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.

The Endocannabinoid System: A Target for Cancer Treatment

“…More recently, Winkler et al investigated the impact of two FAAH inhibitors (URB597, AA-5HT) and four FAAH substrates (AEA, 2-AG, OEA, PEA) on lung cancer cells spreading. FAAH inhibitors were shown to confer anti-invasive effects via the up-regulation of the matrix metalloproteinase inhibitor TIMP-1 and FAAH substrates mimicked the anti-invasive action of FAAH inhibitors, in agreement with previous evidence [17]. Similar results were obtained with the synthetic cannabinoids JWH-015 and WIN-55,212-2, CB2 and CB1/CB2 agonists, respectively, that from 0.1 to 2 µM significantly inhibited EGF-or serum-induced proliferation and were also able to confer rounded cellular shape, thus inhibiting migration and invasion of NSCLC cell lines and tumor growth and dissemination in murine models.…”

“…URB597 showed a potent antiproliferative effect used in combination with AEA (or Met-F-AEA) in neuroblastoma, lung, and colon cancer, or combination with PEA in melanoma cancer cells [5]. In lung cancer, both AA-5HT and URB597 contrast tumor invasion through TIMP-1 upregulation, likely in a CB2-and TRPV1-dependent way [17]. The MAGL inhibitor JZL184, inhibiting proliferation and tumor cell invasion, induces apoptosis in colon and prostate cancer [18,19].…”

Cannabinoids in cancer treatment: Therapeutic potential and legislation

“…A study investigating the combination of the synthetic analogue of AEA Met-F-AEA and the selective irreversible carbamate-based FAAH inhibitor URB597 showed that they synergistically inhibited epidermal growth factor (EGF)-induced proliferative and chemotactic activity of nonsmall cell lung cancer cell lines A549 and H460 [77]. Moreover, the two FAAH inhibitors URB597 and arachidonoyl serotonin (AA-5HT) had antimetastatic effects on A549 lung cancer cell metastasis [78]. However, recently in France, the first-in-human phase I clinical trial of an experimental FAAH inhibitor BIA 10-2474, for neuropathic pain treatment, ended up tragically; one person died and other four had irreversible brain damage [79,80].…”

A Guide to Targeting the Endocannabinoid System in Drug Design

“…Concerning eCBs, they generally exert tumor-suppressive effect, based on clinical observations [272]. In vitro, AEA was demonstrated to decrease invasion and metastasis by upregulating a tissue inhibitor of matrix metalloproteinases-1 (TIMP-1) [273] and to induce apoptosis via oxidative stress in COX-2- [274] and TRPV1-dependent manner [275]. 2-AG (20 mg/kg/day) showed similar properties in the rodent model, at the same time suppressing tumor immune-mediated surveillance [276].…”