Cannabis-derived substances in cancer therapy–an emerging anti-inflammatory role for the cannabinoids.
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Category Archives: Colon Cancer
Cannabinoid receptor ligands as potential anticancer agents–high hopes for new therapies?
“OBJECTIVES:
The endocannabinoid system is an endogenous lipid signalling network comprising arachidonic-acid-derived ligands, cannabinoid (CB) receptors, transporters and endocannabinoid degrading enzymes. The CB(1) receptor is predominantly expressed in neurons but is also co-expressed with the CB(2) receptor in peripheral tissues. In recent years, CB receptor ligands, including Delta(9)-tetrahydrocannabinol, have been proposed as potential anticancer agents.
KEY FINDINGS:
This review critically discusses the pharmacology of CB receptor activation as a novel therapeutic anticancer strategy in terms of ligand selectivity, tissue specificity and potency. Intriguingly, antitumour effects mediated by cannabinoids are not confined to inhibition of cancer cell proliferation; cannabinoids also reduce angiogenesis, cell migration and metastasis, inhibit carcinogenesis and attenuate inflammatory processes. In the last decade several new selective CB(1) and CB(2) receptor agents have been described, but most studies in the area of cancer research have used non-selective CB ligands. Moreover, many of these ligands exert prominent CB receptor-independent pharmacological effects, such as activation of the G-protein-coupled receptor GPR55, peroxisome proliferator-activated receptor gamma and the transient receptor potential vanilloid channels.
SUMMARY:
The role of the endocannabinoid system in tumourigenesis is still poorly understood and the molecular mechanisms of cannabinoid anticancer action need to be elucidated. The development of CB(2)-selective anticancer agents could be advantageous in light of the unwanted central effects exerted by CB(1) receptor ligands. Probably the most interesting question is whether cannabinoids could be useful in chemoprevention or in combination with established chemotherapeutic agents.”
Scientists believe marijuana compound could fight cancer
“Scientists in California believe they may have discovered a compound in marijuana that can reduce the aggressiveness of some forms of cancer.
The San Francisco Gate reports on the data that has been years in the making. While marijuana has been shown to help reduce nausea and pain in cancer patients, scientists believe that a compound in marijuana has the ability to “turn off” the activity of a gene responsible for metastasis in breast and other types of cancers.
The research team is working out of San Francisco’s California Pacific Medical Center Research Institute and have been working for years on the study. The compound they’re focused on, called cannabidiol, does not produce the psychotropic high associated with marijuana.
Last year, the team published a small study showing the positive effects of cannabidiol on mice. New data is about to be released that expands upon the previous results that the researchers hope will help propel the study even further.
“The preclinical trial data is very strong, and there’s no toxicity. There’s really a lot of research to move ahead with and to get people excited,” said Sean McAllister, who is working alongside scientist Pierre Desprez in the study.
Desprez and McAllister believe that their merging of separate areas of study was serendipitous.
Desprez had been studying the protein ID-1, which he found to play an important role in how cancer could spread. McAllister, on the other hand, was focused on studying anabolic steroids in drug abuse. He soon became focused on with the role non-psychotropic cannabidiol, or CBD, interacts with cancer.
McAllister, after hearing an internal seminar from Desprez on his studies of ID-1, came up with the question “How effective would cannabidiol be on targeting metastatic cancer cells?”
The two then teamed up, with Desprez armed with ID-1 cancer-causing protein, and McAllister with CBD, his cancer-fighting compound.
For their experimentation, the doctors exposed ID-1 to CBD in a petri dish. In a shocking result, the ID-1, the cancer-causing protein, reverted to a normal state and stopped acting “crazy.”
“We thought we did the experiment the wrong way,” McAllister said of the overwhelming results.
However, their results proved to be consisted.
“I told Sean, ‘Maybe your drug is working through my gene,’ ” Desprez said.
What the researchers have discovered thus far in their research is that CBD turns off the overexpression of ID-1, which prevents it from traveling to foreign tissues. Thus, the metastasization – cancer’s fatal ability – is blocked.
In the wake of their positive results, the doctors were forced to emphasize that the CBD will only work in the presence of high levels of ID-1 and these do not include all cancerous tumors but, rather, aggressive, metastatic cells. High levels have been found in leukemia, colorectal, pancreatic, lung, ovarian, brain and other cancers.”
Read more: http://www.irishcentral.com/news/Scientists-believe-marijuana-compound-could-fight-cancer-170689736.html#ixzz29rQbc2oS
Cannabinoids in intestinal inflammation and cancer.
Abstract
“Emerging evidence suggests that cannabinoids may exert beneficial effects in intestinal inflammation and cancer. Adaptive changes of the endocannabinoid system have been observed in intestinal biopsies from patients with inflammatory bowel disease and colon cancer. Studies on epithelial cells have shown that cannabinoids exert antiproliferative, antimetastatic and apoptotic effects as well as reducing cytokine release and promoting wound healing. In vivo, cannabinoids – via direct or indirect activation of CB(1) and/or CB(2) receptors – exert protective effects in well-established models of intestinal inflammation and colon cancer. Pharmacological elevation of endocannabinoid levels may be a promising strategy to counteract intestinal inflammation and colon cancer.”
[The endocannabinoid system as a target for the development of new drugs for cancer therapy].
“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.”
Endocannabinoid system modulation in cancer biology and therapy.
“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
Changes in the Endocannabinoid System May Give Insight into new and Effective Treatments for Cancer
“The endocannabinoid system comprises specific cannabinoid receptors such as Cb1 and Cb2, the endogenous ligands (anandamide and 2-arachidonyl glycerol among others) and the proteins responsible for their synthesis and degradation. This system has become the focus of research in recent years because of its potential therapeutic value several disease states. The following review describes our current knowledge of the changes that occur in the endocannabinoid system during carcinogenesis and then focuses on the effects of anandamide on various aspects of the carcinogenic process such as growth, migration, and angiogenesis in tumors from various origins.
Marijuana and its derivatives have been used in medicine for centuries, however, it was not until the isolation of the psychoactive component of Cannabis sativa (Δ9-tetrahydrocannabinol; Δ9-THC) and the subsequent discovery of the endogenous cannabinoid signaling system that research into the therapeutic value of this system reemerged. Ongoing research is determining that regulation of the endocannabinoid system may be effective in the treatment of pain (Calignano et al., 1998; Manzanares et al., 1999), glaucoma (Voth and Schwartz, 1997), and neurodegenerative disorders such as Parkinson’s disease (Piomelli et al., 2000) and multiple sclerosis (Baker et al., 2000). In addition, cannabinoids might be effective anti-tumoral agents because of their ability to inhibit the growth of various types of cancer cell lines in culture (De Petrocellis et al., 1998; Ruiz et al., 1999; Sanchez et al., 1998, 2001) and in laboratory animals (Galve-Roperh et al., 2000).
In conclusion, the endocannabinoid system exerts a myriad of effects on tumor cell growth, progression, angiogenesis, and migration. With a notable few exceptions, targeting the endocannabinoid system with agents that activate cannabinoid receptors or increase the endogenous levels of AEA may prove to have therapeutic benefit in the treatment of various cancers. Further studies into the downstream consequences of AEA treatment are required and may illuminate other potential therapeutic targets.”
Turned-Off Cannabinoid Receptor Turns On Colorectal Tumor Growth
“CB1 is well-established for relieving pain and nausea, elevating mood and stimulating appetite by serving as a docking station for the cannabinoid group of signaling molecules. It now may serve as a new path for cancer prevention or treatment.
“We’ve found that CB1 expression is lost in most colorectal cancers, and when that happens a cancer-promoting protein is free to inhibit cell death,” said senior author Raymond DuBois, M.D., Ph.D., provost and executive vice president of The University of Texas M. D. Anderson Cancer Center.
DuBois and collaborators from Vanderbilt-Ingram Cancer Center also show that CB1 expression can be restored with an existing drug, decitabine. They found that mice prone to developing intestinal tumors that also have functioning CB1 receptors develop fewer and smaller tumors when treated with a drug that mimics a cannabinoid receptor ligand. Ligands are molecules that function by binding to specific receptors. Agonists are synthetic molecules that mimic the action of a natural molecule.
“Potential application of cannabinoids as anti-tumor drugs is an exciting prospect, because cannabinoid agonists are being evaluated now to treat the side-effects of chemotherapy and radiation therapy,” DuBois said. “Turning CB1 back on and then treating with a cannabinoid agonist could provide a new approach to colorectal cancer treatment or prevention.”
Cannabinoids are a group of ligands that serve a variety of cell-signaling roles. Some are produced by the body internally (endocannabinoids). External cannabinoids include manmade versions and those present in plants, most famously the active ingredient in marijuana (THC).”
http://www.sciencedaily.com/releases/2008/08/080801074056.htm
Could Pot Cure Colon Cancer?
“According to researchers at the University of Texas in Houston chemicals in marijuana could be a potential cure in the treatment of colon cancer. Don’t think lighting up a joint will help though, it’s all a chemical process.
The key receptors for cannabinoids are turned off in the human body when it’s attacked by most kinds of colon cancer. Those receptors are also found in marijuana.
Using test mice scientists turned off the receptor and found that tumors quickly developed.
“When we knocked out the receptor, the number of tumors went up dramatically,” says researcher Raymond DuBois. Alternatively, when mice with normal CB1 receptors were treated with a cannabinoid compound, their tumours shrank.
The researchers are advising a two step method to treat colon cancer.
Step One is to turn the CB1 receptor back on and then activate it with drugs that mimic marijuana. The drug decitibine is already approved and does help in making the receptor. Already the second step has not been worked out Dubuis believes that using drugs that mimic marijuana will shrunk tumors.”
Cannabis-Linked Cell Receptor Might Help Prevent Colon Cancer – ABCNews
“A cannabinoid receptor lying on the surface of cells may help suppress colorectal cancer, say U.S. researchers. When the receptor is turned off, tumor growth is switched on.
Cannabinoids are compounds related to the tetrahydrocannabinol (THC) found in the cannabis plant.
It’s already known that the receptor, CB1, plays a role in relieving pain and nausea, elevating mood and stimulating appetite by serving as a docking station for the cannabinoid group of signaling molecules. This study suggests that CB1 may offer a new path for cancer prevention or treatment.
“Potential application of cannabinoids as anti-tumor drugs is an exciting prospect, because cannabinoid agonists (synthetic molecules that mimic the action of natural molecules) are being evaluated now to treat the side effects of chemotherapy and radiation therapy,” DuBois said. “Turning CB1 back on and than treating with a cannabinoid agonist could provide a new approach to colorectal cancer treatment or prevention.””
http://abcnews.go.com/Health/Healthday/story?id=5496283&page=1