title: Kisspeptin-10-induced signaling of GPR54 negatively regulates chemotactic responses mediated by CXCR4: a potential mechanism for the metastasis suppressor activity of kisspeptins.
abstract: The product of the KiSS-1 gene is absent or expressed at low level in metastatic melanoma and breast cancer compared with their nonmetastatic counterparts. A polypeptide derived from the KiSS-1 product, designated kisspeptin-10 (Kp-10), activates a receptor coupled to Galphaq subunits (GPR54 or KiSS-1R). To study the mechanism by which Kp-10 antagonizes metastatic spread, the effect on CXCR4-mediated signaling, which has been shown to direct organ-specific migration of tumor cells, was determined. Kp-10 blocked chemotaxis of tumor cells expressing CXCR4 in response to low and high concentrations of SDF-1/CXCL12 and inhibited mobilization of calcium ions induced by this ligand. Pretreatment with Kp-10 did not induce down-modulation of cell surface CXCR4 expression, reduce affinity for SDF-1/CXCL12, or alter Galphai subunit activation stimulated by this ligand. Although Kp-10 stimulated prolonged phosphorylation of extracellular signal-regulated kinase 1/2, it inhibited the phosphorylation of Akt induced by SDF-1. The ability of Kp-10 to inhibit signaling and chemotaxis induced by SDF-1 indicates that activation of GPR54 signaling may negatively regulate the role of CXCR4 in programming tumor metastasis.
authors.affiliation: Department of Pathology and Immunotherapy Center, Medical College of Georgia, Augusta, Georgia 30912, USA. jnavenot@mcg.edu
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Navenot
authors.forename: Zixuan
authors.initials: Z
authors.lastname: Wang
authors.forename: Michael
authors.initials: M
authors.lastname: Chopin
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Fujii
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Peiper
mesh_terms: D000818:Animals; D016466:CHO Cells; D002118:Calcium / Q000378:metabolism; D054377:Chemokine CXCL12; D019743:Chemokines, CXC; D002633:Chemotaxis / Q000187:drug effects; D006224:Cricetinae; D004790:Enzyme Induction; D006367:HeLa Cells; D006801:Humans; D059648:Kisspeptins; D020935:MAP Kinase Signaling System / Q000187:drug effects; D020928:Mitogen-Activated Protein Kinases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D009842:Oligopeptides / Q000494:pharmacology*; D051058:Oncogene Protein v-akt / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D010766:Phosphorylation / Q000187:drug effects; D019718:Receptors, CXCR4 / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000502:physiology; D043562:Receptors, G-Protein-Coupled; D000074502:Receptors, Kisspeptin-1; D018013:Receptors, Neuropeptide / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects; D014162:Transfection
chemical_list: C515255:CXCL12 protein, human; D054377:Chemokine CXCL12; D019743:Chemokines, CXC; C106628:KISS1 protein, human; C118688:KISS1R protein, human; D059648:Kisspeptins; D009842:Oligopeptides; D019718:Receptors, CXCR4; D043562:Receptors, G-Protein-Coupled; D000074502:Receptors, Kisspeptin-1; D018013:Receptors, Neuropeptide; D051058:Oncogene Protein v-akt; D020928:Mitogen-Activated Protein Kinases; D002118:Calcium