Cannabinoid signalling in glioma cells

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“Cannabinoids, originally derived from Cannabis sativa, as well as their endogenous and synthetic counterparts, were shown to induce apoptosis of glioma cells in vitro and tumour regression in vivo via their specific receptors, cannabinoid receptors CB1 and/or CB2.

CB2 are abnormally expressed in human gliomas and glioma cell lines. Most of the analysed gliomas expressed significant levels of CB2 receptor and the extent of CB2 expression in the tumour specimens was related to tumour malignancy.

A synthetic cannabinoid, WIN 55,212-2, down-regulated the Akt and Erk signalling pathways in C6 glioma cells that resulted in reduction of phosphorylated Bad levels, mitochondrial depolarization and activation of caspase cascade leading to apoptosis.

We examined whether synthetic cannabinoids with different receptor specificity: WIN55,212-2 (a non-selective CB1/CB2 agonist) and JWH133 (a CB2-selective agonist) affect survival of four human glioma cell lines and three primary human glioma cell lines.

WIN-55,212-2 decreased cell viability in all examined cell lines and induced cell death. Susceptibility of the cells to JWH133 treatment correlated with the CB2 expression. Cannabinoids triggered a decrease of mitochondrial membrane potential, cleavage of caspase-9 and effector caspases.

Induction of cell death by cannabinoid treatment led to the generation of a pro-apoptotic sphingolipid ceramide and disruption of signalling pathways crucial for regulation of proliferation and survival. Increased ceramide levels induced ER-stress and autophagy in drug-treated glioblastoma cells.

We conclude that cannabinoids are efficient inhibitors of human glioma cells growth, once the cells express specific type of cannabinoid receptor.”

http://springerplus.springeropen.com/articles/10.1186/2193-1801-4-S1-L11

Activation of the orphan receptor GPR55 by lysophosphatidylinositol promotes metastasis in triple-negative breast cancer.

Image result for Oncotarget.“The orphan G protein-coupled receptor GPR55 has been directly or indirectly related to basic alterations that drive malignant growth: uncontrolled cancer cell proliferation, sustained angiogenesis, and cancer cell adhesion and migration. However, little is known about the involvement of this receptor in metastasis.

Here, we show that elevated GPR55 expression in human tumors is associated with the aggressive basal/triple-negative breast cancer population, higher probability to develop metastases, and therefore poor patient prognosis. Activation of GPR55 by its proposed endogenous ligand lysophosphatidylinositol confers pro-invasive features on breast cancer cells both in vitro and in vivo. Specifically, this effect is elicited by coupling to Gq/11 heterotrimeric proteins and the subsequent activation, through ERK, of the transcription factor ETV4/PEA3.

Together, these data show that GPR55 promotes breast cancer metastasis, and supports the notion that this orphan receptor may constitute a new therapeutic target and potential biomarker in the highly aggressive triple-negative subtype.”

http://www.ncbi.nlm.nih.gov/pubmed/27340777

Cannabimimetic Drugs: Recent Patents in Central Nervous System Disorders.

“Agents acting via cannabinoid receptors have been widely developed; starting from the chemical structure of phytocannabinoids isolated from cannabis sativa plant, specific and selective compounds of these receptors have been produced ranging from partial to full agonists and /or antagonists endowed with different potency.

The enhanced interest on developing such classes of drugs is due to the beneficial properties widely reported by both anecdotal reports and scientific studies describing the potential medicinal use of cannabinoids and their derivatives in numerous pathological conditions in both in vitro and in vivo models.

The use of these drugs has been found to be of benefit in a wide number of neurological and neuropsychiatric disorders, and in many other diseases ranging from cancer, atherosclerosis, stroke, hypertension, inflammatory related disorders, and autoimmune diseases, just to mention some.

In particular, being the cannabinoid CB1 receptor a central receptor expressed by neurons of the central nervous system, the attention for the treatment of neurological diseases has been mainly focused on compounds acting via this receptor, however some of these compounds has been showed to act by alternative pathways in some cases unrelated to CB1 receptors.

Nonetheless, endocannabinoids are potent regulators of the synaptic function in the central nervous system and their levels are modulated in neurological diseases.

In this study, we focused on endocannabinoid mechanism of action in neuronal signaling and on cannabimimetic drug potential application in neurological disorders.

Finally, novel patents on cannabis-based drugs with applicability in central nervous system disorders are highlighted, to suggest future potential therapeutic utility of derivatives of this ancient plant.”

http://www.ncbi.nlm.nih.gov/pubmed/27334611

The cannabinoid WIN 55,212-2 prevents neuroendocrine differentiation of LNCaP prostate cancer cells.

“Neuroendocrine (NE) differentiation represents a common feature of prostate cancer and is associated with accelerated disease progression and poor clinical outcome. Nowadays, there is no treatment for this aggressive form of prostate cancer.

The aim of this study was to determine the influence of the cannabinoid WIN 55,212-2 (WIN, a non-selective cannabinoid CB1 and CB2 receptor agonist) on the NE differentiation of prostate cancer cells.

Taken together, we demonstrate that PI3K/Akt/AMPK might be an important axis modulating NE differentiation of prostate cancer that is blocked by the cannabinoid WIN, pointing to a therapeutic potential of cannabinoids against NE prostate cancer.”

http://www.ncbi.nlm.nih.gov/pubmed/27324222

CANNABIS CHEMICALS STOP PROSTATE CANCER GROWTH

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“ACTIVE chemicals in cannabis have been shown to halt prostate cancer cell growth according to research published in the British Journal of Cancer*.

Researchers from the University of Alcala, in Madrid tested the effects of the active chemicals in cannabis called cannabinoids** on three human prostate cancer cell lines – called PC-3, DU-a45 and LNCaP.

The prostate cancer cells carry molecular ‘garages’- called receptors- in which cannabinoids can ‘park’.

The scientists showed for the first time that if cannabinoids ‘park’ on a receptor called CB2, the cancer cells stop multipyling.

“This research suggest that prostate cancer cells might stop growing if they are treated with chemicals found in cannabis but more work needs to be done to explore the potential of the cannabinoids in treatment.”

To confirm the findings the scientists switched off the CB2 receptors – or ‘closed the garage doors’- on the prostate cells. When cannabinoids were then added to cells without the CB2 receptor, the prostate cancer cells carried on dividing and growing. This suggests that cannabinoids connect with the CB2 receptors on prostate cancer cells to stop cell division and spread.

Professor Ines Diaz-Laviada, study author at the University of Alcala said: “Our research shows that there are areas on prostate cancer cells which can recognise and talk to chemicals found in cannabis called cannabinoids. These chemicals can stop the division and growth of prostate cancer cells and could become a target for new research into potential drugs to treat prostate cancer.””

http://www.nature.com/bjc/press_releases/p_r_aug09_6605248.html

https://www.news-medical.net/news/20090821/Cannabis-chemicals-stop-prostate-cancer-growth.aspx

Inhibition of human tumour prostate PC-3 cell growth by cannabinoids R(+)-Methanandamide and JWH-015: Involvement of CB2

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“We have previously shown that cannabinoids induce growth inhibition and apoptosis in prostate cancer PC-3 cells, which express high levels of cannabinoid receptor types 1 and 2 (CB1 and CB2). In this study, we investigated the role of CB2 receptor in the anti-proliferative action of cannabinoids and the signal transduction triggered by receptor ligation.

This study defines the involvement of CB2-mediated signalling in the in vivo and in vitro growth inhibition of prostate cancer cells and suggests that CB2 agonists have potential therapeutic interest and deserve to be explored in the management of prostate cancer.

Cannabinoids, the active components of Cannabis sativa and their derivatives, exert a wide spectrum of modulatory actions and pharmacological activities in the brain as well as in the periphery, and therefore, the therapeutic potential of cannabinoids has gained much attention during the past few years. One of the most exciting areas of current research in the therapeutic potential of cannabinoids is cancer.

Recent evidence suggests that cannabinoids are powerful regulators of cell growth and differentiation. They have been shown to exert anti-tumoural effects by decreasing viability, proliferation, adhesion and migration on various cancer cells, thereby suggesting the potential use of cannabinoids in the treatment of gliomas, prostate and breast cancers and malignancies of immune origin.

Overall, our data show a role for the cannabinoid receptor CB2 in the anti-tumour effect of cannabinoids on prostate cells in vitroand in vivo. There is considerable interest in the application of selective CB2 receptor agonists, which are devoid of typical marijuana-like psychoactive properties of CB1 agonists, for future cannabinoid-based anticancer therapies. Therefore, our findings point to the potential application of cannabinoid receptor type 2 ligands as anti-tumour agents in prostate cancer.”

Phytochemicals as adjunctive with conventional anticancer therapies.

“Cancer is defined as the abnormal proliferations of cells which could occur in any tissue and can cause life-threatening malignancies with high financial costs for both patients and health care system. Plant-derived secondary metabolites are shown to have positive role in various diseases and conditions. The aim of the present study is to summarize clinical evidences on the benefits of phytochemicals as adjuvant therapy along with conventional anticancer therapies.

The findings showed that positive effects of phytochemicals are due to their direct anti-carcinogenic activity, induction of relief in cancer complications, as well as their protective role against side effects of conventional chemotherapeutic agents.

Results obtained from current review demonstrated that numerous phytochemical agents from different chemical categories including alkaloid, benzopyran, coumarin, carotenoid, diarylheptanoid, flavonoid, indole, polysaccharide, protein, stilbene, terpene, and xanthonoid possess therapeutic effect in patients with different types of cancer. Polyphenols are the most studied components. Curcumin, ginsenosides, lycopene, homoharringtonine, aviscumine, and resveratrol are amongst the major components with remarkable volumes of clinical evidence indicating their direct anticancer activities in different types of cancer including hepatocarcinoma, prostate cancer, leukemia and lymphoma, breast and ovarian cancer, and gastrointestinal cancers.

Cannabinoids, cumarin, curcumin, ginsenosides, epigallocatechin gallate, vitexin, and salidroside are phytochemicals with significant alleviative effect on synthetic chemotherapy-induced toxicities.”

http://www.ncbi.nlm.nih.gov/pubmed/27262332

Endocannabinoid system: a promising therapeutic target for the treatment of haematological malignancies?

“The therapeutic properties of cannabinoids are well-known since ancient years.

Growing evidence exist on endocannabinoid system (ECS) modulation related with human tumorigenesis.

Taking into account the substantial role of ECS on immune cell regulation, the present review is aimed to summarize the emerging evidence concerning cannabinoid receptor (CBR) expression and cannabinoid ligand effects on haematological malignancies.

CONCLUSIONS:

Most of cannabinoid actions, mainly CB2R-mediated against haematopoietic malignant cells, seems promising, as inhibition of cell proliferation and apoptosis and paraptosis induction have been documented.

Cannabinoid ligands appear to activate rudimentary pathways for cell survival, such as ERK, JNK, p38 MAPK, and to induce caspase synthesis, in vitro. Such data are strongly recommended to be confirmed by in vivo experiments with emphasis on cannabinoid ligands’ bioavailability and phytocannabinoid psychotropic properties.

The preliminary antitumoral ECS effects and their relative lack of important side effects render ECS a promising therapeutic target for the treatment of haematological malignancies.”

http://www.ncbi.nlm.nih.gov/pubmed/27237820

The Use of Medical Marijuana in Cancer.

“The use of medical marijuana in cancer care presents a dilemma for both patients and physicians. The scientific evidence is evolving, yet much of the known information is still insufficient to adequately inform patients as to risks and benefits. In addition, evidence-based dosing and administration information on medical marijuana is lacking. Medical marijuana is now legal, on some level, in 24 states plus the District of Columbia, yet is not legal on the federal level. This review addresses the current state of the research, including potential indications, risks and adverse effects, preliminary data on anticancer effects, as well as legal and quality issues. A summary of the clinical trials underway on medical marijuana in the oncology setting is discussed.”

http://www.ncbi.nlm.nih.gov/pubmed/27215434

Cannabinoid receptor 2 (CB2) agonists and antagonists: a patent update.

“Modulation of the CB2 receptor is an interesting approach for pain and inflammation, arthritis, addictions, neuroprotection, and cancer, among other possible therapeutic applications, and is devoid of central side effects.

Structural diversity of CB2 modulator scaffolds characterized the patent literature.

Several CB2 agonists reached clinical Phase II for pain management and inflammation.

Other therapeutic applications need to be explored such as neuroprotection and/or neurodegeneration.”

http://www.ncbi.nlm.nih.gov/pubmed/27215781