From bench to bedside: the application of cannabidiol in glioma

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“Glioma is the most common malignant tumor in central nervous system, with significant health burdens to patients. Due to the intrinsic characteristics of glioma and the lack of breakthroughs in treatment modalities, the prognosis for most patients remains poor. This results in a heavy psychological and financial load worldwide.

In recent years, cannabidiol (CBD) has garnered widespread attention and research due to its anti-tumoral, anti-inflammatory, and neuroprotective properties.

This review comprehensively summarizes the preclinical and clinical research on the use of CBD in glioma therapy, as well as the current status of nanomedicine formulations of CBD, and discusses the potential and challenges of CBD in glioma therapy in the future.”

“CBD, a non-psychoactive cannabinoid derived from the cannabis plant, has shown promising potential in the treatment of gliomas. Characterized by its safety, good tolerability, and absence of psychoactive effects, CBD induces apoptosis in glioma cells, mitochondrial dysfunction, and autophagy, thereby inhibiting the proliferation and invasion of glioma cells, suppressing the expression of GSCs properties, and promoting cell death. Additionally, it enhances the sensitivity to radiotherapy and chemotherapy while protecting neural functions, playing a significant role in the management of glioma symptoms. Preclinical and clinical studies have demonstrated encouraging anti-glioma activity. “

The antitumor action of endocannabinoids in the tumor microenvironment of glioblastoma

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“Approximately 80% of all malignant brain tumors are gliomas, which are primary brain tumors. The most prevalent subtype of glioma, glioblastoma multiforme (GBM), is also the most deadly. Chemotherapy, immunotherapy, surgery, and conventional pharmacotherapy are currently available therapeutic options for GBM; unfortunately, these approaches only prolong the patient’s life by 5 years at most. Despite numerous intensive therapeutic options, GBM is considered incurable.

Accumulating preclinical data indicate that overt antitumoral effects can be induced by pharmacologically activating endocannabinoid receptors on glioma cells by modifying important intracellular signaling cascades. The complex mechanism underlying the endocannabinoid receptor-evoked antitumoral activity in experimental models of glioma may inhibit the ability of cancer cells to invade, proliferate, and exhibit stem cell-like characteristics, along with altering other aspects of the complex tumor microenvironment. The exact biological function of the endocannabinoid system in the development and spread of gliomas, however, is remains unclear and appears to rely heavily on context.

Previous studies have revealed that endocannabinoid receptors are present in the tumor microenvironment, suggesting that these receptors could be novel targets for the treatment of GBM. Additionally, endocannabinoids have demonstrated anticancer effects through signaling pathways linked to the classic features of cancer. Thus, the pharmacology of endocannabinoids in the glioblastoma microenvironment is the main topic of this review, which may promote the development of future GBM therapies.”

Altering biomolecular condensates as a potential mechanism that mediates cannabidiol effect on glioblastoma

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“Glioblastoma (GBM) is an extremely aggressive primary brain tumor with poor prognosis, short survival time post-diagnosis and high recurrence. Currently, no cure for GBM exists. The identification of an effective therapeutic modality for GBM remains a high priority amongst medical professionals and researches.

In recent studies, inhalant cannabidiol (CBD) has demonstrated promise in effectively inhibiting GBM tumor growth.

However, exactly how CBD treatment affects the physiology of these tumor cells remains unclear. Stress granules (SG) (a sub-class of biomolecular condensates (BMC)) are dynamic, membrane-less intracellular microstructures which contain proteins and nucleic acids. The formation and signaling of SGs and BMCs plays a significant role in regulating malignancies.

This study investigates whether inhaled CBD may play an intervening role towards SGs in GBM tumor cells. Integrated bioinformatics approaches were preformed to gain further insights. This includes use of Immunohistochemistry and flow cytometry to measure SGs, as well as expression and phosphorylation of eukaryotic initiation factor-2α (eIF2α).

The findings of this study reveal that CBD receptors (and co-regulated genes) have the potential to play an important biological role in the formation of BMCs within GBM. In this experiment, CBD treatment significantly increased the volume of TIAR-1. This increase directly correlated with elevation in both eIF2α expression and p-eIF2α in CBD treated tissues in comparison to the placebo group (p < 0.05).

These results suggest that inhalant CBD significantly up-regulated SGs in GBM, and thus support a theory of targeting BMCs as a potential therapeutic substrate for treating GBM.”

Cannabidiol induces ERK activation and ROS production to promote autophagy and ferroptosis in glioblastoma cells

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“Small molecule-driven ERK activation is known to induce autophagy and ferroptosis in cancer cells. Herein the effect of cannabidiol (CBD), a phytochemical derived from Cannabis sativa, on ERK-driven autophagy and ferroptosis has been demonstrated in glioblastoma (GBM) cells (U87 and U373 cells).

CBD imparted significant cytotoxicity in GBM cells, induced activation of ERK (not JNK and p38), and increased intracellular reactive oxygen species (ROS) levels. It increased the autophagy-related proteins such as LC3 II, Atg7, and Beclin-1 and modulated the expression of ferroptosis-related proteins such as glutathione peroxidase 4 (GPX4), SLC7A11, and TFRC. CBD significantly elevated the endoplasmic reticulum stress, ROS, and iron load, and decreased GSH levels. Inhibitors of autophagy (3-MA) and ferroptosis (Fer-1) had a marginal effect on CBD-induced autophagy/ferroptosis. Treatment with N-acetyl-cysteine (antioxidant) or PD98059 (ERK inhibitor) partly reverted the CBD-induced autophagy/ferroptosis by decreasing the activation of ERK and the production of ROS.

Overall, CBD induced autophagy and ferroptosis through the activation of ERK and generation of ROS in GBM cells.”

“In this study, we investigated the anti-cancer effect of CBD. CBD activated ROS production and ERK pathway and modulated the expression of proteins related to autophagy and ferroptosis. Additionally, CBD suppressed the activity of SLC7A11, a component of the System Xc-cystine/glutamate receptor, and enhanced the expression of TFRC, an iron ion channel. Through these mechanisms, our study provides evidence that CBD stimulates both autophagy and ferroptosis in GBM cells”

Cannabinoids in the treatment of glioblastoma

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“Glioblastoma (GBM) is the most prevalent primary malignant tumor of the nervous system. While the treatment of other neoplasms is increasingly more efficacious the median survival rate of GBM patients remains low and equals about 14 months. Due to this fact, there are intensive efforts to find drugs that would help combat GBM.

Nowadays cannabinoids are becoming more and more important in the field of cancer and not only because of their properties of antiemetic drugs during chemotherapy. These compounds may have a direct cytotoxic effect on cancer cells.

Studies indicate GBM has disturbances in the endocannabinoid system-changes in cannabinoid metabolism as well as in the cannabinoid receptor expression. The GBM cells show expression of cannabinoid receptors 1 and 2 (CB1R and CB2R), which mediate various actions of cannabinoids. Through these receptors, cannabinoids inhibit the proliferation and invasion of GBM cells, along with changing their morphology.

Cannabinoids also induce an intrinsic pathway of apoptosis in the tumor. Hence the use of cannabinoids in the treatment of GBM may be beneficial to the patients. So far, studies focusing on using cannabinoids in GBM therapy are mainly preclinical and involve cell lines and mice.

The results are promising and show cannabinoids inhibit GBM growth. Several clinical studies are also being carried out.

The preliminary results show good tolerance of cannabinoids and prolonged survival after administration of these drugs.

In this review, we describe the impact of cannabinoids on GBM and glioma cells in vitro and in animal studies. We also provide overview of clinical trials on using cannabinoids in the treatment of GBM.”

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.”