Sorting And Preliminary Studying Of Side Population Cells In Leukemia K562 Cell Line

Objective:â‘ To isolate and preliminarily identify whether the human chronic myeloid leukemia cell line-K562 contains side population(SP) cells or not.â‘¡To further research K562 SP cells and study the relationship between SP cells and leukemia stem cells.Methods:â‘ Flow cytometry with UV excitation light was used to detect the percentage of SP cells in Logarithmic growth period K562,which were then sorted by the fluorescence activating cell sorter,and then SP and NSP subpopulations were collected.â‘¡The expression of cell differentiation markers and the expression of multidrug resistance proteins were examined by flow cytometry technique in two subpopulations.â‘¢DNA content of two subpopulations were examined by flow cytometry.â‘£BCR/ABL fusion gene mRNA expression was measured by RT-PCR in SP and NSP respectively.Results:sP cells almost accounted for 2.7±0.5%of viable cells in K562,and could be blocked when verapamil was 50ug/ml.The CD34⁺ cells expression and the CD34⁺CD38^- cells expression in the SP subpopulation were significantly higher than that in the NSP subpopulation(P<0.05).The CD34⁺CD38⁺ cells expression and the HLA-DR⁺ cells expression in SP and NSP subpopulation did not have a significant deviation(P>0.05).Although there were no differences between these two subpopulations in P-gp expression,ABCG2⁺ cells expression in the SP subpopulation was significant higher than that in the NSP subpopulation(P<0.05).The G₀/G₁ phase cells in the K562 SP subpopulation accounted for about 80%of the total cells,and the mRNA expression of the BCR/ABL fusion gene in the SP subpopulation was lower than that in the NSP subpopulation by RT-PCR.Conclusions:The K562 cell line contains side population cells,and the proportion of SP cells is much lower.According to the significant differences between the SP subpopulation and the NSP subpopulation,the expression of CD markers and MDR proteins,the majority in a quiescent period,and the positive fusion gene,it is possible that leukemia stem cells are enriched in SP cells.