N-(4-HYDROXYPHENYL) RETINAMIDE IS ANTICLASTOGENIC IN HUMAN LYMPHOBLASTOID CELL-LINES

The in vitro anticlastogenic effects of a new synthetic retinoid deriv ative, N-(4-hydroxyphenyl)-retinamide (4-HPR), were studied in two hum an lymphoblastid cell lines (3640P and 4087P). Cell cultures were prei ncubated with 4-HPR in a range of concentrations from 10(-9) to 10(-6) M for 24 h. The number of chromatid breaks per cell (b/c) induced by a 2-hour treatment with 0.004 U/ml bleomycin was determined. The mean b/c values in cell cultures treated with bleomycin alone were 0.50 (36 40P) and 0.73 (4087P). The presence of 10(-6) M 4-HPR significantly de creased this value in both cell lines to 0.27 in 3640P (p<0.01) and 0. 41 in 4087P (p<0.05). Lower concentrations (10(-7) and 10(-8) M) of 4- HPR significantly decreased b/c only in cell line 3649 (p<0.05). Incub ation with the lowest concentration (10(-9) M) of 4-HPR did not decrea se b/c values. These preliminary data demonstrate that 4-HPR has antic lastogenic effects in vitro and are similar to our results from previo us studies on the in vitro antigenotoxic effects of 13-cis-retinoic ac id (Trizna Z et al, Eur J Cancer, 1993, 29A: 137-140).