CB(2) and TRPV(1) receptors mediate cannabinoid actions on MDR1 expression in multidrug resistant cells.
Journal Title: Pharmacological Reports - Year 2012, Vol 64, Issue 3
Abstract
Background: Cannabis is the most widely used illicit drug in the world that is often used by cancer patients in combination with conventional anticancer drugs. Multidrug resistance (MDR) is a major obstacle in the treatment of cancer. An extensively characterized mechanism of MDR involves overexpression of P-glycoprotein (P-gp), which reduces the cellular accumulation of cytotoxic drugs in tumor cells. Methods: Here we examined the role of cannabinoid receptors and transient receptor potential vanilloid type 1 (TRPV(1)) receptors in the effects of plant-derived cannabinoids on MDR1 mRNA expression in MDR CEM/VLB(100) cells which overexpress P-gp due to MDR1 gene amplification. Results: We showed that both cannabidiol (CBD) and Δ(9)-tetrahydrocannabinol (Δ(9)-THC) (10 μM) transiently induced the MDR1 transcript in P-gp overexpressing cells at 4 but not 8 or 48 h incubation durations. CBD and THC also concomitantly increased P-gp activity as measured by reduced accumulation of the P-gp substrate Rhodamine 123 in these cells with a maximal inhibitory effect observed at 4 h that slowly diminished by 48 h. CEM/VLB(100) cell lines were shown to express CB(2) and TRPV(1) receptors. Δ(9)-THC effects on MDR1 expression were mediated by CB(2) receptors. The effects of CBD were not mediated by either CB(2) or TRPV(1) receptors alone, however, required activation of both these receptors to modulate MDR1 mRNA expression. Conclusion: This is the first evidence that CB(2) and TRPV(1) receptors cooperate to modulate MDR1 expression.
Authors and Affiliations
Jonathon Arnold, Phoebe Hone, Michelle Holland, John Allen
Influence of umbelliferone on membrane-bound ATPases in streptozotocin-induced diabetic rats.
The activities of membrane-bound ATPases are altered both in erythrocytes and tissues of streptozotocin (STZ)-induced diabetic rats and diabetic patients. Umbelliferone (UMB), a natural antioxidant, is a benzopyrone occu...
Biological actions of lipoic acid associated with sulfane sulfur metabolism.
This work aimed to investigate the effect of lipoic acid (LA) on sulfane sulfur (S(*)) level and rhodanese activity in rat tissues. In vitro studies conduced so far have indicated that dihydrolipoic acid serves as an S(*...
ERK signalling pathway is not involved in PSA-NCAM-dependent alterations of hippocampal plasticity evoked by CB1 receptor activation.
The present study investigated the potential role of the extracellular signal-regulated kinase (ERK) pathway in the alternation of polysialylated neural cell adhesion molecule (PSA-NCAM) expression and proliferation rate...
Comparison of the effect of 4-hydroxycoumarin and umbelliferone on the phase transition of dipalmitoylphosphatidylcholine (DPPC) bilayers.
The study compares the effect of the addition of two coumarins: 4-hydroxycoumarin (4-HC) and 7-hydroxycoumarin (umbelliferone; UMB) on dipalmitoylphosphatidylcholine (DPPC) membranes. The study was based on microcalorime...
Opposite effects of beta amyloid on endothelial cell survival: role of fibroblast growth factor-2 (FGF-2).
Amyloid beta-peptides (Abeta) aggregate during Alzheimer's disease contributing to the development of the pathology. At micromolar concentration Abeta is toxic and accumulates in neurons and in the vasculature. However,...