Effect On Apoptosis Induction Of Genistein On K562 And K562/ADM Cells

Objective :To study the growth inhibition and apoptosis induction effects of genistein on human leukemia cells and its apoptosis induction mechanisms. Methods:Growth inhibition effects of genistein on K562 and K562/ADM cells were investigated by MTT colorimetry. Morphological changes of K562 cells treated with genistein by Wright-Gimesa. DNA ladder was examined Agarose gel electrophoresis. Genistein induced apoptosis and expression of bc-2 protein of the two cell lines was detected by flow cytometry. Bcl-2 protein and bax protein expression was observed by immunocytochemistry. Results:Genistein could powerful inhibit cell growth of both K562 and K562/ADM cell lines, And inhibition of K562 and K562/ADM cell lines was direct proportion concertration by treated with genistein, drug resistance of K562/ADM cell was 1.67 multiple. K562 cells appeared typical apoptotic morphological changes treated with concentration increasing of genistem by microscope when compared with control group . K562 cells showed typical DNA ladder treated with 50-100μmol/L of genistein for 48 h by Agarose gel electrophoresis. The same concertration genistein induced less apoptosis in K562/ADM cells than it did in K562 cells, but during G2/M of cell cycle in both K562 and K562/ADM cell lines were obvious held up. Genistein could decrease positive rate and mean fluorescent intensity of Bcl-2 protein with concertration increasing, but not K562/ADM cells was. Bax protein was significantly expressed (positive rate: 100 %) in K562 cells treated with different concentrations of genistein when compared with control croup (P<0.05), however, Bcl-2 protein expression had no .significant differencebetween experimental and control groups. In K562/ADM cells, Bcl-2 protein was highly expressed, but the expression of Bcl-2 protein and Bax protein had no significant difference between experimental and control groups (P>0.05). Conclusion:Genistein could powerful inhibit cell growth of both K562 and K562/ADM cell lines, drug resistance of K562/ADM cells was 1.67 multiple, it showed K562/ADM cells was multidrug resistance cell line, Genistein made a much sensitive reaction in K562 cells than it did in K562/ADM cells, during G2/M of cell cycle in both K562 and K562/ADM cell lines were obvious held up by genistein. The same concertration genistein induced less apoptosis in K562/ADM cells than it did in K562 cells, it was indicated that K562 cell lines was inclined to apoptosis to genistein. Genistein induced high expression of Bax protein and low expression of Bcl-2 protein may be one of its apoptosis induction mechanisms in K562 cells, drug resistance and apoptosis restrained of K562/ADM cells are related with high expression of Bcl-2 protein,it is may be relevant to have still more expression of Bcl-2 protein and not easy to drop on multidrug resistance cell.