[Differentiation phenotypes of k562 cells induced by exogenous wnt5a]

This study was aimed to investigate the effect of exogenous Wnt5a on directional differentiation of K562 cells. Wnt5a and GFP condition mediums were prepared by recombinant adenoviral vector AdWnt5a and AdGFP transfecting CHO cells. K562 cells were treated with Wnt5a and the GFP condition mediums for 1 - 7 days as Wnt5a treated group and control group respectively. The morphological changes of K562 cells were observed by light microscope and electron microscope; the differentiation phenotypes of K562 cells were identified by the cytochemical staining of POX, PAS, alpha-NAE and immunocytochemistry of CD13, CD14, CD68, and the effect of Wnt5a on cell cycle distribution of K562 cells was detected by flow cytometry. The results showed that the morphology and ultrastructure of K562 cells treated by Wnt5a displayed differentiation mature feature; both POX and PAS staining showed higher positive ratio in Wnt5a treated group than that in control group; the alpha-NAE staining also was positive, but positive intensity in Wnt5a treated group could be inhibited up to 70% by NaF. The expressions of monocytic differentiation antigens of CD14, CD68 in Wnt5a treated group were higher than those in control group, but the expression differences of granulocytic differentiation antigen CD13 between Wnt5a treated group and control group were not significant. The cell cycle in treated group was blocked at G2 phase as compared with control group. It is concluded that exogenous Wnt5a can induce K562 cells to differentiate towards mature and K562 cells treated with Wnt5a displays features of differentiation towards monocytic lineage.