How cannabis suppresses immune functions: Cannabis compounds found to trigger unique immune cells which promote cancer growth
November 26, 2010
Science Daily/Wiley-Blackwell
An international team of immunologists studying the effects of cannabis have discovered how smoking marijuana can trigger a suppression of the body's immune functions. The research, published in the European Journal of Immunology, reveals why cannabis users are more susceptible to certain types of cancers and infections.
The team, led by Dr Prakash Nagarkatti from the University of South Carolina, focused their research on cannabinoids, a group of compounds found inside the cannabis plant, including THC (delta-9 tetahydrocannabinol) which is already used for medical purposes such as pain relief.
"Cannabis is one of the most widely used drugs of abuse worldwide and it is already believed to suppress immune functions making the user more susceptible to infections and some types of cancer," said Dr Nagarkatti. "We believe the key to this suppression is a unique type of immune cell, which has only recently been identified by immunologists, called myeloid-derived suppressor cells, MDSCs."
While most immune cells fight against infections and cancers to protect the host, MDSCs actively suppress the immune system. The presence of these cells is known to increase in cancer patients and it is believed that MDSCs may suppress the immune system against cancer therapy, actually promoting cancer growth.
Dr Nagarkatti's team demonstrated that cannabinoids can trigger a massive number of MDSCs through activation of cannabinoid receptors. This research reveals, for the first time, that marijuana cannabinoids may suppress the immune system by activating these unique cells.
"These results raise interesting questions on whether increased susceptibility to certain types of cancers or infections caused from smoking marijuana results from induction of MDSCs," said Nagarkatti. "MDSCs seem to be unique and important cells that may be triggered by inappropriate production of certain growth factors by cancer cells or other chemical agents such as cannabinoids, which lead to a suppression of the immune system's response."
In a related study, also published in the European journal of Immunology, Dr Christian Vosshenrich from the Institut Pasteur in Paris, reveals that when cancer cells grow they produce a molecule called interleukin-1 β (IL-1β), which also triggers MDSCs. This study identifies how MDSCs produced during cancer growth also weaken the ability of immune cells to kill cancer cells.
"Marijuana cannabinoids present us with a double edged sword," concluded Dr Nagarkatti. "On one hand, due to their immunosuppressive nature, they can cause increased susceptibility to cancer and infections. However, further research of these compounds could provide opportunities to treat a large number of clinical disorders where suppressing the immune response is actually beneficial."
https://www.sciencedaily.com/releases/2010/11/101124214728.htm
Patients with or without cancer use different forms of marijuana
March 26, 2019
NYU Langone Health / NYU School of Medicine
People with and without cancer are more likely, over time, to use a more potent form of medical marijuana with increasingly higher amounts of tetrahydrocannabinol (THC), a new study shows.
In a report publishing in the Journal of Palliative Medicine on March 26, researchers say that cancer patients were more likely to favor forms of medical marijuana with higher amounts of THC, which relieves cancer symptoms and the side effects of cancer treatment, including chronic pain, weight loss, and nausea.
By contrast, marijuana formulations higher in cannabidiol (CBD), which has been shown to reduce seizures and inflammation in other studies, were more popular among non-cancer patients, including those with epilepsy and multiple sclerosis, say the study authors.
Cancer patients were also more likely to prefer taking oil droplets containing medical marijuana under the tongue than "vaping."
"Although there is growing patient interest in medical cannabis, there is a scarcity of solid evidence about the benefits, risks, and patterns of use of marijuana products in various disease settings," says study lead investigator Arum Kim, MD, an assistant professor of medicine and rehabilitation medicine at NYU School of Medicine and director of the supportive oncology program at its Perlmutter Cancer Center. "Such information is important for delivering the best care."
Since 1996, 31 states, including New York in 2014, have legalized medical marijuana.
For the study, researchers analyzed data from 11,590 men and women in New York, of whom 1,990 (17.2 percent of the total patient cohort) were cancer patients who purchased and used cannabis products from Columbia Care LLC., a dispensary licensed in New York State, between January 2016 and December 2017.
The researchers caution that their data did not include the type of cancer the purchasers had, how much of what they bought was used, or whether marijuana was used for symptoms unrelated to the cancer. Nevertheless, the patterns of use among cancer patients were distinctly different from those of non-cancer patients.
Specifically, the study found that cancer and non-cancer patients used different dosages of cannabis formulations with dramatically different THC:CBD ratios. The two most common formulations contained THC and CBD, but one had twenty times more THC than CBD, whereas the other had the opposite ratio.
Over the two years of the study, the research team found that all types of patients increased their THC dose by approximately 0.20 milligrams per week.
"Our study provides valuable new information about how cancer patients are using marijuana," says study senior investigator Benjamin Han, MD, MPH, an assistant professor of medicine and population health at NYU School of Medicine. "In the absence of strong clinical research data for medical marijuana, identifying patterns of use offers some sense of how to guide patients who come in with questions for using medical marijuana, and what may or may not help them."
Researchers say they next plan to get more detailed information about how medical marijuana affects patient response to therapy and functional status at different stages of their disease, as well as the risks and side effects of treatment. Furthermore, the profiles of other cannabinoids besides THC and CBD in medical marijuana products warrant further research, according to the study authors.
Along with Kim and Han, another co-author from NYU School of Medicine and Perlmutter Cancer Center, which funded the study, was Zujun Li, MD. Other study authors include Christopher Kaufmann, PhD, MHS, at University of California San Diego; and Roxanne Ko, BA, BS, at the University of Hawaii.
https://www.sciencedaily.com/releases/2019/03/190326081343.htm
Cannabinoids used in sequence with chemotherapy are a more effective treatment for cancer
June 5, 2017
Science Daily/University of St George's London
New research has confirmed that cannabinoids -- the active chemicals in cannabis -- are effective in killing leukemia cells, particularly when used in combination with chemotherapy treatments.
Researchers also found that sequential use of an initial dose of chemotherapy first and then cannabinoids significantly improved overall results against the blood cancer cells. They found that combining existing chemotherapy treatments with cannabinoids had better results than chemotherapy alone, meaning that a similar level of effect could be achieved through using a lower dose of the chemotherapy.
If this were translated to humans, this lower dose of chemotherapy would mean that the side-effects of chemotherapy could be lessened.
In a study led by Dr Wai Liu at St George's, University of London, said: "We have shown for the first time that the order in which cannabinoids and chemotherapy are used is crucial in determining the overall effectiveness of this treatment.
"These extracts are highly concentrated and purified, so smoking marijuana will not have a similar effect. But cannabinoids are a very exciting prospect in oncology, and studies such as ours serve to establish the best ways that they should be used to maximise a therapeutic effect."
Cannabinoids are the active chemicals in cannabis, known more specifically as phytocannabinoids. When extracted from the plant and purified, they have been shown to possess anticancer properties, especially in certain cancers of the brain.
Researchers looked at cancer cells in the laboratory, trying different combinations of cannabinoids against leukemia cells. They tested whether existing chemotherapy treatments worked effectively alongside the cannabinoids, and whether using the drugs in a different order had an effect.
A number of clinical studies are underway that are assessing the full potential of cannabinoids in patients with cancer. Researchers say more trials need to be carried out to establish the voracity of the claims.
https://www.sciencedaily.com/releases/2017/06/170605085559.htm
Cannabis extract can have dramatic effect on brain cancer
November 14, 2014
Science Daily/University of St George's London
Experts have shown that when certain parts of cannabis are used to treat cancer tumours alongside radio therapy treatment the growths can virtually disappear.
The new research by specialists at St George's, University of London, studied the treatment of brain cancer tumours in the laboratory and discovered that the most effective treatment was to combine active chemical components of the cannabis plant which are called cannabinoids.
Two of these called tetrahydrocannabinol (THC) and cannabidiol (CBD) were tested as part of the research into brain cancer which is particularly difficult to treat and claims the lives of about 5,200 each year. It also has a particularly poor prognosis as the rate of survival after five years of patients' diagnosis is around 10%.
Cannabinoids are the active chemicals in cannabis and are also known more specifically as phytocannabinoids. There are 85 known cannabinoids in the cannabis plant.
The new research is the first to show a drastic effect when combining THC and CBD with irradiation. Tumours growing in the brains of mice were drastically slowed down when THC/CBD was used with irradiation.
Dr Wai Liu, Senior Research Fellow and lead researcher on the project, said: "The results are extremely exciting. The tumours were treated in a variety of ways, either with no treatment, the cannabinoids alone, and irradiation alone or with both the cannabinoids and irradiation at the same time.
"Those treated with both irradiation and the cannabinoids saw the most beneficial results and a drastic reduction in size. In some cases, the tumours effectively disappeared in the animals. This augurs well for further research in humans in the future. At the moment this is a mostly fatal disease.
"The benefits of the cannabis plant elements were known before but the drastic reduction of brain cancers if used with irradiation is something new and may well prove promising for patients who are in gravely serious situations with such cancers in the future."
The research team are discussing the possibility of combining cannabinoids with irradiation in a human clinical trial.
The research has been published in the Molecular Cancer Therapeutics journal.
Cannabinoids are the active chemicals in cannabis and are also known more specifically as phytocannabinoids. There are 85 known cannabinoids in the cannabis plant. The primary psychoactive component of cannabis is called tetrahydrocannabinol (THC).
https://www.sciencedaily.com/releases/2014/11/141114085629.htm