Anandamide inhibits Cdk2 and activates Chk1 leading to cell cycle arrest in human breast cancer cells.

“This study was designed to determine the molecular mechanisms underlying the anti-proliferative effect of the endocannabinoid anandamide on highly invasive human breast cancer cells, MDA-MB-231. We show that a metabolically stable analogue of anandamide, Met-F-AEA, induces an S phase growth arrest correlated with Chk1 activation, Cdc25A degradation and suppression of Cdk2 activity. These findings demonstrate that Met-F-AEA induced cell cycle blockade relies on modulated expression and activity of key S phase regulatory proteins. The observed mechanism of action, already reported for well-known chemotherapeutic drugs, provides strong evidence for a direct role of anandamide related compounds in the activation of cell cycle checkpoints.”

http://www.ncbi.nlm.nih.gov/pubmed/17055492

The anandamide analog, Met-F-AEA, controls human breast cancer cell migration via the RHOA/RHO kinase signaling pathway.

“The endocannabinoid system regulates cell proliferation and migration in human breast cancer cells. In this study, we showed that a metabolically stable analog of anandamide, 2-methyl-2′-F-anandamide (Met-F-AEA), inhibited the RHOA activity and caused a RHOA delocalization from the cell membrane to cytosol determining a decrease in actin stress fibers. Overexpression of a dominant negative of RHOA activity and treatment of these cells with a RHO-associated protein kinase (ROCK) inhibitor, Y 27632, mimicked Met-F-AEA effects on actin organization and cell migration. We suggest that the inhibitory effect of Met-F-AEA on tumor cell migration could be related to RHOA-ROCK-dependent signaling pathway.”

http://www.ncbi.nlm.nih.gov/pubmed/18676619

Anandamide inhibits the Wnt/β-catenin signalling pathway in human breast cancer MDA MB 231 cells.

“We previously showed that methyl-F-anandamide, a stable analogue of the anandamide, inhibited the growth and the progression of cultured human breast cancer cells. As accumulating evidences indicate that the constitutive activation of the canonical Wnt pathway in human breast cancer may highlight a key role for aberrant activation of the β-catenin-TCF cascade and tumour progression, we studied the anandamide effect on the key elements of Wnt pathway in breast cancer cells. In this study we described that the treatment of human breast cancer cells, MDA MB 231 cells, with methyl-F-anandamide reduced protein levels of β-catenin in the cytoplasmic and nuclear fractions inhibiting the transcriptional activation of T Cell Factor (TCF) responsive element (marker for β-catenin signalling). The anandamide treatment resulted in up-regulation of epithelial markers, like E-cadherin with a concomitant decrease in protein levels of mesenchymal markers, including vimentin and Snail1. We, furthermore, observed that the induction of experimental epithelial-mesenchymal transition by exposure to adriamycin in MCF7 human breast cancer cell line was inhibited by anandamide treatment. In the present study we reported a novel anticancer effect of anandamide involving the inhibition of epithelial-mesenchymal transition, a process triggered during progression of cancer to invasive state.”

http://www.ncbi.nlm.nih.gov/pubmed/22425263

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

Anandamide inhibits adhesion and migration of breast cancer cells.

“The endocannabinoid system regulates cell proliferation in human breast cancer cells. We reasoned that stimulation of cannabinoid CB1 receptors could induce a non-invasive phenotype in breast metastatic cells. In a model of metastatic spreading in vivo, the metabolically stable anandamide analogue, 2-methyl-2′-F-anandamide (Met-F-AEA), significantly reduced the number and dimension of metastatic nodes, this effect being antagonized by the selective CB1 antagonist SR141716A. In MDA-MB-231 cells, a highly invasive human breast cancer cell line, and in TSA-E1 cells, a murine breast cancer cell line, Met-F-AEA inhibited adhesion and migration on type IV collagen in vitro without modifying integrin expression: both these effects were antagonized by SR141716A. In order to understand the molecular mechanism involved in these processes, we analyzed the phosphorylation of FAK and Src, two tyrosine kinases involved in migration and adhesion. In Met-F-AEA-treated cells, we observed a decreased tyrosine phosphorylation of both FAK and Src, this effect being attenuated by SR141716A. We propose that CB1 receptor agonists inhibit tumor cell invasion and metastasis by modulating FAK phosphorylation, and that CB1 receptor activation might represent a novel therapeutic strategy to slow down the growth of breast carcinoma and to inhibit its metastatic diffusion in vivo.”

http://www.ncbi.nlm.nih.gov/pubmed/16343481

Endocannabinoids in endocrine and related tumours.

“The ‘endocannabinoid system’, comprising the cannabinoid CB1 and CB2 receptors, their endogenous ligands, endocannabinoids and the enzymes that regulate their biosynthesis and degradation, has drawn a great deal of scientist attention during the last two decades. The endocannabinoid system is involved in a broad range of functions and in a growing number of physiopathological conditions. Indeed, recent evidence indicates that endocannabinoids influence the intracellular events controlling the proliferation of numerous types of endocrine and related cancer cells, thereby leading to both in vitro and in vivo antitumour effects. In particular, they are able to inhibit cell growth, invasion and metastasis of thyroid, breast and prostate tumours. The chief events of endocannabinoids in cancer cell proliferation are reported highlighting the correspondent signalling involved in tumour processes: regulation of adenylyl cyclase, cyclic AMP-protein kinase-A pathway and MEK-extracellular signal-regulated kinase signalling cascade.

Up to date since the isolation and characterisation of the psychoactive component of Cannabis sativa, Δ9-tetrahydrocannabinol (Δ9-THC), about 60 different plant terpeno-phenols more or less related to THC have been isolated and defined cannabinoids. They include cannabidiol (CBD), cannabinol, cannabigerol and cannabichromene. The discovery of these principles stimulated the generation of a whole range of synthetic analogues that included not only compounds structurally similar to phytocannabinoids, but also analogues with different chemical structures, including classic and non-classic cannabinoids and aminoalkylindoles (Howlett et al. 2002) as well as the subsequently discovered endogenous arachidonic acid derivatives or endocannabinoids. The discovery of this family of endogenous cannabinoids (Devane et al. 1992, Mechoulam et al. 1995, Sugiura et al. 1995) has focused much attention on cannabinoids and their pharmacological properties during the last few years (Di Marzo et al. 2004).”

http://erc.endocrinology-journals.org/content/15/2/391.long

Crosstalk between Chemokine Receptor CXCR4 and Cannabinoid Receptor CB2 in Modulating Breast Cancer Growth and Invasion

“BACKGROUND:

Cannabinoids bind to cannabinoid receptors CB(1) and CB(2) and have been reported to possess anti-tumorigenic activity in various cancers. However, the mechanisms through which cannabinoids modulate tumor growth are not well known. In this study, we report that a synthetic non-psychoactive cannabinoid that specifically binds to cannabinoid receptor CB(2) may modulate breast tumor growth and metastasis by inhibiting signaling of the chemokine receptor CXCR4 and its ligand CXCL12. This signaling pathway has been shown to play an important role in regulating breast cancer progression and metastasis.

CONCLUSIONS/SIGNIFICANCE:

This study provides novel insights into the crosstalk between CB(2) and CXCR4/CXCL12-signaling pathways in the modulation of breast tumor growth and metastasis. Furthermore, these studies indicate that CB(2) receptors could be used for developing innovative therapeutic strategies against breast cancer.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3168464/

Disease modification of breast cancer-induced bone remodeling by cannabinoid 2 receptor agonists.

“Most commonly originating from breast malignancies, metastatic bone cancer causes bone destruction and severe pain. Although novel chemotherapeutic agents have increased life expectancy, patients are experiencing higher incidences of fracture, pain, and drug-induced side effects; furthermore, recent findings suggest that patients are severely under-treated for their cancer pain. Strong analgesics, namely opiates, are first-line therapy in alleviating cancer-related pain despite the severe side effects, including enhanced bone destruction with sustained administration.Bone resorption is primarily treated with bisphosphonates, which are associated with highly undesirable side-effects including nephrotoxicity and osteonecrosis of the jaw.In contrast, cannabinoid CB(2) receptor-specific agonists have been shown to reduce bone loss and stimulate bone formation in a model of osteoporosis.CB(2) agonists produce analgesia in both inflammatory and neuropathic pain models. Notably, mixed CB(1) /CB(2) agonists also demonstrate a reduction in ErbB2-driven breast cancer progression. Here we demonstrate for the first time that CB(2) agonists reduce breast cancer-induced bone pain, bone loss and breast cancer proliferation via cytokine/chemokine suppression.Studies utilized the spontaneously-occurring murine mammary cell line (66.1) implanted into the femur intramedullary space; measurements of spontaneous pain, bone loss and cancer proliferation were made. The systemic administration of a CB(2) agonist, JWH015, for seven days significantly attenuated bone remodeling, assuaged spontaneous pain and decreased primary tumor burden. CB(2) -mediated effects in vivo were reversed by concurrent treatment with a CB(2) antagonist/inverse agonist but not with a CB(1) antagonist/inverse agonist. In vitro, JWH015 reduced cancer cell proliferation and inflammatory mediators that have been shown to promote pain, bone loss and proliferation.Taken together, these results suggest CB(2) agonists as a novel treatment for breast cancer-induced bone pain, where disease modifications include a reduction in bone loss, suppression of cancer growth, attenuation of severe bone-pain and increased survival without the major side effects of current therapeutic options.”

http://www.ncbi.nlm.nih.gov/pubmed/22903605

Cannabinoids in the treatment of cancer.

“Cannabinoids, the active components of the hemp plant Cannabis sativa, along with their endogenous counterparts and synthetic derivatives, have elicited anti-cancer effects in many different in vitro and in vivo models of cancer. While the various cannabinoids have been examined in a variety of cancer models, recent studies have focused on the role of cannabinoid receptor agonists (both CB(1) and CB(2)) in the treatment of estrogen receptor-negative breast cancer. This review will summarize the anti-cancer properties of the cannabinoids, discuss their potential mechanisms of action, as well as explore controversies surrounding the results.”

http://www.ncbi.nlm.nih.gov/pubmed/19442435

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