地高辛抑制HIF-1α下调宫颈癌HeLa细胞VEGF表达的研究

Research on down-regulation of VEGF expression in uterine cervix cancer HeLa cells through inhibition of HIF-1α by digoxin

目的探讨地高辛能否在低氧环境下,通过抑制HIF-1α下调宫颈癌HeLa细胞VEGF的表达。方法将HeLa细胞分为常氧组(Normoxia组)、低氧环境组(Hypoxia组)和低氧环境+地高辛组(Hypoxia+Digoxin组),在低氧环境(1%O2、5%CO2和94%N2)下,对Hypoxia+Digoxin组细胞使用地高辛干预,干预后在不同时间点(0、24、48和72 h)使用MTT法对HeLa细胞活性进行测定;在干预72 h后,使用RT-PCR法对细胞表达的VEGF和HIF-1αmRNA进行测定,使用Western blot法对细胞表达的VEGF和HIF-1α蛋白进行测定。结果在低氧环境下,地高辛干预后的不同时间,HeLa细胞活性较未干预组逐渐降低(P<0.05);在干预72 h后,细胞VEGF和HIF-1αmRNA和蛋白的表达水平较未干预细胞明显降低(P<0.05)。结论在低氧环境下,地高辛可能是通过抑制HIF-1α的表达下调HeLa细胞VEGF的表达,导致肿瘤的增殖能力降低。

Objective To investigate whether digoxin can down-regulate the VEGF expression in uterine cervix cancer HeLa cells under hypoxic conditions. Methods HeLa cells were divided into normoxia group, hypoxia group, and hypoxia plus digoxin group. Under hypoxic conditions（ 1% 02 ,5% CO2 ,and 94% N2 ）, intervention with digoxin was carried out in hypoxia plus digoxin group. After the intervention at different time points （0,24,48, and 72 h）, MTT assay was used to detect the cytoactive of HeLa cells. RT-PCR was used to detect the VEGF and HIF-1α mRNA, and Western blot was performed to analyze the expression of VEGF and HIF-1α at 72 hours after the intervention. Results Under hypoxic conditions, at different time points after the intervention with digoxin, the cytoactive of HeLa ceils decreased compared with that of the cells which did not receive the intervention（ all P 〈 0.05 ）. At 72 h after the intervention, the VEGE and HIF-1α mRNA and the protein expression of the HeLa cells significantly decreased compared with those of the cells which did not receive the intervention （ all P 〈 0.05 ）. Conclusion Under hypoxic conditions, digoxin might down-regulate the VEGF expression of HeLa ceils through the inhibition of HIF-1α expression and thus leads to the decrease of the tumor reproductive activity.