Receptor-dependent and Receptor-independent Endocannabinoid Signaling: A Therapeutic Target for Regulation of Cancer Growth.

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“The endocannabinoid system comprises the G-protein coupled CB1 cannabinoid receptor (CB1R) and CB2 cannabinoid receptor (CB2R), their endogenous ligands (endocannabinoids), and the enzymes responsible for their synthesis and catabolism. Recent works have revealed several important interactions between the endocannabinoid system and cancer. Moreover, it is now well established that synthetic small molecule cannabinoid receptor agonist acting on either CB1R or CB2R or both exert anti-cancer effects on a variety of tumor cells. Recent results from many laboratories reported that the expression of CB1R and CB2R in prostate cancer, breast cancer, and many other cancer cells are higher than corresponding non-malignant tissues. The mechanisms by which cannabinoids acting on CB1R or CB2R exert their effects on cancer cells are quite diverse and complex. Further, several studies demonstrated that some of the anti-proliferative and apoptotic effects of cannabinoids are mediated by receptor-independent mechanisms. In this minreview we provide an overview of the major findings on the effects of endogenous and/or synthetic cannabinoids on breast and prostate cancer. We also provide insight into receptor independent mechanisms of the anti-cancer effects of cannabinoids under in vitro and in vivo conditions.” http://www.ncbi.nlm.nih.gov/pubmed/23069587

http://www.sciencedirect.com/science/article/pii/S0024320512005930

Targeting the endocannabinoid system for the treatment of cancer– a practical view.

“In recent years, considerable interest has been generated by findings that cannabinoids not only have useful palliative effects, but also can affect the viability and invasivity of a variety of different cancer cells. In the present review, the potential of targeting the cannabinoid system for the treatment of cancer is considered from a practical, rather than a mechanistic viewpoint, addressing questions such as whether human tumour cells express CB receptors; whether the potencies of action of cannabinoids in vitro match the potencies expected on the base of receptor theory; what is known about the in vivo effects of cannabinoids and cancer, and how relevant the experiments undertaken are to the clinical situation; and finally, what approaches can be taken to minimise unwanted effects of cannabinoid treatment. It is concluded that cannabinoids (or agents modulating the endogenous cannabinoid system) are an attractive target for drug development in the cancer area, but that more in vivo studies, particularly those investigating the potential of cannabinoids as an addition to current treatment strategies, are needed.”  http://www.ncbi.nlm.nih.gov/pubmed/20370711

http://www.eurekaselect.com/85470/article

Cannabinoids, Endocannabinoids and Cancer

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“The endocannabinoid system consists of an array of endogenously produced bioactive lipids that activate cannabinoid receptors. Although the primary focus of endocannabinoid biology has been on neurological and psychiatric effects, recent work has revealed several important interactions between the endocannabinoid system and cancer. Several different types of cancer have abnormal regulation of the endocannabinoid system that contributes to cancer progression and correlates to clinical outcomes.

Modulation of the endocannabinoid system by pharmacological agents in various cancer types reveals that it can mediate antiproliferative and apoptotic effects by both cannabinoid receptor-dependent and -independent pathways. Selective agonists and antagonists of the cannabinoid receptors, inhibitors of endocannabinoid hydrolysis, and cannabinoid analogs have been utilized to probe the pathways involved in the effects of the endocannabinoid system on cancer cell apoptosis, proliferation, migration, adhesion, and invasion. The antiproliferative and apoptotic effects produced by some of these pharmacological probes reveal that the endocannabinoid system is a promising new target for the development of novel chemotherapeutics to treat cancer.”

Although there is a strong set of data in vitro, in cellular model systems, and in mouse model systems, there is a dearth of clinical data on the effects of cannabinoids in the treatment of cancer in humans. This fact is quite surprising considering the large library of compounds that have been developed and used to study the effects of cannabinoids on cancer in model systems.

Despite the lack of preclinical and clinical data, there is a strong agreement that pharmacological targeting of the endocannabinoid system is emerging as one of the most promising new methods for reducing the progression of cancer. In particular, combination therapy utilizing both traditional chemotherapeutics and molecules targeting the endocannabinoid system may be an excellent next generation treatment for cancer.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3366283/

The endocannabinoid system in cancer-potential therapeutic target?

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“Endogenous arachidonic acid metabolites with properties similar to compounds of Cannabis sativa Linnaeus, the so-called endocannabinoids, have effects on various types of cancer. Although endocannabinoids and synthetic cannabinoids may have pro-proliferative effects, predominantly inhibitory effects on tumor growth, angiogenesis, migration and metastasis have been described. Remarkably, these effects may be selective for the cancer cells, while normal cells and tissues are spared. Such apparent tumor cell selectivity makes the endocannabinoid system an attractive potential target for cancer therapy. In this review we discuss various means by which the endocannabinoid system may be targeted in cancer and the current knowledge considering the regulation of the endocannabinoid system in malignancy.”  http://www.ncbi.nlm.nih.gov/pubmed/18249558

http://www.sciencedirect.com/science/article/pii/S1044579X07001058

Endocannabinoids as emerging suppressors of angiogenesis and tumor invasion (review).

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“The medicinal properties of extracts from the hemp plant Cannabis sativa have been known for centuries but only in the 90s membrane receptors for the Cannabis major principle were discovered in mammalian cells. Later on the endogenous ligands for the cannabinoid receptors were identified and the term ‘endocannabinoid system’ was coined to indicate the complex signaling system of cannabinoid receptors, endogenous ligands and the enzymes responsible for their biosynthesis and inactivation.

The ‘endocannabinoid system’ is involved in a broad range of functions and in a growing number of pathological conditions.

There is increasing evidence that endocannabinoids are able to inhibit cancer cell growth in culture as well as in animal models.

Most work has focused on the role of endocannabinoids in regulating tumor cell growth and apoptosis and ongoing research is addressed to further dissect the precise mechanisms of cannabinoid antitumor action. However, endocannabinoids are now emerging as suppressors of angiogenesis and tumor spreading since they have been reported to inhibit angiogenesis, cell migration and metastasis in different types of cancer, pointing to a potential role of the endocannabinoid system as a target for a therapeutic approach of such malignant diseases.

The potential use of cannabinoids to retard tumor growth and spreading is even more appealing considering that they show a good safety profile, regarding toxicity, and are already used in cancer patients as palliatives to stimulate appetite and to prevent devastating effects such as nausea, vomiting and pain.”  http://www.ncbi.nlm.nih.gov/pubmed/17342320

https://www.spandidos-publications.com/or/17/4/813

The endocannabinoid system in the cancer therapy: an overview.

“The endocannabinoid system comprises the cannabinoid receptors type 1 (CB1) and type 2 (CB2), their endogenous ligands (endocannabinoids), and the proteins responsible for their biosynthesis and degradation. This ubiquitous signalling system, that has attracted a great deal of scientist interest in the past 15 years, regulates several physiological and pathological functions. In mammals, among other functions, the endocannabinoid is involved in nervous, cardiovascular, metabolic, reproductive and immune functions. Finally, yet importantly, endocannabinoids are known to exert important antiproliferative actions in a great number of tumor cells including breast, brain, skin, thyroid, prostate and colorectal. The following review describes our current knowledge on the effects of two of the most studied endocannabinoids (AEA and 2-AG) on various types of tumor and summarizes the possible mechanism of observed antitumor effects.”  http://www.ncbi.nlm.nih.gov/pubmed/21428888

http://www.eurekaselect.com/73874/article

The endocannabinoid system and cancer: therapeutic implication

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“The endocannabinoid system is implicated in a variety of physiological and pathological conditions (inflammation, immunomodulation, analgesia, cancer and others).

The main active ingredient of cannabis, Δ(9) -tetrahydrocannabinol (Δ(9) -THC), produces its effects through activation of CB(1) and CB(2) receptors. CB(1) receptors are expressed at high levels in the central nervous system (CNS), whereas CB(2) receptors are concentrated predominantly, although not exclusively, in cells of the immune system.

Endocannabinoids are endogenous lipid-signalling molecules that are generated in the cell membrane from phospholipid precursors. The two best characterized endocannabinoids identified to date are anandamide (AEA) and 2-arachidonoylglycerol (2-AG). Here we review the relationship between the endocannabinoid system and anti-tumour actions (inhibition of cell proliferation and migration, induction of apoptosis, reduction of tumour growth) of the cannabinoids in different types of cancer.

This review will focus on examining how activation of the endocannabinoid system impacts breast, prostate and bone cancers in both in vitro and in vivo systems. The therapeutic potential of cannabinoids for cancer, as identified in clinical trials, is also discussed.

Identification of safe and effective treatments to manage and improve cancer therapy is critical to improve quality of life and reduce unnecessary suffering in cancer patients. In this regard, cannabis-like compounds offer therapeutic potential for the treatment of breast, prostate and bone cancer in patients.

Further basic research on anti-cancer properties of cannabinoids as well as clinical trials of cannabinoid therapeutic efficacy in breast, prostate and bone cancer is therefore warranted.” http://www.ncbi.nlm.nih.gov/pubmed/21410463

“The available literature suggests that the endocannabinoid system may be targeted to suppress the evolution and progression of breast, prostate and bone cancer as well as the accompanying pain syndromes. Many in vitro and in vivo studies have shown that cannabinoids are efficacious in reducing cancer progression (i.e. inhibition of tumour growth and metastases as well as induction of apoptosis and other anti-cancer properties) in breast, prostate and bone cancer. Although this review focuses on these three types of cancer, activation of the endocannabinoid signalling system produces anti-cancer effects in other types of cancer.” http://onlinelibrary.wiley.com/doi/10.1111/j.1476-5381.2011.01327.x/full

THC From Cannabis Destroys Cancer Cells

“The study results strongly suggest that if taken regularly, cannabis oil may be able to induce remission in leukemia patients without the horrendous side effects typically associated with standard radio-chemical treatment options. Although this is only one such study, other similar studies have shown equally impressive results.

 Many of the active ingredients found in cannabis-derived drugs show exceptional promise in treating some of the greatest hurdles facing modern medical science. In addition to their aforementioned capacity for safely treating certain forms of deadly cancer, they also show great promise in alleviating autoimmune conditions such as rheumatoid arthritis, multiple sclerosis, and even inflammatory bowel disease. A growing number of experts also note their possible viability treating a range of neurological disorders including Alzheimer’s and Lou Gehrig’s disease.”

http://www.globalhealingcenter.com/natural-health/thc-from-cannabis-destroys-cancer-cells/

Cannabinoid receptor activation correlates with the pro-apoptotic action of the β2-adrenergic agonist, (R,R’)-4-methoxy-1-naphthylfenoterol, in HepG2 hepatocarcinoma cells

“In the last several years, development of new CBR ligands has become an intense area in cancer research because of the role of the endocannabinoid system in the regulation of cell proliferation and apoptosis…

The therapeutic potential for synthetic small bivalent ligands holds great promise as new lead compounds in a wide range of disparate diseases.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3464034/

Anti-tumoral action of cannabinoids on hepatocellular carcinoma: role of AMPK-dependent activation of autophagy

“Hepatocellular carcinoma (HCC) is the third cause of cancer-related death worldwide… few therapeutic options are available… we investigated the effects of cannabinoids–a novel family of potential anticancer agents–on the growth of HCC. We found that Δ(9)-tetrahydrocannabinol (Δ(9)-THC, the main active component of Cannabis sativa)… reduced the viability of the human HCC cell lines…cannabinoids were also able to inhibit tumor growth… Our findings may contribute to the design of new therapeutic strategies for the management of HCC.”

http://www.ncbi.nlm.nih.gov/pubmed/21475304