Somatostatin is a widely distributed peptide hormone that plays an important inhibitory role in several biological processes, including neurotransmission, exocrine and endocrine secretions, and cell proliferation (Ref.1). Somatostatin acts via a family of five GPCRs (G-Protein-Coupled Receptors): SSTR1-SSTR5 (Somatostatin Receptors) that are variably expressed throughout numerous tissues ranging from the CNS (Central Nervous System) to the Endocrine and Immune Systems. Somatostatin antiproliferative action results either from inhibition of trophic or growth factors secretion or from interference with the normal Cell Cycle Progression. Among the five Somatostatin receptors, SSTR2 (Somatostatin Receptor-2) plays a critical role in the negative control of normal and Tumor cell growth (Ref.2).
The mechanism involved in transmission of the antiproliferative effects of the SSTR2 has been attributed [...]