N-[4-(4,6-Dimethyl-2-pyrimidinyloxy)-3-methylphenyl]-N'-[2-(dimethylamino)] benzoylurea induces cell-cycle arrest and apoptosis in human cancer cells.

N-[4-(4,6-Dimethyl-2-pyrimidinyloxy)-3-methylphenyl]-N'-[2-(dimethylamino)]benzoylurea (SUD) is a novel synthesized benzoylurea derivative. We selected several human cancer cell lines to investigate whether SUD can inhibit the growth of cancer cells. We selected the liver cell line L-02 to investigate the effect of SUD on the normal cells. Flow cytometric analysis was used to detect the effect of SUD on cell cycle, Hoechst 33258 staining was used to evaluate the apoptosis induced by SUD, real-time fluorescence quantitative PCR was used to investigate the expression of the cell cycle-relevant and apoptosis-relevant genes, a reactive oxygen species (ROS) assay was used to observe the production of ROS, and western blotting was used to determine the level of cell cycle-relevant and apoptosis-relevant proteins. According to the results of the MTT assay, the growth of human cancer cell lines was significantly inhibited by SUD treatment in a time-dependent and concentration-dependent manner; however, the growth of human normal cells was not significantly inhibited by SUD treatment. The results of flow cytometric analyses showed that SUD induced cell-cycle arrest at the G2-phase in MCF-7 cells and at the G1-phase in BGC-823 cells. The results of Hoechst 33258 staining showed that SUD induced apoptosis in MCF-7 and BGC-823 cells. The results of the ROS assay showed that the production of ROS was increased by SUD in MCF-7 and BGC-823 cells. Our research suggests that the growth-inhibitory effect of SUD on MCF-7 cells was related to G2-phase arrest, which was associated with the upregulated expression of p53 and Chk1 proteins, and downregulation of the cyclin B1 gene, cdc25a, and cyclin-dependent kinase 1 (CDK1) proteins; the growth-inhibitory effect of SUD on BGC-823 cells was related to G1-phase arrest, which was associated with upregulation of the p53 gene and Chk1 protein and downregulation of cdc25a protein and the CDK4 gene. SUD also induced apoptosis in MCF-7 and BGC-823 cell lines through the mitochondrial pathway in a p53-dependent manner.