT-1 protein (0.51 ± 0.07) were decreased after HIF-1α-siRNA transfection as compared with those before transfection (1.12 ±0.17,1.08 ±0.12,1.19 ±0.17,1.07 ±0.18,1.16 ±0.16,P＜0.05).Conclusion HIF-1α-siRNA could inhibit proliferation of BIU-87 cells by silencing HIF-1α,and inhibiting the expression of VEGF and GLUT-1. Key words: Hypoixa inducible factor-1α; Bladder tumor; RNA interference ; Vascular endothelial growth factor; Glucose transporter-1