Inhibitory effects of cancer cell proliferation by novel histone deacetylase inhibitors involve p21/WAF1 induction and G2/M arrest

Two compounds were synthesized which have a structural component other than those of our new series histone deacetylase (HDAC) inhibitors to determine the structure-activity relationship. It was also examined whether the inhibitory effects on cancer cell proliferation by HDAC inhibitors involve p21/WAF1 induction and G(1) or G(2)/M arrest in p53-mutated MG63 human osteosarcoma cells as do other HDAC inhibitors. It was demonstrated that inhibitors with the 2-naphthylcarbonyl group and hydroxamic acid at both termimal sides as well as the phenylene component at the center of molecule markedly induce the p21/WAF1 protein by stimulating p21/WAF1 gene promoter activity. Furthermore, cell cycle analysis revealed that these compounds arrest MG63 cells in the G(2)/M phase.