Effect of bortezomib on proliferation, apoptosis and expression of bcl-2 family proteins in primary acute leukemia cells from elderly patients

Objective To study the anti-tumor effect and mechanism of bortezomib in primary acute leukemia cells from elderly patients.Methods Primary acute leukemia cells were treated with bortezomib 50-5000 nmol/L for 24-48 h,cell proliferation was analysed by MTT assay; apoptosis of primary acute leukemia cells was observed by fluorescence microscopy and flow cytometry; protein expression of bcl-2 and Bax was detected by Western blot.Results The cell viability was 90 ％ and 70 ％ when leukemia cells were treated with 50 and 5000 nmol/L bortezomib for 24 h,respectively.Meanwhile,cells showed (10.2±2.3) ％ and (13.3±3.3) ％ apoptosis.With prolonged treatment for 48 h,cell viability decreased to 86 ％ and 60 ％,respectively,while the apoptosis rates were increased to(18.4±3.9) ％ and(20.7±3.7) ％.Compared to the control group 0 nmol/L bortezomib,the differences were statistically significant (F =53.76,F =7.74,F =54.49,F =16.94,all P values ＜ 0.05).With the increase of bortezomib concentration,the bcl-2 protein expression was decreased,while Bax was up-regulated.Conclusion Bortezomib can inhibit primary leukemia cells from elderly patients proliferation and induce apoptosis.The mechanism may be associated with the changes in bcl-2 family protein expression. Key words: Leukemia;  Aged;  Bortezomib;  Cell proliferation;  Cell apoptosis