Selective destruction of leukaemic cells by photo-activation of 5-aminolaevulinic acid-induced protoporphyrin-IX

The effect of 5-aminolaevulinic acid-based photodynamic therapy (ALA-PDT) o n the viability and proliferation of leukaemia/lymphoma cells as well as no rmal human lymphocytes has been investigated by flow cytometry-propidium io dide assay (FC-PI), 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium b romide (MTT) assay and bromodeoxyuridine (BrdU) incorporation and on clonog enic activity of normal human bone marrow progenitor cells by clonogenic me thods. ALA-PDT (1 mM 5-ALA, 4 h, 18 J cm(-2)) reduces the number and/or sup pressed proliferation of leukaemic cells of promyelocytic (HL60), B-cell-de rived (DAUDI) and T-cell-derived (JURKAT) cell Lines by 2 logs and that of the HEL erythroleukaemia cells by 77%. The effect of ALA-PDT on quiescent h uman lymphocytes is small (85% viable cells after ALA-PDT). The proliferati on of lymphocytes subjected to ALA-PDT and induced with phytohaemagglutinin (PHA) decreases by 75% as compared to the untreated control. For normal hu man bone marrow progenitors, 58% of colony-forming units-granulocytes-macro phages (CFU-GM) and 55% burst-forming units-erythrocytes (BFU-E) activities are preserved. (C) 1998 Elsevier Science S.A. All rights reserved.