Abstract:

BACKGROUND: It is possible that leukemia relapse is related with side population (SP) cells, which can escape cell cyles phase specific chemotherapeutic drugs .
OBJECTIVE: To isolate and preliminarily identify whether the human chronic myeloid leukemia cell line-K562 contains SP cells or not, and to further research K562 SP cells and study the expression of multidrug resistance proteins and DNA content in two subpopulations.
METHODS: 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 non-SP subpopulations were collected. The expression of multidrug resistance proteins were examined by flow cytometry technique in two subpopulations. DNA content of two subpopulations was examined by flow cytometry.
RESULTS AND CONCLUSION: The K562 cell line contained SP cells, and the proportion of SP cells was much lower. 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 non-SP subpopulation (P < 0.05). The G0/G1 phase cells in the K562 SP subpopulation accounted for about 80% of the total cells. According to the significant differences in the expression of MDR proteins between the SP subpopulation and the non-SP subpopulation, and the majority in a quiescent period, it is possible that leukemia stem cells are enriched in SP cells.