Fig. 2

Combination of TPT and ATRA induce apoptosis in HL60 cells. a and b Effects of ATRA in combination with TPT and ATRA on cell cycle kinetics of HL60 cells. Cell cycle analysis was done after propidium iodide (PI) staining on cells exposed to TPT or ATRA either alone or in combination as indicated. *: Compared to 40 nM TPT group, p < 0.05. c Morphology of apoptotic bodies in HL60 cells treated with TPT, ATRA, or combination for 48 h. Cells were stained with DAPI and observed by fluorescence microscope (magnification 200×). d HL60 cells were exposed to TPT, ATRA, or combination for 24 h, after which, protein extracts were immunoblotted with specified antibodies for PARP and cleaved-caspase-3. e. HL60 cells were pretreated with 25 μM Z-VAD-FMK (the pan-caspase inhibitor) for 1 h and treated with TPT and/or ATRA for 24 h. The cells were analysed on flow cytometry. *: Compared to ethanol group, p < 0.05. The experiments were performed three times independently, and the error bars represent the SD around the mean