title: Peptide receptor targeting in cancer: the somatostatin paradigm.
abstract: Peptide receptors involved in pathophysiological processes represent promising therapeutic targets. Neuropeptide somatostatin (SST) is produced by specialized cells in a large number of human organs and tissues. SST primarily acts as inhibitor of endocrine and exocrine secretion via the activation of five G-protein-coupled receptors, named sst1-5, while in central nervous system, SST acts as a neurotransmitter/neuromodulator, regulating locomotory and cognitive functions. Critical points of SST/SST receptor biology, such as signaling pathways of individual receptor subtypes, homo- and heterodimerization, trafficking, and cross-talk with growth factor receptors, have been extensively studied, although functions associated with several pathological conditions, including cancer, are still not completely unraveled. Importantly, SST exerts antiproliferative and antiangiogenic effects on cancer cells in vitro, and on experimental tumors in vivo. Moreover, SST agonists are clinically effective as antitumor agents for pituitary adenomas and gastro-pancreatic neuroendocrine tumors. However, SST receptors being expressed by tumor cells of various tumor histotypes, their pharmacological use is potentially extendible to other cancer types, although to date no significant results have been obtained. In this paper the most recent findings on the expression and functional roles of SST and SST receptors in tumor cells are discussed.
authors.affiliation: Section of Pharmacology, Department of Internal Medicine and Center of Excellence for Biomedical Research (CEBR), University of Genova, Viale Benedetto XV, 2 16132 Genova, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Barbieri
authors.forename: Adriana
authors.initials: A
authors.lastname: Bajetto
authors.forename: Alessandra
authors.initials: A
authors.lastname: Pattarozzi
authors.forename: Monica
authors.initials: M
authors.lastname: Gatti
authors.forename: Roberto
authors.initials: R
authors.lastname: Würth
authors.forename: Stefano
authors.initials: S
authors.lastname: Thellung
authors.forename: Alessandro
authors.initials: A
authors.lastname: Corsaro
authors.forename: Valentina
authors.initials: V
authors.lastname: Villa
authors.forename: Mario
authors.initials: M
authors.lastname: Nizzari
authors.forename: Tullio
authors.initials: T
authors.lastname: Florio