Lineage-related susceptibility of human hemopoietic cell lines to apoptosis

Apoptosis plays a fundamental role in shaping normal hematopoiesis. We have investigated the relationship existing between susceptibility to apoptosis and lineage commitment in hemopoietic cells. The presence and degree of apoptosis were investigated in myeloid (HL-60 an d K562), T (Jurkat and MOLT-4), and B (CESS and Raji) lymphoid cell lines b y using a variety of techniques-transmission electron and light microscopy, flow cytometry and DNA gel electrophoresis. The major achievement of this study is that hematopoietic cells respond to different chemical (staurosporin, tiazofurin, camptothecin) and physical (h yperthermia or hypothermia) stimuli by apoptosis in a Lineage-related way. Moreover, with respect to the methods used to detect apoptosis, a strong co rrelation was observed between the presence of the hypodiploid peak determi ned by flow cytometry and the DNA laddering evaluated by gel electrophoresi s, but both techniques failed to demonstrate the presence of apoptosis in s ome cases. We conclude that cells of different hematopoietic lineages mostly show a Li neage-related behaviour in their apoptotic response to different stimuli, s uggesting that the lineage commitment and the stage of differentiation can confer different sensitivities to specific apoptotic stimuli. Moreover, mor phological techniques still represent the most reliable approach to detect apoptosis in hemopoietic cells. Anat Rec 254:1-6, 1999. (C) 1999 Wiley-Liss , Inc.