Human cell line exhibits arsenic tolerance by long-term low level arsenic-exposure

Objective: To cultivate human arsenic-resistance cell line,which will found a basis for researching arsenic-resistance genes. Methods: Human umbilical vein endothelial cells [HUVECs, ECV (304)] were exposed to low-level NaAsO₂ for 12 weeks. Parallel cultures grown in Medium without arsenic provided passage-matched control. 3-[4,5-dimethy lthiazol-2-yl]-2,5-diphenyl tetrazolium (MTT) was used to detect the survival rates and LD50 of arsenic-exposed cells and the controls, which reflected the change of arsenic tolerance. Results: In the first two weeks there was no obvious difference of LD50 between test and control groups, but 12 weeks later, cells continuously exposed to low level sodium arsenite exhibited dramatic resistance to acute arsenite toxicity. LD50 for acute arsenite exposure in these chronic arsenic-exposed ECV (304) cells was 14.3 μmol/L versus 3.9 μmol/L in control cells. Conclusions: Like other organisms,human being cell line also exhibits arsenic-resistance induced by long-term low-level arsenic.