GPR3, GPR6, and GPR12 as novel molecular targets: their biological functions and interaction with cannabidiol.

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“The G protein-coupled receptors 3, 6, and 12 (GPR3, GPR6, and GPR12) comprise a family of closely related orphan receptors with no confirmed endogenous ligands. These receptors are constitutively active and capable of signaling through G protein-mediated and non-G protein-mediated mechanisms. These orphan receptors have previously been reported to play important roles in many normal physiological functions and to be involved in a variety of pathological conditions.

Although they are orphans, GPR3, GPR6, and GPR12 are phylogenetically most closely related to the cannabinoid receptors. Using β-arrestin2 recruitment and cAMP accumulation assays, we recently found that the nonpsychoactive phytocannabinoid cannabidiol (CBD) is an inverse agonist for GPR3, GPR6, and GPR12.

This discovery highlights these orphan receptors as potential new molecular targets for CBD, provides novel mechanisms of action, and suggests new therapeutic uses of CBD for illnesses such as Alzheimer’s disease, Parkinson’s disease, cancer, and infertility. Furthermore, identification of CBD as a new inverse agonist for GPR3, GPR6, and GPR12 provides the initial chemical scaffolds upon which potent and efficacious agents acting on these receptors can be developed, with the goal of developing chemical tools for studying these orphan receptors and ultimately new therapeutic agents.”

https://www.ncbi.nlm.nih.gov/pubmed/29941868

https://www.nature.com/articles/s41401-018-0031-9

Appraising the “entourage effect”: antitumor action of a pure cannabinoid versus a botanical drug preparation in preclinical models of breast cancer.

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“Breast cancer is the second leading cause of death among women. Although early diagnosis and development of new treatments have improved their prognosis, many patients present innate or acquired resistance to current therapies. New therapeutic approaches are therefore warranted for the management of this disease.

Extensive preclinical research has demonstrated that cannabinoids, the active ingredients of Cannabis sativa, trigger antitumor responses in different models of cancer. Most of these studies have been conducted with pure compounds, mainly Δ9-tetrahydrocannabinol (THC).

The cannabis plant, however, produces hundreds of other compounds with their own therapeutic potential and the capability to induce synergic responses when combined, the so-called “entourage effect”.

Here, we compared the antitumor efficacy of pure THC with that of a botanical drug preparation (BDP). The BDP was more potent than pure THC in producing antitumor responses in cell culture and animal models of ER+/PR+, HER2+ and triple-negative breast cancer. This increased potency was not due to the presence of the 5 most abundant terpenes in the preparation.

While pure THC acted by activating cannabinoid CB2 receptors and generating reactive oxygen species, the BDP modulated different targets and mechanisms of action. The combination of cannabinoids with estrogen receptor- or HER2-targeted therapies (tamoxifen and lapatinib, respectively) or with cisplatin, produced additive antiproliferative responses in cell cultures. Combinations of these treatments in vivo showed no interactions, either positive or negative.

Together, our results suggest that standardized cannabis drug preparations, rather than pure cannabinoids, could be considered as part of the therapeutic armamentarium to manage breast cancer.”

Assessment of Cannabinoids Agonist and Antagonist in Invasion Potential of K562 Cancer Cells

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“The prominent hallmark of malignancies is the metastatic spread of cancer cells. Recent studies have reported that the nature of invasive cells could be changed after this phenomenon, causing chemotherapy resistance.

It has been demonstrated that the up-regulated expression of matrix metalloproteinase (MMP) 2/MMP-9, as a metastasis biomarker, can fortify the metastatic potential of leukemia.

Furthermore, investigations have confirmed the inhibitory effect of cannabinoid and endocannabinoid on the proliferation of cancer cells in vitro and in vivo.

Our findings clarifies that CB1 receptors are responsible for anti-invasive effects in the K562 cell line.”

https://www.ncbi.nlm.nih.gov/pubmed/29883990

The importance of 15-lipoxygenase inhibitors in cancer treatment.

Cancer and Metastasis Reviews

“Cancer-targeted therapy is an expanding and successful approach in treatment of many types of cancers. One of the main categories of targeted therapy is use of small molecule inhibitors. 15-Lipoxygenase (15-LOX) is an enzyme which reacts with polyunsaturated fatty acids and produces metabolites that are implicated in many important human diseases, such as cancer.

Considering the role of 15-LOX (mainly 15-LOX-1) in the progression of some cancers, the discovery of 15-LOX inhibitors could potentially lead to development of novel cancer therapeutics and it can be claimed that 15-LOX inhibitors might be suitable as chemotherapy agents in the near future.

This article reviews relevant publications on 15-LOX inhibitors with focus on their anticancer activities in vitro and in vivo. Many 15-LOX inhibitors have been reported for which separate studies have shown their anticancer activities. This review paves the way to further explore the mechanism of their antiproliferative effects via 15-LOX inhibition.”

“Cannabidiol-2′,6′-Dimethyl Ether, a Cannabidiol Derivative, Is a Highly Potent and Selective 15-Lipoxygenase Inhibitor”  http://dmd.aspetjournals.org/content/37/8/1733.long

“Δ9-tetrahydrocannabinol and its major metabolite Δ9-tetrahydrocannabinol-11-oic acid as 15-lipoxygenase inhibitors.”  https://www.ncbi.nlm.nih.gov/pubmed/20891010

Anti-Tumorigenic Properties of Omega-3 Endocannabinoid Epoxides.

Journal of Medicinal Chemistry

“Accumulating studies have linked inflammation to tumor progression.

Dietary omega-3 fatty acids including docosahexaenoic acid (DHA) have been shown to suppress tumor growth through their conversion to epoxide metabolites. Alternatively, DHA is converted enzymatically into docosahexaenoylethanolamide (DHEA), an endocannabinoid with anti-proliferative activity.

Recently, we reported a novel class of anti-inflammatory DHEA-epoxides (EDP-EAs) that contain both ethanolamide and epoxide moieties. Herein we evaluate the anti-tumorigenic properties of EDP-EAs in an osteosarcoma model.

First, we show ~80% increase in EDP-EAs in metastatic lungs versus normal mouse lungs. We found significant differences in the apoptotic and anti-migratory potency of the different EDP-EA regioisomers, which are partly mediated through cannabinoid receptor 1 (CB1).

Furthermore, we synthesized derivatives of the most pro-apoptotic regioisomer. These derivatives had reduced hydrolytic susceptibility to fatty acid-amide hydrolase and increased CB1 binding.

Collectively, we report a novel class of EDP-EAs that exhibit anti-angiogenic, anti-tumorigenic and anti-migratory properties in osteosarcoma.”

https://www.ncbi.nlm.nih.gov/pubmed/29856219

https://pubs.acs.org/doi/10.1021/acs.jmedchem.8b00243

“Omega-3 Fatty Byproducts May Have Anticancer Effects.https://scienceblog.com/502227/omega-3-fatty-byproducts-may-have-anticancer-effects/
“Products of omega-3 fatty acid metabolism may have anticancer effects, study shows” https://medicalxpress.com/news/2018-07-products-omega-fatty-acid-metabolism.html
“Omega-3-derived cannabinoid may stop cancer. New research suggests that the body’s natural pain-killer, the “endocannabinoid system,” may also have cancer-fighting properties when “activated” by omega-3 fatty acids.” https://www.medicalnewstoday.com/articles/322482.php
“Products of omega-3 fatty acid metabolism may have anticancer effects” https://www.sciencedaily.com/releases/2018/07/180713220137.htm

Medical Oncologists’ Beliefs, Practices, and Knowledge Regarding Marijuana Used Therapeutically: A Nationally Representative Survey Study

Journal of Clinical Oncology

“Although almost every state medical marijuana (MM) law identifies cancer as a qualifying condition, little research supports MM’s use in oncology. We hypothesized that the discrepancy between these laws and the scientific evidence base poses clinical challenges for oncologists. Oncologists’ beliefs, knowledge, and practices regarding MM were examined in this study.

In November 2016, we mailed a survey on MM to a nationally-representative, random sample of 400 medical oncologists. Main outcome measures included whether oncologists reported discussing MM with patients, recommended MM clinically in the past year, or felt sufficiently informed to make such recommendations. The survey also queried oncologists’ views on MM’s comparative effectiveness for several conditions (including its use as an adjunct to standard pain management strategies) and its risks compared with prescription opioids. Bivariate and multivariate analyses were performed using standard statistical techniques.

The overall response rate was 63%. Whereas only 30% of oncologists felt sufficiently informed to make recommendations regarding MM, 80% conducted discussions about MM with patients, and 46% recommended MM clinically. Sixty-seven percent viewed it as a helpful adjunct to standard pain management strategies, and 65% thought MM is equally or more effective than standard treatments for anorexia and cachexia.

Our findings identify a concerning discrepancy between oncologists’ self-reported knowledge base and their beliefs and practices regarding MM. Although 70% of oncologists do not feel equipped to make clinical recommendations regarding MM, the vast majority conduct discussions with patients about MM and nearly one-half do, in fact, recommend it clinically. A majority believes MM is useful for certain indications. These findings are clinically important and suggest critical gaps in research, medical education, and policy regarding MM.”

http://ascopubs.org/doi/10.1200/JCO.2017.76.1221

“Survey: Oncologists Believe Medical Marijuana to be Equally or More Effective Than Conventional Cancer Treatments”  http://www.thedailychronic.net/2018/90645/survey-oncologists-believe-medical-cannabis-equally-effective-conventional-treatments/

The role of lipid signaling in the progression of malignant melanoma.

Cancer and Metastasis Reviews

“In the past decades, a vast amount of data accumulated on the role of lipid signaling pathways in the progression of malignant melanoma, the most metastatic/aggressive human cancer type. Genomic studies identified that PTEN loss is the leading factor behind the activation of the PI3K-signaling pathway in melanoma, mutations of which are one of the main resistance mechanisms behind target therapy failures. On the other hand, illegitimate expressions of megakaryocytic genes p12-lipoxyganse, cyclooxygenase-2, and phosphodiestherase-2/autotaxin (ATX) are mostly involved in the regulation of motility signaling in melanoma through various G-protein-coupled bioactive lipid receptors. Furthermore, endocannabinoid signaling can also be a novel paracrine survival factor in melanoma. Last but not least, prenylation inhibitors acting even on mutated small GTP-ases, such as NRAS of melanoma may offer novel therapeutic opportunities. As regards melanoma, the most effective therapy nowadays is immunotherapy, with the resistance mechanisms also possibly involving the lipid signaling activities of melanoma cells, which further supports the idea of their being therapeutic targets.”

∆9-tetrahydrocannabinol inhibits epithelial-mesenchymal transition and metastasis by targeting matrix metalloproteinase-9 in endometrial cancer.

Journal Cover

“Limited therapeutic interventions are clinically available for treating aggressive endometrial cancer (EC). Therefore, effective therapies are urgently required.

Therefore, the present study investigated the role of ∆9-tetrahydrocannabinol (THC), which is reported to impact proliferative and migratory activities during impairment of cancer progression.

In the present study, cell migration in response to THC was measured using transwell assays. Using western blot analysis, the levels of cannabinoid receptors in EC tissues were detected and pathways leading to the inhibition of cell migration by THC on human EC cells were determined.

Results suggested that cannabinoid receptors were highly expressed in EC tissues.

Furthermore, THC inhibited EC cell viability and motility by inhibiting epithelial-mesenchymal transition (EMT) and downregulating matrix metalloproteinase-9 (MMP-9) gene expression in aggressive human EC cells.

The results have the potential to promote the development of novel compounds for the treatment of EC metastasis. The present findings suggest that THC may inhibit human EC cell migration through regulating EMT and MMP-9 pathways.”

https://www.ncbi.nlm.nih.gov/pubmed/29805589

https://www.spandidos-publications.com/10.3892/ol.2018.8407

Involvement of the CB2 cannabinoid receptor in cell growth inhibition and G0/G1 cell cycle arrest via the cannabinoid agonist WIN 55,212-2 in renal cell carcinoma.

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“The anti-tumor properties of cannabinoids have been investigated in many in vitro and in vivo studies. Many of these anti-tumor effects are mediated via cannabinoid receptor types 1 and 2 (CB1 and CB2), comprising the endocannabinoid system (ECS).

In this study, we investigated the ECS based on CB 1 and CB 2 receptor gene and protein expression in renal cell carcinoma (RCC) cell lines. In view of their further use for potential treatments, we thus investigated the roles of CB1 and CB2 receptors in the anti-proliferative action and signal transduction triggered by synthetic cannabinoid agonists [such as JWH-133 and WIN 55,212-2 (WIN-55)] in RCC cell lines.

RESULTS:

The CB1 and CB2 genes expression was shown by real-time PCR and flow cytometric and western blot analysis indicating a higher level of CB2 receptor as compared to CB1 in RCC cells. Immunocytochemical staining also confirmed the expression of the CB1 and CB2 proteins. We also found that the synthetic cannabinoid agonist WIN-55 exerted anti-proliferative and cytotoxic effects by inhibiting the growth of RCC cell lines, while the CB2 agonist JWH-133 did not. Pharmacologically blocking the CB1 and CB2 receptors with their respective antagonists SR141716A and AM-630, followed by the WIN-55 treatment of RCC cells allowed uncovering the involvement of CB2, which led to an arrest in the G0/G1 phase of the cell cycle and apoptosis.

CONCLUSIONS:

This study elucidated the involvement of CB2 in the in vitro inhibition of RCC cells, and future applications of CB2agonists in the prevention and management of RCC are discussed.

In summary, our study shows the involvement of CB2 receptor in the in vitro inhibition of RCC cells. This knowledge will be useful to unravel the future applications of CB2receptor and its agonists in the prevention and management of RCC.”

Cannabis for the Management of Cancer Symptoms: THC Version 2.0?

Cannabis and Cannabinoid Research cover image

“The landscape of medical cannabis is rapidly expanding. Cannabis preparations have been used in medicine for millennia, and now there is a strong renaissance in the study of their therapeutic properties.

The vast majority of controlled clinical trials that support the medical use of what is commonly known as “cannabis” or “marijuana” have actually been conducted with purified cannabinoids or a single extract of Cannabis sativa that contains an equimolecular proportion of Δ9-THC and CBD.

Based on these studies, THC/dronabinol (Marinol) and its synthetic analogue nabilone (Cesamet), as well as nabiximols (Sativex), are already approved by several regulatory agencies, including FDA, Health Canada, and EMA, as antiemetic, anticachexic, analgesic, or antispastic medicines.

This study provides a precious piece of information on the use of medical cannabis for the management of cancer symptoms.”

https://www.liebertpub.com/doi/10.1089/can.2018.0009