CULTURE CONDITIONS MODULATE THE EFFECTS OF ACLACINOMYCIN-A ON GROWTH,DIFFERENTIATION AND APOPTOSIS OF HL-60 CELLS

The continuous incubation for several days of HL60 cells, in exponenti al growth, with aclacinomycin A (ACM) induces growth inhibition, necro sis, differentiation and apoptosis. Differentiation and apoptosis were assessed by optical microscopy (OM) and flow cytometry (FCM). ACM dis played dose-dependent effects, except for the differentiation inductio n, which was biphasic. Differentiation and apoptosis could also be ind uced after a 1h ACM exposure only. The poor reproducibility of apoptos is induction led us to study the culture conditions described in the l iterature (without renewing the medium) where control cells are not gr owing exponentially during the 5 day incubation period. During kinetic studies with different ACM concentrations, the differentiation was de tected earlier by FCM than by OM, while it was nor the case for apopto sis. This induction appeared more reproducible when non optimal condit ions of culture were used.