To explore the effects of cannabinoid 2 receptor (CB2) in the development of bone cancer pain in mice.”
The cannabinoid 2 receptor plays an important role in the formation of bone cancer pain.”
“The endocannabinoid system plays a key role in regulating a variety of physiological processes such as appetite control and energy balance, pain perception, and immune responses. Recent studies have implicated the endocannabinoid system in the regulation of bone cell activity and bone remodeling. These studies showed that endogenous cannabinoid ligands, cannabinoid receptors, and the enzymes responsible for ligand synthesis and breakdown all play important roles in bone mass and in the regulation of bone disease. These findings suggest that the endocannabinoid pathway could be of value as a therapeutic target for the prevention and treatment of bone diseases. Here, we review the role of the skeletal endocannabinoid system in the regulation of bone remodeling in health and disease.”
“…a great body of evidence demonstrates the analgesic efficacy of systemically administered CB2 agonists in acute and chronic experimental pain….
The activation of CB2 receptors induces analgesia in experimental models of chronic pain. The present experiments were designed to study whether the activation of peripheral or spinal CB2 receptors relieves thermal hyperalgesia and mechanical allodynia in two models of bone cancer pain.
Spinal CB2 receptors are involved in the antiallodynic effect… in two neoplastic models while peripheral and spinal receptors participate in the antihyperalgesic effects… The use of drugs that activate CB2 receptors could be a useful strategy to counteract bone cancer-induced pain symptoms.”
“CB2 agonists not only produce antinociceptive and anti-inflammatory effects, but also have been shown to increase bone density.”
“Recent reports suggest that sustained opiates can produce paradoxical hyperalgesic actions and enhance bone destruction in a murine model of bone cancer. In contrast, CB(2) selective agonists have been shown to reduce bone loss associated with a model of osteoporosis. Here we tested whether a CB(2) agonist administered over a 7day period inhibits bone cancer-induced pain as well as attenuates cancer-induced bone degradation.”
“Based on the antihyperalgesic effects of CB2 agonists, the lack of potential CNS-induced side effects and their propensity to stimulated bone growth, we addressed whether the sustained selective CB2 agonists… has the potential to alleviate bone cancer-induced pain while maintaining bone integrity in a murine model of bone cancer”.
“These findings suggest a novel therapy for cancer-induced bone pain, bone loss and bone fracture while lacking many unwanted side effects seen with current treatments for bone cancer pain.”
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2871326/
“This study compared the efficacy of a tetrahydrocannabinol:cannabidiol (THC:CBD) extract, a nonopioid analgesic endocannabinoid system modulator, and a THC extract, with placebo, in relieving pain in patients with advanced cancer. This study shows that THC:CBD extract is efficacious for relief of pain in patients with advanced cancer pain not fully relieved by strong opioids.” http://www.ncbi.nlm.nih.gov/pubmed/19896326
“In conclusion, THC:CBD extract, a nonopioid analgesic, endocannabinoid system modulator, has been shown to be a useful adjunctive treatment for relief of pain in patients with advanced cancer who experience inadequate analgesia despite chronic opioid therapy. The reductions in pain scores were neither because of a change in opioid background medications nor because of an increase in use of breakthrough medication. Therefore, we can conclude that the observed reduction in pain scores is attributable to the positive analgesic effects of THC:CBD extract.” http://www.jpsmjournal.com/article/S0885-3924(09)00787-8/fulltext
“Although cannabinoids exhibit a broad variety of anticarcinogenic effects, their potential use in cancer therapy is limited by their psychoactive effects. Here we evaluated the impact of cannabidiol, a plant-derived non-psychoactive cannabinoid, on cancer cell invasion. Using Matrigel invasion assays we found a cannabidiol-driven impaired invasion of human cervical cancer (HeLa, C33A) and human lung cancer cells (A549) that was reversed by antagonists to both CB(1) and CB(2) receptors as well as to transient receptor potential vanilloid 1 (TRPV1). The decrease of invasion by cannabidiol appeared concomitantly with upregulation of tissue inhibitor of matrix metalloproteinases-1 (TIMP-1). Knockdown of cannabidiol-induced TIMP-1 expression by siRNA led to a reversal of the cannabidiol-elicited decrease in tumor cell invasiveness, implying a causal link between the TIMP-1-upregulating and anti-invasive action of cannabidiol. P38 and p42/44 mitogen-activated protein kinases were identified as upstream targets conferring TIMP-1 induction and subsequent decreased invasiveness. Additionally, in vivo studies in thymic-aplastic nude mice revealed a significant inhibition of A549 lung metastasis in cannabidiol-treated animals as compared to vehicle-treated controls.
Altogether, these findings provide a novel mechanism underlying the anti-invasive action of cannabidiol and imply its use as a therapeutic option for the treatment of highly invasive cancers.” http://www.ncbi.nlm.nih.gov/pubmed/19914218
http://www.sciencedirect.com/science/article/pii/S000629520900971X
“Cannabinoids, in addition to having palliative benefits in cancer therapy, have been associated with anticarcinogenic effects. Although the antiproliferative activities of cannabinoids have been intensively investigated, little is known about their effects on tumor invasion.”
“Increased expression of TIMP-1 mediates an anti-invasive effect of cannabinoids. Cannabinoids may therefore offer a therapeutic option in the treatment of highly invasive cancers.”
“There is considerable evidence to suggest an important role for cannabinoids in conferring anticarcinogenic activities. In this study, we identified TIMP-1 as a mediator of the anti-invasive actions of MA, a hydrolysis-stable analog of the endocannabinoid anandamide, and THC, a plant-derived cannabinoid.”
“In conclusion, our results suggest that there exists a signaling pathway by which the binding of cannabinoids to specific receptors leads via intracellular MAPK activation to induction of TIMP-1 expression and subsequent inhibition of tumor cell invasion. To our knowledge, this is the first report of TIMP-1–dependent anti-invasive effects of cannabinoids.”
“Studies on the main bioactive components of Cannabis sativa, the cannabinoids, and particularly delta 9-tetrahydrocannabinol (THC), led to the discovery of a new endogenous signalling system that controls several physiological and pathological conditions: the endocannabinoid system. This comprises the cannabinoid receptors, their endogenous agonists–the endocannabinoids–and proteins for endocannabinoid biosynthesis and inactivation.
Recently, evidence has accumulated indicating that stimulation of cannabinoid receptors by either THC or the endocannabinoids influence the intracellular events controlling the proliferation and apoptosis of numerous types of cancer cells, thereby leading to anti-tumour effects both in vitro and in vivo.
This evidence is reviewed here and suggests that future anti-cancer therapy might be developed from our knowledge of how the endocannabinoid system controls the growth and metastasis of malignant cells.”
“The discovery of the endocannabinoid system and the recognition of its potential impact in a plethora of pathological conditions, led to the development of therapeutic agents related to either the stimulation or antagonism of CB1 and CB2 cannabinoid receptors, the majority of which are actually tested in preclinical studies for the pharmacotherapy of several diseases. Endocannabinoid-related agents have been reported to affect multiple signaling pathways and biological processes involved in the development of cancer, displaying an interesting anti-proliferative, pro-apoptotic, anti-angiogenic and anti-metastatic activity both in vitro and in vivo in several models of cancer. Emerging evidence suggests that agonists of cannabinoid receptors, which share the useful property to discern between tumor cells and their non-transformed counterparts, could represent novel tumor-selective tools to treat cancer in addition to their already exploited use as palliative drugs to treat chemotherapy-induced nausea, pain and anorexia/weight loss in cancer patients. The aim of this review is to evidence and update the recent emerging knowledge about the role of the endocannabinoid system in cancer biology and the potentiality of its modulation in cancer therapy.” http://www.ncbi.nlm.nih.gov/pubmed/19559362
http://www.sciencedirect.com/science/article/pii/S1043661809000863