Non-Coding RNAs in Glioma

LncRNA LINC00466 Promotes the Progression of Breast Cancer via miR-4731-5p/EPHA2 Pathway

BACKGROUND

Breast Cancer (BC) is a female malignancy with a high mortality rate. Novel diagnostic and prognostic biomarkers are valuable for reducing BC mortality. Our study is designed to undrape the precise role of the LINC00466/miR-4731-5p/EPHA2 axis in BC.

METHODS

The Cancer Genome Atlas (TCGA) sequencing dataset was utilized to compare the levels of LINC00466. The levels of LINC00466, miR-4731-5p, and EPHA2 were tested by qRTPCR. Cell proliferation and cycle were detected by CCK-8 assay and flow cytometer. In vivo role of LINC00466 was tested by Xenograft nude models. Binding sites were predicted by TargetScan and Starbase. The binding relationship was employed by Dual-luciferase reporter gene assay and RNA pull-down assay.

RESULTS

LINC00466 was increased in human breast cancer tissues. LINC00466 was negatively associated with miR-4731-5p and positively correlated with EPHA2 in human breast cancer tissues. Down-regulation of LINC00466 suppressed the proliferation and arrested the cell cycle of breast cancer cells, and inhibited tumor growth in vivo.

CONCLUSION

LINC00466 promoted BC development via mediating the miR-4731-5p/EPHA2 axis, which has the potential value as a promising therapeutic target in BC.

The potential of circulating cell-free RNA in CNS tumor diagnosis and monitoring: A liquid biopsy approach

Early detection of malignancies, through regular cancer screening, has already proven to have potential to increase survival rates. Yet current screening methods rely on invasive, expensive tissue sampling that has hampered widespread use. Liquid biopsy is noninvasive and represents a potential approach to precision oncology, based on molecular profiling of body fluids. Among these, circulating cell-free RNA (cfRNA) has gained attention due to its diverse composition and potential as a sensitive biomarker. This review provides an overview of the processes of cfRNA delivery into the bloodstream and the role of cfRNA detection in the diagnosis of central nervous system (CNS) tumors. Different types of cfRNAs such as microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) have been recognized as potential biomarkers in CNS tumors. These molecules exhibit differential expression patterns in the plasma, cerebrospinalfluid (CSF) and urine of patients with CNS tumors, providing information for diagnosing the disease, predicting outcomes, and assessing treatment effectiveness. Few clinical trials are currently exploring the use of liquid biopsy for detecting and monitoring CNS tumors. Despite obstacles like sample standardization and data analysis, cfRNA shows promise as a tool in the diagnosis and management of CNS tumors, offering opportunities for early detection, personalized therapy, and improved patient outcomes.

The landscape of circRNAs in gliomas temozolomide resistance: Insights into molecular pathways

As the deadliest type of primary brain tumor, gliomas represent a significant worldwide health concern. Circular RNA (circRNA), a unique non-coding RNA molecule, seems to be one of the most alluring target molecules involved in the pathophysiology of many kinds of cancers. CircRNAs have been identified as prospective targets and biomarkers for the diagnosis and treatment of numerous disorders, particularly malignancies. Recent research has established a clinical link between temozolomide (TMZ) resistance and certain circRNA dysregulations in glioma tumors. CircRNAs may play a therapeutic role in controlling or overcoming TMZ resistance in gliomas and may provide guidance for a novel kind of individualized glioma therapy. To address the biological characteristics of circRNAs and their potential to induce resistance to TMZ, this review has highlighted and summarized the possible roles that circRNAs may play in molecular pathways of drug resistance, including the Ras/Raf/ERK PI3K/Akt signaling pathway and metabolic processes in gliomas.

Bibliometric and visualization analysis in the field of epigenetics and glioma (2009-2024)

Introduction

Glioma represents the most prevalent primary malignant tumor in the central nervous system, a deeper understanding of the underlying molecular mechanisms driving glioma is imperative for guiding future treatment strategies. Emerging evidence has implicated a close relationship between glioma development and epigenetic regulation. However, there remains a significant lack of comprehensive summaries in this domain. This study aims to analyze epigenetic publications pertaining to gliomas from 2009 to 2024 using bibliometric methods, consolidate the extant research, and delineate future prospects for investigation in this critical area.

Methods

For the purpose of this study, publications spanning the years 2009 to 2024 were extracted from the esteemed Web of Science Core Collection (WoSCC) database. Utilizing advanced visualization tools such as CiteSpace and VOSviewer, comprehensive data pertaining to various aspects including countries, authors, author co-citations, countries/regions, institutions, journals, cited literature, and keywords were systematically visualized and analyzed.

Results

A thorough analysis was conducted on a comprehensive dataset consisting of 858 publications, which unveiled a discernible trend of steady annual growth in research output within this specific field. The nations of the United States, China, and Germany emerged as the foremost contributors to this research domain. It is noteworthy that von Deimling A and the Helmholtz Association were distinguished as prominent authors and institutions, respectively, in this corpus of literature. A rigorous keyword search and subsequent co-occurrence analysis were executed, ultimately leading to the identification of seven distinct clusters: "epigenetic regulation", "DNA repair", "DNA methylation", "brain tumors", "diffuse midline glioma (DMG)", "U-87 MG" and "epigenomics". Furthermore, an intricate cluster analysis revealed that the primary foci of research within this field were centered around the exploration of glioma pathogenesis and the development of corresponding treatment strategies.

Conclusion

This article underscores the prevailing trends and hotspots in glioma epigenetics, offering invaluable insights that can guide future research endeavors. The investigation of epigenetic mechanisms primarily centers on DNA modification, non-coding RNAs (ncRNAs), and histone modification. Furthermore, the pursuit of overcoming temozolomide (TMZ) resistance and the exploration of diverse emerging therapeutic strategies have emerged as pivotal avenues for future research within the field of glioma epigenetics.

Role of long noncoding RNAs in the regulation of alternative splicing in glioblastoma

Glioblastoma multiforme (GBM) is a highly severe primary brain tumor. Despite extensive research, effective treatments remain elusive. Long noncoding RNAs (lncRNAs) play a significant role in both cancer and normal biology. They influence alternative splicing (AS), which is crucial in cancer. Advances in lncRNA-specific microarrays and next-generation sequencing have enhanced understanding of AS. Abnormal AS contributes to cancer invasion, metastasis, apoptosis, therapeutic resistance, and tumor development, including glioma. lncRNA-mediated AS affects several cellular signaling pathways, promoting or suppressing cancer malignancy. This review discusses the lncRNAs regulating AS in glioblastoma and their mechanisms.

The pathogenesis mechanism and potential clinical value of lncRNA in gliomas

Glioma is the most common malignant tumor in the central nervous system, and its unique pathogenesis often leads to poor treatment outcomes and prognosis. In 2021, the World Health Organization (WHO) divided gliomas into five categories based on their histological characteristics and molecular changes. Non-coding RNA is a type of RNA that does not encode proteins but can exert biological functions at the RNA level, and long non-coding RNA (lncRNA) is a type of non-coding RNA with a length exceeding 200 nt. It is controlled by various transcription factors and plays an indispensable role in the regulatory processes in various cells. Numerous studies have confirmed that the dysregulation of lncRNA is critical in the pathogenesis, progression, and malignancy of gliomas. Therefore, this article reviews the proliferation, apoptosis, invasion, migration, angiogenesis, immune regulation, glycolysis, stemness, and drug resistance changes caused by the dysregulation of lncRNA in gliomas, and summarizes their potential clinical significance in gliomas.

Long non-coding RNA MEG3 knockdown represses airway smooth muscle cells proliferation and migration via sponging miR-143-3p/FGF9 in asthma

BACKGROUND

Asthma is a respiratory disease characterized by airway remodeling. We aimed to find out the role and mechanism of lncRNA MEG3 in asthma.

METHODS

We established a cellular model of asthma by inducing human airway smooth muscle cells (HASMCs) with PDGF-BB, and detected levels of lncRNA MEG3, miR-143-3p and FGF9 in HASMCs through qRT-PCR. The functions of lncRNA MEG3 or miR-143-3p on HASMCs were explored by cell transfection. The binding sites of miR-143-3p and FGF9 were subsequently analyzed with bioinformatics software, and validated with dual-luciferase reporter assay. MTT, 5-Ethynyl-2'-deoxyuridine (EdU) assay, and Transwell were used to detect the effects of lncRNA MEG3 or miR-143-3p on proliferation and migration of HASMCs. QRT-PCR and western blot assay were used to evaluate the level of proliferation-related marker PCNA in HASMCs.

RESULTS

The study found that lncRNA MEG3 negatively correlated with miR-143-3p, and miR-143-3p could directly target with FGF9. Silence of lncRNA MEG3 can suppress migration and proliferation of PDGF-BB-induced HASMCs via increasing miR-143-3p. Further mechanistic studies revealed that miR-143-3p negatively regulated FGF9 expression in HASMCs. MiR-143-3p could inhibit PDGF-BB-induced HASMCs migration and proliferation through downregulating FGF9.

CONCLUSION

LncRNA MEG3 silencing could inhibit the migration and proliferation of HASMCs through regulating miR-143-3p/FGF9 signaling axis. These results imply that lncRNA MEG3 plays a protective role against asthma.

circPDK1 competitively binds miR-4731-5p to mediate GIGYF1 expression and increase paclitaxel sensitivity in non-small cell lung cancer

OBJECTIVE

To investigate the action of circPDK1 in paclitaxel (PTX) resistance in non-small cell lung cancer (NSCLC).

METHODS

circPDK1, miR-4731-5p, and GIGYF1 levels were determined by RT-qPCR and Western blot. Cell proliferation was detected by CCK-8 and colony formation assay, apoptosis by flow cytometry, invasion by Transwell assay. The targeting relationship between miR-4731-5p and circPDK1 or GIGYF1 was confirmed by dual luciferase reporter gene and RIP assay. A xenograft tumor model was established to determine the role of circPDK1 in PTX resistance.

RESULTS

circPDK1 was overexpressed in PTX-resistant NSCLC, and depleting circPDK1 hampered proliferation and invasion of PTX-resistant cells, activated apoptosis, and improved PTX sensitivity. circPDK1 bound to miR-4731-5p, and increasing miR-4731-5p expression salvaged the effect of circPDK1 depletion on PTX resistance. miR-4731-5p directly targeted GIGYF1, and upregulating GIGYF1 offset the promoting effect of circPDK1 knockdown on PTX sensitivity. NSCLC tumor growth was inhibited and PTX sensitivity improved when circPDK1 was suppressed.

CONCLUSION

Depleting circPDK1 promotes PTX sensitivity of NSCLC cells via miR-4731-5p/GIGYF1 axis, thereby inhibiting NSCLC pregnancy.

LncRNA NUTM2A-AS1 silencing inhibits glioma via miR-376a-3p/YAP1 axis

The lncRNA NUTM2A-AS1 has been shown to be dysregulated in gastric cancer, while the roles in glioma is unclear. The aim of this study was to investigate the roles and potential mechanisms of lncRNA NUTM2A-AS1 in the proliferation and apoptosis of glioma cells. The StarBase software and dual luciferase reporter assay were used to identify the relationship between lncRNA NUTM2A-AS1 and miR-376a-3p, and miR-376a-3p and YAP1. The expression of lncRNA NUTM2A-AS1, miR-376a-3p, and YAP1 in human glioma cell lines was detected by qRT-PCR. MTT and flow cytometry were used to detect the effects of lncRNA NUTM2A-AS1 or miR-376a-3p on the proliferation and apoptosis of U251 and A172 cells, respectively. In addition, changes of Bax and Bcl-2 expression in glioma cells were further verified by western blotting and qRT-PCR. The results showed that the expression of lncRNA NUTM2A-AS1 was elevated in glioma cell lines, while miR-376a-3p was decreased. LncRNA NUTM2A-AS1 was negatively correlated with miR-376a-3p. Silencing of lncRNA NUTM2A-AS1 enhanced the levels of miR-376a-3p, leading to reduced cell proliferation and increased apoptosis in glioma cells. YAP1 was a direct target of miR-376a-3p, and it was negatively regulated by miR-376a-3p in U251 and A172 cells. Further mechanistic studies suggested that miR-376a-3p reduced glioma cell proliferation and increased apoptosis by inhibiting YAP1 expression. In addition, lncRNA NUTM2A-AS1 positively regulated of YAP1 expression in glioma cells. In conclusion, silencing of lncRNA NUTM2A-AS1 inhibited proliferation and induced apoptosis in human glioma cells via the miR-376a-3p/YAP1 axis.

Etomidate inhibits tumor growth of glioblastoma by regulating M1 macrophage polarization

Glioblastoma (GBM) is a common primary central nervous system tumor. Although the multimodal integrated treatment for GBM has made great progress in recent years, the overall survival time of GBM is still short. Thus, novel treatments for GBM are worth further investigation and exploration. This study aimed to investigate the effects of etomidate on GBM tumor growth and the underlying mechanism. A xenograft tumor model was established and treated with etomidate to assess tumor growth. Immunohistochemistry (IHC) assay evaluated the positive rate of Ki67 cells in tumor tissues. Cell counting kit (CCK)-8 and EdU assays accessed the cell viability and proliferation. Immunofluorescence (IF) staining detected the distribution of macrophage markers in tumor tissues. The percentages of M1- and M2-like macrophages in tumor-associated macrophages (TAMs) and co-culture system (macrophages and GBM cells) were detected using flow cytometry. Macrophage polarization-related genes were measured using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Etomidate treatment inhibited the tumor growth, and increased the CD86+ cells but decreased the CD206+ cells in TAMs. The gene expression of M1 markers was increased in TAMs of etomidate-treated mice, whereas that of M2 markers was decreased. Moreover, etomidate treatment increased the number of CD86+ M1-like macrophages co-cultured with tumor cells but decreased that of CD206+ M2-like macrophages, with the upregulation of M1 markers and downregulation of M2 markers. Etomidate inhibited GBM tumor growth by promoting M1 macrophage polarization, suggesting a new insight into the clinical treatment of GBM.

The Interplay between Glioblastoma Cells and Tumor Microenvironment: New Perspectives for Early Diagnosis and Targeted Cancer Therapy

Glioblastoma multiforme (GBM) stands out as the most tremendous brain tumor, constituting 60% of primary brain cancers, accompanied by dismal survival rates. Despite advancements in research, therapeutic options remain limited to chemotherapy and surgery. GBM molecular heterogeneity, the intricate interaction with the tumor microenvironment (TME), and non-selective treatments contribute to the neoplastic relapse. Diagnostic challenges arise from GBM advanced-stage detection, necessitating the exploration of novel biomarkers for early diagnosis. Using data from the literature and a bioinformatic tool, the current manuscript delineates the molecular interplay between human GBM, astrocytes, and myeloid cells, underscoring selected protein pathways belonging to astroglia and myeloid lineage, which can be considered for targeted therapies. Moreover, the pivotal role of extracellular vesicles (EVs) in orchestrating a favorable microenvironment for cancer progression is highlighted, suggesting their utility in identifying biomarkers for GBM early diagnosis.

Expression of lncRNAs in glioma: A lighthouse for patients with glioma

Glioma is the most common malignant tumour in the central nervous system, accounting for approximately 30 % of the primary tumours of this system. The World Health Organization grades for glioma include: Grade I (pilocytic astrocytoma), Grade II (astrocytoma, oligodastoma, etc.), Grade III (anaplastic astrocytoma, anaplastic oligodastoma, etc.) and Grade IV (glioblastoma). With grade increases, the proliferation, invasion and other malignant biological properties of the glioma are enhanced, and the treatment results are less satisfactory. The overall survival of patients with glioblastoma is less than 15 months. Recent research has focused on the roles of long non-coding RNAs, previously regarded as "transcriptional noise", in diseases, leading to a new understanding of these roles. Therefore, we conducted this review to explore the progress of research regarding the expression and mechanism of long non-coding RNAs in glioma.

Non-coding RNAs as Key Regulators of the Notch Signaling Pathway in Glioblastoma: Diagnostic, Prognostic, and Therapeutic Targets

Glioblastoma multiforme (GBM) is a highly invasive brain malignancy originating from astrocytes, accounting for approximately 30% of central nervous system malignancies. Despite advancements in therapeutic strategies including surgery, chemotherapy, and radiopharmaceutical drugs, the prognosis for GBM patients remains dismal. The aggressive nature of GBM necessitates the identification of molecular targets and the exploration of effective treatments to inhibit its proliferation. The Notch signaling pathway, which plays a critical role in cellular homeostasis, becomes deregulated in GBM, leading to increased expression of pathway target genes such as MYC, Hes1, and Hey1, thereby promoting cellular proliferation and differentiation. Recent research has highlighted the regulatory role of non-coding RNAs (ncRNAs) in modulating Notch signaling by targeting critical mRNA expression at the post-transcriptional or transcriptional levels. Specifically, various types of ncRNAs, including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), have been shown to control multiple target genes and significantly contribute to the carcinogenesis of GBM. Furthermore, these ncRNAs hold promise as prognostic and predictive markers for GBM. This review aims to summarize the latest studies investigating the regulatory effects of ncRNAs on the Notch signaling pathway in GBM.

Y-box protein-1 modulates circSPECC1 to promote glioma tumorigenesis via miR-615-5p/HIP1/AKT axis

Y-box binding protein-1 (YB-1) is upregulated in glioma and plays an important role in its occurrence and drug resistance. However, the involved regulatory processes and downstream pathways are still unclear. Since various circular RNAs (circRNAs) and microRNAs (miRNAs) also play roles in the pathogenesis of glioma, we hypothesize that YB-1 may exert its function through a circRNA-miRNA-protein interaction network. In this study, we use the RNA binding protein immunoprecipitation assay and quantitative reverse transcription polymerase chain reaction to determine the circRNAs involved in the regulation of YB-1 and further elucidate their biological functions. The level of circSPECC1 (hsa_circ_0000745) modulated by YB-1 is significantly upregulated in the U251 and U87 glioma cell lines. Downregulation of circSPECC1 markedly inhibits the proliferation and invasiveness of U251 and U87 cells by inducing apoptosis. Bioinformatics analysis reveals that miR-615-5p could interact with circSPECC1 and huntingtin-interacting protein-1 (HIP-1). Then we determine the interactions between miR-615-5p, circSPECC1, and HIP1 using dual luciferase reporter system and pull-down assays. Mechanistic analysis indicates that the downregulation of circSPECC1 results in a decreased HIP1 expression. This study demonstrates that circSPECC1 modulated by YB-1 is increased in glioma cell lines. In addition, circSPECC1 promotes glioma growth through the upregulation of HIP1 by sponging miR-615-5p and targeting the HIP1/AKT pathway. This indicates that YB-1 and circSPECC1 may both be promising targets for glioma treatment.

The role and clinical relevance of long non-coding RNAs in glioma

Glioma represents a complex and heterogeneous disease, posing significant challenges to both clinicians and researchers. Despite notable advancements in glioma treatment, the overall survival rate for most glioma patients remains dishearteningly low. Hence, there is an urgent necessity to discover novel biomarkers and therapeutic targets specifically tailored for glioma. In recent years, long non-coding RNAs (lncRNAs) have emerged as pivotal regulators of gene expression and have garnered attention for their involvement in the development and progression of various cancers, including glioma. The dysregulation of lncRNAs plays a critical role in glioma pathogenesis and influences clinical outcomes. Consequently, there is growing interest in exploring the potential of lncRNAs as diagnostic and prognostic biomarkers, as well as therapeutic targets. By understanding the functions and dysregulation of lncRNAs in glioma, researchers aim to unlock new avenues for the development of innovative treatment strategies catered to glioma patients. The identification and thorough characterization of lncRNAs hold the promise of novel therapeutic approaches that could potentially improve patient outcomes and enhance the management of glioma, ultimately striving for better prospects and enhanced quality of life for those affected by this challenging disease. The primary objective of this paper is to comprehensively review the current state of knowledge regarding lncRNA biology and their intricate roles in glioma. It also delves into the potential of lncRNAs as valuable diagnostic and prognostic indicators and explores their feasibility as promising targets for therapeutic interventions.

Transcriptome driven discovery of novel candidate genes for human neurological disorders in the telomer-to-telomer genome assembly era

BACKGROUND

With the first complete draft of a human genome, the Telomere-to-Telomere Consortium unlocked previously concealed genomic regions for genetic analyses. These regions harbour nearly 2000 potential novel genes with unknown function. In order to uncover candidate genes associated with human neurological pathologies, a comparative transcriptome study using the T2T-CHM13 and the GRCh38 genome assemblies was conducted on previously published datasets for eight distinct human neurological disorders.

RESULTS

The analysis of differential expression in RNA sequencing data led to the identification of 336 novel candidate genes linked to human neurological disorders. Additionally, it was revealed that, on average, 3.6% of the differentially expressed genes detected with the GRCh38 assembly may represent potential false positives. Among the noteworthy findings, two novel genes were discovered, one encoding a pore-structured protein and the other a highly ordered β-strand-rich protein. These genes exhibited upregulation in multiple epilepsy datasets and hold promise as candidate genes potentially modulating the progression of the disease. Furthermore, an analysis of RNA derived from white matter lesions in multiple sclerosis patients indicated significant upregulation of 26 rRNA encoding genes. Additionally, putative pathology related genes were identified for Alzheimer's disease, amyotrophic lateral sclerosis, glioblastoma, glioma, and conditions resulting from the m.3242 A > G mtDNA mutation.

CONCLUSION

The results presented here underline the potential of the T2T-CHM13 assembly in facilitating the discovery of candidate genes from transcriptome data in the context of human disorders. Moreover, the results demonstrate the value of remapping sequencing data to a superior genome assembly. Numerous potential pathology related genes, either as causative factors or related elements, have been unveiled, warranting further experimental validation.

microRNAs (miRNAs) in Glioblastoma Multiforme (GBM)-Recent Literature Review

Glioblastoma multiforme (GBM) is the most common, malignant, poorly promising primary brain tumor. GBM is characterized by an infiltrating growth nature, abundant vascularization, and a rapid and aggressive clinical course. For many years, the standard treatment of gliomas has invariably been surgical treatment supported by radio- and chemotherapy. Due to the location and significant resistance of gliomas to conventional therapies, the prognosis of glioblastoma patients is very poor and the cure rate is low. The search for new therapy targets and effective therapeutic tools for cancer treatment is a current challenge for medicine and science. microRNAs (miRNAs) play a key role in many cellular processes, such as growth, differentiation, cell division, apoptosis, and cell signaling. Their discovery was a breakthrough in the diagnosis and prognosis of many diseases. Understanding the structure of miRNAs may contribute to the understanding of the mechanisms of cellular regulation dependent on miRNA and the pathogenesis of diseases underlying these short non-coding RNAs, including glial brain tumors. This paper provides a detailed review of the latest reports on the relationship between changes in the expression of individual microRNAs and the formation and development of gliomas. The use of miRNAs in the treatment of this cancer is also discussed.

Circular RNAs-New Kids on the Block in Cancer Pathophysiology and Management

The ever-increasing number of cancer cases and persistently high mortality underlines the urgent need to acquire new perspectives for developing innovative therapeutic approaches. As the research on protein-coding genes brought significant yet only incremental progress in the development of anticancer therapy, much attention is now devoted to understanding the role of non-coding RNAs (ncRNAs) in various types of cancer. Recent years have brought about the awareness that ncRNAs recognized previously as "dark matter" are, in fact, key players in shaping cancer development. Moreover, breakthrough discoveries concerning the role of a new group of ncRNAs, circular RNAs, have evidenced their high importance in many diseases, including malignancies. Therefore, in the following review, we focus on the role of circular RNAs in cancer, particularly in cancer stem-like cells, summarize their mechanisms of action, and provide an overview of the state-of-the-art toolkits to study them.

Non-Association of Driver Alterations in PTEN with Differential Gene Expression and Gene Methylation in IDH1 Wildtype Glioblastomas

During oncogenesis, alterations in driver genes called driver alterations (DAs) modulate the transcriptome, methylome and proteome through oncogenic signaling pathways. These modulatory effects of any DA may be analyzed by examining differentially expressed mRNAs (DEMs), differentially methylated genes (DMGs) and differentially expressed proteins (DEPs) between tumor samples with and without that DA. We aimed to analyze these modulations with 12 common driver genes in Isocitrate Dehydrogenase 1 wildtype glioblastomas (IDH1-W-GBs). Using Cbioportal, groups of tumor samples with and without DAs in these 12 genes were generated from the IDH1-W-GBs available from "The Cancer Genomics Atlas Firehose Legacy Study Group" (TCGA-FL-SG) on Glioblastomas (GBs). For all 12 genes, samples with and without DAs were compared for DEMs, DMGs and DEPs. We found that DAs in PTEN were unassociated with any DEM or DMG in contrast to DAs in all other drivers, which were associated with several DEMs and DMGs. This contrasting PTEN-related property of being unassociated with differential gene expression or methylation in IDH1-W-GBs was unaffected by concurrent DAs in other common drivers or by the types of DAs affecting PTEN. From the lists of DEMs and DMGs associated with some common drivers other than PTEN, enriched gene ontology terms and insights into the co-regulatory effects of these drivers on the transcriptome were obtained. The findings from this study can improve our understanding of the molecular mechanisms underlying gliomagenesis with potential therapeutic benefits.

Iron Oxide Nanoparticles Decorated with Functional Peptides for a Targeted siRNA Delivery to Glioma Cells

Glioma is a deadly form of brain cancer, and the difficulty of treating glioma is exacerbated by the chemotherapeutic resistance developed in the tumor cells over the time of treatment. siRNA can be used to silence the gene responsible for the increased resistance, and sensitize the glioma cells to drugs. Here, iron oxide nanoparticles functionalized with peptides (NP-CTX-R10) were used to deliver siRNA to silence O6-methylguanine-DNA methyltransferase (MGMT) to sensitize tumor cells to alkylating drug, Temozolomide (TMZ). The NP-CTX-R10 could complex with siRNA through electrostatic interactions and was able to deliver the siRNA to different glioma cells. The targeting ligand chlorotoxin and cell penetrating peptide polyarginine (R10) enhanced the transfection capability of siRNA to a level comparable to commercially available Lipofectamine. The NP-siRNA was able to achieve up to 90% gene silencing. Glioma cells transfected with NP-siRNA targeting MGMT showed significantly elevated sensitivity to TMZ treatment. This nanoparticle formulation demonstrates the ability to protect siRNA from degradation and to efficiently deliver the siRNA to induce therapeutic gene knockdown.

Particulate Matters Affecting lncRNA Dysregulation and Glioblastoma Invasiveness: In Silico Applications and Current Insights

With a reported rise in global air pollution, more than 50% of the population remains exposed to toxic air pollutants in the form of particulate matters (PMs). PMs, from various sources and of varying sizes, have a significant impact on health as long-time exposure to them has seen a correlation with various health hazards and have also been determined to be carcinogenic. In addition to disrupting known cellular pathways, PMs have also been associated with lncRNA dysregulation-a factor that increases predisposition towards the onset or progression of cancer. lncRNA dysregulation is further seen to mediate glioblastoma multiforme (GBM) progression. The vast array of information regarding cancer types including GBM and its various precursors can easily be obtained via innovative in silico approaches in the form of databases such as GEO and TCGA; however, a need to obtain selective and specific information correlating anthropogenic factors and disease progression-in the case of GBM-can serve as a critical tool to filter down and target specific PMs and lncRNAs responsible for regulating key cancer hallmarks in glioblastoma. The current review article proposes an in silico approach in the form of a database that reviews current updates on correlation of PMs with lncRNA dysregulation leading to GBM progression.

Noncoding RNA-mediated regulation of pyroptotic cell death in cancer

Pyroptosis is a newly discovered form of programmed cell death, which is manifested by DNA fragmentation, cell swelling, cell membrane rupture and leakage of cell contents. Previous studies have demonstrated that pyroptosis is tightly associated with the initiation and development of various cancers, whereas the molecular mechanisms underlying pyroptosis remain obscure. Noncoding RNAs (ncRNAs) are a type of heterogeneous transcripts that are broadly expressed in mammalian cells. Owing to their potency of regulating gene expression, ncRNAs play essential roles in physiological and pathological processes. NcRNAs are increasingly acknowledged as important regulators of the pyroptosis process. Importantly, the crosstalk between ncRNAs and pyroptosis affects various hallmarks of cancer, including cell growth, survival, metastasis and therapeutic resistance. The study of the involvement of pyroptosis-associated ncRNAs in cancer pathobiology has become a hot area in recent years, while there are limited reviews on this topic. Herein, we provide an overview of the complicated roles of ncRNAs, mainly including microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), in modulating pyroptosis, with a focus on the underlying mechanisms of the ncRNA-pyroptosis axis in cancer pathogenesis. Finally, we discuss the potential applications and challenges of exploiting pyroptosis-regulating ncRNAs as molecular biomarkers and therapeutic targets in cancer.

A novel inflammation-related lncRNAs prognostic signature identifies LINC00346 in promoting proliferation, migration, and immune infiltration of glioma

In this study, a total of 13 inflammation-related lncRNAs with a high prognostic value were identified with univariate, multivariate Cox regression analysis, and LASSO analysis. LINC00346, which is one of the 13 lncRNAs identified, was positively associated with type 2 macrophage activation and the malignant degree of glioma. Fluorescence in situ hybridization (FISH) and immunohistochemical staining showed that LINC00346 was highly expressed in high-grade glioma, while type 2 macrophages key transcription factor STAT3 and surface marker CD204 were also highly expressed simultaneously. LINC00346 high-expression gliomas were more sensitive to the anti–PD-1 and anti-CTLA-4 therapy. LINC00346 was also associated with tumor proliferation and tumor migration validated by EdU, cell colony, formation CCK8, and transwell assays. These findings reveal novel biomarkers for predicting glioma prognosis and outline relationships between lncRNAs inflammation, and glioma, as well as possible immune checkpoint targets for glioma.

Regulation of temozolomide resistance via lncRNAs: Clinical and biological properties of lncRNAs in gliomas (Review)

Gliomas are a primary types of intracranial malignancies and are characterized by a poor prognosis due to aggressive recurrence profiles. Temozolomide (TMZ) is an auxiliary alkylating agent that is extensively used in conjunction with surgical resection and forms the mainstay of clinical treatment strategies for gliomas. However, the frequent occurrence of TMZ resistance in clinical practice limits its therapeutic efficacy. Accumulating evidence has demonstrated that long non‑coding RNAs (lncRNAs) can play key and varied roles in glioma progression. lncRNAs have been reported to inhibit glioma progression by targeting various signaling pathways. In addition, the differential expression of lncRNAs has also been found to mediate the resistance of glioma to several chemotherapeutic agents, particularly to TMZ. The present review article therefore summarizes the findings of previous studies in an aim to report the significance and function of lncRNAs in regulating the chemoresistance of gliomas. The present review may provide further insight into the clinical treatment of gliomas.

The Role of Non-Coding RNAs in Glioma

For decades, research in cancer biology has been focused on the protein-coding fraction of the human genome. However, with the discovery of non-coding RNAs (ncRNAs), it has become known that these entities not only function in numerous fundamental life processes such as growth, differentiation, and development, but also play critical roles in a wide spectrum of human diseases, including cancer. Dysregulated ncRNA expression is found to affect cancer initiation, progression, and therapy resistance, through transcriptional, post-transcriptional, or epigenetic processes in the cell. In this review, we focus on the recent development and advances in ncRNA biology that are pertinent to their role in glioma tumorigenesis and therapy response. Gliomas are common, and are the most aggressive type of primary tumors, which account for ~30% of central nervous system (CNS) tumors. Of these, glioblastoma (GBM), which are grade IV tumors, are the most lethal brain tumors. Only 5% of GBM patients survive beyond five years upon diagnosis. Hence, a deeper understanding of the cellular non-coding transcriptome might help identify biomarkers and therapeutic agents for a better treatment of glioma. Here, we delve into the functional roles of microRNA (miRNA), long non-coding RNA (lncRNA), and circular RNA (circRNA) in glioma tumorigenesis, discuss the function of their extracellular counterparts, and highlight their potential as biomarkers and therapeutic agents in glioma.

lncRNA MEG3 Inhibits the Proliferation and Growth of Glioma Cells by Downregulating Bcl-xL in the PI3K/Akt/NF-κB Signal Pathway

This study was conducted to investigate the impact and mechanisms of lncRNA MEG3 on glioma cells. lncRNA MEG3 was lowly expressed in glioma cells as compared to noncancer cells. Overexpression of MEG3 significantly downregulated the expression of Bcl-xL, slightly upregulated the expression of NF-κB p65 and IκBα, and reduced the proliferation of glioma cells with increased apoptosis and the migration and invasion ability. Subsequently, glioma cells overexpressing MEG3 had less tumorgenicity in xenograft mouse models. It is likely that MEG3 induces apoptosis in glioma cells via downregulating the Bcl-xL gene in the PI3K/Akt/NF-κB signal pathway to reduce the development of glioma.

Computational epigenetic landscape analysis reveals association of CACNA1G-AS1, F11-AS1, NNT-AS1, and MSC-AS1 lncRNAs in prostate cancer progression through aberrant methylation

Aberrant expression of long non-coding RNAs (lncRNAs), caused by alterations in DNA methylation, is a driving factor in several cancers. Interplay between lncRNAs’ aberrant methylation and expression in prostate cancer (PC) progression still remains largely elusive. Therefore, this study characterized the genome-wide epigenetic landscape and expression profiles of lncRNAs and their clinical impact by integrating multi-omics data implementing bioinformatics approaches. We identified 62 differentially methylated CpG-sites (DMCs) and 199 differentially expressed lncRNAs (DElncRNAs), where 32 DElncRNAs contain 32 corresponding DMCs within promoter regions. Significant negative correlation was observed between 8 DElncRNAs-DMCs pairs. 3 (cg23614229, cg23957912, and cg11052780) DMCs and 4 (CACNA1G-AS1, F11-AS1, NNT-AS1, and MSC-AS1) DElncRNAs were identified as high-risk factors for poor prognosis of PC patients. Overexpression of hypo-methylated CACNA1G-AS1, F11-AS1, and NNT-AS1 and down-regulation of hyper-methylated MSC-AS1 significantly lower the survival of PC patients and could be a potential prognostic and therapeutic biomarker. These DElncRNAs were found to be associated with several molecular functions whose deregulation can lead to cancer. Involvement of these epigenetically deregulated DElncRNAs in cancer-related biological processes was also noticed. These findings provide new insights into the understanding of lncRNA regulation by aberrant DNA methylation which will help to clarify the epigenetic mechanisms underlying PC.

LncRNA HOTAIR sponges miR-301a-3p to promote glioblastoma proliferation and invasion through upregulating FOSL1

Glioblastoma, one of the most fatal brain tumors, is associated with a dismal prognosis and an extremely short overall survival. We previously reported that the overexpressed transient receptor potential channel TRPM7 is an essential glioblastoma regulator. Accumulating evidence suggests that long noncoding RNAs (lncRNAs) play an important role in glioma's initiation and progression. However, the function of lncRNA, HOX transcript antisense intergenic RNA (HOTAIR) mediated by TRPM7 in glioma remains unclear. In this study, HOTAIR expression was found to be positively regulated by TRPM7, significantly upregulated in glioma tissues, and is a poor prognosis factor for glioma patients. Moreover, reduced HOTAIR expression impeded the proliferation and invasion of glioma cells. Mechanistically, HOTAIR directly interacted with miR-301a-3p, and downregulation of miR-301a-3p efficiently reversed FOSL1 suppression induced by siRNA HOTAIR, which implied that HOTAIR positively regulated FOSL1 level through sponging miR-301a-3p and played an oncogenic role in glioma progression. In contrast to HOTAIR's role, miR-301a-3p alone served as a tumor suppressor to decrease glioma cell viability and migration/invasion. In agreement with HOTAIR's role, FOSL1 functioned as a tumorigenic gene in glioma pathogenesis, which was highly expressed in glioma tissues, and was shown to be an unfavorable prognostic factor for glioma patients. Mechanically, FOSL1 inhibition by siRNA FOSL1 efficiently rescued the oncogenic-like phenotypes caused by the miR-301a-3p inhibitor in glioma pathogenesis. SIGNIFICANCE: Our study elucidated the role of TRPM7-mediated HOTAIR as a miRNA sponge to target downstream FOSL1 oncogene and therefore consequently contribute to gliomagenesis, which shed new light on TRPM7/lncRNA-directed diagnostic and therapeutic approach in glioma.

Up-regulation of LINC00665 contributes to the progression of glioma and correlates with its MRI characteristics

BACKGROUND

LncRNA LINC00665 partakes in controlling the malignant phenotype of cancer cells, but its role in glioma and the related regulatory mechanism remain uncertain.

METHODS

RT-PCR was exploited to examine LINC00665 expression. The relationships among the LINC00665 expression, the clinicopathologic values and magnetic resonance imaging (MRI) characteristics of glioma were analyzed. The multiplication, movement, and aggressiveness of glioma cell lines were evaluated by CCK-8, EdU, and Transwell experiments after constructing LINC00665 overexpression and LINC00665 knockdown cell models. A dual-luciferase reporter gene experiment and RIP experiment were executed to validate the interactions between LINC00665 and miR-129-5p, and between miR-129-5p and HMGB1. Western blot and RT-PCR were conducted to find the impact of LINC00665 and miR-129-5p on HMGB1 expression. Nude mouse model was also constructed to examine the impact of LINC00665 on multiplication and aggressiveness of glioma cells in vivo.

RESULTS

LINC00665 expression was markedly increased in glioma. High LINC00665 expression in glioma was closely linked to larger tumor diameter, higher pathologic grade, heterogeneous MRI signal of the tumor, increased peritumoral edema, and stronger MRI enhancement characteristics. LINC00665 overexpression facilitated the malignant behavior of glioma cells, while LINC00665 knockdown played the reverse role. Mechanistically, LINC00665 could decoy miR-129-5p, and indirectly increased HMGB1 expression.

CONCLUSION

LINC00665 functions as an oncogenic lncRNA in glioma, to accelerate glioma progression by modulating miR-129-5p and increasing HMGB1 expression.

Circulating miRNAs as Diagnostic and Prognostic Biomarkers in High-Grade Gliomas

Objectives

miR-181a/b and miR-410 downregulation and miR-155 upregulation has been shown to play important roles in the oncogenesis and progression of gliomas including high-grade gliomas. However, the potential role of plasma miR-181a/b, miR-410 and miR-155 in the diagnosis and prognosis of high-grade gliomas remains poorly known.

Methods

We retrieved published articles from the PubMed, the Cochrane Central Register of Controlled Trials, and Web of Science database and obtained different sets of data on microRNAs (miRNAs) expression profiling in glioma and highlighted the most frequently dysregulated miRNAs and their gene-targets (PDCD4, WNT5A, MET, and EGFR) in high-grade gliomas. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was carried out to measure the pre- and postoperative plasma levels of miR-181a/b, miR-410 and miR-155 in 114 Grade 3-4 glioma patients, 77 Grade 1-2 glioma patients and 85 healthy volunteers as control group. The diagnostic and prognostic value of circulating miR-181a/b, miR-410 and miR-155 as biomarker was estimated by the Receiver Operating Characteristic (ROC) curve and the area under the curve (AUC) and Kaplan–Meier analysis.

Results

We found a plasma miRNA signature including three downexpressed miRNAs and one overexpressed (miR-181a, miR-181b and miR-410; miR-155) in high-grade glioma patients in comparison with low-grade glioma patients control group. The ROC curve AUC of these four circulating miRNAs were ≥ 0.75 for high-grade glioma patients in before and after surgery. Higher circulating miR-155 and lower miR-181a/b and miR-410 expression is associated with clinical data, clinic pathological variables, worse overall survival (OS) of patients and negative correlated with potential gene-targets expression. Moreover, Kaplan–Meier analysis showed that miR-181a/b, miR-410 and miR-155 were independent predictors of OS in high-grade glioma patients.

Conclusions

Our data, for the first time, demonstrated that circulating miR-181a/b, miR-410 and miR-155 could be a useful diagnostic and prognostic non-invasive biomarkers in high-grade gliomas.

Effects of microRNAs and long non-coding RNAs on chemotherapy response in glioma

Glioma is the most prevalent invasive primary tumor of the central nervous system. Glioma cells can spread and infiltrate into normal surrounding brain tissues. Despite the standard use of chemotherapy and radiotherapy after surgery in glioma patients, treatment resistance is still a problem, as the underlying mechanisms are still not fully understood. Non-coding RNAs are widely involved in tumor progression and treatment resistance mechanisms. In the present review, we discuss the pathways by which microRNAs and long non-coding RNAs can affect resistance to chemotherapy and radiotherapy, as well as offer potential therapeutic options for future glioma treatment.

Clinical Significance and Immune Landscape of a Pyroptosis-Derived LncRNA Signature for Glioblastoma

Introduction: Pyroptosis was recently implicated in the initiation and progression of tumors, including glioblastoma (GBM). This study aimed to explore the clinical significance of pyroptosis-related lncRNAs (PRLs) in GBM.

Methods: Three independent cohorts were retrieved from the TCGA and CGGA databases. The consensus clustering and weighted gene coexpression network analysis (WGCNA) were applied to identify PRLs. The LASSO algorithm was employed to develop and validate a pyroptosis-related lncRNA signature (PRLS) in three independent cohorts. The molecular characteristics, clinical significances, tumor microenvironment, immune checkpoints profiles, and benefits of chemotherapy and immunotherapy regarding to PRLS were also explored.

Results: In the WGCNA framework, a key module that highly correlated with pyroptosis was extracted for identifying PRLs. Univariate Cox analysis further revealed the associations between PRLs and overall survival. Based on the expression profiles of PRLs, the PRLS was initially developed in TCGA cohort (n = 143) and then validated in two CGGA cohorts (n = 374). Multivariate Cox analysis demonstrated that our PRLS model was an independent risk factor. More importantly, this signature displayed a stable and accurate performance in predicting prognosis at 1, 3, and 5 years, with all AUCs above 0.7. The decision curve analysis also indicated that our signature had promising clinical application. In addition, patients with high PRLS score suggested a more abundant immune infiltration, higher expression of immune checkpoint genes, and better response to immunotherapy but worse to chemotherapy.

Conclusion: A novel pyroptosis-related lncRNA signature with a robust performance was constructed and validated in multiple cohorts. This signature provided new perspectives for clinical management and precise treatments of GBM.

miR-671-5p Inhibition by MSI1 Promotes Glioblastoma Tumorigenesis via Radioresistance, Tumor Motility and Cancer Stem-like Cell Properties

MicroRNAs (miRNAs) could be potential biomarkers for glioblastoma multiforme (GBM) prognosis and response to therapeutic agents. We previously demonstrated that the cancer stem cell marker Musashi-1 (MSI1) is an RNA binding protein that promotes radioresistance by increasing downstream RNA stability. To identify that MSI1 interacts with miRNAs and attenuates their function, we also get candidate miRNAs from the mRNA seq by predicting with TargetScan software. miR-671-5p in GBM cells interacts with MSI1 by intersecting the precipitated miRNAs with the predicted miRNAs. Notably, overexpression of MSI1 reversed the inhibitory effect of miR-671-5p. The phenotype of miR-671-5p in GBM cells could affect radiosensitivity by modulating the posttranscriptional activity of STAT3. In addition, miR-671-5p could attenuate tumor migration and cancer stem cell (CSC) characteristics by repressing the posttranscriptional activity of TRAF2. MSI1 may regulate GBM radioresistance, CSCs and tumor motility through miR-671-5p inhibition to increasing STAT3 and TRAF2 presentation. In vivo, the GBM tumor size was inversely correlated with miR-671-5p expression, but tumorigenesis was promoted by STAT3 and TRAF2 activation in the miR-671-5p-positive GBM population. miR-671-5p could be activated as a novel therapeutic target for GBM and has potential application as a predictive biomarker of glioblastoma prognosis.

Brain Tumors and Circulating microRNAs: A Systematic Review and Diagnostic Meta-Analysis

PURPOSE

Brain tumors (BT) are among the most prevalent cancers in recent years. Various studies have examined the diagnostic role of microRNAs in different diseases; however, their diagnostic role in BT has not been comprehensively investigated. Therefore, this meta-analysis was performed to assess microRNAs in the blood of patients with BTs accurately.

METHODS

Twenty-six eligible studies were included for analysis. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), area under curve (AUC), Q*index, summary receiver-operating characteristic (SROC) were assessed using the Meta-Disc V.1.4 and Comprehensive Meta-Analysis V.3.3 software. The Egger's test was used to evaluate publication bias in this study.

RESULTS

The diagnostic accuracy of microRNA was high in identifying BT based on the pooled sensitivity 0.82 (95% CI: 0.816 - 0.84), specificity 0.82 (95% CI: 0.817 - 0.84), PLR 5.101 (95% CI: 3.99 - 6.51), NLR 0.187 (95% CI: 0.149 - 0.236), DOR 34.07 (95% CI: 22.56 - 51.43) as well as AUC (0.92), and Q*-index (0.86). Subgroup analyses was also performed for sample types (serum/plasma), reference genes (RNU6, miR-39, and miR-24), and region to determine the diagnostic power of microRNAs in the diagnosis of BT using pooled sensitivity, specificity, PLR, NLR, AUC, and DOR.

CONCLUSION

This meta-analysis proved that circulating microRNAs were the potential markers for BT and could potentially be used as non-invasive early detection biomarkers.

Sevoflurane inhibits progression of glioma via regulating the HMMR antisense RNA 1/microRNA-7/cyclin dependent kinase 4 axis

Sevoflurane (Sev) is a volatile anesthetic that can inhibit tumor malignancy. Glioma is a main brain problem, but the mechanism of Sev in glioma progression is largely unclear. This study aims to explore a potential regulatory network of long noncoding RNA (lncRNA)/microRNA (miRNA)/mRNA associated with the function of Sev in glioma progression. LncRNA HMMR antisense RNA 1 (HMMR-AS1), miR-7 and cyclin-dependent kinase 4 (CDK4) abundances were examined via quantitative reverse transcription polymerase chain reaction and western blot. Cell viability, invasion, and colony formation ability were analyzed via cell counting kit-8, transwell analysis, and colony formation. The target association was analyzed via dual-luciferase reporter analysis and RNA pull-down. The in vivo function of Sev was investigated by xenograft model. HMMR-AS1 abundance was increased in glioma tissues and cells, and reduced via Sev. Sev constrained cell viability, invasion, and colony formation ability via decreasing HMMR-AS1 in glioma cells. miR-7 expression was decreased in glioma, and was targeted via HMMR-AS1. HMMR-AS1 silence restrained cell viability, invasion, and colony formation ability by up-regulating miR-7 in glioma cells. Sev increases miR-7 abundance via decreasing HMMR-AS1. CDK4 was targeted via miR-7, and highly expressed in glioma. miR-7 overexpression inhibited cell viability, invasion, and colony formation ability via reducing CDK4 in glioma cells. CDK4 expression was reduced by Sev via HMMR-AS1/miR-7 axis. Sev suppressed cell growth in glioma by regulating HMMR-AS1. Sev represses glioma cell progression by regulating HMMR-AS1/miR-7/CDK4 axis.

MicroRNA-3148 inhibits glioma by decreasing DCUN1D1 and inhibiting the NF-kB pathway

Glioma, which originates in the brain, is the most aggressive tumor of the central nervous system. It has been shown that microRNA (miRNA) controls the proliferation, migration and apoptosis of glioma cells. The objective of the present study was to measure microRNA-3148 (miR-3148) expression and investigate its impact on the pathogenetic mechanism of glioma. In the present study, reverse transcription-quantitative real-time PCR was employed to detect miR-3148 expression levels in glioma tissues and cell lines. Cell Counting Kit-8 assay, 5-ethynyl-2'-deoxyuridine assay, and Transwell migration assay were performed to assess the influence of miR-3148 on the malignant biological behavior of glioma cells. The biological functions of miR-3148 in glioma were examined via a xenograft tumor growth assay. Furthermore, the association between miR-3148 and DCUN1D1 was investigated via immunohistochemistry, dual-luciferase reporter assay and western blotting. It was observed that miR-3148 was expressed at low levels in glioma cells, and this represented a poor survival rate. In addition, an increased level of miR-3148 in cells and animal models inhibited glioma cell migration and proliferation. Moreover, miR-3148 decreased DCUN1D1 and curbed the nuclear factor κ enhancer binding protein (NF-κB) signaling pathway, thus decreasing the growth of glioma. Thus, miR-3148 is expressed within glioma tissues at low levels where it suppresses glioma by curbing the NF-κB pathway and lowering DCUN1D1.

Small nucleolar RNAs in plasma extracellular vesicles and their discriminatory power as diagnostic biomarkers of Alzheimer's disease

The clinical diagnosis of Alzheimer's disease, at its early stage, remains a difficult task. Advanced imaging technologies and laboratory assays to detect Aβ peptides Aβ42 and Aβ40, total and phosphorylated tau in CSF provide a set of biomarkers of developing AD brain pathology and facilitate the diagnostic process. The search for biofluid biomarkers, other than in CSF, and the development of biomarker assays have accelerated significantly and now represent the fastest-growing field in AD research. The goal of this study was to determine the differential enrichment of noncoding RNAs (ncRNAs) in plasma-derived extracellular vesicles (EV) of AD patients and Cognitively Normal controls (NC). Using RNA-seq, we profiled four significant classes of ncRNAs: miRNAs, snoRNAs, tRNAs, and piRNAs. We report a significant enrichment of SNORDs - a group of snoRNAs, in AD samples compared to NC. To verify the differential enrichment of two clusters of SNORDs - SNORD115 and SNORD116, localized on human chromosome 15q11-q13, we used plasma samples of an independent group of AD patients and NC. We applied ddPCR technique and identified SNORD115 and SNORD116 with a high discriminatory power to differentiate AD samples from NC. The results of our study present evidence that AD is associated with changes in the enrichment of SNORDs, transcribed from imprinted genomic loci, in plasma EV and provide a rationale to further explore the validity of those SNORDs as plasma biomarkers of AD.

Non-Coding RNAs: Emerging Therapeutic Targets in Spinal Cord Ischemia-Reperfusion Injury

Paralysis or paraplegia caused by transient or permanent spinal cord ischemia–reperfusion injury (SCIRI) remains one of the most devastating post-operative complications after thoracoabdominal aortic surgery, even though perioperative strategies and surgical techniques continue to improve. Uncovering the molecular and cellular pathophysiological processes in SCIRI has become a top priority. Recently, the expression, function, and mechanism of non-coding RNAs (ncRNAs) in various diseases have drawn wide attention. Non-coding RNAs contain a variety of biological functions but do not code for proteins. Previous studies have shown that ncRNAs play a critical role in SCIRI. However, the character of ncRNAs in attenuating SCIRI has not been systematically summarized. This review article will be the first time to assemble the knowledge of ncRNAs regulating apoptosis, inflammation, autophagy, and oxidative stress to attenuate SCIRI. A better understanding of the functional significance of ncRNAs following SCIRI could help us to identify novel therapeutic targets and develop potential therapeutic strategies. All the current research about the function of nRNAs in SCIRI will be summarized one by one in this review.

Histone demethylase JMJD1C promotes the polarization of M1 macrophages to prevent glioma by upregulating miR-302a

Glioma is regarded as an aggressive lethal primary brain tumor. Jumonji domain containing 1C (JMJD1C) is a H3K9 demethylase which participates in the progression of various tumors, but its specific function and underlying mechanism in glioma development remain undefined, which is the purpose of our work. We initially assessed JMJD1C expression in glioma tissues and cells using the assays of RT-qPCR and immunohistochemistry. Meanwhile, the H3K9 level at the microRNA (miR)-302a promoter region was measured by chromatin immunoprecipitation assay, while luciferase-based reporter assay was performed for validation of the binding affinity between miR-302a and methyltransferase-like 3 (METTL3). The effect of METTL3 on suppressor of cytokine signaling 2 (SOCS2) was subsequently analyzed by MeRIP-RT-qPCR. Finally, a xenograft tumor model was established in nude mice, followed by measurement of tumor-associated macrophages using flow cytometry. JMJD1C was poorly expressed in glioma tissues. Furthermore, JMJD1C increased miR-302a expression through promoting H3K9me1 demethylation at the miR-302a promoter region. miR-302a was identified to target METTL3, which could inhibit SOCS2 expression via m6A modification. JMJD1C promoted M1 macrophage polarization and suppressed the growth of glioma xenografts through the miR-302a/METTL3/SOCS2 axis both in vivo and in vitro. In conclusion, JMJD1C could enhance M1 macrophage polarization to inhibit the onset of glioma, bringing a new insight into the contribution of JMJD1C to the pathobiology of glioma, with possible implications for targeted therapeutic method.

Naringenin attenuates cell viability and migration of C6 glioblastoma cell line: a possible role of hedgehog signaling pathway

OBJECTIVE

Gliomas are the most prevalent type of malignant primary brain tumors. Despite the availability of several treatment modalities, these tumors have poor prognostic features. Aberrant Hedgehog (Hh) signaling has been found to be implicated in the development of numerous malignancies including gliomas. Naringenin appears to have anti-proliferative and anti-cancer properties. However, there is no report describing its effects via the Hh signaling pathway on the C6 glioblastoma cell line. The current study was set to examine the anti-cancer effects of naringenin on C6 cells in order to determine the effect of this compound on the Hh signaling pathway.

METHODS

The anti-proliferative and apoptotic effects of naringenin against C6 and 3T3 fibroblast cells were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and annexin-V/PI dual staining assay, respectively. The effect of naringenin on the migration of C6 cells was evaluated by the migration scratch assay. To assess the anti-cancer effect of naringenin on the Hh signaling pathway, the expression of Gli-1, Smo, and Sufu at protein levels in C6 cells was analyzed using western blotting.

RESULTS

The obtained data indicated that naringenin exerted higher cytotoxicity against C6 cells (IC50 value of 114 ± 3.4 µg/mL) than normal 3T3 fibroblasts (IC50 value of 290 ± 7 µg/mL). Naringenin (114 µg/mL) also induced stronger apoptotic effects on C6 cells than 3T3 cells after 24 h of incubation. Furthermore, naringenin at a concentration of 114 µg/mL and a lower concentration of 60 µg/mL inhibited the migration of the C6 cell line. In addition, naringenin at a concentration of 114 µg/mL significantly decreased the expression of Gli-1 and Smo and elevated the expression of Sufu at the protein level in the C6 cell line.

CONCLUSION

These data represent that naringenin may have a potential effect on the management of the proliferation and metastasis of malignant gliomas by inhibiting the Hh signaling pathway.

Circ_CLIP2 promotes glioma progression through targeting the miR-195-5p/HMGB3 axis

BACKGROUND

Circular RNA (circRNA) has been demonstrated to play key roles in regulating glioma progression. Understanding the regulatory mechanism of circRNA in glioma is vital to reveal the pathogenesis of glioma and develop novel therapeutic strategies. Therefore, our study focuses on the role and underlying mechanism of Circ_CLIP2 in glioma.

METHODS

The expression of Circ_CLIP2, miR-195-5p and HMGB3 in glioma cells and tissues were analyzed using qRT-PCR. Cell proliferation was determined with colony formation and MTT assays. Cell cycle and apoptosis were examined by flow cytometry. Western blot was conducted for analyzing HMGB3, PCNA, Bax, Bcl-2, cleaved-caspase 3, Wnt-1 and β-catenin. Dual-luciferase reporter assay was measured to investigate the interaction among Circ_CLIP2, miR-195-5p and HMGB3.

RESULTS

The expression of Circ_CLIP2 and HMGB3 were increased while miR-195-5p was down-regulated in glioma cells and patients. Silencing of Circ_CLIP2 inhibited cell proliferation, enhanced cell apoptosis and inhibited the Wnt/β-catenin signaling pathway. Circ_CLIP2 suppressed miR-195-5p expression by directly sponging miR-195-5p. MiR-195-5p inhibited HMGB3 expression via directly targeting HMGB3. Knockdown of miR-195-5p facilitated cell proliferation, inhibited cell apoptosis and activated Wnt/β-catenin signaling, which were reversed by silencing of HMGB3.

CONCLUSION

Knockdown of Circ_CLIP2 suppresses glioma progression by targeting miR-195-5p/HMGB3 thus inhibiting Wnt/β-catenin signaling. This study may provide potential therapeutic targets against glioma.

Aberrant hypermethylation induced downregulation of antisense lncRNA STXBP5-AS1 and its sense gene STXBP5 correlate with tumorigenesis of glioma

AIMS

The expression of antisense lncRNA STXBP5-AS1 and its sense gene STXBP5 were found to be downregulated in glioma by RNA sequencing; however, the function and mechanism of both two genes in the development of glioma have not been studied.

MATERIALS AND METHODS

QRT-PCR and western blot were used to determine the transcriptional and translational levels of moleculars. MSP and BSP assays were used to evaluate the methylation status of promoter CpG island. MTT, EdU, flow cytometry, and transwell assays were used to reveal biological effects. The in vivo mice model was used to validate the role of target genes in tumorigenesis.

KEY FINDINGS

The mRNA and protein expression of STXBP5 was significantly downregulated in glioma tissues and positively correlated with prognosis. STXBP5-AS1 was downregulated in glioma cells and tissues, and associated with tumor size and clinical stages. Both of two genes were significantly restored in cells treatment with 5-Aza. The promoter CpG island of STXBP5/STXBP5-AS1 was hypermethylated in glioma cells, but partially methylated in NHA cells. We found that promoter methylation frequency was significantly higher in glioma tissues. Functionally, overexpression of STXBP5 and STXBP5-AS1 inhibited cell proliferation, migration, and invasion and promoted apoptosis in vitro, whereas depletion of STXBP5 and STXBP5-AS1 showed opposite effects. Both the mRNA and protein expression of STXBP5 were positively regulated by STXBP5-AS1. Ectopic expression of STXBP5 and STXBP5-AS1 suppressed tumor formation in vivo.

SIGNIFICANCE

Our findings suggested that epigenetically silenced STXBP5-AS1 and STXBP5 might act as novel tumor suppressors of glioma.

Role of mammalian long non-coding RNAs in normal and neuro oncological disorders

Long non-coding RNAs (lncRNAs) are expressed at lower levels than protein-coding genes but have a crucial role in gene regulation. LncRNA is distinct, they are being transcribed using RNA polymerase II, and their functionality depends on subcellular localization. Depending on their niche, they specifically interact with DNA, RNA, and proteins and modify chromatin function, regulate transcription at various stages, forms nuclear condensation bodies and nucleolar organization. lncRNAs may also change the stability and translation of cytoplasmic mRNAs and hamper signaling pathways. Thus, lncRNAs affect the physio-pathological states and lead to the development of various disorders, immune responses, and cancer. To date, ~40% of lncRNAs have been reported in the nervous system (NS) and are involved in the early development/differentiation of the NS to synaptogenesis. LncRNA expression patterns in the most common adult and pediatric tumor suggest them as potential biomarkers and provide a rationale for targeting them pharmaceutically. Here, we discuss the mechanisms of lncRNA synthesis, localization, and functions in transcriptional, post-transcriptional, and other forms of gene regulation, methods of lncRNA identification, and their potential therapeutic applications in neuro oncological disorders as explained by molecular mechanisms in other malignant disorders.

Nanoribbon-Based Electronic Detection of a Glioma-Associated Circular miRNA

Nanoribbon chips, based on “silicon-on-insulator” structures (SOI-NR chips), have been fabricated. These SOI-NR chips, whose surface was sensitized with covalently immobilized oligonucleotide molecular probes (oDNA probes), have been employed for the nanoribbon biosensor-based detection of a circular ribonucleic acid (circRNA) molecular marker of glioma in humans. The nucleotide sequence of the oDNA probes was complimentary to the sequence of the target oDNA. The latter represents a synthetic analogue of a glioma marker—NFIX circular RNA. In this way, the detection of target oDNA molecules in a pure buffer has been performed. The lowest concentration of the target biomolecules, detectable in our experiments, was of the order of ~10⁻¹⁷ M. The SOI-NR sensor chips proposed herein have allowed us to reveal an elevated level of the NFIX circular RNA in the blood of a glioma patient.

The pseudogene PRELID1P6 promotes glioma progression via the hnHNPH1-Akt/mTOR axis

Research over the past decade has suggested important roles for pseudogenes in glioma. This study aimed to show that pseudogene PRELI domain-containing 1 pseudogene 6 (PRELID1P6) promotes glioma progression. Aberrant expression of genes was screened using The Cancer Genome Atlas database. We found that mRNA level of PRELID1P6 was highly upregulated in glioma and was associated with a shorter survival time. Functional studies showed that the knockdown of PRELID1P6 decreased cell proliferation, sphere formation, and clone formation ability and blocked the cell cycle transition at G0/G1, while overexpression of PRELID1P6 had the opposite effects. Mechanistically, knockdown of PRELID1P6 changed the cellular localization of heterogeneous nuclear ribonucleoprotein H1 (hnRNPH1) from nucleus to cytoplasm, which promoted ubiquitin-mediated degradation of hnRNPH1. RNA-sequence and gene set enrichment analysis suggested that knockdown of PRELID1P6 regulates the apoptosis signaling pathway. Western blotting showed that PRELID1P6 increased TRF2 expression by hnRNPH1-mediated alternative splicing effect and activated the Akt/mTOR pathway. Furthermore, Akt inhibitor MK2206 treatment reversed the oncogenic function of PRELID1P6. PRELID1P6 was also found to be negatively regulated by miR-1825. Our result showed that PRELID1P6 promotes glioma progression through the hnHNPH1-Akt/mTOR pathway. These findings shed new light on the important role of PRELID1P6 as a novel oncogene for glioma.

Pro- and Antiangiogenic Factors in Gliomas: Implications for Novel Therapeutic Possibilities

Angiogenesis, a complex, multistep process of forming new blood vessels, plays crucial role in normal development, embryogenesis, and wound healing. Malignant tumors characterized by increased proliferation also require new vasculature to provide an adequate supply of oxygen and nutrients for developing tumor. Gliomas are among the most frequent primary tumors of the central nervous system (CNS), characterized by increased new vessel formation. The processes of neoangiogenesis, necessary for glioma development, are mediated by numerous growth factors, cytokines, chemokines and other proteins. In contrast to other solid tumors, some biological conditions, such as the blood–brain barrier and the unique interplay between immune microenvironment and tumor, represent significant challenges in glioma therapy. Therefore, the objective of the study was to present the role of various proangiogenic factors in glioma angiogenesis as well as the differences between normal and tumoral angiogenesis. Another goal was to present novel therapeutic options in oncology approaches. We performed a thorough search via the PubMed database. In this paper we describe various proangiogenic factors in glioma vasculature development. The presented paper also reviews various antiangiogenic factors necessary in maintaining equilibrium between pro- and antiangiogenic processes. Furthermore, we present some novel possibilities of antiangiogenic therapy in this type of tumors.

miR-1258 Attenuates Tumorigenesis Through Targeting E2F1 to Inhibit PCNA and MMP2 Transcription in Glioblastoma

MicroRNAs are a group of endogenous small non-coding RNAs commonly dysregulated in tumorigenesis, including glioblastoma (GBM), the most malignant brain tumor with rapid proliferation, diffuse invasion, and therapeutic resistance. Accumulating evidence has manifested that miR-1258 exerts an inhibitory role in many human cancers. However, the expression pattern of miR-1258 and its potential function in GBM tumorigenesis remain unclear. In this study, we reported that miR-1258 expression decreased with the ascending pathological grade of glioma, which indicated an unfavorable prognosis of patients. Functional assays revealed an inhibitory effect of miR-1258 on malignant proliferation, therapeutic resistance, migration, and invasion of GBM in vitro. Moreover, xenograft models also suggested a repression effect of miR-1258 on gliomagenesis. Mechanistically, miR-1258 directly targeted E2F1 in 3’-untranslated regions and attenuated E2F1-mediated downstream gene PCNA and MMP2 transcriptions. Furthermore, restoration of E2F1 expression in GBM cells effectively rescued the tumor-suppressive effect of miR-1258. Our studies illustrated that miR-1258 functioned as a tumor suppressor in GBM by directly targeting E2F1, subsequently inhibiting PCNA and MMP2 transcriptions, which contributed to new potential targets for GBM therapy and other E2F1-driven cancers.

Inhibiting proliferation and metastasis of osteosarcoma cells by downregulation of long non-coding RNA colon cancer-associated transcript 2 targeting microRNA-143

Osteosarcoma is a malignant bone tumor, which has a high incidence in children and adolescents. However, the pathogenesis of osteosarcoma remains unclear. Long noncoding RNA (lncRNA) is a new potential therapeutic target and diagnostic biomarker for osteosarcoma. Hence, the present study aimed to explore the effect of lncRNA colon cancer-associated transcript (CCAT2) on osteosarcoma and its potential underlying mechanisms. For this purpose, the proliferation of osteosarcoma cells was measured using the CCK-8 assay. The scratch-wound and cell invasion assays were used to determine the migration and invasion of osteosarcoma cells, respectively. LncRNA CCAT2 and microRNA (miR)-143 binding sites were identified by the dual-luciferase reporter assay. RNA and protein expression levels were detected by reverse-transcription quantitative PCR and western blotting, respectively. Downregulation of lncRNA CCAT2 inhibited the proliferation, migration, and invasion of osteosarcoma cells. The findings also revealed that miR-143 bound directly to lncRNA CCAT2. The expression of miR-143 was upregulated by the knockdown of lncRNA CCAT2. Downregulation of the FOS-like antigen 2 was also observed after knockdown of lncRNA CCAT2. The function of lncRNA CCAT2 in osteosarcoma cells was attenuated by co-transfection with anti-miR-143 oligodeoxyribonucleotide. In conclusion, downregulation of lncRNA CCAT2 inhibited the proliferation and metastasis of osteosarcoma cells by targeting miR-143. lncRNA CCAT2 was identified as a potential target for osteosarcoma treatment.