The Anti-Tumorigenic Role of Cannabinoid Receptor 2 in Non-Melanoma Skin Cancer

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“Five million non-melanoma skin cancers occur globally each year, and it is one of the most common malignant cancers. The dysregulation of the endocannabinoid system, particularly cannabinoid receptor 2 (CB2), is implicated in skin cancer development, progression, and metastasis. Comparing wildtype (WT) to systemic CB2 knockout (CB2-/-) mice, we performed a spontaneous cancer study in one-year old mice, and subsequently used the multi-stage chemical carcinogenesis model, wherein cancer is initiated by 7,12-dimethylbenz[a]anthracene (DMBA) and promoted by 12-O-tetradecanoylphorbol-13-acetate (TPA). We found that aging CB2-/- mice have an increased incidence of spontaneous cancerous and precancerous skin lesions compared to their WT counterparts. In the DMBA/TPA model, CB2-/- developed more and larger papillomas, had decreased spontaneous regression of papillomas, and displayed an altered systemic immune profile, including upregulated CD4+ T cells and dendritic cells, compared to WT mice. Immune cell infiltration in the tumor microenvironment was generally low for both genotypes, although a trend of higher myeloid-derived suppressor cells was observed in the CB2-/- mice. CB2 expression in carcinogen-exposed skin was significantly higher compared to naïve skin in WT mice, suggesting a role of CB2 on keratinocytes. Taken together, our data show that endogenous CB2 activation plays an anti-tumorigenic role in non-melanoma skin carcinogenesis, potentially via an immune-mediated response involving the alteration of T cells and myeloid cells coupled with the modulation of keratinocyte activity.”

https://pubmed.ncbi.nlm.nih.gov/37175480/

“We show that endogenous CB2 activation lowers the risk for spontaneous cancer development in aging mice and papilloma development in a chemically-induced model of skin carcinogenesis. CB2 activation can modulate the systemic immune response and reduce tumorigenesis, either by an immune-mediated response involving the alteration of T cells and myeloid cells, or by the modulation of keratinocyte proliferation. This implies that CB2 could have an anti-tumorigenic role in skin cancer and serve as a potential treatment target.”

https://www.mdpi.com/1422-0067/24/9/7773

Neuronal Cannabinoid CB1 Receptors Suppress the Growth of Melanoma Brain Metastases by Inhibiting Glutamatergic Signalling

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“Melanoma is one of the deadliest forms of cancer. Most melanoma deaths are caused by distant metastases in several organs, especially the brain, the so-called melanoma brain metastases (MBMs). However, the precise mechanisms that sustain the growth of MBMs remain elusive. Recently, the excitatory neurotransmitter glutamate has been proposed as a brain-specific, pro-tumorigenic signal for various types of cancers, but how neuronal glutamate shuttling onto metastases is regulated remains unknown. Here, we show that the cannabinoid CB1 receptor (CB1R), a master regulator of glutamate output from nerve terminals, controls MBM proliferation. First, in silico transcriptomic analysis of cancer-genome atlases indicated an aberrant expression of glutamate receptors in human metastatic melanoma samples. Second, in vitro experiments conducted on three different melanoma cell lines showed that the selective blockade of glutamatergic NMDA receptors, but not AMPA or metabotropic receptors, reduces cell proliferation. Third, in vivo grafting of melanoma cells in the brain of mice selectively devoid of CB1Rs in glutamatergic neurons increased tumour cell proliferation in concert with NMDA receptor activation, whereas melanoma cell growth in other tissue locations was not affected. Taken together, our findings demonstrate an unprecedented regulatory role of neuronal CB1Rs in the MBM tumour microenvironment.”

https://pubmed.ncbi.nlm.nih.gov/37173906/

https://www.mdpi.com/2072-6694/15/9/2439

A Phase I Dose Escalation and Expansion Study of Epidiolex (Cannabidiol) in Patients with Biochemically Recurrent Prostate Cancer

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“Purpose: Cannabinoids (CBD) have anti-tumor activity against prostate cancer (PCa). Preclinical studies have demonstrated a significant decrease in prostate specific antigen (PSA) protein expression and reduced tumor growth in xenografts of LNCaP and DU-145 cells in athymic mice when treated with CBD. Over-the-counter CBD products may vary in activity without clear standardization, and Epidiolex is a standardized FDA-approved oral CBD solution for treatment of certain types of seizures. We aimed to assess the safety and preliminary anti-tumor activity of Epidiolex in patients with biochemically recurrent (BCR) PCa.

Experimental design: This was an open-label, single center, phase I dose escalation study followed by a dose expansion in BCR patients after primary definitive local therapy (prostatectomy +/- salvage radiotherapy or primary definitive radiotherapy). Eligible patients were screened for urine tetrahydrocannabinol prior to enrollment. The starting dose level of Epidiolex was 600 mg by mouth once daily and escalated to 800 mg daily with the use of a Bayesian optimal interval design. All patients were treated for 90 days followed by a 10-day taper. The primary endpoints were safety and tolerability. Changes in PSA, testosterone levels, and patient-reported health-related quality of life were studied as secondary endpoints.

Results: Seven patients were enrolled into the dose escalation cohort. There were no dose-limiting toxicities at the first two dose levels (600 mg and 800 mg). An additional 14 patients were enrolled at the 800 mg dose level into the dose expansion cohort. The most common adverse events were 55% diarrhea (grade 1-2), 25% nausea (grade 1-2), and 20% fatigue (grade 1-2). The mean PSA at baseline was 2.9 ng/mL. At the 12-week landmark time-point, 16 out of 18 (88%) had stable biochemical disease, one (5%) had partial biochemical response with the greatest measurable decline being 41%, and one (5%) had PSA progression. No statistically significant changes were observed in patient-reported outcomes (PROs), but PROs changed in the direction of supporting the tolerability of Epidiolex (e.g., emotional functioning improved).

Conclusion: Epidiolex at a dose of 800 mg daily appears to be safe and tolerable in patients with BCR prostate cancer supporting a safe dose for future studies.”

https://pubmed.ncbi.nlm.nih.gov/37173971/

“Cannabinoids have been widely used for pain, nausea, and appetite stimulation, and have also shown anti-tumor activity in preclinical studies of prostate cancer. Epidiolex is an oral cannabidiol solution that is FDA approved for the treatment of certain types of seizures in patients one year of age and older. We studied phase I Epidiolex dose escalation followed by dose expansion in patients with biochemically recurrent prostate cancer. A total of 21 patients were enrolled. No dose-limiting toxicities were observed at any dose level. The recommended phase 2 dose was 800 mg daily. An additional 14 patients were enrolled in the dose expansion. The most common adverse events were 55% diarrhea (grade 1–2), 25% nausea (grade 1–2), and 20% fatigue (grade 1–2). Epidiolex at a dose of 800 mg daily appears to be safe and tolerable in patients with BCR prostate cancer, supporting a safe dose for future studies.”

https://www.mdpi.com/2072-6694/15/9/2505

Antitumor mechanism of cannabidiol hidden behind cancer hallmarks

Biochimica et Biophysica Acta (BBA) - Reviews on Cancer

“Cannabinoids have been utilized for recreational and therapeutic purposes for over 4,000 years. As the primary ingredient in exogenous cannabinoids, Cannabidiol (CBD) has drawn a lot of interest from researchers due to its negligible psychotropic side effects and potential tumor-suppressing properties. However, the obscure mechanisms that underlie them remain a mystery. Complex biological mechanisms are involved in the progression of cancer, and malignancies have a variety of acquired biological capabilities, including sustained proliferation, death evasion, neovascularization, tissue invasion and metastasis, immune escape, metabolic reprogramming, induction of tumor-associated inflammation, cancerous stemness and genomic instability. Nowadays, the role of CBD hidden in these hallmarks is gradually revealed. Nevertheless, flaws or inconsistencies in the recent studies addressing the anti-cancer effects of CBD still exist. The purpose of this review is to evaluate the potential mechanisms underlying the role of CBD in a range of tumor-acquired biological capabilities. We propose potential drugs that may have a synergistic effect with CBD and provide optional directions for future research.”

https://pubmed.ncbi.nlm.nih.gov/37164234/

https://www.sciencedirect.com/science/article/abs/pii/S0304419X23000549?via%3Dihub

Therapeutic targeting of the tumor microenvironments with cannabinoids and their analogs: Update on clinical trials

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“Cancer is a major global public health concern that affects both industrialized and developing nations. Current cancer chemotherapeutic options are limited by side effects, but plant-derived alternatives and their derivatives offer the possibilities of enhanced treatment response and reduced side effects.

A plethora of recently published articles have focused on treatments based on cannabinoids and cannabinoid analogs and reported that they positively affect healthy cell growth and reverse cancer-related abnormalities by targeting aberrant tumor microenvironments (TMEs), lowering tumorigenesis, preventing metastasis, and/or boosting the effectiveness of chemotherapy and radiotherapy.

Furthermore, TME modulating systems are receiving much interest in the cancer immunotherapy field because it has been shown that TMEs have significant impacts on tumor progression, angiogenesis, invasion, migration, epithelial to mesenchymal transition, metastasis and development of drug resistance.

Here, we have reviewed the effective role of cannabinoids, their analogs and cannabinoid nano formulations on the cellular components of TME (endothelial cells, pericytes, fibroblast and immune cells) and how efficiently it retards the progression of carcinogenesis is discussed. The article summarizes the existing research on the molecular mechanisms of cannabinoids regulation of the TME and finally highlights the human studies on cannabinoids’ active interventional clinical trials.

The conclusion outlines the need for future research involving clinical trials of cannabinoids to demonstrate their efficacy and activity as a treatment/prevention for various types of human malignancies.”

https://pubmed.ncbi.nlm.nih.gov/37146933/

https://www.sciencedirect.com/science/article/abs/pii/S0013935123006540?via%3Dihub

Medical cannabis is effective for cancer-related pain: Quebec Cannabis Registry results

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“Objectives: To evaluate the safety and effectiveness of medical cannabis (MC) in reducing pain and concurrent medications in patients with cancer.

Methods: This study analysed data collected from patients with cancer who were part of the Quebec Cannabis Registry. Brief Pain Inventory (BPI), revised Edmonton Symptom Assessment System (ESAS-r) questionnaires, total medication burden (TMB) and morphine equivalent daily dose (MEDD) recorded at 3-month, 6-month, 9-month and 12-month follow-ups were compared with baseline values. Adverse events were also documented at each follow-up visit.

Results: This study included 358 patients with cancer. Thirteen out of 15 adverse events reported in 11 patients were not serious; 2 serious events (pneumonia and cardiovascular event) were considered unlikely related to MC. Statistically significant decreases were observed at 3-month, 6-month and 9-month follow-up for BPI worst pain (5.5±0.7 baseline, 3.6±0.7, 3.6±0.7, 3.6±0.8; p<0.01), average pain (4.1±0.6 baseline, 2.4±0.6, 2.3±0.6, 2.7±0.7; p<0.01), overall pain severity (3.7±0.5 baseline, 2.3±0.6, 2.3±0.6, 2.4±0.6; p<0.01) and pain interference (4.3±0.6 baseline, 2.4±0.6, 2.2±0.6, 2.4±0.7, p<0.01). ESAS-r pain scores decreased significantly at 3-month, 6-month and 9-month follow-up (3.7±0.6 baseline, 2.5±0.6, 2.2±0.6, 2.0±0.7, p<0.01). THC:CBD balanced strains were associated with better pain relief as compared with THC-dominant and CBD-dominant strains. Decreases in TMB were observed at all follow-ups. Decreases in MEDD were observed at the first three follow-ups.

Conclusions: Real-world data from this large, prospective, multicentre registry indicate that MC is a safe and effective complementary treatment for pain relief in patients with cancer. Our findings should be confirmed through randomised placebo-controlled trials.”

https://pubmed.ncbi.nlm.nih.gov/37130724/

https://spcare.bmj.com/content/early/2023/04/11/spcare-2022-004003

Repositioning Cannabinoids and Terpenes as Novel EGFR-TKIs Candidates for Targeted Therapy Against Cancer: A virtual screening model using CADD and biophysical simulations

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“This study examines the potential of Cannabis sativa L. plants to be repurposed as therapeutic agents for cancer treatment through designing of hybrid Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). A set of 50 phytochemicals was taken from Cannabinoids and Terpenes and subjected for screening using Semi-flexible and Flexible Molecular Docking methods, MM-GBSA free binding energy computations, and pharmacokinetic/pharmacodynamic (ADME-Tox) predictions.

Nine promising phytochemicals, Cannabidiolic acid (CBDA), Cannabidiol (CBD), Tetrahydrocannabivarin (THCV), Dronabinol (Δ-9-THC), Delta-8-Tetrahydrocannabinol (Δ-8-THC), Cannabicyclol (CBL), Delta9-tetrahydrocannabinolic acid (THCA), Beta-Caryophyllene (BCP), and Gamma-Elemene (γ-Ele) were identified as potential EGFR-TKIs natural product candidates for cancer therapy.

To further validate these findings, a set of Molecular Dynamics simulations were conducted over a 200 ns trajectory. This hybrid early drug discovery screening strategy has the potential to yield a new generation of EGFR-TKIs based on natural cannabis products, suitable for cancer therapy. In addition, the application of this computational strategy in the virtual screening of both natural and synthetic chemical libraries could support the discovery of a wide range of lead drug agents to address numerous diseases.”

https://pubmed.ncbi.nlm.nih.gov/37128337/

https://www.cell.com/heliyon/fulltext/S2405-8440(23)02752-4?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS2405844023027524%3Fshowall%3Dtrue

Antitumoral effects of cannabis in Notch1-mutated T-cell acute lymphoblastic leukemia

“In T-cell acute lymphoblastic leukemia (T-ALL), an aggressive hematologic cancer with poor clinical outcomes, more than 50% of cases show NOTCH1-driven transformation [1]. The NOTCH1 receptor signaling pathway is activated through a series of proteolytic cleavages, ultimately causing the release of the active intracellular domain (NICD), which translocates to the nucleus where it promotes transcription of target genes involved in cell growth. The importance of NOTCH1 mutations in T-ALL has generated great interest in the development of anti-NOTCH1 targeted therapies.

A new and promising emerging field in cancer treatment is medical cannabis. Accumulating evidence suggests the direct effects of cannabis on tumor progression in cell lines and animal models [2]. Cannabis, and its unique secondary metabolites, known as phytocannabinoids, directly affect the propagation of cancer cells by modulating key cellsignaling pathways.

We have previously demonstrated that different cannabis extracts, each containing a unique composition of metabolites, selectively impaired the survival of cancer cell lines depending on a match between the chemical composition of the extract and the characteristics of the specific cancer cell line.

In the present work, we set out to investigate whether cannabis extracts with unique phytocannabinoid profiles can selectively facilitate antitumor effects in T-ALL cells that harbor a Notch1 mutation.

In summary, targeting NOTCH1 signaling has generated much interest for its therapeutic potential. However, so far, efforts to develop such treatments have been unsuccessful.

The cannabis plant contains over 140 phytocannabinoids, many of which are presumed to have pharmacological properties, and accumulating evidence suggests anticancer capabilities.

Here, we identified a specific CBD-rich extract that selectively induced apoptosis in NOTCH1-mutated T-ALL cells. Although CBD by itself was able to induce cell death, the whole extract was more effective, suggesting that other metabolites from the plant are required to achieve full potency.

We have previously demonstrated this phenomenon in a mouse model of epilepsy, where CBD-rich extracts with equal amounts of CBD but varying concentrations of other minor compounds led to diverse anticonvulsant effects. A possible mechanism previously suggested to explain the difference between the effects of purified phytocannabinoids versus full-spectrum extracts is the “entourage effect”, where one compound may enhance the activity and efficacy of another on the same target. While this synergy is well-established for endogenous cannabinoids of the endocannabinoid system, only very few studies demonstrated this phenomenon for phytocannabinoids.

Cannabis is already being prescribed to cancer patients for its palliative qualities; however, the huge variety between different chemovars in their composition is disregarded. Matching an effective extract to certain cancer subtypes will ultimately lead to personalized cancer treatments and medications that not only treat symptoms but also treat the disease.

As dysregulation of NOTCH1 signaling has been found in various cancers other than T-ALL and in non-cancerous diseases, our findings suggest a novel therapeutic strategy for the effective treatment of a variety of malignancies.”

https://pubmed.ncbi.nlm.nih.gov/37086009/

https://onlinelibrary.wiley.com/doi/10.1002/cac2.12422

The endocannabinoid system, a new gatekeeper in the pharmacology of human hepatocellular carcinoma

Environmental Research

“Despite numerous prevention methodologies and treatment options, hepatocellular carcinoma (HCC) still remains as the third leading life-threatening cancer. It is thus pertinent to develop new treatment modality to fight this devastating carcinoma.

Ample recent studies have shown the anti-inflammatory and antitumor roles of the endocannabinoid system in various forms of cancers. Preclinical studies have also confirmed that cannabinoid therapy can be an optimal regimen for cancer treatments.

The endocannabinoid system is involved in many cancer-related processes, including induction of endoplasmic reticulum (ER) stress-dependent apoptosis, autophagy, PITRK and ERK signaling pathways, cell invasion, epithelial-mesenchymal transition (EMT), and cancer stem cell (CSC) phenotypes. Moreover, changes in signaling transduction of the endocannabinoid system can be a potential diagnostic and prognostic biomarker for HCC.

Due to its pivotal role in lipid metabolism, the endocannabinoid system affects metabolic reprogramming as well as lipid content of exosomes. In addition, due to the importance of non-coding RNAs (ncRNAs), several studies have examined the relationship between microRNAs and the endocannabinoid system in HCC. However, HCC is a pathological condition with high heterogeneity, and therefore using the endocannabinoid system for treatment has faced many controversies. While some studies favored a role of the endocannabinoid system in carcinogenesis and tumor induction, others exhibited the anticancer potential of endocannabinoids in HCC.

In this review, specific studies delineating the relationship between endocannabinoids and HCC are examined. Based on collected findings, detailed studies of the molecular mechanism of endocannabinoids as well as preclinical studies for investigating therapeutic or carcinogenic impacts in HCC cancer are strongly suggested.”

https://pubmed.ncbi.nlm.nih.gov/37062475/

https://www.sciencedirect.com/science/article/abs/pii/S0013935123007065?via%3Dihub

Cannabidiol prevents chemotherapy-induced neuropathic pain by modulating spinal TLR4 via endocannabinoid system activation

Journal of Pharmacy and Pharmacology

“Objectives: This study aimed to investigate the effect of cannabidiol (CBD) on type 4 Toll-like receptors (TLR4), glial cells and pro-inflammatory cytokines during the neuropathic pain induced by the chemotherapy agent paclitaxel (PTX), as well as the involvement of the endocannabinoid system in this process.

Methods: Male C57BL6 mice were subjected to PTX-induced neuropathic pain. To evaluate the involvement of the TLR4, glial cells and cannabinoid CB2 receptor, specific inhibitors or antagonists were intrathecally administered. The western blotting and immunofluorescence assay was performed to evaluate the spinal expression of TLR4, microglia, astrocytes and cannabinoid CB2 receptor. The levels of spinal pro-inflammatory cytokines and endocannabinoids were determined by enzyme-linked immunosorbent assay and liquid chromatography-mass spectrometry analysis, respectively.

Key findings: CBD prevented PTX-induced neuropathic pain, and the cannabinoid CB2 receptor antagonist AM630 reversed this effect. In addition, CBD treatment inhibited the spinal expression of TLR4 and Iba1 in mice with neuropathic pain. CBD also increased spinal levels of endocannabinoids anandamide and 2-arachidonoylglycerol, and reduced levels of cytokines in mice with neuropathic pain.

Conclusions: CBD was efficient in preventing PTX-induced neuropathic pain, and this effect may involve inhibition of the TLR4 on microglia spinal with activation of the endocannabinoid system.”

https://pubmed.ncbi.nlm.nih.gov/36946366/

https://academic.oup.com/jpp/advance-article-abstract/doi/10.1093/jpp/rgad023/7083482?redirectedFrom=fulltext&login=false