A Critical Overview of Targeted Therapies for Glioblastoma

Digital Pathology and Artificial Intelligence Applications in Pathology

Digital pathology is revolutionizing pathology. The introduction of digital pathology made it possible to comprehensively change the pathology diagnosis workflow, apply and develop pathological artificial intelligence (AI) models, generate pathological big data, and perform telepathology. AI algorithms, including machine learning and deep learning, are used for the detection, segmentation, registration, processing, and classification of digitized pathological images. Pathological AI algorithms can be helpfully utilized for diagnostic screening, morphometric analysis of biomarkers, the discovery of new meanings of prognosis and therapeutic response in pathological images, and improvement of diagnostic efficiency. In order to develop a successful pathological AI model, it is necessary to consider the selection of a suitable type of image for a subject, utilization of big data repositories, the setting of an effective annotation strategy, image standardization, and color normalization. This review will elaborate on the advantages and perspectives of digital pathology, AI-based approaches, the applications in pathology, and considerations and challenges in the development of pathological AI models.

“Security Dilemma”: Active Immunotherapy before Versus after Radiation Therapy Alone or Chemo-Radiotherapy for Newly Diagnosed Glioblastoma

Management of glioblastoma should be aggressive and personalised to increase the quality of life. Many new therapies, such as active immunotherapy, increase the overall survival, yet they result in complications which render the search for the optimal treatment stra-tegy challenging.

In order to answer whether the available treatment options should be administered in a specific row, we performed a literature search and meta-analysis. The results show that overall survival among the different treatment groups was equal, while the rates of complications were unequal. After surgery, when active immunotherapy was administered before radiation, radiation and chemotherapy, complication rates were lower.

For newly diagnosed glioblastoma in adults, applying active immunotherapy after total resection but before the other complementary treatment options is associated with lower complication rates.

A Tumor-Homing Peptide Platform Enhances Drug Solubility, Improves Blood-Brain Barrier Permeability and Targets Glioblastoma

Simple Summary

Glioblastoma (GBM) is a fatal and incurable brain cancer, and current treatment options have demonstrated limited success. Here, we describe the use of a dg-Bcan-Targeting-Peptide (BTP-7) that has BBB-penetrating properties and targets GBM. Conjugation of BTP-7 to an insoluble anti-cancer drug, camptothecin (CPT), improves drug solubility in aqueous solution, retains drug efficacy against patient-derived GBM stem cells (GSC), enhances BBB permeability, and enables therapeutic targeting to intracranial patient-derived GBM xenograft in mice, leading to higher toxicity in GBM cells compared to normal brain tissues and prolonged animal survival. This work demonstrates a proof-of-concept for BTP-7 as a tumor-targeting peptide for therapeutic delivery to GBM.

Abstract

Background: Glioblastoma (GBM) is the most common and deadliest malignant primary brain tumor, contributing significant morbidity and mortality among patients. As current standard-of-care demonstrates limited success, the development of new efficacious GBM therapeutics is urgently needed. Major challenges in advancing GBM chemotherapy include poor bioavailability, lack of tumor selectivity leading to undesired side effects, poor permeability across the blood–brain barrier (BBB), and extensive intratumoral heterogeneity. Methods: We have previously identified a small, soluble peptide (BTP-7) that is able to cross the BBB and target the human GBM extracellular matrix (ECM). Here, we covalently attached BTP-7 to an insoluble anti-cancer drug, camptothecin (CPT). Results: We demonstrate that conjugation of BTP-7 to CPT improves drug solubility in aqueous solution, retains drug efficacy against patient-derived GBM stem cells (GSC), enhances BBB permeability, and enables therapeutic targeting to intracranial GBM, leading to higher toxicity in GBM cells compared to normal brain tissues, and ultimately prolongs survival in mice bearing intracranial patient-derived GBM xenograft. Conclusion: BTP-7 is a new modality that opens the door to possibilities for GBM-targeted therapeutic approaches.

Antibody-Based Formats to Target Glioblastoma: Overcoming Barriers to Protein Drug Delivery

Glioblastoma (GB) is recognized as the most aggressive form of primary brain cancer. Despite advances in treatment strategies that include surgery, radiation, and chemotherapy, the median survival time (∼15 months) of patients with GB has not significantly improved. The poor prognosis of GB is also associated with a very high chance of tumor recurrence (∼90%), and current treatment measures have failed to address the complications associated with this disease. However, targeted therapies enabled through antibody engineering have shown promise in countering GB when used in combination with conventional approaches. Here, we discuss the challenges in conventional as well as future GB therapeutics and highlight some of the known advantages of using targeted biologics to overcome these impediments. We also review a broad range of potential alternative routes that could be used clinically to administer anti-GB biologics to the brain through evasion of its natural barriers.

Emerging therapies for glioblastoma: current state and future directions

Glioblastoma (GBM) is the most common high-grade primary malignant brain tumor with an extremely poor prognosis. Given the poor survival with currently approved treatments for GBM, new therapeutic strategies are urgently needed. Advances in decades of investment in basic science of glioblastoma are rapidly translated into innovative clinical trials, utilizing improved genetic and epigenetic profiling of glioblastoma as well as the brain microenvironment and immune system interactions. Following these encouraging findings, immunotherapy including immune checkpoint blockade, chimeric antigen receptor T (CAR T) cell therapy, oncolytic virotherapy, and vaccine therapy have offered new hope for improving GBM outcomes; ongoing studies are using combinatorial therapies with the aim of minimizing adverse side-effects and augmenting antitumor immune responses. In addition, techniques to overcome the blood-brain barrier (BBB) for targeted delivery are being tested in clinical trials in patients with recurrent GBM. Here, we set forth the rationales for these promising therapies in treating GBM, review the potential novel agents, the current status of preclinical and clinical trials, and discuss the challenges and future perspectives in glioblastoma immuno-oncology.

Valganciclovir as Add-on to Second-Line Therapy in Patients with Recurrent Glioblastoma

Simple Summary

Patients with glioblastoma have a dismal prognosis. The major challenge with this disease is that it recurs despite aggressive first-line therapy and rapidly becomes therapy resistant. Cytomegalovirus has been found in most glioblastoma tumors and may contribute to tumor aggressiveness. Antiviral therapy may thus represent a novel therapeutic strategy and has shown promising results in patients with newly diagnosed glioblastoma. We performed a retrospective analysis of survival data of 29 patients with recurrent glioblastoma receiving the antiviral drug valganciclovir as an add-on to second-line therapy and of 109 contemporary controls treated at our institution. Valganciclovir was well tolerated and seemed to improve survival after tumor recurrence in patients with recurrent disease both in re-operated and non-re-operated patients and in patients with unmethylated and methylated MGMT promoter status. Prospective controlled clinical studies on patients with recurrent glioblastoma are warranted to evaluate if valganciclovir treatment offers a novel therapeutic option.

Abstract

Glioblastoma invariably recurs despite aggressive and multimodal first-line treatment and no standardized second-line therapy exists. We previously reported that treatment with the antiviral drug valganciclovir as an add-on to standard therapy significantly prolonged overall survival in 102 patients with newly diagnosed glioblastoma compared to contemporary controls. Here we present the results of retrospective survival analyses including patients with glioblastoma that initiated valganciclovir therapy after recurrence. Twenty-nine patients with recurrent glioblastoma received valganciclovir as an add-on to second-line therapy at Karolinska University Hospital. Contemporary controls were 109 patients with glioblastoma who received similar second-line therapy at our institution. We retrospectively analyzed survival data of these patients. Patients with recurrent glioblastoma who received valganciclovir had longer median overall survival after recurrence than controls (12.1 vs. 7.4 months, respectively, p = 0.0028). The drug was well tolerated. Both patients who underwent re-operation and patients that were not re-operated after recurrence benefitted significantly from valganciclovir therapy. Valganciclovir prolonged survival after recurrence both in patients with an unmethylated and methylated MGMT promoter gene. Valganciclovir was safe to use and prolonged median survival after recurrence for patients with recurrent glioblastoma, re-operated or not after recurrence, and with methylated or unmethylated MGMT promoter gene.

The Proliferation of Glioblastoma Is Contributed to Kinesin Family Member 18A and Medical Data Analysis of GBM

Background: Glioblastoma (GBM) is widely known as a classical kind of malignant tumor originating in the brain with high morbidity and mortality. Targeted therapy has shown great promise in treating glioblastoma, but more promising targets, including effective therapeutic targets, remain to be identified. 18A (KIF18A) is a microtubule-based motor protein that is dysregulated and involved in the progression of multiple human cancers. However, the possible effects of KIF18A on GBM progression are still unclear.

Methods: We performed DEG analysis, medical data analysis, and network analysis to identify critical genes affecting glioma progression. We also performed immunohistochemical analysis of the KIF18A levels in 94 patients with glioblastoma and the associated surrounding tissues. Patients were divided into two groups according to the high and low expression. Using a clinical analysis, we showed the potential associations between KIF18A expression and clinical characteristics of 94 GBM patients. We then investigated the effects of KIF18A on GBM cell proliferation by colony establishment, MTT, and immune blogging. The possible effect of KIF18A on GBM tumor growth was determined in mice.

Results: We identified KIF18A as a potential gene affecting GBM progression. We further demonstrated that GBM tissues expressed KIF18A much higher, and its presentation was associated with recurrence in glioblastoma patients. We believe KIF18A promotes GBM cell proliferation.

Conclusion: We demonstrated that KIF18A could be a promising target in treating GBM.

Perspective on the Use of DNA Repair Inhibitors as a Tool for Imaging and Radionuclide Therapy of Glioblastoma

Simple Summary

The current routine treatment for glioblastoma (GB), the most lethal high-grade brain tumor in adults, aims to induce DNA damage in the tumor. However, the tumor cells might be able to repair that damage, which leads to therapy resistance. Fortunately, DNA repair defects are common in GB cells, and their survival is often based on a sole backup repair pathway. Hence, targeted drugs inhibiting essential proteins of the DNA damage response have gained momentum and are being introduced in the clinic. This review gives a perspective on the use of radiopharmaceuticals targeting DDR kinases for imaging in order to determine the DNA repair phenotype of GB, as well as for effective radionuclide therapy. Finally, four new promising radiopharmaceuticals are suggested with the potential to lead to a more personalized GB therapy.

Abstract

Despite numerous innovative treatment strategies, the treatment of glioblastoma (GB) remains challenging. With the current state-of-the-art therapy, most GB patients succumb after about a year. In the evolution of personalized medicine, targeted radionuclide therapy (TRT) is gaining momentum, for example, to stratify patients based on specific biomarkers. One of these biomarkers is deficiencies in DNA damage repair (DDR), which give rise to genomic instability and cancer initiation. However, these deficiencies also provide targets to specifically kill cancer cells following the synthetic lethality principle. This led to the increased interest in targeted drugs that inhibit essential DDR kinases (DDRi), of which multiple are undergoing clinical validation. In this review, the current status of DDRi for the treatment of GB is given for selected targets: ATM/ATR, CHK1/2, DNA-PK, and PARP. Furthermore, this review provides a perspective on the use of radiopharmaceuticals targeting these DDR kinases to (1) evaluate the DNA repair phenotype of GB before treatment decisions are made and (2) induce DNA damage via TRT. Finally, by applying in-house selection criteria and analyzing the structural characteristics of the DDRi, four drugs with the potential to become new therapeutic GB radiopharmaceuticals are suggested.

Prognostic value and immune relevancy of a combined autophagy-, apoptosis- and necrosis-related gene signature in glioblastoma

Background

Glioblastoma (GBM) is considered the most malignant and devastating intracranial tumor without effective treatment. Autophagy, apoptosis, and necrosis, three classically known cell death pathways, can provide novel clinical and immunological insights, which may assist in designing personalized therapeutics. In this study, we developed and validated an effective signature based on autophagy-, apoptosis- and necrosis-related genes for prognostic implications in GBM patients.

Methods

Variations in the expression of genes involved in autophagy, apoptosis and necrosis were explored in 518 GBM patients from The Cancer Genome Atlas (TCGA) database. Univariate Cox analysis, least absolute shrinkage and selection operator (LASSO) analysis, and multivariate Cox analysis were performed to construct a combined prognostic signature. Kaplan–Meier survival, receiver-operating characteristic (ROC) curves and Cox regression analyses based on overall survival (OS) and progression-free survival (PFS) were conducted to estimate the independent prognostic performance of the gene signature. The Chinese Glioma Genome Atlas (CGGA) dataset was used for external validation. Finally, we investigated the differences in the immune microenvironment between different prognostic groups and predicted potential compounds targeting each group.

Results

A 16-gene cell death index (CDI) was established. Patients were clustered into either the high risk or the low risk groups according to the CDI score, and those in the low risk group presented significantly longer OS and PFS than the high CDI group. ROC curves demonstrated outstanding performance of the gene signature in both the training and validation groups. Furthermore, immune cell analysis identified higher infiltration of neutrophils, macrophages, Treg, T helper cells, and aDCs, and lower infiltration of B cells in the high CDI group. Interestingly, this group also showed lower expression levels of immune checkpoint molecules PDCD1 and CD200, and higher expression levels of PDCD1LG2, CD86, CD48 and IDO1.

Conclusion

Our study proposes that the CDI signature can be utilized as a prognostic predictor and may guide patients’ selection for preferential use of immunotherapy in GBM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09328-3.

Advancements, Challenges, and Future Directions in Tackling Glioblastoma Resistance to Small Kinase Inhibitors

Simple Summary

Drug resistance is a major issue in brain tumor therapy. Despite novel promising therapeutic approaches, glioblastoma (GBM) remains refractory in showing beneficial responses to anticancer agents, as demonstrated by the failure in clinical trials of small kinase inhibitors. One of the reasons may lie in the development of different types of drug resistance mechanisms derived from the intrinsic heterogeneous nature of GBM. Obtaining insights into these mechanisms could improve the management of the clinical intervention and monitoring. Such insights could be achieved with the improvement of preclinical in vitro models for studying drug resistance.

Abstract

Despite clinical intervention, glioblastoma (GBM) remains the deadliest brain tumor in adults. Its incurability is partly related to the establishment of drug resistance, both to standard and novel treatments. In fact, even though small kinase inhibitors have changed the standard clinical practice for several solid cancers, in GBM, they did not fulfill this promise. Drug resistance is thought to arise from the heterogeneity of GBM, which leads the development of several different mechanisms. A better understanding of the evolution and characteristics of drug resistance is of utmost importance to improve the current clinical practice. Therefore, the development of clinically relevant preclinical in vitro models which allow careful dissection of these processes is crucial to gain insights that can be translated to improved therapeutic approaches. In this review, we first discuss the heterogeneity of GBM, which is reflected in the development of several resistance mechanisms. In particular, we address the potential role of drug resistance mechanisms in the failure of small kinase inhibitors in clinical trials. Finally, we discuss strategies to overcome therapy resistance, particularly focusing on the importance of developing in vitro models, and the possible approaches that could be applied to the clinic to manage drug resistance.

Use of FLOSEAL ® as a scaffold and its impact on induced neural stem cell phenotype, persistence, and efficacy

Induced neural stem cells (iNSCs) have emerged as a promising therapeutic platform for glioblastoma (GBM). iNSCs have the innate ability to home to tumor foci, making them ideal carriers for antitumor payloads. However, the in vivo persistence of iNSCs limits their therapeutic potential. We hypothesized that by encapsulating iNSCs in the FDA‐approved, hemostatic matrix FLOSEAL®, we could increase their persistence and, as a result, therapeutic durability. Encapsulated iNSCs persisted for 95 days, whereas iNSCs injected into the brain parenchyma persisted only 2 weeks in mice. Two orthotopic GBM tumor models were used to test the efficacy of encapsulated iNSCs. In the GBM8 tumor model, mice that received therapeutic iNSCs encapsulated in FLOSEAL® survived 30 to 60 days longer than mice that received nonencapsulated cells. However, the U87 tumor model showed no significant differences in survival between these two groups, likely due to the more solid and dense nature of the tumor. Interestingly, the interaction of iNSCs with FLOSEAL® appears to downregulate some markers of proliferation, anti‐apoptosis, migration, and therapy which could also play a role in treatment efficacy and durability. Our results demonstrate that while FLOSEAL® significantly improves iNSC persistence, this alone is insufficient to enhance therapeutic durability.

FCGBP Is a Prognostic Biomarker and Associated With Immune Infiltration in Glioma

The Fc Fragment of IgG Binding Protein (FCGBP) has been proven to participate in intestinal tumor immunity. However, the biological role of FCGBP has remained unclear in glioma. The differential expression of FCGBP was explored by Oncomine and GEPIA databases. The effect of FCGBP on prognosis was analyzed via Kaplan–Meier plotter and GEPIA. The Tumor Immune Estimation Resource (TIMER) tool was used to determine the correlations of FCGBP expression with tumor immune infiltration. Firstly, FCGBP was highly expressed in glioma and correlated with a worse prognosis. Gene Ontology (GO) and KEGG pathway enrichment analyses revealed that the differentially expressed genes (DEGs) and co-expression genes of FCGBP were mainly involved in the immune response. Furthermore, FCGBP expression was positively associated with multiple immune cells infiltrates as well as the expression levels of multiple immune markers in glioma. FCGBP co-expression networks mostly participated in the regulation of immune response. Finally, immunohistochemistry (IHC) assays were conducted to explore the expression of FCGBP, PD-L1, CCL2 and CD8 in glioma and correlations between them. We found that PDL1 and FCGBP were synchronously upregulated in glioma tissues. These findings revealed a new mechanism by which FCGBP participates in the immune tolerance of glioma, and implied the potential of FCGBP as a therapeutic target or predictive marker for patients.

A glutathione responsive nanocarrier based on viologen resorcinarene cavitand and 1-allylthymine

A glutathione-sensitive nanocarrier for doxorubicin to improve cellular penetration and selective cytotoxic effects on T98G human glioblastoma cells.

New phase therapeutic pursuits for targeted drug delivery in glioblastoma multiforme

Glioblastoma multiforme (GBM) is known as the most aggressive and prevalent brain tumor with a high mortality rate. It is reported in people who are as young as 10 years old to as old as over 70 years old, exhibiting inter and intra tumor heterogeneity. There are several genomic and proteomic investigations that have been performed to find the unexplored potential targets of the drug against GBM. Therefore, certain effective targets have been taken to further validate the studies embarking on the robustness in the field of medicinal chemistry followed by testing in clinical trials. Also, The Cancer Genome Atlas (TCGA) project has identified certain overexpressed targets involved in the pathogenesis of GBM in three major pathways, i.e., tumor protein 53 (p53), retinoblastoma (RB), and receptor tyrosine kinase (RTK)/rat sarcoma virus (Ras)/phosphoinositide 3-kinase (PI3K) pathways. This review focuses on the compilation of recent developments in the fight against GBM thus, directing future research into the elucidation of pathogenesis and potential cure for GBM. Also, it highlights the potential biomarkers that have undergone extensive research and have promising prognostic and predictive values. Additionally, this manuscript analyses the advent of gene therapy and immunotherapy, unlocking the way to consider treatment approaches other than, or in addition to, conventional chemo-radiation therapies. This review study encompasses all the relevant research studies associated with the pathophysiology, occurrence, diagnostic tools, and therapeutic intervention for GBM. It highlights the evolution of various therapeutic perspectives against GBM from the most conventional form of radiotherapy to the recent advancement of gene/cell/immune therapy. Further, the review focuses on various targeted therapies for GBM including chemotherapy sensitization, radiotherapy, nanoparticles based, immunotherapy, cell therapy, and gene therapy which would offer a comprehensive account for exploring several facets related to GBM prognostics.

LncRNA HLA-F-AS1 Enhances the Migration, Invasion and Apoptosis of Glioblastoma Cells by Targeting lncRNA MEG3

Background

Previous studies revealed the oncogenic role of long non-coding RNA (lncRNA) HLA-F-AS1 in colon cancer and breast cancer, while its role in other cancers is unclear. We predicted the direct interaction between HLA-F-AS1 and MEG3, which is a tumor suppressor lncRNA. We then assessed the interaction between HLA-F-AS1 and MEG3 in glioblastoma (GBM).

Methods

The expression levels of HLA-F-AS1 and MEG3 in GBM and paired non-tumor tissues from 60 GBM patients were analyzed by RT-qPCR. Overexpression of HLA-F-AS1 and MEG3 was achieved in GBM cells to explore the interaction between them. The direct interaction between them was confirmed by RNA pull-down assay. The roles of HLA-F-AS1 and MEG3 in cell invasion, migration and apoptosis were explored by Transwell assays and cell apoptosis assay.

Results

HLA-F-AS1 was highly expressed, and MEG3 was downregulated in GBM. Overexpression of HLA-F-AS1 reduced the expression levels of MEG3 while overexpression of MEG3 did not alter the expression of HLA-F-AS1. HLA-F-AS1 increased cell migration and invasion, but decreased cell apoptosis. MEG3 played opposite roles and reduced the effects of HLA-F-AS1 on cell behaviors.

Conclusion

HLA-F-AS1 may sponge MEG3 in GBM cells to promote cell invasion and migration, and to suppress cell apoptosis.

Recent developments in drug delivery strategies for targeting DNA damage response in glioblastoma

Glioblastoma is the most frequent and malignant brain tumor. The median survival for this disease is approximately 15 months, and despite all the available treatment strategies employed, it remains an incurable disease. Preclinical and clinical research have shown that the resistance process related to DNA damage repair pathways, glioma stem cells, blood-brain barrier selectivity, and dose-limiting toxicity of systemic treatment leads to poor clinical outcomes. In this context, the advent of drug delivery systems associated with localized treatment seems to be a promising and versatile alternative to overcome the failure of the current treatment approaches. In order to bypass therapeutic tumor resistance mechanisms, more effective combinatorial therapies should be identified, such as the use of cytotoxic drugs combined with the inhibition of DNA damage response (DDR)-related targets. Additionally, critical reasoning about the delivery approach and administration route in brain tumors treatment innovation is essential. The outcomes of future experimental studies regarding the association of delivery systems, alternative treatment routes, and DDR targets are expected to lead to the development of refined therapeutic interventions. Novel therapeutic approaches could improve the life's quality of glioblastoma patients and increase their survival rate.

Safety and tolerability of asunercept plus standard radiotherapy/temozolomide in Asian patients with newly-diagnosed glioblastoma: a phase I study

Asunercept (company code APG101 [Apogenix AG]; company code CAN008 [CANbridge Pharmaceuticals]) is a novel glycosylated fusion protein that has shown promising effectiveness in glioblastoma. This Phase I study was initiated to evaluate the tolerability and safety of asunercept in combination with standard radiotherapy and temozolomide (RT/TMZ) in Asian patients with newly diagnosed glioblastoma. This was the Phase I portion of a Phase I/II open label, multicenter trial of asunercept plus standard RT/TMZ. Adults with newly-diagnosed glioblastoma received surgical resection followed by standard RT/TMZ plus asunercept 200 mg/week (Cohort 1) or 400 mg/week (Cohort 2) by 30-min IV infusion. The primary endpoint was the safety and tolerability of asunercept during concurrent asunercept and RT/TMZ; dose-limiting toxicities were observed for each dose. Secondary endpoints included pharmacokinetics (PK) and 6-month progression-free survival (PFS6). All patients (Cohort 1, n = 3; Cohort 2, n = 7) completed ≥ 7 weeks of asunercept treatment. No DLTs were experienced. Only one possibly treatment-related treatment emergent adverse event (TEAE), Grade 1 gingival swelling, was observed. No Grade > 3 TEAEs were reported and no TEAE led to treatment discontinuation. Systemic asunercept exposure increased proportionally with dose and showed low inter-patient variability. The PFS6 rate was 33.3% and 57.1% for patients in Cohort 1 and 2, respectively. Patients in Cohort 2 maintained a PFS rate of 57.1% at Month 12. Adding asunercept to standard RT/TMZ was safe and well tolerated in patients with newly-diagnosed glioblastoma and 400 mg/week resulted in encouraging efficacy.

Trial registration NCT02853565, August 3, 2016.

ssDNA nanotubes for selective targeting of glioblastoma and delivery of doxorubicin for enhanced survival

Effective treatment of glioblastoma remains a daunting challenge. One of the major hurdles in the development of therapeutics is their inability to cross the blood-brain tumor barrier (BBTB). Local delivery is an alternative approach that can still suffer from toxicity in the absence of target selectivity. Here, we show that nanotubes formed from self-assembly of ssDNA-amphiphiles are stable in serum and nucleases. After bilateral brain injections, nanotubes show preferential retention by tumors compared to normal brain and are taken up by glioblastoma cells through scavenger receptor binding and macropinocytosis. After intravenous injection, they cross the BBTB and internalize in glioblastoma cells. In a minimal residual disease model, local delivery of doxorubicin showed signs of toxicity in the spleen and liver. In contrast, delivery of doxorubicin by the nanotubes resulted in no systemic toxicity and enhanced mouse survival. Our results demonstrate that ssDNA nanotubes are a promising drug delivery vehicle to glioblastoma.

GRPEL2 Knockdown Exerts Redox Regulation in Glioblastoma

Malignant brain tumors are responsible for catastrophic morbidity and mortality globally. Among them, glioblastoma multiforme (GBM) bears the worst prognosis. The GrpE-like 2 homolog (GRPEL2) plays a crucial role in regulating mitochondrial protein import and redox homeostasis. However, the role of GRPEL2 in human glioblastoma has yet to be clarified. In this study, we investigated the function of GRPEL2 in glioma. Based on bioinformatics analyses from the Cancer Gene Atlas (TCGA) and the Chinese Glioma Genome Atlas (CGGA), we inferred that GRPEL2 expression positively correlates with WHO tumor grade (p < 0.001), IDH mutation status (p < 0.001), oligodendroglial differentiation (p < 0.001), and overall survival (p < 0.001) in glioma datasets. Functional validation in LN229 and GBM8401 GBM cells showed that GRPEL2 knockdown efficiently inhibited cellular proliferation. Moreover, GRPEL2 suppression induced cell cycle arrest at the sub-G1 phase. Furthermore, GRPEL2 silencing decreased intracellular reactive oxygen species (ROS) without impending mitochondria membrane potential. The cellular oxidative respiration measured with a Seahorse XFp analyzer exhibited a reduction of the oxygen consumption rate (OCR) in GBM cells by siGRPEL2, which subsequently enhanced autophagy and senescence in glioblastoma cells. Taken together, GRPEL2 is a novel redox regulator of mitochondria bioenergetics and a potential target for treating GBM in the future.

Enhanced Anticancer Response of Curcumin- and Piperine-Loaded Lignin-g-p (NIPAM-co-DMAEMA) Gold Nanogels against U-251 MG Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is the most aggressive and commonly diagnosed brain cancer and is highly resistant to routine chemotherapeutic drugs. The present study involves the synthesis of Lignin-g-p (NIPAM-co-DMAEMA) gold nanogel, loaded with curcumin and piperine, to treat GBM. The ongoing study has the application potential to (1) overcome the limitations of drugs biodistribution, (2) enhance the toxicity of anticancer drugs against GBM, and (3) identify the drugs uptake pathway. Atom transfer radical polymerization was used to synthesize the Lignin-g-PNIPAM network, crosslinked with the gold nanoparticles (GNPs) to self-assemble into nanogels. The size distribution and morphological analysis confirmed that the drug-loaded gold nanogels are spherical and exist in the size of 180 nm. The single and combinatorial toxicity effects of curcumin- and piperine-loaded Lignin-g-p (NIPAM-co-DMAEMA) gold nanogels were studied against U-251 MG GBM cells. A cytotoxicity analysis displayed anticancer properties. IC₅₀ of curcumin- and piperine-loaded gold nanogels were recorded at 30 μM and 35 μM, respectively. Immunostaining and Western blot analysis confirmed the protein expression of caspase-3 and cleaved caspase-3 in cells treated with drug-loaded nanogels. Kinetic drug release revealed 86% release of hybrid curcumin–piperine from gold nanogel after 250 min at pH 4. Atomic absorption spectroscopic analysis confirmed that the drug-loaded nanogels have better internalization or association with the cancer cells than the GNPs or nano-gels alone. Morphological studies further confirmed that the curcumin and piperine nanogels penetrate the cells via endocytic pathways and induce caspase-3-related apoptosis. The experimental evidence shows the enhanced properties of combinatorial curcumin–piperine gold nanogels (IC50: 21 μM) to overcome the limitations of conventional chemotherapeutic treatments of glioma cells.

Precision Neurosurgery: A Path Forward

Since the inception of their profession, neurosurgeons have defined themselves as physicians with a surgical practice. Throughout time, neurosurgery has always taken advantage of technological advances to provide better and safer care for patients. In the ongoing precision medicine surge that drives patient-centric healthcare, neurosurgery strives to effectively embrace the era of data-driven medicine. Neuro-oncology best illustrates this convergence between surgery and precision medicine with the advent of molecular profiling, imaging and data analytics. This convenient convergence paves the way for new preventive, diagnostic, prognostic and targeted therapeutic perspectives. The prominent advances in healthcare and big data forcefully challenge the medical community to deeply rethink current and future medical practice. This work provides a historical perspective on neurosurgery. It also discusses the impact of the conceptual shift of precision medicine on neurosurgery through the lens of neuro-oncology.

Glioma-Targeted Therapeutics: Computer-Aided Drug Design Prospective

Amongst the several types of brain cancers known to humankind, glioma is one of the most severe and life-threatening types of cancer, comprising 40% of all primary brain tumors. Recent reports have shown the incident rate of gliomas to be 6 per 100,000 individuals per year globally. Despite the various therapeutics used in the treatment of glioma, patient survival rate remains at a median of 15 months after undergoing first-line treatment including surgery, radiation, and chemotherapy with Temozolomide. As such, the discovery of newer and more effective therapeutic agents is imperative for patient survival rate. The advent of computer-aided drug design in the development of drug discovery has emerged as a powerful means to ascertain potential hit compounds with distinctively high therapeutic effectiveness against glioma. This review encompasses the recent advances of bio-computational in-silico modeling that have elicited the discovery of small molecule inhibitors and/or drugs against various therapeutic targets in glioma. The relevant information provided in this report will assist researchers, especially in the drug design domains, to develop more effective therapeutics against this global disease.

A systematic review and meta-analysis of fluorescent-guided resection and therapy-based photodynamics on the survival of patients with glioma

Glioma is the most common primary central nervous system tumor; many methods are currently being used to research and treat glioma. In recent years, fluorescent-guided resection (FGR) and photodynamic therapy (PDT) have become hot spots in the treatment of glioma. Based on the existing literatures regarding the FGR enhancing resection rate and regarding efficacy of PDT for the treatment of glioma, this paper made a systematic review of FGR for gross total resection of patients and the PDT for the survival of patients with glioma. Meta-analysis of eligible studies was performed to derive precise estimation of PDT on the prognosis of patients with glioma by searching all related literatures in PubMed, EMBASE, Cochrane, and Web of Science databases, and further to evaluate (GTR) under FGR and the efficacy of PDT therapy, including 1-year and 2-year survival rates, overall survival (OS), and progression-free survival (PFS). According to the inclusion and exclusion criteria, a total of 1294 patients with glioma were included in the final analysis of 31 articles, among which a 73.00% (95% CI, 68.00 ~ 79.00%, P < 0.01) rate of GTR in 27 groups included in 23 articles was reported for those receiving FGR. The OS was 17.78 months (95% CI, 8.89 ~ 26.67, P < 0.01) in 5 articles on PDT-treated patients with glioma, and the mean difference of OS was 6.18 (95% CI, 3.3 ~ 9.06, P < 0.01) between PDT treatment and conventional glioma surgery, showing a statistically significant difference (P < 0.01). The PFS was 10.82 months (95% CI, 7.04 ~ 14.61, P < 0.01) in 5 articles on PDT-treated patients with glioma. A 1-year survival rate of 59.00% (95% CI, 38.00 ~ 77.00%, P < 0.01) in 10 groups included in 8 articles and 2-year survival rate of 25.00% (95% CI, 15.00 ~ 36.00%, P < 0.01) in 7 groups included in 6 articles were reported for those with PDT. FGR and PDT are feasible for treatment of patients with glioma, because FGR can effectively increase the resection rate, at the same time, PDT can prolong the survival time. However, due to the limitation of small sample size in the existing studies, larger samples and randomized controlled clinical trials are needed to analyze the resection under FGR and efficacy of PDT in patients with glioma.

Correlation of immunohistochemical expression of HIF-1alpha and IDH1 with clinicopathological and therapeutic data of moroccan glioblastoma and survival analysis

INTRODUCTION

Glioblastomas are aggressive primary intracranial tumours of the central nervous system causing significant mortality and morbidity worldwide.

OBJECTIVE

This study aims to evaluate the prognostic value of tissue expression by immunostaining of hypoxia-inducible factor (HIF-1α), isocitrate dehydrogenase 1 (IDH1), and tumour protein p53 in glioblastoma in Moroccan patients. The association of HIF-1α, IDH1, and p53 expression with the clinicopathological data and overall patient survival (OS) was also evaluated.

MATERIALS AND METHODS

Confirmed glioblastomas were included in this study. Twenty-two tissue samples were obtained by neurosurgical intervention resulting from total resection, and subtotal resection or biopsy. Karnofsky index, histological type of tumour, and the status of IDH1, p53 protein, and HIF-1α expression by immunostaining were reported.

RESULTS

The majority of the patients were males (64%) with a sex ratio of 1.75. The average age was 54 ± 13. Median follow-up was 10.10 months and median overall survival was 10 months. The expression of HIF-1α was high in 10 samples (45%) and low in 12 (55%). There was a statistically significant difference in OS of 85% at 12 months for the subgroup of patients "HIF-1α negative IDH1 positive" p = 0.038, the unadjusted analysis showed that the group "HIF-1α positive, IDH1 positive" was a poor prognostic factor, the HR was 0.08 (95% CI: 0.009-0.756, p = 0.027).

CONCLUSION

Patients with negative HIF-1α expression and positive IDH1 expression have a better prognosis, suggesting that these two biomarkers may be useful in the search for new approaches for targeted therapy in glioblastoma.

Synthesis and Functionalisation of Superparamagnetic Nano-Rods towards the Treatment of Glioblastoma Brain Tumours

The complete removal of glioblastoma brain tumours is impossible to achieve by surgery alone due to the complex finger-like tentacle structure of the tumour cells and their migration away from the bulk of the tumour at the time of surgery; furthermore, despite aggressive chemotherapy and radiotherapy treatments following surgery, tumour cells continue to grow, leading to the death of patients within 15 months after diagnosis. The naturally occurring carnosine dipeptide has previously demonstrated activity against in vitro cultured glioblastoma cells; however, at natural physiological concentrations, its activity is too low to have a significant effect. Towards realising the full oncological potential of carnosine, the dipeptide was embedded within an externally triggered carrier, comprising a novel nano rod-shaped superparamagnetic iron oxide nanoparticle (ca. 86 × 19 × 11 nm) capped with a branched polyethyleneimine, which released the therapeutic agent in the presence of an external magnetic field. The new nano-carrier was characterized using electron microscopy, dynamic light scattering, elemental analysis, and magnetic resonance imaging techniques. In addition to cytotoxicity studies, the carnosine carrier’s effectiveness as a treatment for glioblastoma was screened in vitro using the U87 human glioblastoma astrocytoma cell line. The labile carnosine (100 mM) suppresses both the U87 cells’ proliferation and mobility over 48 h, resulting in significant reduction in migration and potential metastasis. Carnosine was found to be fully released from the carrier using only mild hyperthermia conditions (40 °C), facilitating an achievable clinical application of the slow, sustained-release treatment of glioblastoma brain tumours that demonstrates potential to inhibit post-surgery metastasis with the added benefit of non-invasive monitoring via MRI.

Key Points in Remote-Controlled Drug Delivery: From the Carrier Design to Clinical Trials

The increased research activity aiming at improved delivery of pharmaceutical molecules indicates the expansion of the field. An efficient therapeutic delivery approach is based on the optimal choice of drug-carrying vehicle, successful targeting, and payload release enabling the site-specific accumulation of the therapeutic molecules. However, designing the formulation endowed with the targeting properties in vitro does not guarantee its selective delivery in vivo. The various biological barriers that the carrier encounters upon intravascular administration should be adequately addressed in its overall design to reduce the off-target effects and unwanted toxicity in vivo and thereby enhance the therapeutic efficacy of the payload. Here, we discuss the main parameters of remote-controlled drug delivery systems: (i) key principles of the carrier selection; (ii) the most significant physiological barriers and limitations associated with the drug delivery; (iii) major concepts for its targeting and cargo release stimulation by external stimuli in vivo. The clinical translation for drug delivery systems is also described along with the main challenges, key parameters, and examples of successfully translated drug delivery platforms. The essential steps on the way from drug delivery system design to clinical trials are summarized, arranged, and discussed.

Neurocytological Advances in the Treatment of Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is an aggressive neoplasm of the brain that has commonly led to disappointing patient outcomes. Despite medical advancements and increasing research efforts, GBM studies reveal a stagnant survival rate at the global level with only sluggish improvement over time. Modern neuro-oncology research places a heavy emphasis on pharmacological therapies. Through a broad database search, we accumulated and synthesized the GBM-related neuroimmunocytological literature to create a comprehensive and contemporary review. Based on our findings, we discuss the recent neurocytological treatment strategies for GMB and the results of the studies. Regorafenib, paxalisib, and dianhydrogalactitol (VAL-083) are showing initial promise to decrease disease progression. VAL-083 is an alkylating agent that creates N7 methylation on DNA and has the ability to cross the blood-brain barrier (BBB). Selinexor, recombinant nonpathogenic polio-rhinovirus, and GBM-vaccine of autologous fibroblasts retrovirally transfected with TFG-IL4-Neo-TK vector have all also shown initial clinical benefit in terms of prolonging survival. Most trials observe modest improvement in outcomes with a positive safety profile. Nevertheless, the need for further studies is warranted, along with the trending of post-therapeutic biomarkers in order to better access future patient outcomes.

Effect of L- to D-Amino Acid Substitution on Stability and Activity of Antitumor Peptide RDP215 against Human Melanoma and Glioblastoma

The study investigates the antitumor effect of two cationic peptides, R-DIM-P-LF11-215 (RDP215) and the D-amino acid variant 9D-R-DIM-P-LF11-215 (9D-RDP215), targeting the negatively charged lipid phosphatidylserine (PS) exposed by cancer cells, such as of melanoma and glioblastoma. Model studies mimicking cancer and non-cancer membranes revealed the specificity for the cancer-mimic PS by both peptides with a slightly stronger impact by the D-peptide. Accordingly, membrane effects studied by DSC, leakage and quenching experiments were solely induced by the peptides when the cancer mimic PS was present. Circular dichroism revealed a sole increase in β-sheet conformation in the presence of the cancer mimic for both peptides; only 9D-RDP215 showed increased structure already in the buffer. Ex vitro stability studies by SDS-PAGE as well as in vitro with melanoma A375 revealed a stabilizing effect of D-amino acids in the presence of serum, which was also confirmed in 2D and 3D in vitro experiments on glioblastoma LN-229. 9D-RDP215 was additionally able to pass a BBB model, whereupon it induced significant levels of cell death in LN-229 spheroids. Summarized, the study encourages the introduction of D-amino acids in the design of antitumor peptides for the improvement of their stable antitumor activity.

A perspective on the radiopharmaceutical requirements for imaging and therapy of glioblastoma

Despite numerous clinical trials and pre-clinical developments, the treatment of glioblastoma (GB) remains a challenge. The current survival rate of GB averages one year, even with an optimal standard of care. However, the future promises efficient patient-tailored treatments, including targeted radionuclide therapy (TRT). Advances in radiopharmaceutical development have unlocked the possibility to assess disease at the molecular level allowing individual diagnosis. This leads to the possibility of choosing a tailored, targeted approach for therapeutic modalities. Therapeutic modalities based on radiopharmaceuticals are an exciting development with great potential to promote a personalised approach to medicine. However, an effective targeted radionuclide therapy (TRT) for the treatment of GB entails caveats and requisites. This review provides an overview of existing nuclear imaging and TRT strategies for GB. A critical discussion of the optimal characteristics for new GB targeting therapeutic radiopharmaceuticals and clinical indications are provided. Considerations for target selection are discussed, i.e. specific presence of the target, expression level and pharmacological access to the target, with particular attention to blood-brain barrier crossing. An overview of the most promising radionuclides is given along with a validation of the relevant radiopharmaceuticals and theranostic agents (based on small molecules, peptides and monoclonal antibodies). Moreover, toxicity issues and safety pharmacology aspects will be presented, both in general and for the brain in particular.

DDX60 Is Associated With Glioma Malignancy and Serves as a Potential Immunotherapy Biomarker

DDX60, an interferon (IFN)-inducible gene, plays a promotional role in many tumors. However, its function in glioma remains unknown. In this study, bioinformatic analysis (TCGA, CGGA, Rembrandt) illustrated the upregulation and prognostic value of DDX60 in gliomas. Immunohistochemical staining of clinical samples (n = 49) validated the DDX60 expression is higher in gliomas than in normal tissue (n = 20, P < 0.0001). It also could be included in nomogram as a parameter to predict the 3- and 5-year survival risk (C-index = 0.86). The biological process of DDX60 in glioma was mainly enriched in the inflammatory and immune response by GSEA and GO analysis. DDX60 expression had a positive association with most inflammatory-related functions, such as hematopoietic cell kinase (HCK) (R = 0.31), interferon (R = 0.72), STAT1 (R = 54), and a negative correlation with IgG (R = −0.24). Furthermore, DDX60 expression tends to be positively related to multiple infiltrating immune cells, while negatively related to CD56 dim nature killer cell in glioma. Some important immune checkpoints, like CTLA-4, PD-L1, EGF, CD96, and CD226, were all positively related with DDX60 (all Pearson correlation R > 0.26). The expression and correlation between DDX60, EGF, and PD-L1 were confirmed by western blot in clinical samples (n = 14, P < 0.0001) and GBM cells. These results indicated that DDX60 might have important clinical significance in glioma and could serve as a potential immune therapeutic target.

Highlights in targeted nanoparticles as a delivery strategy for glioma treatment

Glioma is the most common type of Central Nervous System (CNS) neoplasia and it arises from glial cells. As glial cells are formed by different types of cells, glioma can be classified according to the cells that originate it or the malignancy grade. Glioblastoma multiforme is the most common and aggressive glioma. The high lethality of this tumor is related to the difficulty in performing surgical removal, chemotherapy, and radiotherapy in the CNS. To improve glioma treatment, a wide range of chemotherapeutics have been encapsulated in nanosystems to increase their ability to overcome the blood-brain barrier (BBB) and specifically reach the tumoral cells, reducing side effects and improving drug concentration in the tumor microenvironment. Several studies have investigated nanosystems covered with targeting ligands (e.g., proteins, peptides, aptamers, folate, and glucose) to increase the ability of drugs to cross the BBB and enhance their specificity to glioma through specific recognition by receptors on BBB and glioma cells. This review addresses the main targeting ligands used in nanosystems to overcome the BBB and promote the active targeting of drugs for glioma. Furthermore, the advantages of using these molecules in glioma treatment are discussed.

NIR-II Absorbing Semiconducting Polymer-Triggered Gene-Directed Enzyme Prodrug Therapy for Cancer Treatment

Exploration of facile strategies for precise regulation of target gene expression remains highly challenging in the development of gene therapies. Especially, a stimuli-responsive nanocarrier integrated with ability of noninvasive remote control for treating wide types of cancers is rarely developed. Herein, a NIR-II absorbing semiconducting polymer (PBDTQ) is employed to remotely activate the heat-inducible heat-shock protein 70 (HSP70) promoter under laser irradiation, further realizing regulation of gene-directed enzyme prodrug therapy (GDEPT) for cancer treatment in mild hyperthermia. In this multifunctional nanocomposite, the PBDTQ and double suicide gene plasmid (pSG) based on HSP70 promoter are incorporated into a lipid complex. Upon NIR-II laser excitation, the mild photothermal effect (≈43 °C) generated from PBDTQ can cause the release of pSG and activation of HSP70 promoter, and then upregulate suicide gene expression triggered by the HSP70 promoter which can further convert the nontoxic prodrug into its cytotoxic metabolites. Therefore, this work demonstrates a universal NIR-II laser-triggered GDEPT using semiconducting polymers as the photothermal generator for cancer treatment with minimized collateral damage and nontargeted side effects.

Diffusion weighted imaging in high-grade gliomas: A histogram-based analysis of apparent diffusion coefficient profile

Purpose

Glioblastoma and anaplastic astrocytoma represent the most commonly encountered high-grade-glioma (HGG) in adults. Although both neoplasms are very distinct entities in context of epidemiology, clinical course and prognosis, their appearance in conventional magnetic resonance imaging (MRI) is very similar. In search for additional information aiding the distinction of potentially confusable neoplasms, histogram analysis of apparent diffusion coefficient (ADC) maps recently proved to be auxiliary in a number of entities. Therefore, our present exploratory retrospective study investigated whether ADC histogram profile parameters differ significantly between anaplastic astrocytoma and glioblastoma, reflect the proliferation index Ki-67, or are associated with the prognostic relevant MGMT (methylguanine-DNA methyl-transferase) promotor methylation status.

Methods

Pre-surgical ADC volumes of 56 HGG patients were analyzed by histogram-profiling. Association between extracted histogram parameters and neuropathology including WHO-grade, Ki-67 expression and MGMT promotor methylation status was investigated due to comparative and correlative statistics.

Results

Grade IV gliomas were more heterogeneous than grade III tumors. More specifically, ADCmin and the lowest percentile ADCp10 were significantly lower, whereas ADCmax, ADC standard deviation and Skewness were significantly higher in the glioblastoma group. ADCmin, ADCmax, ADC standard deviation, Kurtosis and Entropy of ADC histogram were significantly correlated with Ki-67 expression. No significant difference could be revealed by comparison of ADC histogram parameters between MGMT promotor methylated and unmethylated HGG.

Conclusions

ADC histogram parameters differ significantly between glioblastoma and anaplastic astrocytoma and show distinct associations with the proliferative activity in both HGG. Our results suggest ADC histogram profiling as promising biomarker for differentiation of both, however, further studies with prospective multicenter design are wanted to confirm and further elaborate this hypothesis.

A Systematic Review of Glioblastoma-Targeted Therapies in Phases II, III, IV Clinical Trials

Glioblastoma (GBM), the most frequent and aggressive glial tumor, is currently treated as first line by the Stupp protocol, which combines, after surgery, radiotherapy and chemotherapy. For recurrent GBM, in absence of standard treatment or available clinical trials, various protocols including cytotoxic drugs and/or bevacizumab are currently applied. Despite these heavy treatments, the mean overall survival of patients is under 18 months. Many clinical studies are underway. Based on clinicaltrials.org and conducted up to 1 April 2020, this review lists, not only main, but all targeted therapies in phases II-IV of 257 clinical trials on adults with newly diagnosed or recurrent GBMs for the last twenty years. It does not involve targeted immunotherapies and therapies targeting tumor cell metabolism, that are well documented in other reviews. Without surprise, the most frequently reported drugs are those targeting (i) EGFR (40 clinical trials), and more generally tyrosine kinase receptors (85 clinical trials) and (ii) VEGF/VEGFR (75 clinical trials of which 53 involving bevacizumab). But many other targets and drugs are of interest. They are all listed and thoroughly described, on an one-on-one basis, in four sections related to targeting (i) GBM stem cells and stem cell pathways, (ii) the growth autonomy and migration, (iii) the cell cycle and the escape to cell death, (iv) and angiogenesis.

Machine Learning for the Prediction of Molecular Markers in Glioma on Magnetic Resonance Imaging: A Systematic Review and Meta-Analysis

BACKGROUND

Molecular characterization of glioma has implications for prognosis, treatment planning, and prediction of treatment response. Current histopathology is limited by intratumoral heterogeneity and variability in detection methods. Advances in computational techniques have led to interest in mining quantitative imaging features to noninvasively detect genetic mutations.

OBJECTIVE

To evaluate the diagnostic accuracy of machine learning (ML) models in molecular subtyping gliomas on preoperative magnetic resonance imaging (MRI).

METHODS

A systematic search was performed following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines to identify studies up to April 1, 2020. Methodological quality of studies was assessed using the Quality Assessment for Diagnostic Accuracy Studies (QUADAS)-2. Diagnostic performance estimates were obtained using a bivariate model and heterogeneity was explored using metaregression.

RESULTS

Forty-four original articles were included. The pooled sensitivity and specificity for predicting isocitrate dehydrogenase (IDH) mutation in training datasets were 0.88 (95% CI 0.83-0.91) and 0.86 (95% CI 0.79-0.91), respectively, and 0.83 to 0.85 in validation sets. Use of data augmentation and MRI sequence type were weakly associated with heterogeneity. Both O6-methylguanine-DNA methyltransferase (MGMT) gene promoter methylation and 1p/19q codeletion could be predicted with a pooled sensitivity and specificity between 0.76 and 0.83 in training datasets.

CONCLUSION

ML application to preoperative MRI demonstrated promising results for predicting IDH mutation, MGMT methylation, and 1p/19q codeletion in glioma. Optimized ML models could lead to a noninvasive, objective tool that captures molecular information important for clinical decision making. Future studies should use multicenter data, external validation and investigate clinical feasibility of ML models.

Diagnosis and Management of Glioblastoma: A Comprehensive Perspective

Glioblastoma is the most common malignant brain tumor in adults. The current management relies on surgical resection and adjuvant radiotherapy and chemotherapy. Despite advances in our understanding of glioblastoma onset, we are still faced with an increased incidence, an altered quality of life and a poor prognosis, its relapse and a median overall survival of 15 months. For the past few years, the understanding of glioblastoma physiopathology has experienced an exponential acceleration and yielded significant insights and new treatments perspectives. In this review, through an original R-based literature analysis, we summarize the clinical presentation, current standards of care and outcomes in patients diagnosed with glioblastoma. We also present the recent advances and perspectives regarding pathophysiological bases as well as new therapeutic approaches such as cancer vaccination and personalized treatments.

Perspective of mesenchymal transformation in glioblastoma

Despite aggressive multimodal treatment, glioblastoma (GBM), a grade IV primary brain tumor, still portends a poor prognosis with a median overall survival of 12–16 months. The complexity of GBM treatment mainly lies in the inter- and intra-tumoral heterogeneity, which largely contributes to the treatment-refractory and recurrent nature of GBM. By paving the road towards the development of personalized medicine for GBM patients, the cancer genome atlas classification scheme of GBM into distinct transcriptional subtypes has been considered an invaluable approach to overcoming this heterogeneity. Among the identified transcriptional subtypes, the mesenchymal subtype has been found associated with more aggressive, invasive, angiogenic, hypoxic, necrotic, inflammatory, and multitherapy-resistant features than other transcriptional subtypes. Accordingly, mesenchymal GBM patients were found to exhibit worse prognosis than other subtypes when patients with high transcriptional heterogeneity were excluded. Furthermore, identification of the master mesenchymal regulators and their downstream signaling pathways has not only increased our understanding of the complex regulatory transcriptional networks of mesenchymal GBM, but also has generated a list of potent inhibitors for clinical trials. Importantly, the mesenchymal transition of GBM has been found to be tightly associated with treatment-induced phenotypic changes in recurrence. Together, these findings indicate that elucidating the governing and plastic transcriptomic natures of mesenchymal GBM is critical in order to develop novel and selective therapeutic strategies that can improve both patient care and clinical outcomes. Thus, the focus of our review will be on the recent advances in the understanding of the transcriptome of mesenchymal GBM and discuss microenvironmental, metabolic, and treatment-related factors as critical components through which the mesenchymal signature may be acquired. We also take into consideration the transcriptomic plasticity of GBM to discuss the future perspectives in employing selective therapeutic strategies against mesenchymal GBM.

Mutation-based clustering and classification analysis reveals distinctive age groups and age-related biomarkers for glioma

BACKGROUND

Malignant brain tumor diseases exhibit differences within molecular features depending on the patient's age.

METHODS

In this work, we use gene mutation data from public resources to explore age specifics about glioma. We use both an explainable clustering as well as classification approach to find and interpret age-based differences in brain tumor diseases. We estimate age clusters and correlate age specific biomarkers.

RESULTS

Age group classification shows known age specifics but also points out several genes which, so far, have not been associated with glioma classification.

CONCLUSIONS

We highlight mutated genes to be characteristic for certain age groups and suggest novel age-based biomarkers and targets.

Challenges and Perspectives of Standard Therapy and Drug Development in High-Grade Gliomas

Despite their low incidence rate globally, high-grade gliomas (HGG) remain a fatal primary brain tumor. The recommended therapy often is incapable of resecting the tumor entirely and exclusively targeting the tumor leads to tumor recurrence and dismal prognosis. Additionally, many HGG patients are not well suited for standard therapy and instead, subjected to a palliative approach. HGG tumors are highly infiltrative and the complex tumor microenvironment as well as high tumor heterogeneity often poses the main challenges towards the standard treatment. Therefore, a one-fit-approach may not be suitable for HGG management. Thus, a multimodal approach of standard therapy with immunotherapy, nanomedicine, repurposing of older drugs, use of phytochemicals, and precision medicine may be more advantageous than a single treatment model. This multimodal approach considers the environmental and genetic factors which could affect the patient's response to therapy, thus improving their outcome. This review discusses the current views and advances in potential HGG therapeutic approaches and, aims to bridge the existing knowledge gap that will assist in overcoming challenges in HGG.

Pathogenetic Features and Current Management of Glioblastoma

Glioblastoma (GBM) is the most common form of primary malignant brain tumor with a devastatingly poor prognosis. The disease does not discriminate, affecting adults and children of both sexes, and has an average overall survival of 12-15 months, despite advances in diagnosis and rigorous treatment with chemotherapy, radiation therapy, and surgical resection. In addition, most survivors will eventually experience tumor recurrence that only imparts survival of a few months. GBM is highly heterogenous, invasive, vascularized, and almost always inaccessible for treatment. Based on all these outstanding obstacles, there have been tremendous efforts to develop alternative treatment options that allow for more efficient targeting of the tumor including small molecule drugs and immunotherapies. A number of other strategies in development include therapies based on nanoparticles, light, extracellular vesicles, and micro-RNA, and vessel co-option. Advances in these potential approaches shed a promising outlook on the future of GBM treatment. In this review, we briefly discuss the current understanding of adult GBM's pathogenetic features that promote treatment resistance. We also outline novel and promising targeted agents currently under development for GBM patients during the last few years with their current clinical status.

The Paired Siglecs in Brain Tumours Therapy: The Immunomodulatory Effect of Dexamethasone and Temozolomide in Human Glioma In Vitro Model

The paired sialic acid-binding immunoglobulin like lectins (Siglecs) are characterized by similar cellular distribution and ligand recognition but opposing signalling functions attributed to different intracellular sequences. Since sialic acid—Siglec axis are known to control immune homeostasis, the imbalance between activatory and inhibitory mechanisms of glycan-dependent immune control is considered to promote pathology. The role of sialylation in cancer is described, however, its importance in immune regulation in gliomas is not fully understood. The experimental and clinical observation suggest that dexamethasone (Dex) and temozolomide (TMZ), used in the glioma management, alter the immunity within the tumour microenvironment. Using glioma-microglia/monocytes transwell co-cultures, we investigated modulatory action of Dex/TMZ on paired Siglecs. Based on real-time PCR and flow cytometry, we found changes in SIGLEC genes and their products. These effects were accompanied by altered cytokine profile and immune cells phenotype switching measured by arginases expression. Additionally, the exposure to Dex or TMZ increased the binding of inhibitory Siglec-5 and Siglec-11 fusion proteins to glioma cells. Our study suggests that the therapy-induced modulation of the interplay between sialoglycans and paired Siglecs, dependently on patient’s phenotype, is of particular signification in the immune surveillance in the glioma management and may be useful in glioma patient’s therapy plan verification.

The Survival Benefit of Postoperative Bacterial Infections in Patients With Glioblastoma Multiforme: Myth or Reality?

Glioblastoma multiforme (GBM), the most common malignant brain tumor, universally carries a poor prognosis. Despite aggressive multimodality treatment, the median survival is ~18-20 months, depending on molecular subgroups. A long history of observations suggests antitumor effects of bacterial infections against malignant tumors. The present review summarizes and critically analyzes the clinical data providing evidence for or against the survival benefit of post-operative bacterial infections in GBM patients. Furthermore, we explore the probable underlying mechanism(s) from basic science studies on the topic. There are plausible explanations from immunobiology for the mechanism of the "favorable effect" of bacterial infections in GBM patients. However, available clinical literature does not provide a definitive association between postoperative bacterial infection and prolonged survival in GBM patients. The presently available, single-/multi-center and national database retrospective case-control studies on the topic provide conflicting results. A prospective randomized study on the subject is clearly not possible. Immunobiology literature supports development of genetically modified bacteria as part of multimodal regimen against GBM.

Design, Synthesis and Biological Evaluation of New Pyrimidine Derivatives as Anticancer Agents

Background: Anticancer drug resistance is a challenging phenomenon of growing concern which arises from alteration in drug targets. Despite the fast speed of new chemotherapeutic agent design, the increasing prevalence of this phenomenon requires further research and treatment development. Recently, we reported a new aminopyrimidine compound—namely RDS 344—as a potential innovative anticancer agent. Methods: Herein, we report the design, synthesis, and anti-proliferative activity of new aminopyrimidine derivatives structurally related to RDS 3442 obtained by carrying out substitutions at position 6 of the pyrimidine core and/or on the 2-aniline ring of our hit. The ability to inhibit cell proliferation was evaluated on different types of tumors, glioblastoma, triple-negative breast cancer, oral squamous cell carcinomas and colon cancer plus on human dermal fibroblasts chosen as control of normal cells. Results: The most interesting compound was the N-benzyl counterpart of RDS 3442, namely 2a, that induced a significant decrease in cell viability in all the tested tumor cell lines, with EC₅₀s ranging from 4 and 8 μM, 4–13 times more active of hit. Conclusions: These data suggest a potential role for this class of molecules as promising tool for new approaches in treating cancers of different histotype.

Safety and interim survival data after intracranial administration of M032, a genetically engineered oncolytic HSV-1 expressing IL-12, in pet dogs with sporadic gliomas

OBJECTIVE

The diagnosis of glioma remains disheartening in the clinical realm. While a multitude of studies and trials have shown promise, improvements in overall survival have been disappointing. Modeling these tumors in the laboratory setting has become increasingly challenging, given their complex in situ behavior and interactions for therapeutic evasion. Dogs, particularly brachycephalic breeds, are known to spontaneously develop gliomas that resemble human gliomas both clinically and pathophysiologically, making canines with sporadic tumors promising candidates for study. Typically, survival among these dogs is approximately 2 months with palliation alone.

METHODS

The authors have completed the first stage of a unique phase I dose-escalating canine clinical trial in which the safety and tolerability of M032, a nonneurovirulent oncolytic herpes simplex virus-1 vector genetically engineered to express interleukin-12, are being studied in pet dogs with gliomas undergoing maximum safe tumor resection and inoculation of the cavity with the viral infusate.

RESULTS

Twenty-five canine patients were enrolled between January 2018 and August 2020. One patient was electively withdrawn from the trial by its owner, and 3 did not receive the virus. For the 21 dogs that remained, 13 had high-grade gliomas, 5 had low-grade gliomas, and 3 were undetermined. According to histopathological analysis, 62% of the tumors were oligodendrogliomas. At the time of this report, the median overall survival from the date of treatment was 151 days (± 78 days). No significant adverse events attributable to M032 or dose-limiting toxicities have been observed to date.

CONCLUSIONS

In this largest study of oncolytic viral therapy for canine brain tumors to date, treatment with M032 did not cause harm and the combination of surgery and oncolytic viral therapy may have contributed to prolonged survival in pet dogs with spontaneous gliomas. Forthcoming in-depth radiographic, immunohistochemical, and genetic analyses will afford a more advanced understanding of how this treatment impacts these tumors and the immune system. Our goal is to utilize these findings bitranslationally to inform human studies and refine therapies that will improve outcomes in both humans and pet dogs with gliomas.

Glioblastoma Break-in; Try Something New

Context: Glioblastoma is the most invasive brain tumor with a poor prognosis and rapid progression. The standard therapy (surgical resection, adjuvant chemotherapy, and radiotherapy) ensures survival only up to 18 months. In this article, we focus on innovative types of radiotherapy, various combinations of temozolomide with novel substances, and methods of their administration and vector delivery to tumor cells. Evidence Acquisition: For a detailed study of the various options for chemotherapy and radiotherapy, Elsevier, NCBI MedLine, Scopus, Google Scholar, Embase, Web of Science, The Cochrane Library, EMBASE, Global Health, CyberLeninka, and RSCI databases were analyzed. Results: The most available method is oral or intravenous administration of temozolomide. More efficient is the combined chemotherapy of temozolomide with innovative drugs and substances such as lomustine, histone deacetylase inhibitors, and chloroquine, as well as olaparib. These combinations improve patient survival and are effective in the treatment of resistant tumors. Compared to standard fractionated radiotherapy (60 Gy, 30 fractions, 6 weeks), hypofractionated is more effective for elderly patients due to lack of toxicity; brachytherapy reduces the risk of glioblastoma recurrence, while radiosurgery with bevacizumab is more effective against recurrent or inoperable tumors. Currently, the most effective treatment is considered to be the intranasal administration of anti-Ephrin A3 (anti-EPHA3)-modified containing temozolomide butyl ester-loaded (TBE-loaded) poly lactide-co-glycolide nanoparticles (P-NPs) coated with N-trimethylated chitosan (TMC) to overcome nasociliary clearance. Conclusions: New radiotherapeutic methods significantly increase the survival rates of glioblastoma patients. With some improvement, it may lead to the elimination of all tumor cells leaving the healthy alive. New chemotherapeutic drugs show impressive results with adjuvant temozolomide. Anti-EPHA3-modified TBE-loaded P-NPs coated with TMC have high absorption specificity and kill glioblastoma cells effectively. A new “step forward” may become a medicine of the future, which reduces the specific accumulation of nanoparticles in the lungs, but simultaneously does not affect specific absorption by tumor cells.

Multi-institutional noninvasive in vivo characterization of IDH, 1p/19q, and EGFRvIII in glioma using neuro-Cancer Imaging Phenomics Toolkit (neuro-CaPTk)

Background

Gliomas represent a biologically heterogeneous group of primary brain tumors with uncontrolled cellular proliferation and diffuse infiltration that renders them almost incurable, thereby leading to a grim prognosis. Recent comprehensive genomic profiling has greatly elucidated the molecular hallmarks of gliomas, including the mutations in isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2), loss of chromosomes 1p and 19q (1p/19q), and epidermal growth factor receptor variant III (EGFRvIII). Detection of these molecular alterations is based on ex vivo analysis of surgically resected tissue specimen that sometimes is not adequate for testing and/or does not capture the spatial tumor heterogeneity of the neoplasm.

Methods

We developed a method for noninvasive detection of radiogenomic markers of IDH both in lower-grade gliomas (WHO grade II and III tumors) and glioblastoma (WHO grade IV), 1p/19q in IDH-mutant lower-grade gliomas, and EGFRvIII in glioblastoma. Preoperative MRIs of 473 glioma patients from 3 of the studies participating in the ReSPOND consortium (collection I: Hospital of the University of Pennsylvania [HUP: n = 248], collection II: The Cancer Imaging Archive [TCIA; n = 192], and collection III: Ohio Brain Tumor Study [OBTS, n = 33]) were collected. Neuro-Cancer Imaging Phenomics Toolkit (neuro-CaPTk), a modular platform available for cancer imaging analytics and machine learning, was leveraged to extract histogram, shape, anatomical, and texture features from delineated tumor subregions and to integrate these features using support vector machine to generate models predictive of IDH, 1p/19q, and EGFRvIII. The models were validated using 3 configurations: (1) 70-30% training-testing splits or 10-fold cross-validation within individual collections, (2) 70-30% training-testing splits within merged collections, and (3) training on one collection and testing on another.

Results

These models achieved a classification accuracy of 86.74% (HUP), 85.45% (TCIA), and 75.15% (TCIA) in identifying EGFRvIII, IDH, and 1p/19q, respectively, in configuration I. The model, when applied on combined data in configuration II, yielded a classification success rate of 82.50% in predicting IDH mutation (HUP + TCIA + OBTS). The model when trained on TCIA dataset yielded classification accuracy of 84.88% in predicting IDH in HUP dataset.

Conclusions

Using machine learning algorithms, high accuracy was achieved in the prediction of IDH, 1p/19q, and EGFRvIII mutation. Neuro-CaPTk encompasses all the pipelines required to replicate these analyses in multi-institutional settings and could also be used for other radio(geno)mic analyses.

A contemporary update on glioblastoma: molecular biology, current management, and a vision towards bio-adaptable personalized care

INTRODUCTION

Glioblastoma (GBM) is the most fatal brain tumor in adults. Current survival rates of GBM remain below 2 years due to GBM's aggressive cellular migration and genetically driven treatment escape pathways. Despite our rapidly increasing understanding of GBM biology, earlier diagnoses, and refined surgical techniques, only moderate survival benefits have been achieved. Nonetheless, the pressing need for better survival rates has brought forward a multitude of newer therapeutic approaches and opened the door for potential personalization of these modalities in the near future.

METHODS

We reviewed the published literature discussing the current state of knowledge regarding GBM biology and therapy and summarized the information that may point toward future personalized therapeutic strategies.

RESULTS

Several novel modalities such as oncolytic viruses, targeted immune, and molecular therapies, and tumor treating fields have been introduced. To date, there is no single treatment modality for GBM, but rather a wide spectrum of combined modalities that address intratumoral cellular and genetic variabilities. While the current state of GBM research and clinical trial landscape may hold promise, current literature lacks any fruitful progress towards personalized GBM therapy.

CONCLUSION

In this review, we are discussing our recent knowledge of the GBM genetic biologic landscape and the current advances in therapy, as well as providing a blueprint for an envisioned GBM management paradigm that should be personalized and adaptable to accommodate each patient's diverse genetic variations and therapy response/escape patterns.

Immunologic aspects of viral therapy for glioblastoma and implications for interactions with immunotherapies

INTRODUCTION

The treatment for glioblastoma (GBM) has remained unchanged for the past decade, with only minimal improvements in patient survival. As a result, novel treatments are needed to combat this devastating disease. Immunotherapies are treatments that stimulate the immune system to attack tumor cells and can be either local or systemically delivered. Viral treatments can lead to direct tumor cell death through their natural lifecycle or through the delivery of a suicide gene, with the potential to generate an anti-tumor immune response, making them interesting candidates for combinatorial treatment with immunotherapy.

METHODS

We review the current literature surrounding the interactions between oncolytic viruses and the immune system as well as the use of oncolytic viruses combined with immunotherapies for the treatment of GBM.

RESULTS

Viral therapies have exhibited preclinical efficacy as single-agents and are being investigated in that manner in clinical trials. Oncolytic viruses have significant interactions with the immune system, although this can also vary depending on the strain of virus. Combinatorial treatments using both oncolytic viruses and immunotherapies have demonstrated promising preclinical findings.

CONCLUSIONS

Studies combining viral and immunotherapeutic treatment modalities have provided exciting results thus far and hold great promise for patients with GBM. Additional studies assessing the clinical efficacy of these treatments as well as improved preclinical modeling systems, safety mechanisms, and the balance between treatment efficacy and immune-mediated viral clearance should be considered.

Randomized Controlled Immunotherapy Clinical Trials for GBM Challenged

Simple Summary

Although multiple meta-analyses on active specific immunotherapy treatment for glioblastoma multiforme (GBM) have demonstrated a significant prolongation of overall survival, no single research group has succeeded in demonstrating the efficacy of this type of treatment in a prospective, double-blind, placebo-controlled, randomized clinical trial. In this paper, we explain how the complexity of the tumor biology and tumor–host interactions make proper stratification of a control group impossible. The individualized characteristics of advanced therapy medicinal products for immunotherapy contribute to heterogeneity within an experimental group. The dynamics of each tumor and in each patient aggravate comparative stable patient groups. Finally, combinations of immunotherapy strategies should be integrated with first-line treatment. We illustrate the complexity of a combined first-line treatment with individualized multimodal immunotherapy in a group of 70 adults with GBM and demonstrate that the integration of immunogenic cell death treatment within maintenance chemotherapy followed by dendritic cell vaccines and maintenance immunotherapy might provide a step towards improving the overall survival rate of GBM patients.

Abstract

Immunotherapies represent a promising strategy for glioblastoma multiforme (GBM) treatment. Different immunotherapies include the use of checkpoint inhibitors, adoptive cell therapies such as chimeric antigen receptor (CAR) T cells, and vaccines such as dendritic cell vaccines. Antibodies have also been used as toxin or radioactive particle delivery vehicles to eliminate target cells in the treatment of GBM. Oncolytic viral therapy and other immunogenic cell death-inducing treatments bridge the antitumor strategy with immunization and installation of immune control over the disease. These strategies should be included in the standard treatment protocol for GBM. Some immunotherapies are individualized in terms of the medicinal product, the immune target, and the immune tumor–host contact. Current individualized immunotherapy strategies focus on combinations of approaches. Standardization appears to be impossible in the face of complex controlled trial designs. To define appropriate control groups, stratification according to the Recursive Partitioning Analysis classification, MGMT promotor methylation, epigenetic GBM sub-typing, tumor microenvironment, systemic immune functioning before and after radiochemotherapy, and the need for/type of symptom-relieving drugs is required. Moreover, maintenance of a fixed treatment protocol for a dynamic, deadly cancer disease in a permanently changing tumor–host immune context might be inappropriate. This complexity is illustrated using our own data on individualized multimodal immunotherapies for GBM. Individualized medicines, including multimodal immunotherapies, are a rational and optimal yet also flexible approach to induce long-term tumor control. However, innovative methods are needed to assess the efficacy of complex individualized treatments and implement them more quickly into the general health system.