Neuropeptide Y and Its Receptors in Neuroblastoma

OBJECTIVES:

• Determine the expression of neuropeptide Y (NPY) and its receptors (Rs) in human neuroblastoma (NB) tissues.
• Determine whether BDNF/TrkB and TrkAIII stimulate expression of NPY and its Rs.
• Determine whether NPY mediates BDNF- and TrkAIII-induced NB proliferation and survival.
• Determine neurotrophins' angiogenic actions.
• Identify factors released from NB cells upon NPY stimulation (proteomics).
• Determine whether NPY upregulates expression of the identified proteins in NB and their Rs in endothelial cells (ECs).
• Test whether inhibition of the identified pathways reduces angiogenic activity of NB-conditioned media.
• Determine the mechanisms of NYP actions and signaling pathways.
• Test whether blocking NPY-Y2/Y5 pathway reduces NB growth and vascularization in vivo.

OUTLINE: Archived tumor tissue and serum samples are analyzed for neuropeptide Y and its receptors (Y1, Y2, and Y5) expression, neuroblastoma prognostic factors (MYCN, TrkA, TrkAIII, TrkB, BDNF, and NGF), and angiogenic markers by real-time PCR, IHC, ELISA, radioimmunoassay (RIA), mitogenic assay, caspase 3/7 activity assay, western blots, liquid chromatography, tandem mass spectrometry, proteomic assays, and other assays. Results are then analyzed and compared with patients' clinical data, including stage of disease, its phenotype, prognostic markers, age and gender, and response to treatment.