Signal transduction pathways through TRK-A and TRK-B receptors in human neuroblastoma cells.
Little is known about the signal transduction pathways of TRK family receptors in neuroblastoma (NB) cells. In this study, an NB cell line, designated MP-N-TS, was established from an adrenal tumor taken from a 2-year-old boy. This cell line expressed both TRK-A and TRK-B receptors, which is rare in a single NB cell line. Therefore, the MP-N-TS cell line was used to determine whether the signal transduction through these constitutive receptors is functional. Three neurotrophins, nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neurotrophin-4 / 5 (NT-4 / 5), induced tyrosine phosphorylation of panTRK, and BDNF and NT-4 / 5 induced tyrosine phosphorylation of TRK-B. Tyrosine phosphorylation of panTRK and / or TRK-B by the neurotrophins was inhibited in the presence of a tyrosine kinase inhibitor K252a. Tyrosine phosphorylation of Src homologous and collagen (Shc), extracellular signal-regulated kinase (ERK)-1 and ERK-2, and phospholipase C-gamma1 (PLC-gamma1) was increased by the three neurotrophins and the increase was inhibited in the presence of K252a. Activation of Ras, detected as the GTP-bound form of Ras, was induced by the three neurotrophins. The neurotrophins did not modulate the expressions of TRK-A or TRK-B mRNA, but they did induce the expression of c-fos mRNA. Exogenous NGF induced weak neurite outgrowth, whereas exogenous BDNF and NT-4 / 5 induced distinct neurite outgrowth. Exogenous BDNF and NT-4 / 5 increased the number of viable cells, while NGF did not. Our results demonstrate that the signal transduction pathways through TRK-A and TRK-B in MP-N-TS cells are functional and similar, and the main downstream signaling pathways from the three neurotrophins are mitogen-activated protein kinase (MAPK) cascades through Shc, activated Ras, ERK-1 and ERK-2, and the transduction pathway through PLC-gamma1. Further, BDNF and NT-4 / 5 increased cell viability. The MP-N-TS cell line should be useful for clarifying the TRK-A and TRK-B signaling pathways responsible for the different prognoses in patients with NB.
Department of Pediatrics, Kyoto Prefectural University of Medicine, Hirokoji, Kawaramachi, Kamigyo-ku, Kyoto 602-8566, Japan. tosugimo@koto.kpu-m.ac.jp
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Sugimoto
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Kuroda
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Horii
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Moritake
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Tanaka
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Hattori
D000310:Adrenal Gland Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D000818:Animals; D002227:Carbazoles / Q000494:pharmacology; D002454:Cell Differentiation; D002470:Cell Survival; D002675:Child, Preschool; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D026121:Indole Alkaloids; D007700:Kinetics; D008297:Male; D009414:Nerve Growth Factors / Q000494:pharmacology; D009447:Neuroblastoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D016716:PC12 Cells; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis / Q000235:genetics; D016283:Proto-Oncogene Proteins p21(ras) / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D020917:Receptor, trkA / Q000235:genetics / Q000378:metabolism*; D020813:Receptor, trkB / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014407:Tumor Cells, Cultured
D002227:Carbazoles; D004791:Enzyme Inhibitors; D026121:Indole Alkaloids; D009414:Nerve Growth Factors; D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger; D019000:Phosphotyrosine; C049985:staurosporine aglycone; D020917:Receptor, trkA; D020813:Receptor, trkB; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)