title: The NK-1 receptor is expressed in human melanoma and is involved in the antitumor action of the NK-1 receptor antagonist aprepitant on melanoma cell lines.
abstract: Melanoma, the most deadly form of skin cancer, is aggressive and resistant to current therapies. It has been previously reported that the substance P and neurokinin-1 (NK-1) receptor antagonists induce cell proliferation and cell inhibition, respectively, in human melanoma cell lines. Aprepitant is a selective high-affinity antagonist of the human NK-1 receptor. Until now, this drug has been used as an anxiolytic, antidepressant and antiemetic. Moreover, the antitumor action of aprepitant has been previously reported. However, the presence of NK-1 receptors in human melanomas and whether the antitumor action of the NK-1 receptor antagonist aprepitant is exerted on human malignant melanomas have not been previously described. The aims of this study are to show the presence of NK-1 receptors in human malignant melanomas and the antitumoral action of aprepitant against several human melanoma cell lines. Immunoblot analysis was used to determine the presence of NK-1 receptors in human melanoma cell lines, and immunohistochemistry was used to demonstrate NK-1 receptors in human melanoma samples. We performed an in vitro study of the cytotoxicity of the NK-1 receptor antagonist aprepitant on human melanoma cell lines. A coulter counter was used to determine viable cell numbers, followed by application of the tetrazolium compound MTS. The DAPI method was applied to demonstrate apoptosis. We observed that NK-1 receptors were present in all the melanoma samples studied as well as in human melanoma cell lines. We also showed that melanoma cell lines expressed mRNA for the NK-1 receptor. Moreover, after using a knockdown method, we showed that NK-1 receptors are involved in the viability of tumor cells. In this study, we also report that aprepitant, at 10-60 microM concentrations, elicits cell growth inhibition in a concentration-dependent manner in all melanoma cell lines studied, that the specific antitumor action of aprepitant occurs through the NK-1 receptor and that melanoma cell death is due to apoptosis. These findings show for the first time that the NK-1 receptor may be a promising new target and that the NK-1 receptor antagonist aprepitant could be a candidate as a new antitumor drug in the treatment of human melanoma.
authors.affiliation: Research Laboratory on Neuropeptides, Virgen del Rocío University Hospital, Sevilla, Spain. mmunoz@cica.es
authors.forename: Miguel
authors.initials: M
authors.lastname: Muñoz
authors.forename: Marisa
authors.initials: M
authors.lastname: Rosso
authors.forename: María José
authors.initials: MJ
authors.lastname: Robles-Frias
authors.forename: Manuel Vicente
authors.initials: MV
authors.lastname: Salinas-Martín
authors.forename: Rosario
authors.initials: R
authors.lastname: Rosso
authors.forename: Ana
authors.initials: A
authors.lastname: González-Ortega
authors.forename: Rafael
authors.initials: R
authors.lastname: Coveñas
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D000077608:Aprepitant; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D006801:Humans; D008545:Melanoma / Q000378:metabolism / Q000473:pathology*; D009025:Morpholines / Q000494:pharmacology*; D064729:Neurokinin-1 Receptor Antagonists; D018040:Receptors, Neurokinin-1 / Q000378:metabolism* / Q000502:physiology; D012878:Skin Neoplasms; D013373:Substance P / Q000378:metabolism / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D009025:Morpholines; D064729:Neurokinin-1 Receptor Antagonists; D018040:Receptors, Neurokinin-1; D000077608:Aprepitant; D013373:Substance P