Expression of Bcl-2, Bcl-X_L, Bax and Bak in acute leukemia cells and its clinical significance

Purpose: To explore the relationship between expression of apoptosis-modulating proteins and chemotherapeutic efficacy in acute leukemia. Methods: Immunocytochemical method was used to detect the expression of Bcl-2, Bcl-X_L, Bax and Bak in 36 cases of acute leukemia including previously untreated/drug-sensitive group and refractory/relapse group. Results: The average positive cell rates of Bcl-2 and Bcl-X_L in refractory/relapse group were (41.68 ± 14.39)% and (35.96 ± 9.95)%, while the rates in previously untreated/drug-sensitive group were (15. 64 ± 8.51)% and (12.91 ± 8.63)%. Statistical analysis showed the average positive cell rates of Bcl-2 and Bcl-X_L in refractory/ relapse group were higher than those in previously untreated/drug-sensitive group (P<0.01). There was no significant difference in average positive cell rates of Bax and Bak between refractory/relapse group (25.28 ± 15.49)%, (15.53 ± 10.64)% and previously untreated/drug-sensitive group (21.55 ± 12.58)%, (13.23 ± 8.36)%. The Logistic regression of expression of Bcl-2, Bcl-X_L, Bax and Bak to complete remission rate (CR) of 36 cases of acute leukemia showed that Bcl-X_L was the most risk factor in reducing the CR. Conclusions: Bcl-2 and Bcl-X_L might play important roles in multi-drug resistance of acute leukemia and Bcl-X _L was more important than Bcl-2.