CA10 and CA11 negatively regulate neuronal activity-dependent growth of gliomas

Deciphering the Dialogue between Brain Tumors, Neurons, and Astrocytes

Glioblastoma (GB) and brain metastases (BM) from peripheral tumors account for most cases of tumors in the central nervous system (CNS) while also being the deadliest. From a structural point of view, malignant brain tumors are classically characterized by hypercellularity of glioma and vascular endothelial cells. Given these atypical histologic features, GB and BM have long been considered as "foreign" entities with few to no connections to the brain parenchyma. The identification of intricate connections established between GB cells and the brain parenchyma paired with the ability of peripheral metastatic cells to form functional synapses with neurons challenged the concept of brain tumors disconnected from the CNS. Tumor cell integration to the CNS alters brain functionality in patients and accelerates cancer progression. Next-generation precision medicine should therefore attempt to disconnect brain cancer cells from the brain. This review encompasses recent discoveries on the mechanisms underlying these relationships and discusses the impact of these connections on tumor progression. It also summarizes the therapeutic opportunities of interrupting the dialogue between healthy and neoplastic brains.

Integrating Machine Learning and Mendelian Randomization Determined a Functional Neurotrophin-Related Gene Signature in Patients with Lower-Grade Glioma

Recent researches reported that neurotrophins can promote glioma growth/invasion but the relevant model for predicting patients' survival in Lower-Grade Gliomas (LGGs) lacked. In this study, we adopted univariate Cox analysis, LASSO regression, and multivariate Cox analysis to determine a signature including five neurotrophin-related genes (NTGs), CLIC1, SULF2, TGIF1, TTF2, and WEE1. Two-sample Mendelian Randomization (MR) further explored whether these prognostic-related genes were genetic variants that increase the risk of glioma. A total of 1306 patients have been included in this study, and the results obtained from the training set can be verified by four independent validation sets. The low-risk subgroup had longer overall survival in five datasets, and its AUC values all reached above 0.7. The risk groups divided by the NTGs signature exhibited a distinct difference in targeted therapies from the copy-number variation, somatic mutation, LGG's surrounding microenvironment, and drug response. MR corroborated that TGIF1 was a potential causal target for increasing the risk of glioma. Our study identified a five-NTGs signature that presented an excellent survival prediction and potential biological function, providing new insight for the selection of LGGs therapy.

Genome-wide transcriptome profiling and development of age prediction models in the human brain

Aging-related transcriptome changes in various regions of the healthy human brain have been explored in previous works, however, a study to develop prediction models for age based on the expression levels of specific panels of transcripts is lacking. Moreover, studies that have assessed sexually dimorphic gene activities in the aging brain have reported discrepant results, suggesting that additional studies would be advantageous. The prefrontal cortex (PFC) region was previously shown to have a particularly large number of significant transcriptome alterations during healthy aging in a study that compared different regions in the human brain. We harmonized neuropathologically normal PFC transcriptome datasets obtained from the Gene Expression Omnibus (GEO) repository, ranging in age from 21 to 105 years, and found a large number of differentially regulated transcripts in the old and elderly, compared to young samples overall, and compared female and male-specific expression alterations. We assessed the genes that were associated with age by employing ontology, pathway, and network analyses. Furthermore, we applied various established (least absolute shrinkage and selection operator (Lasso) and Elastic Net (EN)) and recent (eXtreme Gradient Boosting (XGBoost) and Light Gradient Boosting Machine (LightGBM)) machine learning algorithms to develop accurate prediction models for chronological age and validated them. Studies to further validate these models in other large populations and molecular studies to elucidate the potential mechanisms by which the transcripts identified may be related to aging phenotypes would be advantageous.

Neuromodulation for Brain Tumors: Myth or Reality? A Narrative Review

In recent years, research on brain cancers has turned towards the study of the interplay between the tumor and its host, the normal brain. Starting from the establishment of a parallelism between neurogenesis and gliomagenesis, the influence of neuronal activity on the development of brain tumors, particularly gliomas, has been partially unveiled. Notably, direct electrochemical synapses between neurons and glioma cells have been identified, paving the way for new approaches for the cure of brain cancers. Since this novel field of study has been defined "cancer neuroscience", anticancer therapeutic approaches exploiting these discoveries can be referred to as "cancer neuromodulation". In the present review, we provide an up-to-date description of the novel findings and of the therapeutic neuromodulation perspectives in cancer neuroscience. We focus both on more traditional oncologic approaches, aimed at modulating the major pathways involved in cancer neuroscience through drugs or genetic engineering techniques, and on electric stimulation proposals; the latter is at the cutting-edge of neuro-oncology.

An integrated analysis of prognostic mRNA signature in early- and progressive-stage gastric adenocarcinoma

The pathogenesis and vital factors of early and progressive stages of stomach adenocarcinoma (STAD) have not been fully elucidated. In order to discover novel and potential targets to guide effective treatment strategies, a comprehensive bioinformatics study was performed, and the representative results were then validated by quantitative polymerase chain reaction (qPCR) and immunohistochemical (IMC) staining in clinical samples. A total of 4,627, 4,715, and 3,465 differentially expressed genes (DEGs) from overall-, early-, and progressive-stage STAD were identified, respectively. Prognostic models of 5-year OS were established for overall-, early-, and progressive-stage STAD, and ROC curves demonstrated AUC values for each model were 0.73, 0.87, and 0.92, respectively. Function analysis revealed that mRNAs of early-stage STAD were enriched in chemical stimulus-related pathways, whereas remarkable enrichment of mRNAs in progressive-stage STAD mainly lay in immune-related pathways. Both qPCR and IHC data confirmed the up-regulation of IGFBP1 in the early-stage and CHAF1A in progressive-stage STAD compared with their matched normal tissues, indicating that these two representative targets could be used to predict the prognostic status of the patients in these two distinct STAD stages, respectively. In addition, seven mRNAs (F2, GRID2, TF, APOB, KIF18B, INCENP, and GCG) could be potential novel biomarkers for STAD at different stages from this study. These results contributed to identifying STAD patients at high-risk, thus guiding targeted treatment with efficacy in these patients.

Modelling the Human Blood-Brain Barrier in Huntington Disease

While blood–brain barrier (BBB) dysfunction has been described in neurological disorders, including Huntington’s disease (HD), it is not known if endothelial cells themselves are functionally compromised when promoting BBB dysfunction. Furthermore, the underlying mechanisms of BBB dysfunction remain elusive given the limitations with mouse models and post mortem tissue to identify primary deficits. We established models of BBB and undertook a transcriptome and functional analysis of human induced pluripotent stem cell (iPSC)-derived brain-like microvascular endothelial cells (iBMEC) from HD patients or unaffected controls. We demonstrated that HD-iBMECs have abnormalities in barrier properties, as well as in specific BBB functions such as receptor-mediated transcytosis.

Transcriptional Profiling of Hippocampus Identifies Network Alterations in Alzheimer’s Disease

Alzheimer’s disease (AD) is a neurodegenerative disease characterized by rapid brain cell degeneration affecting different areas of the brain. Hippocampus is one of the earliest involved brain regions in the disease. Modern technologies based on high-throughput data have identified transcriptional profiling of several neurological diseases, including AD, for a better comprehension of genetic mechanisms of the disease. In this study, we investigated differentially expressed genes (DEGs) from six Gene Expression Omnibus (GEO) datasets of hippocampus of AD patients. The identified DEGs were submitted to Weighted correlation network analysis (WGCNA) and ClueGo to explore genes with a higher degree centrality and to comprehend their biological role. Subsequently, MCODE was used to identify subnetworks of interconnected DEGs. Our study found 40 down-regulated genes and 36 up-regulated genes as consensus DEGs. Analysis of the co-expression network revealed ACOT7, ATP8A2, CDC42, GAD1, GOT1, INA, NCALD, and WWTR1 to be genes with a higher degree centrality. ClueGO revealed the pathways that were mainly enriched, such as clathrin coat assembly, synaptic vesicle endocytosis, and DNA damage response signal transduction by p53 class mediator. In addition, we found a subnetwork of 12 interconnected genes (AMPH, CA10, CALY, NEFL, SNAP25, SNAP91, SNCB, STMN2, SV2B, SYN2, SYT1, and SYT13). Only CA10 and CALY are targets of known drugs while the others could be potential novel drug targets.

The Prevailing Role of Topoisomerase 2 Beta and its Associated Genes in Neurons

Topoisomerase 2 beta (TOP2β) is an enzyme that alters the topological states of DNA by making a transient double-strand break during the transcription process. The direct interaction of TOP2β with DNA strand results in transcriptional regulation of certain genes and some studies have suggested that a particular set of genes are regulated by TOP2β, which have a prominent role in various stages of neuron from development to degeneration. In this review, we discuss the role of TOP2β in various phases of the neuron's life. Based on the existing reports, we have compiled the list of genes, which are directly regulated by the enzyme, from different studies and performed their functional classification. We discuss the role of these genes in neurogenesis, neuron migration, fate determination, differentiation and maturation, generation of neural circuits, and senescence.

CYB561D2 up-regulation activates STAT3 to induce immunosuppression and aggression in gliomas

BACKGROUND

Fine tuned balance of reactive oxygen species (ROS) is essential for tumor cells and tumor cells use immune checkpoints to evade attack form immunity system. However, it's unclear whether there is any crosstalk between these two pathways. CYB561D2, an antioxidant protein, is part of 5-gene prognosis signature in gliomas and its involvement in gliomas is unknown. Here, we aim to provide a detailed characterization of CYB561D2 in gliomas.

METHODS

CYB561D2 expression was measured in clinical samples of gilomas and normal tissues. The effects of CYB561D2 on immunity related genes and tumor behaviors were investigated in glioma cell lines with various in vitro and in vivo assays.

RESULTS

CYB561D2 expression was enhanced in gliomas compared to control tissues. CYB561D2 up-regulation was associated with high grading of gliomas and short survival in patients. CYB561D2 expression was induced by H2O2 in glioma cell lines. CYB561D2 and its functional product ascorbate activated STAT3 dose-dependently. CYB561D2 over-expression increased PD-L1, CCL2 and TDO2 expression, and induced immunosuppression in co-cultured T cells. In in vitro assays, CYB561D2 knock-down suppressed cell growth, colony formation, migration and promoted apoptosis. In contrast, CYB561D2 over-expression reduced survival rate in intracranial glioma model and this effect could be blocked by dominant negative-STAT3. The CYB561D2 up-regulation and the positive association of CYB561D2 with PD-L1, CCL2 and TDO2 expression were cross-validated in open-access datasets.

CONCLUSIONS

CYB561D2 up-regulation induces immunosuppression and aggression via activating STAT3 in gliomas and CYB561D2 mediates ROS-tumor immunity crosstalk.

CA10 regulates neurexin heparan sulfate addition via a direct binding in the secretory pathway

Neurexins are presynaptic adhesion molecules that shape the molecular composition of synapses. Diversification of neurexins in numerous isoforms is believed to confer synapse-specific properties by engaging with distinct ligands. For example, a subset of neurexin molecules carry a heparan sulfate (HS) glycosaminoglycan that controls ligand binding, but how this post-translational modification is controlled is not known. Here, we observe that CA10, a ligand to neurexin in the secretory pathway, regulates neurexin-HS formation. CA10 is exclusively found on non-HS neurexin and CA10 expressed in neurons is sufficient to suppress HS addition and attenuate ligand binding and synapse formation induced by ligands known to recruit HS. This effect is mediated by a direct interaction in the secretory pathway that blocks the primary step of HS biosynthesis: xylosylation of the serine residue. NMR reveals that CA10 engages residues on either side of the serine that can be HS-modified, suggesting that CA10 sterically blocks xylosyltransferase access in Golgi. These results suggest a mechanism for the regulation of HS on neurexins and exemplify a new mechanism to regulate site-specific glycosylations.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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