Category Archives: Gliomas

THC Reduces Ki67-Immunoreactive Cells Derived from Human Primary Glioblastoma in a GPR55-Dependent Manner

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cancers-logo

“Glioblastoma (GBM) is the most frequent malignant tumor of the central nervous system in humans with a median survival time of less than 15 months.

∆9-Tetrahydrocannabinol (THC) and cannabidiol (CBD) are the best-characterized components of Cannabis sativa plants with modulating effects on cannabinoid receptors 1 and 2 (CB1 and CB2) and on orphan receptors such as GPR18 or GPR55. Previous studies have demonstrated anti-tumorigenic effects of THC and CBD in several tumor entities including GBM, mostly mediated via CB1 or CB2.

In this study, we investigated the non-CB1/CB2 effects of THC on the cell cycle of GBM cells isolated from human tumor samples.

Cell cycle entry was measured after 24 h upon exposure by immunocytochemical analysis of Ki67 as proliferation marker. The Ki67-reducing effect of THC was abolished in the presence of CBD, whereas CBD alone did not cause any changes. To identify the responsible receptor for THC effects, we first characterized the cells regarding their expression of different cannabinoid receptors: CB1, CB2, GPR18, and GPR55. Secondly, the receptors were pharmacologically blocked by application of their selective antagonists AM281, AM630, O-1918, and CID16020046 (CID), respectively. All examined cells expressed the receptors, but only in presence of the GPR55 antagonist CID was the THC effect diminished. Stimulation with the GPR55 agonist lysophosphatidylinositol (LPI) revealed similar effects as obtained for THC. The LPI effects were also inhibited by CBD and CID, confirming a participation of GPR55 and suggesting its involvement in modifying the cell cycle of patient-derived GBM cells.”

https://pubmed.ncbi.nlm.nih.gov/33802282/

“Glioblastoma (GBM) is the most frequent primary brain tumor entity with poor prognosis and resistance to current standard therapies. Cannabinoids, such as tetrahydrocannabinol (THC) and cannabidiol (CBD) are discussed as promising compounds for individualized treatment, as they exert anti-tumor effects by binding to cannabinoid-specific receptors. However, their pharmacology is highly diverse and complex. The present study was designed to verify (1) whether cannabinoids show even any effect in GBM cells derived from primary human tumor samples and (2) to identify the receptor responsible for those effects. Our findings revealed that THC reduces the number of Ki67 immunoreactive nuclei, a cell cycle marker through the orphan cannabinoid receptor GPR55. The data suggest a therapeutic potential of cannabinoids in those GBM with functional and responsive GPR55.”

https://www.mdpi.com/2072-6694/13/5/1064

Efficacy of cannabinoids against glioblastoma multiforme: A systematic review

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Phytomedicine

“INTRODUCTION

: The increased incidence of Glioblastoma Multiforme, the most aggressive and most common primary brain tumour, is evident worldwide. Survival rates are reaching only 15 months due to its high recurrence and resistance to current combination therapies including oncotomy, radiotherapy and chemotherapy. Light has been shed in the recent years on the anticancer properties of cannabinoids from Cannabis sativa.

OBJECTIVE

: To determine whether cannabinoids alone or in combination with radiotherapy and/or chemotherapy inhibit tumour progression, induce cancer cell death, inhibit metastasis and invasiveness and the mechanisms that underlie these actions.

METHOD

: PubMed and Web of Science were used for a systemic search to find studies on the anticancer effects of natural cannabinoids on glioma cancer cells in vitro and/or in vivo.

RESULTS

: A total of 302 papers were identified, of which 14 studies were found to fit the inclusion criteria. 5 studies were conducted in vitro, 2 in vivo and 7 were both in vivo and in vitro. 3 studies examined the efficacy of CBD, THC and TMZ, 1 study examined CBD and radiation, 2 studies examined efficacy of THC only and 3 studies examined the efficacy of CBD only. 1 study examined the efficacy of CBD, THC and radiotherapy, 2 studies examined the combination of CBD and THC and 2 more studies examined the efficacy of CBD and TMZ.

CONCLUSION

: The evidence in this systematic review leads to the conclusion that cannabinoids possess anticancer potencies against glioma cells, however this effect varies with the combinations and dosages used. Studies so far were conducted on cells in culture and on mice as well as a small number of studies that were conducted on humans. Hence in order to have more accurate results, higher quality studies mainly including human clinical trials with larger sample sizes are necessitated urgently for GBM treatment.”

HTTPS://WWW.SCIENCEDIRECT.COM/SCIENCE/ARTICLE/ABS/PII/S0944711321000751

A cannabidiol-loaded Mg-gallate metal-organic framework-based potential therapeutic for glioblastomas

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 “Cannabidiol (CBD) has been shown to slow cancer cell growth and is toxic to human glioblastoma cell lines. Thus, CBD could be an effective therapeutic for glioblastoma.

In the present study, we explored the anticancer effect of cannabidiol loaded magnesium-gallate (CBD/Mg-GA) metal-organic framework (MOF) using the rat glioma brain cancer (C6) cell line.

Bioactive and microporous magnesium gallate MOF was employed for simultaneous delivery of two potential anticancer agents (gallic acid and CBD) to the cancer cells. Gallic acid (GA), a polyphenolic compound, is part of the MOF framework, while CBD is loaded within the framework. Slow degradation of CBD/Mg-GA MOF in physiological fluids leads to sustained release of GA and CBD.

CBD’s anti-cancer actions target mitochondria, inducing their dysfunction and generation of harmful reactive oxygen species (ROS). Anticancer effects of CBD/Mg-GA include a significant increase in ROS production and a reduction in anti-inflammatory responses as reflected by a significant decrease in TNF-α expression levels. Molecular mechanisms that underlie these effects include the modulation of NF-κB expression, triggering the apoptotic cascades of glioma cells. CBD/Mg-GA MOF has potential anti-cancer, anti-inflammatory and anti-oxidant properties.

Thus, the present study demonstrates that CBD/Mg-GA MOF may be a promising therapeutic for glioblastoma.”

https://pubmed.ncbi.nlm.nih.gov/33657198/

https://pubs.rsc.org/en/content/articlelanding/2021/TB/D0TB02780D#!divAbstract

Graphical abstract: A cannabidiol-loaded Mg-gallate metal–organic framework-based potential therapeutic for glioblastomas

Cannabidiol inhibits human glioma by induction of lethal mitophagy through activating TRPV4

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Publication Cover“Glioma is the most common primary malignant brain tumor with poor survival and limited therapeutic options. The non-psychoactive phytocannabinoid cannabidiol (CBD) has been shown to be effective against glioma; however, the molecular target and mechanism of action of CBD in glioma are poorly understood.

Here we investigated the molecular mechanisms underlying the antitumor effect of CBD in preclinical models of human glioma.

Our results showed that CBD induced autophagic rather than apoptotic cell death in glioma cells. We also showed that CBD induced mitochondrial dysfunction and lethal mitophagy arrest, leading to autophagic cell death. Mechanistically, calcium flux induced by CBD through TRPV4 (transient receptor potential cation channel subfamily V member 4) activation played a key role in mitophagy initiation. We further confirmed TRPV4 levels correlated with both tumor grade and poor survival in glioma patients. Transcriptome analysis and other results demonstrated that ER stress and the ATF4-DDIT3-TRIB3-AKT-MTOR axis downstream of TRPV4 were involved in CBD-induced mitophagy in glioma cells. Lastly, CBD and temozolomide combination therapy in patient-derived neurosphere cultures and mouse orthotopic models showed significant synergistic effect in both controlling tumor size and improving survival.

Altogether, these findings showed for the first time that the antitumor effect of CBD in glioma is caused by lethal mitophagy and identified TRPV4 as a molecular target and potential biomarker of CBD in glioma. Given the low toxicity and high tolerability of CBD, we therefore propose CBD should be tested clinically for glioma, both alone and in combination with temozolomide.”

https://pubmed.ncbi.nlm.nih.gov/33629929/

https://www.tandfonline.com/doi/abs/10.1080/15548627.2021.1885203?journalCode=kaup20

A phase 1b randomised, placebo-controlled trial of nabiximols cannabinoid oromucosal spray with temozolomide in patients with recurrent glioblastoma

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British Journal of Cancer“Preclinical data suggest some cannabinoids may exert antitumour effects against glioblastoma (GBM). Safety and preliminary efficacy of nabiximols oromucosal cannabinoid spray plus dose-intense temozolomide (DIT) was evaluated in patients with first recurrence of GBM.

Results: The most common treatment-emergent adverse events (TEAEs; both parts) were vomiting, dizziness, fatigue, nausea and headache. Most patients experienced TEAEs that were grade 2 or 3 (CTCAE). In Part 2, 33% of both nabiximols- and placebo-treated patients were progression-free at 6 months. Survival at 1 year was 83% for nabiximols- and 44% for placebo-treated patients (p = 0.042), although two patients died within the first 40 days of enrolment in the placebo arm. There were no apparent effects of nabiximols on TMZ PK.

Conclusions: With personalised dosing, nabiximols had acceptable safety and tolerability with no drug-drug interaction identified. The observed survival differences support further exploration in an adequately powered randomised controlled trial.”

https://pubmed.ncbi.nlm.nih.gov/33623076/

https://www.nature.com/articles/s41416-021-01259-3

Synthetic Cannabinoids Induce Autophagy and Mitochondrial Apoptotic Pathways in Human Glioblastoma Cells Independently of Deficiency in TP53 or PTEN Tumor Suppressors

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cancers-logo“Glioblastomas (GBMs) are aggressive brain tumors with frequent genetic alterations in TP53 and PTEN tumor suppressor genes rendering resistance to standard chemotherapeutics. Cannabinoid type 1 and 2 (CB1/CB2) receptor expression in GBMs and antitumor activity of cannabinoids in glioma cells and animal models, raised promises for a targeted treatment of these tumors. The susceptibility of human glioma cells to CB2-agonists and their mechanism of action are not fully elucidated. We determined CB1 and CB2 expression in 14 low-grade and 21 high-grade tumor biopsies, GBM-derived primary cultures and established cell lines. The non-selective CB receptor agonist WIN55,212-2 (but not its inactive enantiomer) or the CB2-selective agonist JWH133 induced apoptosis in patient-derived glioma cultures and five established glioma cell lines despite p53 and/or PTEN deficiency. Growth inhibitory efficacy of cannabinoids correlated with CB1/CB2 expression (EC50 WIN55,212-2: 7.36-15.70 µM, JWH133: 12.15-143.20 µM). Treatment with WIN55,212-2 or JWH133 led to activation of the apoptotic mitochondrial pathway and DNA fragmentation. Synthetic cannabinoid action was associated with the induction of autophagy and knockdown of autophagy genes augmented cannabinoid-induced apoptotic cell death. The high susceptibility of human glioblastoma cells to synthetic cannabinoids, despite genetic defects contributing to apoptosis resistance, makes cannabinoids promising anti-glioma therapeutics.”

https://pubmed.ncbi.nlm.nih.gov/33499365/

“Glioblastomas (GBMs) are aggressive brain tumors with frequent genetic defects in TP53 and PTEN tumor suppressor genes, which render tumors refractory to standard chemotherapeutics.

Natural and synthetic cannabinoids showed antitumor activity in glioma cells and animal glioma models.

Due to differences in the expression of cannabinoid type 2 receptors (CB2), which are abundant in GBMs but absent from a healthy brain, we tested synthetic cannabinoids for their ability to kill numerous glioma cells. We performed multiple biochemical analyses to determine which cell death pathways are activated in human glioma cells. We demonstrate high susceptibility of human glioblastoma cells to synthetic cannabinoids, despite genetic defects contributing to apoptosis resistance, which makes cannabinoids promising anti-glioma therapeutics.”

https://www.mdpi.com/2072-6694/13/3/419

Cannabigerol Is a Potential Therapeutic Agent in a Novel Combined Therapy for Glioblastoma

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cells-logo“Glioblastoma is the most aggressive cancer among primary brain tumours. As with other cancers, the incidence of glioblastoma is increasing; despite modern therapies, the overall mean survival of patients post-diagnosis averages around 16 months, a figure that has not changed in many years. Cannabigerol (CBG) has only recently been reported to prevent the progression of certain carcinomas and has not yet been studied in glioblastoma. Here, we have compared the cytotoxic, apoptotic, and anti-invasive effects of the purified natural cannabinoid CBG together with CBD and THC on established differentiated glioblastoma tumour cells and glioblastoma stem cells. CBG and THC reduced the viability of both types of cells to a similar extent, whereas combining CBD with CBG was more efficient than with THC. CBD and CBG, both alone and in combination, induced caspase-dependent cell apoptosis, and there was no additive THC effect. Of note, CBG inhibited glioblastoma invasion in a similar manner to CBD and the chemotherapeutic temozolomide. We have demonstrated that THC has little added value in combined-cannabinoid glioblastoma treatment, suggesting that this psychotropic cannabinoid should be replaced with CBG in future clinical studies of glioblastoma therapy.”

https://pubmed.ncbi.nlm.nih.gov/33562819/

“Among primary brain tumours, glioblastoma is the most aggressive. As early relapses are unavoidable despite standard-of-care treatment, the cannabinoids delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) alone or in combination have been suggested as a combined treatment strategy for glioblastomas. However, the known psychoactive effects of THC hamper its medical applications in these patients with potential cognitive impairment due to the progression of the disease. Therefore, nontoxic cannabigerol (CBG), being recently shown to exhibit anti-tumour properties in some carcinomas, is assayed here for the first time in glioblastoma with the aim to replace THC. We indeed found CBG to effectively impair the relevant hallmarks of glioblastoma progression, with comparable killing effects to THC and in addition inhibiting the invasion of glioblastoma cells. Moreover, CBG can destroy therapy-resistant glioblastoma stem cells, which are the root of cancer development and extremely resistant to various other treatments of this lethal cancer. CBG should present a new yet unexplored adjuvant treatment strategy of glioblastoma.”

https://www.mdpi.com/2073-4409/10/2/340

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

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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

Education and communication are critical to effectively incorporating cannabis into cancer treatment

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“Providers need to be better equipped to discuss medical cannabis with patients even if they are not willing to prescribe it. The oncology community would be well served to ensure that providers are aware of existing cannabis research and are able to incorporate it into their communications with patients instead of leaving patients to figure out medical cannabis on their own.”

https://pubmed.ncbi.nlm.nih.gov/32986251/

https://acsjournals.onlinelibrary.wiley.com/doi/10.1002/cncr.33204

Cancer patients’ experiences with medicinal cannabis-related care

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 “Background: Little is known about medical cannabis (MC)-related care for patients with cancer using MC.

Methods: Semistructured telephone interviews were conducted in a convenience sample of individuals (n = 24) with physician-confirmed oncologic diagnoses and state/district authorization to use MC (Arizona, California, Florida, Illinois, Massachusetts, Oregon, New York, and Washington, DC) from April 2017 to March 2019. Standard qualitative techniques were used to assess the degree of MC-related health care oversight, MC practices, and key information sources.

Results: Among 24 participants (median age, 57 years; range, 30-71 years; 16 women [67%]), MC certifications were typically issued by a professional new to a patient’s care after a brief, perfunctory consultation. Patients disclosed MCuse to their established medical teams but received little medical advice about whether and how to use MC. Patients with cancer used MC products as multipurpose symptom management and as cancer-directed therapy, sometimes in lieu of standard-of-care treatments. Personal experimentation, including methodical self-monitoring, was an important source of MC know-how. Absent formal advice from medical professionals, patients relied on nonmedical sources for MC information.

Conclusions: Patients with cancer used MC with minimal medical oversight. Most received MC certifications through brief meetings with unfamiliar professionals. Participants desired but were often unable to access high-quality clinical information about MC from their established medical teams. Because many patients are committed to using MC, a product sustained by a growing industry, medical providers should familiarize themselves with the existing data for MM and its limitations to address a poorly met clinical need.”

https://pubmed.ncbi.nlm.nih.gov/32986266/

“Notably, oncology patients reported using medical cannabis (MC) for symptom management and as cancer‐directed therapy, sometimes instead of traditional treatments.”

https://acsjournals.onlinelibrary.wiley.com/doi/10.1002/cncr.33202