Induction of Apoptosis and Upregulation of Fas Ligand and Fas - Associated Death Domain by Doxorubicin in Human Jurkat Leukemia T- Cells / 实用儿科临床杂志

Objective To investigate the dose and time kinetics of induction of apoptosis induced by doxorubicin in J urkat leukemiacells, and to explore its pertinent molecular mechanisms. Methods Human Jurkat leukemia T - cells were treated with doxorubicin at theconcentration of 0.1 mg/L, 0.2 mg/L, 0.5 mg/L and 1.0 mg/L for 6,12,24 and 36 hours, respectively, of which one sample was pre-treated with zVAD- fmk (benzyloxycarbonyl - Val -Ala - Asp - fluoromethylketone) prior to addition of doxorubicin 0.2 mg/L. Apop-tosis was detected with both annexin V - FITC and propidium iodide ( PI ) staining and annexin V FITC and PI double positive cellswere analyzed by flow cytometry. Western blot was used to evaluate the level of Fas ligand (FasL) and FADD (Fas - associated death do-main) expression. Results The differences of apoptotic cells induced by all dose of doxorubicin were not significant (P＞0.05 ) at 6hour;at 12 hour, only the highest dose, 1 mg/L, significantly induced cell apoptosis;while the lowest dose,0.1 mg/L, did not significantlycaused cell apoptosis for all time points. After exposure to the doses of 0.2 and 0.5 mg/L for 24 or 36 hours,a significant increase in per-centage of apoptotic cells was observed (P ＜ 0.001 ). Apoptosis induced by doxorubicin was completely inhibited when the cells were incu-bated with doxorubicin in the presence of zVAD - fmk (P ＜ 0. 001 ). The level of FasL and FADD expression correspondingly increasedwith exposure time to doxorubicin. Conclusions Doxorubicin induces apoptosis in a dose - and time - dependent manner; upregulatedFasL may initiate the activation of the Fas signaling pathway and caspases are the ultimate executioner in the induction of leukemia cellapoptosis by doxorubicin.

Induction of Apoptosis and Upregulation of Fas Ligand and Fas-Associated Death Domain by Doxorubicin in Human Jurkat Leukemia T-Cells / 实用儿科临床杂志

0.05) at 6 hour;at 12 hour,only the highest dose,1 mg/L,significantly induced cell apoptosis;while the lowest dose,0.1 mg/L,did not significantly caused cell apoptosis for all time points.After exposure to the doses of 0.2 and 0.5 mg/L for 24 or 36 hours,a significant increase in percentage of apoptotic cells was observed(P