title: Fatty acid amide hydrolase inhibitors confer anti-invasive and antimetastatic effects on lung cancer cells.
abstract: Inhibition of endocannabinoid degradation has been suggested as tool for activation of endogenous tumor defense. One of these strategies lies in blockade of fatty acid amide hydrolase (FAAH) which catalyzes the degradation of endocannabinoids (anandamide [AEA], 2-arachidonoylglycerol [2-AG]) and endocannabinoid-like substances (N-oleoylethanolamine [OEA], N-palmitoylethanolamine [PEA]). This study addressed the impact of two FAAH inhibitors (arachidonoyl serotonin [AA-5HT], URB597) on A549 lung cancer cell metastasis and invasion. LC-MS analyses revealed increased levels of FAAH substrates (AEA, 2-AG, OEA, PEA) in cells incubated with either FAAH inhibitor. In athymic nude mice FAAH inhibitors were shown to elicit a dose-dependent antimetastatic action yielding a 67% and 62% inhibition of metastatic lung nodules following repeated administration of 15 mg/kg AA-5HT and 5 mg/kg URB597, respectively. In vitro, a concentration-dependent anti-invasive action of either FAAH inhibitor was demonstrated, accompanied with upregulation of tissue inhibitor of matrix metalloproteinases-1 (TIMP-1). Using siRNA approaches, a causal link between the TIMP-1-upregulating and anti-invasive action of FAAH inhibitors was confirmed. Moreover, knockdown of FAAH by siRNA was shown to confer decreased cancer cell invasiveness and increased TIMP-1 expression. Inhibitor experiments point toward a role of CB2 and transient receptor potential vanilloid 1 in conferring anti-invasive effects of FAAH inhibitors and FAAH siRNA. Finally, antimetastatic and anti-invasive effects were confirmed for all FAAH substrates with AEA and OEA causing a TIMP-1-dependent anti-invasive action. Collectively, the present study provides first-time proof for an antimetastatic action of FAAH inhibitors. As mechanism of its anti-invasive properties an upregulation of TIMP-1 was identified.
authors.affiliation: Institute of Toxicology and Pharmacology, Rostock University Medical Center, Rostock, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Winkler
authors.affiliation: Institute of Toxicology and Pharmacology, Rostock University Medical Center, Rostock, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Ramer
authors.affiliation: Institute of Toxicology and Pharmacology, Rostock University Medical Center, Rostock, Germany.
authors.forename: Sophie
authors.initials: S
authors.lastname: Dithmer
authors.affiliation: Institute of Toxicology and Pharmacology, Rostock University Medical Center, Rostock, Germany.
authors.forename: Igor
authors.initials: I
authors.lastname: Ivanov
authors.affiliation: Institute of Toxicology and Pharmacology, Rostock University Medical Center, Rostock, Germany.
authors.forename: Jutta
authors.initials: J
authors.lastname: Merkord
authors.affiliation: Institute of Toxicology and Pharmacology, Rostock University Medical Center, Rostock, Germany.
authors.forename: Burkhard
authors.initials: B
authors.lastname: Hinz
mesh_terms: D000368:Aged; D000581:Amidohydrolases / Q000037:antagonists & inhibitors*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001095:Arachidonic Acids / Q000494:pharmacology*; D001549:Benzamides / Q000494:pharmacology*; D014408:Biomarkers, Tumor / Q000378:metabolism; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000556:secondary; D002219:Carbamates / Q000494:pharmacology*; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D043885:Receptor, Cannabinoid, CB2 / Q000378:metabolism; D012701:Serotonin / Q000031:analogs & derivatives* / Q000494:pharmacology; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays; D000099252:Fatty Acid Amide Hydrolases
chemical_list: D000581:Amidohydrolases; D001095:Arachidonic Acids; D001549:Benzamides; D014408:Biomarkers, Tumor; D002219:Carbamates; D043885:Receptor, Cannabinoid, CB2; D012701:Serotonin; D019715:Tissue Inhibitor of Metalloproteinase-1; D000099252:Fatty Acid Amide Hydrolases; C560822:TIMP1 protein, human; C114007:arachidonoylserotonin; C500528:cyclohexyl carbamic acid 3'-carbamoylbiphenyl-3-yl ester
keywords: FAAH inhibitors; endocannabinoids; human lung cancer cells; invasion; metastasis