Induction of apoptosis by norathyriol in HL-60 leukemia cells
| Autor: | Xu, Zhen Yan, 許甄晏 |
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| Rok vydání: | 1995 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 83 These is accumulating evidence that efficiency of anticancer agents is related to the intrinsic propensity of the target tumor cells to respond to these agents by apoptosis.Based on this conc-ept,screening more effective compound inducing apoptosis seems to be relevant strategy to suppress the tumors. In this study,we show that norathyriol(NT),a xanthone isolated from Chinese herbs Tripterosperum lanceolatum,can induce a typical apoptosis in human leukemia HL-60 cells at a concentration of 50 uM.This NT-induced apoptosis was determined as nuclear condensa-tion,internucleosomal DNA ladder and apoptotic bodies.To under-stand better the mechanism underlying NT induce the process of apoptosis in this tumor cell,we examined several signaling transduction modulators whether affects this process.The results were shown that EGTA(a Ca chelator),TPA(a PKC activator),aphidi-colin(an inhibitor of DNA polymerase a)and 3-aminobenzamide(an inhibitor of poly(ADP-ribose)synthesis)all failed to prevent NT-induced apoptosis,but zinc (an endonuclease inhibitor) can protect cells from NT-induced cell death.Flowcytomrtry analysis shows 24hr of exposure with 100uM NT led HL-60 cells to arrest at G1 phase,indicating that NT may influence the components of cell cycle. In Western blotting, we also observed the bcl-2 oncoprotein,which is recognized as a suppressor of apoptosis, was slight decreased by treatment with 100uM NT.The result implies that the regulation of bcl-2 might not play an important role in NT-induced apoptosis.Arsenite,which can induce heat shock proteins in HL-60 cells,can partial protect NT-induced cell death.We suggest Hsp70 might be involved in NT-induced apoptosis. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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