PKA途径活化抑制人骨髓瘤细胞U266对IL-6的反应性

Activation of PKA pathway inhibits reactivity of human myeloma cell line-U266 to IL-6

目的 研究PKA途径活化对IL 6在人骨髓瘤细胞系U2 6 6中的信号转导功能及生物学效应的影响。方法 首先采用MTT方法确定IL 6作用于U2 6 6后所产生的与细胞生长相关的生物学效应 ;继而采用凝胶阻滞电泳 (electrophoreticmobilityshiftassay ,EMSA)方法观察参与IL 6信号转导功能的转录因子STAT3和NF IL 6在U2 6 6细胞中的诱导激活状态 ,并确定该细胞中的IL 6信号转导途径 ;最后采用PKA途径激动剂 (Forskolin ,FK)与IL 6共同刺激U2 6 6细胞 ,观察IL 6生物学效应和信号转导功能的改变。结果 (1)IL 6可明显促进U2 6 6细胞增殖 ;(2 )两种转录因子分别参与的IL 6信号转导途径 -JAK/STAT和Ras/NF IL 6均能够在U2 6 6细胞中诱导激活 ;(3)FK可抑制U2 6 6细胞本身的生长及IL 6对细胞的增殖促进作用 ,同时下调两条信号途径的活化。结论 U2 6 6细胞中PKA途径激活所介导的IL 6生物学效应减弱与信号转导功能受抑相关。

Objective To study the effects of PKA pathway activation on the biological function and signal transduction of IL 6 in a human myeloma cell line U266. Methods The effect of IL 6 on the growth of U266 cells was shown by MTT; electrophoretic mobility shift assay (EMSA) was used to detect the activation of two transcription factors(TFs) STAT3 and the NF IL 6 by IL 6,which were involved in the JAK/STAT and Ras/NF IL 6 signal transduction pathways. Then, the cells were treated with IL 6 and Forskolin (FK), an agonist of the PKA pathway. The changes in the cell growth and activation of the two TFs were exhibited by MTT and EMSA. Results (1)IL 6 could promote the proliferation of U266 cells, (2)Both JAK/STAT and Ras/NF IL 6 signal transduction pathways were activated by IL 6 in the U266 cells and (3) Cell proliferation and activation of the two IL 6 signal transduction pathways were inhibited by Forskolin; down regulating the actiration of these two signal transduction pathways at the same time. Conclusion The inhibition of cell growth, mediated by the activation of the PKA pathway, is related to the down regulated activation of the two IL 6 signal transduction pathways.