Trends in glioblastoma: outcomes over time and type of intervention: a systematic evidence based analysis

Treatment, healthcare utilization and outcomes in patients with glioblastoma in Ontario: a 10-year cohort study

BACKGROUND AND PURPOSE

Glioblastoma (GBM) is the most common malignant primary brain tumour in adults. Receipt of adjuvant therapies has been shown to exert a significant positive effect on patient survival. Little is known however about how changes in standards of care and healthcare system factors, such as access, affect real-world outcomes. In this study, we provide an overview of GBM in Ontario and examine elements of care, including treatment patterns, healthcare utilization, and overall survival, from 2010 to 2019, to interpret the impact of the changes in practice standards and expansion of the care network within this period.

METHODS

Using linked health-administrative databases from Ontario, Canada, we conducted a population-based cohort study to examine the clinical and biological characteristics, treatment, and healthcare utilization patterns of adult GBM patients diagnosed between 2010 and 2019. The primary outcomes were enrollment in adjuvant chemoradiation treatment and 1-, 2-, and 5-year survival. All analyses were performed using the Statistical Analysis Software (SAS).

RESULTS

5392 patients were diagnosed with GBM in Ontario from 2010 to 2019 (58% male, 42% female). The median age at diagnosis was 64. Receipt of adjuvant chemoradiation within one year of diagnosis increased from 51% in 2010 to 63% in 2019. 1-year, 2-year, and 5-year overall survival for all patients remained stable, ranging between 40 and 43%, 15-19%, and 5-7%, respectively. For patients above the age of 65, however, 1-year survival increased from 19% in 2010 to 26% in 2019.

INTERPRETATION

Regionalization enabled access to treatment closer to home for many patients. Over the last decade, receipt of adjuvant chemoradiation increased among elderly patients, but the improvement in 1-year overall survival over time was accounted for by sociodemographic and clinical covariates. Our findings support the efforts for regionalization of services to improve accessibility.

CONCLUSION

This Ontario-based study provides insight into the effect of practice evolution and healthcare utilization on the overall survival of patients with GBM. Overall survival for most patients with glioblastoma has remained stagnant over the past decade. Changes in treatment standards and expansion of access to treating centres have been associated with prolonged survival in elderly glioblastoma patients.

Glioblastoma and brain connectivity: the need for a paradigm shift

Despite substantial advances in cancer treatment, for patients with glioblastoma prognosis remains bleak. The emerging field of cancer neuroscience reveals intricate functional interplays between glioblastoma and the cellular architecture of the brain, encompassing neurons, glia, and vessels. New findings underscore the role of structural and functional connections within hierarchical networks, known as the connectome. These connections contribute to the location, spread, and recurrence of a glioblastoma, and a patient's overall survival, revealing a complex interplay between the tumour and the CNS. This mounting evidence prompts a paradigm shift, challenging the perception of glioblastomas as mere foreign bodies within the brain. Instead, these tumours are intricately woven into the structural and functional fabric of the brain. This radical change in thinking holds profound implications for the understanding and treatment of glioblastomas, which could unveil new prognostic factors and surgical strategies and optimise radiotherapy. Additionally, a connectivity approach suggests that non-invasive brain stimulation could disrupt pathological neuron-glioma interactions within specific networks.

Recurrent Glioblastoma-Molecular Underpinnings and Evolving Treatment Paradigms

Glioblastoma is the most common and lethal central nervous system malignancy with a median survival after progression of only 6-9 months. Major biochemical mechanisms implicated in glioblastoma recurrence include aberrant molecular pathways, a recurrence-inducing tumor microenvironment, and epigenetic modifications. Contemporary standard-of-care (surgery, radiation, chemotherapy, and tumor treating fields) helps to control the primary tumor but rarely prevents relapse. Cytoreductive treatment such as surgery has shown benefits in recurrent glioblastoma; however, its use remains controversial. Several innovative treatments are emerging for recurrent glioblastoma, including checkpoint inhibitors, chimeric antigen receptor T cell therapy, oncolytic virotherapy, nanoparticle delivery, laser interstitial thermal therapy, and photodynamic therapy. This review seeks to provide readers with an overview of (1) recent discoveries in the molecular basis of recurrence; (2) the role of surgery in treating recurrence; and (3) novel treatment paradigms emerging for recurrent glioblastoma.

Strategies to Improve Drug Delivery Across the Blood-Brain Barrier for Glioblastoma

PURPOSE OF REVIEW

Glioblastoma remains resistant to most conventional treatments. Despite scientific advances in the past three decades, there has been a dearth of effective new treatments. New approaches to drug delivery and clinical trial design are needed.

RECENT FINDINGS

We discuss how the blood-brain barrier and tumor microenvironment pose challenges for development of effective therapies for glioblastoma. Next, we discuss treatments in development that aim to overcome these barriers, including novel drug designs such as nanoparticles and antibody-drug conjugates, novel methods of drug delivery, including convection-enhanced and intra-arterial delivery, and novel methods to enhance drug penetration, such as blood-brain barrier disruption by focused ultrasound and laser interstitial thermal therapy. Lastly, we address future opportunities, positing combination therapy as the best strategy for effective treatment, neoadjuvant and window-of-opportunity approaches to simultaneously enhance therapeutic effectiveness with interrogation of on-treatment biologic endpoints, and adaptive platform and basket trials as imperative for future trial design. New approaches to GBM treatment should account for the blood-brain barrier and immunosuppression by improving drug delivery, combining treatments, and integrating novel clinical trial designs.

Endovascular Applications for the Management of High-Grade Gliomas in the Modern Era

High-grade gliomas (HGGs) have a poor prognosis and are difficult to treat. This review examines the evolving landscape of endovascular therapies for HGGs. Recent advances in endovascular catheter technology and delivery methods allow for super-selective intra-arterial cerebral infusion (SSIACI) with increasing precision. This treatment modality may offer the ability to deliver anti-tumoral therapies directly to tumor regions while minimizing systemic toxicity. However, challenges persist, including blood-brain barrier (BBB) penetration, hemodynamic complexities, and drug-tumor residence time. Innovative adjunct techniques, such as focused ultrasound (FUS) and hyperosmotic disruption, may facilitate BBB disruption and enhance drug penetration. However, hemodynamic factors that limit drug residence time remain a limitation. Expanding therapeutic options beyond chemotherapy, including radiotherapy and immunobiologics, may motivate future investigations. While preclinical and clinical studies demonstrate moderate efficacy, larger randomized trials are needed to validate the clinical benefits. Additionally, future directions may involve endovascular sampling for peri-tumoral surveillance; changes in drug formulations to prolong residence time; and the exploration of non-pharmaceutical therapies, like radioembolization and photodynamic therapy. Endovascular strategies hold immense potential in reshaping HGG treatment paradigms, offering targeted and minimally invasive approaches. However, overcoming technical challenges and validating clinical efficacy remain paramount for translating these advancements into clinical care.

Long noncoding RNA UNC5B-AS1 suppresses cell proliferation by sponging miR-24-3p in glioblastoma multiforme

BACKGROUND

Glioblastoma multiforme (GBM) is the most common primary CNS tumor, characterized by high mortality and heterogeneity. However, the related lncRNA signatures and their target microRNA (miRNA) for GBM are still mostly unknown. Therefore, it is critical that we discover lncRNA markers in GBM and their biological activities.

MATERIALS AND METHODS

GBM-related RNA-seq data were obtained from the Cancer Genome Atlas (TCGA) database. The "edger" R package was used for differently expressed lncRNAs (DELs) identification. Then, we forecasted prospective miRNAs that might bind to lncRNAs by Cytoscape software. Survival analysis of those miRNAs was examined by the starBase database, and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of the miRNAs' target genes was conducted by the Gene Set Enrichment Analysis (GSEA) database and R software. Moreover, the proliferative ability of unc-5 netrin receptor B antisense RNA 1 (UNC5B-AS1) cells was evaluated by Cell Counting Kit-8 (CCK-8) analysis. Mechanistically, the regulatory interaction between UNC5B-AS1 and miRNA in GBM biological processes was studied using CCK-8 analysis.

RESULTS

Our results indicated that overexpression of UNC5B-AS1 has been shown to suppress GBM cell growth. Mechanistically, miR-24-3p in GBM was able to alleviate the anti-oncogenic effects of UNC5B-AS1 on cell proliferation.

CONCLUSION

The discovery of the novel UNC5B-AS1-miR-24-3p network suggests possible lncRNA and miRNA roles in the development of GBM, which may have significant ramifications for the analysis of clinical prognosis and the development of GBM medications.

Incidence trends of adult glioma in Norway and its association with occupation and education: A registry-based cohort study

BACKGROUND

Gliomas constitute 75 % of all malignant primary adult brain tumors. Being the most frequent histologic subtype, glioblastomas (GBMs) cause substantial morbidity and mortality worldwide and the Nordic countries have some of the highest incidence rates in the world. Therefore, we investigated the incidence of gliomas in Norway including time trends and associations with education and occupation.

METHODS

We retrieved individual-level data from databases at Statistics Norway containing information on education and occupation and linked them to data on adult glioma patients diagnosed during 2004-21 from the Cancer Registry of Norway. Age-standardized incidence rates (ASIRs) (World Standard Population) were calculated and analyzed with regards to sex and morphology. Poisson regression was used to test for time-trends, and to analyze the associations between education, occupation and glioma incidence, adjusted for age, sex, and calendar year. Estimates were reported as incidence rate ratios (IRRs) with 95 % confidence intervals (CIs).

RESULTS

The overall ASIR of gliomas (per 100,000 person-years) was 7.1 (95 % CI 6.9-7.3), with no specific time trend during the study period. The incidence increased with age. Compared to the other subtypes, GBMs were diagnosed at older ages. The risks of developing glioma overall and GBM were associated with occupation but not with educational level. The relative risk of glioma and GBM were respectively 1.17 (95 % CI 1.05-1.31) and 1.17 (95 % CI 1.02-1.35) among high-skilled white-collar workers compared to blue-collar workers.

CONCLUSIONS

The overall and sex-specific ASIRs of gliomas and GBMs did not show any noticeable time trends. The higher risk of developing glioma overall and GBM in high-skilled white-collar workers compared to blue-collar workers calls for further investigations.

Intraoperative ultrasound for surgical resection of high-grade glioma and glioblastoma: a meta-analysis of 732 patients

PURPOSE

Here, we conducted a meta-analysis to explore the use of intraoperative ultrasound (iUS)-guided resection in patients diagnosed with high-grade glioma (HGG) or glioblastoma (GBM). Our aim was to determine whether iUS improves clinical outcomes compared to conventional neuronavigation (CNN).

METHODS

Databases were searched until April 21, 2023 for randomized controlled trials (RCTs) and observational cohort studies that compared surgical outcomes for patients with HGG or GBM with the use of either iUS in addition to standard approach or CNN. The primary outcome was overall survival (OS). Secondary outcomes include volumetric extent of resection (EOR), gross total resection (GTR), and progression-free survival (PFS). Outcomes were analyzed by determining pooled relative risk ratios (RR), mean difference (MD), and standardized mean difference (SMD) using random-effects model.

RESULTS

Of the initial 867 articles, only 7 articles specifically met the inclusion criteria (1 RCT and 6 retrospective cohorts). The analysis included 732 patients. Compared to CNN, the use of iUS was associated with higher OS (SMD = 0.26,95%CI=[0.12,0.39]) and GTR (RR = 2.02; 95% CI=[1.31,3.1]) for both HGG and GBM. There was no significant difference in PFS or EOR.

CONCLUSION

The use of iUS in surgical resections for HGG and GBM can improve OS and GTR compared to CNN, but it did not affect PFS. These results suggest that iUS reduces mortality associated with HGG and GBM but not the risk of recurrence. These results can provide valuable cost-effective interventions for neurosurgeons in HGG and GBM surgery.

Discovery of N-alkyl-N-benzyl thiazoles as novel TRPC antagonists for the treatment of glioblastoma multiforme

Glioblastoma multiforme represents a substantial clinical challenge. Transient receptor potential channel (TRPC) antagonists might provide new therapeutic options for this aggressive cancer. In this study, a series of N-alkyl-N-benzoyl and N-alkyl-N-benzyl thiazoles were designed and prepared using a scaffold-hopping strategy and evaluated as TRPC6 antagonists. This resulted in the discovery of 15g, a potent TRPC antagonist that exhibited suitable inhibitory micromolar activities against TRPC3, TRPC4, TRPC5, TPRC6, and TRPC7 and displayed noteworthy anti-glioblastoma efficacy in vitro against U87 cell lines. In addition, 15g featured an acceptable pharmacokinetic profile and exhibited better in vivo potency (25 mg/kg/d) than the frontline therapeutic agent temozolomide (50 mg/kg/d) in xenograft models. Taken together, the TRPC antagonist 15g represents a promising lead compound for developing new anti-glioblastoma agents.

Small Molecule Immunomodulators as Next-Generation Therapeutics for Glioblastoma

Glioblastoma (GBM), the most aggressive astrocytic glioma, remains a therapeutic challenge despite multimodal approaches. Immunotherapy holds promise, but its efficacy is hindered by the highly immunosuppressive GBM microenvironment. This review underscores the urgent need to comprehend the intricate interactions between glioma and immune cells, shaping the immunosuppressive tumor microenvironment (TME) in GBM. Immunotherapeutic advancements have shown limited success, prompting exploration of immunomodulatory approaches targeting tumor-associated macrophages (TAMs) and microglia, constituting a substantial portion of the GBM TME. Converting protumor M2-like TAMs to antitumor M1-like phenotypes emerges as a potential therapeutic strategy for GBM. The blood-brain barrier (BBB) poses an additional challenge to successful immunotherapy, restricting drug delivery to GBM TME. Research efforts to enhance BBB permeability have mainly focused on small molecules, which can traverse the BBB more effectively than biologics. Despite over 200 clinical trials for GBM, studies on small molecule immunomodulators within the GBM TME are scarce. Developing small molecules with optimal brain penetration and selectivity against immunomodulatory pathways presents a promising avenue for combination therapies in GBM. This comprehensive review discusses various immunomodulatory pathways in GBM progression with a focus on immune checkpoints and TAM-related targets. The exploration of such molecules, with the capacity to selectively target key immunomodulatory pathways and penetrate the BBB, holds the key to unlocking new combination therapy approaches for GBM.

Adjuvant convection-enhanced delivery for the treatment of brain tumors

BACKGROUND

Malignant gliomas are a therapeutic challenge and remain nearly uniformly fatal. While new targeted chemotherapeutic agentsagainst malignant glioma have been developed in vitro, these putative therapeutics have not been translated into successful clinical treatments. The lack of clinical effectiveness can be the result of ineffective biologic strategies, heterogeneous tumor targets and/or the result of poortherapeutic distribution to malignant glioma cells using conventional nervous system delivery modalities (intravascular, cerebrospinal fluid and/orpolymer implantation), and/or ineffective biologic strategies.

METHODS

The authors performed a review of the literature for the terms "convection enhanced delivery", "glioblastoma", and "glioma". Selectclinical trials were summarized based on their various biological mechanisms and technological innovation, focusing on more recently publisheddata when possible.

RESULTS

We describe the properties, features and landmark clinical trials associated with convection-enhanced delivery for malignant gliomas.We also discuss future trends that will be vital to CED innovation and improvement.

CONCLUSION

Efficacy of CED for malignant glioma to date has been mixed, but improvements in technology and therapeutic agents arepromising.

Unsupervised machine learning models reveal predictive clinical markers of glioblastoma patient survival using white blood cell counts prior to initiating chemoradiation

Background

Glioblastoma is a malignant brain tumor requiring careful clinical monitoring even after primary management. Personalized medicine has suggested the use of various molecular biomarkers as predictors of patient prognosis or factors utilized for clinical decision-making. However, the accessibility of such molecular testing poses a constraint for various institutes requiring identification of low-cost predictive biomarkers to ensure equitable care.

Methods

We collected retrospective data from patients seen at Ohio State University, University of Mississippi, Barretos Cancer Hospital (Brazil), and FLENI (Argentina) who were managed for glioblastoma-amounting to 581 patient records documented using REDCap. Patients were evaluated using an unsupervised machine learning approach comprised of dimensionality reduction and eigenvector analysis to visualize the inter-relationship of collected clinical features.

Results

We discovered that the serum white blood cell (WBC) count of a patient during baseline planning for treatment was predictive of overall survival with an over 6-month median survival difference between the upper and lower quartiles of WBC count. By utilizing an objective PD-L1 immunohistochemistry quantification algorithm, we were further able to identify an increase in PD-L1 expression in glioblastoma patients with high serum WBC counts.

Conclusions

These findings suggest that in a subset of glioblastoma patients the incorporation of WBC count and PD-L1 expression in the brain tumor biopsy as simple biomarkers predicting glioblastoma patient survival. Moreover, machine learning models allow the distillation of complex clinical data sets to uncover novel and meaningful clinical relationships.

Behavior of glioblastoma brain tumor stem cells following a suborbital rocket flight: reaching the "edge" of outer space

The emerging arena of space exploration has created opportunities to study cancer cell biology in the environments of microgravity and hypergravity. Studying cellular behavior in altered gravity conditions has allowed researchers to make observations of cell function that would otherwise remain unnoticed. The patient-derived QNS108 brain tumor initiating cell line (BTIC), isolated from glioblastoma (GBM) tissue, was launched on a suborbital, parabolic rocket flight conducted by EXOS Aerospace Systems & Technologies. All biologicals and appropriate ground controls were secured post-launch and transported back to our research facility. Cells from the rocket-flight and ground-based controls were isolated from the culture containers and expanded on adherent flasks for two weeks. In vitro migration, proliferation, and stemness assays were performed. Following cell expansion, male nude mice were intracranially injected with either ground-control (GC) or rocket-flight (RF) exposed cells to assess tumorigenic capacity (n = 5 per group). Patient-derived QNS108 BTICs exposed to RF displayed more aggressive tumor growth than the GC cells in vitro and in vivo. RF cells showed significantly higher migration (p < 0.0000) and stemness profiles (p < 0.01) when compared to GC cells. Further, RF cells, when implanted in vivo in the brain of rodents had larger tumor-associated cystic growth areas (p = 0.00029) and decreased survival (p = 0.0172) as compared to those animals that had GC cells implanted.

Improving the efficacy of anti-EGFR drugs in GBM: Where we are going?

The therapies targeting mutations of driver genes in cancer have advanced into clinical trials for a variety of tumors. In glioblastoma (GBM), epidermal growth factor receptor (EGFR) is the most commonly mutated oncogene, and targeting EGFR has been widely investigated as a promising direction. However, the results of EGFR pathway inhibitors have not been satisfactory. Limited blood-brain barrier (BBB) permeability, drug resistance, and pathway compensation mechanisms contribute to the failure of anti-EGFR therapies. This review summarizes recent research advances in EGFR-targeted therapy for GBM and provides insight into the reasons for the unsatisfactory results of EGFR-targeted therapy. By combining the results of preclinical studies with those of clinical trials, we discuss that improved drug penetration across the BBB, the use of multi-target combinations, and the development of peptidomimetic drugs under the premise of precision medicine may be promising strategies to overcome drug resistance in GBM.

Identification of cytokine-predominant immunosuppressive class and prognostic risk signatures in glioma

PURPOSE

The advent of immune checkpoint blockade (ICB) therapies this year has changed the way glioblastoma (GBM) is treated. Meanwhile, some patients with strong PD-L1 expression remain immune checkpoint resistant. To better understand the molecular processes that influence the immune environment, there is an urgent need to characterize the immunosuppressive tumor microenvironment and identify biomarkers to predict patient survival outcomes.

PATIENTS AND METHODS

Our study analyzed RNA-sequencing data from 178 GBM samples. Their unique gene expression patterns in the tumor microenvironment were analyzed by an unsupervised clustering algorithm. Through these expression patterns, a panel of T-cell exhaustion signatures, immunosuppressive cells, and clinical features correlates with immunotherapy response. The presence or absence of immune status and prognostic signatures was then validated with the test dataset.

RESULTS

38.2% of GBM patients showed increased expression of anti-inflammatory cytokines, significant enrichment of T cell exhaustion signals, higher proportion of immunosuppressive cells (macrophages and CD4 regulatory T cells) and nine inhibitory checkpoints (CTLA4, PDCD1, LAG3, BTLA, TIGIT, HAVCR2, IDO1, SIGLEC7, and VISTA). The immunodepleted class (IDC) was used to classify these immunocompromised individuals. Despite the high density of tumor-infiltrating lymphocytes shown by IDC, such patients have a poor prognosis. Although PD-L1 was highly expressed in IDC, it suggested that there might be ICB resistance. There are many IDC predictive signatures to discover.

CONCLUSION

PD-1 is strongly expressed in a novel immunosuppressive class of GBM, but this cluster may be resistant to ICB therapy. A comprehensive description of this drug-resistant tumor microenvironment could provide new insights into drug resistance mechanisms and improved immunotherapy techniques.

Clinical and molecular analysis of cilia-associated gene signature for prognostic prediction in glioma

PURPOSE

Glioma is a highly malignant and unfavorable cancer in the brain. Recent evidence highlights the vital role of cilia-related pathways as novel regulators of glioma development. However, the prognostic potential of ciliary pathways in glioma is still ambiguous. In this study, we aim to construct a gene signature using cilia-related genes to facilitate the prognostication of glioma.

METHODS

A multi-stage approach was employed to build the ciliary gene signature for prognostication of glioma. The strategy involved the implementation of univariate, LASSO, and stepwise multivariate Cox regression analyses based on TCGA cohort, followed by independent validation in CGGA and REMBRANDT cohort. The study further revealed molecular differences at the genomic, transcriptomic, and proteomic levels between distinct groups.

RESULTS

A prognostic tool utilizing a 9-gene signature based on ciliary pathways was developed to assess the clinical outcomes of glioma patients. The risk scores generated by the signature demonstrated a negative correlation with patient survival rates. The validation of the signature in an independent cohort reinforced its prognostic capabilities. In-depth analysis uncovered distinctive molecular characteristics at the genomic, transcriptomic, and protein-interactive levels in the high- and low-risk groups. Furthermore, the gene signature was able to predict the sensitivity of glioma patients to conventional chemotherapeutic drugs.

CONCLUSION

This study has established the utility of a ciliary gene signature as a reliable prognostic predictor of glioma patient survival. Findings not only enhance our comprehension of the intricate molecular mechanisms of cilia pathways in glioma, but also hold significant clinical implications in directing chemotherapeutic strategies.

Glioma Stem Cells Are Sensitized to BCL-2 Family Inhibition by Compromising Histone Deacetylases

Glioblastoma (GBM) remains an incurable disease with an extremely high five-year recurrence rate. We studied apoptosis in glioma stem cells (GSCs) in response to HDAC inhibition (HDACi) combined with MEK1/2 inhibition (MEKi) or BCL-2 family inhibitors. MEKi effectively combined with HDACi to suppress growth, induce cell cycle defects, and apoptosis, as well as to rescue the expression of the pro-apoptotic BH3-only proteins BIM and BMF. A RNAseq analysis of GSCs revealed that HDACi repressed the pro-survival BCL-2 family genes MCL1 and BCL-XL. We therefore replaced MEKi with BCL-2 family inhibitors and observed enhanced apoptosis. Conversely, a ligand for the cancer stem cell receptor CD44 led to reductions in BMF, BIM, and apoptosis. Our data strongly support further testing of HDACi in combination with MEKi or BCL-2 family inhibitors in glioma.

Virus-like Silica Nanoparticles Improve Permeability of Macromolecules across the Blood-Brain Barrier In Vitro

The presence of the blood-brain barrier (BBB) limits the delivery of therapies into the brain. There has been significant interest in overcoming the BBB for the effective delivery of therapies to the brain. Inorganic nanomaterials, especially silica nanoparticles with varying surface chemistry and surface topology, have been recently used as permeation enhancers for oral protein delivery. In this context, nanoparticles with varying sizes and surface chemistries have been employed to overcome this barrier; however, there is no report examining the effect of nanoscale roughness on BBB permeability. This paper reports the influence of nanoscale surface roughness on the integrity and permeability of the BBB in vitro, using smooth surface Stöber silica nanoparticles (60 nm) compared to rough surface virus-like silica nanoparticles (VSNP, 60 nm). Our findings reveal that VSNP (1 mg/mL) with virus-mimicking-topology spiky surface have a greater effect on transiently opening endothelial tight junctions of the BBB than the same dose of Stöber silica nanoparticles (1 mg/mL) by increasing the FITC-Dextran (70 kDa) permeability 1.9-fold and by decreasing the trans-endothelial electrical resistance (TEER) by 2.7-fold. This proof-of-concept research paves the way for future studies to develop next-generation tailored surface-modified silica nanoparticles, enabling safe and efficient macromolecule transport across the BBB.

TRIB1 confers therapeutic resistance in GBM cells by activating the ERK and Akt pathways

GBM (Glioblastoma) is the most lethal CNS (Central nervous system) tumor in adults, which inevitably develops resistance to standard treatments leading to recurrence and mortality. TRIB1 is a serine/threonine pseudokinase which functions as a scaffold platform that initiates degradation of its substrates like C/EBPα through the ubiquitin proteasome system and also activates MEK and Akt signaling. We found that increased TRIB1 gene expression associated with worse overall survival of GBM patients across multiple cohorts. Importantly, overexpression of TRIB1 decreased RT/TMZ (radiation therapy/temozolomide)-induced apoptosis in patient derived GBM cell lines in vitro. TRIB1 directly bound to MEK and Akt and increased ERK and Akt phosphorylation/activation. We also found that TRIB1 protein expression was maximal during G2/M transition of cell cycle in GBM cells. Furthermore, TRIB1 bound directly to HDAC1 and p53. Importantly, mice bearing TRIB1 overexpressing tumors had worse overall survival. Collectively, these data suggest that TRIB1 induces resistance of GBM cells to RT/TMZ treatments by activating the cell proliferation and survival pathways thus providing an opportunity for developing new targeted therapeutics.

Perivascular invasion of primary human glioblastoma cells in organotypic human brain slices: human cells migrating in human brain

INTRODUCTION

Glioblastoma (GBM) is an aggressive primary brain cancer. Lack of effective therapy is related to its highly invasive nature. GBM invasion has been studied with reductionist systems that do not fully recapitulate the cytoarchitecture of the brain. We describe a human-derived brain organotypic model to study the migratory properties of GBM IDH-wild type ex vivo.

METHODS

Non-tumor brain samples were obtained from patients undergoing surgery (n = 7). Organotypic brain slices were prepared, and green fluorescent protein (GFP)-labeled primary human GBM IDH-wild type cells (GBM276, GBM612, GBM965) were placed on the organotypic slice. Migration was evaluated via microscopy and immunohistochemistry.

RESULTS

After placement, cells migrated towards blood vessels; initially migrating with limited directionality, sending processes in different directions, and increasing their speed upon contact with the vessel. Once merged, migration speed decreased and continued to decrease with time (p < 0.001). After perivascular localization, migration is limited along the blood vessels in both directions. The percentage of cells that contact blood vessels and then continue to migrate along the vessel was 92.5% (- 3.9/ + 2.9)% while the percentage of cells that migrate along the blood vessel and leave was 7.5% (- 2.9/ + 3.9) (95% CI, Clopper-Pearson (exact); n = 256 cells from six organotypic cultures); these percentages are significantly different from the random (50%) null hypothesis (z = 13.6; p < 10-7). Further, cells increase their speed in response to a decrease in oxygen tension from atmospheric normoxia (20% O2) to anoxia (1% O2) (p = 0.033).

CONCLUSION

Human organotypic models can accurately study cell migration ex vivo. GBM IDH-wild type cells migrate toward the perivascular space in blood vessels and their migratory parameters change once they contact vascular structures and under hypoxic conditions. This model allows the evaluation of GBM invasion, considering the human brain microenvironment when cells are removed from their native niche after surgery.

FBP1 is a potential prognostic biomarker and correlated with tumor immunosuppressive microenvironment in glioblastoma

Hypoxia has been shown to contribute to tumor immunosuppressive microenvironment and is an effective prognostic indicator. This study aimed to screen prognostic hypoxia-related genes (HRGs) in glioblastoma and investigate the association between HRGs and tumor immunosuppressive microenvironment. The glioblastoma-related mRNA data were collected from TCGA, GEO, and CGGA databases. Totally 200 HRGs were obtained from the GSEA website. The prognostic HRGs were screened by univariate Cox regression analysis. Somatic mutation data of glioblastoma from TCGA was visualized using the "maftools" of R package. Immune cell infiltration proportions were calculated by CIBERSORT. The TISIDB online tool was applied to analyze the relationship between HRGs and immunoinhibitors as well as the HRG expression in different glioblastoma immune and molecular subtypes. Hub gene's mRNA and protein levels in cell lines were determined by qRT-PCR and western blot, respectively. The effects of hub gene knockdown on cell viability and migration ability were evaluated employing CCK8 and wound healing assays. The univariate Cox regression showed that high level of FBP1 (fructose-1,6-bisphosphatase 1) was a poor prognostic biomarker, and FBP1 was mainly expressed in lymphocyte depleted immune subtype of glioblastoma. High FBP1 mRNA and protein levels have been successfully validated in vitro. The somatic mutation analysis suggested that TP53 mutation rate was the highest in the high FBP1 glioblastoma group, while EGFR mutation rate was the highest in the low FBP1 glioblastoma group. In the high FBP1 group, the infiltration proportions and types of immune cells were less, dominated by macrophages M2, and the expression of CTLA4, LAG3, TIGIT, PDL1, and PDL2 was significantly upregulated. The expression of FBP1 was positively correlated with several immunoinhibitors, such as IL-10 and TGFβ-1. In conclusion, we demonstrated that FBP1 could serve as a prognostic biomarker for glioblastoma. The immune microenvironment in the high FBP1 group might be suppressed by up-regulating immune checkpoints and immunoinhibitors.

Cancer cell-mitochondria hybrid membrane coated Gboxin loaded nanomedicines for glioblastoma treatment

Glioblastoma (GBM) remains the most lethal malignant tumours. Gboxin, an oxidative phosphorylation inhibitor, specifically restrains GBM growth by inhibiting the activity of F₀F₁ ATPase complex V. However, its anti-GBM effect is seriously limited by poor blood circulation, the blood brain barrier (BBB) and non-specific GBM tissue/cell uptake, leading to insufficient Gboxin accumulation at GBM sites, which limits its further clinical application. Here we present a biomimetic nanomedicine (HM-NPs@G) by coating cancer cell-mitochondria hybrid membrane (HM) on the surface of Gboxin-loaded nanoparticles. An additional design element uses a reactive oxygen species responsive polymer to facilitate at-site Gboxin release. The HM camouflaging endows HM-NPs@G with unique features including good biocompatibility, improved pharmacokinetic profile, efficient BBB permeability and homotypic dual tumour cell and mitochondria targeting. The results suggest that HM-NPs@G achieve improved blood circulation (4.90 h versus 0.47 h of free Gboxin) and tumour accumulation (7.73% ID/g versus 1.06% ID/g shown by free Gboxin). Effective tumour inhibition in orthotopic U87MG GBM and patient derived X01 GBM stem cell xenografts in female mice with extended survival time and negligible side effects are also noted. We believe that the biomimetic Gboxin nanomedicine represents a promising treatment for brain tumours with clinical potential.

Silica nanoparticles for brain cancer

INTRODUCTION

Brain cancer is a debilitating disease with a poor survival rate. There are significant challenges for effective treatment due to the presence of the blood-brain barrier (BBB) and blood-tumor barrier (BTB) which impedes drug delivery to tumor sites. Many nanomedicines have been tested in improving both the survival and quality of life of patients with brain cancer with the recent focus on inorganic nanoparticles such as silica nanoparticles (SNPs). This review examines the use of SNPs as a novel approach for diagnosing, treating, and theranostics of brain cancer.

AREAS COVERED

The review provides an overview of different brain cancers and current therapies available. A special focus on the key functional properties of SNPs is discussed which makes them an attractive material in the field of onco-nanomedicine. Strategies to overcome the BBB using SNPs are analyzed. Furthermore, recent advancements in active targeting, combination therapies, and innovative nanotherapeutics utilizing SNPs are discussed. Safety considerations, toxicity profiles, and regulatory aspects are addressed to provide an understanding of SNPs' translational potential.

EXPERT OPINION

SNPs have tremendous prospects in brain cancer research. The multifunctionality of SNPs has the potential to overcome both the BBB and BTB limitations and can be used for brain cancer imaging, drug delivery, and theranostics. The insights provided will facilitate the development of next-generation, innovative strategies, guiding future research toward improved diagnosis, targeted therapy, and better outcomes in brain cancer patients.

Elevated FOXG1 in glioblastoma stem cells cooperates with Wnt/β-catenin to induce exit from quiescence

Glioblastoma (GBM) stem cells (GSCs) display phenotypic and molecular features reminiscent of normal neural stem cells and exhibit a spectrum of cell cycle states (dormant, quiescent, proliferative). However, mechanisms controlling the transition from quiescence to proliferation in both neural stem cells (NSCs) and GSCs are poorly understood. Elevated expression of the forebrain transcription factor FOXG1 is often observed in GBMs. Here, using small-molecule modulators and genetic perturbations, we identify a synergistic interaction between FOXG1 and Wnt/β-catenin signaling. Increased FOXG1 enhances Wnt-driven transcriptional targets, enabling highly efficient cell cycle re-entry from quiescence; however, neither FOXG1 nor Wnt is essential in rapidly proliferating cells. We demonstrate that FOXG1 overexpression supports gliomagenesis in vivo and that additional β-catenin induction drives accelerated tumor growth. These data indicate that elevated FOXG1 cooperates with Wnt signaling to support the transition from quiescence to proliferation in GSCs.

Identification of immunosuppressive signature subtypes and prognostic risk signatures in triple-negative breast cancer

Purpose

Immune checkpoint blockade (ICB) therapy has transformed the treatment of triple-negative breast cancer (TNBC) in recent years. However, some TNBC patients with high programmed death-ligand 1 (PD-L1) expression levels develop immune checkpoint resistance. Hence, there is an urgent need to characterize the immunosuppressive tumor microenvironment and identify biomarkers to construct prognostic models of patient survival outcomes in order to understand biological mechanisms operating within the tumor microenvironment.

Patients and methods

RNA sequence (RNA-seq) data from 303 TNBC samples were analyzed using an unsupervised cluster analysis approach to reveal distinctive cellular gene expression patterns within the TNBC tumor microenvironment (TME). A panel of T cell exhaustion signatures, immunosuppressive cell subtypes and clinical features were correlated with the immunotherapeutic response, as assessed according to gene expression patterns. The test dataset was then used to confirm the occurrence of immune depletion status and prognostic features and to formulate clinical treatment recommendations. Concurrently, a reliable risk prediction model and clinical treatment strategy were proposed based on TME immunosuppressive signature differences between TNBC patients with good versus poor survival status and other clinical prognostic factors.

Results

Significantly enriched TNBC microenvironment T cell depletion signatures were detected in the analyzed RNA-seq data. A high proportion of certain immunosuppressive cell subtypes, 9 inhibitory checkpoints and enhanced anti-inflammatory cytokine expression profiles were noted in 21.4% of TNBC patients that led to the designation of this group of immunosuppressed patients as the immune depletion class (IDC). Although IDC group TNBC samples contained tumor-infiltrating lymphocytes present at high densities, IDC patient prognosis was poor. Notably, PD-L1 expression was relatively elevated in IDC patients that indicated their cancers were resistant to ICB treatment. Based on these findings, a set of gene expression signatures predicting IDC group PD-L1 resistance was identified then used to develop risk models for use in predicting clinical therapeutic outcomes.

Conclusion

A novel TNBC immunosuppressive tumor microenvironment subtype associated with strong PD-L1 expression and possible resistance to ICB treatment was identified. This comprehensive gene expression pattern may provide fresh insights into drug resistance mechanisms for use in optimizing immunotherapeutic approaches for TNBC patients.

Combination immunotherapy of glioblastoma with dendritic cell cancer vaccines, anti-PD-1 and poly I:C

Glioblastoma (GBM) is a lethal cancer with limited therapeutic options. Dendritic cell (DC)-based cancer vaccines provide a promising approach for GBM treatment. Clinical studies suggest that other immunotherapeutic agents may be combined with DC vaccines to further enhance antitumor activity. Here, we report a GBM case with combination immunotherapy consisting of DC vaccines, anti-programmed death-1 (anti-PD-1) and poly I:C as well as the chemotherapeutic agent cyclophosphamide that was integrated with standard chemoradiation therapy, and the patient remained disease-free for 69 months. The patient received DC vaccines loaded with multiple forms of tumor antigens, including mRNA-tumor associated antigens (TAA), mRNA-neoantigens, and hypochlorous acid (HOCl)-oxidized tumor lysates. Furthermore, mRNA-TAAs were modified with a novel TriVac technology that fuses TAAs with a destabilization domain and inserts TAAs into full-length lysosomal associated membrane protein-1 to enhance major histocompatibility complex (MHC) class I and II antigen presentation. The treatment consisted of 42 DC cancer vaccine infusions, 26 anti-PD-1 antibody nivolumab administrations and 126 poly I:C injections for DC infusions. The patient also received 28 doses of cyclophosphamide for depletion of regulatory T cells. No immunotherapy-related adverse events were observed during the treatment. Robust antitumor CD4⁺ and CD8⁺ T-cell responses were detected. The patient remains free of disease progression. This is the first case report on the combination of the above three agents to treat glioblastoma patients. Our results suggest that integrated combination immunotherapy is safe and feasible for long-term treatment in this patient. A large-scale trial to validate these findings is warranted.

Wnt Signaling in Brain Tumors: A Challenging Therapeutic Target

The involvement of Wnt signaling in normal tissue homeostasis and disease has been widely demonstrated over the last 20 years. In particular, dysregulation of Wnt pathway components has been suggested as a relevant hallmark of several neoplastic malignancies, playing a role in cancer onset, progression, and response to treatments. In this review, we summarize the current knowledge on the instructions provided by Wnt signaling during organogenesis and, particularly, brain development. Moreover, we recapitulate the most relevant mechanisms through which aberrant Wnt pathway activation may impact on brain tumorigenesis and brain tumor aggressiveness, with a particular focus on the mutual interdependency existing between Wnt signaling components and the brain tumor microenvironment. Finally, the latest anti-cancer therapeutic approaches employing the specific targeting of Wnt signaling are extensively reviewed and discussed. In conclusion, here we provide evidence that Wnt signaling, due to its pleiotropic involvement in several brain tumor features, may represent a relevant target in this context, although additional efforts will be needed to: (i) demonstrate the real clinical impact of Wnt inhibition in these tumors; (ii) overcome some still unsolved concerns about the potential systemic effects of such approaches; (iii) achieve efficient brain penetration.

Comprehensive analysis of oxidative stress-related lncRNA signatures in glioma reveals the discrepancy of prognostic and immune infiltration

Oxidative stress refers to the process of reactive oxide species (ROS) increase in human body due to various factors, which leads to oxidative damage in human tissues. Current studies have confirmed that sustained oxidative stress is one of the distinctive features throughout the development of tumors. Numerous reports have shown that lncRNAs can regulate the process of oxidative stress through multiple pathways. However, the relationship between glioma-associated oxidative stress and lncRNAs is not clearly investigated. RNA sequencing data of GBM (glioblastoma) and LGG (low grade glioma) and corresponding clinical data were retrieved from the TCGA database. Oxidative stress related lncRNAs (ORLs) were identified by Pearson correlation analysis. Prognostic models for 6-ORLs were structured in the training cohort by univariate Cox regression analysis, multivariate Cox regression analysis and LASSO regression analysis. We constructed the nomogram and verified its predictive efficacy by Calibration curves and DCA decision curves. The biological functions and pathways of 6-ORLs-related mRNAs were inferred by Gene Set Enrichment Analysis. Immune cell abundance and immune function associated with risk score (RS) were estimated by ssGSEA, CIBERSORT and MCPcounter synthetically. External validation of the signature was completed using the CGGA-325 and CGGA-693 datasets. 6-ORLs signature-AC083864.2, AC107294.1, AL035446.1, CRNDE, LINC02600, and SNAI3-AS1-were identified through our analysis as being predictive of glioma prognosis. Kaplan-Meier and ROC curves indicated that the signature has a dependable predictive efficacy in the TCGA training cohort, validation cohort and CGGA-325/CGGA-693 test cohort. The 6-ORLs signature were verified to be independent prognostic predictors by multivariate cox regression and stratified survival analysis. Nomogram built with risk scores had strong predictive efficacy for patients' overall survival (OS). The outcomes of the functional enrichment analysis revealing potential molecular regulatory mechanisms for the 6-ORLs. Patients in the high-risk subgroup presented a significant immune microenvironment of macrophage M0 and cancer-associated fibroblast infiltration which was associated with a poorer prognosis. Finally, the expression levels of 6-ORLs in U87/U251/T98/U138 and HA1800 cell lines were verified by RT-qPCR. The nomogram in this study has been made available as a web version for clinicians. This 6-ORLs risk signature has the capabilities to predict the prognosis of glioma patients, assist in evaluating immune infiltration, and assess the efficacy of various anti-tumor systemic therapy regimens.

Thiophene Carboxamide Analogs with Long Alkyl Chains Comprising Ethylene Glycol Units Inhibit Glioblastoma Cell Proliferation by Activating AMPK

Glioblastoma is a refractory malignant tumor that requires novel therapeutic strategies for effective treatment. We have previously reported that JCI-20679 (1), an analog of annonaceous acetogenins, shows potent antitumor activity against glioblastomas. However, the synthesis of 1 requires 23 steps, including 16 steps for the preparation of a tetrahydrofuran (THF) moiety. This study reports the design and synthesis of 11 analogs with a triethylene glycol moiety in place of the THF moiety in 1. Among these, the analog 2k with an n-decyl chain exhibited potent inhibitory activity against the growth of glioblastoma stem cells by inhibiting mitochondrial function and synergistically enhancing the effect of temozolomide (TMZ). Furthermore, 2k significantly suppressed tumor growth without critical toxicity in vivo. Hence, this study presents novel potential anticancer agents and a strategy for the development of these agents that can be produced easily.

Unsupervised machine learning models reveal predictive markers of glioblastoma patient survival using white blood cell counts prior to initiating chemoradiation

Purpose

Glioblastoma is a malignant brain tumor requiring careful clinical monitoring even after primary management. Personalized medicine has suggested use of various molecular biomarkers as predictors of patient prognosis or factors utilized for clinical decision making. However, the accessibility of such molecular testing poses a constraint for various institutes requiring identification of low-cost predictive biomarkers to ensure equitable care.

Methods

We collected retrospective data from patients seen at Ohio State University, University of Mississippi, Barretos Cancer Hospital (Brazil), and FLENI (Argentina) who were managed for glioblastoma-amounting to nearly 600 patient records documented using REDCap. Patients were evaluated using an unsupervised machine learning approach comprised of dimensionality reduction and eigenvector analysis to visualize the inter-relationship of collected clinical features.

Results

We discovered that white blood cell count of a patient during baseline planning for treatment was predictive of overall survival with an over 6-month median survival difference between the upper and lower quartiles of white blood cell count. By utilizing an objective PDL-1 immunohistochemistry quantification algorithm, we were further able to identify an increase in PDL-1 expression in glioblastoma patients with high white blood cell counts.

Conclusion

These findings suggest that in a subset of glioblastoma patients the incorporation of white blood cell count and PDL-1 expression in the brain tumor biopsy as simple biomarkers predicting glioblastoma patient survival. Moreover, use of machine learning models allows us to visualize complex clinical datasets to uncover novel clinical relationships.

Radiation combined with oncolytic vaccinia virus provides pronounced antitumor efficacy and induces immune protection in an aggressive glioblastoma model

Glioblastoma (GB) is a malignant and immune-suppressed brain cancer that remains incurable despite the current standard of care. Radiotherapy is a mainstay of GB treatment, however invasive cancer cells outside the irradiated field and radioresistance preclude complete eradication of GB cells. Oncolytic virus therapy harnesses tumor-selective viruses to spread through and destroy tumors while stimulating antitumor immune responses, and thus has potential for use following radiotherapy. We demonstrate that oncolytic ΔF4LΔJ2R vaccinia virus (VACV) replicates in and induces cytotoxicity of irradiated brain tumor initiating cells in vitro. Importantly, a single 10 Gy dose of radiation combined with ΔF4LΔJ2R VACV produced considerably superior anticancer effects relative to either monotherapy when treating immune-competent orthotopic CT2A-luc mouse models-significantly extending survival and curing the majority of mice. Mice cured by the combination displayed significantly increased survival relative to naïve age-matched controls following intracranial tumor challenge, with some complete rejections. Further, the combination therapy was associated with an increased ratio of CD8⁺ effector T cells to regulatory T cells compared to either monotherapy. This study validates the use of radiation with an oncolytic ΔF4LΔJ2R VACV to improve treatment of this malignant brain cancer.

Recent advances and future challenges of tumor vaccination therapy for recurrent glioblastoma

Glioblastoma (GBM) is the most malignant CNS tumor with a highest incidence rate, and most patients would undergo a recurrence. Recurrent GBM (rGBM) shows an increasing resistance to chemotherapy and radiotherapy, leading to a significantly poorer prognosis and the urgent need for novel treatments. Immunotherapy, a rapidly developing anti-tumor therapy in recent years, has shown its potential value in rGBM. Recent studies on PD-1 immunotherapy and CAR-T therapy have shown some efficacy, but the outcome was not as expected. Tumor vaccination is the oldest approach of immunotherapies, which has returned to the research focus because of the failure of other strategies and subversive understanding of CNS. The isolation effect of blood brain barrier and the immunosuppressive cell infiltration could lead to resistance existing in all phases of the anti-tumor immune response, where novel tumor vaccines have been designed to overcome these problems through new tumor antigenic targets and regulatory of the systematic immune response. In this review, the immunological characteristics of CNS and GBM would be discussed and summarized, as well as the mechanism of each novel tumor vaccine for rGBM. And through the review of completed early-phase studies and ongoing large-scale phase III clinical trials, evaluation could be conducted for potential immune response, biosecurity and initial clinical outcome, which further draw a panorama of this vital research field and provide some deep thoughts for the prospective tendency of vaccination strategy. Video Abstract.

Highlighted Advances in Therapies for Difficult-To-Treat Brain Tumours Such as Glioblastoma

Glioblastoma multiforme (GBM) remains a challenging disease, as it is the most common and deadly brain tumour in adults and has no curative solution and an overall short survival time. This incurability and short survival time means that, despite its rarity (average incidence of 3.2 per 100,000 persons), there has been an increased effort to try to treat this disease. Standard of care in newly diagnosed glioblastoma is maximal tumour resection followed by initial concomitant radiotherapy and temozolomide (TMZ) and then further chemotherapy with TMZ. Imaging techniques are key not only to diagnose the extent of the affected tissue but also for surgery planning and even for intraoperative use. Eligible patients may combine TMZ with tumour treating fields (TTF) therapy, which delivers low-intensity and intermediate-frequency electric fields to arrest tumour growth. Nonetheless, the blood–brain barrier (BBB) and systemic side effects are obstacles to successful chemotherapy in GBM; thus, more targeted, custom therapies such as immunotherapy and nanotechnological drug delivery systems have been undergoing research with varying degrees of success. This review proposes an overview of the pathophysiology, possible treatments, and the most (not all) representative examples of the latest advancements.

Possible regulation of ganglioside GD3 synthase gene expression with DNA methylation in human glioma cells

Gangliosides are expressed in nervous systems and some neuroectoderm-derived tumors at high levels and play pivotal roles. However, mechanisms for the regulation of glycosyltransferase genes responsible for the ganglioside synthesis are not well understood. In this study, we analyzed DNA methylation patterns of promoter regions of GD3 synthase (ST8SIA1) as well as mRNA levels and ganglioside expression using human glioma cell lines. Among 5 cell lines examined, 4 lines showed changes in the expression levels of related genes after treatment with 5-aza-dC. LN319 showed up-regulation of St8sia1 and increased b-series gangliosides after 5-aza-dC treatment, and an astrocytoma cell line, AS showed high expression of ST8SIA1 and b-series gangliosides persistently before and after 5-Aza-2'-deoxycytidine treatment. Using these 2 cell lines, DNA methylation patterns of the promoter regions of the gene were analyzed by bisulfite-sequencing. Consequently, 2 regions that were methylated before 5-Aza-2'-deoxycytidine treatment were demethylated in LN319 after the treatment, while those regions were persistently demethylated in AS. These 2 regions corresponded with sites defined as promoter regions by Luciferase assay. Taken together, it was suggested that ST8SIA1 gene is regulated by DNA methylation at the promoter regions, leading to the regulation of tumor phenotypes.

Anticancer and antimicrobial activity of new copper (II) complexes

In this study, three new organic ligands N'-(benzylidene)-6-chloropyrazine-2-carbohydrazonamide (L₁), 6-chloro-N'-(4-nitrobenzylidene)picolinohydrazonamide(L₂), and N'-(benzylidene)-4-chloropicolinohydrazonamide (L₃) and three copper coordination compounds (Cu(L₁)Cl₂, Cu(L₂)Cl₂ and Cu(L₃)Cl₂) based on them were synthesized. All obtained compounds were characterized using appropriate analytical techniques: elemental analysis (EA), thermogravimetric analysis (TG-DTG), Fourier transform infrared spectroscopy (FTIR) and flame-atomic absorption spectrometry (F-AAS). These methods of physicochemical analyses helped to assume that the complexation in three cases proceeds in a bidentate manner. The X-ray investigation confirmed the synthesis pathway and molecular structures for L₁ and L₃ ligands. The antimicrobial activity of the obtained compounds was then comprehensively investigated, where Cu(L₃)Cl₂ showed the strongest antibacterial properties against all tested bacteria (Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli). LN229 human glioma cells and BJ human normal fibroblasts cells were treated with tested compounds and their cytotoxicity was evaluated with MTT test. The effect of complexing on antitumor activity has been investigated. The ligand L₁ and its complex showed similar activity against normal cells while complexation increases toxicity against cancer cells in concentrations of 50 and 100 μM. For the one pair of ligand/complex compounds the apoptosis detection, cell cycle analysis and gene expression analysis (qRT-PCR) were performed. Cu(L₁)Cl₂ showed the stronger toxic effect in comparison with L₁ due to the population of early apoptotic cells which revealed metabolic activity in MTT assay.

Expression and Prognostic Value of CD80 and CD86 in the Tumor Microenvironment of Newly Diagnosed Glioblastoma

BACKGROUND

Strategies to modulate the tumor microenvironment (TME) have opened new therapeutic avenues with dramatic yet heterogeneous intertumoral efficacy in multiple cancers, including glioblastomas (GBMs). Therefore, investigating molecular actors of TME may help understand the interactions between tumor cells and TME. Immune checkpoint proteins such as a Cluster of Differentiation 80 (CD80) and CD86 are expressed on the surface of tumor cells and infiltrative tumor lymphocytes. However, their expression and prognostic value in GBM microenvironment are still unclear.

METHODS

In this study, we investigated, in a retrospective local discovery cohort and a validation TCGA dataset, expression of CD80 and CD86 at mRNA level and their prognostic significance in response to standard of care. Furthermore, CD80 and CD86 at the protein level were investigated in the discovery cohort.

RESULTS

Both CD80 and CD86 are expressed heterogeneously in the TME at mRNA and protein levels. In a univariate analysis, the mRNA expression of CD80 and CD86 was not significantly correlated with OS in both local OncoNeuroTek dataset and TCGA datasets. CD80 and CD86 mRNA high expression was significantly associated with shorter progression free survival (PFS) (p < 0.05). These findings were validated using the TCGA cohort; higher CD80 and CD86 expressions were correlated with shorter PFS (p < 0.05). In multivariate analysis, CD86 mRNA expression was an independent prognostic factor for PFS in the TCGA dataset only (p < 0.05).

CONCLUSION

CD86 could be used as a potential biomarker for the prognosis of GBM patients treated with immunotherapy; however, additional studies are needed to validate these findings.

A Novel Molecular Classification Method for Glioblastoma Based on Tumor Cell Differentiation Trajectories

The latest 2021 WHO classification redefines glioblastoma (GBM) as the hierarchical reporting standard by eliminating glioblastoma, IDH-mutant and only retaining the tumor entity of "glioblastoma, IDH-wild type." Knowing that subclassification of tumors based on molecular features is supposed to facilitate the therapeutic choice and increase the response rate in cancer patients, it is necessary to carry out molecular classification of the newly defined GBM. Although differentiation trajectory inference based on single-cell sequencing (scRNA-seq) data holds great promise for identifying cell heterogeneity, it has not been used in the study of GBM molecular classification. Single-cell transcriptome sequencing data from 10 GBM samples were used to identify molecular classification based on differentiation trajectories. The expressions of identified features were validated by public bulk RNA-sequencing data. Clinical feasibility of the classification system was examined in tissue samples by immunohistochemical (IHC) staining and immunofluorescence, and their clinical significance was investigated in public cohorts and clinical samples with complete clinical follow-up information. By analyzing scRNA-seq data of 10 GBM samples, four differentiation trajectories from the glioblastoma stem cell-like (GSCL) cluster were identified, based on which malignant cells were classified into five characteristic subclusters. Each cluster exhibited different potential drug sensitivities, pathways, functions, and transcriptional modules. The classification model was further examined in TCGA and CGGA datasets. According to the different abundance of five characteristic cell clusters, the patients were classified into five groups which we named Ac-G, Class-G, Neo-G, Opc-G, and Undiff-G groups. It was found that the Undiff-G group exhibited the worst overall survival (OS) in both TCGA and CGGA cohorts. In addition, the classification model was verified by IHC staining in 137 GBM samples to further clarify the difference in OS between the five groups. Furthermore, the novel biomarkers of glioblastoma stem cells (GSCs) were also described. In summary, we identified five classifications of GBM and found that they exhibited distinct drug sensitivities and different prognoses, suggesting that the new grouping system may be able to provide important prognostic information and have certain guiding significance for the treatment of GBM, and identified the GSCL cluster in GBM tissues and described its characteristic program, which may help develop new potential therapeutic targets for GSCs in GBM.

CoQ10 reduces glioblastoma growth and infiltration through proteome remodeling and inhibition of angiogenesis and inflammation

PURPOSE

Most monotherapies available against glioblastoma multiforme (GBM) target individual hallmarks of this aggressive brain tumor with minimal success. In this article, we propose a therapeutic strategy using coenzyme Q10 (CoQ10) as a pleiotropic factor that crosses the blood-brain barrier and accumulates in cell membranes acting as an antioxidant, and in mitochondrial membranes as a regulator of cell bioenergetics and gene expression.

METHODS

Xenografts of U251 cells in nu/nu mice were used to assay tumor growth, hypoxia, angiogenesis, and inflammation. An orthotopic model was used to explore microglial infiltration, tumor growth, and invasion into the brain parenchyma. Cell proliferation, migration, invasion, proteome remodeling, and secretome were assayed in vitro. Conditioned media were used to assay angiogenesis, monocyte chemoattraction, and differentiation into macrophages in vitro.

RESULTS

CoQ10 treatment decreased tumor volume in xenografts and orthotopic models, although its effect on tumor cell proliferation was not direct. Tumors from mice treated with CoQ10 were less hypoxic and vascularized, having less infiltration from inflammatory cells. Treatment-induced downregulation of HIF-1α and NF-kB led to a complete remodeling of the tumor cells proteome and secretome, impacting angiogenesis, monocyte infiltration, and their differentiation into macrophages. Besides, tumor cell migration and invasion were drastically restricted by mechanisms involving modulation of the actin cytoskeleton and downregulation of matrix metalloproteases (MMPs).

CONCLUSIONS

CoQ10 has a pleiotropic effect on GBM growth, targeting several hallmarks simultaneously. Thus, its integration into current treatments of this fatal disease should be considered.

Dual Immunostimulatory Pathway Agonism through a Synthetic Nanocarrier Triggers Robust Anti-Tumor Immunity in Murine Glioblastoma

Myeloid cells are abundant, create a highly immunosuppressive environment in glioblastoma (GBM), and thus contribute to poor immunotherapy responses. Based on the hypothesis that small molecules can be used to stimulate myeloid cells to elicit anti-tumor effector functions, a synthetic nanoparticle approach is developed to deliver dual NF-kB pathway-inducing agents into these cells via systemic administration. Synthetic, cyclodextrin-adjuvant nanoconstructs (CANDI) with high affinity for tumor-associated myeloid cells are dually loaded with a TLR7 and 8 (Toll-like receptor, 7 and 8) agonist (R848) and a cIAP (cellular inhibitor of apoptosis protein) inhibitor (LCL-161) to dually activate these myeloid cells. Here CANDI is shown to: i) readily enter the GBM tumor microenvironment (TME) and accumulate at high concentrations, ii) is taken up by tumor-associated myeloid cells, iii) potently synergize payloads compared to monotherapy, iv) activate myeloid cells, v) fosters a "hot" TME with high levels of T effector cells, and vi) controls the growth of murine GBM as mono- and combination therapies with anti-PD1. Multi-pathway targeted myeloid stimulation via the CANDI platform can efficiently drive anti-tumor immunity in GBM.

Signaling pathways in brain tumors and therapeutic interventions

Brain tumors, although rare, contribute to distinct mortality and morbidity at all ages. Although there are few therapeutic options for brain tumors, enhanced biological understanding and unexampled innovations in targeted therapies and immunotherapies have considerably improved patients' prognoses. Nonetheless, the reduced response rates and unavoidable drug resistance of currently available treatment approaches have become a barrier to further improvement in brain tumor (glioma, meningioma, CNS germ cell tumors, and CNS lymphoma) treatment. Previous literature data revealed that several different signaling pathways are dysregulated in brain tumor. Importantly, a better understanding of targeting signaling pathways that influences malignant behavior of brain tumor cells might open the way for the development of novel targeted therapies. Thus, there is an urgent need for a more comprehensive understanding of the pathogenesis of these brain tumors, which might result in greater progress in therapeutic approaches. This paper began with a brief description of the epidemiology, incidence, risk factors, as well as survival of brain tumors. Next, the major signaling pathways underlying these brain tumors' pathogenesis and current progress in therapies, including clinical trials, targeted therapies, immunotherapies, and system therapies, have been systemically reviewed and discussed. Finally, future perspective and challenges of development of novel therapeutic strategies in brain tumor were emphasized.

Spectral flow cytometry identifies distinct nonneoplastic plasma extracellular vesicle phenotype in glioblastoma patients

Background

Glioblastoma (GBM) is the most common malignant brain tumor and has a poor prognosis. Imaging findings at diagnosis and in response to treatment are nonspecific. Developing noninvasive assays to augment imaging would be helpful. Plasma extracellular vesicles (EVs) are a promising biomarker source for this. Here, we develop spectral flow cytometry techniques that demonstrate differences in bulk plasma EV phenotype between GBM patients and normal donors that could serve as the basis of a liquid biopsy.

Methods

Plasma EVs were stained for EV-associated tetraspanins (CD9/CD63/CD81), markers indicating cell of origin (CD11b/CD31/CD41a/CD45), and actin/phalloidin (to exclude cell debris). EVs were analyzed using spectral flow cytometry. Multiparametric analysis using t-distributed stochastic neighbor embedding (t-SNE) and self-organizing maps on flow cytometry data (FlowSOM) was performed comparing GBM and normal donor (ND) plasma EVs.

Results

Size exclusion chromatography plus spectral-based flow cytometer threshold settings enriched plasma EVs while minimizing background noise. GBM patients had increased CD9+, CD63+, CD81+, and myeloid-derived (CD11b+) EVs. Multiparametric analysis demonstrated distinct surface marker expression profiles in GBM plasma EVs compared to ND EVs. Fifteen plasma EV sub-populations differing in size and surface marker expression were identified, six enriched in GBM patients and two in normal donors.

Conclusions

Multiparametric analysis demonstrates that GBM patients have a distinct nonneoplastic plasma EV phenotype compared to ND. This simple rapid analysis can be performed without purifying tumor EVs and may serve as the basis of a liquid biopsy.

Recent oncolytic virotherapy clinical trials outline a roadmap for the treatment of high-grade glioma

Adult and pediatric high-grade gliomas (HGGs) are aggressive cancers of the central nervous system that confer dismal clinical prognoses. Standard radiation and chemotherapy have demonstrated only limited efficacy in HGGs, motivating the accelerated investigation of novel modalities such as oncolytic virus (OV) therapies. OV centered therapies work through a mixed mechanism centered on oncolysis and the stimulation of an antitumor immune response. Three recent clinical trials utilizing herpes simplex virus-1 and adenovirus-based oncolytic virotherapy demonstrated not only the safety and efficacy of OVs but also novel dosing strategies that augment OV response potential. Considering these recent trials, herein we present a roadmap for future clinical trials of oncolytic immunovirotherapy in both adult and pediatric HGG, as well as persistent roadblocks related to the assessment of OV efficacy within and between trials.

Early repeat resection for residual glioblastoma: decision-making among an international cohort of neurosurgeons

OBJECTIVE

The importance of extent of resection (EOR) in glioblastoma (GBM) has been thoroughly demonstrated. However, few studies have explored the practices and benefits of early repeat resection (ERR) when residual tumor deemed resectable is unintentionally left after an initial resection, and the survival benefit of ERR is still unknown. Herein, the authors aimed to internationally survey current practices regarding ERR and to analyze differences based on geographic location and practice setting.

METHODS

The authors distributed a survey to the American Association of Neurological Surgeons and Congress of Neurological Surgeons Tumor Section, Society of British Neurological Surgeons, European Association of Neurosurgical Society, and Latin American Federation of Neurosurgical Societies. Neurosurgeons responded to questions about their training, practice setting, and current ERR practices. They also reported the EOR threshold below which they would pursue ERR and their likelihood of performing ERR using a Likert scale of 1-5 (5 being the most likely) in two sets of 5 cases, the first set for a patient's initial hospitalization and the second for a referred patient who had undergone resection elsewhere. The resection likelihood index for each respondent was calculated as the mean Likert score across all cases.

RESULTS

Overall, 180 neurosurgeons from 25 countries responded to the survey. Neurosurgeons performed ERRs very rarely in their practices (< 1% of all GBM cases), with an EOR threshold of 80.2% (75%-95%). When presented with 10 cases, the case context (initial hospitalization vs referred patient) did not significantly change the surgeon ERR likelihood, although ERR likelihood did vary significantly on the basis of tumor location (p < 0.0001). Latin American neurosurgeons were more likely to pursue ERR in the provided cases. Neurosurgeons were more likely to pursue ERR when the tumor was MGMT methylated versus unmethylated, with a resection likelihood index of 3.78 and 3.21, respectively (p = 0.004); however, there was no significant difference between IDH mutant and IDH wild-type tumors.

CONCLUSIONS

Results of this survey reveal current practices regarding ERR, but they also demonstrate the variability in how neurosurgeons approach ERR. Standardized guidelines based on future studies incorporating tumor molecular characteristics are needed to guide neurosurgeons in their decision-making on this complicated issue.

Updates in intraoperative strategies for enhancing intra-axial brain tumor control

To ensure excellent postoperative clinical outcomes while preserving critical neurologic function, neurosurgeons who manage patients with intra-axial brain tumors can use intraoperative technologies and tools to achieve maximal safe resection. Neurosurgical oncology revolves around safe and optimal extent of resection, which further dictates subsequent treatment regimens and patient outcomes. Various methods can be adapted for treating both primary and secondary intra-axial brain lesions. We present a review of recent advances and published research centered on different innovative tools and techniques, including fluorescence-guided surgery, new methods of drug delivery, and minimally invasive procedural options.

Optimization of Tumor Targeting Gold Nanoparticles for Glioblastoma Applications

Glioblastoma brain tumors represent an aggressive form of gliomas that is hallmarked by being extremely invasive and aggressive due to intra and inter-tumoral heterogeneity. This complex tumor microenvironment makes even the newer advancements in glioblastoma treatment less effective long term. In developing newer treatment technologies against glioblastoma, one should tailor the treatment to the tumor microenvironment, thus allowing for a more robust and sustained anti-glioblastoma effect. Here, we present a novel gold nanoparticle therapy explicitly designed for bioactivity against glioblastoma representing U87MG cell lines. We employ standard conjugation techniques to create oligonucleotide-coated gold nanoparticles exhibiting strong anti-glioblastoma behavior and optimize their design to maximize bioactivity against glioblastoma. Resulting nanotherapies are therapy specific and show upwards of 75% inhibition in metabolic and proliferative activity with stark effects on cellular morphology. Ultimately, these gold nanotherapies are a good base for designing more multi-targeted approaches to fighting against glioblastoma.

Comparable Long-Term Tumor Control for Hypofractionated FLASH Versus Conventional Radiation Therapy in an Immunocompetent Rat Glioma Model

Purpose

To ensure a clinical translation of FLASH radiation therapy (FLASH-RT) for a specific tumor type, studies on tumor control and toxicity within the same biological system are needed. In this study, our objective was to evaluate tumor control and toxicity for hypofractionated FLASH-RT and conventional radiation therapy (CONV-RT) in an immunocompetent rat glioma model.

Methods and Materials

Fisher 344 rats (N = 68) were inoculated subcutaneously with NS1 glioma cells and randomized into groups (n = 9-10 per group). CONV-RT (∼8 Gy/min) or FLASH-RT (70-90 Gy/s) was administered in 3 fractions of either 8 Gy, 12.5 Gy, or 15 Gy using a 10-MeV electron beam. The maximum tumor diameter was measured weekly, and overall survival was determined until day 100. Long-term tumor control was defined as no evident tumor on day 100. Animals were evaluated for acute dermal side effects at 2 to 5 weeks after completed RT and for late dermal side effects at 3 months after initiation of treatment.

Results

Survival was significantly increased in all irradiated groups compared with control animals (P < .001). In general, irradiated tumors started to shrink at 1 week post-completed RT. In 40% (23 of 58) of the irradiated animals, long-term tumor control was achieved. Radiation-induced skin toxic effects were mild and consisted of hair loss, erythema, and dry desquamation. No severe toxic effect was observed. There was no significant difference between FLASH-RT and CONV-RT in overall survival, acute side effects, or late side effects for any of the dose levels.

Conclusions

This study shows that hypofractionated FLASH-RT results in long-term tumor control rates similar to those of CONV-RT for the treatment of large subcutaneous glioblastomas in immunocompetent rats. Neither treatment technique induced severe skin toxic effects. Consequently, no significant difference in toxicity could be resolved, suggesting that higher doses may be required to detect a FLASH sparing of skin.

Elastin-like Polypeptide Hydrogels for Tunable, Sustained Local Chemotherapy in Malignant Glioma

Glioblastoma (GBM) is a primary brain tumor that carries a dismal prognosis, which is primarily attributed to tumor recurrence after surgery and resistance to chemotherapy. Since the tumor recurrence appears near the site of surgical resection, a concept of immediate and local application of chemotherapeutic after initial tumor removal could lead to improved treatment outcome. With the ultimate goal of developing a locally-applied, injectable drug delivery vehicle for GBM treatment, we created elastin-like polypeptide (ELP) hydrogels. The ELP hydrogels can be engineered to release anti-cancer drugs over an extended period. The purpose of this study was to evaluate the biomechanical properties of ELP hydrogels, to characterize their ability to release doxorubicin over time, and to investigate, in vitro, the anti-proliferative effect of Dox-laden ELP hydrogels on GBM. Here, we present microstructural differences, swelling ratio measurements, drug release characteristics, and in vitro effects of different ELP hydrogel compositions. We found that manipulation of the ELP–collagen ratio allows for tunable drug release, that the released drug is taken up by cells, and that incubation with a small volume of ELP-Dox hydrogel drastically reduced survival and proliferation of GBM cells in vitro. These results underscore the potential of ELP hydrogels as a local delivery strategy to improve prognosis for GBM patients after tumor resection.