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

β-Caryophyllene, a natural bicyclic sesquiterpene attenuates doxorubicin-induced cardiotoxicity via activation of myocardial cannabinoid type-2 (CB2) receptors in rats.

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“The cannabinoid type 2 receptor (CB2) has recently emerged as an important therapeutic target for cancer as well as cardiovascular diseases. The CB2 receptor downregulation has been reported in solid tumors and cardiovascular diseases, therefore the CB2receptor activation has been considered as a viable strategy for chemotherapy as well as cardioprotection.

In chemotherapy, doxorubicin (DOX) is an important drug that continues to be the mainstay of chemotherapy in solid tumors, leukemia, and lymphoma. However, the use of DOX is often limited due to its lethal cardiotoxicity. Considering the role of CB2 receptors in cardiovascular diseases and cancer, the activation of CB2 receptors may protect against DOX-induced chronic cardiotoxicity in rats.

In the present study, we investigated the cardioprotective effect of a selective CB2 receptor agonist; β-Caryophyllene (BCP), a natural bicyclic sesquiterpene, against DOX-induced chronic cardiotoxicity in rats. AM630, a CB2 receptor antagonist was administered as a pharmacological challenge prior to BCP treatment to demonstrate CB2 receptor mediated cardioprotective mechanism of BCP. DOX (2.5 mg/kg) was injected intraperitoneally once a week for five weeks to induce chronic cardiotoxicity in rats.

BCP was also injected into rats six days a week for a total duration of five weeks. DOX induced a significant decline in cardiac function and oxidative stress evidenced by the depletion of antioxidant enzymes, glutathione, and increased lipid peroxidation. DOX also triggered activation of nuclear factor kappa B (NF-κB) and increased the levels of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β) and expression of the inflammatory mediators (iNOS and COX-2) in the heart.

Furthermore, DOX also upregulated the expression of pro-apoptotic markers such as Bax, p53, cleaved PARP, active caspase-3 and downregulated anti-apoptotic marker Bcl-2 in the myocardium. BCP treatment exerted significant cardioprotective effect by salvaging the heart tissues, improving cardiac function, mitigating oxidative stress, inflammation, and apoptosis. The histological and ultrastructural studies also appear in line with our findings of biochemical and molecular parameters.

The CB2 receptor-mediated cardioprotective mechanism was further confirmed by the abrogation of the beneficial effects of BCP with prior administration of the CB2 receptor antagonist; AM630.

Our study revealed the novel mechanism of BCP in cardioprotection against DOX-induced chronic cardiotoxicity by the activation of CB2 receptors.”

https://www.ncbi.nlm.nih.gov/pubmed/30836069

https://www.sciencedirect.com/science/article/pii/S0009279718316284?via%3Dihub

“β-caryophyllene (BCP) is a common constitute of the essential oils of numerous spice, food plants and major component in Cannabis.”   http://www.ncbi.nlm.nih.gov/pubmed/23138934

“Beta-caryophyllene is a dietary cannabinoid.”   https://www.ncbi.nlm.nih.gov/pubmed/18574142

Anti-tumoural actions of cannabinoids.

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“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/

Anti-Proliferative Properties and Proapoptotic Function of New CB2 Selective Cannabinoid Receptor Agonist in Jurkat Leukemia Cells.

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“Several studies demonstrated that cannabinoids reduce tumor growth, inhibit angiogenesis, and decrease cancer cell migration. As these molecules are well tolerated, it would be interesting to investigate the potential benefit of newly synthesized compounds, binding cannabinoid receptors (CBRs).

In this study, we describe the synthesis and biological effect of 2-oxo-1,8-naphthyridine-3-carboxamide derivative LV50, a new compound with high CB2 receptor (CB2R) affinity. We demonstrated that it decreases viability of Jurkat leukemia cells, evaluated by Trypan Blue and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), but mainly induces a proapoptotic effect. We observed an increase of a hypodiploid peak by propidium iodide staining and changes in nuclear morphology by Hoechst 33258. These data were confirmed by a significant increase of Annexin V staining, cleavage of the nuclear enzyme poly(ADP-ribose)-polymerase (PARP), and caspases activation. In addition, in order to exclude that LV50 non-specifically triggers death of all normal leukocytes, we tested the new compound on normal peripheral blood lymphocytes, excluding the idea of general cytotoxicity. To characterize the involvement of CB2R in the anti-proliferative and proapoptotic effect of LV50, cells were pretreated with a specific CB2R antagonist and the obtained data showed reverse results.

Thus, we suggest a link between inhibition of cell survival and proapoptotic activity of the new compound that elicits this effect as selective CB2R agonist.”

https://www.ncbi.nlm.nih.gov/pubmed/29973514

http://www.mdpi.com/1422-0067/19/7/1958

Effects of CB2 and TRPV1 receptors’ stimulation in pediatric acute T-lymphoblastic leukemia

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“T-Acute Lymphoblastic Leukemia (T-ALL) is less frequent than B-ALL, but it has poorer outcome. For this reason new therapeutic approaches are needed to treat this malignancy.

The Endocannabinoid/Endovanilloid (EC/EV) system has been proposed as possible target to treat several malignancies, including lymphoblastic diseases. The EC/EV system is composed of two G-Protein Coupled Receptors (CB1 and CB2), the Transient Potential Vanilloid 1 (TRPV1) channel, their endogenous and exogenous ligands and enzymes. CB1 is expressed mainly in central nervous system while CB2 predominantly on immune and peripheral cells, therefore we chose to selectively stimulate CB2 and TRPV1.

We treated T-ALL lymphoblasts derived from 4 patients and Jurkat cells with a selective agonist at CB2 receptor: JWH-133 [100 nM] and an agonist at TRPV1 calcium channel: RTX [5 uM] at 6, 12 and 24 hours. We analyzed the effect on apoptosis and Cell Cycle Progression by a cytofluorimetric assays and evaluated the expression level of several target genes (Caspase 3, Bax, Bcl-2, AKT, ERK, PTEN, Notch-1, CDK2, p53) involved in cell survival and apoptosis, by Real-Time PCR and Western Blotting.

We observed a pro-apoptotic, anti-proliferative effect of these compounds in both primary lymphoblasts obtained from patients with T-ALL and in Jurkat cell line. Our results show that both CB2 stimulation and TRPV1 activation, can increase the apoptosis in vitro, interfere with cell cycle progression and reduce cell proliferation, indicating that a new therapeutic approach to T-cell ALL might be possible by modulating CB2 and TRPV1 receptors.”

http://www.oncotarget.com/index.php?journal=oncotarget&page=article&op=view&path%5B%5D=25052

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

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“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

Study shows non-hallucinogenic cannabinoids are effective anti-cancer drugs

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“New research has shown that the non-hallucinogenic components of cannabis could act as effective anti-cancer agents. The anti-cancer properties of tetrahydrocannabinol (THC), the primary hallucinogenic component of cannabis, has been recognised for many years, but research into similar cannabis-derived compounds, known as cannabinoids, has been limited.

The study was carried out by a team at St George’s, University of London. It has been published in the journal Anticancer Research. The team, led by Dr Wai Liu and colleagues carried out laboratory investigations using a number of cannabinoids, either alone or in combination with each other, to measure their anti-cancer actions in relation to leukaemia.

Of six cannabinoids studied, each demonstrated anti-cancer properties as effective as those seen in THC. Importantly, they had an increased effect on cancer cells when combined with each other.

Dr Liu said: “This study is a critical step in unpicking the mysteries of cannabis as a source of medicine. The cannabinoids examined have minimal, if any, hallucinogenic side effects, and their properties as anti-cancer agents are promising.

“These agents are able to interfere with the development of cancerous cells, stopping them in their tracks and preventing them from growing. In some cases, by using specific dosage patterns, they can destroy cancer cells on their own.

“Used in combination with existing treatment, we could discover some highly effective strategies for tackling cancer. Significantly, these compounds are inexpensive to produce and making better use of their unique properties could result in much more cost effective anti-cancer drugs in future.”

The study examined two forms of cannabidiol (CBD), two forms of cannabigerol (CBG) and two forms of cannabigevarin (CBGV). These represent the most common cannabinoids found in the cannabis plant apart from THC.” https://www.sgul.ac.uk/alumni/magazine/study-shows-non-hallucinogenic-cannabinoids-are-effective-anti-cancer-drugs

“Enhancing the Activity of Cannabidiol and Other Cannabinoids In Vitro Through Modifications to Drug Combinations and Treatment Schedules”  http://ar.iiarjournals.org/content/33/10/4373.abstract

“Non-hallucinogenic cannabinoids are effective anti-cancer drugs” https://www.sciencedaily.com/releases/2013/10/131014094105.htm

“Cannabinoids used in sequence with chemotherapy are a more effective treatment for cancer. New research has confirmed that cannabinoids – the active chemicals in cannabis – are effective in killing leukaemia cells, particularly when used in combination with chemotherapy treatments.” https://www.sgul.ac.uk/news/news-archive/cannabinoids-used-in-sequence-with-chemotherapy-are-a-more-effective-treatment-for-cancer
 
“Anticancer effects of phytocannabinoids used with chemotherapy in leukaemia cells can be improved by altering the sequence of their administration.” https://www.ncbi.nlm.nih.gov/pubmed/28560402

Anticancer effects of phytocannabinoids used with chemotherapy in leukaemia cells can be improved by altering the sequence of their administration.

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“Phytocannabinoids possess anticancer activity when used alone, and a number have also been shown to combine favourably with each other in vitro in leukaemia cells to generate improved activity.

We have investigated the effect of pairing cannabinoids and assessed their anticancer activity in cell line models. Those most effective were then used with the common anti-leukaemia drugs cytarabine and vincristine, and the effects of this combination therapy on cell death studied in vitro.

Results show a number of cannabinoids could be paired together to generate an effect superior to that achieved if the components were used individually.

For example, in HL60 cells, the IC50 values at 48 h for cannabidiol (CBD) and tetrahydrocannabinol (THC) when used alone were 8 and 13 µM, respectively; however, if used together, it was 4 µM. Median-effect analysis confirmed the benefit of using cannabinoids in pairs, with calculated combination indices being <1 in a number of cases.

The most efficacious cannabinoid-pairs subsequently synergised further when combined with the chemotherapy agents, and were also able to sensitise leukaemia cells to their cytotoxic effects.

The sequence of administration of these drugs was important though; using cannabinoids after chemotherapy resulted in greater induction of apoptosis, whilst this was the opposite when the schedule of administration was reversed.

Our results suggest that when certain cannabinoids are paired together, the resulting product can be combined synergistically with common anti-leukaemia drugs allowing the dose of the cytotoxic agents to be dramatically reduced yet still remain efficacious. Nevertheless, the sequence of drug administration is crucial to the success of these triple combinations and should be considered when planning such treatments.”

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

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“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