[Homoharringtonine Induces Apoptosis of K562 Cells through Inhibition of P210(bcr/abl)]
In this study, the underlying antileukemic mechanisms of homoharringtonine (HHT) were investigated. K562 cell line was used to observe the effects of HHT on the induction of apoptosis and on the expression of the specific chimeric protein P210(bcr/abl), as evaluated by flow cytometric annexin V-PI dual labeling technique and Western blot. The results showed that HHT induced K562 cells to apoptotic death at the concentrations of 5 - 20 ng/ml, and some of the cells became necrotic when exposed to a higher concentration. The amount of P210(bcr/abl) oncoprotein was decreased by approximately 70% when the cells were exposed to HHT for 48 hours, however, that of its partner P145(c-abl) proto-oncoprotein was not affected. It is clear from the study that HHT is an inhibitor of P210(bcr/abl) oncoprotein and therefore promotes the apoptosis of CML cells. It could be promising that HHT be used extensively in the chemotherapy of patients with CML.
Wang
Hengxiang
H
Department of Hematology, Western Diaoyutai Hospital, Beijing 100036, China.
Guo
Zikuan
Z
Ji
Shuquan
S