Fig. 6
Inhibition of the cannabinoid-induced anti-proliferative effect by the CB2 antagonist AM-630. RCC cells (786-O (a) and ACHN (b)) were pre-treated with the concentration (0–25 μM) of antagonist AM-630 or SR141716A for 48 h before treatment with the agonist WIN-55 (10–15 μM). Representative graphs showing that blocking the CB1 receptor with the antagonist SR141716A and treatment with WIN-55 resulted in reduced RCC cell proliferation. However, cells pre-treated with the CB2 receptor antagonist AM-630 followed by WIN-55 treatment did not produce similar results, suggesting the involvement of CB2 in RCC cell proliferation [* p < 0.05 vs control (0 μM)]. c Cytotoxicity percentage of cultured RCC cells resulting from WIN-55 treatment. Graph showing RCC cells (786-O and ACHN) cultured with increase concentration of WIN-55 resulted in increased cytotoxicity based on lactate dehydrogenase (LDH) level. The cytotoxicity percentage was measured of release of LDH using Pierce LDH Cytotoxicity Assay Kit [* p < 0.05 vs control (0 μM)]