title: Dual targeting of tumor and endothelial cells by gonadotropin-releasing hormone agonists to reduce melanoma angiogenesis.
abstract: We showed previously that GnRH receptors are expressed in melanoma cells; their activation reduces cell growth and metastatic behavior. Here, we investigated whether GnRH agonists might affect the expression of genes involved in melanoma progression. By genome-wide transcriptomic and real-time PCR analysis, we first observed that GnRH agonists decrease the expression of the pro-angiogenic factor vascular endothelial growth factor (VEGF) (all isoforms) in BLM melanoma cells. Then, we demonstrated that GnRH agonists specifically decrease the expression of the VEGF165 isoform as well as its secretion from BLM cells. These data suggested that activation of GnRH receptors might reduce the pro-angiogenic behavior of melanoma cells. To verify this hypothesis, we treated BLM cells with a GnRH agonist; the conditioned medium from these cells was tested to assess its capability to stimulate human umbilical vein endothelial cell (HUVEC) motility. The migration of HUVECs towards the conditioned medium of GnRH agonist-treated BLM cells was significantly lower than the migration of HUVECs toward the conditioned medium of untreated cells. Thus, GnRH agonists reduce the pro-angiogenic behavior of melanoma cells through a decreased production of bioactive VEGF. We then found that GnRH receptors are also expressed on HUVECs and that GnRH agonists reduce their ability to proliferate and to form capillary-like tubes when stimulated by VEGF. These findings suggest that GnRH agonists exert an anti-angiogenic activity indirectly by decreasing VEGF secretion from tumor cells and directly by counteracting the pro-angiogenic activity of the growth factor. These data might lead to the development of novel targeted approaches for melanoma.
authors.affiliation: Department of Endocrinology, Physiopathology, and Applied Biology, University of Milan, Via Balzaretti 9, 20133 Milan, Italy.
authors.forename: Roberta M
authors.initials: RM
authors.lastname: Moretti
authors.forename: Stefania
authors.initials: S
authors.lastname: Mai
authors.forename: Marina
authors.initials: M
authors.lastname: Montagnani Marelli
authors.forename: Maria R
authors.initials: MR
authors.lastname: Bani
authors.forename: Carmen
authors.initials: C
authors.lastname: Ghilardi
authors.forename: Raffaella
authors.initials: R
authors.lastname: Giavazzi
authors.forename: Deanne M
authors.initials: DM
authors.lastname: Taylor
authors.forename: Paolo G V
authors.initials: PG
authors.lastname: Martini
authors.forename: Patrizia
authors.initials: P
authors.lastname: Limonta
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D016000:Cluster Analysis; D016503:Drug Delivery Systems / Q000379:methods*; D004353:Drug Evaluation, Preclinical; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists*; D006801:Humans; D008545:Melanoma / Q000098:blood supply / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D009389:Neovascularization, Pathologic / Q000188:drug therapy* / Q000473:pathology; D020411:Oligonucleotide Array Sequence Analysis; D017329:Triptorelin Pamoate / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D017329:Triptorelin Pamoate; D007987:Gonadotropin-Releasing Hormone; C066438:deslorelin