Objective      To determine the effect and mechanism of ROR2 on inhibiting proliferation and inducing apoptosis in chronic myeloid leukemia cell line K562.       Methods      ROR2 recombinant adenovirus (AdROR2) was used to infect K562 cells (experimental cells)

and the cells infected by RFP recombinant adenovirus (AdRFP) served as control cells. CCK-8 assay was employed to detect the cell proliferation

and flow cytometry was adopted for cell cycle and apoptosis. The expression levels of pro-apoptotic protein caspase 3 and anti-apoptotic protein were detected in both groups of cells by Western blotting.       Results       In 48 h after

the infection of ROR2 recombinant adenovirus AdROR2

the proliferation of K562 cells was significantly inhibited (P0.05)

cell cycle was arrested at the G

2

/M phase (P0.05)

the amount of apoptotic cells was increased

and cell apoptosis was obviously enhanced (P0.05) when compared with the control cells. At the same time

the expression level of caspase 3 was increased (P0.05)

and that of survivin was decreased (P0.05).       Conclusion      Over-expression of ROR2 inhibits the proliferation and induces the apoptosis of K562 cells

which may be due to its up-regulating of pro-apoptotic protein caspase 3 while down-regulation of anti-apoptotic protein survivin.