Antitumor Potential of Antiepileptic Drugs in Human Glioblastoma: Pharmacological Targets and Clinical Benefits

Use of psychotropic medications among glioma patients in Denmark, Norway, Sweden, and Wales

PURPOSE

Glioma patients often suffer from psychiatric and neurological conditions. However, little is known about the patterns of use of psychotropic drugs pre- and post-glioma diagnosis. Therefore, we assessed temporal patterns of psychotropic prescriptions among glioma patients, compared to an age and sex matched comparison cohort in four European countries.

METHODS

Incident gliomas were identified in Wales from the Secured Anonymized Information Linkage Databank (2005-2016) and population-based registries in Denmark (2001-2016), Norway (2006-2019), and Sweden (2008-2018). From each data source, a cancer-free comparison cohort was matched to the glioma cases by age and sex. We calculated rates of new psychotropic prescriptions and any psychotropic prescriptions during the 2 years prior to and post glioma diagnosis. Analyses were stratified by histological subtypes and subclasses of psychotropic medications.

RESULTS

We identified 16,007 glioma patients. The rate of new psychotropic drug use increased from 7 months before diagnosis, peaking around the month of glioma diagnosis (with peak rates ranging from 227 to 753 new psychotropic drugs per 1000 person-months). New use remained substantially higher among glioma patients than comparators throughout the 2-year follow-up period after glioma diagnosis, though rates of new use continued to decline throughout. New use was largely driven by antiepileptics, anxiolytics, hypnotics, and sedatives. Patterns were similar when analyses were stratified by histological subtype.

CONCLUSION

Psychotropic drug use among glioma patients was high, and elevations observed around the time of cancer diagnosis, largely driven by antiepileptics, anxiolytics, hypnotics, and sedatives, are likely associated with the consequences of the disease.

Characteristics, outcome, and prognostic factors of young patients with central nervous system World Health Organization grade 3 oligodendrogliomas IDH-mutant and 1p/19q codeleted: A French POLA network study

BACKGROUND

Brain tumors represent one of the main causes of cancer-related mortality in young patients. Among them, oligodendrogliomas (OG) are adult-type diffuse gliomas with the best prognosis. Nevertheless, characterization of these tumors in the young population remains poorly documented. Our objective was to characterize the population of young adults under 40 years of age with grade 3 OG in the POLA cohort.

METHODS

Clinical data prospectively collected for all patients registered with grade 3 OG between April 2009 and August 2021 were extracted from the national POLA database. This study compared the patient subgroup <40 years of age to the one >40 years of age.

RESULTS

The authors included 111 patients <40 years old and 363 patients ≥40 years old. Treatment received did not differ significantly between the two subgroups. Temporal location was more frequent in older patients (p = .009). Patients <40 years old presented more often seizure as initial symptom (p = .003). They had less frequent chromosome 9p loss (p < .001) and less CDKN2A homozygous deletion (p = .024). Median progression-free survival (PFS) was 123 months (range, 86-not reached [NR]) versus 88 months (range, 67-117) (p = .082) and median overall survival (OS) was not reached (range, 147-NR) versus 163 months (range, 137-NR) (p < .001) in younger and older subgroups, respectively. In multivariate analysis, complete or subtotal resection (p = .014) and seizure at diagnosis (p = .032) were associated with better OS.

CONCLUSION

Young patients with grade 3 OG have distinct clinical presentation, molecular features, and outcomes compared to the older patients.

Incomplete Decarboxylation of Acidic Cannabinoids in GC-MS Leads to Underestimation of the Total Cannabinoid Content in Cannabis Oils Without Derivatization

Background: Cannabis oil titration consists of quantification of the acidic precursors tetrahydrocannabinolic acid (THCA) and cannabidiolic acid (CBDA) and their decarboxylated products, the active neutral cannabinoids delta-9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD), and is recommended to ensure galenic preparation quality through gas and liquid chromatography coupled with mass spectrometry (GC-MS; LC-MS). Analyses by LC-MS and GC-MS involving derivatization allow for detection of acidic and neutral cannabinoids; on the contrary, GC-MS without derivatization determines only neutral cannabinoids due to high temperature-decarboxylation occurring in the injection system. However, it is not clear if decarboxylation is complete. Methods: Different GC-MS methods with (BSTFA: TMCS and pyridine; incubation at 60 °C for 25 min) or without derivatization and an LC-MS method were developed for cannabinoid quantification. The total Δ9-THC and CBD yield of recovery were compared between the methods by testing laboratory samples with known concentrations of THCA and CBDA (total Δ9-THC and CBD: 175-351-702 ng/mL) and real cannabis oil samples (n = 6). Results: The total Δ9-THC and CBD yield of recovery were determined using LC-MS and GC-MS with derivatization, but not using GC-MS without derivatization (decarboxylation conversion rate of about 50-60%). No high deviation (<10%) in the total neutral cannabinoid concentrations in real cannabis oil samples was noticed, probably due to the low content of acidic forms in the original galenic preparation. Conclusions: This study raised awareness about the potential underestimation of the total Δ9-THC and CBD content in cannabis oils when quantification is performed by GC-MS without derivatization. The advice for pharmacists is to perform complete decarboxylation to convert all acidic precursors in neutral cannabinoids.

Growth of the prefrontal cortical glioblastoma altered cognitive and emotional behaviors via mediating miRNAs and GABA-A receptor signaling pathways in rats

The present study investigated the impact of GABAergic signaling and miRNA expression on glioblastoma multiforme (GBM) growth within the medial prefrontal cortex (mPFC) and its associated cognitive and emotional impairments. The implantation of C6 cells into the mPFC induced GBM in this brain region (referred to as the mPFC-GBM) in male Wistar rats via stereotaxic surgery, as confirmed by Magnetic Resonance Imaging (MRI), and Hematoxylin and Eosin (H&E) staining. Repeated microinjections of muscimol, a potent GABAA receptor agonist, directly into the mPFC-GBM (1 µg/rat/2.5 μl) following tumor induction decreased tumor volume and weight, resulting in an increased survival rate. Conversely, a higher dose of muscimol (6 µg/rat/2.5 μl) increased tumor size and reduced survival. Behavioral alterations induced by GBM, including anxiety-like responses, exploratory behaviors, locomotor activity, and memory formation, were assessed using anxiety-like behavior task, the hole-board test, and the novel object recognition test. Muscimol treatment dose-dependently affected these behaviors in the animals with the mPFC-GBM, bringing their performance with that of the sham group at the dose of 1 µg/rat/2.5 μl. Changes in specific miRNAs expressions, including miR-208, -290-295, -345, -743 and -802 were associated with the growth of the mPFC-GBM under muscimol treatment. These findings suggest that GBM growth into the mPFC profoundly impacts cognitive and emotional behaviors which can be improved by muscimol treatment. Considering that the expression levels of targeted miRNAs could be influenced by the growth of the mPFC-GBM, both with or without muscimol treatment, these non-coding RNAs might serve as potential biomarkers for GBM.

Modulating voltage-gated sodium channels to enhance differentiation and sensitize glioblastoma cells to chemotherapy

BACKGROUND

Glioblastoma (GBM) stands as the most prevalent and aggressive form of adult gliomas. Despite the implementation of intensive therapeutic approaches involving surgery, radiation, and chemotherapy, Glioblastoma Stem Cells contribute to tumor recurrence and poor prognosis. The induction of Glioblastoma Stem Cells differentiation by manipulating the transcriptional machinery has emerged as a promising strategy for GBM treatment. Here, we explored an innovative approach by investigating the role of the depolarized resting membrane potential (RMP) observed in patient-derived GBM sphereforming cell (GSCs), which allows them to maintain a stemness profile when they reside in the G0 phase of the cell cycle.

METHODS

We conducted molecular biology and electrophysiological experiments, both in vitro and in vivo, to examine the functional expression of the voltage-gated sodium channel (Nav) in GSCs, particularly focusing on its cell cycle-dependent functional expression. Nav activity was pharmacologically manipulated, and its effects on GSCs behavior were assessed by live imaging cell cycle analysis, self-renewal assays, and chemosensitivity assays. Mechanistic insights into the role of Nav in regulating GBM stemness were investigated through pathway analysis in vitro and through tumor proliferation assay in vivo.

RESULTS

We demonstrated that Nav is functionally expressed by GSCs mainly during the G0 phase of the cell cycle, suggesting its pivotal role in modulating the RMP. The pharmacological blockade of Nav made GBM cells more susceptible to temozolomide (TMZ), a standard drug for this type of tumor, by inducing cell cycle re-entry from G0 phase to G1/S transition. Additionally, inhibition of Nav substantially influenced the self-renewal and multipotency features of GSCs, concomitantly enhancing their degree of differentiation. Finally, our data suggested that Nav positively regulates GBM stemness by depolarizing the RMP and suppressing the ERK signaling pathway. Of note, in vivo proliferation assessment confirmed the increased susceptibility to TMZ following pharmacological blockade of Nav.

CONCLUSIONS

This insight positions Nav as a promising prognostic biomarker and therapeutic target for GBM patients, particularly in conjunction with temozolomide treatment.

Gliomagenesis, Epileptogenesis, and Remodeling of Neural Circuits: Relevance for Novel Treatment Strategies in Low- and High-Grade Gliomas

Gliomas present a complex challenge in neuro-oncology, often accompanied by the debilitating complication of epilepsy. Understanding the biological interaction and common pathways between gliomagenesis and epileptogenesis is crucial for improving the current understanding of tumorigenesis and also for developing effective management strategies. Shared genetic and molecular mechanisms, such as IDH mutations and dysregulated glutamate signaling, contribute to both tumor progression and seizure development. Targeting these pathways, such as through direct inhibition of mutant IDH enzymes or modulation of glutamate receptors, holds promise for improving patient outcomes. Additionally, advancements in surgical techniques, like supratotal resection guided by connectomics, offer opportunities for maximally safe tumor resection and enhanced seizure control. Advanced imaging modalities further aid in identifying epileptogenic foci and tailoring treatment approaches based on the tumor's metabolic characteristics. This review aims to explore the complex interplay between gliomagenesis, epileptogenesis, and neural circuit remodeling, offering insights into shared molecular pathways and innovative treatment strategies to improve outcomes for patients with gliomas and associated epilepsy.

Glioblastoma Therapy: Past, Present and Future

Glioblastoma (GB) stands out as the most prevalent and lethal form of brain cancer. Although great efforts have been made by clinicians and researchers, no significant improvement in survival has been achieved since the Stupp protocol became the standard of care (SOC) in 2005. Despite multimodality treatments, recurrence is almost universal with survival rates under 2 years after diagnosis. Here, we discuss the recent progress in our understanding of GB pathophysiology, in particular, the importance of glioma stem cells (GSCs), the tumor microenvironment conditions, and epigenetic mechanisms involved in GB growth, aggressiveness and recurrence. The discussion on therapeutic strategies first covers the SOC treatment and targeted therapies that have been shown to interfere with different signaling pathways (pRB/CDK4/RB1/P16ink4, TP53/MDM2/P14arf, PI3k/Akt-PTEN, RAS/RAF/MEK, PARP) involved in GB tumorigenesis, pathophysiology, and treatment resistance acquisition. Below, we analyze several immunotherapeutic approaches (i.e., checkpoint inhibitors, vaccines, CAR-modified NK or T cells, oncolytic virotherapy) that have been used in an attempt to enhance the immune response against GB, and thereby avoid recidivism or increase survival of GB patients. Finally, we present treatment attempts made using nanotherapies (nanometric structures having active anti-GB agents such as antibodies, chemotherapeutic/anti-angiogenic drugs or sensitizers, radionuclides, and molecules that target GB cellular receptors or open the blood-brain barrier) and non-ionizing energies (laser interstitial thermal therapy, high/low intensity focused ultrasounds, photodynamic/sonodynamic therapies and electroporation). The aim of this review is to discuss the advances and limitations of the current therapies and to present novel approaches that are under development or following clinical trials.

The role of neurotransmitters in glioblastoma multiforme-associated seizures

GBM, or glioblastoma multiforme, is a brain tumor that poses a great threat to both children and adults, being the primary cause of death related to brain tumors. GBM is often associated with epilepsy, which can be debilitating. Seizures and the development of epilepsy are the primary symptoms that have a severe impact on the quality of life for GBM patients. It is increasingly apparent that the nervous system plays an essential role in the tumor microenvironment for all cancer types, including GBM. In recent years, there has been a growing understanding of how neurotransmitters control the progression of gliomas. Evidence suggests that neurotransmitters and neuromodulators found in the tumor microenvironment play crucial roles in the excitability, proliferation, quiescence, and differentiation of neurons, glial cells, and neural stem cells. The involvement of neurotransmitters appears to play a significant role in various stages of GBM. In this review, the focus is on presenting updated knowledge and emerging ideas regarding the interplay between neurotransmitters and neuromodulators, such as glutamate, GABA, norepinephrine, dopamine, serotonin, adenosine, and their relationship with GBM and the seizures induced by this condition. The review aims to explore the current understanding and provide new insights into the complex interactions between these neurotransmitters and neuromodulators in the context of GBM-related seizures.

Ligand-Gated Ion Channels: Prognostic and Therapeutic Implications for Gliomas

Gliomas are common primary brain malignancies that remain difficult to treat due to their overall aggressiveness and heterogeneity. Although a variety of therapeutic strategies have been employed for the treatment of gliomas, there is increasing evidence that suggests ligand-gated ion channels (LGICs) can serve as a valuable biomarker and diagnostic tool in the pathogenesis of gliomas. Various LGICs, including P2X, SYT16, and PANX2, have the potential to become altered in the pathogenesis of glioma, which can disrupt the homeostatic activity of neurons, microglia, and astrocytes, further exacerbating the symptoms and progression of glioma. Consequently, LGICs, including purinoceptors, glutamate-gated receptors, and Cys-loop receptors, have been targeted in clinical trials for their potential therapeutic benefit in the diagnosis and treatment of gliomas. In this review, we discuss the role of LGICs in the pathogenesis of glioma, including genetic factors and the effect of altered LGIC activity on the biological functioning of neuronal cells. Additionally, we discuss current and emerging investigations regarding the use of LGICs as a clinical target and potential therapeutic for gliomas.