title: Cannabidiol-induced apoptosis in human leukemia cells: A novel role of cannabidiol in the regulation of p22phox and Nox4 expression.
abstract: In the current study, we examined the effects of the nonpsychoactive cannabinoid, cannabidiol, on the induction of apoptosis in leukemia cells. Exposure of leukemia cells to cannabidiol led to cannabinoid receptor 2 (CB2)-mediated reduction in cell viability and induction in apoptosis. Furthermore, cannabidiol treatment led to a significant decrease in tumor burden and an increase in apoptotic tumors in vivo. From a mechanistic standpoint, cannabidiol exposure resulted in activation of caspase-8, caspase-9, and caspase-3, cleavage of poly(ADP-ribose) polymerase, and a decrease in full-length Bid, suggesting possible cross-talk between the intrinsic and extrinsic apoptotic pathways. The role of the mitochondria was further suggested as exposure to cannabidiol led to loss of mitochondrial membrane potential and release of cytochrome c. It is noteworthy that cannabidiol exposure led to an increase in reactive oxygen species (ROS) production as well as an increase in the expression of the NAD(P)H oxidases Nox4 and p22(phox). Furthermore, cannabidiol-induced apoptosis and reactive oxygen species (ROS) levels could be blocked by treatment with the ROS scavengers or the NAD(P)H oxidase inhibitors. Finally, cannabidiol exposure led to a decrease in the levels of p-p38 mitogen-activated protein kinase, which could be blocked by treatment with a CB2-selective antagonist or ROS scavenger. Together, the results from this study reveal that cannabidiol, acting through CB2 and regulation of Nox4 and p22(phox) expression, may be a novel and highly selective treatment for leukemia.
authors.affiliation: Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, 6439 Garner's Ferry Road, Columbia, SC 29209, USA. rmckallip@gw.med.sc.edu
authors.forename: Robert J
authors.initials: RJ
authors.lastname: McKallip
authors.forename: Wentao
authors.initials: W
authors.lastname: Jia
authors.forename: Jerome
authors.initials: J
authors.lastname: Schlomer
authors.forename: James W
authors.initials: JW
authors.lastname: Warren
authors.forename: Prakash S
authors.initials: PS
authors.lastname: Nagarkatti
authors.forename: Mitzi
authors.initials: M
authors.lastname: Nagarkatti
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002185:Cannabidiol / Q000494:pharmacology*; D020169:Caspases / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D045304:Cytochromes c / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005260:Female; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D019169:Jurkat Cells; D007938:Leukemia / Q000473:pathology*; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D051336:Mitochondrial Membranes / Q000187:drug effects / Q000378:metabolism; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D043885:Receptor, Cannabinoid, CB2 / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D017382:Reactive Oxygen Species; D043885:Receptor, Cannabinoid, CB2; D002185:Cannabidiol; D045304:Cytochromes c; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C498910:NOX4 protein, human; C086986:CYBA protein, human; D048049:Extracellular Signal-Regulated MAP Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D020169:Caspases