Clinic Significance of Expression of bcl-2 and bax Gene in Patients with Acute Leukemia and its Relationship with mdr-1 Gene Expression

It is generally accepted that the inhibition of apoptosis is one of the mechanism of drug resistance to tumor. Members of the bcl-2 gene family are the most important regulators in apoptosis. The purpose of this study is to evaluate the value of expression of bcl-2 and bax gene in predicting the prognosis of acute leukemia patients, and to explore the relationship between bcl-2 and bax expression and drug resistance. Seventy patients with acute leukemia entered this study. Expressions of bcl-2, bax and mdr-1 gene were measured by RT-PCR method and FCM. The result showed that: bcl-2 had been widely detected in specimens of blood or bone marrow from acute leukemia patients, the expression levels were much higher than those in normal control (1.46 vs 0.71, P < 0.05), bax expression levels and bax/bcl-2 ratio in patients had no significant difference with the control. No relationships were found between the expression levels of bcl-2 and bax and AL patients' age, sex, platelet counts, hemoglobin levels, percentage of marrow blasts, FAB classification, and S + G(2)M%. Both Bcl-2 protein expression (34.6% vs 69.2%, P < 0.03) and bax/bcl-2 mRNA ratio (37.1% vs 82.9%, P < 0.01) were associated with response to therapy and CR rate, bax/bcl-2 ratio also influences the overall survival time. There was no relationship between bcl-2 and bax expression levels and mdr-1 expression levels.