ABSTRACT
Objective To detect and separate the side population cells(SP) from multiple myeloma (MM) cell lines PRIM8226,and to study their biological characteristics.Methods Fluorescence activated cell sorter (FACS) and Hoechst33342/PI dye were used to sort SP cells of PRIM8226.The multiplication capacity was tested by the growth curve and MTT test,SP cells proportion and the cell cycle were analyzed by flow cytometry,the colony-formtion ability was compared in terms of colony forming experiment,the expression of c-myc,KIF4,SOX2,OCT4 was tested by RT-PCR.The oncogenicity of the cells was analyzed by nude mouse transplantation tumor experiment in vivo.Results The ratio of SP cells in PRIM8226 was (1.78±0.89) ％.More SP cells in the G0 / G1 period,(44.34±3.09) ％ vs (28.49±1.97) ％,P ＜ 0.05,and fewer cells in S phase than MP cells,(38.83±3.69) ％ vs (51.49±4.62) ％,P ＜ 0.05.There were no difference in the expression of CD38 and CD138 between SP cells and MP cells,respectively,(78.5±8.5) ％ vs (82.0±4.0) ％ and (72.3±15.7) ％ vs (84.3±11.9) ％,P ＞ 0.05.Colony formation assay showed that the colony forming efficiency of the SP cells was higher than the MP cells,single cell clone diameter,the number of clone forming,the clone formtion rate were significantly higher than MP cells,0.280±0.016 vs 0.118±0.019,1 722±127 vs 358±14,(86.1±3.46) ％ vs (17.9±1.88) ％,P ＜ 0.05.The mRNA expression levels of c-myc,KIF4,SOX2,OCT4 in SP cells were higher than those in MP cells,c-myc (29.90±3.73) ％ vs (16.84±2.35) ％,KIF4 (29.97±2.89) ％ vs (19.06±1.23) ％,SOX2 (40.00±4.58) ％ vs (16.62±2.09) ％,OCT4 (32.96±0.92) ％ vs (23.27±0.92) ％,all P ＜ 0.05.Nude mouse transplantation tumor experiment in vivo showed the oncogenicity of the SP cells was more stronger than MP cells (5×103 vs 5×l05).Conclusion There are notably difference in the cell cycle,colony formation assay,the mRNA expression levels and oncogenicity,but no difference in the expression of CD38 and CD138,the proliferation ability between SP cells and MP cells.