Endocannabinoids are now emerging as suppressors of key cell-signaling pathways involved in
cancer cell growth, invasion, and
metastasis. We have previously observed that the metabolically stable
anandamide analog,
2-methyl-2'-F-anandamide (
Met-F-AEA) can inhibit the growth of
thyroid cancer in vivo. Our hypothesis was that the anti-
tumor effect observed could be at least in part ascribed to inhibition of neo-angiogenesis. Therefore, the aim of this study was to assess the anti-angiogenic activity of
Met-F-AEA, to investigate the molecular mechanisms underlying this effect and whether
Met-F-AEA could antagonize
tumor-induced endothelial cell sprouting. We show that
Met-F-AEA inhibited bFGF-stimulated endothelial cell proliferation, in a dose-dependent manner, and also induced apoptosis, both effects reliant on
cannabinoid CB1 receptor stimulation. Analyzing the signaling pathways implicated in angiogenesis, we observed that the bFGF-induced ERK phosphorylation was antagonized by
Met-F-AEA, and we found that
p38 MAPK was involved in
Met-F-AEA-induced apoptosis. Moreover,
Met-F-AEA was able to inhibit bi-dimensional capillary-like tube formation and activity of matrix
metalloprotease MMP-2, a major matrix degrading
enzyme. Importantly, we demonstrated that
Met-F-AEA is also functional in vivo since it inhibited angiogenesis in the chick chorioallantoic neovascularization model. Finally,
Met-F-AEA inhibited
tumor-induced angiogenesis in a three-dimensional model of endothelial and thyroid
tumor cell (KiMol) spheroids co-cultures in different 3-D polymeric matrices that resemble tumor microenvironment and architecture. Thus, our results suggest that
anandamide could be involved in the control of
cancer growth targeting both
tumor cell proliferation and the angiogenic stimulation of the vasculature.