In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 30, No. 15_suppl ( 2012-05-20), p. e20008-e20008
Abstract:
e20008 Background: Neuroblastoma is the most common solid tumor found in children and is difficult to treat given its genetic and clinical heterogeneity. The tyrosine kinase receptor, TrkB, is often co-expressed with the MYCN oncogene in high-risk tumors, whereas the TrkA receptor is most often found expressed in low-risk, non-MYCN amplified samples. There are differences in the gene expression profiles of TrkB- and TrkA-over-expressing cell lines, but they do not explain the phenotypic variation. We hypothesize that differences in protein translation and post-translational modifications have profound downstream effects on cellular signaling and disease phenotype. Methods: We performed quantitative proteomics using stable isotope labeling, phosphopeptide enrichment, and tandem mass spectrometry on parental SY5Y neuroblastoma cells and cell lines stably transfected with either TrkA or TrkB. Receptors were activated with NGF or BDNF and activation was inhibited with CEP-701 (Lestaurtinib), a selective tyrosine kinase inhibitor, currently in clinical trials. Samples were separated by gel electrophoresis, digested with trypsin, and applied to the mass spectrometer for protein identification. Results: We have performed quantitative phosphoproteomic analysis and compared protein expression levels and patterns in TrkA overexpressing, TrkB overexpressing, and parental SY5Y cells. The TrkA and TrkB receptors were activated with NGF and BDNF ligands, respectively, as evidenced by increased phosphorylation of ERK and AKT, with inhibition by CEP-701. Changes in protein abundance and pathway activation following both ligand binding and inhibition are being determined by quantitative phosphoproteomic analysis, and TrkA-specific and TrkB-specific differences will be presented. Conclusions: As current genomic techniques may underestimate the differences in protein expression, proteomic profiling holds great promise for describing how post-translational modifications such as phosphorylation can affect tumor phenotype. Our work may reveal key elements of TRK signaling pathways important in neuroblastoma tumorigenesis, and may lead to the identification of novel targets for therapy development.
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/jco.2012.30.15_suppl.e20008
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2012
detail.hit.zdb_id:
2005181-5
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