OBJECTIVETo 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-ELISA. Cell apoptosis was analysed by morphology, DNA content, Annexin-V/PI and Hoechst 33258 labeling method. Cell differentiation were assayed by morphology,expression of CD11b,CD14 and CD64 and NBT reduction. The expressions of phosphorylated p38MAPK or STAT3 were analysed by flow cytometry.

RESULTSZGDHu-1 inhibited SHI-1 cell proliferation in a time and dose dependent manner, the IC50- 48 h and IC50- 72 h were 250 ng/ml and 85 ng/ml, respectively. The majority of SHI-1 cells were arrested in G2/M phase. 48h after treated with 200 ng/ml ZGDHu-1, and those in G2/M phase accounted for (48.4 +/- 2.1)%. The SHI-1 cells apoptosis 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 become 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.

CONCLUSIONZGDHu-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.