ANTICLASTOGENIC EFFECTS OF 13-CIS-RETINOIC ACID INVITRO

The anticlastogenic effects of 13-cis-retinoic acid were studied in four human lymphoblastoid cell lines and in primary lymphocyte cultures derived from the peripheral blood of 11 study subjects. Cells were pre-incubated with 13-cis-retinoic acid in the concentration range of 10(-8)-10(-5) mol/l for 24 h and the numbers of chromatid breaks per cell induced by bleomycin were determined. The presence of 13-cis-retinoic acid decreased the number of breaks per cell by 13.0 to 59.5% in lymphoblastoid cell lines and by 0 to 57.4% in primary lymphocyte cultures (in the concentration ranges of 10(-8)-10(-6) mol/l and of 10(-8)-10(-5) mol/l, respectively). Regression analysis showed that there was a statistically significant correlation between the presence of 13-cis-retinoic acid and protection against bleomycin-induced clastogenicity. These data give additional information to the knowledge of possible chemopreventive mechanisms of action of 13-cis-retinoic acid.