Simplified diagram of the signaling network between surface receptors and intracellular pathways involved in tumor progression and angiogenesis in pancreatic neuroendocrine tumors, and interaction with mammalian target of rapamycin inhibition and somatostatin analog therapy.
Abbreviations: EGFR, epidermal growth factor receptor; ERK1/2, extracellular signal-regulated protein kinase 1/2; HIF-1α, hypoxia-inducible factor-1α; IGF-1 insulin-like growth factor-1; IGF-1R, insulin-like growth factor-1 receptor; IRS-1, insulin receptor substrate-1; MEK, mitogen-activated protein kinase kinase; mTOR, mammalian target of rapamycin; MTORC1, mammalian target of rapamycin complex-1; mTORC2, mammalian target of rapamycin complex-2; PDGFR, platelet-derived growth factor receptor; PI3K, phosphatidylinositol 3-kinase; PIP3, phosphatidylinositol (3,4,5)-triphosphate; SSTR, somatostatin receptor; VEGF, vascular endothelial growth factor; VEGFR, vascular endothelial growth factor receptor.