Signaling pathway of ciliary neurotrophic factor in neuroblastoma cell lines.
BACKGROUND
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.


RESULTS
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.


CONCLUSIONS
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.
Kuroda
H
H
Department of Pediatrics, Miyazaki Medical College, Japan. kurodah@post.miyazaki-med.ac.jp
Sugimoto
T
T
Horii
Y
Y
Sawada
T
T
D015703:Antigens, CD / Q000502:physiology; D015152:Blotting, Northern; D020934:Ciliary Neurotrophic Factor / Q000494:pharmacology* / Q000502:physiology; D050822:Cytokine Receptor gp130; D004268:DNA-Binding Proteins / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D016762:Genes, fos; D006801:Humans; D053613:Janus Kinase 1; D053680:Leukemia Inhibitory Factor Receptor alpha Subunit; D020935:MAP Kinase Signaling System / Q000187:drug effects; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins / Q000502:physiology; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009363:Neoplasm Proteins / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D009447:Neuroblastoma / Q000378:metabolism / Q000473:pathology*; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis; D020801:Receptor, Ciliary Neurotrophic Factor / Q000187:drug effects / Q000502:physiology*; D018121:Receptors, Cytokine / Q000502:physiology; D053606:Receptors, OSM-LIF; D050796:STAT3 Transcription Factor; D015398:Signal Transduction / Q000187:drug effects*; D015534:Trans-Activators / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism
D015703:Antigens, CD; D020934:Ciliary Neurotrophic Factor; D004268:DNA-Binding Proteins; C494199:IL6ST protein, human; C507840:LIFR protein, human; D053680:Leukemia Inhibitory Factor Receptor alpha Subunit; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; D016760:Proto-Oncogene Proteins c-fos; D020801:Receptor, Ciliary Neurotrophic Factor; D018121:Receptors, Cytokine; D053606:Receptors, OSM-LIF; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D015534:Trans-Activators; D050822:Cytokine Receptor gp130; D011505:Protein-Tyrosine Kinases; C507904:JAK1 protein, human; D053613:Janus Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases