APOPTOSIS AND EXPRESSION OF bcl-2 and bax alpha PROTEINS IN ACUTE LEUKEMIA CELLS

Objective To study the correlation of the cell apoptotic rate and the levels of bcl 2 and bax alpha expression in leukemia patients.Methods The patients were divided into two groups:10 cases with chemo resistant leukemie(refractory or relapsed leukemia) and 10 cases with chemosensitive leukemia (primary treated sensitive leukemia). Apoptotic reates of leukemia cells of both groups were detected by flow cytometry DNA quntitative assay with PⅠ staine, which were induced with Daunorubicin (DNR 500 mg/ml).Multiparameter flow cyto metry measured the percentages and intensities of bcl2 and bax alpha expression of leukemia cells of both groups.Results The daunorubicin induced apoptotic rates were significantly different between chemosensitive and chemoresistant groups ( P =0 001). The apoptosis of chemoresistant leukemia cells had correlation with percentage of bcl 2 positive cells (r=-0 647, P =0 043) and with percentage and level of bax alpha expression (r=0 883, P =0 001;r=0 814, P =0 04),and also with bcl 2/bax alpha ratio(r=0 893, P =0 001) The apoptosis of chemosensitive cells was correlated with the positive percentage and level of bax alpha expression (r=0 653 P =0 041; r=0 762, P =0 010), and with the bcl 2:bax alpha ratio (r=0 741, P =0 014).Conclusion The chemoresponse of both drug resistant group and drug sensitive groups of leukemia patients is associated with the apoptosis of leukemia cells induced by DNR which correlated with the bcl 2:bax alpha ratio,especially with the bax alpha expression.