LOW SAMPLE VOLUME CAUSES DIFFERENTIATION IN HUMAN RHABDOMYOSARCOMA CELL-LINE RD SUBJECTED TO ELECTROPORATION

Gene transfection has been accomplished with a variety of techniques s uch as DEAE dextran, calcium phosphate coprecipitation, protoplast fus ion, liposomes, microinjection and recombinant bacteriophages. However , transfection by electroporation, consisting of the reversible permea bilization of cell membranes after exposure to a pulsed electric field , has been shown to be the most rapid, simple and efficient method for the stable incorporation of genes in different cell lines. We studied rhabdomyosarcoma cells subjected to electroporation in two different vol. [400 mu l (group 1) and 150,mu l (group 2)] of 140 mM NaCl/15 mM Hepes buffer, pH 7.2) and evaluated the effect of electroporation volu me on growth and differentiation. Low sample volumes induced a termina l process of morphological and ultrastructural myogenic differentiatio n in rhabdomyosarcoma cells, which concluded with cell death. Our resu lts suggest that in electroporation low sample vol. of rhabdomyosarcom a cells induced morphological and phenotypic differentiation, with inc reased expression of desmin, alpha-actinin and tropomyosin.