Effect of rhDCN on proliferation of leukemic cell line K562

Objective To investigate the anti-tumorigenesis function of rhDCN on the leukemia K562 cells in vitro and analyze the possible mechanism. Methods Exponential phase of K562 cells were transfected with pcDNA3.1(+)-DCN,and PBS,liposome alone,and pcDNA3.1(+) vector were as control groups.Morphology change of K562 cells was detected by Wright stain,and cell proliferation activity was detected by MTT. Cell cycle and apoptosis of K562 cells were assessed by FCM. The expression of apoptosis-related protein,including bcl-xl,Mcl-1 and Bax were detected by Western blot.Results Wright stain showed that typical apoptotic morphology of K562 cells were observed in DCN transfected group. There were no morphological changes of apoptosis in other groups. MTT method results showed that proliferation inhibition rate of the transfected cells [24 h (16.14±1.08) ％,48 h (14.07±1.01) ％,72 h (20.29±1.19) ％]was higher than that of the other control groups (P ＜ 0.05).FCM results showed that the apoptosis index (20.15±1.31) ％of the DCN transfected group was higher than that of the other groups (P ＜ 0.05),and most of cells arrested in the G0/G1 phase (51.15±0.57) ％ (P ＜ 0.05).Western blot results showed the expression levels of Bax were increased while bcl-xl and Mcl-1 were decreased in pcDNA3.1(+)-DCN/K562 group.Conclusion rhDCN can inhibit the growth of K562 cells and induce the apoptosis.The effect of DCN on bcl-xl,Mcl-1,Bax may play a role in its mechanism. Key words: Decorin; K562 cells; Apoptosis; Cell cycle; bcl-xl; Mcl-1; Bax