Unveiling the Dynamics behind Glioblastoma Multiforme Single-Cell Data Heterogeneity

Glioblastoma Multiforme is a brain tumor distinguished by its aggressiveness. We suggested that this aggressiveness leads single-cell RNA-sequence data (scRNA-seq) to span a representative portion of the cancer attractors domain. This conjecture allowed us to interpret the scRNA-seq heterogeneity as reflecting a representative trajectory within the attractor's domain. We considered factors such as genomic instability to characterize the cancer dynamics through stochastic fixed points. The fixed points were derived from centroids obtained through various clustering methods to verify our method sensitivity. This methodological foundation is based upon sample and time average equivalence, assigning an interpretative value to the data cluster centroids and supporting parameters estimation. We used stochastic simulations to reproduce the dynamics, and our results showed an alignment between experimental and simulated dataset centroids. We also computed the Waddington landscape, which provided a visual framework for validating the centroids and standard deviations as characterizations of cancer attractors. Additionally, we examined the stability and transitions between attractors and revealed a potential interplay between subtypes. These transitions might be related to cancer recurrence and progression, connecting the molecular mechanisms of cancer heterogeneity with statistical properties of gene expression dynamics. Our work advances the modeling of gene expression dynamics and paves the way for personalized therapeutic interventions.

An MRI Radiomics Approach to Predict the Hypercoagulable Status of Gliomas

Venous thromboembolic events are frequent complications of Glioblastoma Multiforme (GBM) and low-grade gliomas (LGGs). The overexpression of tissue factor (TF) plays an essential role in the local hypercoagulable phenotype that underlies these complications. Our aim was to build an MRI radiomics model for the non-invasive exploration of the hypercoagulable status of LGG/GBM. Radiogenomics data from The Cancer Genome Atlas (TCGA) and REMBRANDT (Repository for molecular BRAin Neoplasia DaTa) cohorts were used. A logistic regression model (Radscore) was built in order to identify the top 20% TF-expressing tumors, considered to be at high thromboembolic risk. The most contributive MRI radiomics features from LGG/GBM linked to high TF were identified in TCGA using Least Absolute Shrinkage and Selection Operator (LASSO) regression. A logistic regression model was built, whose performance was analyzed with ROC in the TCGA/training and REMBRANDT/validation cohorts: AUC = 0.87 [CI95: 0.81-0.94, p < 0.0001] and AUC = 0.78 [CI95: 0.56-1.00, p = 0.02], respectively. In agreement with the key role of the coagulation cascade in gliomas, LGG patients with a high Radscore had lower overall and disease-free survival. The Radscore was linked to the presence of specific genomic alterations, the composition of the tumor coagulome and the tumor immune infiltrate. Our findings suggest that a non-invasive assessment of the hypercoagulable status of LGG/GBM is possible with MRI radiomics.

Genetic Variants Impacting Angiogenesis Signaling Pathways in Glioblastoma Multiforme: A Systematic Review of Mutations and Polymorphisms

BACKGROUND

Several signaling pathways are involved in the process of angiogenesis, which is one of the most important hallmarks of glioblastoma multiforme (GBM). Identifying related gene variants can help researchers work out what causes anti-angiogenesis drug resistance.

OBJECTIVE

The goal of this systematic analysis was to identify all mutations and polymorphisms involved in angiogenesis pathways in GBM and their impact on clinical outcomes.

METHODS

The keywords include glioblastoma, angiogenesis, signaling pathway, mutation, polymorphism, and related terms used to search ISI, PubMed, and Scopus for relevant articles published up to January 2022. The PRISMA protocol was used to conduct our systematic review. The related articles were taken into consideration. The risk of bias in the associated articles was surveyed, as well as the article scoring. Two authors collaborated on data extraction.

RESULTS

The inclusion criteria were included in 32 articles out of a total of 787 articles. VEGF, HIF1a, EGFR, PI3K, and MAPK are the pathways that have been studied the most. IDH1, VEGF, VEGFR, EGFR, and HIF1a are the genes with the highest frequency of mutations or polymorphisms.

CONCLUSION

In conclusion, this study found that angiogenesis in primary or recurrent GBM is linked to gene changes in eleven signaling pathways. However, some of these gene mutations have been researched numerous times in relation to angiogenesis, while others have only been studied once. Understanding these changes will help us employ combination therapies more effectively for GBM patients' survival and personal medicine.

Study on the activation of cell death mechanisms: in search of new therapeutic targets in glioblastoma multiforme

Malignant primary brain tumors remain among the most difficult cancers to treat, in particular, Glioblastoma Multiforme (GBM) is the deadliest brain tumor. The standard therapies currently used are not efficient enough in improving patients' survival and quality of life. Cisplatin (CDDP), a platinum-based drug, has shown efficacy against different solid neoplasms, but it is also associated to different forms of off-target toxicity. To overcome the limitation in the use of CDDP in the treatment of GBM patients, fourth generation platinum compounds are been synthesized, one of them is the Pt(IV)Ac-POA, a prodrug with a medium-chain fatty acid as axial ligand, which acts as a histone 3 deacetylase inhibitor. Moreover, recently, the antioxidant effects of medicinal mushrooms have been shown to induce a lowering of the toxicity of chemotherapy drugs, inducing greater therapeutic efficiency, thus the combined therapy of chemotherapy and micotherapy could be helpful in the treatment of GBM reducing the adverse effects of the former thanks to phytotherapy's antioxidant, anti-inflammatory, immunomodulatory and antitumoral activities. Here, through immunoblotting, ultrastructural and immunofluorescence analysis, we evaluated the contribution in the activation of different cell death pathway of Micotherapy U-Care, a medicinal blend supplement, used together with platinum-based compounds on human glioblastoma U251 cells.

Biomarkers of Tumor Heterogeneity in Glioblastoma Multiforme Cohort of TCGA

Tumor Whole Slide Images (WSI) are often heterogeneous, which hinders the discovery of biomarkers in the presence of confounding clinical factors. In this study, we present a pipeline for identifying biomarkers from the Glioblastoma Multiforme (GBM) cohort of WSIs from TCGA archive. The GBM cohort endures many technical artifacts while the discovery of GBM biomarkers is challenged because "age" is the single most confounding factor for predicting outcomes. The proposed approach relies on interpretable features (e.g., nuclear morphometric indices), effective similarity metrics for heterogeneity analysis, and robust statistics for identifying biomarkers. The pipeline first removes artifacts (e.g., pen marks) and partitions each WSI into patches for nuclear segmentation via an extended U-Net for subsequent quantitative representation. Given the variations in fixation and staining that can artificially modulate hematoxylin optical density (HOD), we extended Navab's Lab method to normalize images and reduce the impact of batch effects. The heterogeneity of each WSI is then represented either as probability density functions (PDF) per patient or as the composition of a dictionary predicted from the entire cohort of WSIs. For PDF- or dictionary-based methods, morphometric subtypes are constructed based on distances computed from optimal transport and linkage analysis or consensus clustering with Euclidean distances, respectively. For each inferred subtype, Kaplan-Meier and/or the Cox regression model are used to regress the survival time. Since age is the single most important confounder for predicting survival in GBM and there is an observed violation of the proportionality assumption in the Cox model, we use both age and age-squared coupled with the Likelihood ratio test and forest plots for evaluating competing statistics. Next, the PDF- and dictionary-based methods are combined to identify biomarkers that are predictive of survival. The combined model has the advantage of integrating global (e.g., cohort scale) and local (e.g., patient scale) attributes of morphometric heterogeneity, coupled with robust statistics, to reveal stable biomarkers. The results indicate that, after normalization of the GBM cohort, mean HOD, eccentricity, and cellularity are predictive of survival. Finally, we also stratified the GBM cohort as a function of EGFR expression and published genomic subtypes to reveal genomic-dependent morphometric biomarkers.

Novel Derivatives of Tetrahydrobenzo (g) Imidazo[α-1,2] Quinoline Induce Apoptosis Via ROS Production in the Glioblastoma Multiforme Cells, U-87MG

BACKGROUND

Despite newer therapeutic approaches against glioblastoma multiforme (GBM), the severely poor prognosis and treatment resistance are still disadvantages that slow down the patient's recovery process. Consistent with the need to develop more effective and optimized therapies to control GBM cell growth, the effects of a new series of tetrahydrobenzo(g)imidazo[α-1,2]quinolone derivatives on GBM cell growth and the underlying mechanism is investigated in the current study.

METHODS

U-87MG cell line, glioblastoma multiforme and normal skin fibroblast cell line, AGO1522 were used to study the anticancer effects of 5 derivatives of tetrahydrobenzo(g)imidazo[α-1,2]quinolone and paclitaxel as a standard drug. The cytotoxic effect on cell growth was assessed using the MTT assay. Annexin V FITC staining and PI staining were applied to detect apoptosis and cell cycle distribution using flow cytometry. The extent of reactive oxygen species (ROS) formation was assessed using the fluorescent probe 7-dichlorofluorescin diacetate and caspase-3 activity using the colorimetric assay kit.

RESULTS

Among the 5 derivatives of tetrahydrobenzo(g)imidazo[α-1,2]quinolone, the 5c derivative (5-(6-bromo-2-chloroquinolin-3-yl)-9a-hydroxy-8,8-dimethyl-4-Nitro-2,3,5,5a,7,8,9,9a-octahydroimidazo[α-1,2]quinoline-6(1H)) showed the strongest cytotoxic effect on U-87MG cells in a time and Dose-dependent manner compared to the other derivatives and paclitaxel. The IC50 (11.91 M) of the 5c derivative induced apoptosis accompanied by a significant increase in sub-G1 and super-G2 phases of U-87MG cells. The increased level of cellular ROS and caspase 3 activity after treatment of U-87MG cells with 5c derivative was significant compared to untreated cells.

CONCLUSION

Our data provide insights into the potent anticancer effects of the 5c-derivative of tetrahydrobenzo(g)imidazo[α-1,2]quinolone on GBM cells via the caspase-dependent apoptotic pathway, which may merit further attention.

The power of a novel combined anticancer therapy: challenge and opportunity of micotherapy in the treatment of Glioblastoma Multiforme

Glioblastoma (GBM) is the most common and mortal primary brain tumor in human. After standard therapies, that include surgical resection followed by radiotherapy and chemotherapy, it is difficult to completely remove the tumor and the development of relapses and resistance is almost inevitable. The chemotherapy now available also show important side effects, to overcame those limitation, new platinum-based drugs are being synthetized, Pt(IV)Ac-POA, (OC-6-44)-acetate-diamine-chloride(2-(2-propynyl)octanoato)platinum(IV), a prodrug having an Histone-3-DeAcetylase-Inhibitor as axial ligands, is one of them. Moreover, new compounds of plant origin are increasingly seen as potential sources of benefits in oncological treatments. The aim of the study is to investigate the possible contribution of micotherapy in the fight against GBM, its role in the metabolism of reactive oxygen species (ROS) and its synergic effect with a new platinum-based compound, Pt(IV)Ac-POA, on human glioblastoma U251 cells. Through cytofluorimetric and immunofluorescence analysis, the ability of the micotherapy in study to regulate the cell cycle was assessed, and its importance in controlling the cellular redox state was also revealed, opening to the possibility of a new therapy in which micotherapy can support the activity of new chemotherapy while reducing its side effects controlling inflammatory conditions in the microenvironment. Additionally, the combined therapy appeared able to induce regulated form of necrosis, such as ferroptosis, and to hinder the establishment of resistance mechanisms.

Polymeric and small molecule-conjugates of temozolomide as improved therapeutic agents for glioblastoma multiforme

Temozolomide (TMZ), an imidazotetrazine, is a second-generation DNA alkylating agent used as a first-line treatment of glioblastoma multiforme (GBM). It was approved by FDA in 2005 and declared a blockbuster drug in 2008. Although TMZ has shown 100% oral bioavailability and crosses the blood-brain barrier effectively, however it suffers from limitations such as a short half-life (∼1.8 h), rapid metabolism, and lesser accumulation in the brain (∼10-20%). Additionally, development of chemoresistance has been associated with its use. Since it is a potential chemotherapeutic agent with an unmet medical need, advanced delivery strategies have been explored to overcome the associated limitations of TMZ. Nanocarriers including liposomes, solid lipid nanoparticles (SLNs), nanostructure lipid carriers (NLCs), and polymeric nanoparticles have demonstrated their ability to improve its circulation time, stability, tissue-specific accumulation, sustained release, and cellular uptake. Because of the appreciable water solubility of TMZ (∼5 mg/mL), the physical loading of TMZ in these nanocarriers is always challenging. Alternatively, the conjugation approach, wherein TMZ has been conjugated to polymers or small molecules, has been explored with improved outcomes in vitro and in vivo. This review emphasized the practical evidence of the conjugation strategy to improve the therapeutic potential of TMZ in the treatment of glioblastoma multiforme.

Tumor grading model employing geometric analysis of histopathological images with characteristic nuclei dictionary

Histopathological study has been shown to improve diagnosis of various disease classifications effectively as any disease condition is correlated to characteristic set of changes in the tissue structure. This study aims at developing an automated neural network system for grading brain tumors (Glioblastoma Multiforme) from histopathological images within the Whole Slide Images (WSI) of hematoxylin and eosin (H&E) stains with significant accuracy. Hematoxylin channels are extracted from the histopathological image patches using color de-convolution. Cell nuclei are precisely segmented using three level Otsu thresholding. From each segmented image, nuclei boundaries are extracted to extract nucleus level features based on their shape and size. Geometric features including ellipse eccentricities, nucleus perimeter, area, and polygon edge counts are extracted using geometric algorithms to define the nuclei boundaries of the segmented image. These features are collected for a large number of nuclei and the nuclei are clustered using the K-Means algorithm in order to create a dictionary. One of the major contributions involves the creation of dictionary of a fixed number of representative cell nuclei to speed up patch level classification. This optimal dictionary is used for clustering extracted cell nuclei and a fixed length histogram of counts on different types of nuclei is obtained. The proposed system has been tested with a total of 239600 TCGA patches of GBM and 206000 patches of LGG collected from GDC data portal and it showed good diagnosis performance with auto-classification accuracy of 97.2% compared to other state-of-art methods. Our results on segmentation and classification are encouraging, with better attainment with regard to precision and accuracy in contrast with previous models. The auto grading proposed system will act as a potential guide for pathologists to make more accurate decisions.

Early and Bi-hemispheric seizure onset in a rat glioblastoma Multiforme model

GBM is the most life-threatening neurological disease with annual incidence of ∼ 5 cases per 100,000 people and a median survival of less than 15 months. Seizures are the first clinical symptoms in 40%-45% of patients with GBM and its epileptogenic mechanisms are poorly understood, largely due to the challenge to develop a clinically-relevant animal model and the unknown latent period. In this study, we used continuous video-EEG monitoring to detect the earliest interictal and ictal events in a CRISPR- IUE GBM rat model that shares pathological and clinical features with those observed in human patients. To our best knowledge, we showed for the first time that interictal epileptiform discharges emerged during early postnatal weeks and the first ictal event occurred during the fourth postnatal week. We also showed GBM animals showed independent bi-hemispheric epileptogenic events, suggesting a widespread circuitry dysregulation. Together, our work identified the temporal- and spatial frame of epileptogenic network in a highly clinically-relevant GBM animal model, paving ways for mechanistic studies at molecular, cellular and circuitry levels.

Overexpression of c-Met is Associated with Poor Prognosis in Glioblastoma Multiforme: A Systematic Review and Meta-Analyses

Objective:

The aim of this study is to evaluate the association of c-Met overexpression with survival of glioblastoma multiforme (GBM) patients.

Methods:

A systematic review with meta-analyses was conducted on related articles from PubMed, EBSCOhost, Scopus, and Cochrane databases with last updated search on October 31, 2020. A total of 7 studies regarding c-Met overexpression and overall survival (OS) and/or progression free survival (PFS) are included in this study.

Results:

All studies used immunohistochemistry to examine the expression of c-Met protein. The results showed that the positive rate of c-Met overexpression was detected in approximately 33,9% - 60,5% of GBM patients. c-Met overexpression was related to worse OS (HR: 1,74; 95% CI: 1,482-2,043; Z=6,756; p<0,001) and PFS (HR: 1,66; 95% CI: 1,327-2,066; Z=4,464; p<0,001) in GBM patients. Low heterogeneity of subjects was found in both OS and PFS analyses, I² values were 7,8% and 0,0%, respectively.

Conclusion:

In conclusion, c-Met overexpression is significantly related to shorter OS and PFS in GBM patients, so c-Met can be considered as a potential prognostic indicator in GBM.

Exploiting the anticancer effects of a nitrogen bisphosphonate nanomedicine for glioblastoma multiforme

Glioblastoma multiforme (GBM) is an incurable aggressive brain cancer in which current treatment strategies have demonstrated limited survival benefit. In recent years, nitrogen-containing bisphosphonates (N-BPs) have demonstrated direct anticancer effects in a number of tumour types including GBM. In this study, a nano-formulation with the RALA peptide was used to complex the N-BP, alendronate (ALN) into nanoparticles (NPs) < 200 nm for optimal endocytic uptake. Fluorescently labelled AlexaFluor®647 Risedronate was used as a fluorescent analogue to visualise the intracellular delivery of N-BPs in both LN229 and T98G GBM cells. RALA NPs were effectively taken up by GBM where a dose-dependent response was evidenced with potentiation factors of 14.96 and 13.4 relative to ALN alone after 72 h in LN229 and T98G cells, respectively. Furthermore, RALA/ALN NPs at the IC_50, significantly decreased colony formation, induced apoptosis and slowed spheroid growth in vitro. In addition, H-Ras membrane localisation was significantly reduced in the RALA/ALN groups compared to ALN or controls, indicative of prenylation inhibition. The RALA/ALN NPs were lyophilised to enhance stability without compromising the physiochemical properties necessary for functionality, highlighting the suitability of the NPs for scale-up and in vivo application. Collectively, these data show the significant potential of RALA/ALN NPs as novel therapeutics in the treatment of GBM.

4-Acetylantrocamol LT3 Inhibits Glioblastoma Cell Growth and Downregulates DNA Repair Enzyme O6-Methylguanine-DNA Methyltransferase

Glioblastoma multiforme (GBM) is a deadly malignant brain tumor that is resistant to most clinical treatments. Novel therapeutic agents that are effective against GBM are required. Antrodia cinnamomea has shown antiproliferative effects in GBM cells. However, the exact mechanisms and bioactive components remain unclear. Thus, the present study aimed to investigate the effect and mechanism of 4-acetylantrocamol LT3 (4AALT3), a new ubiquinone from Antrodia cinnamomeamycelium, in vitro. U87 and U251 cell lines were treated with the indicated concentration of 4AALT3. Cell viability, cell colony-forming ability, migration, and the expression of proteins in well-known signaling pathways involved in the malignant properties of glioblastoma were then analyzed by CCK-8, colony formation, wound healing, and western blotting assays, respectively. We found that 4AALT3 significantly decreased cell viability, colony formation, and cell migration in both in vitro models. The epidermal growth factor receptor (EGFR), phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR), Hippo/yes-associated protein (YAP), and cAMP-response element binding protein (CREB) pathways were suppressed by 4AALT3. Moreover, 4AALT3 decreased the level of DNA repair enzyme O⁶-methylguanine-DNA methyltransferase and showed a synergistic effect with temozolomide. Our findings provide the basis for exploring the beneficial effect of 4AALT3 on GBM in vivo.

Clinical significance of postoperatif controlling nutritional status (CONUT) score in glioblastoma multiforme

PURPOSE

The Controlling Nutritional Status (CONUT) Score, a new parameter that reflects the immuno-nutritional status, has been closely associated with prognosis in many cancer types. However, the prognostic significance of the CONUT score in Glioblastoma Multiforme (GBM) is not known. In this study, we aimed to show the prognostic significance of the CONUT score in the postoperative period in patients with GBM.

METHODS

120 patients followed up with GBM were included in the study, retrospectively. According to the receiver operating characteristic (ROC) curve analysis, the optimal cut-off values were determined for the CONUT score, and the patients were divided into low (<2.5) and high (≥2.5) CONUT groups. Systemic immune inflammation index (SII), prognostic nutritional index (PNI), and neutrophil-lymphocyte ratio (NLR) were grouped according to the cut-off point of 1111, 46.5, and 4.48, respectively. Cox regression analyzes were used to assess their prognostic significance for progression-free survival (PFS) and overall survival (OS).

RESULTS

The high CONUT score group was found to have worse PFS and OS than the low CONUT score group (p < 0.001, p < 0.001). In univariate analysis, age, gender, comorbidity, CONUT score, SII, PNI, NLR were found to be significant for both PFS and OS. In multivariate analysis, only age and CONUT score were found as independent prognostic factors for both PFS (p: 0.040, p < 0,001) and OS (p: 0,041, p < 0,001).

CONCLUSION

The CONUT score in the postoperative period in patients with GBM is an independent prognostic parameter that predicts progression and survival.

A neuro evolutionary algorithm for patient calibrated prediction of survival in Glioblastoma patients

BACKGROUND AND OBJECTIVES

Glioblastoma multiforme (GBM) is the most common and malignant type of primary brain tumors. Radiation therapy (RT) plus concomitant and adjuvant Temozolomide (TMZ) constitute standard treatment of GBM. Existing models for GBM growth do not consider the effect of different schedules on tumor growth and patient survival. However, clinical trials show that treatment schedule and drug dosage significantly affect patient survival. The goal is to provide a patient calibrated model for predicting survival according to the treatment schedule.

METHODS

We propose a top-down method based on artificial neural networks (ANN) and genetic algorithm (GA) to predict survival of GBM patients. A feed forward undercomplete Autoencoder network is integrated with the neuro-evolutionary (NE) algorithm in order to extract a compressed representation of input clinical data. The proposed NE algorithm uses GA to obtain optimal architecture of a multi-layer perceptron (MLP). Taguchi L₁₆ orthogonal design of experiments is used to tune parameters of the proposed NE algorithm. Finally, the optimal MLP is used to predict survival of GBM patients.

RESULTS

Data from 8 related clinical trials have been collected and integrated to train the model. From 847 evaluable cases, 719 were used for train and validation and the remaining 128 cases were used to test the model. Mean absolute error of the predictions on the test data is 0.087 months which shows excellent performance of the proposed model in predicting survival of the patients. Also, the results show that the proposed NE algorithm is superior to other existing models in both the mean and variability of the prediction error.

Evaluation of Nestin and EGFR in Patients with Glioblastoma Multiforme in a Public Hospital in Iran

Introduction:

Glioblastoma multiforme (GBM) is a grade IV glioma and accounts for 15% of all primary brain tumors. This GBM has a median survival range of less than 2 years after diagnosis and it is highly vascularized by neoformed vessels. Neoangiogenesis is a crucial factor in the malignant tumoral behavior and prognosis of patients and Nestin protein belongs to class VI which is expressed in endothelial cells of neoformed vessels in GBM. Our study shows the correlation between EGFR mutation and Nestin expression in endothelial of neoformed vessels in GBM.

Methods:

We analyzed 40 GBM samples by immunohistochemistry staining. The immunohistochemical expression of EGFR in tumoral cells and Nestin in endothelial cells in paraffin sections were analyzed. EGFR scoring was the based on staining intensity. Score 0 shows No staining, Score1, mild to moderate staining and score2 sever staining. Microvascular density (MVD) was evaluated with Nestin-immunoreactive.

Results:

The mean of MVD was 14.6 ±8.25. Nestin-MVD was significantly higher in GBM with sever vascular prolifration (p-value=0.01). EGFR was expressed in 92.5% of samples. The EGFR scoring for tumoral tissue was 7.5%(score:0), 22.5% (score:1) and 70% (score:2). There was a significant relationship between EGFR expression and MVD (p-value=0.017).

Conclusion:

We suggest that some important mutations as like as EGFR in GBM is responsible for inducing angiogenesis and vascular proliferation. Nestin overexpression as a novel marker might reflect the extent of neoangiogenesis, thus target therapy against EGFR pathway and anti angiogenic may be useful for GBM treatment.

Human Cytomegalovirus (HCMV)-infected Astrocytoma Cells Impair the Function of HCMV-specific Cytotoxic T Cells

BACKGROUND

Human cytomegalovirus (HCMV) infection in glioblastoma multiforme (GBM) is associated with a poor prognosis and may affect the pathogenesis of GBM. In this study, we investigated the role of HCMV-infected astrocytoma cells in impairing the activity of cytotoxic T lymphocytes (CTLs) specific to the HCMV protein.

METHODS

CTLs specific to HCMV immediate early (IE)-1 were expanded from peripheral blood mononuclear cells of healthy donors by stimulating CD8+ T lymphocytes with U373MG cells (ATCC HTB-17: male) expressing HCMV IE-1. The death rate of the target and the effector cells was determined by the total count of the remaining respective cells after the interaction of them.

RESULTS

The death rate of the target cells by CTLs increased depending on HLA restriction and the effector:target (E:T) ratio. The death rate of effector cells in the HCMV-infected U373MG cell culture was 37.1% on day 4 post-infection. The removal of the culture supernatant from HCMV-infected U373MG cells prior to adding the effector cells increased target cell death from 8.4% to 40.8% at E:T = 1:1, but not at E:T = 3:1. The transfer of cells from a 24-hour co-culture of the HCMV-infected U373MG cells and CTLs to HCMV IE-1-expressing target cells resulted in decreasing the cell death rate of the target cells from 31.1% to 13.0% at E:T = 1:1, but not at E:T = 3:1. HCMV infection of U373MG cells decreases the activity of CTLs specific to HCMV when the number of CTLs is low.

CONCLUSION

These results suggest that HCMV could impair CTL activity and facilitate glioblastoma growth unchecked by CTLs.

Drug-induced modifications and modulations of microRNAs and long non-coding RNAs for future therapy against Glioblastoma Multiforme

Non-coding RNAs are known to participate in cancer initiation, progression, and metastasis by regulating the status of chromatin epigenetics and gene expression. Although these non-coding RNAs do not possess defined protein-coding potential, they are involved in the expression and stability of messenger RNA (mRNA). The length of microRNAs (miRs) ranges between 20 and 22 nt, whereas, long non-coding RNAs (lncRNAs) length ranges between 200 nt to 1 Kb. In the case of circular RNAs (circRNAs), the size varies depending upon the length of the exon from where they were derived. Epigenetic regulations of miR and lncRNA genes will influence the gene expression by modulating histone acetylation and methylation patterns. Especially, lncRNAs will act as a scaffold for various epigenetic proteins, such as EZH2 and LSD1, and influence the chromatin epigenetic state at various genomic loci involved at silencing. Thus investigations on the expression of lncRNAs and designing drugs to modulate the expression of these genes will have a profound impact on future therapeutics against cancers such as Glioblastoma Multiforme (GBM) and also against various other diseases. With the recent advancements in genome-wide transcriptomic studies, scientists are focused on the non-coding RNAs and their regulations on various cellular processes involved in GBM and on other types of cancer as well as trying to understand possible epigenetic modulations that help in generating promising therapeutics for the future generations. In this review, the involvement of epigenetic proteins, enzymes that change chromatin architecture and epigenetic landscape and new roles of lncRNAs that are involved in GBM progression are elaborately discussed.

Differential effects of the Akt inhibitor MK-2206 on migration and radiation sensitivity of glioblastoma cells

Background

Most tumor cells show aberrantly activated Akt which leads to increased cell survival and resistance to cancer radiotherapy. Therefore, targeting Akt can be a promising strategy for radiosensitization. Here, we explore the impact of the Akt inhibitor MK-2206 alone and in combination with the dual PI3K and mTOR inhibitor PI-103 on the radiation sensitivity of glioblastoma cells. In addition, we examine migration of drug-treated cells.

Methods

Using single-cell tracking and wound healing migration tests, colony-forming assay, Western blotting, flow cytometry and electrorotation we examined the effects of MK-2206 and PI-103 and/or irradiation on the migration, radiation sensitivity, expression of several marker proteins, DNA damage, cell cycle progression and the plasma membrane properties in two glioblastoma (DK-MG and SNB19) cell lines, previously shown to differ markedly in their migratory behavior and response to PI3K/mTOR inhibition.

Results

We found that MK-2206 strongly reduces the migration of DK-MG but only moderately reduces the migration of SNB19 cells. Surprisingly, MK-2206 did not cause radiosensitization, but even increased colony-forming ability after irradiation. Moreover, MK-2206 did not enhance the radiosensitizing effect of PI-103. The results appear to contradict the strong depletion of p-Akt in MK-2206-treated cells. Possible reasons for the radioresistance of MK-2206-treated cells could be unaltered or in case of SNB19 cells even increased levels of p-mTOR and p-S6, as compared to the reduced expression of these proteins in PI-103-treated samples. We also found that MK-2206 did not enhance IR-induced DNA damage, neither did it cause cell cycle distortion, nor apoptosis nor excessive autophagy.

Conclusions

Our study provides proof that MK-2206 can effectively inhibit the expression of Akt in two glioblastoma cell lines. However, due to an aberrant activation of mTOR in response to Akt inhibition in PTEN mutated cells, the therapeutic window needs to be carefully defined, or a combination of Akt and mTOR inhibitors should be considered.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5517-4) contains supplementary material, which is available to authorized users.

GSK461364A, a Polo-Like Kinase-1 Inhibitor Encapsulated in Polymeric Nanoparticles for the Treatment of Glioblastoma Multiforme (GBM)

Glioblastoma Multiforme (GBM) is a common primary brain cancer with a poor prognosis and a median survival of less than 14 months. Current modes of treatment are associated with deleterious side effects that reduce the life span of the patients. Nanomedicine enables site-specific delivery of active pharmaceutical ingredients and facilitates entrapment inside the tumor. Polo-like kinase 1 (PLK-1) inhibitors have shown promising results in tumor cells. GSK461364A (GSK) is one such targeted inhibitor with reported toxicity issues in phase 1 clinical trials. We have demonstrated in our study that the action of GSK is time dependent across all concentrations. There is a distinct 15−20% decrease in cell viability via apoptosis in U87-MG cells dosed with GSK at low concentrations (within the nanomolar and lower micromolar range) compared to higher concentrations of the drug. Additionally, we have confirmed that PLGA-PEG nanoparticles (NPs) containing GSK have shown significant reduction in cell viability of tumor cells compared to their free equivalents. Thus, this polymeric nanoconstruct encapsulating GSK can be effective even at low concentrations and could improve the effectiveness of the drug while reducing side effects at the lower effective dose. This is the first study to report a PLK-1 inhibitor (GSK) encapsulated in a nanocarrier for cancer applications.

Evaluation of Hydro-Alcoholic Extract of Trifolium Pratens L. for Its Anti-Cancer Potential on U87MG Cell Line

OBJECTIVE

Glioblastoma multiforme is the most malignant form of brain tumors. Trifolium pratense L. has been suggested for cancer treatment in traditional medicine. Here we have investigated the effects of T. pratense extract on glioblastoma multiforme cell line (U87MG).

MATERIALS AND METHODS

In this experimental study, the effect of T. pratense extract on cell viability was investigated using trypan blue staining, MTT assay, and lactate dehydrogenase activity measurement. Apoptosis and autophagy cell death were detected by fluorescent staining. Nitric oxide (No) production was measured using Griess reaction. Expression levels of some apoptotic and autophagic-related genes were detected using real-time polymerase chain reaction (PCR). The combination effects of T. pratense extract and temozolomide (TMZ) were evaluated by calculating the combination index and dose reduction index values.

RESULTS

After treatment with T. pratense extract, the cell viability was significantly reduced in a time- and dosedependent manner (P<0.05). Apoptosis and autophagy of U87MG cells were significantly increased (P<0.05). Also, T. pratense extract significantly decreased NO production (P<0.05) by U87MG cells. Combination of TMZ and T. pratense extract had a synergistic cytotoxic effect.

CONCLUSION

T. pratense showed anti-cancer properties via induction of apoptosis and autophagy cell death.

Hypothyroidism among patients with glioblastoma multiforme

Background: Patients with glioblastoma multiforme (GBM) are prone to various metabolic changes such as hypothyroidism. The present study was planned to assess the frequency of hypothyroidism in these patients. Methods: Fifty-two patients with GBM were included. All of them had been treated by tumor resection followed by cranial irradiation. Thyroid function was assessed by measurement of serum thyroid stimulating hormone (TSH), free thyroxin (FT4), and free triiodothyronine (FT3). Results: There were 33 men and 19 women. The average age was 52.4 ± 12.8 years. Among these, 32 (61%) had normal thyroid function test, whereas 4 (8%) had subclinical hypothyroidism, 5 (10%) had overt primary hypothyroidism, and 11 (21%) had secondary hypothyroidism. Sixteen patients (31%) needed thyroid hormone replacement therapy. Conclusion: Hypothyroidism is relatively prevalent in patients with treated GBM. Regular thyroid function test is advised to aid the introduction of appropriate hormone replacement therapy.

Radiotherapy and Glioma Stem Cells: Searching for Chinks in Cellular Armor

Purpose of the review

Radiation became a pillar of oncologic treatment in the last century and provided a powerful and effective locoregional treatment of solid malignancies. After achieving some of the first cures in lymphomas and skin cancers, it assumed a key role in curative treatment of epithelioid malignancies. Despite success across a variety of histologic types, glioblastoma (GBM), the most common primary brain tumor afflicting adults, remains ultimately resistant to current radiation strategies. While GBMs demonstrate an initial response, recurrence is essentially universal and fatal, and typically reoccur in the areas that received the most intense radiation.

Recent Findings

Glioma stem cells (GSCs), a subpopulation of tumor cells with expression profiles similar to neural stem cells and marked self-renewal capacities, have been shown to drive tumor recurrence and preclude curative radiotherapy. Recent research has shown that these cells have enhanced DNA repair capacity, elevated resistance to cytotoxic ion fluxes and escape multi-modality therapies.

Summary

We will analyze the current understanding of GSCs and radiation by highlighting key discoveries probing their ability to withstand radiotherapy. We then speculate on novel mechanisms by which GSC can be made sensitive to or specifically targeted by radiation therapy.

Enhanced targeting of invasive glioblastoma cells by peptide-functionalized gold nanorods in hydrogel-based 3D cultures

Cancer stem cells (CSCs) are responsible for drug resistance, tumor recurrence, and metastasis in several cancer types, making their eradication a primary objective in cancer therapy. Glioblastoma Multiforme (GBM) tumors are usually composed of a highly infiltrating CSC subpopulation, which has Nestin as a putative marker. Since the majority of these infiltrating cells are able to elude conventional therapies, we have developed gold nanorods (AuNRs) functionalized with an engineered peptide capable of specific recognition and selective eradication of Nestin positive infiltrating GBM-CSCs. These AuNRs generate heat when irradiated by a near-infrared laser, and cause localized cell damage. Nanoparticle internalization assays performed with GBM-CSCs or Nestin negative cells cultured as two-dimensional (2D) monolayers or embedded in three-dimensional (3D) biodegradable-hydrogels of tunable mechanical properties, revealed that the AuNRs were mainly internalized by GBM-CSCs, and not by Nestin negative cells. The AuNRs were taken up via energy-dependent and caveolae-mediated endocytic mechanisms, and were localized inside endosomes. Photothermal treatments resulted in the selective elimination of GBM-CSCs through cell apoptosis, while Nestin negative cells remained viable. Results also indicated that GBM-CSCs embedded in hydrogels were more resistant to AuNR photothermal treatments than when cultured as 2D monolayers. In summary, the combination of our engineered AuNRs with our tunable hydrogel system has shown the potential to provide an in vitro platform for the evaluation and screening of AuNR-based cancer therapeutics, leading to a substantial advancement in the application of AuNRs for targeted GBM-CSC therapy.

STATEMENT OF SIGNIFICANCE

There is an urgent need for reliable and efficient therapies for the treatment of Glioblastoma Multiforme (GBM), which is currently an untreatable brain tumor form with a very poor patient survival rate. GBM tumors are mostly comprised of cancer stem cells (CSCs), which are responsible for tumor reoccurrence and therapy resistance. We have developed gold nanorods functionalized with an engineered peptide capable of selective recognition and eradication of GBM-CSCs via heat generation by nanorods upon NIR irradiation. An in vitro evaluation of nanorod therapeutic activities was performed in 3D synthetic-biodegradable hydrogel models with distinct biomechanical cues, and compared to 2D cultures. Results indicated that cells cultured in 3D were more resistant to photothermolysis than in 2D systems.

Glioblastoma multiforme in patients with history of extracranial cancer: Case series

OBJECTIVES

Significant progress in treatment strategies improves the expectations of patients with extracranial cancers. Metastases are the primary consideration in patients with cancer history. In the case of neurologic disorders, the patient should undergo brain MRI. A rationale is presented for surgery, whole-brain or stereotactic radiotherapy, or chemotherapy. Recently, we have encountered misdiagnosed primary malignant brain tumours in patients with oncologic history who had been admitted for surgery for brain metastases. The aim of our study is to evaluate the incidence of concurrent cancers, to assess the relationship between previous cancer staging and primary brain tumour evaluation as well as to determine treatment efficiency.

METHODS

From January 2007 to December 2011, we prospectively followed up patients with concurrent history of both extracranial cancer and subsequent glioblastoma multiforme. Information was collected on the clinical condition, imaging, history of extracranial cancer, previous and present surgical and oncologic procedures, and GBM histologic, cytogenetic, and molecular genetic investigations.

RESULTS

Five patients were recruited: three females and two males. The average patient age at the time of GBM diagnosis was 65.6 years. Three patients had a history of breast carcinoma, one of renal carcinoma and one of colorectal carcinoma. Following the diagnosis of carcinoma, three patients received chemotherapy and radiotherapy, one patient had radiotherapy alone, and one had no adjuvant therapy. In all the cases, surgery revealed primary GBM, with a standard occurrence of genetic abnormalities (Table 1). The average time from the diagnosis of extracranial cancer to that of GBM was 4 years. Four patients underwent chemoradiotherapy and one had palliative radiotherapy. Two patients completed oncotherapy and their OS was 27 months and 19 months, respectively. One patient had post-surgical progression of hemiparesis. One patient had pulmonary embolism during oncotherapy and one had paraplegia caused by a pathological fracture of vertebras T5 due to breast carcinoma metastases. The OS was 11.8 months (range 3-27 months). All the patients succumbed to GBM progression.

Normalized Apparent Diffusion Coefficient in the Prognostication of Patients with Glioblastoma Multiforme

BACKGROUND

Glioblastoma multiforme (GBM) is known to have poor prognosis, with no available imaging marker that can predict survival at the time of diagnosis. Diffusion weighted images are used in characterisation of cellularity and necrosis of GBM. The purpose of this study was to assess whether pattern or degree of diffusion restriction could help in the prognostication of patients with GBM.

MATERIAL AND METHODS

We retrospectively analyzed 84 consecutive patients with confirmed GBM on biopsy or resection. The study was approved by the institutional ethics committee. The total volume of the tumor and total volume of tumor showing restricted diffusion were calculated. The lowest Apparent Diffusion Coefficient (ADC) in the region of the tumor and in the contralateral Normal Appearing White Matter were calculated in order to calculate the nADC. Treatment and follow-up data in these patients were recorded. Multivariate analsysis was completed to determine significant correlations between different variables and the survival of these patients.

RESULTS

Patient survival was significantly related to the age of the patient (p<0.0001; 95% CI-1.022-1.043) and the nADC value (p=0.014; 95% CI-0.269-0.860) in the tumor. The correlation coefficients of age and nADC with survival were -0.335 (p=0.002) and 0.390 (p<0.001), respectively. Kaplan Meier survival function, grouped by normalized Apparent Diffusion Coefficient cut off value of 0.75, was significant (p=0.007).

CONCLUSION

The survival of patients with GBM had small, but significant, correlations with the patient's age and nADC within the tumor.

Evaluation of Endoglin as an Angiogenesis Marker in Glioblastoma

BACKGROUND AND OBJECTIVES

Angiogenesis is essential for growth and metastasis of solid malignancies. Tumor vessel count and expression of vascular endothelial growth factor (VEGF), a potent angiogenic factor, have been associated with prognosis. This study was designed to assess vessels density by using CD31 and CD105 (Endoglin) and their correlation with expression of VEGF and proliferative index (Ki67) in Glioblastoma multiforme (GBM).

METHODS

We examined these parameters in GBM specimens from 50 adult patients; referred to Al-Zahra hospital Pathology Lab between 2001 to 2006.These patients did not receive pre-operative therapy. Paraffin-embedded tumor specimens were immunohistochemically stained for CD31, CD105 (Endoglin), VEGF and Ki67 (proliferation index) monoclonal antibodies. Microvessel density (MVD) was evaluated by immunostaining for CD31 and CD105.Then the results were compared between the two and also with VEGF receptors and Ki67 index.

RESULTS

CD105-MVD was significantly higher in Glioblastoma compared with peritumoral normal (14.28 vs. 6.68: P=0.012). We did not find such difference for CD31. The mean of CD105-MVD was significantly higher than CD31-MVD in Glioblastoma tissue (P<0.001) although there was a significant positive relationship between them (Pearson's r=0.630 P<0.001).The VEGF scoring for tumoral tissue was 12 % (score:1), 46% (score:2) and 42% (score:3).For peritumoral normal tissue were 92% (score:1) and 8% (score:2) . So they reach to statistical significance (Chi Square, P = 0001). Both MVD of CD105 and CD31 have significant relationship with VEGF (P<0.001).

CONCLUSION

We suggest that Endoglin can be used as a specific and sensitive marker for evaluation of angiogenesis in Glioblastoma.

Complement activation in Glioblastoma multiforme pathophysiology: evidence from serum levels and presence of complement activation products in tumor tissue

Inflammation plays a key role in the pathophysiology of Glioblastoma Multiforme (GBM). Here we focus on the contribution of the so far largely ignored complement system. ELISA and immunohistochemistry were combined to assess levels and localization of critical components of the initiation- and effector pathways of the complement cascade in sera and tumor tissue from GBM patients and matched controls. Serum levels of factor-B were decreased in GBM patients whereas C1q levels were increased. C1q and factor-B deposited in the tumor tissue. Deposition of C3 and C5b-9 suggests local complement activation.MBL deficiency, based on serum levels, was significantly less frequent among GBM patients compared to controls (14% vs. 33%). Therefore low levels of MBL may protect against the initiation/progression of GBM.