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[The Antileukemia Activity of ZSTK474 on U937 Cells].

OBJECTIVE
To investigate the antileukemia activity of phosphatidylinositol-3 kinase (PI3K) inhibitor ZSTK474 on human leukemia cell line U937.


METHODS
MTT, soft agar assay, flow cytometric analysis and western blot were used to detect the effect of ZSTK474 on U937 cell proliferation, tumorigenicity, cell cycle, cell apoptosis and phosphorylation levels of the key factor of PI3K/AKT pathway. Chou-Talalay method was used to evaluate the combination of ZSTK474 with Cytarabine or Homoharringtonine.


RESULTS
PI3K inhibitor ZSTK474 could inhibit the proliferation and tumorigenicity of U937 cell, induce G1 cell cycle arrest and promote cell apoptosis, and enhance intracellular ROS production and decrease MMP, downregulate Cyclin D1, p-Rb, BCL-2 and upregulate p27, caspase-9, caspase-3, PARP and BAX. Furthermore, the phosphorylation of PDK1, GSK-3β, AKT and mTOR could be downregulated by ZSTK474. The combination of ZSTK474 with Homoharringtonine was synergistic.


CONCLUSION
ZSTK474 can inhibit the pathway of PI3K/AKT, ZSTK474 alone or in combination with Homoharringtonine shows potential antileukemia activity on U937 cells.