PREFERENTIAL PHOTOINACTIVATION OF LEUKEMIA-CELLS BY ALUMINUM PHTHALOCYANINE

The efficacy of chloroaluminum phthalocyanine (AIPc) for photodynamic therapy (PDT) has been evaluated in vitro on acute myeloid leukemia (A ML) cells, normal peripheral blood leukocytes (PBL) and mobilized peri pheral blood stem cells (mPBSC), The selectivity of the treatment has been evaluated by mixing PBL and TF-1, an erythroleukemic cell line. U pon photoradiation. this photosensitizer leads to a significant and pr eferential photokilling of leukemia cells in comparison to normal cell s. The use of stimulated lymphocytes in PBL/TF-1 mixtures instead of r esting cells also leads to a preferential killing towards TF-I althoug h activated PBL are more affected than resting PBL, The analysis of AI Pc intracellular emission by flow cytometry shows that the uptake of t he dye by leukemia cells is faster. This good efficacy towards AML and the observed lower phototoxicity towards normal cells (PBL, normal pr ogenitors) suggest that this phthalocyanine is a potential bone marrow purging agent. (C) 1998 Elsevier Science S.A. All rights reserved.