Should Oncologists Recommend Cannabis?

“Cannabis is a useful botanical with a wide range of therapeutic potential. Global prohibition over the past century has impeded the ability to study the plant as medicine. However, delta-9-tetrahydrocannabinol (THC) has been developed as a stand-alone pharmaceutical initially approved for the treatment of chemotherapy-related nausea and vomiting in 1986. The indication was expanded in 1992 to include treatment of anorexia in patients with the AIDS wasting syndrome. Hence, if the dominant cannabinoid is available as a schedule III prescription medication, it would seem logical that the parent botanical would likely have similar therapeutic benefits. The system of cannabinoid receptors and endogenous cannabinoids (endocannabinoids) has likely developed to help us modulate our response to noxious stimuli. Phytocannabinoids also complex with these receptors, and the analgesic effects of cannabis are perhaps the best supported by clinical evidence. Cannabis and its constituents have also been reported to be useful in assisting with sleep, mood, and anxiety. Despite significant in vitro and animal model evidence supporting the anti-cancer activity of individual cannabinoids-particularly THC and cannabidiol (CBD)-clinical evidence is absent. A single intervention that can assist with nausea, appetite, pain, mood, and sleep is certainly a valuable addition to the palliative care armamentarium. Although many healthcare providers advise against the inhalation of a botanical as a twenty-first century drug-delivery system, evidence for serious harmful effects of cannabis inhalation is scant and a variety of other methods of ingestion are currently available from dispensaries in locales where patients have access to medicinal cannabis. Oncologists and palliative care providers should recommend this botanical remedy to their patients to gain first-hand evidence of its therapeutic potential despite the paucity of results from randomized placebo-controlled clinical trials to appreciate that it is both safe and effective and really does not require a package insert.”

https://www.ncbi.nlm.nih.gov/pubmed/31161270

https://link.springer.com/article/10.1007%2Fs11864-019-0659-9

Modulation of the Endocannabinoid System as a Potential Anticancer Strategy.

 Image result for frontiers in pharmacology“Currently, the involvement of the endocannabinoid system in cancer development and possible options for a cancer-regressive effect of cannabinoids are controversially discussed. In recent decades, a number of preclinical studies have shown that cannabinoids have an anticarcinogenic potential. Therefore, especially against the background of several legal simplifications with regard to the clinical application of cannabinoid-based drugs, an extended basic knowledge about the complex network of the individual components of the endocannabinoid system is required. The canonical endocannabinoid system consists of the endocannabinoids N-arachidonoylethanolamine (anandamide) and 2-arachidonoylglycerol as well as the Gi/o protein-coupled transmembrane cannabinoidreceptors CB1 and CB2. As a result of extensive studies on the broader effect of these factors, other fatty acid derivatives, transmembrane and intracellular receptors, enzymes and lipid transporters have been identified that contribute to the effect of endocannabinoids when defined in the broad sense as “extended endocannabinoid system.” Among these additional components, the endocannabinoid-degrading enzymes fatty acid amide hydrolase and monoacylglycerol lipase, lipid transport proteins of the fatty acid-binding protein family, additional cannabinoid-activated G protein-coupled receptors such as GPR55, members of the transient receptor family, and peroxisome proliferator-activated receptors were identified as targets for possible strategies to combat cancer progression. Other endocannabinoid-related fatty acids such as 2-arachidonoyl glyceryl ether, O-arachidonoylethanolamine, N-arachidonoyldopamine and oleic acid amide showed an effect via cannabinoid receptors, while other compounds such as endocannabinoid-like substances exert a permissive action on endocannabinoid effects and act via alternative intracellular target structures. This review gives an overview of the modulation of the extended endocannabinoid system using the example of anticancer cannabinoid effects, which have been described in detail in preclinical studies.”

https://www.ncbi.nlm.nih.gov/pubmed/31143113

“In addition to the palliative effects of cannabinoid compounds in cancer treatment, the endocannabinoid system provides several targets for systemic anticancer treatment. Accordingly, preclinical studies suggest cannabinoids inhibit cancer progression via inhibition of cancer cell proliferation, neovascularization, invasion and chemoresistance, as well as induction of apoptosis, autophagy and increase of tumor immune surveillance.”

https://www.frontiersin.org/articles/10.3389/fphar.2019.00430/full

Cannabinoid WIN 55,212-2 induces cell cycle arrest and apoptosis, and inhibits proliferation, migration, invasion, and tumor growth in prostate cancer in a cannabinoid-receptor 2 dependent manner.

The Prostate banner

“Cannabinoids have demonstrated anticarcinogenic properties in a variety of malignancies, including in prostate cancer.

In the present study, we explored the anti-cancer effects of the synthetic cannabinoid WIN 55,212-2 (WIN) in prostate cancer.

RESULTS:

WIN significantly reduced prostate cancer cell proliferation, migration, invasion, induced apoptosis, and arrested cells in Go/G1 phase in a dose-dependent manner. Mechanistic studies revealed these effects were mediated through a pathway involving cell cycle regulators p27, Cdk4, and pRb. Pre-treatment with a CB2 antagonist, AM630, followed by treatment with WIN resulted in a reversal of the anti-proliferation and cell cycle arrest previously seen with WIN alone. In vivo, administration of WIN resulted in a reduction in the tumor growth rate compared to control (P < 0.05).

CONCLUSIONS:

The following study provides evidence supporting the use of WIN as a novel therapeutic for prostate cancer.”

https://www.ncbi.nlm.nih.gov/pubmed/30242861

https://onlinelibrary.wiley.com/doi/abs/10.1002/pros.23720

Cannabidiol (CBD) Is a Novel Inhibitor for Exosome and Microvesicle (EMV) Release in Cancer.

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“Exosomes and microvesicles (EMV) are lipid bilayer-enclosed structures, released by cells and involved in intercellular communication through transfer of proteins and genetic material. EMV release is also associated with various pathologies, including cancer, where increased EMV release is amongst other associated with chemo-resistance and active transfer of pro-oncogenic factors.

Recent studies show that EMV-inhibiting agents can sensitize cancer cells to chemotherapeutic agents and reduce cancer growth in vivo.

Cannabidiol (CBD), a phytocannabinoid derived from Cannabis sativa, has anti-inflammatory and anti-oxidant properties, and displays anti-proliferative activity.

Here we report a novel role for CBD as a potent inhibitor of EMV release from three cancer cell lines: prostate cancer (PC3), hepatocellular carcinoma (HEPG2) and breast adenocarcinoma (MDA-MB-231).

CBD significantly reduced exosome release in all three cancer cell lines, and also significantly, albeit more variably, inhibited microvesicle release.

The EMV modulating effects of CBD were found to be dose dependent (1 and 5 μM) and cancer cell type specific. Moreover, we provide evidence that this may be associated with changes in mitochondrial function, including modulation of STAT3 and prohibitin expression, and that CBD can be used to sensitize cancer cells to chemotherapy.

We suggest that the known anti-cancer effects of CBD may partly be due to the regulatory effects on EMV biogenesis, and thus CBD poses as a novel and safe modulator of EMV-mediated pathological events.”

https://www.ncbi.nlm.nih.gov/pubmed/30150937

https://www.frontiersin.org/articles/10.3389/fphar.2018.00889/full

Anti-tumoural actions of cannabinoids.

British Journal of Pharmacology banner

“The endocannabinoid system has emerged as a considerable target for the treatment of diverse diseases.

In addition to the well-established palliative effects of cannabinoids in cancer therapy, phytocannabinoids, synthetic cannabinoid compounds as well as inhibitors of endocannabinoid degradation have attracted attention as possible systemic anticancer drugs.

As a matter of fact, accumulating data from preclinical studies suggest cannabinoids elicit effects on different levels of cancer progression, comprising inhibition of proliferation, neovascularisation, invasion and chemoresistance, induction of apoptosis and autophagy as well as enhancement of tumour immune surveillance.

Although the clinical use of cannabinoid receptor ligands is limited by their psychoactivity, nonpsychoactive compounds, such as cannabidiol, have gained attention due to preclinically established anticancer properties and a favourable risk-to-benefit profile.

Thus, cannabinoids may complement the currently used collection of chemotherapeutics, as a broadly diversified option for cancer treatment, while counteracting some of their severe side effects.” https://www.ncbi.nlm.nih.gov/pubmed/30019449

“During the last few decades, a large body of evidence has accumulated to suggest endocannabinoids, phytocannabinoids and synthetic cannabinoids exert an inhibitory effect on cancer growth via blockade of cell proliferation and induction of apoptosis. Some studies support the hypothesis that cannabinoids may enhance immune responses against the progressive growth and spread of tumours.”  https://bpspubs.onlinelibrary.wiley.com/doi/full/10.1111/bph.14426#bph14426-fig-0001
“Previous research has shown that cannabinoids can help lessen side effects of anti-cancer therapies. Now a new British Journal of Pharmacology review has examined their potential for the direct treatment of cancer. Studies have shown that cannabinoids may stop cancer cells from dividing and invading normal tissue, and they may block the blood supply to tumors. Some studies also indicate that cannabinoids may enhance the body’s immune response against the growth and spread of tumors.” https://www.eurasiareview.com/19072018-cannabinoids-may-have-a-vast-array-of-anti-cancer-effects/
“Cannabinoids may have a vast array of anti-cancer effects” https://www.sciencedaily.com/releases/2018/07/180718082143.htm

“Cannabinoids may have a vast array of anti-cancer effects”  https://www.eurekalert.org/pub_releases/2018-07/w-cmh071718.php

Marijuana may help fight cancer” https://nypost.com/2018/07/18/marijuana-may-help-fight-cancer/

“Cannabis stops cancer spreading and boosts immune system, say scientists. Studies show cannabinoids can stop cancer cells from dividing and spreading, and blocks blood supply to tumours” https://www.plymouthherald.co.uk/news/health/cannabis-can-cure-cancer-proof-1803485
“Cannabis stops cancer spreading and boosts immune system, say scientists. Cannabis can act as a treatment for cancer and boost the immune system, claims a new study.” https://www.devonlive.com/news/health/cannabis-can-cure-cancer-proof-1803485
“Cannabis stops cancer spreading and boosts immune system, say scientists. Cannabis can act as a treatment for cancer and boost the immune system, claims a new study.” https://www.cornwalllive.com/news/uk-world-news/cannabis-can-cure-cancer-proof-1803485
Cannabis ‘can act as a treatment for cancer’. Cannabis can enhance the immune system and act as a treatment for cancer, claims a new study. Scientists at Rostock University Medical Centre in Germany claimed the benefits following a review of more than 100 studies.” https://www.thelondoneconomic.com/news/cannabis-can-act-as-a-treatment-for-cancer/19/07/

INSIGHT ON THE IMPACT OF ENDOCANNABINOID SYSTEM IN CANCER: A REVIEW.

British Journal of Pharmacology banner

“In the last decades, the endocannabinoid system has attracted a great interest in medicine and cancer disease is probably one of its most promising therapeutic areas.

On the one hand, endocannabinoid system expression has been found altered in numerous types of tumours compared to healthy tissue, and this aberrant expression has been related to cancer prognosis and disease outcome, suggesting a role of this system in tumour growth and progression that depends on cancer type.

On the other hand, it has been reported that cannabinoids exert an anticancer activity by inhibiting the proliferation, migration and/or invasion of cancer cells; and also tumour angiogenesis.

The endocannabinoid system may be considered as a new therapeutic target, although further studies to fully establish the effect of cannabinoids on tumour progression remain necessary.”

https://www.ncbi.nlm.nih.gov/pubmed/29663308

A Review of the Therapeutic Antitumor Potential of Cannabinoids.

:Image result for J Altern Complement Med.

“The aim of this review is to discuss cannabinoids from a preclinical and clinical oncological perspective and provide the audience with a concise, retrospective overview of the most significant findings concerning the potential use of cannabinoids in cancer treatment.

RESULTS:

Cannabis sativa is a plant rich in more than 100 types of cannabinoids. Besides exogenous plant cannabinoids, mammalian endocannabinoids and synthetic cannabinoid analogues have been identified. Cannabinoid receptors type 1 (CB1) and type 2 (CB2) have been isolated and characterized from mammalian cells. Through cannabinoid receptor and non-receptor signaling pathways, cannabinoids show specific cytotoxicity against tumor cells, while protecting healthy tissue from apoptosis. The dual antiproliferative and proapoptotic effects of cannabinoids and associated signaling pathways have been investigated on a large panel of cancer cell lines. Cannabinoids also display potent anticancer activity against tumor xenografts, including tumors that express high resistance to standard chemotherapeutics. Few studies have investigated the possible synergistic effects of cannabinoids with standard oncology therapies, and are based on the preclinically confirmed concept of “cannabinoid sensitizers.” Also, clinical trials aimed to confirm the antineoplastic activity of cannabinoids have only been evaluated on a small number of subjects, with no consensus conclusions regarding their effectiveness.

CONCLUSIONS:

A large number of cannabinoid compounds have been discovered, developed, and used to study the effects of cannabinoids on cancers in model systems. However, few clinical trials have been conducted on the use of cannabinoids in the treatment of cancers in humans. Further studies require extensive monitoring of the effects of cannabinoids alone or in combination with standard anticancer strategies. With such knowledge, cannabinoids could become a therapy of choice in contemporary oncology.”

Systematic review of the potential role of cannabinoids as antiproliferative agents for urological cancers.

“The palliative effects of cannabis sativa (marijuana), which include appetite stimulation, attenuation of nausea and emesis, and pain relief, are well known.

The active components of cannabis sativa (cannabinoids) and their derivatives have received growing interest due to their diverse pharmacological activities, such as cell growth inhibition and tumour regression.

The aim of this review is to look at the current evidence on the antiproliferative effects of cannabinoids in urological malignancies, including renal, prostate, bladder, and testicular cancers.

The search yielded a total of 93 studies from Medline and PubMed, of which 23 studies were included in the final analysis. To date, there are various in vitro studies elucidating the potential mechanism of action of cannabinoids for urological cancers, along with population-based studies specifically for testicular malignancies. To date, no clinical trials have been conducted for urological cancer patients.

These results demonstrate that the role of endocannabinoids for urological malignancies is an area of active research. Further research is required not only to evaluate the crosstalk between cancer signaling pathways and cannabinoids, but also large randomized clinical studies with urological patients need to be conducted before cannabinoids can be introduced as potential therapeutic options for urological neoplasms.”

https://www.ncbi.nlm.nih.gov/pubmed/28515817

http://www.cuaj.ca/index.php/journal/article/view/4371

Cannabinoids as Modulators of Cell Death: Clinical Applications and Future Directions.

 Image result for Rev Physiol Biochem Pharmacol.

“Endocannabinoids are bioactive lipids that modulate various physiological processes through G-protein-coupled receptors (CB1 and CB2) and other putative targets. By sharing the activation of the same receptors, some phytocannabinoids and a multitude of synthetic cannabinoids mimic the effects of endocannabinoids.

In recent years, a growing interest has been dedicated to the study of cannabinoids properties for their analgesic, antioxidant, anti-inflammatory and neuroprotective effects. In addition to these well-recognized effects, various studies suggest that cannabinoids may affect cell survival, cell proliferation or cell death. These observations indicate that cannabinoids may play an important role in the regulation of cellular homeostasis and, thus, may contribute to tissue remodelling and cancer treatment.

For a long time, the study of cannabinoid receptor signalling has been focused on the classical adenylyl cyclase/cyclic AMP/protein kinase A (PKA) pathway. However, this pathway does not totally explain the wide array of biological responses to cannabinoids. In addition, the diversity of receptors and signalling pathways that endocannabinoids modulate offers an interesting opportunity for the development of specific molecules to disturb selectively the endogenous system.

Moreover, emerging evidences suggest that cannabinoids ability to limit cell proliferation and to induce tumour-selective cell death may offer a novel strategy in cancer treatment.

This review describes the main properties of cannabinoids in cell death and attempts to clarify the different pathways triggered by these compounds that may help to understand the complexity of respective molecular mechanisms and explore the potential clinical benefit of cannabinoids use in cancer therapies.”

https://www.ncbi.nlm.nih.gov/pubmed/28425013

A Science Based Evaluation of Cannabis and Cancer

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“The irritant properties of all smoke will naturally tend to promote a pro-inflammatory immune response with the corresponding production of potentially carcinogenic free radicals. However, cannabis promotes immune deviation to an anti-inflammatory Th2 response via immune-system specific CB2 receptors. Thus, the natural pharmacological properties of marijuana’s cannabinoids, that are not present in tobacco smoke, would minimize potential irritant initiated carcinogenesis. In contrast, the pharmacological activities of tobacco smoke would tend to amplify its carcinogenic potential by inhibiting the death of genetically damaged cells. Together these observations support the epidemiological study of the Kaiser Foundation that did not find cannabis smoking to be associated with cancer incidence. Additionally, the demonstrated cancer killing activities of cannabinoids has been ignored. Cannabinoids have been shown to kill some leukemia and lymphoma, breast and prostate, pheochromocytoma, glioma and skin cancer cells in cell culture and in animals.” http://www.bmj.com/rapid-response/2011/10/29/science-based-evaluation-cannabis-and-cancer