Biomarkers of glioblastoma multiforme

Unlocking the code: The role of molecular and genetic profiling in revolutionizing glioblastoma treatment

Glioblastoma (GBM) is the most aggressive primary brain cancer, characterized by profound molecular and cellular heterogeneity, which contributes to its resistance to conventional therapies and poor prognosis. Despite multimodal treatments including surgical resection, radiation, and chemotherapy, median survival remains approximately 15 months. Recent advances in molecular and genetic profiling have elucidated key genetic alterations and molecular subtypes of GBM, such as EGFR amplification, PTEN and ATRX loss, and TP53 alterations, which have significant prognostic and therapeutic implications. These discoveries have spurred the development of targeted therapies aimed at disrupting aberrant signaling pathways like RTK/RAS/PI3K and TP53. However, treatment resistance remains a formidable challenge, driven by tumor heterogeneity, the complex tumor microenvironment (TME), and intrinsic adaptive mechanisms. Emerging therapeutic approaches aim to address these challenges, including the use of immunotherapies such as immune checkpoint inhibitors and CAR T-cell therapies, which target specific tumor antigens but face hurdles due to the immunosuppressive TME. Additionally, novel strategies like biopolymer-based interstitial therapies, focused ultrasound for blood-brain barrier disruption, and nanoparticle-based drug delivery systems show promise in enhancing the efficacy and precision of GBM treatments. This review explores the evolving landscape of GBM therapy, emphasizing the importance of personalized medicine through molecular profiling, the potential of combination therapies, and the need for innovative approaches to overcome therapeutic resistance. Continued research into GBM's biology and treatment modalities offers hope for improving patient outcomes.

Predictive and Prognostic Significance of Molecular Biomarkers in Glioblastoma

Glioblastoma multiforme (GBM), a WHO grade 4 glioma, is the most common and aggressive primary brain tumor, characterized by rapid progression and poor prognosis. The heterogeneity of GBM complicates diagnosis and treatment, driving research into molecular biomarkers that can offer insights into tumor behavior and guide personalized therapies. This review explores recent advances in molecular biomarkers, highlighting their potential to improve diagnosis and treatment outcomes in GBM patients. Key biomarkers such as MGMT promoter methylation, IDH1/2 mutations, EGFR amplification, and TERT promoter mutations, etc., are examined for their roles in prognosis, therapeutic response, and tumor classification. While molecular biomarkers offer valuable insights for tailoring GBM treatments, their clinical application is hindered by tumor heterogeneity, dynamic genetic evolution, and the lack of standardized testing methods. Future research should aim to confirm new biomarkers and incorporate them into regular clinical practice to improve prognosis and treatment choices. Advances in genomic and proteomic technologies, along with consistent biomarker detection, could transform GBM care and enhance patient outcomes.

Hsp70 and Calcitonin Receptor Protein in Extracellular Vesicles from Glioblastoma Multiforme: Biomarkers with Putative Roles in Carcinogenesis and Potential for Differentiating Tumor Types

Glioblastoma multiforme (GBM) is a malignancy of bad prognosis, and advances in early detection and treatment are needed. GBM is heterogenous, with varieties differing in malignancy within a tumor of a patient and between patients. Means are needed to distinguish these GMB forms, so that specific strategies can be deployed for patient management. We study the participation of the chaperone system (CS) in carcinogenesis. The CS is dynamic, with its members moving around the body in extracellular vesicles (EVs) and interacting with components of other physiological systems in health and disease, including GBM. Here, we describe the finding of high amounts of Hsp70 (HSPA1A) and the calcitonin receptor protein (CTR) in EVs in patients with GBM. We present a standardized protocol for collecting, purifying, and characterizing EVs carrying Hsp70 and CTR in plasma-derived EVs from patients with GBM. EVs from GBM patients were obtained just before tumor ablative surgery (T0) and 7 days afterwards (T1); Hsp70 was highly elevated at T0 and less so at T1, and CTR was greatly increased at T0 and reduced to below normal values at T1. Our results encourage further research to assess Hsp70 and CTR as biomarkers for differentiating tumor forms and to determine their roles in GBM carcinogenesis.

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.

COL1A2 inhibition suppresses glioblastoma cell proliferation and invasion

OBJECTIVE

An extracellular matrix such as collagen is an essential component of the tumor microenvironment. Collagen alpha-2(I) chain (COL1A2) is a chain of type I collagen whose triple helix comprises two alpha-1 chains and one alpha-2 chain. The authors' proteomics data showed that COL1A2 is significantly higher in the blood of patients with glioblastoma (GBM) compared with healthy controls. COL1A2 has many different functions in various types of cancers. However, the functions of COL1A2 in GBM are poorly understood. In this study, the authors analyzed the functions of COL1A2 and its signaling pathways in GBM.

METHODS

Surgical specimens and GBM cell lines (T98, U87, and U251) were used. The expression level of COL1A2 was examined using GBM tissues and normal brain tissues by quantitative real-time polymerase chain reaction. The clinical significance of these levels was evaluated using Kaplan-Meier analysis. Small interfering RNA (siRNA) and small hairpin RNA of COL1A2 were transfected into GBM cell lines to investigate the function of COL1A2 in vitro and in vivo. Flow cytometry was introduced to analyze the alteration of cell cycles. Western blot and immunohistochemistry were performed to analyze the underlying mechanisms.

RESULTS

The expression level of COL1A2 was upregulated in GBM compared with normal brain tissues. A higher expression of COL1A2 was correlated with poor progression-free survival and overall survival. COL1A2 inhibition significantly suppressed cell proliferation in vitro and in vivo, likely due to G1 arrest. The invasion ability was notably deteriorated by inhibiting COL1A2. Cyclin D1, cyclin-dependent kinase 1, and cyclin-dependent kinase 4, which are involved in the cell cycle, were all downregulated after blockade of COL1A2 in vitro and in vivo. Phosphoinositide 3-kinase inhibitor reduced the expression of COL1A2. Although downregulation of COL1A2 decreased the protein kinase B (Akt) phosphorylation, Akt activator can phosphorylate Akt in siRNA-treated cells. This finding suggests that Akt phosphorylation is partially dependent on COL1A2.

CONCLUSIONS

COL1A2 plays an important role in driving GBM progression. COL1A2 inhibition attenuated GBM proliferation by promoting cell cycle arrest, indicating that COL1A2 could be a promising therapeutic target for GBM treatment.

Rewired Metabolism of Amino Acids and Its Roles in Glioma Pathology

Amino acids (AAs) are indispensable building blocks of diverse bio-macromolecules as well as functional regulators for various metabolic processes. The fact that cancer cells live with a voracious appetite for specific AAs has been widely recognized. Glioma is one of the most lethal malignancies occurring in the central nervous system. The reprogrammed metabolism of AAs benefits glioma proliferation, signal transduction, epigenetic modification, and stress tolerance. Metabolic alteration of specific AAs also contributes to glioma immune escape and chemoresistance. For clinical consideration, fluctuations in the concentrations of AAs observed in specific body fluids provides opportunities to develop new diagnosis and prognosis markers. This review aimed at providing an extra dimension to understanding glioma pathology with respect to the rewired AA metabolism. A deep insight into the relevant fields will help to pave a new way for new therapeutic target identification and valuable biomarker development.

Gene clusters based on OLIG2 and CD276 could distinguish molecular profiling in glioblastoma

Background

The molecular profiling of glioblastoma (GBM) based on transcriptomic analysis could provide precise treatment and prognosis. However, current subtyping (classic, mesenchymal, neural, proneural) is time-consuming and cost-intensive hindering its clinical application. A simple and efficient method for classification was imperative.

Methods

In this study, to simplify GBM subtyping more efficiently, we applied a random forest algorithm to conduct 26 genes as a cluster featured with hub genes, OLIG2 and CD276. Functional enrichment analysis and Protein–protein interaction were performed using the genes in this gene cluster. The classification efficiency of the gene cluster was validated by WGCNA and LASSO algorithms, and tested in GSE84010 and Gravandeel’s GBM datasets.

Results

The gene cluster (n = 26) could distinguish mesenchymal and proneural excellently (AUC = 0.92), which could be validated by multiple algorithms (WGCNA, LASSO) and datasets (GSE84010 and Gravandeel’s GBM dataset). The gene cluster could be functionally enriched in DNA elements and T cell associated pathways. Additionally, five genes in the signature could predict the prognosis well (p = 0.0051 for training cohort, p = 0.065 for test cohort).

Conclusions

Our study proved the accuracy and efficiency of random forest classifier for GBM subtyping, which could provide a convenient and efficient method for subtyping Proneural and Mesenchymal GBM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03083-y.

Large-Scale Transcriptomics-Driven Approach Revealed Overexpression of CRNDE as a Poor Survival Prognosis Biomarker in Glioblastoma

Glioblastoma is the most common and malignant brain malignancy worldwide, with a 10-year survival of only 0.7%. Aggressive multimodal treatment is not enough to increase life expectancy and provide good quality of life for glioblastoma patients. In addition, despite decades of research, there are no established biomarkers for early disease diagnosis and monitoring of patient response to treatment. High throughput sequencing technologies allow for the identification of unique molecules from large clinically annotated datasets. Thus, the aim of our study was to identify significant molecular changes between short- and long-term glioblastoma survivors by transcriptome RNA sequencing profiling, followed by differential pathway-activation-level analysis. We used data from the publicly available repositories The Cancer Genome Atlas (TCGA; number of annotated cases = 135) and Chinese Glioma Genome Atlas (CGGA; number of annotated cases = 218), and experimental clinically annotated glioblastoma tissue samples from the Institute of Pathology, Faculty of Medicine in Ljubljana corresponding to 2-58 months overall survival (n = 16). We found one differential gene for long noncoding RNA CRNDE whose overexpression showed correlation to poor patient OS. Moreover, we identified overlapping sets of congruently regulated differential genes involved in cell growth, division, and migration, structure and dynamics of extracellular matrix, DNA methylation, and regulation through noncoding RNAs. Gene ontology analysis can provide additional information about the function of protein- and nonprotein-coding genes of interest and the processes in which they are involved. In the future, this can shape the design of more targeted therapeutic approaches.

Scientific and Clinical Challenges within Neuro-Oncology

Both primary and metastatic brain tumors carry poor prognoses despite modern advances in medical therapy, radiation therapy, and surgical techniques. Gliomas, including glioblastoma (GBM), are particularly difficult to treat, and high-grade gliomas have poor outcomes. Treatment of brain tumors involves a unique set of scientific and clinical challenges, which are often not present in the treatment of systemic malignancies. With respect to scientific challenges, the anatomy and physiology of brain tumors (including the blood-brain barrier, blood-tumor barrier, and blood-cerebrospinal fluid barrier) prevent adequate drug delivery into the central nervous system. The unique nature of the immune system in the central nervous system as well as the immunosuppressive microenvironment of tumors such as GBM also create therapeutic roadblocks in the treatment of brain tumors. Tumor heterogeneity, particularly in GBM, has classically been believed to contribute to multitherapy resistance; however, recent data suggest that this may not be the case. Clinical challenges include neurologic and medical comorbidities of patients with brain tumor, as well as potential toxicity of tumor-directed treatment. Clinical trials investigating new treatment paradigms are needed, but several roadblocks exist to good and promising clinical trial availability.

ELTD1 as a multi-focal target for malignant gliomas: preclinical studies

BACKGROUND

Glioblastoma (GBM) is the most aggressive malignant primary brain tumor in adults. These high-grade gliomas undergo unregulated vascular angiogenesis, migration and cell proliferation allowing the tumor cells to evade cell-cycle checkpoints and apoptotic pathways. The Epidermal growth factor, latrophilin, and seven transmembrane domain-containing 1 on chromosome 1 (ELTD1) is an angiogenic biomarker that is highly expressed in malignant gliomas. Novel treatments targeting ELTD1 with monovalent monoclonal (mmAb) and single chain variable fragment (scFv) antibodies were effective in increasing animal survival, decreasing tumor volume and normalizing the vasculature. Due to the success of our antibody treatments on angiogenesis, this study sought to determine if our anti-ELTD1 treatments affected other aspects of tumorigenesis (cell proliferation, migration, and apoptosis) in a G55 glioma xenograft preclinical mouse model.

METHODS

Tumor tissue from untreated, mmAb and scFv anti-ELTD1 treated animals was used to quantify the positivity levels of human mitochondrial antibody, c-MET and Ki-67 for cellular proliferation, migratory markers CD44v6, TRPM8, and BMP2, and cleaved caspase 3 to assess apoptotic activity.

RESULTS

This approach demonstrated that our anti-ELTD1 treatments directly affected and decreased the human tumor cells within the tumor region. Additionally, there was a significant decrease in both cellular proliferation and migration due to anti-ETLD1 therapy. Lastly, anti-ELTD1 treatments successfully increased apoptotic activity within the tumor region.

CONCLUSION

Our data suggest that anti-ELTD1 therapies would be effective against malignant gliomas by having a multi-focal effect and targeting all four aspects of tumorigenesis.

Advanced magnetic resonance imaging to support clinical drug development for malignant glioma

Even though the treatment options and survival of patients with glioblastoma multiforme (GBM), the most common type of malignant glioma, have improved over the past decade, there is still a high unmet medical need to develop novel therapies. Complexity in pathology and therapy require biomarkers to characterize tumors, to define malignant and active areas, to assess disease prognosis, and to quantify and monitor therapy response. While conventional magnetic resonance imaging (MRI) techniques have improved these assessments, limitations remain. In this review, we evaluate the role of various non-invasive biomarkers based on advanced structural and functional MRI techniques in the context of GBM drug development over the past 5 years.

Overexpression of LncRNA PSMG3-AS1 Distinguishes Glioblastomas from Sarcoidosis

In clinical practices, glioblastomas (GBM) in some cases can be misdiagnosed as sarcoidosis. This study aimed to develop a biomarker to distinguish GBM from sarcoidosis. In this study, we found that PSMG3-AS1 was upregulated in plasma of GBM patients in comparison with that in sarcoidosis patients and healthy controls. Receiver operating characteristic (ROC) curve analysis showed that upregulation of PSMG3-AS1 effectively separated GBM patients from sarcoidosis patients and healthy controls. In GBM cells, overexpression of PSMG3-AS1 led to downregulated miR-34a and increased methylation of miR-34a gene. In addition, overexpression of PSMG3-AS1 reduced the inhibitory effects of miR-34a on GBM cell proliferation. In conclusion, overexpression of PSMG3-AS1 distinguishes GBM patients from patients with sarcoidosis, and PSMG3-AS1 may promote GBM cell proliferation by downregulating miR-34a through methylation.

Expression Of Cyclin D1 Protein Isoforms And Its Prognostic Significance In Cervical Cancer

Introduction

Cyclin D1 had been associated with different clinical and pathological stages of cervical cancer; however, few studies had focused on its correlation with cervical cancer prognosis. Therefore, this study aimed to assess the expression of cyclin D1a and D1b in normal tissue, cervical cancer and cervical intraepithelial neoplasia and their effect on prognosis.

Methods

Expression of cyclin D1a and D1b was detected by immunohistochemical staining in 78 cases of primary cervical cancer, 40 cases of cervical intraepithelial neoplasia, and 40 cases of normal cervical tissue.

Results

No significant difference was observed in the expression of cyclin D1a between normal and cervical cancer tissues (P = 0.201); however, its expression was significantly higher in cervical cancer than in cervical intraepithelial neoplasia tissues (P = 0.000). Expression of cyclin D1b was higher in normal tissues than in cervical cancer tissues (P = 0.000). No significant difference was observed in the expression of cyclin D1a in cervical cancer tissues with respect to age, pathological type, clinical-stage, depth of tumor invasion, or presence of lymph node metastases (P = 0.111,0.119,0.539,0.084,0.539). COX survival analysis showed that lymph node metastasis might be an independent factor affecting postoperative recurrence (hazard risk [HR] = 0.240; 95% confidence interval [CI] = 0.968–30.156; P = 0.034).

Discussion

Cyclin D1a expression was associated with tumor tissue size and degree of differentiation. The expression of cyclin D1b in cervical cancer was associated with the presence of lymph node metastases. Cyclin D1a and D1b expression in cervical cancer tissue was significantly correlated. Cox survival analysis showed that the presence of lymph node metastases might serve as an independent factor affecting postoperative recurrence. The expression of cyclin D1a and D1b was not associated with cervical cancer prognosis.

Conclusion

Assessment of cyclin D1a and D1b expression in cervical cancer and cervical intraepithelial neoplasia revealed that cyclin D1 could not be used as a reference to assess cervical cancer patient prognosis.

High Expression of PTPN3 Predicts Progression and Unfavorable Prognosis of Glioblastoma

Background

PTPN3 was demonstrated to be involved in the progression of several types of cancers, such as gastric adenocarcinoma, lung cancer, and intrahepatic cholangiocarcinoma. However, its clinical significance in glioblastoma (GBM) has not been elucidated.

Material/Methods

We investigated the expression of PTPN3 in 95 cases of GBM with immunohistochemistry and in 8 pairs of fresh GBMs and their adjacent tissues with qualitative polymerase chain reaction. Moreover, the correlation between PTPN3 and clinicopathological factors was evaluated by chi-square test. The prognostic value of PTPN3 was investigated with univariate analysis and multivariate analysis. With MTT assay and Transwell assay, the oncogenic functions of PTPN3 in GBM proliferation and invasion were further investigated.

Results

Expression of PTPN3 in GBM tissues was significantly higher than in their corresponding adjacent tissues. High expression of PTPN3 was significantly associated with unfavorable prognosis of GBM. Moreover, in GBM cell lines, PTPN3 promoted cell proliferation and invasion, and the PTP common inhibitor pervanadate suppressed GBM proliferation and invasion.

Conclusions

Our experiments show that PTPN3 is an independent prognostic factor in GBM and indicated that postoperative detection of PTPN3 can be used to identify high-risk patients and guide individual treatment.

Pharmacometabolomics Informs Quantitative Radiomics for Glioblastoma Diagnostic Innovation

Applications of omics systems biology technologies have enormous promise for radiology and diagnostics in surgical fields. In this context, the emerging fields of radiomics (a systems scale approach to radiology using a host of technologies, including omics) and pharmacometabolomics (use of metabolomics for patient and disease stratification and guiding precision medicine) offer much synergy for diagnostic innovation in surgery, particularly in neurosurgery. This synthesis of omics fields and applications is timely because diagnostic accuracy in central nervous system tumors still challenges decision-making. Considering the vast heterogeneity in brain tumors, disease phenotypes, and interindividual variability in surgical and chemotherapy outcomes, we believe that diagnostic accuracy can be markedly improved by quantitative radiomics coupled to pharmacometabolomics and related health information technologies while optimizing economic costs of traditional diagnostics. In this expert review, we present an innovation analysis on a systems-level multi-omics approach toward diagnostic accuracy in central nervous system tumors. For this, we suggest that glioblastomas serve as a useful application paradigm. We performed a literature search on PubMed for articles published in English between 2006 and 2016. We used the search terms "radiomics," "glioblastoma," "biomarkers," "pharmacogenomics," "pharmacometabolomics," "pharmacometabonomics/pharmacometabolomics," "collaborative informatics," and "precision medicine." A list of the top 4 insights we derived from this literature analysis is presented in this study. For example, we found that (i) tumor grading needs to be better refined, (ii) diagnostic precision should be improved, (iii) standardization in radiomics is lacking, and (iv) quantitative radiomics needs to prove clinical implementation. We conclude with an interdisciplinary call to the metabolomics, pharmacy/pharmacology, radiology, and surgery communities that pharmacometabolomics coupled to information technologies (chemoinformatics tools, databases, collaborative systems) can inform quantitative radiomics, thus translating Big Data and information growth to knowledge growth, rational drug development and diagnostics innovation for glioblastomas, and possibly in other brain tumors.

Predicting the cell death responsiveness and sensitization of glioma cells to TRAIL and temozolomide

Genotoxic chemotherapy with temozolomide (TMZ) is a mainstay of treatment for glioblastoma (GBM); however, at best, TMZ provides only modest survival benefit to a subset of patients. Recent insight into the heterogeneous nature of GBM suggests a more personalized approach to treatment may be necessary to overcome cancer drug resistance and improve patient care. These include novel therapies that can be used both alone and with TMZ to selectively reactivate apoptosis within malignant cells. For this approach to work, reliable molecular signatures that can accurately predict treatment responsiveness need to be identified first. Here, we describe the first proof-of-principle study that merges quantitative protein-based analysis of apoptosis signaling networks with data- and knowledge-driven mathematical systems modeling to predict treatment responsiveness of GBM cell lines to various apoptosis-inducing stimuli. These include monotherapies with TMZ and TRAIL, which activate the intrinsic and extrinsic apoptosis pathways, respectively, as well as combination therapies of TMZ+TRAIL. We also successfully employed this approach to predict whether individual GBM cell lines could be sensitized to TMZ or TRAIL via the selective targeting of Bcl-2/Bcl-xL proteins with ABT-737. Our findings suggest that systems biology-based approaches could assist in personalizing treatment decisions in GBM to optimize cell death induction.

miR-202 inhibits the progression of human cervical cancer through inhibition of cyclin D1

The human cervical cancer (CC) acts as the most common one of women tumors. However, the pathological changes and molecular alterations of CC are not clear. It has been reported that miR-202 takes part in the development and progression of different tumors. The present study aims to detect the expression of miR-202 in 100 cases of CC tissues and cells, and then we continued to investigate the potential mechanisms of miR-202 in CC cells. In this work, we found that the expression of miR-202 is obviously decreased in both CC cell lines and tissues, and negatively related with the expression of cyclin D1 in SiHa, HeLa and Caski cells. In-vitro assay revealed that the ectopic expression of miR-202 suppressed the proliferation, migration and invasion of SiHa and HeLa cells. Additionally, the over-expression of miR-202 extremely affected the expression of cyclin D1 protein. Notably, the over-expression of cyclin D1 in SiHa and HeLa cells with miR-202 mimics attenuated the inhibitory effects of miR-202 on cell proliferation, migration and invasion. In conclusion, our study identified that miR-202 plays an important role in regulating cell proliferation, migration and invasion of CC by directly targeting cyclin D1, thus miR-202 may represent a potential therapeutic target for patients with cervical cancer.

miR-204 suppresses the development and progression of human glioblastoma by targeting ATF2

In human cancers, miRNAs are important regulators of multiple cellular processes, and aberrant miRNA expression has been observed, and their alterations contribute to multiple cancer development and progression. Till now, little has been known about the role of miR-204 in human glioblastoma (GBM). In the present study, we used in-vitro assays to investigate the mechanisms of miR-204 in GBM cell lines and 60 cases of GBM tissues. Here, we found that miR-204 expression is downregulated in both GBM cell lines A172, U87 and U251 cells and GBM tissues as compared with NHA cells and normal tissues (all p<0.001). In addition, the ectopic expression of miR-204 suppressed A172 and U87 cell proliferation, migration and invasion. Meanwhile, miR-204 over-expression extremely inhibited the protein expression of ATF2. Notably, the enforced expression of ATF2 in A172 and U87 cells with the over-expression of miR-204 attenuated the inhibitory effects of miR-204 on proliferation, migration and invasion. In conclusion, our findings suggest that miR-204 suppressed cell proliferation, migration and invasion through inhibition of ATF2, thus, miR-204 may function as a useful drug target in the treatment and diagnosis of GBM.

Using NMR in saliva to identify possible biomarkers of glioblastoma and chronic periodontitis

Nowadays there is increasing interest in identifying–and using–metabolites that can be employed as biomarkers for diagnosing, treating and monitoring diseases. Saliva and NMR have been widely used for this purpose as they are fast and inexpensive methods. This case-control study aimed to find biomarkers that could be related to glioblastoma (GBL) and periodontal disease (PD) and studied a possible association between GBL and periodontal status. The participants numbered 130, of whom 10 were diagnosed with GBL and were assigned to the cases group, while the remaining 120 did not present any pathology and were assigned to the control group. On one hand, significantly increased (p < 0.05) metabolites were found in GBL group: leucine, valine, isoleucine, propionate, alanine, acetate, ethanolamine and sucrose. Moreover, a good tendency to separation between the two groups was observed on the scatterplot of the NMR. On the other hand, the distribution of the groups attending to the periodontal status was very similar and we didn´t find any association between GBL and periodontal status (Chi-Square 0.1968, p = 0.91). Subsequently, the sample as a whole (130 individuals) was divided into three groups by periodontal status in order to identify biomarkers for PD. Group 1 was composed of periodontally healthy individuals, group 2 had gingivitis or early periodontitis and group 3 had moderate to advanced periodontitis. On comparing periodontal status, a significant increase (p < 0.05) in certain metabolites was observed. These findings along with previous reports suggest that these could be used as biomarkers of a PD: caproate, isocaproate+butyrate, isovalerate, isopropanol+methanol, 4 aminobutyrate, choline, sucrose, sucrose-glucose-lysine, lactate-proline, lactate and proline. The scatter plot showed a good tendency to wards separation between group 1 and 3.

Current and emerging EGFR therapies for glioblastoma

Glioblastomas (GBMs) are the most lethal and hard to treat malignancies in clinical practice. The standard of care for treating GBM involving surgery and adjuvant radiotherapy and concomitant temozolomide (TMZ) has remained virtually unchanged in the past decade. Molecular targeted therapies against cancer-specific structures have reported mediocre results in the treatment of GBM, due to multiple factors such as the presence of the blood brain barrier or a vast array of molecular alterations which greatly hinder the action of the most therapeutic agents. One such therapy is directed against the epidermal growth factor (EGF) and its' receptor (EGFR) using either monoclonal antibodies or tyrosine kinase inhibitors. Even though anti-EGF/EGFR treatment produced encouraging results in other forms of cancer it failed to present any clinical benefit for patients with GBM. Lately, immunotherapies that focus on using the host's own immune system against cancer cells have gained popularity, with approaches like peptide vaccination being successfully used in clinical trials for different types of malignancies. These immune-based therapies could hold the key to improving both the prognosis and quality of life for patients suffering for cancers previously considered incurable, such as GBM.

Molecular Determinants of Malignant Brain Cancers: From Intracellular Alterations to Invasion Mediated by Extracellular Vesicles

Malignant glioma cells invade the surrounding brain parenchyma, by migrating along the blood vessels, thus promoting cancer growth. The biological bases of these activities are grounded in profound alterations of the metabolism and the structural organization of the cells, which consequently acquire the ability to modify the surrounding microenvironment, by altering the extracellular matrix and affecting the properties of the other cells present in the brain, such as normal glial-, endothelial- and immune-cells. Most of the effects on the surrounding environment are probably exerted through the release of a variety of extracellular vesicles (EVs), which contain many different classes of molecules, from genetic material to defined species of lipids and enzymes. EV-associated molecules can be either released into the extracellular matrix (ECM) and/or transferred to neighboring cells: as a consequence, both deep modifications of the recipient cell phenotype and digestion of ECM components are obtained, thus causing cancer propagation, as well as a general brain dysfunction. In this review, we first analyze the main intracellular and extracellular transformations required for glioma cell invasion into the brain parenchyma; then we discuss how these events may be attributed, at least in part, to EVs that, like the pawns of a dramatic chess game with cancer, open the way to the tumor cells themselves.

Long non-coding RNA PAR5 inhibits the proliferation and progression of glioma through interaction with EZH2

Emerging evidence suggests that long non-coding RNAs (lncRNAs) may be involved in modulating various aspects of tumor biology and serve as potential therapeutic targets as well as novel biomarkers in the treatment of glioma. The present study investigated the role of lncRNA, Prader Willi/Angelman region RNA 5 (PAR5; also known as PWAR5), in glioma and its clinical significance in glioma cases. The expression levels of PAR5 were determined in clinical samples and U87, U251 cells using real-time reverse transcription quantitative polymerase chain reaction (qRT-PCR) analysis. The effects of PAR5 on cell proliferation, migration and invasion were determined using in vitro assays. RNA immunoprecipitation (RIP) and RNA pull-down assays, as well as the evauation of the expression of various oncogenes were carried out to reveal the underlying mechanisms. We found that PAR5 was significantly downregulated in glioma tissues and cell lines. Furthermore, PAR5 expression was negatively correlated with tumor size, World Health Organization (WHO) grade and Karnofsky performance score (KPS). Patients with low PAR5 expression in tumors had a worse overall survival compared to those with higher expression. Finally, in vitro restoration of PAR5 expression inhibited human glioma cell proliferation, invasion and migration by binding to EZH2 and regulating oncogene expression. This finding may provide a therapeutic approach for the future treatment of glioma.

Tissue microarray analysis for epithelial membrane protein-2 as a novel biomarker for gliomas

Epithelial membrane protein-2 (EMP2) expression is noted in many human cancers. We evaluated EMP2 as a biomarker in gliomas. A large tissue microarray of lower grade glioma (WHO grades II-III, n = 19 patients) and glioblastoma (GBM) (WHO grade IV, n = 50 patients) was stained for EMP2. EMP2 expression was dichotomized to low or high expression scores and correlated with clinical data. The mean EMP2 expression was 1.68 in lower grade gliomas versus 2.20 in GBMs (P = 0.01). The percentage of samples with high EMP2 expression was greater in GBMs than lower grade gliomas (90.0 vs. 52.6%, P = 0.001). No significant difference was found between median survival among patients with GBM tumors exhibiting high EMP2 expression and survival of those with low EMP2 expression (8.38 vs. 10.98 months, P = 0.39). However, EMP2 expression ≥2 correlated with decreased survival (r = -0.39, P = 0.001). The EMP2 expression level also correlated with Ki-67 positivity (r = 0.34, P = 0.008). The mortality hazard ratio for GBM patients with EMP2 score of 3 or higher was 1.92 (CI 0.69-5.30). Our findings suggest that elevated EMP2 expression is associated with GBM. With other biomarkers, EMP2 may have use as a molecular target for the diagnosis and treatment of gliomas.

MiR-205 serves as a prognostic factor and suppresses proliferation and invasion by targeting insulin-like growth factor receptor 1 in human cervical cancer

MicroRNAs are a kind of small and non-coding RNAs, which have been demonstrated to play an important role in the progression of human cervical cancer. Here, we found that the expression of miR-205 was low in cervical cancer cell lines and tissues, compared with matched non-tumor tissues and human endocervical epithelial cells. Also, miR-205 was inversely correlated with histological differentiation, metastasis, International Federation of Gynecology and Obstetrics stage, and the expression of insulin-like growth factor receptor 1 messenger RNA and protein. Besides, miR-205 or insulin-like growth factor receptor 1 expression is an independent prognostic factor. Mechanically, ectopic expression of miR-205 decreased proliferation, colony formation, and some proliferation/apoptosis-related proteins in cervical cancer cells. Ectopic expression of miR-205 caused G1 arrest. Luciferase reporter assays confirmed that binding of miR-205 to the 3' untranslated region of insulin-like growth factor receptor 1 may potentially decrease the expression of insulin-like growth factor receptor 1. Notably, insulin-like growth factor receptor 1 overexpression attenuated the inhibitory effects of miR-205 on cell proliferation and invasion, while small interfering RNA-insulin-like growth factor receptor 1 enhanced the inhibitory effects of miR-205 on cell proliferation and invasion. In conclusion, our findings suggested that miR-205 serves as a prognostic factor and suppresses proliferation and invasion by targeting insulin-like growth factor receptor 1 in human cervical cancer. Thus, miR-205/insulin-like growth factor receptor 1 pathway may be of great benefit to cervical cancer patients.

Identifying survival-associated modules from the dysregulated triplet network in glioblastoma multiforme

BACKGROUND

Long noncoding RNAs (lncRNAs) can act as competitive endogenous RNAs (ceRNAs) to compete with mRNAs for binding miroRNAs (miRNAs). The dysregulated triplets, composed by mRNAs, lncRNAs, and miRNAs, contributed to the development and progression of diseases, such as cancer. However, the roles played by triplet biomarkers are not fully understand in glioblastoma multiforme (GBM) patient survival.

OBJECTIVES

Here, we constructed a differential triplet interaction network (TriNet) between GBM and normal tissues and identified GBM survival related triplets.

METHODS

Four significantly dysregulated modules, enriched differentially expressed molecules, were identified by integrating affinity propagation method and hypergeometric method. Furthermore, knockdown of TP73-AS1 was implemented by siRNA and the expression of RFX1 was examined in U87 cells by qRT-PCR. The apoptosis of U87 cells was investigated using MTT assay and Acridine orange/Ethidium bromide (AO/EB) assay.

RESULTS

We randomly split GBM samples into training and testing sets, and found that these four modules can robustly and significantly distinguish low- and high-survival patients in both two sets. By manually curated literatures for triplets mediated by core interactions, we found that members involved tumor invasion, proliferation, and migration. The dysregulated triplets may cause the poor survival of GBM patients. We finally experimentally verified that knockdown of TP73-AS1, an lncRNA of one triplet, could not only reduce the expression of RFX1, an mRNA of this triplet, but also induce apoptosis in U87 cells.

CONCLUSIONS

These results can provide further insights to understand the functions of triplet biomarkers that associated with GBM prognosis.

Inhibitor of Nicotinamide Phosphoribosyltransferase Sensitizes Glioblastoma Cells to Temozolomide via Activating ROS/JNK Signaling Pathway

Overcoming temozolomide (TMZ) resistance is a great challenge in glioblastoma (GBM) treatment. Nicotinamide phosphoribosyltransferase (NAMPT) is a rate-limiting enzyme in the biosynthesis of nicotinamide adenine dinucleotide and has a crucial role in cancer cell metabolism. In this study, we investigated whether FK866 and CHS828, two specific NAMPT inhibitors, could sensitize GBM cells to TMZ. Low doses of FK866 and CHS828 (5 nM and 10 nM, resp.) alone did not significantly decrease cell viability in U251-MG and T98 GBM cells. However, they significantly increased the antitumor action of TMZ in these cells. In U251-MG cells, administration of NAMPT inhibitors increased the TMZ (100 μM)-induced apoptosis and LDH release from GBM cells. NAMPT inhibitors remarkably enhanced the activities of caspase-1, caspase-3, and caspase-9. Moreover, NAMPT inhibitors increased reactive oxygen species (ROS) production and superoxide anion level but reduced the SOD activity and total antioxidative capacity in GBM cells. Treatment of NAMPT inhibitors increased phosphorylation of c-Jun and JNK. Administration of JNK inhibitor SP600125 or ROS scavenger tocopherol with TMZ and NAMPT inhibitors substantially attenuated the sensitization of NAMPT inhibitor on TMZ antitumor action. Our data indicate a potential value of NAMPT inhibitors in combined use with TMZ for GBM treatment.

Concurrent Expression of VEGF-C and Neuropilin-2 Is Correlated with Poor Prognosis in Glioblastoma

Vascular endothelial growth factor-C (VEGF-C) is a secreted growth factor involved in many oncogenic processes, and neuropilin-2 (NRP2) is essential for neuronal guidance as a well-acknowledged co-receptor of VEGF receptors. The overexpression of NRP2 has been reported in many types of cancers, but the significance of NRP2 in glioblastoma is not elucidated. To investigate the clinical significance of VEGF-C and NRP2 in glioblastoma, we detected their expression in 86 cases of glioblastoma with immunohistochemistry and categorized our cohort into high- and low-expression groups according to the immunohistochemistry score, which was the product of the score of staining intensity multiplied by the score reflecting the percentage of positive cells. The proportion of glioblastoma with high VEGF-C expression was 34.9% (30/86), and that with high NRP2 expression was 37.2% (32/86). The proportion of glioblastoma with high expression of both VEGF-C and NRP2 was 15.1% (13/86). Moreover, the proportion of cases with high VEGF-C and low NRP2 was 19.7% (17/86), while the proportion of cases with low VEGF-C and high NRP2 was 22.1% (19/86). The high expression of both VEGF-C and NRP2 was associated with poorer survival rate (P = 0.023), and can be identified as an independent prognostic factor in glioblastoma (P = 0.030). Moreover, cases with low NRP2 expression are easier for complete tumor resection (P = 0.038). In conclusion, the concurrent high expression of VEGF-C and NRP2 is predictive of the unfavorable prognosis in glioblastoma, indicating that the VEGF-C-NRP2 signaling pathway is a potential and promising drug target in glioblastoma therapy.

Prognostic Value of YKL-40 in Patients with Glioblastoma: a Systematic Review and Meta-analysis

YKL-40 is the most highly expressed gene in glioblastoma compared with normal brain tissues. Previous studies assessing the association between YKL-40 and survival in glioblastoma patients reported varying magnitude of estimates. The objective of this meta-analysis was to determine the prognostic value of YKL-40 in glioblastoma patients. PubMed and Embase databases were searched for studies relating to YKL-40 and prognosis of glioblastoma patients. Studies reporting estimates for overall survival by YKL-40 expression in glioblastoma patients were considered eligible. A meta-analysis of included studies was performed using fixed- or random-effect model to calculate the pooled hazard ratio (HR) and 95 % confidence interval (95%CI). Eight studies were ultimately considered eligible and included into the meta-analysis. Those eight studies included 1241 glioblastoma patients. Meta-analysis of those studies showed that high YKL-40 expression was associated with worse overall survival in glioblastoma patients (HR = 1.46, 95%CI 1.33-1.61, P < 0.001). Meta-analysis of studies with adjusted estimates and high quality showed that high YKL-40 expression was independently associated with worse overall survival in glioblastoma patients (HR = 1.50, 95%CI 1.35-1.66, P < 0.001). Both subgroup analysis and sensitivity analysis validated the obvious association between high YKL-40 expression and worse overall survival in glioblastoma patients. High YKL-40 expression is independently and markedly associated with worse overall survival in glioblastoma patients. YKL-40 is a good predictive biomarker of prognosis in glioblastoma patients.

Expression of MECOM is associated with unfavorable prognosis in glioblastoma multiforme

Background

MDS1 and EVI1 complex locus protein EVI1 (MECOM) is an oncogenic transcription factor in several kinds of cancers. However, the clinical significance of MECOM in glioblastoma multiforme (GBM) has not been well elucidated.

Patients and methods

Our study enrolled 86 resected samples of GBM in three medical centers. We detected the expression of MECOM in all the 86 samples by immunohistochemistry and compared the difference of MECOM mRNA between tumor tissues and adjacent tissues with real-time polymerase chain reaction. With immunoblotting, we detected the MECOM expression in different GBM cell lines. Moreover, we analyzed the correlation between MECOM expression and clinicopathologic factors with chi-square test, and evaluated the prognostic value of MECOM with univariate and multivariate analysis.

Results

In GBM tissue, the percentage of MECOM high expression is 41.9% (36/86). The mRNA of MECOM in tumor tissues is remarkably higher than that in adjacent tissues, indicating the oncogenic role of MECOM in GBM. MECOM exists in all the detected cell lines with different abundance. Moreover, MECOM is correlated with poorer overall survival rate (P=0.033) and can be identified as an independent prognostic factor in GBM (P=0.042).

Conclusion

MECOM could be considered as an independent prognostic factor in GBM, predicting it as a potential and promising molecular drug target.

Epidermal growth factor, latrophilin, and seven transmembrane domain-containing protein 1 marker, a novel angiogenesis marker

Epidermal growth factor, latrophilin, and seven transmembrane domain-containing protein 1 on chromosome 1 (ELTD1), an orphan adhesion G-protein coupled receptor, was reported as a regulator of angiogenesis, also involved in cancer progression and development. More recently, ELTD1 was identified as a potential new tumor marker for high-grade glioma. ELTD1, belongs to the G-protein coupled receptor superfamily that comprises the biggest receptor family in the human genome. Following the discovery of ELTD1 almost a decade ago, only a few research groups have attempted to find its role in normal and tumor cells, important information about this receptor remaining still unknown. The ELTD1 ligand has not currently been identified and intracellular signaling studies have not yet been performed in normal or tumor cells. Although the current published data on ELTD1 function and structure are rather limited, this receptor seems to be very important, not only as biomarker, but also as molecular target in glioblastoma. This review summarizes and discusses the current knowledge on ELTD1 structure, function, and its role in both physiological and tumoral angiogenesis.

SIRT6 suppresses glioma cell growth via induction of apoptosis, inhibition of oxidative stress and suppression of JAK2/STAT3 signaling pathway activation

Sirtuin 6 (SIRT6) is a member of the mammalian NAD+‑dependent deacetylase sirtuin family that acts to maintain genomic stability and to repress genes. SIRT6 has recently been reported to be a tumor suppressor that controls cancer metabolism, although this effect of SIRT6 is still in dispute. Moreover, the role of SIRT6 in glioma is largely unknown. In the present study, we found that overexpression of SIRT6 using an adenovirus inhibited glioma cell growth and induced marked cell injury in two glioma cell lines (U87‑MG and T98G). Fluorescent terminal deoxyribonucleotidyl transferase (TdT)‑mediated biotin‑16‑dUTP nick‑end labelling (TUNEL) assay showed that SIRT6 overexpression induced obvious apoptosis in the T98G glioma cells. Immunoblotting and immunofluorescent staining demonstrated that SIRT6 overexpression promoted the mitochondrial-to‑nuclear translocation of apoptosis‑inducing factor (AIF), a potent apoptosis inducer. Moreover, we found that SIRT6 overexpression largely reduced oxidative stress and suppressed the activation of the JAK2/STAT3 signaling pathway in glioma cells. Finally, we showed that SIRT6 mRNA and protein levels in human glioblastoma multiforme tissues were significantly lower than the levels in peritumor tissues. In summary, our data suggest that SIRT6 suppresses glioma cell growth via induction of apoptosis, inhibition of oxidative stress and inhibition of the activation of the JAK2/STAT3 signaling pathway. These results indicate that SIRT6 may be a promising therapeutic target for glioma treatment.