Kuroda H, Sugimoto T, Horii Y, Sawada T
Department of Pediatrics, Miyazaki Medical College, Japan.
Med Pediatr Oncol. 2001 Jan;36(1):118-21. doi: 10.1002/1096-911X(20010101)36:1<118::AID-MPO1028>3.0.CO;2-R.
Ciliary neurotrophic factor (CNTF) is a member of the interleukin-6 (IL-6) cytokine family and affects the survival and differentiation of several classes of neurons. For signal transduction, CNTF requires a receptor complex, composed of the IL-6 signal transducing molecule gp130, leukemia inhibitory factor receptor (LIFR)-beta, and CNTFR-alpha. There are two major independent pathways (Jak-STAT and Ras-MAPK) in cell signaling, and some recent reports show interaction between these pathways. The signal of the IL-6 family is mainly transduced to the Jak-STAT pathway through gp130. However, it has not been examined in neuroblastoma in detail.
Here we examine the signaling pathway of CNTF in 11 neuroblastoma cell lines. Northern blot analysis revealed that 3 of the 11 cell lines expressed c-fos mRNA after CNTF stimulation. Cell lysates were immunoprecipitated with agarose-conjugated antiphosphotyrosine antibody and blotted with anti-gp130, anti-Jak1, or anti-STAT3 antibody. Tyrosine phosphorylation of gp130, Jak1, and STAT3 was observed after CNTF stimulation in these three cell lines. Furthermore, tyrosine phosphorylation of ERK1 (one of the MAPKs) was also observed in all of them.
These results demonstrate that CNTF signaling is conserved in some of the neuroblastoma cell lines and suggest that not only a Jak-STAT pathway but a MAPK pathway is activated by CNTF through gp130 in neuroblastoma cell lines.
睫状神经营养因子（CNTF）是白细胞介素-6（IL-6）细胞因子家族的成员，可影响几类神经元的存活和分化。为了进行信号转导，CNTF需要一个受体复合物，该复合物由IL-6信号转导分子gp130、白血病抑制因子受体（LIFR）-β和CNTFR-α组成。细胞信号传导中有两条主要的独立途径（Jak-STAT和Ras-MAPK），最近的一些报道显示了这些途径之间的相互作用。IL-6家族的信号主要通过gp130转导至Jak-STAT途径。然而，在神经母细胞瘤中尚未对此进行详细研究。
在此，我们检测了11种神经母细胞瘤细胞系中CNTF的信号传导途径。Northern印迹分析显示，11种细胞系中的3种在CNTF刺激后表达c-fos mRNA。用琼脂糖偶联的抗磷酸酪氨酸抗体对细胞裂解物进行免疫沉淀，并用抗gp130、抗Jak1或抗STAT3抗体进行印迹分析。在这三种细胞系中，CNTF刺激后观察到gp130、Jak1和STAT3的酪氨酸磷酸化。此外，在所有这些细胞系中还观察到ERK1（丝裂原活化蛋白激酶之一）的酪氨酸磷酸化。
这些结果表明，CNTF信号传导在一些神经母细胞瘤细胞系中是保守的，并且提示在神经母细胞瘤细胞系中，CNTF不仅通过gp130激活Jak-STAT途径，还激活丝裂原活化蛋白激酶途径。
