[Effects of N, N-di-(m-methylphenyl)-3, 6-dimethyl-1, 4-dihydro-1,2,4, 5-tetrazine-1,4-dicarboxamide (ZGDhu-1) on SHI-1 leukemia cells in vitro].

Objective To study the effect of ZGDHu-1 on proliferation,differentiation and apoptosis in SHI-1 human leukemia cell line and explore its possible mechanism.Methods SHI-1 cells were cultured with different concentration of ZGDHu-1 and for different time.The cell proliferation was analysed by cell counting,alive cell count,MTT assay and Brdu-ELIISA.Cell apoptosis was analysed by morphology,DNA content,Annexin-V/PI and Hoechst 33258 labeling method.Cell differentiation were assayed by morpholo- gy,expression of CD11b,CD14 and CD64 and NBT reduction.The expressions of phosphorylated p38MAPK or STAT3 were analysed by flow cytometry,Results ZGDHu-1 inhibited SHI-1 cell prolifdration in a time and dose dependent maunner,the IC_(50)-48 h and IC_(50)-72 h were 250ng/ml and 85 ng/ml,respectively.The majority of SHI-1 cells were arrested in G_2/M phase.48h after treated with 200ng/ml ZGDHu-1,and those ni G_2/M phase accounted for(48.4±2.1)%,The SHI-1 cells apoposis was increased with a time-and does- dependent manner.The morphology of SHI-1 cells cultured with 2-50 ng/ml ZGDHu-1 for three days be- come more mature with higher NBT positivity and up-regulated expressions of CD11b,CD14 and CD64.The expression of phosphor-p38MAPK was increased and phosphor-STAT3 down-regulated by the treatment of ZGDHu-1.Conclusion ZGDHu-1 can inhibit SHI-1 cell proliferation and induce the cell differentiation and apoptosis.The mechanism may associate with its up-regulation of phosphor-p38MAPK and down-regulation phosphor-STAT3.