Type III TGF-β receptor promotes FGF2-mediated neuronal differentiation in neuroblastoma
Erik H. Knelson, … , Karthikeyan Mythreye, Gerard C. Blobe
Erik H. Knelson, … , Karthikeyan Mythreye, Gerard C. Blobe
Published October 15, 2013
Citation Information: J Clin Invest. 2013;123(11):4786-4798. https://doi.org/10.1172/JCI69657.
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Research Article Oncology

Type III TGF-β receptor promotes FGF2-mediated neuronal differentiation in neuroblastoma

Abstract

Growth factors and their receptors coordinate neuronal differentiation during development, yet their roles in the pediatric tumor neuroblastoma remain unclear. Comparison of mRNA from benign neuroblastic tumors and neuroblastomas revealed that expression of the type III TGF-β receptor (TGFBR3) decreases with advancing stage of neuroblastoma and this loss correlates with a poorer prognosis. Patients with MYCN oncogene amplification and low TGFBR3 expression were more likely to have an adverse outcome. In vitro, TβRIII expression was epigenetically suppressed by MYCN-mediated recruitment of histone deacetylases to regions of the TGFBR3 promoter. TβRIII bound FGF2 and exogenous FGFR1, which promoted neuronal differentiation of neuroblastoma cells. TβRIII and FGF2 cooperated to induce expression of the transcription factor inhibitor of DNA binding 1 via Erk MAPK. TβRIII-mediated neuronal differentiation suppressed cell proliferation in vitro as well as tumor growth and metastasis in vivo. These studies characterize a coreceptor function for TβRIII in FGF2-mediated neuronal differentiation, while identifying potential therapeutic targets and clinical biomarkers for neuroblastoma.

Authors

Erik H. Knelson, Angela L. Gaviglio, Alok K. Tewari, Michael B. Armstrong, Karthikeyan Mythreye, Gerard C. Blobe

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Figure 5

TβRIII enhances FGF2 signaling to promote neuronal differentiation.

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TβRIII enhances FGF2 signaling to promote neuronal differentiation. Cell...
Cells were treated with doses of 10 ng/ml FGF2, 1 μM PD-173074, and 10 μM U0126. (A) Western blot for phosphorylated and total Erk. Differentiation markers after 72-hour TβRIII knockdown and rescue with nontargeted shRNA or shRNA against TβRIII, with or without 1 ng/ml FGF2 treatment (gray bars). Densitometry for pErk normalized to total Erk is shown as percent control. 5Y cells were transduced for 96 hours. Quantification of densitometry from 4 independent experiments is shown (normalized mean ± SEM). P < 0.001 for main effect receptor (2-way ANOVA); P < 0.0001 for main effect FGF2 (2-way ANOVA); interaction P < 0.05. (B) Western blots following 96 hours of TβRIII transduction and treatment. Densitometry for NF160 normalized to β-actin is shown as percent control. (C) Western blots following 96 hours of transduction with TβRIII or GFP control and dominant-negative FGFR1 (dnFGFR1) or IRES-GFP vector control. GFP fluorescence was used to verify construct expression. Densitometry for NF160 normalized to β-actin is shown as percent control.