三氯乙烯对CYP3A4基因缺陷肝细胞的毒性作用

Toxic effect of trichloroethylene on liver cells with CYP3A4 gene defect

目的探讨三氯乙烯对CYP3A4基因缺陷肝细胞的毒性作用。方法用不同剂量（0．0、0．4、0．8、1．6、3．2、6．4mmol／L）三氯乙烯分别染毒正常人肝细胞（L02细胞）和CYP3A4基因缺陷肝细胞，应用CCK8实验和实时荧光定量聚合酶链反应（RT-qPCR）观察细胞活力及凋亡基因与癌基因的表达。结果1．6—6．4mmol／L三氯乙烯染毒后，CYP3A4基因缺陷肝细胞的细胞活力分别为0．91＋0．06、0．89＋0．05、0．85＋0．07，明显高于L02细胞（0．80＋0．04、0．73±0．06、0．67±0．07），差异均有统计学意义（P〈0．05）。0．8～3．2mmol／L三氯乙烯组L02细胞凋亡基因caspase-3、caspase-8、caspase-9表达升高，差异均有统计学意义（P〈0．05）；0．8-3．2mmol／L三氯乙烯组L02细胞癌基因c-myc、c-fos、k-ras表达明显升高，差异均有统计学意义（P〈0．05）；与L02细胞比较，0．8—3．2mmol/L三氯乙烯组CYP3A4基因缺陷肝细胞凋亡基因caspase-3、caspase-8、caspase-9和癌基因c—myc、c-fos、k-ras的表达水平明显下降，差异均有统计学意义（P〈0．05）。结论三氯乙烯染毒对CYP3A4基因缺陷肝细胞的凋亡基因和癌基因表达有明显影响，提示CYP3A4基因缺陷在一定程度上降低了三氯乙烯对凋亡基因和癌基因的诱导作用。

Objective To investigate the toxic effect of trichloroethylene on liver cells with CYP3A4 gene defect. Methods The normal human liver cells （L02 cells） and liver cells with CYP3A4 gene defect were exposed to trichloroethylene at different doses （0.0, 0.4, 0.8, 1.6, 3.2, and 6.4 mmol/L）. CCK8 assay and RTqPCR were used to measure cell viability and changes in the expression of apoptosis genes and oncogenes. Results After being exposed to trichloroethylene at doses of 1.6, 3.2, and 6.4 mmol/L, the liver cells with CYP3A4 gene defect showed significantly higher cell viability than L02 cells （0.91±0.06/0.89±0.05/0.85±0.07 vs 0.80±0.04/0.73 ±0.06/0.67 ±0.07, P〈0.05）. The L02 cells in the 0.8-3.2 mmol/L triehloroethylene groups showed significant increases in the expression of the apoptosis genes caspase-3, caspase-8, and caspase-9 （P〈 0.05）, as well as the oncogenes c-myc, c-fos, and k-ras （P〈0.05）. Compared with the L02 cells, the cells with CYP3A 4 gene defect showed significant reductions in the expression of the apoptosis genes caspase-3, caspase- 8, and caspase-9 and the oncogenes c-myc, c-fos, and k-ras （P〈0.05）. Conclusion Triehloroethylene exposure has a less effect on the expression of apoptosis genes and oncogenes in liver cells with CYP3A4 gene defect than in normal human liver cells, suggesting that CYP3A4 gene defect reduces the inductive effect of trichloroethylene on apoptosis genes and oncogenes.