Bcr-Abl kinase promotes cell cycle entry of primary myeloid CML cells in the absence of growth factors

1998

Cell cycle control of both immature and differentiated primary myeloid normal and chronic-phase chronic myeloid leukaemia (CML) cells to growth factor deprivation was studied. CD34+ cells were cultured in liquid culture. After removal of growth factors for 48 h normal cells were very efficiently arrested with the fraction of cells in S phase reduced by 70.8 +/- 6.5% in CD34+ and 50.5 +/- 4.2% in CD34- cells. In contrast, a significantly higher proportion of leukaemic cells remained in S phase. The fraction of S-phase cells was reduced by only 29.3 +/- 5.7% in CD34+ CML cells and 21.2 +/- 3.8% in CD34- cells. This abnormal negative cell cycle control in leukaemic cells was specific for growt…