DIFFERENTIAL-EFFECTS OF CYANOHYDROXYBUTENE AND SELENIUM ON NORMAL ANDNEOPLASTIC CANINE MAMMARY CELLS IN-VITRO

The in vitro responses of canine mammary tumor (CMT-13) cells and norm al canine mammary (NCM) cells to 1-cyano-2-hydroxy-3-butene (CHB), a n aturally occurring nitrile in cruciferous plants, and selenium (Se) we re investigated. CHB at 10 and 20 mM inhibited growth and viability of CMT-13 and NCM cells, respectively. This differential sensitivity was associated with a decreased ability of CMT-13 cells to increase intra cellular glutathione (GSH) in comparison to NCM cells. Exposure of bot h cell types to 3.2 muM Se as sodium selenite alone had no effects, bu t addition of 3.2 muM Se 24 h after exposure to non-toxic doses of CHB resulted in a substantial decrease in growth of CMT cells, while NCM cells remained unaffected. The synergy noted between CHB and Se in inh ibiting growth and viability of neoplastic mammary cells at levels not toxic to normal mammary cells is promising initial evidence that CHB could have a role in chemoprotection or chemotherapy.