Figure 1.

NDEA, NDELA and NDPA-induced DNA double-strand breaks (DSBs). SGC-7901 cells were treated with 1X IC₅₀ concentrations of NDEA (0.76 mM), NDELA (1.09 mM) or NDPA (0.39 mM) for 15, 30 and 60 min. (A) DNA damage was determined using a neutral comet assay. Three compounds induced apparent DNA damage in SGC7901 cells. (B) The 50 cells per slide from (A) were analyzed to calculate the tail to head ratio of the SGC-7901 cells. Three compounds induced a time-dependent increase in extent of DNA damage. (C) The SGC-7901 cells were treated with 1X IC₅₀ concentrations of NDEA (0.76 mM), NDELA (1.09 mM) or NDPA (0.39 mM) for 1 h. Following treatment, the cells were stained with antibodies against γ-H2AX and counter-stained with DAPI. The cells treated with Dox (1 mM) for 1 h were used as positive controls. NOC treatment lead to formation of γ-H2AX. (D) The SGC-7901 cells were treated with 1X IC₅₀ concentrations of NDEA (0.76 mM), NDELA (1.09 mM) or NDPA (0.39 mM) for 15, 30 and 60 min. Following the treatment, the cells were collected and the cellular protein was prepared for western blotting using antibodies against γ-H2AX. Three compounds induced expression of γ-H2AX. NDEA, N-nitrosodiethylamine; NDELA, N-nitrosodiethanolamine; NDPA, N-nitrosodipropylamine; DAPI, 4′,6-diamidino-2-phenylindole; Dox, Doxorubicin.