INHIBITORY EFFECTS OF SELENIUM, VITAMIN-A AND BUTYLATED HYDROXYTOLUENE ON IN-VITRO GROWTH OF HUMAN TONGUE CANCER-CELLS

The effects of vitamin A, selenium and butylated hydroxytoluene (BHT) on the growth of a human tongue cancer cell line were examined in mono layer cell cultures.:A colony-forming assay showed a 50% reduction in the survival rate of the cell line at a concentration of 2.6 mu g/ml s elenium, 60 mu g/ml vitamin A and/or 38 mu g/ml BHT. Relatively low co ncentrations of selenium markedly inhibited glucose consumption. Flow cytometric analysis with both fluorescein-isothiocyanate-labelled brom odeoxyuridine monoclonal antibody and propidium iodide demonstrated an increase in S-phase fractions 1 day after the addition of selenium, i ncreased G0/G1 phase fractions in the presence of vitamin A and increa sed G2-M phase fractions when BHT was added. These results suggest tha t these compounds inhibit DNA synthesis of in vitro human tongue cance r cells by different mechanisms.