The induction of apoptosis by theasinesin in HL-60 cells

AIM To investigate the mechanism of the anticancer effect of theasinesin. METHODS MTT assay, electronic microscopy technique, DNA gel electrophoresis, flow cytometric analysis with Annexin V Fluos staining,RT PCR and immunocytochemistry were performed for apoptosis and its mechanism. RESULTS After HL 60 cells were treated with theasinesin, HL 60 cells were characterized by condensation of the nuclear chromatin, margination against the nuclear envelope, and apoptotic body formation with scanning and transmission electronic microscopy. A typical DNA ladder was detected by agarose gel electrophoresis of DNA extracted from HL 60 cells. Flow cytometric analysis of HL 60 cells by Annexin V Fluos and propidium iodide double staining demonstrated that theasinesin induced apoptosis had dose effect and time effect relationships, but treatment with high dose or long time would induce cell necrosis principally. RT PCR and immunocytochemistry indicated that bcl 2 gene was reduced strongly in HL 60 cells. CONCLUSION Theasinesin induces apoptosis in HL 60 cells. The mechanisms for antitumor activity of theasinesin may involve in induction of apoptosis in cancer cells.