Action of CB1 and CB2 antagonists/inverse agonists on mantle cell lymphoma

In this study, the effects of antagonists to the cannabinoid receptors in MCL cell lines were studied. Results presented in this study show that signalling through cannabinoid receptor with antagonists such as SR141716, SR144528 decreases cell viability but hemopressin when analyzing with XTT. The decrease in cell viability by SR141716 is caused by apoptosis triggered after 5 hours of treatment. The CB1 expression was confirmed in all MCL cell lines tested via western blotting but the expression of CB2 and GPR55 – another receptor to which SR141716 has affinity - was not confirmed due to lack of reliable antibodies. Specific agonist to GPR55 – LPI (l-α-lysophosphatidylinositol) showed different response compared to SR141716 which suggests that the effect seen by SR141716 was not induced through GPR55. The effect induced by CB1/CB2 agonist AEA is shown to be neither through CB1 or CB2 alone but possibly on another receptor yet to be described