Targeting the Endocannabinoid System Present in the Glioblastoma Tumour Microenvironment as a Potential Anti-Cancer Strategy

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“The highly aggressive and invasive glioblastoma (GBM) tumour is the most malignant lesion among adult-type diffuse gliomas, representing the most common primary brain tumour in the neuro-oncology practice of adults. With a poor overall prognosis and strong resistance to treatment, this nervous system tumour requires new innovative treatment. GBM is a polymorphic tumour consisting of an array of stromal cells and various malignant cells contributing to tumour initiation, progression, and treatment response.

Cannabinoids possess anti-cancer potencies against glioma cell lines and in animal models.

To improve existing treatment, cannabinoids as functionalised ligands on nanocarriers were investigated as potential anti-cancer agents. The GBM tumour microenvironment is a multifaceted system consisting of resident or recruited immune cells, extracellular matrix components, tissue-resident cells, and soluble factors. The immune microenvironment accounts for a substantial volume of GBM tumours. The barriers to the treatment of glioblastoma with cannabinoids, such as crossing the blood-brain barrier and psychoactive and off-target side effects, can be alleviated with the use of nanocarrier drug delivery systems and functionalised ligands for improved specificity and targeting of pharmacological receptors and anti-cancer signalling pathways.

This review has shown the presence of endocannabinoid receptors in the tumour microenvironment, which can be used as a potential unique target for specific drug delivery. Existing cannabinoid agents, studied previously, show anti-cancer potencies via signalling pathways associated with the hallmarks of cancer. The results of the review can be used to provide guidance in the design of future drug therapy for glioblastoma tumours.”

“Cannabinoids may offer a more effective and tolerable treatment option for GBM patients.”

A randomised phase II trial of temozolomide with or without cannabinoids in patients with recurrent glioblastoma (ARISTOCRAT): protocol for a multi-centre, double-blind, placebo-controlled trial

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“Background: Glioblastoma (GBM) is the most common adult malignant brain tumour, with an incidence of 5 per 100,000 per year in England. Patients with tumours showing O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation represent around 40% of newly diagnosed GBM. Relapse/tumour recurrence is inevitable. There is no agreed standard treatment for patients with GBM, therefore, it is aimed at delaying further tumour progression and maintaining health-related quality of life (HRQoL). Limited clinical trial data exist using cannabinoids in combination with temozolomide (TMZ) in this setting, but early phase data demonstrate prolonged overall survival compared to TMZ alone, with few additional side effects.

Jazz Pharmaceuticals (previously GW Pharma Ltd.) have developed nabiximols (trade name Sativex®), an oromucosal spray containing a blend of cannabis plant extracts, that we aim to assess for preliminary efficacy in patients with recurrent GBM.

Methods: ARISTOCRAT is a phase II, multi-centre, double-blind, placebo-controlled, randomised trial to assess cannabinoids in patients with recurrent MGMT methylated GBM who are suitable for treatment with TMZ. Patients who have relapsed ≥ 3 months after completion of initial first-line treatment will be randomised 2:1 to receive either nabiximols or placebo in combination with TMZ. The primary outcome is overall survival time defined as the time in whole days from the date of randomisation to the date of death from any cause. Secondary outcomes include overall survival at 12 months, progression-free survival time, HRQoL (using patient reported outcomes from QLQ-C30, QLQ-BN20 and EQ-5D-5L questionnaires), and adverse events.

Discussion: Patients with recurrent MGMT promoter methylated GBM represent a relatively good prognosis sub-group of patients with GBM. However, their median survival remains poor and, therefore, more effective treatments are needed. The phase II design of this trial was chosen, rather than phase III, due to the lack of data currently available on cannabinoid efficacy in this setting. A randomised, double-blind, placebo-controlled trial will ensure an unbiased robust evaluation of the treatment and will allow potential expansion of recruitment into a phase III trial should the emerging phase II results warrant this development.”

“Phytocannabinoids occur naturally in cannabis plants and have been used medicinally for centuries for a variety of purposes . Δ9-tetrahydrocannabinol (THC) is the major psychoactive constituent in cannabis, and cannabidiol (CBD) the major non-psychoactive constituent.

In vivo studies have found that the administration of CBD and THC reduced tumour growth in animal models of glioma.

Jazz Pharmaceuticals (previously GW Pharma Ltd.) have developed nabiximols (trade name Sativex®), an oromucosal spray of a complex botanical mixture containing THC and CBD as the principal cannabinoids, with additional cannabinoid constituents and non-cannabinoid components.”

“Sativex is a standardized medication containing 2.5 mg/actuation CBD and 2.7 mg/ actuation THC.”

Elucidation of GPR55-Associated Signaling behind THC and LPI Reducing Effects on Ki67-Immunoreactive Nuclei in Patient-Derived Glioblastoma Cells

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“GPR55 is involved in many physiological and pathological processes. In cancer, GPR55 has been described to show accelerating and decelerating effects in tumor progression resulting from distinct intracellular signaling pathways. GPR55 becomes activated by LPI and various plant-derived, endogenous, and synthetic cannabinoids.

Cannabinoids such as THC exerted antitumor effects by inhibiting tumor cell proliferation or inducing apoptosis.

Besides its effects through CB1 and CB2 receptors, THC modulates cellular responses among others via GPR55. Previously, we reported a reduction in Ki67-immunoreactive nuclei of human glioblastoma cells after GPR55 activation in general by THC and in particular by LPI. In the present study, we investigated intracellular mechanisms leading to an altered number of Ki67+ nuclei after stimulation of GPR55 by LPI and THC. Pharmacological analyses revealed a strongly involved PLC-IP3 signaling and cell-type-specific differences in Gα-, Gβγ-, RhoA-ROCK, and calcineurin signaling. Furthermore, immunochemical visualization of the calcineurin-dependent transcription factor NFAT revealed an unchanged subcellular localization after THC or LPI treatment. The data underline the cell-type-specific diversity of GPR55-associated signaling pathways in coupling to intracellular G proteins. Furthermore, this diversity might determine the outcome and the individual responsiveness of tumor cells to GPR55 stimulation by cannabinoids.”

Synergistic inhibition of glioblastoma multiforme through an in-silico analysis of luteolin and ferulic acid derived from Angelica sinensis and Cannabis sativa: Advancements in computational therapeutics

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“The primary objective of this study is to uncover novel therapeutic agents for the treatment of Glioblastoma Multiforme (GBM), a highly aggressive form of brain cancer, and Alzheimer’s Disease (AD). Given the complexity and resistance associated with both conditions, the study underscores the imperative need for therapeutic alternatives that can traverse the biological intricacies inherent in both neuro-oncological and neurodegenerative disorders. To achieve this, a meticulous, target-based virtual screening was employed on an ensemble of 50 flavonoids and polyphenol derivatives primarily derived from plant sources. The screening focused predominantly on molecular targets pertinent to GBM but also evaluated the potential overlap with neural pathways involved in AD. The study utilized molecular docking and Molecular Dynamic (MD) simulation techniques to analyze the interaction of these compounds with a key biological target, protein tyrosine phosphatase receptor-type Z (PTPRZ). Out of the 50 compounds examined, 10 met our stringent criteria for binding affinity and specificity. Subsequently, the highest value of binding energy was observed for the synergistic binding of luteolin and ferulic acid with the value of -10.5 kcal/mol. Both compounds exhibited inherent neuroprotective properties and demonstrated significant potential as pathway inhibitors in GBM as well as molecular modulators in AD. Drawing upon advanced in-silico cytotoxicity predictions and sophisticated molecular modeling techniques, this study casts a spotlight on the therapeutic capabilities of polyphenols against GBM. Furthermore, our findings suggest that leveraging these compounds could catalyze a much-needed paradigm shift towards more integrative therapeutic approaches that span the breadth of both neuro-oncology and neurodegenerative diseases. The identification of cross-therapeutic potential in flavonoids and polyphenols could drastically broaden the scope of treatment modalities against both fatal diseases.”

Cannabinol inhibits cell growth and triggers cell cycle arrest and apoptosis in cancer cells

Biocatalysis and Agricultural Biotechnology

“Cancer is one of the most difficult diseases to treat and cure.”

“Cannabinol (CBN), one of the active ingredients from the cannabis plant, is the breakdown molecule of Δ9-tetrahydrocannabinol (Δ9-THC) which is the most abundant psychoactive cannabinoid.”

“Cannabinol (CBN) is a weak-psychoactive cannabinoid and has been shown to exert several bio-logical activities. At the same time, not much is known about the anti-cancer activities of CBN. In this report, we characterized the anti-tumor effects of CBN on the glioma A172, liver cancer HepG2 and breast cancer HCC1806 cell lines.

We found that CBN reduces the proliferation of the analyzed cancer cells and modulates the level of cannabinoid receptors, including GPR18, CB2 and GPR55. Furthermore, CBN inhibits the ERK1/2 pathway in A172 and HepG2 cells, while suppressing the AKT pathway in HCC1086 cells. Moreover, CBN may cause apoptosis through downregulation of p21 and p27 as well as a cell cycle arrest at G1 or S-phase via decreasing the CDK1, CDK2, and cyclin E1 levels.

Taken together, these results offer new insights into the anti-cancer properties of CBN.”

“CBN, one of the weak-psychoactive cannabinoids, have demonstrated various medicinal properties, including anti-inflammatory, antibacterial, analgesic and even anti-tumor.”

“In this study, we revealed the antitumor activity of CBN in three different tumor cell lines, glioma A172, liver cancer HepG2 and breast cancer HCC1806 cell lines. We report that cannabinol inhibits proliferation of several cancer cell lines by regulation of the signaling pathways involving ERK and AKT as well as by altering the expression of cannabinoid receptors. Moreover, we also found that CBN induces apoptosis and cell cycle arrest and partially uncovered underlying molecular mechanisms. Our findings provide novel information about the anti-cancer properties of CBN and justify further research to investigate the role of CBN as cancer therapeutic.”

Mechanisms Involved in the Therapeutic Effect of Cannabinoid Compounds on Gliomas: A Review with Experimental Approach

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“Introduction: Brain tumors have high morbidity and mortality rates, accounting for 1.4% of all cancers. Gliomas are the most common primary brain tumors in adults. Currently, several thera-peutic approaches are used; however, they are associated with side effects that affect pa-tients’quality of life. Therefore, further studies are needed to develop novel therapeutic protocols with a more favorable side effect profile. In this context, cannabinoid compounds may serve as potential alternatives.

Objective: This study aimed to review the key enzymatic targets involved in glioma pathophysi-ology and evaluate the potential interaction of these targets with four cannabinoid derivatives through molecular docking simulations.

Methods: Molecular docking simulations were performed using four cannabinoid compounds and six molecular targets associated with glioma pathophysiology.

Results: Encouraging interactions between the selected enzymes and glioma-related targets were observed, suggesting their potential activity through these pathways. In particular, cannabigerol showed promising interactions with epidermal growth factor receptors and phosphatidylinositol 3-kinase, while Δ-9-tetrahydrocannabinol showed remarkable interactions with telomerase reverse transcriptase.

Conclusion: The evaluated compounds exhibited favorable interactions with the analyzed enzy-matic targets, thus representing potential candidates for further in vitro and in vivo studies.”

Etoricoxib-Cannabidiol Combo: Potential Role in Glioblastoma Treatment and Development of PLGA-Based Nanoparticles

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“Background: Glioblastoma (GBM) is the most frequently occurring primary malignant central nervous system tumor, with a poor prognosis and median survival below two years. Administration of a combination of non-steroidal anti-inflammatory drugs and natural compounds that exhibit a curative or prophylactic effect in cancer is a new approach to GBM treatment. This study aimed to investigate the synergistic antitumor activity of etoricoxib (ETO) and cannabidiol (CBD) in a GBM cell line model, and to develop poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles (NPs) for these two substances.

Methods: The activity of ETO+CBD was determined using the MTT test, cell-cycle distribution assay, and apoptosis analysis using two GBM cell lines, namely, T98G and U-138 MG. The PLGA-based NPs were developed using the emulsification and solvent evaporation method. Their physicochemical properties, such as shape, size, entrapment efficiency (EE%), in vitro drug release, and quality attributes, were determined using scanning electron microscopy, diffraction light scattering, high-performance liquid chromatography, infrared spectroscopy, and differential scanning calorimetry.

Results: The combination of ETO and CBD reduced the viability of cells in a dose-dependent manner and induced apoptosis in both tested GBM cell lines. The developed method allowed for the preparation of ETO+CBD-NPs with a spherical shape, mean particle size (MPS) below 400 nm, zeta potential (ZP) values from -11 to -17.4 mV, polydispersity index (PDI) values in the range from 0.029 to 0.256, and sufficient EE% of both drugs (78.43% for CBD, 10.94% for ETO).

Conclusions: The combination of ETO and CBD is a promising adjuvant therapeutic in the treatment of GBM, and the prepared ETO+CBD-NPs exhibit a high potential for further pharmaceutical formulation development.”

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.”

Endocannabinoids are potential inhibitors of glioblastoma multiforme proliferation

Journal of Integrative Medicine

“Globally, it is evident that glioblastoma multiforme (GBM) is an aggressive malignant cancer with a high mortality rate and no effective treatment options. Glioblastoma is classified as the stage-four progression of a glioma tumor, and its diagnosis results in a shortened life expectancy. Treatment options for GBM include chemotherapy, immunotherapy, surgical intervention, and conventional pharmacotherapy; however, at best, they extend the patient’s life by a maximum of 5 years. GBMs are considered incurable due to their high recurrence rate, despite various aggressive therapeutic approaches which can have many serious adverse effects.

Ceramides, classified as endocannabinoids, offer a promising novel therapeutic approach for GBM. Endocannabinoids may enhance the apoptosis of GBM cells but have no effect on normal healthy neural cells. Cannabinoids promote atypical protein kinase C, deactivate fatty acid amide hydrolase enzymes, and activate transient receptor potential vanilloid 1 (TRPV1) and TRPV2 to induce pro-apoptotic signaling pathways without increasing endogenous cannabinoids. In previous in vivo studies, endocannabinoids, chemically classified as amide formations of oleic and palmitic acids, have been shown to increase the pro-apoptotic activity of human cancer cells and inhibit cell migration and angiogenesis.

This review focuses on the biological synthesis and pharmacology of endogenous cannabinoids for the enhancement of cancer cell apoptosis, which have potential as a novel therapy for GBM.”

“As discussed above, endocannabinoids could prove to be a viable alternative treatment for GBM.”

Therapeutic and Supportive Effects of Cannabinoids in Patients with Brain Tumors (CBD Oil and Cannabis)


“The potential medicinal properties of Cannabis continue to garner attention, especially in the brain tumor domain. This attention is centered on quality of life and symptom management; however, it is amplified by a significant lack of therapeutic choices for this specific patient population.

While the literature on this matter is young, published and anecdotal evidence imply that cannabis could be useful in treating chemotherapy-induced nausea and vomiting, stimulating appetite, reducing pain, and managing seizures. It may also decrease inflammation and cancer cell proliferation and survival, resulting in a benefit in overall patient survival.

Current literature poses the challenge that it does not provide standardized guidance on dosing for the above potential indications and cannabis use is dominated by recreational purposes. Furthermore, integrated and longitudinal studies are needed but these are a challenge due to arcane laws surrounding the legality of such substances. The increasing need for evidence-based arguments about potential harms and benefits of cannabis, not only in cancer patients but for other medical use and recreational purposes, is desperately needed.”