Fas调节白血病细胞HL-60内Stat3的表达和磷酸化

Oligomerization of Fas death domain decreases Stat3 expression and phosphorylation in leukemia line HL-60

目的 :观察 Fas对 HL - 6 0细胞的异常增殖是否有调节作用。方法 :用基因重组技术将 Fas的细胞外区跨膜区与 IL -6信号传导子 gp130细胞内区构成嵌合型受体 (Fas/130 ) ,同时 ,将 Fas死亡区域 (Fas DD)替换 Fas/130中 130细胞内区无结构域部分 (Fas/130 f) ,分别在 HL - 6 0中表达后 ,用抗 Fas抗体激活这些嵌合型受体 ,随后用免疫组化和蛋白质印迹法分析受体细胞内区形成同源性三聚体 (130 cyt- 130 cyt- 130 cyt及 Fas DD- Fas DD- Fas DD)后细胞内 Stat3的表达及磷酸化。结果 :转染p ED Fas/130后用抗 Fas抗体作用 6～ 8h,HL - 6 0细胞 Stat3表达下降 (P<0 .0 5 ) ,而 Fas/130 f组的 Stat3的表达下降更明显(P<0 .0 1) ;两实验组中 Fas/130 f组在特异性抗体诱导 10 m in时 ,Stat3 Tyr70 5磷酸化较 Fas/130组明显降低 (P<0 .0 1)。结论 :Fas死亡域抑制白血病 HL- 6 0细胞内 Stat3的表达 ,并同时抑制 Stat3Tyr70 5磷酸化。

Objective: To investigate the cause of proliferation disorder of leukemia cell and the cell proliferation inhibition of the Fas death domain (FasDD). Methods: We analyzed Stat3 expression level in human leukemia line HL 60 transfected various chimerical receptors. The chimerical receptor changed Fas cytoplasmic domain with IL 6 related transducer, gp130 (Fas/130) or with gp130 cytoplasmic region containing Fas death domain (Fas/130f), then let it separately express on the membrane of HL 60. The oligomeric of the cytoplasmic regions (130cyt 130cyt 130cyt or FasDD FasDD FasDD) was induced by anti Fas antibodies for initiating the intracellular signal transduction. Stat3 expression level was observed by means of immunoblotting and immunobiochemistry in HL 60. Results: Lower level of Stat3 and the faster cell proliferation were determined in group Fas/130 and Fas/130f compared with the control, and the lowest was in group Fas/130f. The decrease of Stat3 phosphorylation was at the same level in 2 positive groups at 10 min, those of Fas/130f was the lowest in all groups. Conclusion: FasDD may inhibit Stat3 expression and Stat3 Tyr705 phosphorylation.