APOPTOTIC AND NECROTIC CELL-DEATH ARE BOTH INDUCED BY ELECTROPORATIONIN HL60 HUMAN PROMYELOID LEUKEMIA-CELLS

Cell death was induced by electroporation in HL60 cells, a human promy eloid leukaemia strain, in order to determine by both morphological an d biochemical criteria whether necrotic or apoptotic processes occurre d. Cells sampled at several times after electroporation were analyzed for the assessment of the following end-points: (i) chromosomal DNA fr agmentation; (ii) cell viability; (iii) mono-and oligonucleosomes in t he cytoplasmic fraction; (iv) apoptotic index; and (v) morphology of t reated cells. The results indicate that about 50% of the cells killed by electroporation die through necrosis, while the remaining 50% of th e cells undergo apoptosis. Chromosome damage was also studied by cytog enetic analysis at metaphase. The possibility of killing tumour cells by electroporation, as a variant of electrotherapy, constitutes, in ou r opinion, a promising procedure in cancer therapy, avoiding the undes irable side effects normally derived from treatment with cytotoxic dru gs.