Immuno-Grade Somatostatin Receptor 2 Antibody

The somatostatin receptor subtype 2 (SST2, SSTR2) is a class A G protein-coupled receptor (GPCR) that is activated by the endogenous peptides somatostatin-14 and somatostatin-28. SST2 primarily couples to Gi/o proteins, leading to inhibition of adenylyl cyclase, reduced intracellular cAMP levels, activation of G protein-gated inwardly rectifying potassium channels, inhibition of voltage-gated calcium channels, and stimulation of protein tyrosine phosphatases. The receptor is highly expressed in the pituitary gland, pancreas, gastrointestinal tract, adrenal gland, and throughout the central nervous system, and is strongly overexpressed in many neuroendocrine tumors (NETs). Functionally, SST2 is the principal mediator of somatostatin-induced inhibition of hormone secretion, including growth hormone, insulin, glucagon, gastrin, and several gastrointestinal peptides, and it also regulates neurotransmission, cell proliferation, apoptosis, and angiogenesis. SST2 is the most clinically important somatostatin receptor subtype and the primary target for the treatment and imaging of neuroendocrine tumors and acromegaly. Several approved drugs, including octreotide, lanreotide, and pasireotide, activate SST2, although pasireotide exhibits the highest affinity for SST5. In addition, the radiolabeled SST2-targeting analogs ^68Ga-DOTATATE, ^68Ga-DOTATOC, ^177Lu-DOTATATE (Lutathera®), and ^90Y-DOTATOC are widely used for molecular imaging and peptide receptor radionuclide therapy (PRRT) of SST2-positive neuroendocrine tumors.