[Effects of 3β-HSD gene silence or overexpression on DEHP induced oxidative damage in MCF-7 cells]

Objective: To study the oxidative damage of di- (2-ethylhexyl) phthalate (DEHP) on MCF-7 cells, and to investigate the effects of 3β-hydroxysteroid dehydrogenase (3β-HSD) gene silence or overexpression on DEHP-induced oxidative damage. Methods: MCF-7 cells, 3β-HSD gene silencing cells and 3β-HSD gene overexpression cells were treated with different doses of DEHP (0,0.05,0.1,0.2,0.4,0.8 mmol/L) for 24h, then intracellular oxidative damage index such as MDA, SOD, GSH, GSH-PX were detected, DNA repair gene hOGG1, hMTH1 mRNA expression were tested by Q-PCR, hOGG1, hMTH1 protein expression were detected by western blot. Results: After MCF-7 cells were treated by DEHP, MDA levels increased; SOD activity, GSH content, GSH-PX activity decreased, hOGG1 and hMTH1 mRNA expression levels increased, hOGG1 and hMTH1 protein expression levels increased, the differences were statistically significant when compared with control (P<0.05 or P<0.01) . In 3β-HSD gene silencing cells which were treated by DEHP, when compared with the same dose group of MCF-7 cells, MDA content increased, SOD activity, GSH content, GSH-PX activity decreased, hOGG1 and hMTH1 mRNA expression levels decreased, hOGG1 and hMTH1 protein expression levels decreased, the difference were statistically significant (P<0.05 or P<0.01) . In 3β-HSD gene overexpression cells which were treated by DEHP, when compared with the same dose group of MCF-7 cells, MDA content decreased; SOD activity, GSH content, GSH-PX activity increased, of hOGG1 and hMTH1 mRNA expression levels increased, hOGG1 and hMTH1 protein expression levels increased, the difference were statistically significant (P<0.05 or P<0.01) . Conclusion: DEHP could cause oxidative damage in MCF-7 cells, induce the changes of related genes and proteins, 3β-HSD plays an antioxidant role in the process of DEHP ox-idative damage.