[Pharmacological studies of N-4-(hydroxycarbophenyl) retinamide]

Our studies show that the growth of transplantable chondrosarcoma in rats is inhibited significantly by N-4-(hydroxycarbophenyl) retinamide (RII) at a dosage of 50 mg/kg. RII show a weak ability to induce the differentiation of HL-60 cells at a concentration of 1 umol/L. However, most of the HL-60 cells were induced to differentiate along granulocyte lineage after exposure to RII (1 mumol/L) and S86019 (10 micrograms/ml). Flow cytometry studies indicated that the majority of HL-60 cells were arrested in G1 phase by RII plus S86019. Northern blot analysis clearly demonstrated that c-myc expression was inhibited after treating HL-60 cells with RII plus S86019 for 12 hours. Moreover, thymidylate synthetase mRNA transcription was inhibited in those differentiated cells.