The Immune Endocannabinoid System of the Tumor Microenvironment

ijms-logo“Leukocytes are part of the tumor microenvironment (TME) and are critical determinants of tumor progression. Because of the immunoregulatory properties of cannabinoids, the endocannabinoid system (ECS) may have an important role in shaping the TME.

Members of the ECS, an entity that consists of cannabinoid receptors, endocannabinoids and their synthesizing/degrading enzymes, have been associated with both tumor growth and rejection. Immune cells express cannabinoid receptors and produce endocannabinoids, thereby forming an “immune endocannabinoid system”. Although in vitro effects of exogenous cannabinoids on immune cells are well described, the role of the ECS in the TME, and hence in tumor development and immunotherapy, is still elusive.

This review/opinion discusses the possibility that the “immune endocannabinoid system” can fundamentally influence tumor progression. The widespread influence of cannabinoids on immune cell functions makes the members of the ECS an interesting target that could support immunotherapy.”

https://pubmed.ncbi.nlm.nih.gov/33255584/

“Anti-tumour actions of cannabinoids.” https://www.ncbi.nlm.nih.gov/pubmed/30019449

https://www.mdpi.com/1422-0067/21/23/8929

The effect of cannabidiol on canine neoplastic cell proliferation and MAP Kinase activation during autophagy and apoptosis

“Low tetrahydrocannabinol Cannabis sativa products, also known as hemp products, have become widely available and their use in veterinary patients has become increasingly popular. Despite prevalence of use, the veterinary literature is lacking and evidence-based resource for cannabinoid efficacy.

The most prevailing cannabinoid found in hemp is cannabidiolic acid (CBDA) and becomes cannabidiol (CBD) during heat extraction; CBD has been studied for its direct anti-neoplastic properties alone and in combination with standard cancer therapies, yielding encouraging results.

The objectives of our study were to explore the anti-proliferative and cell death response associated with in vitro treatment of canine cancer cell lines with CBD alone and combination with common chemotherapeutics, as well as investigation into major proliferative pathways (e.g. p38, JNK, AKT, mTOR) potentially involved in the response to treatment with CBD.

CBD significantly reduced canine cancer cell proliferation far better than cannabidiolic acid (CBDA) across five canine neoplastic cell lines when treated with concentrations ranging from 2.5-10 μg/mL. Combinatory treatment with CBD and vincristine reduced cell proliferation in a synergistic or additive manner at anti-proliferative concentrations with less clear results using doxorubicin in combination with CBD. The cellular signaling effects of CBD treatment, showed that autophagy supervened induction of apoptosis and may be related to prompt induction of ERK and JNK phosphorylation prior to autophagy.

In conclusion, CBD is effective at hindering cell proliferation and induction of autophagy and apoptosis rapidly across neoplastic cell lines and further clinical trials are needed to understand its efficacy and interactions with traditional chemotherapy.”

https://pubmed.ncbi.nlm.nih.gov/33247539/

https://onlinelibrary.wiley.com/doi/10.1111/vco.12669

Cannabis and its Constituents for Cancer: History, Biogenesis, Chemistry and Pharmacological Activities

Pharmacological Research “Cannabis has long been used for healing and recreation in several regions of the world. Over 400 bioactive constituents, including more than 100 phytocannabinoids, have been isolated from this plant. The non-psychoactive cannabidiol (CBD) and the psychoactive Δ9-tetrahydrocannabinol (Δ9-THC) are the major and widely studied constituents from this plant.

Cannabinoids exert their effects through the endocannabinoid system (ECS) that comprises cannabinoid receptors (CB1, CB2), endogenous ligands, and metabolizing enzymes. Several preclinical studies have demonstrated the potential of cannabinoids against leukemia, lymphoma, glioblastoma, and cancers of the breast, colorectum, pancreas, cervix and prostate.

Cannabis and its constituents can modulate multiple cancer related pathways such as PKB, AMPK, CAMKK-β, mTOR, PDHK, HIF-1α, and PPAR-γ. Cannabinoids can block cell growth, progression of cell cycle and induce apoptosis selectively in tumour cells. Cannabinoids can also enhance the efficacy of cancer therapeutics. These compounds have been used for the management of anorexia, queasiness, and pain in cancer patients.

Cannabinoid based products such as dronabinol, nabilone, nabiximols, and epidyolex are now approved for medical use in cancer patients. Cannabinoids are reported to produce a favourable safety profile. However, psychoactive properties and poor bioavailability limit the use of some cannabinoids. The Academic Institutions across the globe are offering training courses on cannabis. How cannabis and its constituents exert anticancer activities is discussed in this article. We also discuss areas that require attention and more extensive research.”

https://pubmed.ncbi.nlm.nih.gov/33246167/

https://www.sciencedirect.com/science/article/abs/pii/S1043661820316108?via%3Dihub

Cannabidiol enhances cytotoxicity of anti-cancer drugs in human head and neck squamous cell carcinoma

 Scientific Reports“Cannabidiol (CBD) has anti-tumorigenic activity. However, the anti-cancer effect of CBD on head and neck squamous cell carcinoma (HNSCC) remains unclear. The cytotoxicity of CBD on HNSCC was analyzed using cell survival and colony-forming assays in vitro.

CBD treatment significantly reduced migration/invasion and viability of HNSCC cells in a dose- and time-dependent manner. HNSCC mouse xenograft models revealed anti-tumor effects of CBD. Furthermore, combinational treatment with CBD enhanced the efficacy of chemotherapy drugs.

We identified CBD as a new potential anti-cancer compound for single or combination therapy of HNSCC.”

https://pubmed.ncbi.nlm.nih.gov/33244087/

In conclusion, our study determined the anti-tumorigenic potential of CBD. In addition, single treatment of CBD or co-treatment with chemotherapeutic agents promoted HNSCC cell death along with apoptosis and autophagy processes. Therefore, our study suggests that CBD can be an excellent therapeutic agent against HNSCC. Cannabidiol (CBD) is one of the components in the Cannabis sativa L. (marijuana) family of plants.”

https://www.nature.com/articles/s41598-020-77674-y

Prescribed medical cannabis in women with gynecologic malignancies: A single-institution survey-based study

Gynecologic Oncology Reports “Research within a gynecologic oncology population has lagged behind the uptake in use of medical cannabis for symptom control. This study seeks to evaluate patient experience with prescribed medical cannabis obtained through licensed dispensaries in women with gynecologic malignancies.

A 43-item survey exploring patient experience with medical cannabis was administered to women with gynecologic malignancies who used medical cannabis prescribed by a gynecologic oncologist. Thirty-six eligible patients were approached for consent, and 31 patients returned completed surveys (86%). Ninety-three percent had advanced or recurrent disease; 74% were receiving chemotherapy or immunotherapy.

Eighty-three percent reported medical cannabis provided relief from cancer or treatment-related symptoms including decreased appetite (41%), insomnia (41%), neuropathy (41%), anxiety (35%), nausea (29%), joint pain (29%), bone pain (29%), abdominal pain (25%), and depression (19%). Eighty percent of patients reported medical cannabis worked the same or better than other traditional medications for management of their cancer or treatment-related symptoms, and 83% reported medical cannabis had an equivalent or better side effect profile.

Of the subset of patients using medical cannabis for pain, 63% reported a reduction in opioid use. Patients perceive that medical cannabis was useful for relief of cancer and treatment-related symptoms, suggesting medical cannabis may be a reasonable alternative or adjunct therapy. Medical cannabis was well tolerated and may have the potential to improve neuropathic pain and decrease opioid use.”

https://pubmed.ncbi.nlm.nih.gov/33204797/

“Patients with gynecologic malignancies perceive medical cannabis relieves multiple cancer-related symptoms. Medical cannabis is well-tolerated and perceived to have a favorable side effect profile. Patients using medical cannabis for pain control report an associated reduction in opioid use.”

https://www.sciencedirect.com/science/article/pii/S2352578920301338?via%3Dihub

Preliminary assessment of medical cannabis consumption by cancer survivors

Complementary Therapies in Medicine “Objectives: To assess the motivation of cancer survivors to consume medical cannabis and to assess the patterns of use, perceived efficacy, as well as side and adverse effects.

Results: The mean monthly dosage of cannabis consumed was 42.4 grams; 95.8% of respondents reported not consuming cannabis regularly before being diagnosed with cancer; the most common way of administration was smoking, and most of the participants reported taking cannabis throughout the day. The most common symptoms for which participants took medical cannabis were pain (n = 169, 88.9%), sleeping disorder (n = 144, 75.8%) and anxiety (n = 79, 41.6%). Twenty patients (10.5%) reported on mild side (or adverse) effects.

Conclusions: This study indicates that cancer survivors may indeed consume cannabis for symptom relief, and not merely for recreational purposes. Although our findings point to perceived safety and efficacy of medical cannabis for cancer survivors, more research is needed to study the adequate role that cannabis may have for treating symptoms associated with cancer survivorship.”

https://pubmed.ncbi.nlm.nih.gov/33197667/

“In conclusion, despite the many challenges and uncertainties, cannabis is being slowly diffused into healthcare. Survivors who have ongoing symptoms as a result of their prior treatments should be carefully assessed as to whether there is a medical need for which cannabis may be helpful. Indeed, patients and physicians should establish and maintain a therapeutic alliance in which medical needs and potential treatments, including medical cannabis, are honestly discussed and mutually considered and agreed upon.”

https://www.sciencedirect.com/science/article/pii/S0965229920318598?via%3Dihub

Cannabidiol (CBD) as a Promising Anti-Cancer Drug

cancers-logo“Recently, cannabinoids, such as cannabidiol (CBD) and Δ9 -tetrahydrocannabinol (THC), have been the subject of intensive research and heavy scrutiny. Cannabinoids encompass a wide array of organic molecules, including those that are physiologically produced in humans, synthesized in laboratories, and extracted primarily from the Cannabis sativa plant. These organic molecules share similarities in their chemical structures as well as in their protein binding profiles. However, pronounced differences do exist in their mechanisms of action and clinical applications, which will be briefly compared and contrasted in this review. The mechanism of action of CBD and its potential applications in cancer therapy will be the major focus of this review article.”

https://pubmed.ncbi.nlm.nih.gov/33143283/

“The use of cannabinoids containing plant extracts as herbal medicine can be traced back to as early as 500 BC. In recent years, the medical and health-related applications of one of the non-psychotic cannabinoids, cannabidiol or CBD, has garnered tremendous attention. In this review, we will discuss the most recent findings that strongly support the further development of CBD as a promising anti-cancer drug.”

https://www.mdpi.com/2072-6694/12/11/3203

Cannabinoids Inhibited Pancreatic Cancer via P-21 Activated Kinase 1 Mediated Pathway

ijms-logo“The anti-cancer effects of cannabinoids including CBD (Cannabidiol) and THC ((-)-trans-∆9-tetrahydrocannabinol) have been reported in the case of pancreatic cancer (PC).

The connection of these cannabinoids to KRas oncogenes that mutate in more than 90% of PC, and their effects on PD-L1, a key target of immune checkpoint blockade, have not been thoroughly investigated. Using cell lines and mouse models of PC, the effects of CBD and THC on cancer growth, the interaction between PC cells and a stromal cell, namely pancreatic stellate cells (PSCs), and the mechanism(s) involved were determined by cell-based assays and mouse study in vivo.

CBD and THC inhibited the proliferation of PC, PSC, and PSC-stimulated PC cells. They also suppressed pancreatic tumour growth in mice. Furthermore, CBD and/or THC reduced the expression of PD-L1 by either PC or PSC cells. Knockout of p-21 activated kinase 1 (PAK1, activated by KRas) in PC and PSC cells and, in mice, dramatically decreased or blocked these inhibitory effects of CBD and/or THC.

These results indicated that CBD and THC exerted their inhibitions on PC and PSC via a p-21 activated kinase 1 (PAK1)-dependent pathway, suggesting that CBD and THC suppress Kras activated pathway by targeting PAK1. The inhibition by CBD and THC of PD-L1 expression will enhance the immune checkpoint blockade of PC.”

https://pubmed.ncbi.nlm.nih.gov/33126623/

https://www.mdpi.com/1422-0067/21/21/8035

Update on cannabis and cannabinoids for cancer pain

Current Issue Cover Image “The prevalence of cancer pain will continue to rise as pain is common among the survivorship and general cancer population. As interest in cannabis and cannabinoids for medicinal use including pain management continues to rise, there is growing need to update and review the current state of evidence for their use. The literature was searched for articles in English with key words cannabis, cannabinoids, and cancer pain. The sources of articles were PubMed, Embase, and open Google search.

Recent findings: In a double-blind randomized placebo-controlled trial including a 3-week treatment period of nabiximol for advanced cancer patients with pain refractory to optimized opiate therapy, improvements in average pain were seen in the intention to treat population (P = 0.0854) and per- protocol population (P = 0.0378).

Summary: To date, preclinical data has demonstrated evidence to suggest promising potential for cancer pain and the urgent need to translate this into clinical practice. Unfortunately, due to limited data, for adults with advanced cancer being treated with opiate therapy, the addition of cannabis or cannabinoids is not currently supported to address cancer pain effectively.”

https://pubmed.ncbi.nlm.nih.gov/33110020/

https://journals.lww.com/co-anesthesiology/Abstract/2020/12000/Update_on_cannabis_and_cannabinoids_for_cancer.19.aspx

Cannabinoid Receptor Subtype 2 (CB2R) in a Multitarget Approach: Perspective of an Innovative Strategy in Cancer and Neurodegeneration

 Go to Volume 0, Issue 0“The cannabinoid receptor subtype 2 (CB2R) represents an interesting and new therapeutic target for its involvement in the first steps of neurodegeneration as well as in cancer onset and progression.

Several studies, focused on different types of tumors, report a promising anticancer activity induced by CB2R agonists due to their ability to reduce inflammation and cell proliferation. Moreover, in neuroinflammation, the stimulation of CB2R, overexpressed in microglial cells, exerts beneficial effects in neurodegenerative disorders.

With the aim to overcome current treatment limitations, new drugs can be developed by specifically modulating, together with CB2R, other targets involved in such multifactorial disorders.

Building on successful case studies of already developed multitarget strategies involving CB2R, in this Perspective we aim at prompting the scientific community to consider new promising target associations involving HDACs (histone deacetylases) and σ receptors by employing modern approaches based on molecular hybridization, computational polypharmacology, and machine learning algorithms.”

https://pubmed.ncbi.nlm.nih.gov/33094613/

https://pubs.acs.org/doi/10.1021/acs.jmedchem.0c01357

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