Establishment of Human Embryonic Kidney Epithelial Cell Transformation Models Induced by Chemical Carcinogens

Objective To study the application of human embryonic kidney epithelial cell(HEK) models with DNA repair gene deficiency or human oncogene over-expression in screening potential human chemical carcinogens.Methods HEK cell line with DNA repair gene deficiency was constructed by using siRNA interference technology.DNA repair capacity of these cell lines and oncogene overexpression cells(HEKR) was detected by micronucleus(MN) test.Simultaneously,these cell lines were treated by known carcinogens MNNG,NiSO4 and tumor promotor-TPA.The malignant transformed phenotypes were examined by soft agar assay and tumor formation in immunodeficient mice to compare the sensitivity between the two types of HEK cells in screening potential human chemical carcinogens.Results HEK cell lines with DNA repair gene deficiency(HEK-shERCC1,HEKshERCC2,HEK-shATM and HEK-shMLH1) were successfully established using lentivirus-mediated siRNA interference technology.The population doubling time,cell morphology and colony forming of these cell lines showed no significant difference compared with those of the control cell line.However,the micronucleus rates of HEK-shERCC2 and HEK-shATM cells were increased by 34‰ and 30‰(P 0.05)compared with those of the control cells after the treatment of 1.0 μg/ml mitomycin C(MMC).Cells treated with 2 μmol/L MNNG,400 μmol/L NiSO4 and 800 ng/ml TPA transformed at the 8th,8th and 11th week posttreatment.However,DNA repair gene deficient HEK cell lines failed to acquire transformed phenotype 20 weeks after carcinogen treatment.Conclusion The oncogene-overexpressing cell model is more sensitive than the DNA repair gene deficient cell models in the screening of human chemical carcinogens.