title: Functional activity of CXCL8 receptors, CXCR1 and CXCR2, on human malignant melanoma progression.
abstract: We examined the autocrine/paracrine role of interleukin-8 (CXCL8) and the functional significance of CXCL8 receptors, CXCR1 and CXCR2, in human malignant melanoma proliferation, migration, invasion and angiogenesis. We found that a panel of seven cell lines, even though at different extent, secreted CXCL8 protein, and expressed CXCR1 and CXCR2 independently from the CXCL8 expression, but depending on the oxygen level. In fact, hypoxic exposure increases the expression of CXCR1 and CXCR2. The cell proliferation of both M20 and A375SM lines, expressing similar levels of both CXCR1 and CXCR2 but secreting low and high amounts of CXCL8, respectively, was significantly enhanced by CXCL8 exposure and reduced by CXCL8, CXCR1 and CXCR2 neutralising antibodies, indicating the autocrine/paracrine role of CXCL8 in melanoma cell proliferation. Moreover, an increased invasion and migration in response to CXCL8 was observed in several cell lines, and a further enhancement evidenced under hypoxic conditions. A CXCL8-dependent in vivo vessel formation, evaluated through a matrigel assay, was also demonstrated. Furthermore, when neutralising antibodies against CXCR1 or CXCR2 were used, only the involvement of CXCR2, but not CXCR1 was observed on cell migration and invasion, while both receptors played a role in angiogenesis. In summary, our data demonstrate that CXCL8 induces cell proliferation and angiogenesis through both receptors and that CXCR2 plays an important role in regulating the CXCL8-mediated invasive and migratory behaviour of human melanoma cells. Thus, blocking the CXCL8 signalling axis promises an improvement for the therapy of cancer and, in particular, of metastatic melanoma.
authors.affiliation: Experimental Chemotherapy Laboratory, Regina Elena Cancer Institute, Via delle Messi d'Oro 156, Rome 00158, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Gabellini
authors.forename: Daniela
authors.initials: D
authors.lastname: Trisciuoglio
authors.forename: Marianna
authors.initials: M
authors.lastname: Desideri
authors.forename: Antonio
authors.initials: A
authors.lastname: Candiloro
authors.forename: Ylenia
authors.initials: Y
authors.lastname: Ragazzoni
authors.forename: Augusto
authors.initials: A
authors.lastname: Orlandi
authors.forename: Gabriella
authors.initials: G
authors.lastname: Zupi
authors.forename: Donatella
authors.initials: D
authors.lastname: Del Bufalo
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism*; D008545:Melanoma / Q000098:blood supply / Q000378:metabolism*; D051379:Mice; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000378:metabolism*; D009389:Neovascularization, Pathologic / Q000209:etiology; D023062:Receptors, Interleukin-8A / Q000378:metabolism*; D023063:Receptors, Interleukin-8B / Q000378:metabolism*
chemical_list: C508606:CXCL8 protein, human; D016209:Interleukin-8; D009363:Neoplasm Proteins; D023062:Receptors, Interleukin-8A; D023063:Receptors, Interleukin-8B