关键词: 葡萄糖-6-磷酸脱氢酶, 3-羟基-3-甲基戊二酸单酰A还原酶

Abstract: To study the inhibitory effects of dehydroepiandrosterone (DHEA) and its metabolites-dehydroepiandrosterone sulfate (DHEAs) on the proliferation of HepG2 and HT-29 and their mechanism.Methods HepG2 and HT-29 were incubated by DHEA or DHEAs with different concentrations (1,10,50,100 and 200 μmol•L^-1) for 8,24,48,72 h and routine culture was used as control.The inhibitory rate was detected by using MTT chromometry and BrdU assay respectively.The activities of 3-hydroxy-3-methylglutaryl coenzyme A reductase(HMGR),glucose -6-phosphate dehydrogenase (G6PD) and lactate dehydrogenase (LDH) were examined simultaneously. Results ①MTT chromometry：DHEA with different concentrations obviously inhibited the growth of HepG2 and HT-29 cells compared with control group（P<0.05）.With the concentration of 100 μmol•L^-1 and incubated for 24 h,the inhibitory effect of DHEA decreased markedly（P<0.05）,whereas there was no significant difference of inhibitory effect between DHEAs group and control group （P>0.05）.②BrdU assay：the growth of cells were significantly inhibited by DHEA with concentrations of 50,100 and 200 μmol•L^-1,especially to HepG2 cells（P<0.05).③To HepG2 cells,HMGR activity could be inhibited by DHEA,and its inhibitory rate was 62%,while the inhibitory rate on HT-29 cells was 51%,however,DHEAs had no significant effect.④The inhibitory rate on G6PD activity was 85% by DHEA with the concentration of 100 μmol•L^-1,whereas the inhibitory rate by DHEAs was about 6%.⑤DHEA and DHEAs had no significant effect on LDH activity（P>0.05）. Conclusion DHEA has strong anti-proliferative effects on both HepG2 and HT-29 cell lines and inhibitory effects on the activities of G6PD or HMGR,however,DHEAs has no obvious effect.

Key words: glucose-6-phosphate dehydrogenase, 3-hydroxy-3-methyglutaryl coenzyme A reductase