Background & objective: Harringtonine (HT),an anti-tumor drug,has been widely used to treat acute or chronic myeloid leukemia,and obtained satisfactory effects. Studies showed that the anti-tumor activity of HT is related with the apoptosis-inducing effect,but the molecular mechanisms remain unclear. This study was to analyze the protein maps contributed to the apoptosis in K562 cells induced by HT,and to screen the apoptosis-associated proteins.
Methods: Flow cytometry was used to distinguish K562 cells of early apoptosis stage from those of late apoptosis stage through Annexin V and PI staining. Two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) was used to separate and compare the HT-induced apoptotic K562 cells and control K562 cells.
Results: When K562 cells were treated with 10 microg/ml HT for 5,a nd 24 hours,percentages of early apoptotic cells (Annexin V+/PI-) were 28.3%, and 18.1%(P< 0.01), while percentages of late apoptotic cells (Annexin V+/PI+) were 9.1%,and 20.2% (P< 0.01), respectively. Statistical analysis showed (1300+/-50) protein spots were resolved with a match rate of (88.3+/-2.0)% in control K562 cells. Ten protein spots in late apoptotic cells displayed changes in expression after induction of HT for 24 hours (P< 0.01), of which 8 showed higher expression, 1 decreased,and 1 only expressed in control k562 cells.
Conclusion: These proteins may be apoptosis-associated proteins of K562 cells induced by HT.