MECHANISM OF PROLIFERATIVE INHIBITION OF γ-IFN AND ORIDONIN ON U937 CELLS

Objective:To investigate the inhibitory effect of γ interferon (γ INF) and Oridonin on U937 cells (acute leukemia strain) and its mechanism.Methods:The variation of morphology of U937 cells were observed in culture medium with γ IFN (2×10 6U/L) and various concentrations of Oridonin at different time in vitro.The inhibitory ratio was measured by MTT assay,apoptosis was obsevered by flow cytometry (FCM) and typan staining as well as hoechst 33258 fluorescence staining , and the activity of telomerase was detected using TRAP PCR ELISA before and after apoptosis occurred.Results:γ IFN and Oridonin could decrease the activity of telomerase, as well as cause apoptosis and inhibit the growth of U937 cells significantly .The suppression was both in time and dose dependent manner.Conclusion:γ IFN and Oridonin using concurrently can inhibit the proliferation of leukemic U937 cells apparently in vitro, inducing apoptosis and decreasing the activity of telomerase may be one of the most important mechanisms.