Objective: To investigate the effects of selenium chitosan（Sc） on proliferation of human chronic myelogenous leukemia cell line K562 and explore its relationship with the expression of bcr /abl fusion gene.Method: After treatment with Sc

cell proliferation was determined with SRB and clonal assay.The abundance of P210bcr/ablprotein was examined with Western blotting.The expression of bcr /abl fusion gene was detected by RT-PCR.Result: Exposure of K562 cells to 50

100 and 200 mg·L-1 of Sc

respectively

for 48h could obviously inhibit proliferation and decrease their survival rate（P < 0.05

P < 0.01）;After treatment with 50

100

200 mg·L-1 of Sc

respectively

for 48 h or 200 mg.L-1 of Sc for 12

24

and 48 h

the abundance of P210bcr/ablprotein in K562 cells was down-regulated in a concentration and time-dependent manner（P < 0.05

P < 0.01）

but the expression of bcr /abl fusion gene was not changed.Conclusions: Sc could inhibit the proliferation of K562 cells cultured in vitro

and this effect was correlated with down-regulation of the abundance of P210bcr/abl proteins encoded by bcr /abl fusion gene.