In vitro response of human pathological hematopoietic cells to cladribine

The influence of cladribine (2-chloro-2'-deoxyadenosine, CdA) on in vitro response of human acute lymphoblastic leukemia MOLT-4 cells, human histiocytic lymphoma U-937 cells, and human promyelocytic leukemia HL-60 cells, was determined using the MTT spectrophotometric and Beckman Coulter methods. Cell viability, cell volume and count were compared 24h and 48h after cladribine application at four concentrations--50 nM, 100 nM, 250 nM, and 500 nM. Different patterns of temporary changes in the viability, volume and count of pathological hematopoietic cells exposed to the action of CdA were found. The effects of CdA on MOLT-4, U-937, and HL-60 cells were dependent on the agent tested and its concentration, the time intervals after agent application, and the cell line used. The various in vitro cytotoxic activities of CdA against the three human pathological hematopoietic cell lines were shown.