ZGDHu-1 induces G2/M phase arrest and apoptosis in Kasumi-1 cells.

ABSTRACT

The present study examined the effects of N,N'­di­(m­methylphenyi)­3, 6­dimethyl­1, 4­dihydro­1,2,4,5­tetrazine­1,4­dicarboamide (ZGDHu­1), a novel oxazine derivative, in Kasumi­1 cells. Following incubation with various concentrations of ZGDHu­1, fluorescence­activated cell sorting (FACS) was used in order to detect changes in mitochondrial membrane permeability in Kasumi­1 cells. Western blot analysis was performed in order to analyze the expression of nuclear factor­κB, inhibitor of κB and AML1/ETO. In addition FACS was used to analyze leukemia cell cycles and the expression levels of cyclin, cyclin­dependent kinases and cyclin­dependent kinase inhibitors in G2/M phase were determined using FACS and western blot analysis. The upregulation of reactive oxygen species production and mitochondrial membrane permeability was ascribed to apoptosis. The growth of Kasumi­1 cells was inhibited through the downregulation of nuclear factor­κB, degradation of AML1/ETO fusion protein and cell cycle arrest at the G2/M phase. This study documented that G2/M regulatory molecules, including cyclin B1, cell division control (cdc)2 and cdc25c were downregulated and checkpoint kinase 1 (CHK1), p53, p27, phospho­cdc25c, phospho­CHK1 and phospho­p53 were upregulated following treatment with ZGDHu­1. In the present study, pretreatment with CHIR­124, a selective CHK1 inhibitor, abrogated G2/M arrest via ZGDHu­1. These results demonstrated the anti­tumor activity of ZGDHu­1, which may therefore a potential target for further investigation and may be useful for the treatment of patients with t(8;21) acute myeloid leukemia.