Background: Cannabinoid receptors have been detected in human gliomas and cannabinoids
have been proposed as novel drug candidates in the treatment of brain tumors.
Aims: To test the in vitro antitumor activity of COR167, a novel cannabinoid CB2-selective agonist
displaying a high binding affinity for human CB2 receptors, on tumor cells isolated from human
glioblastoma multiforme and anaplastic astrocytoma.
Methods: Glioma cell cultures were established from two glioblastoma multiforme and two anaplastic
astrocytomas. Proliferation was measured in the presence or absence of COR167 with a
bromodeoxyuridine (BrdU) cell proliferation ELISA assay. CB2 receptor expression was detected
by western blotting. Apoptosis was assessed with phycoerythrin (PE) annexin V flow cytometry
kit. TGF-beta 1 and 2 levels were analyzed in culture supernatants with commercial ELISAs.
Results: COR167 was found to significantly reduce the proliferation of both glioblastoma and anaplastic
astrocytoma in a dose-dependent manner at lower doses than other known, less specific
CB2 agonists. This activity is independent of apoptosis and is associated with a significant reduction
of TGF-beta 1 and 2 levels in supernatants of glioma cell cultures.
Conclusion: These findings add to the role of cannabinoid CB2 receptor as a possible pharmacological
target to counteract glial tumor growth and encourage further work to explore any other
pharmacological effect of this novel CB2 agonist useful in the treatment of human gliomas.