title: (R,R')-4'-methoxy-1-naphthylfenoterol targets GPR55-mediated ligand internalization and impairs cancer cell motility.
abstract: (R,R')-4'-Methoxy-1-naphthylfenoterol (MNF) promotes growth inhibition and apoptosis of human HepG2 hepatocarcinoma cells via cannabinoid receptor (CBR) activation. The synthetic CB1R inverse agonist, AM251, has been shown to block the anti-mitogenic effect of MNF in these cells; however, AM251 is also an agonist of the recently deorphanized, lipid-sensing receptor, GPR55, whose upregulation contributes to carcinogenesis. Here, we investigated the role of MNF in GPR55 signaling in human HepG2 and PANC-1 cancer cell lines in culture by focusing first on internalization of the fluorescent ligand Tocrifluor 1117 (T1117). Initial results indicated that cell pretreatment with GPR55 agonists, including the atypical cannabinoid O-1602 and l-α-lysophosphatidylinositol, dose-dependently reduced the rate of cellular T1117 uptake, a process that was sensitive to MNF inhibition. GPR55 internalization and signaling mediated by O-1602 was blocked by MNF in GPR55-expressing HEK293 cells. Pretreatment of HepG2 and PANC-1 cells with MNF significantly abrogated the induction of ERK1/2 phosphorylation in response to AM251 and O-1602. Moreover, MNF exerted a coordinated negative regulation of AM251 and O-1602 inducible processes, including changes in cellular morphology and cell migration using scratch wound healing assay. This study shows for the first time that MNF impairs GPR55-mediated signaling and, therefore, may have therapeutic potential in the management of cancer.
authors.affiliation: Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health (NIH), Baltimore, MD 21224, USA. Electronic address: paulrk@mail.nih.gov.
authors.forename: Rajib K
authors.initials: RK
authors.lastname: Paul
authors.affiliation: Laboratory of Medicinal Chemistry and Neuroengineering, Department of Chemistry, Medical University of Lublin, 20-093 Lublin, Poland. Electronic address: artur.wnorowski@gmail.com.
authors.forename: Artur
authors.initials: A
authors.lastname: Wnorowski
authors.affiliation: Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health (NIH), Baltimore, MD 21224, USA. Electronic address: isabel.gonzalezmariscal@nih.gov.
authors.forename: Isabel
authors.initials: I
authors.lastname: Gonzalez-Mariscal
authors.affiliation: SRI International (S.K.N.), Harrisonburg, VA 22802, USA. Electronic address: surendra.nayak@sri.com.
authors.forename: Surendra K
authors.initials: SK
authors.lastname: Nayak
authors.affiliation: Laboratory of Medicinal Chemistry and Neuroengineering, Department of Chemistry, Medical University of Lublin, 20-093 Lublin, Poland. Electronic address: karolina.pajak@umlub.pl.
authors.forename: Karolina
authors.initials: K
authors.lastname: Pajak
authors.affiliation: Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health (NIH), Baltimore, MD 21224, USA. Electronic address: moaddelru@grc.nia.nih.gov.
authors.forename: Ruin
authors.initials: R
authors.lastname: Moaddel
authors.affiliation: Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health (NIH), Baltimore, MD 21224, USA. Electronic address: indigfr@grc.nia.nih.gov.
authors.forename: Fred E
authors.initials: FE
authors.lastname: Indig
authors.affiliation: Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health (NIH), Baltimore, MD 21224, USA. Electronic address: bernierm@mail.nih.gov.
authors.forename: Michel
authors.initials: M
authors.lastname: Bernier
authors.affiliation: Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health (NIH), Baltimore, MD 21224, USA. Electronic address: wainerir@grc.nia.nih.gov.
authors.forename: Irving W
authors.initials: IW
authors.lastname: Wainer
mesh_terms: D002465:Cell Movement / Q000187:drug effects* / Q000502:physiology; D054314:Drug Inverse Agonism; D004705:Endocytosis / Q000187:drug effects / Q000502:physiology*; D005280:Fenoterol / Q000008:administration & dosage / Q000031:analogs & derivatives*; D057809:HEK293 Cells; D056945:Hep G2 Cells; D006801:Humans; D008024:Ligands; D058990:Molecular Targeted Therapy / Q000379:methods*; D009369:Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D010880:Piperidines / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism; D011720:Pyrazoles / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism; D043884:Receptor, Cannabinoid, CB1 / Q000819:agonists / Q000502:physiology; D043882:Receptors, Cannabinoid; D043562:Receptors, G-Protein-Coupled / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: C524885:GPR55 protein, human; D008024:Ligands; D010880:Piperidines; D011720:Pyrazoles; D043884:Receptor, Cannabinoid, CB1; D043882:Receptors, Cannabinoid; D043562:Receptors, G-Protein-Coupled; D005280:Fenoterol; C103505:AM 251
keywords: Cell motility; Cellular morphology; G-protein coupled receptor; GPR55; Ligand internalization