Somatostatin receptor biology in neuroendocrine and pituitary tumours: part 1--molecular pathways.
Bottom Line: Like most endocrine tumours, NETs also express somatostatin (SST) receptors (subtypes 1-5) whose ligand SST is known to inhibit endocrine and exocrine secretions and have anti-tumour effects.SST is a potent anti-proliferative and anti-secretory agent for some NETs.Further studies will focus on critical points of SSTR biology such as homo- and heterodimerization of SSTRs and the differences between post-receptor signalling pathways of SSTR subtypes.
Affiliation: Selcuk University, Meram School of Medicine, Division of Endocrinology and Metabolism, Konya, Turkey. email@example.comShow MeSH
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Mentions: The anti-proliferative action of SST-activated PTPs depends on altered growth factor signalling through the selective dephosphorylation and inactivation of their receptors, plus inhibition of one of the most important MAPK pathways for cell proliferation, namely the extracellular signal-regulated protein kinase 1/2 (ERK 1/2) pathway (Fig. 1), and control of the activity of another important downstream signalling pathway, PI3K/Akt (Fig. 2) . The inhibition of the ERK 1/2 pathway can occur either indirectly via the inhibition of the growth factor tyrosine kinase receptors or directly by dephosphorylating ERK 1/2 or by hyperactivation of ERK 1/2 (see below) [102, 103]. Such altered growth factor signalling through the selective dephosphorylation and inactivation of their receptors have been reported for SHP-1 with the insulin receptor, for SHP-2 with the insulin, EGF and platelet-derived growth factor (PDGF) receptor [104–107], for DEP-1 with PDGF and the vascular endothelial growth factor receptor [108, 109] and for PTP1B with the EGF receptor .
Affiliation: Selcuk University, Meram School of Medicine, Division of Endocrinology and Metabolism, Konya, Turkey. firstname.lastname@example.org