Abstract
The present study examined the effects of N,N'‑di‑(m‑methylphenyi)‑3, 6‑dimethyl‑1, 4‑dihydro‑1,2,4,5‑tetrazine‑1,4‑dicarboamide (ZGDHu‑1), a novel oxazine derivative, in Kasumi‑1 cells. Following incubation with various concentrations of ZGDHu‑1, fluorescence‑activated cell sorting (FACS) was used in order to detect changes in mitochondrial membrane permeability in Kasumi‑1 cells. Western blot analysis was performed in order to analyze the expression of nuclear factor‑κB, inhibitor of κB and AML1/ETO. In addition FACS was used to analyze leukemia cell cycles and the expression levels of cyclin, cyclin‑dependent kinases and cyclin‑dependent 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 Kasumi‑1 cells was inhibited through the downregulation of nuclear factor‑κB, 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, phospho‑cdc25c, phospho‑CHK1 and phospho‑p53 were upregulated following treatment with ZGDHu‑1. In the present study, pretreatment with CHIR‑124, a selective CHK1 inhibitor, abrogated G2/M arrest via ZGDHu‑1. These results demonstrated the anti‑tumor activity of ZGDHu‑1, 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.