The Study On The Cell Differentiation During Cell Cycle Progression

BACKGROUND AND OBJECTIVE:Cell differentiation is a core problem in cell biology. Many researchers believed that cell differentiation is related with cell cycle,but mechanisms that how cell cycle regulates cell differentiation remains unknown.In this part, we use ATRA (all-trans retinoid acid) to induce the differentiation of HL-60 cells,and to explore the relationship between differentiation and cell cycle progression in this model.METHODS:The cellular surface antigen CD11b expression of HL-60 cells were detected by flow cytometry after the cells been induced by 1μmol/L ATRA for different period. Morphological changes of differentiated cells were studied by Post-sorting Confocal(PSC).Then we used multi-parameter flow cytometry to detecte the CD11b expression and DNA content simultaneously,so we could analyze the cell cycle distributionof the CD11b-positive cells within different cycle phases.RESULTS:72 hours after the induction by ATRA,the CD11b-positive HL-60 cells was evidently increased from 1.65% to 16.68%.DNA histogram analysis revealed that cells were arrested at G0/G1 phase upon ATRA treatment.Post–sorting Confocal(PSC) showed that the nuclear morphology of the CD11b positive cells was changed to maturation. CD11b/DNA multi-parameter flow cytometry confirmed that most of the differentiated cells had the DNA content of G0/G1 phase.CONCLUSION:ATRA can induce HL-60 cell go to differentiate and the differentiation mostly occurs in G0/G1 phase. OBJECTIVE:The aim of this part is to construct a differentiated model of HL-60 cells by aphidicolin.So we can explore the relationship between cell cycle and cell differentiation.METHODS:The cellular surface antigen CD11b expression of HL-60 cells were detected by flow cytometry after the cells been induced by 1μg/ml aphidicolin for different period. Morphological changes of differentiated cells were studied by Post-sorting Confocal(PSC).Then we used multi-parameter flow cytometry to detecte the CD11b expression and DNA content simultaneously.RESULTS:12 hours after the induction by aphidicolin,the CD11b-positive HL-60 cells was increased from 0.33% to 9.68%.DNA histogram analysis revealed that aphidicolin blocked the cell progression of S phase.Post–sorting Confocal(PSC) showed that the nuclear morphology of the CD11b positive cells was changed to maturation. CD11b/DNA multi-parameter flow cytometry confirmed that most of the differentiated cells had the DNA content of S phase.CONCLUSION:Aphidicolin can induce HL-60 cell go to differentiate and the differentiation mostly occurs in S phase. OBJECTIVE:HMBA is an effective hybrid polar compound that can induce acute myeloid leukemia cells go to terminal differentiation.In this part,the effect of HMBA on the cell cycle and the differentiation of HL-60 cells was investigated.METHODS:The cellular surface antigen CD11b expression of HL-60 cells were detected by flow cytometry after the cells been induced by 10μmol/L HMBA for different period.Morphological changes of differentiated cells were studied by Post-sorting Confocal(PSC).Then we used multi-parameter flow cytometry to detecte the CD11b expression and DNA content simultaneously.RESULTS:24 hours after the induction by HMBA,the CD11b-positive HL-60 cells was evidently increased from 28.12% to 0.60%.DNA histogram analysis revealed that HMBA greatly retarded the progression of G2/M phase.Post–sorting Confocal(PSC) showed that the nuclear morphology of the CD11b positive cells was changed to maturation.CD11b/DNA multi-parameter flow cytometry confirmed that most of the differentiated cells had the DNA content of G2/M phase.CONCLUSION:HMBA can induce HL-60 cell go to differentiate and the differentiation mostly occurs in G2/M phase.