Preliminary Study On The Side Population Cells In Human Lymphoma Cell Line-Raji

Objective To examine whether the human lymphoma cell line—Raji contains SP cells.We further investigated the difference between SP and main population(MP) cells,including the expression of CD markers and MDR-protein,and the DNA content.Methods We used the flow-cytometry with UV to detect the percentage of SP cells in Raji,which were sorted and collected,then we tried to analyze the experssion of CD34,CD20,CD19,CD5,P-gp,and the DNA content in SP cells compared with MP cells.Results SP cells accounted for about 2%of viable cells in Raji,and could be blocked when Verapamil was 50ug/ml;SP expressed 18.2%CD20+cells compared with MP(93.6%CD20+),78.0%CD5+celIs compared with MP(22.2%CD5+),and 18.0%CD34+ cells;significant difference was observed(P＜0.05);Although the expression of P-gp were similar between the two population,the P-gp(+)cells in SP displayed more intensive fluorescence,nearly twice as those in MP;nearly all the MP cells we collected were diploid(G0/G1＞90%),but the cells in G0/G1 phase just accounted for about 50%of Raji.Conclusions Absolutely Raji contains SP cells,which is a heterogeneous subset according to the significant difference from MP on the experssion of CD markers and P-gp;we supposed that lymphoma might be organized similarly as hierarchy, and it is possible that lymphoma stem cells are enriched in SP cells.