N-(4-hydroxyphenyl) retinamide is anticlastogenic in human lymphoblastoid cell lines

The in vitro anticlastogenic effects of a new synthetic retinoid derivative, N-(4-hydroxyphenyl)-retinamide (4-HPR), were studied in two human lymphoblastid cell lines (3640P and 4087P). Cell cultures were preincubated 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 (3640P) and 0.73 (4087P). The presence of 10(-6) M 4-HPR significantly decreased 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). Incubation with the lowest concentration (10(-9) M) of 4-HPR did not decrease b/c values. These preliminary data demonstrate that 4-HPR has anticlastogenic effects in vitro and are similar to our results from previous studies on the in vitro antigenotoxic effects of 13-cis-retinoic acid (Trizna Z et al, Eur J Cancer, 1993, 29A: 137-140).