The Effect And Molecular Mechanisms Of Icaritin On K562 Leukemia Cells In Proliferation Inhibition And Apoptosis Induction

Background:Chronic myeloid leukemia(CML) is a malignant hematopoietic stem cell disease characterized with the Philadelphia chromosome.The characteristic chromosomet(9;22)(q34;q11) of CML result in bcr/abl fusion gene and encode protein P210,which plays an important role in the incidence of CML.Although the traditional treatment methods of CML,including hydroxyurea,interferon-α, allogeneic hematopoietic stem cell transplantation and newly tyrosine kinase inhibitors,have improved greatly,there are still some limitations. Therefore,searching for new treatment methods for CML is still the research objective.In recent years,the use of traditional Chinese medicine extracts on the treatment of leukemia has been made very good efficiency.The research on the anti-leukemia mechanism of Chinese medicine effective components and its clinical application has become an important issue.K562 cell line comes from acute leukemia which changed from human CML and with the Philadelphia chromosome.K562 cell.line is good study model of cell for the drug research in vitro.Icaritin is a simple compound extracted from some plants.In this study,we used K562 cell line as a model system to observe the effect of Icaritin on cell proliferation and apoptosis of CML cells and explore its molecular mechanisms.PartⅠProliferation-inhibiting effect of Icaritin on K562 cellsObjective:To determine proliferation-inhibiting capability of Icaritin on K562 cells.Methods:K562 cells were treated with different concentrations of Icaritin,and then cell viability was analyzed with trypan blue exclusion test,MTT(3-(4,5-dimethylthiazol-2yl)-2,5 diphenyl tetrazolium bromide) colorimetric assay test.Results:Icaritin effectively inhibited the proliferation of K562 cells in a concentration-dependent way,and the IC50 was 8μmol/L.Conclusion:Icaritin can inhibit proliferation of K562 cells effectivelyPartⅡApoptosis-inducing effect of Icaritin on K562 cells and its molecular mechanismsObjective:To ensure whether Icaritin can induce the apoptosis of K562cells and explore its molecular mechanisms.Methods:After K562 cells were incubated with different concentrations of Icaritin,(1) morphologic character of apoptosis was evaluated by Hochest33258 staining;(2) the percentage of earlier apoptosis cell was analyzed by flow cytometry;(3) the molecular character of apoptosis was analyzed by Western blot detecting Caspase-3,Caspase-9,Bax,Bcl-2,Cyt-C expression.Results:(1)Hochest33258 staining and flow cytometry detection testify Icaritin can induce the apoptosis of K562 cells in a concentration-dependent way;(2) The apoptosis of K562 cells,which was induced by Icaritin,kept company with cleavage of Caspase-3 and Caspase-9,change of Bcl-2/Bax and release of Cyt-C.Conclusion:Icaritin can induce the apoptosis of K562 cells with a concentration-dependent manner;The molecular mechanisms of apoptosis-inducting was related to cleavage and activation of Caspase-3,Caspase-9,change of Bcl-2/Bax and release of Cyt-C,suggesting the mitochondrial apoptotic pathway has something to do with the molecular mechanisms of Icaritin-induced K562 cells apoptosis.