HIF-1α基因表达下调对人结肠癌SW480细胞增殖和VEGF表达的影响

Effects of HIF-1α gene knock-down on proliferation of and VEGF expression in human colon carcinoma SW480 cells

目的:研究转录因子-缺氧诱导因子-1α(HIF-1α)在缺氧条件下对人结肠癌SW480细胞增殖的作用,以及HIF-1α对血管内皮生长因子(VEGF)表达的影响,研究HIF-1α调节SW480细胞增殖的机制.方法:构建针对HIF-1α的pSu-per-EGFPsiRNA表达载体,转染SW480细胞,抑制HIF-1α的表达,RT-PCR和WesternBlot检测抑制结果;MTT法检测HIF-1α被抑制后,SW480在缺氧培养条件下的增殖情况;RT-PCR和WesternBlot检测VEGF的表达.结果:缺氧培养条件下,HIF-1α和VEGF表达明显上升;转染pSuper-EGFPsiRNA表达载体后,SW480细胞HIF-1αmRNA和蛋白质的表达大幅下降;SW480细胞增殖下降(P<0.05);而在缺氧培养条件下有较高表达的VEGF,其mRNA和蛋白质的表达也大幅下降.结论:HIF-1α在缺氧条件下,对SW480细胞在增殖有影响,其机制可能是通过在缺氧时上调节VEGF等细胞生长因子的表达,进而调节肿瘤细胞生长.

AIM： To investigate the effect of hypoxia-inducible transcription factor-1α （HIF-1α） on proliferation of and the VEGF expression in SW480 cells, so as to explore the possible mechanism of HIF-1α regulation on cell proliferation. METHODS： The pSuper-EGFP siRNA expression vector targeting HIF-1α was constructed, transferred into SW480 ceils, and then exposed to a normoxic or hypoxic environment, mRNA and protein levels of VEGF were respectively detected by RT-PCR and Western Blot in different ceil culture environment. MTY assay was adopted to detect SW480 cell proliferation after HIF-1α was inhibited. RESULTS： The mRNA and protein expression of HIF-1α was inhibited by HIF-1α siRNA vector. The mRNA and protein level of VEGF decreased obviously by HIF-1αgene silence. The SW480 ceil proliferation was also down regulated with HIF-1α inhibition （ P 〈 0.05 ）. CONCLUSION ： The expression of VEGF is down-regulated via HIF-1α gene silence, thus inhibiting the proliferation of SW480 cells. HIF-1α is a good target gene in anticancer therapy for colon tumors.