[Cellular mechanisms of induction of apoptosis in human erythroleukaemic K562 cells line treated by quinoline-N-oxide derivatives].

We have studied the influence of 2-(4'-nitrostyryl)-quinoline-1-oxide (2-NSQO) and 4-(4'-nitrostyryl)-quinoline-1-oxide (4-NSQO) on modulation activity of microsomal NADPH-oxidoreductases, concentration of nicotinamide enzymes and induction of apoptosis in human erythroleukaemic K562 cells. It was shown, that activity of microsomal NADPH-cytochrome c-reductases in cancer cells was inhibited by 10 microM 4-NSQO (15%), and 10 microM 2-NSQO (50%). Treatment of cells with these reagents for two days, was accompanied by caspases-9 and -3 activation, rise of EtBr and DAPI fluorescence related to DNA binding and induction of apoptosis. Apoptosis was preceded by the decrease of concentration of nicotinamide enzymes. Thus 4-NSQO is a promising compound for further experimental trials as an anticancer drug with low toxic action on the tissues of organism.