title: Exposure of human leukemic cells to direct electric current: generation of toxic compounds inducing cell death by different mechanisms.
abstract: Treatment with direct electric current (DC) influences the growth of several cancer cells. In this work, we evaluated the effects of DC treatment on the human leukemic cell line HL60. Human cells were separately treated in the presence of the cathode or the anode or without contact with the electrodes. In all systems, DC-treated cells presented an impaired ability to proliferate. Growth inhibition was dependent on the generation of soluble products of electrolysis. Cathodic treatment of HL60 cells predominantly induced lysis, whereas treatment without contact with electrodes did not induce alterations in cell viability. In contrast, cell stimulation by the anode resulted in irreversible membrane damage, as demonstrated by trypan blue and 7-aminoactinomycin staining. Analysis of these cells by transmission electron microscopy indicated that necrosis is a major mechanism inducing cell death. In addition, apoptotic-like cells were observed under light microscopy after anodic treatment. Accordingly, DNA from anodic-treated cells presented a typical pattern of apoptosis. Apoptotic cell death was only generated after the treatment of HL60 cells in conditions in which the generation of chloride-derived compounds was favored. These results indicate that the nature of the products from cathodic or anodic reactions differently influences the mechanisms of cell death induced by DC-derived toxic compounds.
authors.affiliation: Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, CCS, Bloco K, Segundo Andar, Sala 50, Ilha do Fundão, 21941-590, Rio de Janeiro, Brazil.
authors.forename: Venicio F
authors.initials: VF
authors.lastname: Veiga
authors.forename: Leonardo
authors.initials: L
authors.lastname: Nimrichter
authors.forename: Cesar A
authors.initials: CA
authors.lastname: Teixeira
authors.forename: Marcelo M
authors.initials: MM
authors.lastname: Morales
authors.forename: Celuta S
authors.initials: CS
authors.lastname: Alviano
authors.forename: Marcio L
authors.initials: ML
authors.lastname: Rodrigues
authors.forename: Carla
authors.initials: C
authors.lastname: Holandino
mesh_terms: D016923:Cell Death / Q000528:radiation effects*; D002462:Cell Membrane / Q000378:metabolism / Q000528:radiation effects; D004558:Electric Stimulation; D004560:Electricity; D018922:HL-60 Cells; D006801:Humans; D007938:Leukemia / Q000473:pathology; D009336:Necrosis; D013997:Time Factors; D014407:Tumor Cells, Cultured / Q000473:pathology / Q000528:radiation effects*