苯并(a)芘对子宫内膜细胞中雌激素代谢相关基因的影响

Effect of benzo ( a) pyrene on estrogen metabolism-related genes in endometrial cells

目的探讨苯并(a)芘对人子宫内膜雌激素代谢相关基因作用的分子机制。方法采用人子宫内膜癌细胞株进行体外实验,研究苯并(a)芘对细胞色素P450酶的作用,以0.016、0.8、0.4、2.0、10μmol/LBP作用RL95-2细胞12h,2μmol/LBP作用RL95-2细胞6、12、24、36、48h,细胞经收集、裂解后,用Westernblot分析方法检测总细胞提取液中CYP1A1、CYP1B1和CYP3A4蛋白表达,并用表达了CYP450酶的supersomes作为阳性对照来检测方法的可靠性。结果不同剂量BP作用于RL95-2细胞12h后,CYP1A1蛋白表达明显增加,2μmol/LBP作用于RL95-2细胞不同时间后,CYP1A1随作用时间延长而逐渐增加,作用48h后到最大值,呈现良好量效和时效关系(P<0.05)。其他细胞相关蛋白CYP1B1和CYP3A4没有改变。结论苯并(a)芘可诱导CYP1A1表达增加,可能引起雌激素代谢发生改变,并进而抑制子宫内膜癌细胞的分裂增生。

Objective To study the molecular mechanism of benzo（ a） pyrene underlying the role of estrogen metabolism-related genes in human endometrial cancer cells. Methods Effect of benzo（ a） pyrene on CYP450 was studied by exposing human endometrial cancer cells （ RL95-2） to benzo（ a） pyrene at various concentrations （ 0. 016,0. 8,0. 4,2. 0 and 10 μmol/L BP） for 12 h,or to 2 μmol/L BP for 6,12,24,36 and 48 h. RL95-2 cells were harvested and cleaved. Expressions of CYP1A1,CYP1B1 and CYP3A4 proteins in RL95-2 supernatant were detected by Western blotting. Supersome in expressed CYP450 was used as a positive control to confirm the reliability of assay methods. Results The expression of CYP1A1 protein was significantly increased in RL95-2 cells 12 h after they were exposed to different concentrations of benzo（ a） pyrene or to 2 μmol/L BP for different periods of time,and reached it peak at 48 h,indicating that expression of CYP1A1 protein depends on the used dose and time of benzo（ a） pyrene. Conclusion Benzo（ a） pyrene can increase the expression of CYP1A1 in human endometrial cancer cells,cause changes in estrogen metabolism,and inhibit proliferation of human endometrial cancer ells.