Circulating biomarker panels for targeted therapy in brain tumors

Deciphering immune microenvironment and cell evasion mechanisms in human gliomas

Gliomas are considered one of the most malignant cancers in the body. Despite current therapies, including surgery, chemotherapy, and radiotherapy, these tumors usually recur with more aggressive and resistant phenotypes. Indeed, the survival following these conventional therapies is very poor, which makes immunotherapy the subject of active research at present. The anti-tumor immune response could also be considered a prognostic factor since each stage of cancer development is regulated by immune cells. However, glioma microenvironment contains malignant cells that secrete numerous chemokines, cytokines and growth factors, promoting the infiltration of immunosuppressive cells into the tumor, which limit the functioning of the immune system against glioma cells. Recently, researchers have been able to reverse the immune resistance of cancer cells and thus activate the anti-tumor immune response through different immunotherapy strategies. Here, we review the general concept of glioma's immune microenvironment and report the impact of its distinct components on the anti-tumor immune response. We also discuss the mechanisms of glioma cell evasion from the immune response and pinpoint some potential therapeutic pathways, which could alleviate such resistance.

The impact of heme biosynthesis regulation on glioma aggressiveness: Correlations with diagnostic molecular markers

Background

The prognosis of diffusely infiltrating glioma patients is dismal but varies greatly between individuals. While characterization of gliomas primarily relied on histopathological features, molecular markers increasingly gained importance and play a key role in the recently published 5^th edition of the World Health Organization (WHO) classification. Heme biosynthesis represents a crucial pathway due to its paramount importance in oxygen transport, energy production and drug metabolism. Recently, we described a “heme biosynthesis mRNA expression signature” that correlates with histopathological glioma grade and survival. The aim of the current study was to correlate this heme biosynthesis mRNA expression signature with diagnostic molecular markers and investigate its continued prognostic relevance.

Materials and methods

In this study, patient data were derived from the “The Cancer Genome Atlas” (TCGA) lower-grade glioma and glioblastoma cohorts. We identified diffusely infiltrating gliomas correlating molecular tumor diagnosis according to the most recent WHO classification with heme biosynthesis mRNA expression. The following molecular markers were analyzed: EGFR amplification, TERT promoter mutation, CDKN2A/B homozygous loss, chromosome 7 + /10- aneuploidy, MGMT methylation, IDH mutation, ATRX loss, p53 mutation and 1p19q codeletion. Subsequently, we calculated the heme biosynthesis mRNA expression signature for correlation with distinct molecular glioma markers/molecular subgroups and performed survival analyses.

Results

A total of 649 patients with available data on up-to-date molecular markers and heme biosynthesis mRNA expression were included. According to analysis of individual molecular markers, we found a significantly higher heme biosynthesis mRNA expression signature in gliomas with IDH wildtype (p < 0.0005), without 1p19q codeletion (p < 0.0005), with homozygous CDKN2A/B loss (p < 0.0005) and with EGFR amplification (p = 0.001). Furthermore, we observed that the heme biosynthesis mRNA expression signature increased with molecular subgroup aggressiveness (p < 0.0005), being lowest in WHO grade 2 oligodendrogliomas and highest in WHO grade 4 glioblastomas. Finally, the heme biosynthesis mRNA expression signature was a statistically significant survival predictor after multivariate correction for all molecular markers (p < 0.0005).

Conclusion

Our data demonstrate a significant correlation between heme biosynthesis regulation and diagnostic molecular markers and a prognostic relevance independent of these established markers. Consequently, heme biosynthesis expression is a promising biomarker for glioma aggressiveness and might constitute a potential target for novel therapeutic approaches.

Friends with Benefits: Chemokines, Glioblastoma-Associated Microglia/Macrophages, and Tumor Microenvironment

Glioma is the most common primary intracranial tumor and has the greatest prevalence of all brain tumors. Treatment resistance and tumor recurrence in GBM are mostly explained by considerable alterations within the tumor microenvironment, as well as extraordinary cellular and molecular heterogeneity. Soluble factors, extracellular matrix components, tissue-resident cell types, resident or newly recruited immune cells together make up the GBM microenvironment. Regardless of many immune cells, a profound state of tumor immunosuppression is supported and developed, posing a considerable hurdle to cancer cells' immune-mediated destruction. Several studies have suggested that various GBM subtypes present different modifications in their microenvironment, although the importance of the microenvironment in treatment response has yet to be determined. Understanding the microenvironment and how it changes after therapies is critical because it can influence the remaining invasive GSCs and lead to recurrence. This review article sheds light on the various components of the GBM microenvironment and their roles in tumoral development, as well as immune-related biological processes that support the interconnection/interrelationship between different cell types. Also, we summarize the current understanding of the modulation of soluble factors and highlight the dysregulated inflammatory chemokine/specific receptors cascades/networks and their significance in tumorigenesis, cancer-related inflammation, and metastasis.

Fatty Acids, CD36, Thrombospondin-1, and CD47 in Glioblastoma: Together and/or Separately?

Glioblastoma (GBM) is one of the most aggressive tumors of the central nervous system, characterized by a wide range of inter- and intratumor heterogeneity. Accumulation of fatty acids (FA) metabolites was associated with a low survival rate in high-grade glioma patients. The diversity of brain lipids, especially polyunsaturated fatty acids (PUFAs), is greater than in all other organs and several classes of proteins, such as FA transport proteins (FATPs), and FA translocases are considered principal candidates for PUFAs transport through BBB and delivery of PUFAs to brain cells. Among these, the CD36 FA translocase promotes long-chain FA uptake as well as oxidated lipoproteins. Moreover, CD36 binds and recognizes thrombospondin-1 (TSP-1), an extracellular matrix protein that was shown to play a multifaceted role in cancer as part of the tumor microenvironment. Effects on tumor cells are mediated by TSP-1 through the interaction with CD36 as well as CD47, a member of the immunoglobulin superfamily. TSP-1/CD47 interactions have an important role in the modulation of glioma cell invasion and angiogenesis in GBM. Separately, FA, the two membrane receptors CD36, CD47, and their joint ligand TSP-1 all play a part in GBM pathogenesis. The last research has put in light their interconnection/interrelationship in order to exert a cumulative effect in the modulation of the GBM molecular network.

Putting Proteomics Into Immunotherapy for Glioblastoma

In glioblastoma, the most aggressive brain cancer, a complex microenvironment of heterogeneity and immunosuppression, are considerable hurdles to classify the subtypes and promote treatment progression. Treatments for glioblastoma are similar to standard therapies for many other cancers and do not effectively prolong the survival of patients, due to the unique location and heterogeneous characteristics of glioblastoma. Immunotherapy has shown a promising effect for many other tumors, but its application for glioma still has some challenges. The recent breakthrough of high-throughput liquid chromatography-mass spectrometry (LC-MS/MS) systems has allowed researchers to update their strategy for identifying and quantifying thousands of proteins in a much shorter time with lesser effort. The protein maps can contribute to generating a complete map of regulatory systems to elucidate tumor mechanisms. In particular, newly developed unicellular proteomics could be used to determine the microenvironment and heterogeneity. In addition, a large scale of differentiated proteins provides more ways to precisely classify tumor subtypes and construct a larger library for biomarkers and biotargets, especially for immunotherapy. A series of advanced proteomic studies have been devoted to the different aspects of immunotherapy for glioma, including monoclonal antibodies, oncolytic viruses, dendritic cell (DC) vaccines, and chimeric antigen receptor (CAR) T cells. Thus, the application of proteomics in immunotherapy may accelerate research on the treatment of glioblastoma. In this review, we evaluate the frontline applications of proteomics strategies for immunotherapy in glioblastoma research.

TRIM31 enhances chemoresistance in glioblastoma through activation of the PI3K/Akt signaling pathway

Temozolomide (TMZ) resistance is a complication of treatment of glioma, and new strategies are urgently required to overcome chemoresistance in glioma cells. In the present study, it was demonstrated that tripartite motif-containing 31 (TRIM31) was abnormally upregulated in glioma tissues and cell lines compared with normal samples. Furthermore, the role of TRIM31 was assessed by overexpressing and knocking down its expression. Overexpression of TRIM31 increased cell viability, increased TMZ IC₅₀ values and inhibited apoptosis in A172 and U251 cells; whereas overexpression of TRIM31 decreased the expression of the apoptosis-associated protein p53. Knockdown of TRIM31 increased apoptosis in cells treated with TMZ. Additionally, the mechanisms by which TRIM31 affected glioma cells treated with TMZ were determined. Overexpression of TRIM31 increased phosphorylation of AKT and inhibiting the PI3K/AKT signaling pathway abolished the increase in cell viability and decreased phospho-Akt protein expression in TRIM31 overexpressing A172 cells treated with TMZ. Together, the findings suggest that TRIM31 may be a potentially novel target for glioma chemotherapy.

A four serum-miRNA panel serves as a potential diagnostic biomarker of osteosarcoma

BACKGROUND

Osteosarcoma (OS) is the most common malignant bone tumor in young adults and adolescents with approximately 3 million new cases annually. Due to the lack of sensitive and specific diagnostic biomarkers, although OS patients are curable after surgical resection, many patients suffer from metastasis or recurrence. This study aimed to investigate whether circulating microRNAs (miRNAs) could serve as biomarkers for the diagnosis of OS.

MATERIALS AND METHODS

Healthy individuals and OS patients enrolled in this study came from Nanjing First Hospital. First, candidate miRNAs were selected by integrated analysis of two GEO datasets and a publicly available miRNA dataset. The expression of these miRNAs in tissues and serum samples were subsequently examined through qRT-PCR. The diagnostic utility of these differential miRNAs was examined by using receiver operating characteristic (ROC) curve analysis. Finally, the potential signaling pathways associated with candidate miRNAs were searched through online tools.

RESULTS

Four miRNAs (miR-487a, miR-493-5p, miR-501-3p and miR-502-5p) were selected to further investigate their diagnostic potential for OS. We discovered miR-487a, miR-493-5p, miR-501-3p and miR-502-5p were upregulated in OS tissues and serums. Besides, miR-487a, miR-493-5p, miR-501-3p and miR-502-5p in peripheral blood of OS patients were tumor-derived. The area under the ROC curve (AUC) was 0.83 (95% CI 0.71-0.97) for miR-487a, 0.79 (95% CI 0.66-0.93) for miR-493-5p, 0.82 (95% CI 0.68-0.95) for miR-501-3p, 0.83 (95% CI 0.72-0.95) for miR-502-5p, and 0.89 (95% CI 0.78-1.0) for miRNAs combination.

CONCLUSION

Circulating miR-487a, miR-493-5p, miR-501-3p and miR-502-5p were novel potential diagnostic biomarkers of OS.

Multiplex assay for multiomics advances in personalized-precision medicine

Building the future of precision medicine is the main focus in cancer domain. Clinical trials are moving toward an array of studies that are more adapted to precision medicine. In this domain, there is an enhanced need for biomarkers, monitoring devices, and data-analysis methods. Omics profiling using whole genome, epigenome, transcriptome, proteome, and metabolome can offer detailed information of the human body in an integrative manner. Omes profiles reflect more accurately real-time physiological status. Personalized omics analyses both disease as a whole and the main disease processes, for a better understanding of the individualized health. Through this, multi-omic approaches for health monitoring, preventative medicine, and personalized treatment can be targeted simultaneously and can lead clinicians to have a comprehensive view on the diseasome.

Preoperative Changes in Hematological Markers and Predictors of Glioma Grade and Survival

Background: Preoperative hematological markers that indicate nutritional, coagulation, and inflammation statuses have prognostic value for gliomas. This study aimed to investigate hematological markers with regard to tumor grades, isocitrate dehydrogenase mutations (IDH), age, and sex in patients with gliomas. Methods: From 2008 to 2017, patients with a pathological diagnosis of glioma who underwent surgery were retrospectively enrolled in this study. Information from clinical records, including age, sex, preoperative experiment tests (routine blood tests, biochemistry, and coagulation examinations), pathological results, and IDH status, was collected. A univariable survival analysis was performed. Hematological factors such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte-ratio (PLR), and albumin-to-globulin (AGR) were calculated. The prognostic nutrition index (PNI) was calculated as 10 × serum albumin value (g/dl) + 0.005 × peripheral lymphocyte count (per mm³). Results: Our study included 706 patients. The univariate analysis showed that age, IDH-1, and hematological factors were all significantly associated with overall survival (OS) in patients with gliomas. Our results showed that inflammation markers (NLR, PLR, and fibrinogen) were positively associated with age, whereas AGR was negatively associated with age. The PLR was significantly increased, whereas the AGR and PNI were decreased in women with gliomas, as compared with men. We found that inflammation markers increased and nutrition markers decreased with gliomas grade. However, these hematological markers did not significantly differ with IDH status. NLR was the best single hematological marker for distinguishing glioblastoma (GBM) [0.684 (0.645-0.723)], IDH-wt GBM [0.672 (0.631-0.71)] from other gliomas subtypes. Combinations of age with PNI and age with AGR were the best predictors of GBM [0.750 (0.713-0.786)] and IDH-wt GBM [0.759 (0.719-0.798)], respectively. Conclusion: Preoperative hematological marker levels vary among glioma grades and have high predictive values for GBM.

Overexpression of DJ-1 correlates with aggressive clinicopathological characteristics and poor prognosis in malignant tumors: a meta-analysis

Purpose

A number of studies have investigated the role of DJ-1 in the development and progression of malignant tumors. This meta-analysis aims to systematically estimate the rela-tionship between the expression level of DJ-1 and the malignant biological behaviors of tumors and to assess the clinical significances of DJ-1 in the prognosis and diagnosis of cancer.

Materials and methods

We searched PubMed, Web of Science, China National Knowledge Infrastructure and Wanfang databases from inception to December 1, 2017. Pooled odds ratio (OR) and hazard ratio (HR) with their 95% confidence interval and the diagnostic value of DJ-1 were calculated.

Results

Fourteen eligible studies with a total of 1,947 subjects were enrolled in our meta-analysis. The results showed that DJ-1 was overexpressed in cancer patients compared with noncancer patients (OR = 30.72), and elevated expression of DJ-1 was demonstrated to be closely associated with high tumor-node-metastasis stage (OR = 5.52), poor differentiated degree (OR = 2.46), positive lymph node metastasis (OR = 4.12) and worse overall survival (HR = 2.23). In addition, the combined sensitivity and specificity for DJ-1 to discern malignant tumors were 0.73 and 0.93, respectively. The diagnostic OR was 34.87, and the area under the summary receiver operating characteristic curve was 0.88.

Conclusion

This meta-analysis demonstrated that DJ-1 was an important biomarker in tumor assessment and prognosis prediction.

miR‑141 inhibits glioma vasculogenic mimicry by controlling EphA2 expression

Human glioma is a pernicious tumor from the central nervous system; it has been reported that microRNAs (miRs) may have carcinogenic or tumor suppressor effects on human glioma. The aim of the present study was to assess miR-141 expression and functional role in human primary glioma, as well as in tumor-derived cell lines. The expression of miR-141 in primary human glioma tissues and cell lines was assessed by employing reverse transcription-quantitative polymerase chain reaction. Next, its role in cellular growth, migration, invasion and vasculogenic mimicry (VM) regulation was determined using various in vitro and in vivo assays, and on the identification its target gene(s) using luciferase assays. The results demonstrated that miR-141 expression was downregulated, and Ephrin type-A receptor 2 (EphA2) was upregulated in the primary human gliomas and human glioma-derived cell lines tested. In addition, a negative correlation existed between miR-141 and EphA2 expression levels in glioma grades II, III and IV. Furthermore, exogenous miR-141 expression resulted in decreased proliferation, migration and invasion, as well as in apoptosis and cell cycle arrest in vitro. It was also revealed that exogenous miR-141 expression resulted in in vivo inhibition of tumor growth and inhibition of the development of VM. Finally, the present study successfully confirmed that EphA2 was a direct target of miR-141 in glioma-derived cells using luciferase assays. Based on these results, it was concluded that miR-141 may regulate cell proliferation, migration, invasion and VM formation by controlling EphA2 expression; also, its target EphA2 may be a novel diagnostic/prognostic biomarker and a potential anti-VM therapeutic target.

Intercellular transfer of small RNAs from astrocytes to lung tumor cells induces resistance to chemotherapy

Brain metastases are resistant to chemotherapy and carry a poor prognosis. Studies have shown that tumor cells are surrounded by activated astrocytes, whose cytoprotective properties they exploit for protection from chemotherapy-induced apoptosis. The mechanism of such astrocytic protection is poorly understood. A non-mutational mechanism of resistance to chemotherapy that is receiving increased attention is the regulation of gene translation mediated by small noncoding RNAs (sRNAs), and particularly microRNAs (miRNAs). With the aim of examining the role of astrocytic sRNAs in promoting resistance of human lung tumor PC14 cells to chemotherapy-induced apoptosis, here we used a miRNA microarray to compare sRNA profiles of human lung tumor cells cultured with and without astrocytes. We found that sRNAs are transferred from astrocytes to PC14 cells in a contact-dependent manner. Transfer was rapid, reaching a plateau after only 6 hours in culture. The sRNA transfer was inhibited by the broad-spectrum gap-junction antagonist carbenoxolone, indicating that transfer occurs via gap junctions. Among the transferred sRNAs were several that are implicated in survival pathways. Enforced expression of these sRNAs in PC14 cells increased their resistance to the chemotherapeutic agent paclitaxel. These novel findings might be of clinical relevance for the treatment of patients with brain metastases.

Prostate cancer proteomics: Current trends and future perspectives for biomarker discovery

The clinical and fundamental research in prostate cancer - the most common urological cancer in men - is currently entering the proteomic and genomic era. The focus has switched from one single marker (PSA) to panels of biomarkers (including proteins involved in ribosomal function and heat shock proteins). Novel genetic markers (such as Transmembrane protease serine 2 (TMPRSS2)-ERG fusion gene mRNA) or prostate cancer gene 3 (PCA3) had already entered the clinical practice, raising the question whether subsequent protein changes impact the evolution of the disease and the response to treatment. Proteomic technologies such as MALDI-MS, SELDI-MS, i-TRAQ allow a qualitative/quantitative analysis of the proteome variations, in both serum and tumor tissue. A new trend in prostate cancer research is proteomic analysis of prostasomes (prostate-specific exosomes), for the discovery of new biomarkers. This paper provides an update of novel clinical tests used in research and clinical diagnostic, as well as of potential tissue or fluid biomarkers provided by extensive proteomic research data.

Chronically dysregulated NOTCH1 interactome in the dentate gyrus after traumatic brain injury

Traumatic brain injury (TBI) can result in several dentate gyrus-regulated disabilities. Almost nothing is known about the chronic molecular changes after TBI, and their potential as treatment targets. We hypothesized that chronic transcriptional alterations after TBI are under microRNA (miRNA) control. Expression of miRNAs and their targets in the dentate gyrus was analyzed using microarrays at 3 months after experimental TBI. Of 305 miRNAs present on the miRNA-array, 12 were downregulated (p<0.05). In parallel, 75 of their target genes were upregulated (p<0.05). A bioinformatics analysis of miRNA targets highlighted the dysregulation of the transcription factor NOTCH1 and 39 of its target genes (NOTCH1 interactome). Validation assays confirmed downregulation of miR-139-5p, upregulation of Notch1 and its activated protein, and positive enrichment of NOTCH1 target gene expression. These findings demonstrate that miRNA-based transcriptional regulation can be present at chronic time points after TBI, and highlight the NOTCH1 interactome as one of the mechanisms behind the dentate gyrus pathology-related morbidities.

Glioma Stem Cells and Their Microenvironments: Providers of Challenging Therapeutic Targets

Malignant gliomas are aggressive brain tumors with limited therapeutic options, possibly because of highly tumorigenic subpopulations of glioma stem cells. These cells require specific microenvironments to maintain their “stemness,” described as perivascular and hypoxic niches. Each of those niches induces particular signatures in glioma stem cells (e.g., activation of Notch signaling, secretion of VEGF, bFGF, SDF1 for the vascular niche, activation of HIF2α, and metabolic reprogramming for hypoxic niche). Recently, accumulated knowledge on tumor-associated macrophages, possibly delineating a third niche, has underlined the role of immune cells in glioma progression, via specific chemoattractant factors and cytokines, such as macrophage-colony stimulation factor (M-CSF). The local or myeloid origin of this new component of glioma stem cells niche is yet to be determined. Such niches are being increasingly recognized as key regulators involved in multiple stages of disease progression, therapy resistance, immune-escaping, and distant metastasis, thereby substantially impacting the future development of frontline interventions in clinical oncology. This review focuses on the microenvironment impact on the glioma stem cell biology, emphasizing GSCs cross talk with hypoxic, perivascular, and immune niches and their potential use as targeted therapy.

Proteomic Approaches for Biomarker Panels in Cancer

Proteomic technologies remain the main backbone of biomarkers discovery in cancer. The continuous development of proteomic technologies also enlarges the bioinformatics domain, thus founding the main pillars of cancer therapy. The main source for diagnostic/prognostic/therapy monitoring biomarker panels are molecules that have a dual role, being both indicators of disease development and therapy targets. Proteomic technologies, such as mass-spectrometry approaches and protein array technologies, represent the main technologies that can depict these biomarkers. Herein, we will illustrate some of the most recent strategies for biomarker discovery in cancer, including the development of immune-markers and the use of cancer stem cells as target therapy. The challenges of proteomic biomarker discovery need new forms of cross-disciplinary conglomerates that will result in increased and tailored access to treatments for patients; diagnostic companies would benefit from the enhanced co-development of companion diagnostics and pharmaceutical companies. In the technology optimization in biomarkers, immune assays are the leaders of discovery machinery.