(Potential of Cannabinoids in Cancer Therapy) "The use of cannabinoids in medicine is limited by the psychoactive effects mediated by neuronal CB1 receptors (1, 2). Although these adverse effects are within the range of those accepted for other medications, especially in cancer treatment, and tend to disappear with tolerance upon continuous use, it is obvious that cannabinoid-based therapies devoid of side effects would be desirable (3–5). Because glioma cells express functional CB2 receptors (7), we tested the effect of the nonpsychoactive, CB2 receptor-selective agonist JWH-133 and found that it indeed depresses MMP-2 expression in vivo. Likewise, the use of CB receptor type–selective antagonists indicates that CB2 receptors participate in THC-induced inhibition of MMP-2 expression in glioma cells. As selective CB2 receptor activation to mice has been shown to inhibit the growth and angiogenesis of gliomas (11, 13, 27), skin carcinomas (8) and melanomas (15), our observations further support the possibility of finding cannabinoid-based antitumoral strategies devoid of nondesired psychotropic side effects."


Cristina Bla´zquez, Mar?´a Salazar, Arkaitz Carracedo, Mar Lorente, Ainara Egia, Luis Gonza´lez-Feria, Amador Haro, Guillermo Velasco, and Manuel Guzman, "Cannabinoids Inhibit Glioma Cell Invasion by Down-regulating Matrix Metalloproteinase-2 Expression," Cancer Research (March 2008), p. 1951.