阿霉素诱导Jurkat白血病细胞凋亡及上调Fas配体和Fas相关死亡域(英文)

Induction of Apoptosis and Upregulation of Fas Ligand and Fas-Associated Death Domain by Doxorubicin in Human Jurkat Leukemia T-Cells

目的研究阿霉素诱导白血病细胞凋亡的剂量及时间关系,探索其相关的分子机制。方法分别以0.1、0.2、0.5、1.0 mg/L的阿霉素处理人类Jurkat白血病细胞61、22、44、8 h。其中一份样本在加入0.2 mg/L阿霉素前用zVAD-fmk(苄氧羰-缬氨酰-丙氨酰-天冬氨酰-氟甲基酮)预处理。应用AnV/PI双染细胞,在流式细胞仪上分析AnV/PI双阳性的凋亡细胞。采用Western Blot技术检测FasL和FADD(Fas相关死亡域)的表达。结果6 h时所有剂量的阿霉素诱导的凋亡细胞无显著差异(P>0.05),在12 h,只有1.0 mg/L诱导细胞明显凋亡。当细胞与0.2和0.5 mg/L的阿霉素共同培养24 h或36 h,观察到调亡细胞显著增加(P<0.001)。在zVAD-fmk存在的情况下,当细胞与阿霉素一同培养时,由阿霉素诱导的细胞凋亡完全受到抑制(P<0.001)。随着阿霉素作用时间增加,FasL和FADD表达水平相应增加。结论在阿霉素诱导的白血病细胞凋亡中,阿霉素以剂量和时间依赖方式诱导细胞凋亡;上调FasL可能启动FasL信号通路的激话,而caspase是最终的执行者。

Objective To investigate the dose and time kinetics of induction of apoptosis induced by doxorubicin in Jurkat leukemia cells, and to explore its lxerlinent molecular mechanisms. Methods Human Jurkat leukemia T - cells were treated with doxorubicin at the concentration 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 pretreated with zVAD- fmk （benzyloxycarlxmyl - Val - Ala- Asp- fluoromethylketone） prior to addition of doxoruhicin 0.2 mg/L. Apoptosis was detected wilh both annexin V - FITC and propidium iodide （PI） staining and annexin V- FITC-and PI double posifive cells were analyzed by flow cytometry. WesTern blot was used to evaluate the level of Fas ligand （FasL） and FADD （Fas - associated death domain） expression. Results The differences of apoptotic cells induced by all dose of doxorubicin were not significant （ P 〉 0.05 ） at 6 hour; at 12 hour, only the highest dose, 1mg/L, significantly induced cell apoptosis; while The lowest dose, 0.1 mg/L, did not significantly caused cell apoptosis for all time poims. After exposure to the doses of 0.2 and 0.5mg/L for 24 or 36 hours,a significant increase in percentage of apoptotic cells was observed （ P 〈 0.001 ）. Apoptosis induced by doxorubicin was completely inhibited when the cells were incubated with doxorubicin in the presence of zVAD- fmk （P〈 0.001 ）. The level of FasL and FADD expression correspondingly increaed with exposure time to doxorubicin. Conclusions Doxorubicin induces apoptosis in a dose - and time - dependent manner; upregulated FasL may initiate the aclivation of the Fas signaling pathway and caspases are the ultimate executioner in the induction of leukemia cell apoptosis by doxorubicin.