Cellular damage and altered carbohydrate expression in p815 tumor cells induced by direct electric current: An in vitro analysis

Treatment with direct electric current (DC) can inhibit tumor growth in sev eral systems. To evaluate the cellular reactions generated by this treatmen t, we stimulated mouse mastocytoma P815 cells with DC and examined their vi ability and ultrastructural characteristics, as well as the effect of DC on surface carbohydrate expression. DC treatment affected cell viability and caused marked alterations in vital structures of P815 cells. Alterations va ried depending on the duration of stimulation and polarity of electrode. An odic and cathodic treatments caused decrease in cell viability, although th e latter was more effective in generating cell lysis. DC stimulation also i nduced changes such as membrane damage, alterations in cell shape and chrom atin organization, mitochondrial swelling and condensation, cytoplasmic swe lling, and matrix rarefaction. Stimulation of P815 cells without contact wi th electrodes produced no alterations, suggesting that this contact might b e essential for the occurrence of the cellular modifications. DC treatment also altered the membrane distribution of anionic sites of P815 cells, as w ell as the surface carbohydrate exposition, involving a diminished binding of Concanavalin A to the cell surface after cathodic stimulation, and an in creased binding of sialic acid- and fucose-specific lectins after anodic tr eatment. In this work we describe important cellular targets for the action of DC, which may contribute to the understanding of the mechanisms by whic h DC supresses several kinds of tumors. Bioelectromagnetics 21:597-607, 200 0. (C) 2000 Wiley-Liss, Inc.