Figure 2.

Differential efficiency of DNA repair in response to NDEA, NDELA and NDPA treatment. The SGC7901 cells were treated with 1X IC₅₀ concentrations of NDEA (0.76 mM), NDELA (1.09 mM) or NDPA (0.39 mM) for 1 h. The cells were then incubated in a drug-free medium for 12 h to allow DNA repair. (A) DNA damage was detected by neutral comet assays. Dox (1 mM) treatment was used as a positive control. The tail to head ratio of comet DNA in cells treated with NDELA or NDPA was reduced. (B) The 50 cells per slide from (A) were analyzed by measuring the tail to head ratio. ^*P<0.05 and ^**P<0.01, T group vs. R group. The tail to head ratio of comet DNA in cells treated with NDELA or NDPA was significantly reduced. (C) The SGC7901 cells were treated with 1X IC₅₀ concentrations of NDEA (0.76 mM), NDELA (1.09 mM) or NDPA (0.39 mM) for 1 h. The cells were then incubated in drug-free medium for 12 h. The level of γ-H2AX was determined by western blotting. The expression of γ-H2AX in SGC7901 cells treated with NDELA or NDPA was significantly reduced. NDEA, N-nitrosodiethylamine; NDELA, N-nitrosodiethanolamine; NDPA, N-nitrosodipropylamine; Dox, Doxorubicin.