CNTF

Gene Summary

Gene:CNTF; ciliary neurotrophic factor
Aliases: HCNTF
Location:11q12.2
Summary:The protein encoded by this gene is a polypeptide hormone whose actions appear to be restricted to the nervous system where it promotes neurotransmitter synthesis and neurite outgrowth in certain neuronal populations. The protein is a potent survival factor for neurons and oligodendrocytes and may be relevant in reducing tissue destruction during inflammatory attacks. A mutation in this gene, which results in aberrant splicing, leads to ciliary neurotrophic factor deficiency, but this phenotype is not causally related to neurologic disease. A read-through transcript variant composed of the upstream ZFP91 gene and CNTF sequence has been identified, but it is thought to be non-coding. Read-through transcription of ZFP91 and CNTF has also been observed in mouse. [provided by RefSeq, Oct 2010]
Databases:OMIM, VEGA, HGNC, Ensembl, GeneCard, Gene
Protein:ciliary neurotrophic factor
HPRD
Source:NCBIAccessed: 27 February, 2015

Ontology:

What does this gene/protein do?
Show (31)
Pathways:What pathways are this gene/protein implicaed in?
Show (2)

Cancer Overview

Research Indicators

Publications Per Year (1990-2015)
Graph generated 27 February 2015 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

  • Receptor Protein-Tyrosine Kinases
  • Lymphokines
  • Phosphorylation
  • Retinoic Acid
  • Childhood Cancer
  • Epigenetics
  • FGF2
  • DNA-Binding Proteins
  • bcl-2-Associated X Protein
  • Cancer Stem Cells
  • Cell Division
  • Chromosome 11
  • Growth Inhibitors
  • Leukemia Inhibitory Factor
  • Receptors, Nerve Growth Factor
  • Brain Tumours
  • Neuroblastoma
  • Base Sequence
  • Tyrosine 3-Monooxygenase
  • Choline O-Acetyltransferase
  • Gene Expression
  • Promoter Regions
  • RTPCR
  • Nerve Growth Factors
  • Messenger RNA
  • Up-Regulation
  • Interleukin-6
  • Proto-Oncogene Proteins
  • Pituitary Tumors
  • Bone Morphogenetic Proteins
  • Gene Expression Regulation
  • Cancer Gene Expression Regulation
  • NTRK1
  • Receptor, Ciliary Neurotrophic Factor
  • Transcription Factors
  • Brain Tumours
  • Cell Differentiation
  • Nerve Tissue Proteins
  • Signal Transduction
  • Ciliary Neurotrophic Factor
  • Sequence Deletion
Tag cloud generated 27 February, 2015 using data from PubMed, MeSH and CancerIndex

Specific Cancers (3)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: CNTF (cancer-related)

Tuupanen S, Hänninen UA, Kondelin J, et al.
Identification of 33 candidate oncogenes by screening for base-specific mutations.
Br J Cancer. 2014; 111(8):1657-62 [PubMed] Article available free on PMC after 14/10/2015 Related Publications
BACKGROUND: Genes with recurrent codon-specific somatic mutations are likely drivers of tumorigenesis and potential therapeutic targets. Hypermutable cancers may represent a sensitive system for generation and selection of oncogenic mutations.
METHODS: We utilised exome-sequencing data on 25 sporadic microsatellite-instable (MSI) colorectal cancers (CRCs) and searched for base-specific somatic mutation hotspots.
RESULTS: We identified novel mutation hotspots in 33 genes. Fourteen genes displayed mutations in the validation set of 254 MSI CRCs: ANTXR1, MORC2, CEP135, CRYBB1, GALNT9, KRT82, PI15, SLC36A1, CNTF, GLDC, MBTPS1, OR9Q2, R3HDM1 and TTPAL. A database search found examples of the hotspot mutations in multiple cancer types.
CONCLUSIONS: This work reveals a variety of new recurrent candidate oncogene mutations to be further scrutinised as potential therapeutic targets.

Zhao X, Qu Z, Tickner J, et al.
The role of SATB2 in skeletogenesis and human disease.
Cytokine Growth Factor Rev. 2014; 25(1):35-44 [PubMed] Related Publications
Since the discovery of SATB2 (special AT-rich sequence binding protein 2) a decade ago, its pivotal roles in development and tissue regeneration have emerged, particularly in craniofacial patterning and development, palate formation, and osteoblast differentiation and maturation. As a member of the special AT-rich binding proteins family that bind to nuclear matrix-attachment regions (MAR), it also displays functional versatility in central nervous development, especially corpus callosum and pons formation, cancer development and prognosis, as well as in immune regulation. At the molecular level, Satb2 gene expression appears to be tissue and stage-specific, and is regulated by several cytokines and growth factors, such as BMP2/4/7, insulin, CNTF, and LIF via ligand receptor signaling pathways. SATB2 mainly performs a twofold role as a transcription regulator by directly binding to AT-rich sequences in MARs to modulate chromatin remodeling, or through association with other transcription factors to modulate the cis-regulation elements and thus to regulate the expression of down-stream target genes and a wide range of biological processes. This contemporary review provides an exploration of the molecular characteristics and function of SATB2; including its expression and cytokine regulation, its involvement in human disease, and its potential roles in skeletogenesis.

Zhang Z, Wang Z, Sun L, et al.
Mutation spectrum and differential gene expression in cystic and solid vestibular schwannoma.
Genet Med. 2014; 16(3):264-70 [PubMed] Related Publications
PURPOSE: We sought to characterize the mutation spectrum of NF2 and the differential gene expression in cystic and solid vestibular schwannomas.
METHODS: We collected tumor tissue and blood samples of 31 cystic vestibular schwannomas and 114 solid vestibular schwannomas. Mutation screening of NF2 was performed in both tumor and blood DNA samples of all patients. cDNA microarray was used to analyze the differential gene expression between 11 cystic vestibular schwannomas and 6 solid vestibular schwannomas. Expression levels of top candidate genes were verified by quantitative reverse transcription PCR.
RESULTS: NF2 mutations were identified in 34.5% of sporadic vestibular schwannomas, with all mutations being exclusively somatic. No significant difference was found between the mutation detection rates of cystic vestibular schwannoma (35.5%) and solid vestibular schwannoma (34.2%). cDNA microarray analysis detected a total of 46 differentially expressed genes between the cystic vestibular schwannoma and solid vestibular schwannoma samples. The significantly decreased expression of four top candidate genes, C1orf130, CNTF, COL4A3, and COL4A4, was verified by quantitative reverse transcription PCR.
CONCLUSION: NF2 mutations are not directly involved in the cystic formation of vestibular schwannoma. In addition, the differential gene expression of cystic vestibular schwannoma reported in our study may provide useful insights into the molecular mechanism underlying this process.

Li X, Li D, Zhuang Y, et al.
Overexpression of miR-708 and its targets in the childhood common precursor B-cell ALL.
Pediatr Blood Cancer. 2013; 60(12):2060-7 [PubMed] Related Publications
BACKGROUND: The critical function of microRNAs in the pathogenesis and prognosis of hematopoietic cancer has become increasingly apparent. However, only a few miRNAs have been reported to be altered in acute lymphocytic leukemia (ALL).
PROCEDURES: To uncover aberrantly expressed miRNAs in pediatric B-cell ALL, our study employed genome-wide miRNA microarray analysis and stem-loop real-time quantitative polymerase chain reaction (qRT-PCR) to examine common precursor B-cell ALL samples. The target genes of miRNA-708 were then identified and verified by bioinformatics, dual-luciferase reporter assay, qRT-PCR, and Western blot.
RESULTS: Significant upregulation of miR-708, miR-210, and miR-181b, and downregulation of miR-345 and miR-27a were observed in common precursor B-cell ALL (common-ALL) samples (P < 0.05). In addition, elevated expression of miR-708 and miR-181b were found in high-risk common-ALL compared to standard and intermediate ones. miR-708 inhibited luciferase reporter activity by binding to the 3'-untranslated regions (3'-UTRs) of CNTFR, NNAT, and GNG12 mRNA in HEK-293 cell line and suppressed the protein levels of CNTFR, NNAT, and GNG12 in Jurkat cells. In addition, mRNA levels of CNTFR and NNAT, but not of GNG12, were found to be downregulated in high risk common-ALL samples. Mutational analysis revealed that miR-708 binds to the 394-400 bp sequence region of the 3'-UTR of CNTFR mRNA.
CONCLUSION: The expression level of miR-708 reflects differences among the clinical types of common-ALL, and CNTFR, NNAT, and GNG12 were identified as targets of miR-708.

Looyenga BD, Resau J, MacKeigan JP
Cytokine receptor-like factor 1 (CRLF1) protects against 6-hydroxydopamine toxicity independent of the gp130/JAK signaling pathway.
PLoS One. 2013; 8(6):e66548 [PubMed] Article available free on PMC after 14/10/2015 Related Publications
Oxidative stress is an important cause of cellular toxicity in the central nervous system and contributes to the pathology associated with neurodegenerative disorders including Parkinson's disease. As such, elucidation of cellular mechanisms that enhance neuronal resistance to oxidative stress may provide new avenues for therapy. In this study we employed a simple two-state cellular model to identify genes that are associated with resistance to oxidative stress induced by 6-hydroxydopamine (6-OHDA). In this model, undifferentiated neuroblastoma cells display higher sensitivity to 6-OHDA than differentiated cells. By comparing the gene expression between these two states, we identified several genes whose expression is altered concomitant with changes in 6-OHDA sensitivity. This gene set includes cytokine receptor-like factor 1 (CRLF1), which is up-regulated during the differentiation process and has been previously implicated in neuroprotection. We show that the product of this gene is both necessary and sufficient for increased resistance to 6-OHDA in differentiated neuroblastoma cells, and that CRLF1 serves its protective role by a cell autonomous mechanism that is independent from its known role as a co-ligand for the ciliary neurotrophic factor receptor. These data provide an additional role for CRLF1 that could potentially explain its broad expression pattern and effects on cells lacking expression of this receptor.

Lu J, Ksendzovsky A, Yang C, et al.
CNTF receptor subunit α as a marker for glioma tumor-initiating cells and tumor grade: laboratory investigation.
J Neurosurg. 2012; 117(6):1022-31 [PubMed] Related Publications
OBJECT: Tumor-initiating cells are uniquely resilient to current treatment modalities and play an important role in tumor resistance and recurrence. The lack of specific tumor-initiating cell markers to identify and target these cells presents a major obstacle to effective directed therapy.
METHODS: To identify tumor-initiating cell markers in primary brain tumors, the authors compared the proteomes of glioma tumor-initiating cells to their differentiated progeny using a novel, nongel/shotgun-based, multidimensional liquid-chromatography protein separation technique. An in vivo xenograft model was used to demonstrate the tumorigenic and stem cell properties of these cells. Western blot and immunofluorescence analyses were used to confirm findings of upregulated ciliary neurotrophic factor receptor subunit-α (CNTFRα) in undifferentiated tumor-initiating cells and gliomas of increasing tumor grade. Sequencing of the CNTFRα coding regions was performed for mutation analysis. Finally, antibody-dependent cell-mediated cytotoxicity was used to establish the role of CNTFRα as a potential immunotherapeutic target.
RESULTS: Ciliary neurotrophic factor receptor subunit-α expression was increased in tumor-initiating cells and was decreased in the cells' differentiated progeny, and expression levels increased with glioma grade. Mutations of CNTFRα are not common in gliomas. Functional studies using CNTF treatment in glioma tumor-initiating cells showed induction of differentiation through the CNTFRα pathway. Treatment with anti-CNTFRα antibody resulted in increased antibody-dependent cell-mediated cytotoxicity in CNTFRα expressing DAOY cells but not in cell lines that lack CNTFRα.
CONCLUSIONS: These data indicate that CNTFRα plays a role in the formation or maintenance of tumor-initiating cells in gliomas, is a marker that correlates with histological grade, may underlie treatment resistance in some cases, and is a potential therapeutic target.

Hirotsu M, Setoguchi T, Matsunoshita Y, et al.
Tumour formation by single fibroblast growth factor receptor 3-positive rhabdomyosarcoma-initiating cells.
Br J Cancer. 2009; 101(12):2030-7 [PubMed] Article available free on PMC after 14/10/2015 Related Publications
BACKGROUND: The hypothesis that malignant tumours are generated by rare populations of cancer stem cells that are more tumourigenic than other cancer cells has gained increasing credence. The objective of this study was to identify and characterise a subpopulation of human sarcoma-initiating cells.
METHODS: We examined established rhabdomyosarcoma cell lines by flow cytometry. Tumourigenesis was examined by xenograft models. Real-time PCR and immunohistochemistry were performed to examine the gene expression using cell lines and biopsy specimens.
RESULTS: Rhabdomyosarcoma cell lines included small populations of fibroblast growth factor receptor 3 (FGFR3)-positive cells. FGFR3-positive KYM-1 and RD cells were more strongly tumourigenic than FGFR3-negative cells. In addition, xenoengraftment of 33% of single FGFR3-positive KYM-1 cells yielded tumour formation. Stem cell properties of FGFR3-positive cells were further established by real-time PCR, which demonstrated upregulation of undifferentiated cell markers and downregulation of differentiation markers. We showed that in the absence of serum, addition of basic fibroblast growth factor maintained and enriched FGFR3-positive cells. On the other hand, ciliary neurotrophic factor reduced the proportion of FGFR3-positive cells. Real-time PCR and immunohistochemical examination revealed that embryonal rhabdomyosarcoma patient biopsy specimens were found to over-express FGFR3.
CONCLUSIONS: Our findings suggest that rhabdomyosarcoma cell lines include a minor subpopulation of FGFR3-positive sarcoma-initiating cells, which can be maintained indefinitely in culture and which is crucial for their malignancy.

Lee J, Son MJ, Woolard K, et al.
Epigenetic-mediated dysfunction of the bone morphogenetic protein pathway inhibits differentiation of glioblastoma-initiating cells.
Cancer Cell. 2008; 13(1):69-80 [PubMed] Article available free on PMC after 14/10/2015 Related Publications
Despite similarities between tumor-initiating cells with stem-like properties (TICs) and normal neural stem cells, we hypothesized that there may be differences in their differentiation potentials. We now demonstrate that both bone morphogenetic protein (BMP)-mediated and ciliary neurotrophic factor (CNTF)-mediated Jak/STAT-dependent astroglial differentiation is impaired due to EZH2-dependent epigenetic silencing of BMP receptor 1B (BMPR1B) in a subset of glioblastoma TICs. Forced expression of BMPR1B either by transgene expression or demethylation of the promoter restores their differentiation capabilities and induces loss of their tumorigenicity. We propose that deregulation of the BMP developmental pathway in a subset of glioblastoma TICs contributes to their tumorigenicity both by desensitizing TICs to normal differentiation cues and by converting otherwise cytostatic signals to proproliferative signals.

Miao T, Wu D, Zhang Y, et al.
SOCS3 suppresses AP-1 transcriptional activity in neuroblastoma cells through inhibition of c-Jun N-terminal kinase.
Mol Cell Neurosci. 2008; 37(2):367-75 [PubMed] Related Publications
Transduction and activation of an inducible form of STAT3 (signal transducer and activator of transcription) sufficed to increase VIP (vasoactive intestinal protein) mRNA concentrations in neuroblastoma cells. Overexpression of SOCS3 (suppressor of cytokine signaling) inhibited and mutant SOCS3 (with an inactivating point mutation in amino acid 25) enhanced the induction of VIP mRNA by CNTF (ciliary neurotrophic factor). Because mutant SOCS3 did not augment the increase in STAT transcriptional activity following CNTF stimulation, the enhancement by mutant SOCS3 of the actions of CNTF cannot be attributed to changes in STAT3 signaling. Mutant SOCS3 increased AP-1 (activator protein) transcriptional activity and JNK (c-Jun N-terminal kinase) activity and SOCS3 bound to the scaffolding protein, JNK-interacting protein-1: these observations provide a plausible explanation for the enhancement by mutant SOCS3 of the actions of CNTF. We conclude that endogenous SOCS3 inhibits AP-1 activity through blocking of JNK phosphorylation.

Katoh M, Katoh M
STAT3-induced WNT5A signaling loop in embryonic stem cells, adult normal tissues, chronic persistent inflammation, rheumatoid arthritis and cancer (Review).
Int J Mol Med. 2007; 19(2):273-8 [PubMed] Related Publications
Leukemia inhibitory factor (LIF), oncostatin M, leptin, ciliary neurotrophic factor, cardiotrophin 1, cardiotrophin-like cytokine factor 1, interleukin 6 (IL6), interleukin 11 and interleukin 27 activate the gp130-JAK-STAT3 signaling cascade. Here, WNT5A was characterized as the evolutionarily conserved target of the STAT3 signaling cascade based on 11-bp-spaced tandem STAT3-binding sites within intron 4 of human, chimpanzee, cow, mouse and rat WNT5A orthologs. Canonical WNT5A signaling through Frizzled and LRP5/LRP6 receptors activates FGF20, WISP1, MYC and CCND1 transcription for the maintenance of stem/progenitor cells, while non-canonical WNT5A signaling through Frizzled and ROR2/PTK7/RYK receptors activates the RHOA, JNK, NLK and NFAT signaling cascades for the control of tissue polarity, cell adhesion or movement. LIF-induced Wnt5a activates canonical Wnt signaling in mouse embryonic stem cells for self-renewal. STAT3-induced Wnt5a activates non-canonical Wnt signaling in rat cardiac myocytes for N-cadherin-dependent aggregation. IL6, secreted from epithelial cells or macrophages, induces WNT5A upregulation in mesenchymal cells. WNT5A then activates canonical WNT signaling in epithelial cells. IL6-induced WNT5A activates canonical WNT signaling for autocrine proliferation of human synovial fibroblasts in rheumatoid arthritis. IL-6 signaling is activated during human chronic atrophic gastritis with Helicobacter pylori infection, and aberrant Stat3 signaling activation gives rise to mouse gastric tumors. WNT5A is frequently upregulated in human primary gastric cancer due to tumor-stromal interaction. WNT5A might be downregulated in advanced cancer with poorer prognosis due to genetic alterations compensating WNT5A signaling. Oncogenic WNT5A activates canonical WNT signaling in cancer stem cells for self-renewal, and non-canonical WNT signaling at the tumor-stromal interface for invasion and metastasis. SNP of genes encoding components of the cytokine-induced WNT5A signaling loop is a predicted risk factor for RA and cancer, especially diffuse-type gastric and pancreatic cancer. Humanized anti-IL6 receptor antibody and WNT5A mimetic small-molecule antagonist could be applied to personalized medicine for RA and cancer driven by the IL6-induced WNT5A signaling loop.

Peterson S, Bogenmann E
The RET and TRKA pathways collaborate to regulate neuroblastoma differentiation.
Oncogene. 2004; 23(1):213-25 [PubMed] Related Publications
Neuroblastoma (NB) is a childhood cancer that arises in the adrenal gland and often shows differentiated neuronal and glial elements. The RET receptor signal pathway is functional in most NB, while loss of nerve growth factor (NGF) receptor (trkA) gene expression correlates with an aggressive phenotype. Thus, we hypothesized that the RET and TRKA signal pathways collaborate to instruct NB differentiation, reminiscent of normal neuronal maturation. Here, we demonstrate that activation of the RET receptor by glial cell line-derived neurotrophic factor (GDNF) increases expression of the RET receptor complex in a panel of malignant human NB cell lines, indicative of a positive feedback mechanism. GDNF also induces growth cessation concomitant with an arrest of cells in the G(0)/G(1) phase of the cell cycle. Furthermore, GDNF synergizes with ciliary neurotrophic factor (CNTF) to enhance TRKA receptor expression, thereby strengthening the NGF-mediated differentiation signal. Differentiated NB cells downregulate expression of the amplified N-myc gene, concurrent with the arrest of cell proliferation, while expressing neuron-specific markers (i.e., SCG10). Interestingly, maintenance of differentiated NB cells in culture is independent of the trophic activity of GDNF, but depends on TRKA signaling, thereby re-enacting the differentiation of normal sympathoadrenal (SA) progenitor cells.

Kaur N, Kim IJ, Higgins D, Halvorsen SW
Induction of an interferon-gamma Stat3 response in nerve cells by pre-treatment with gp130 cytokines.
J Neurochem. 2003; 87(2):437-47 [PubMed] Related Publications
Many cytokines mediate their effects through Jak/STAT signaling pathways providing many opportunities for cross-talk between different cytokines. We examined the interaction between two cytokine families, gp130-related cytokines and interferon-gamma (IFN-gamma), which are coexpressed in the nervous system during acute trauma and pathological conditions. Typical nerve cells show an IFN-gamma response that is restricted to activating STAT1, with minor activation of STAT3. IFN-gamma elicited a pronounced STAT3 response in cells pre-treated for 5-7 h with ciliary neurotrophic factor (CNTF), leukemia inhibitory factor or interleukin-6. CNTF or interleukin-6 induced an IFN-gamma STAT3 response in a variety of cells including SH-SY5Y human neuroblastoma, HMN-1 murine motor neuron hybrid cells, rat sympathetic neurons and human hepatoma HepG2 cells. The enhancement was measured as an increase in tyrosine phosphorylated STAT3, in STAT3-DNA binding and in STAT-luciferase reporter gene activity. The enhanced STAT3 response was not due to an increase in overall STAT3 levels but was dependent upon ongoing protein synthesis. The induction by CNTF was inhibited by the protein kinase C inhibitor, BIM, and the MAPK-kinase inhibitor, U0126. Further, H-35 hepatoma cells expressing gp130 receptor chimeras lacking either the SHP-2 docking site or the Box 3 STAT binding sites failed to enhance the IFN-gamma STAT3 response. These results provide evidence for an interaction between gp130 and IFN-gamma cytokines that can significantly alter the final cellular response to IFN-gamma.

Murata T, Hikita K, Tsuboi M, et al.
Temperature-dependent, neurotrophic factor-elicited, neuronal differentiation in adrenal chromaffin cell line immortalized with temperature-sensitive SV40 T-antigen.
J Neurochem. 2003; 85(5):1126-38 [PubMed] Related Publications
We established adrenal medullary cell lines from transgenic mice expressing an oncogene, the temperature-sensitive simian virus 40 large T-antigen, under the control of the tyrosine hydroxylase promoter. A clonal cell line, named tsAM5D, conditionally grew at a permissive temperature of 33 degrees C and exhibited the dopaminergic chromaffin cell phenotype as exemplified by the expression pattern of mRNA for catecholamine-synthesizing enzymes and secretory vesicle-associated proteins. tsAM5D cells proliferated at the permissive temperature in response to basic fibroblast growth factor (bFGF) and ciliary neurotrophic factor (CNTF). At a non-permissive temperature of 39 degrees C, bFGF and CNTF acted synergistically to differentiate tsAM5D cells into neuron-like cells. In addition, tsAM5D cells caused to differentiate by bFGF plus CNTF at 39 degrees C became dependent solely on nerve growth factor for their survival and showed markedly enhanced neurite outgrowth. In the presence of bFGF and CNTF, the morphological change induced by the temperature shift was associated with up-regulated expression of neuronal marker genes including neuron-specific enolase, growth-associated protein-43, microtubule-associated protein 2, neurofilament, and p75 neurotrophin receptor, indicating that the cells underwent neuronal differentiation. Thus, we demonstrated that tsAM5D cells could proliferate at permissive 33 degrees C, and also had the capacity to terminally differentiate into neuron-like cells in response to bFGF and CNTF when the oncogene was inactivated by shifting the temperature to non-permissive 39 degrees C. These results suggest that tsAM5D cells should be a good tool to allow a detailed study of mechanisms regulating neuronal differentiation.

Dziennis S, Habecker BA
Cytokine suppression of dopamine-beta-hydroxylase by extracellular signal-regulated kinase-dependent and -independent pathways.
J Biol Chem. 2003; 278(18):15897-904 [PubMed] Related Publications
Cholinergic differentiation factors (CDFs) suppress noradrenergic properties and induce cholinergic properties in sympathetic neurons. The CDFs leukemia inhibitory factor (LIF) and ciliary neurotrophic factor (CNTF) bind to a LIFR.gp130 receptor complex to activate Jak/signal transducers and activators of transcription and Ras/mitogen-activated protein kinases signaling pathways. Little is known about how these differentiation factors suppress noradrenergic properties. We used sympathetic neurons and SK-N-BE(2)M17 neuroblastoma cells to investigate CDF down-regulation of the norepinephrine synthetic enzyme dopamine-beta-hydroxylase (DBH). LIF and CNTF activated extracellular signal-regulated kinases (ERKs) 1 and 2 but not p38 or Jun N-terminal kinases in both cell types. Preventing ERK activation with PD98059 blocked CNTF suppression of DBH protein in sympathetic neurons but did not prevent the loss of DBH mRNA. CNTF decreased transcription of a DBH promoter-luciferase reporter construct in SK-N-BE(2)M17 cells, and this was also ERK-independent. Cytokine inhibition of DBH promoter activity did not require a silencer element but was prevented by overexpression of the transcriptional activator Phox2a. Inhibiting ERK activation increased basal DBH transcription in SK-N-BE(2)M17 cells, and DBH mRNA in sympathetic neurons. Transfection of Phox2a into PD98059-treated M17 cells resulted in a synergistic increase in DBH promoter activity compared with Phox2a or PD98059 alone. These data suggest that CDFs down-regulate DBH protein via an ERK-dependent pathway but inhibit DBH gene expression through an ERK-independent pathway. They further suggest that ERK activity inhibits basal DBH gene expression.

Kuroda H, Sugimoto T, Horii Y, Sawada T
Signaling pathway of ciliary neurotrophic factor in neuroblastoma cell lines.
Med Pediatr Oncol. 2001; 36(1):118-21 [PubMed] Related Publications
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.
PROCEDURE AND 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.

Perez Castro C, Carbia Nagashima A, Páez Pereda M, et al.
Effects of the gp130 cytokines ciliary neurotropic factor (CNTF) and interleukin-11 on pituitary cells: CNTF receptors on human pituitary adenomas and stimulation of prolactin and GH secretion in normal rat anterior pituitary aggregate cultures.
J Endocrinol. 2001; 169(3):539-47 [PubMed] Related Publications
Two of the most potent cytokines regulating anterior pituitary cell function are leukemia inhibitory factor (LIF) and interleukin (IL)-6, which belong to the cytokine family using the common gp130 signal transducer. Recently, the expression and action of two other members of this family, IL-11 and ciliary neurotrophic factor (CNTF), on different cell lines has also been demonstrated. We studied the expression of the specific receptor subunits for CNTF in mammotropic, non-functioning and somatotropic tumors and the action of CNTF and IL-11 in the regulation of hormone secretion in these and normal pituitary cells. The mRNA for the alpha chain specific for the CNTF receptor was detected by Northern blot in tumors secreting prolactin (PRL) and GH and in non-functioning tumors. We found that both IL-11 and CNTF exerted a similar stimulatory effect on GH mRNA expression in somatotropic monolayer cell cultures from acromegalic tumors, but these cytokines had no significant influence on GH secretion. CNTF stimulates prolactin secretion in lactotropic monolayer cell cultures from patients with prolactinoma. In monolayer cell cultures from normal rat anterior pituitary, IL-11 and CNTF had no significant effect on the release of either GH or PRL, or on GH mRNA. However, when the cells were cultured in aggregate cultures, in which the three-dimensional structure of the cells is reconstituted, both cytokines, in doses at which they had no effect on monolayer cultures, significantly stimulated both PRL and GH secretion. These data show that IL-11 and CNTF may act as regulatory factors in anterior pituitary cells, in which the three-dimensional structure of the gland is of critical importance.

Tomida M
Structural and functional studies on the leukemia inhibitory factor receptor (LIF-R): gene and soluble form of LIF-R, and cytoplasmic domain of LIF-R required for differentiation and growth arrest of myeloid leukemic cells.
Leuk Lymphoma. 2000; 37(5-6):517-25 [PubMed] Related Publications
The leukemia inhibitory factor receptor (LIF-R) subunit is a component of cell-surface receptor complexes for the multifunctional cytokines, LIF, cardiotrophin-1, ciliary neurotrophic factor, and human oncostatin M. The structure of the human LIF-R gene is similar to that of the mouse gene. The transmembrane receptor is encoded by 19 exons. Two distinct 5' non-coding exons are present, indicating the existence of alternative promoters. An extra-exon specific to the mouse soluble receptor contains a stop codon and polyadenylation signals in a B2 repetitive element. On the other hand, LIF-R mRNAs containing unspliced introns are abundantly present in human tissues. These intronic sequences introduce a termination codon before the transmembrane domain. Human choriocarcinoma cells expressing these mRNAs release soluble LIF-R. The cytoplasmic domain of LIF-R can generate the signals for growth arrest and differentiation of mouse myeloid leukemic cells when they are induced to form a homodimer of the cytoplasmic domain independently of gp130. Two membrane-distal tyrosines on the YXXQ motif of LIF-R are critical not only for STAT3 activation but also for growth arrest and macrophage differentiation of WEHI-3B D+ cells.

Weiss C, Winkler H, Laslop A
Regulation of chromogranin biosynthesis by neurotrophic growth factors in neuroblastoma cells.
Neurochem Int. 2001; 38(1):43-52 [PubMed] Related Publications
Polypeptide growth factors secreted from the target tissue determine the choice of transmitter synthesis in the innervating nerves. We have investigated whether they also influence the expression of chromogranins and neuropeptide Y, components co-stored with the neurotransmitters within large dense-core vesicles. IMR-32 and SH-SY5Y human neuroblastoma cells were treated for up to six days with various neurotrophic growth and differentiation factors. For chromogranins A and B, no significant changes at the mRNA level were observed and for chromogranin A this was confirmed at the protein level. The expression of secretogranin II/pro-secretoneurin mRNA, however, was considerably enhanced in both cell lines after basic fibroblast growth factor treatment. In IMR-32 cells we determined a fast and continuous induction, whereas the up-regulation in SH-SY5Y cells was more delayed. A transient elevation of secretogranin II/pro-secretoneurin mRNA levels was seen in SH-SY5Y cells in response to epidermal growth factor. In these cells we also measured the amounts of secretogranin II/pro-secretoneurin protein which were increased by both growth factors. In addition to the above described changes in secretogranin II/pro-secretoneurin biosynthesis we extended and confirmed data available on neuropeptide Y. We found a qualitatively similar pattern of biosynthesis regulation as for secretogranin II/pro-secretoneurin, indicating that the ultimately increased expression of the two proteins may be characteristic of the phenotypic differentiation after growth factor treatment. Moreover, this finding of a concomitant regulation further emphasizes the concept of secretogranin II/pro-secretoneurin being a neuropeptide precursor from which the functional peptide secretoneurin is proteolytically liberated.

Symes AJ, Pitts RL, Conover J, et al.
Synergy of activin and ciliary neurotrophic factor signaling pathways in the induction of vasoactive intestinal peptide gene expression.
Mol Endocrinol. 2000; 14(3):429-39 [PubMed] Related Publications
Activin, a member of the transforming growth factor-beta superfamily, can regulate neuropeptide gene expression in the nervous system and in neuroblastoma cells. Among the neuropeptide genes whose expression can be regulated by activin is the gene encoding the neuropeptide vasoactive intestinal peptide (VIP). To investigate the molecular mechanisms by which activin regulates neuronal gene expression, we have examined activin's regulation of VIP gene expression in NBFL neuroblastoma cells. We report here that NBFL cells respond to activin by increasing expression of VIP mRNA. Activin regulates VIP gene transcription in NBFL cells through a 180-bp element in the VIP promoter that was previously characterized to be necessary and sufficient to mediate the induction of VIP by the neuropoietic cytokines and termed the cytokine response element (CyRE). We find that the VIP CyRE is necessary and sufficient to mediate the transcriptional response to activin. In addition, ciliary neurotrophic factor (CNTF), a neuropoietic cytokine, synergizes with activin to increase VIP mRNA expression and transcription through the VIP CyRE. Mutations in either the Stat (signal transducer and activator of transcription) or AP-1 sites within the CyRE that reduce the response to CNTF, also reduce the response to activin. However, mutating both the Stat and AP-1 sites within the wild-type CyRE, while reducing the separate responses to either activin or CNTF, eliminates the synergy between them. These data suggest that activin and CNTF, two factors that appear to signal though distinct pathways, activate VIP gene transcription through a common transcriptional element, the VIP CyRE.

Hermanns HM, Radtke S, Haan C, et al.
Contributions of leukemia inhibitory factor receptor and oncostatin M receptor to signal transduction in heterodimeric complexes with glycoprotein 130.
J Immunol. 1999; 163(12):6651-8 [PubMed] Related Publications
Leukemia inhibitory factor (LIF), cardiotrophin-1, ciliary neurotrophic factor, and oncostatin M (OSM) lead to heterodimerization of LIF receptor (LIFR) or the OSM-specific receptor (OSMR) with glycoprotein (gp) 130, the common receptor subunit for IL-6-type cytokines. Thereby intracellular signaling via Janus kinases (Jaks) and STAT transcription factors is initiated. We investigated the contributions of LIFR and OSMR to signal transduction in the context of heterodimers with gp130. Chimeric receptors based on the extracellular parts of the IL-5R alpha- and beta-chains were generated, allowing the induced heterodimerization of two different cytoplasmic tails. Our studies demonstrate that upon heterodimerization with the gp130 cytoplasmic region, the cytoplasmic parts of both LIFR and OSMR were critical for activation of an acute phase protein promoter in HepG2 hepatoma cells. The membrane-proximal region of LIFR or OSMR was crucial for the ability of such receptor complexes to induce DNA binding of STAT1 and STAT3 in COS-7 cells. Membrane-distal regions of LIFR and OSMR contributed to STAT activation even in the absence of gp130 STAT recruitment sites. We further show that the Janus kinases Jak1 and Jak2 constitutively associated with receptor constructs containing the cytoplasmic part of LIFR, OSMR, or gp130, respectively. Homodimers of the LIFR or OSMR cytoplasmic regions did not elicit responses in COS-7 cells but did in HepG2 cells and in MCF-7 breast carcinoma cells. Thus, in spite of extensive functional similarities, differential signaling abilities of gp130, LIFR, and OSMR may become evident in a cell-type-specific manner.

Inui A
Cancer anorexia-cachexia syndrome: are neuropeptides the key?
Cancer Res. 1999; 59(18):4493-501 [PubMed] Related Publications
Progressive wasting is common in many types of cancer and is one of the most important factors leading to early death in cancer patients. Weight loss is a potent stimulus to food intake in normal humans and animals. The persistence of anorexia in cancer patients, therefore, implies a failure of this adaptive feeding response, although the weight loss in the patients differs from that found in simple starvation. Tremendous progress has been made in the last 5 years with regard to the regulation of feeding and body weight. It has been demonstrated that leptin, a hormone secreted by adipose tissue, is an integral component of the homeostatic loop of body weight regulation. Leptin acts to control food intake and energy expenditure via neuropeptidergic effector molecules within the hypothalamus. Complex interactions among the nervous, endocrine, and immune systems affect the loop and induce behavioral and metabolic responses. A number of cytokines, including tumor necrosis factor-alpha, interleukins 1 and 6, IFN-gamma, leukemia inhibitory factor, and ciliary neurotrophic factor have been proposed as mediators of the cachectic process. Cytokines may play a pivotal role in long-term inhibition of feeding by mimicking the hypothalamic effect of excessive negative feedback signaling from leptin. This could be done by persistent stimulation of anorexigenic neuropeptides such as corticotropin-releasing factor, as well as by inhibition of the neuropeptide Y orexigenic network that consists of opioid peptides and galanin, in addition to the newly identified melanin-concentrating hormone, orexin, and agouti-related peptide. Information is being gathered, although it is still insufficient, on such abnormalities in the hypothalamic neuropeptide circuitry in tumor-bearing animals that coincide with the development of anorexia and cachexia. Characterization of the feeding-associated gene products have revealed new biochemical pathways and molecular targets for pharmacological intervention that will likely lead to new treatments. Although therapeutic intervention using neuropeptide agonists/antagonists is now directed at obesity treatment, it may also have an effect on treating cancer anorexia-cachexia, especially when combined with other agents that have effects on muscle and protein breakdown.

McGregor LM, McCune BK, Graff JR, et al.
Roles of trk family neurotrophin receptors in medullary thyroid carcinoma development and progression.
Proc Natl Acad Sci U S A. 1999; 96(8):4540-5 [PubMed] Article available free on PMC after 14/10/2015 Related Publications
Although initiating mutations in the ret protooncogene have been found in familial and sporadic medullary thyroid carcinoma (MTC), the molecular events underlying subsequent tumor progression stages are unknown. We now report that changes in trk family neurotrophin receptor expression appear to be involved in both preneoplastic thyroid C cell hyperplasia and later tumor progression. Only a subset of normal C cells expresses trk family receptors, but, in C cell hyperplasia, the affected cells consistently express trkB, with variable expression of trkA and trkC. In later stages of gross MTC tumors, trkB expression was substantially reduced, while trkC expression was increased and often intense. In a cell culture model of MTC, exogenous trkB expression resulted in severely impaired tumorigenicity and was associated with 11-fold lower levels of the angiogenesis factor vascular endothelial growth factor. These results suggest that trk family receptor genes participate in MTC development and progression, and, in particular, that trkB may limit MTC tumor growth by inhibition of angiogenesis.

Chung TD, Yu JJ, Spiotto MT, et al.
Characterization of the role of IL-6 in the progression of prostate cancer.
Prostate. 1999; 38(3):199-207 [PubMed] Related Publications
BACKGROUND: We recently identified IL-6, a pleiotropic cytokine implicated in the neoplastic process of a variety of neoplasms, as a mediator of prostate cancer morbidity. In the present study, we investigated the expression of members of the IL-6 supergene family and related cytokines and the potential role of IL-6 in prostate cancer growth regulation.
METHODS: Five established human prostate cancer cell lines were screened by ELISA for production of granulocyte colony-stimulating factor (G-CSF), leukemia inhibitory factor (LIF), ciliary neurotrophic factor (CNTF), oncostatin M (OSM), tumor necrosis factor (TNF), interleukin-1 (IL-1), and granulocyte macrophage colony-stimulating factor (GM-CSF). Expression of the ligand-binding component of the IL-6 receptor, IL-6Rp80, was evaluated by ELISA and RT-PCR. Sequential immunoprecipitation and immunoblotting were performed to assay for expression of the signal-transducing component of the IL-6 receptor, gp130. The effects of IL-6 on cell growth were assessed by MTT assays.
RESULTS: The three hormone-refractory cell lines, DU-145, TSU, and PC-3, secreted distinct combinations of cytokines (DU-145: IL-6, GM-CSF; TSU: IL-6, LIF; PC-3: IL-6, G-CSF, LIF, IL-1, GM-CSF), each uniformly expressing IL-6. In contrast, neither of the two hormone-dependent cell lines, LNCaP-ATCC and LNCaP-GW, secreted significant quantities of any of the cytokines analyzed. None of the cell lines secreted detectable quantities of OSM, CNTF, or TNF. All cell lines, irrespective of hormone status, expressed both Il-6Rp80 and gp130. Addition of IL-6 in vitro inhibited growth of hormone-dependent cells, but had no effect on hormone-refractory lines. Anti-IL-6 neutralizing antibody inhibited growth of hormone-refractory cells.
CONCLUSIONS: IL-6 appears to undergo a functional transition from paracrine growth inhibitor to autocrine growth stimulator during progression of prostate cancer to the hormone-refractory phenotype.

Bogenmann E, Peterson S, Maekawa K, Matsushima H
Regulation of NGF responsiveness in human neuroblastoma.
Oncogene. 1998; 17(18):2367-76 [PubMed] Related Publications
Functional nerve growth factor (NGF) responsiveness was investigated in human neuroblastoma (NB) cell lines in vitro and retinoic acid (RA) was found to transcriptionally enhance expression of the trkA, but not the trkB gene in GOTO cells, while the reverse was found in HTLA230 NB cells. Ciliary neurotrophic factor (CNTF) specifically induced trkA gene transcription in both cell lines. Transcriptional activation of the trkA gene increased total trkA protein and surface bound receptor, which was tyrosine phosphorylated upon NGF stimulation inducing immediate early response gene transcription (i.e. c-fos, Egr-1). Newly synthesized trkA protein had a molecular weight of 110 kDa and was post-translationally modified. Rapid down regulation of the receptor protein occurred upon NGF stimulation, despite the presence of high levels of trkA mRNA, due to an increased rate of receptor degradation. Transient DNA synthesis and cell proliferation upon NGF treatment occurred in GOTO cells with elevated trkA expression. In contrast, NGF induced neuronal differentiation in HTLA230 cells expressing the endogenous trkA receptor gene, despite the lack of p75 expression. Hence, transcriptional activation of trkA gene expression can be achieved by different signal pathways in human NB cells, but NGF can act either as mitogen or inducer of cell differentiation, depending on the tumor from which cells are derived.

Halfter H, Kremerskothen J, Weber J, et al.
Growth inhibition of newly established human glioma cell lines by leukemia inhibitory factor.
J Neurooncol. 1998; 39(1):1-18 [PubMed] Related Publications
We have established three new cell lines deriving from malignant human gliomas. The cell lines were described in terms of both morphology and growth characteristics. Most cells in all three cell lines expressed the neuroepithelial marker protein GFAP. In terms of growth characteristics, the cells showed only slight differences. The cell lines showed no expression of the neural form of the c-src gene, pp60c-srcN, but did express the ubiquitous form, pp60c-src. The established glioma cell lines were also examined for expression of members of the neuropoietic cytokine family, CNTF and LIF, and their respective receptor components CNTFRalpha, LIFRbeta and gp130. With the exception of CNTFRalpha both the ligands and their receptor components were expressed in similar amounts in all three cell lines. The presence of ligand and receptor prompted us to study the effects of exogenously supplied factors on the growth of the glioma cell lines. Whereas LIF induced a high c-fos expression, only low c-fos induction was observed upon CNTF treatment. Accordingly, CNTF did not have any noticeable effects on glioma cell growth in culture, while LIF mediated an inhibiting effect on the growth of the three glioma cell lines in culture.

Symes A, Gearan T, Fink JS
NFAT interactions with the vasoactive intestinal peptide cytokine response element.
J Neurosci Res. 1998; 52(1):93-104 [PubMed] Related Publications
The vasoactive intestinal peptide cytokine response element (VIP CyRE) is responsible for mediating the transcriptional induction of the VIP gene to the neuropoietic cytokines leukemia inhibitory factor (LIF) and ciliary neurotrophic factor (CNTF). In investigating the sequence and function of the CyRE, we found a region of DNA with homology to the distal NFAT site in the IL-2 promoter. In this paper we characterize this sequence and show that the VIP NFAT site recognizes T cell NFAT with similar affinity to the previously characterized IL-2 NFAT site. However, despite its location in the middle of the CyRE, we find no CNTF/LIF induced binding to it. Instead we show that in NBFL neuroblastoma cells, the calcium ionophore A23187 induces a protein to bind to the VIP NFAT site. This A23187-mediated induction of nuclear protein binding to an NFAT oligonucleotide is dependent on extracellular calcium but not dependent on de novo protein synthesis. Thus, this protein has the characteristics of an NFAT-like protein and is recognized by an NFAT3-specific antiserum suggesting that it is indeed an NFAT protein. The location of the NFAT site in the VIP CyRE suggests that this may be one mechanism through which different signaling pathways engage in cross talk to alter VIP gene transcription.

Haltia A, Solin ML, Muramatsu T, et al.
Expression of nine developmental stage-specific genes in human kidney and cultured renal cells.
Exp Nephrol. 1997 Nov-Dec; 5(6):457-64 [PubMed] Related Publications
BACKGROUND: Several genes transiently expressed during the maturation of the metanephrogenic mesenchyme have been reported in recent years while there is accumulating evidence of a reverted developmental pathway during tissue damage and loss of function.
METHODS: Here we studied the expression of nine genes associated with kidney maturation from samples of normal human fetal, juvenile and adult kidneys and cultured glomerular cells using Northern blotting analysis. Subsequently, kidneys from patients with congenital nephrotic syndrome of the Finnish type (CNF), presenting with heavy proteinuria, and Wilms' tumor tissue were studied for the corresponding expression pattern for evidence of dedifferentiation/persistence of a fetal expression pattern.
RESULTS: All the genes studied had their distinct expression pattern within the tissues and cells tested. No conclusive evidence of dedifferentiation could be obtained in the samples from CNF kidneys, whereas, as expected, the gene expression pattern of Wilms' tumor tissue was highly similar to that of fetal kidney tissue.
CONCLUSION: Some genes thought to be only transiently expressed during kidney maturation were, however, constantly found in the samples from fetal to newborn and adult kidneys.

Negro A, Onisto M, Pellati D, Garbisa S
CNTF up-regulation of TIMP-2 in neuroblastoma cells.
Brain Res Mol Brain Res. 1997; 48(1):30-6 [PubMed] Related Publications
The ciliary neurotrophic factor (CNTF) can regulate survival and differentiation of many types of developing and adult neurons; in metastatic SK-N-BE neuroblastoma cells, it promotes differentiation and neurite outgrowth. The expression of Gelatinase A (MMP-2) and its specific tissue inhibitor (TIMP-2), a degradative system whose balance is involved in matrix invasion and metastasis, was investigated in SK-N-BE cells cultured with and without CNTF or NGF. Zymographic analysis of conditioned media revealed that the cells constitutively secrete two gelatinases, mainly pro-MMP-2 but also traces of pro-MMP-9. In a time-course experiment in the presence of 25 ng/ml of CNTF, the MMP-2 mRNA expression showed no significant modulation, while TIMP-2 mRNA up-regulated to > 2-fold after 48 h and then fell dramatically. At the same concentrations, NGF showed no effect. TIMP-2 mRNA expression showed a dose-dependent increase of up to 8-fold from 1 to 250 ng/ml of CNTF and increased secretion of TIMP-2 was confirmed by Western blotting. MMP-2 was only slightly over-expressed under the same conditions, at either mRNA or protein level, with no correlation with neurocytokine concentration. These results suggest that boosting the expression of TIMP-2 by CNTF could restrain both matrix degradation following nervous system injury and neuroblastoma aggressiveness.

Gloaguen I, Costa P, Demartis A, et al.
Ciliary neurotrophic factor corrects obesity and diabetes associated with leptin deficiency and resistance.
Proc Natl Acad Sci U S A. 1997; 94(12):6456-61 [PubMed] Article available free on PMC after 14/10/2015 Related Publications
Receptor subunits for the neurocytokine ciliary neurotrophic factor (CNTF) share sequence similarity with the receptor for leptin, an adipocyte-derived cytokine involved in body weight homeostasis. We report here that CNTF and leptin activate a similar pattern of STAT factors in neuronal cells, and that mRNAs for CNTF receptor subunits, similarly to the mRNA of leptin receptor, are localized in mouse hypothalamic nuclei involved in the regulation of energy balance. Systemic administration of CNTF or leptin led to rapid induction of the tis-11 primary response gene in the arcuate nucleus, suggesting that both cytokines can signal to hypothalamic satiety centers. Consistent with this idea, CNTF treatment of ob/ob mice, which lack functional leptin, was found to reduce the adiposity, hyperphagia, and hyperinsulinemia associated with leptin deficiency. Unlike leptin, CNTF also reduced obesity-related phenotypes in db/db mice, which lack functional leptin receptor, and in mice with diet-induced obesity, which are partially resistant to the actions of leptin. The identification of a cytokine-mediated anti-obesity mechanism that acts independently of the leptin system may help to develop strategies for the treatment of obesity associated with leptin resistance.

Brodeur GM, Nakagawara A, Yamashiro DJ, et al.
Expression of TrkA, TrkB and TrkC in human neuroblastomas.
J Neurooncol. 1997; 31(1-2):49-55 [PubMed] Related Publications
There is considerable interest in the role of the TRK family of neurotrophin receptors in regulating the survival, growth and differentiation of normal and neoplastic nerve cells. Indeed, there is increasing evidence that TRK genes play an important role in the biology and clinical behavior of neuroblastomas, tumors of the peripheral nervous system. Evidence from several independent studies suggests that high expression of TrkA is an indicator of favorable outcome, and there is an inverse correlation between TrkA expression and N-myc amplification. In addition, some primary neuroblastomas differentiate in vitro in the presence of NGF but die in its absence. We have evidence that coexpression of full-length TrkB and BDNF is associated with N-myc amplification and may represent an autocrine survival pathway. Conversely, truncated TrkB is expressed predominantly in differentiated tumors. Finally, Trk-C is expressed in favorable neuroblastomas, essentially all of which also express TrkA. In summary, the study of neurotrophin receptor expression and function in neuroblastomas may provide important insights into the role that these pathways play in the pathogenesis and clinical behavior of this tumor. Ultimately, these pathways may provide attractive targets for the development of therapy aimed at inducing differentiation or programmed cell death in these tumors.

Disclaimer: This site is for educational purposes only; it can not be used in diagnosis or treatment.

Cite this page: Cotterill SJ. CNTF, Cancer Genetics Web: http://www.cancer-genetics.org/CNTF.htm Accessed:

Creative Commons License
This page in Cancer Genetics Web by Simon Cotterill is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Note: content of abstracts copyright of respective publishers - seek permission where appropriate.

 [Home]    Page last revised: 27 February, 2015     Cancer Genetics Web, Established 1999