目的分别构建稳定表达细胞色素P450家族2亚家族A成员13(cytochrome P450 family 2 subfamily A member 13,CYP2A13)的Flp-In CHO细胞系(CYP2A13-CHO)和稳定表达CYP2A13和细胞色素P450氧化还原酶(POR)的Flp-In CHO细胞系(CYP2A13-POR-CH...目的分别构建稳定表达细胞色素P450家族2亚家族A成员13(cytochrome P450 family 2 subfamily A member 13,CYP2A13)的Flp-In CHO细胞系(CYP2A13-CHO)和稳定表达CYP2A13和细胞色素P450氧化还原酶(POR)的Flp-In CHO细胞系(CYP2A13-POR-CHO),并从中筛选代谢活性较好的细胞系。方法课题组前期通过慢病毒转染构建了稳定表达POR的Flp-In CHO细胞系(POR-Flp-In CHO)。该文构建了pcDNA5/FRT-CYP2A13重组质粒,利用Lipofectamine^(TM) 2000转染试剂将pcDNA5/FRT-CYP2A13重组质粒分别转染到Flp-In CHO细胞和POR-Flp-In CHO细胞中。通过荧光定量PCR(qRT-PCR)、Western blot和黄曲霉素B1(AFB1)/4-甲基亚硝胺-1-3-吡啶基-1-丁酮(NNK)细胞毒实验来检测CYP2A13的表达及其活性,并比较了CYP2A13-CHO和CYP2A13-POR-CHO两种重组细胞系的代谢活性。结果与未转染的细胞相比,CYP2A13-CHO和CYP2A13-POR-CHO的CYP2A13 mRNA和蛋白的表达量均明显增加。且与CYP2A13-POR-CHO相比,CYP2A13-CHO细胞对AFB1、NNK的敏感度更高。结论建立了稳定表达CYP2A13且代谢活性较好的CYP2A13-CHO细胞系,为后续筛选能被CYP2A13代谢活化的前致癌物提供了工具。展开更多
Objective： To investigate whether CYP2E1 is responsible for the acrylamide metabolic activation in FIp-In CHO cell system. Methods： CYP2E1 cDNA was subcloned from the human liver full-length cDNA library and subsequ...Objective： To investigate whether CYP2E1 is responsible for the acrylamide metabolic activation in FIp-In CHO cell system. Methods： CYP2E1 cDNA was subcloned from the human liver full-length cDNA library and subsequently transfected into the FIp-In CHO cells to generate the stable transfectant of CYP2E1. The CYP2E1 mRNA expression was determined by RT-PCR. Acrylamide and its epoxide glycidamide induced cytotoxicity and cell cycle arrest in G2/M were conducted using MTS assay and flow cytometry, respectively. Results： In the CHO cell stably expressing CYP2E1 （CHO-2E1）, a -1.5 kb size of band was detected from the mRNA in the cells while no corresponding band in the CHO-vector cells, which indicated that CYP2E1 was successfully transfected in the CHO cells. Compared with the CHO-vector cells, acrylamide showed a concentration dependent loss of viability in the CHO-2E1 cells but no significant change of G2/M arrest was found. As expected, glycidamide induced similar profile of cytotoxicity in both of the cells, and G2/M arrest presented a concentration-dependent increased in the CHO-2E1 cells. Conclusion： The result suggested that CYP2E1 might be responsible for the acrylamide metabolism, and its metabolite glycidamide was a direct cytotoxic and genotoxic agent. It should be further considered whether acrylamide-induced toxicity is through its epoxide glycidamide in the presence of CYP2E1.展开更多
文摘Objective： To investigate whether CYP2E1 is responsible for the acrylamide metabolic activation in FIp-In CHO cell system. Methods： CYP2E1 cDNA was subcloned from the human liver full-length cDNA library and subsequently transfected into the FIp-In CHO cells to generate the stable transfectant of CYP2E1. The CYP2E1 mRNA expression was determined by RT-PCR. Acrylamide and its epoxide glycidamide induced cytotoxicity and cell cycle arrest in G2/M were conducted using MTS assay and flow cytometry, respectively. Results： In the CHO cell stably expressing CYP2E1 （CHO-2E1）, a -1.5 kb size of band was detected from the mRNA in the cells while no corresponding band in the CHO-vector cells, which indicated that CYP2E1 was successfully transfected in the CHO cells. Compared with the CHO-vector cells, acrylamide showed a concentration dependent loss of viability in the CHO-2E1 cells but no significant change of G2/M arrest was found. As expected, glycidamide induced similar profile of cytotoxicity in both of the cells, and G2/M arrest presented a concentration-dependent increased in the CHO-2E1 cells. Conclusion： The result suggested that CYP2E1 might be responsible for the acrylamide metabolism, and its metabolite glycidamide was a direct cytotoxic and genotoxic agent. It should be further considered whether acrylamide-induced toxicity is through its epoxide glycidamide in the presence of CYP2E1.
