EFFECTS OF ORGANIC AND INORGANIC SELENIUM-COMPOUNDS ON RAT MAMMARY-TUMOR CELLS

To explore cellular effects of potent organoselenium chemopreventive a gents we have used a rat mammary tumor cell line. We demonstrate that 1,4-phenylenebis(methylene) selenocyanate (p-XSC) at a dose of 5 mu M is a more potent inhibitor of DNA, RNA and protein synthesis as well a s of mitochondrial transmembrane potential than its chemopreventive co unterparts benzyl selenocyanate (BSC) and sodium selenite. These diffe rences were also reflected in reduced growth rate by 24 and 48 hr. Cel l-cycle and cell-morphology analysis revealed that higher doses of p-X SC (10 mu M) caused DNA fragmentation which was accompanied with parti al loss of nuclear stainability, whereas BSC caused a noticeable chang e in cell-cycle distribution and extensive micronucleation. Overall, o ur results point to cellular targets of selenium compounds which may m ediate their chemopreventive activities in mammary tissues. (C) 1995 W iley-Liss, Inc.