[Study on DNA damage and expression of RAS gene in L-02 cells exposed to chlorinated drinking water extracts]

To study the DNA damage and expression of RAS gene in human fetal hepatocytes (L-02) induced by chlorinated drinking water extracts, and to explore the possible molecular mechanism of its genotoxicity .

L-02 cells were exposed to chlorinated drinking water extracts at the concentration of 0.167, 1.67, 16.7 and 167 ml/ml culture medium. Single cell gel electrophoresis (SCGE) and in situ hybridization (ISH) assay were used to detect DNA damage and the expression of RAS gene in L-02 cells. DMSO (10 ml/L) and B(a)P (200 micromol/L) were used as solvent control and positive control respectively.

Chlorinated drinking water extracts led to a significant increase of DNA migration in the L-02 cells at the concentrations of 16.7 and 167 ml/ml culture medium in comparison with solvent control. Significantly higher expressions of RAS gene was found in the L-02 cells exposed to all concentrations of chlorinated drinking water extracts than in that of solvent control group. There was a significant correlation (r = 0.99) between RAS gene expression and DNA migration when the concentration of chlorinated drinking water extracts was between 0.167 and 16.7 ml/ml.

Chlorinated drinking water extracts could induce obvious DNA damage and RAS gene expression in L-02 cells, and RAS gene expression might be affected by DNA damage.