Non-coding RNAs in Brain Tumors, the Contribution of lncRNAs, circRNAs, and snoRNAs to Cancer Development-Their Diagnostic and Therapeutic Potential

The Association Between Functional Variants in Long Non-coding RNAs and the Risk of Autism Spectrum Disorder Was Not Mediated by Gut Microbiota

The effect of functional variants in long non-coding RNA (lncRNA) gene regions on autism spectrum disorder (ASD) remains unclear. The present study aimed to investigate the association of functional variants located in lncRNA genes with the risk of ASD and explore whether gut microbiota would mediate the relationship. A total of 87 cases and 71 healthy controls were enrolled in the study. MassARRAY platform and 16S rRNA sequencing were respectively applied to assess the genotype of candidate SNPs and gut microbiota of children. The logistic regression models showed that the association between rs2295412 and the risk of ASD was statistically significant after Bonferroni adjustments. The risk of ASD decreased by 19% for each additional C allele carried by children in multiplicative models (OR = 0.81, 95% CI, 0.69-0.94, P = 0.007). Although we identified significant correlations between rs8113922 polymorphisms, Bifidobacteriales, and ASD, the mediating effect of gut microbiota on the relationship of the polymorphisms with the risk of ASD was not significant. The findings demonstrated that functional variants in lncRNA genes play an important role in ASD and gut microbiota could not mediate the association. Future studies are warranted to verify the results and search for more possible mechanisms of variants located in lncRNA genes implicated in ASD.

Fundamental Neurochemistry Review: At the intersection between the brain and the immune system: Non-coding RNAs spanning learning, memory and adaptive immunity

Non-coding RNAs (ncRNAs) are highly plastic RNA molecules that can sequester cellular proteins and other RNAs, serve as transporters of cellular cargo and provide spatiotemporal feedback to the genome. Mounting evidence indicates that ncRNAs are central to biology, and are critical for neuronal development, metabolism and intra- and intercellular communication in the brain. Their plasticity arises from state-dependent dynamic structure states that can be influenced by cell type and subcellular environment, which can subsequently enable the same ncRNA with discrete functions in different contexts. Here, we highlight different classes of brain-enriched ncRNAs, including microRNA, long non-coding RNA and other enigmatic ncRNAs, that are functionally important for both learning and memory and adaptive immunity, and describe how they may promote cross-talk between these two evolutionarily ancient biological systems.

Hidden regulators: the emerging roles of lncRNAs in brain development and disease

Long non-coding RNAs (lncRNAs) have emerged as critical players in brain development and disease. These non-coding transcripts, which once considered as "transcriptional junk," are now known for their regulatory roles in gene expression. In brain development, lncRNAs participate in many processes, including neurogenesis, neuronal differentiation, and synaptogenesis. They employ their effect through a wide variety of transcriptional and post-transcriptional regulatory mechanisms through interactions with chromatin modifiers, transcription factors, and other regulatory molecules. Dysregulation of lncRNAs has been associated with certain brain diseases, including Alzheimer's disease, Parkinson's disease, cancer, and neurodevelopmental disorders. Altered expression and function of specific lncRNAs have been implicated with disrupted neuronal connectivity, impaired synaptic plasticity, and aberrant gene expression pattern, highlighting the functional importance of this subclass of brain-enriched RNAs. Moreover, lncRNAs have been identified as potential biomarkers and therapeutic targets for neurological diseases. Here, we give a comprehensive review of the existing knowledge of lncRNAs. Our aim is to provide a better understanding of the diversity of lncRNA structure and functions in brain development and disease. This holds promise for unravelling the complexity of neurodevelopmental and neurodegenerative disorders, paving the way for the development of novel biomarkers and therapeutic targets for improved diagnosis and treatment.

Immunological processes of enhancers and suppressors of long non-coding RNAs associated with brain tumors and inflammation

Immunological processes, such as inflammation, can both cause tumor suppression and cancer progression. Moreover, deregulated levels of long non-coding RNA (lncRNA) expression in the brain may cause inflammation and lead to the growth of tumors. Like other biological processes, the immune system's role in cancer is complicated, varies, and can help or hurt the cancer's maintenance. According to research, inflammation and brain cancer are correlated via several signaling pathways. A variety of lncRNAs have recently been revealed to influence cancer by modulating inflammatory pathways. As a result, lncRNAs have the potential to influence carcinogenesis, tumor formation, or tumor suppression via an increase or decrease in inflammation functions. Although the study and targeting of lncRNAs have made great progress in the treatment of cancer, there are definitely limitations and challenges. Using new technologies like nanocarriers and cell-penetrating peptides (CPPs) to target treatments without hurting healthy body tissues has shown to be very effective. In this review article, we have collected significantly related lncRNAs and their inhibitory or stimulating roles in inflammation and brain cancer for the first time. However, there are limitations, such as side effects and damage to normal tissues. With the advancement of new targeting technologies, these lncRNAs may be candidates for the specific targeting therapy of brain cancers by limiting inflammation or stimulating the immune system against them in the future.

CircGPC3 promotes hepatocellular carcinoma progression and metastasis by sponging miR-578 and regulating RAB7A/PSME3 expression

CircRNAs are a class of highly stable noncoding RNAs that play an important role in the progression of many diseases, especially cancer. In this study, high-throughput sequencing was used to screen for abnormally expressed circRNAs, and we found that circGPC3 was overexpressed in HCC tissues. However, the underlying mechanism of circGPC3 in the development and metastasis of hepatocellular carcinoma (HCC) remains unknown. In our study, we found that circGPC3 was significantly upregulated in HCC tissues and cells and that its overexpression was positively correlated with overall survival, TNM stage and lymph node metastasis. In vivo and in vitro experiments showed that circGPC3 knockdown repressed HCC cell migration, invasion and proliferation and promoted apoptosis. Mechanistically, circGPC3 promoted HCC proliferation and metastasis through the miR-578/RAB7A/PSME3 axis. Our results demonstrate that circGPC3 contributes to the progression of HCC and provides an intervention target for HCC.

The Role of the Dysregulation of Long Non-Coding and Circular RNA Expression in Medulloblastoma: A Systematic Review

Medulloblastoma (MB) is the most common malignant brain tumor in childhood. Although recent multi-omic studies have led to advances in MB classification, there is still room for improvement with regard to treatment response and survival. Therefore, identification of new and less invasive biomarkers is needed to refine the diagnostic process and to develop more personalized treatment strategies. In this context, non-coding RNAs (ncRNAs) could be useful biomarkers for MB. In this article, we reviewed the role of two types of ncRNAs, long non-coding (lncRNAs) and circular RNAs (circRNAs), as biomarkers for the diagnosis, subgroup classification, and prognosis of MB. We also reviewed potential candidates with specific functions and mechanisms of action in the disease. We performed a search in PubMed and Scopus using the terms ("long non coding RNAs" OR "lncRNAs") and ("circular RNAs" OR "circRNAs") AND "medulloblastoma" to identify biomarker discovery or functional studies evaluating the effects of these ncRNAs in MB. A total of 26 articles met the inclusion criteria. Among the lncRNAs, the tumorigenic effects of the upregulated lnc-IRX3-80 and lnc-LRRC47-78 were the most studied in MB. Among the circRNAs, the upregulation of circSKA3 and its functional impact in MB cell lines were the most consistent results, so this circRNA could be considered a potential biomarker in MB. Additional validation is required for many deregulated lncRNAs and circRNAs; therefore, further studies are warranted.

Data Mining of Microarray Datasets in Translational Neuroscience

Data mining involves the computational analysis of a plethora of publicly available datasets to generate new hypotheses that can be further validated by experiments for the improved understanding of the pathogenesis of neurodegenerative diseases. Although the number of sequencing datasets is on the rise, microarray analysis conducted on diverse biological samples represent a large collection of datasets with multiple web-based programs that enable efficient and convenient data analysis. In this review, we first discuss the selection of biological samples associated with neurological disorders, and the possibility of a combination of datasets, from various types of samples, to conduct an integrated analysis in order to achieve a holistic understanding of the alterations in the examined biological system. We then summarize key approaches and studies that have made use of the data mining of microarray datasets to obtain insights into translational neuroscience applications, including biomarker discovery, therapeutic development, and the elucidation of the pathogenic mechanisms of neurodegenerative diseases. We further discuss the gap to be bridged between microarray and sequencing studies to improve the utilization and combination of different types of datasets, together with experimental validation, for more comprehensive analyses. We conclude by providing future perspectives on integrating multi-omics, to advance precision phenotyping and personalized medicine for neurodegenerative diseases.

Roles of lncRNAs in brain development and pathogenesis: Emerging therapeutic opportunities

The human genome is pervasively transcribed, producing a majority of short and long noncoding RNAs (lncRNAs) that can influence cellular programs through a variety of transcriptional and post-transcriptional regulatory mechanisms. The brain houses the richest repertoire of long noncoding transcripts, which function at every stage during central nervous system development and homeostasis. An example of functionally relevant lncRNAs is species involved in spatiotemporal organization of gene expression in different brain regions, which play roles at the nuclear level and in transport, translation, and decay of other transcripts in specific neuronal sites. Research in the field has enabled identification of the contributions of specific lncRNAs to certain brain diseases, including Alzheimer's disease, Parkinson's disease, cancer, and neurodevelopmental disorders, resulting in notions of potential therapeutic strategies that target these RNAs to recover the normal phenotype. Here, we summarize the latest mechanistic findings associated with lncRNAs in the brain, focusing on their dysregulation in neurodevelopmental or neurodegenerative disorders, their use as biomarkers for central nervous system (CNS) diseases in vitro and in vivo, and their potential utility for therapeutic strategies.

Clinical, Histological, and Molecular Prognostic Factors in Childhood Medulloblastoma: Where Do We Stand?

Medulloblastomas, highly aggressive neoplasms of the central nervous system (CNS) that present significant heterogeneity in clinical presentation, disease course, and treatment outcomes, are common in childhood. Moreover, patients who survive may be diagnosed with subsequent malignancies during their life or could develop treatment-related medical conditions. Genetic and transcriptomic studies have classified MBs into four subgroups: wingless type (WNT), Sonic Hedgehog (SHH), Group 3, and Group 4, with distinct histological and molecular profiles. However, recent molecular findings resulted in the WHO updating their guidelines and stratifying medulloblastomas into further molecular subgroups, changing the clinical stratification and treatment management. In this review, we discuss most of the histological, clinical, and molecular prognostic factors, as well the feasibility of their application, for better characterization, prognostication, and treatment of medulloblastomas.

Circular RNA CircPDS5B impairs angiogenesis following ischemic stroke through its interaction with hnRNPL to inactivate VEGF-A

BACKGROUND

Ischemic stroke (IS) is the primary cause of mortality and disability worldwide. Circular RNAs (circRNAs) have been proposed as crucial regulators in IS. This study focused on the role of circPDS5B in IS and its underlying mechanism.

METHOD

Transient middle cerebral artery occlusion (tMCAO) mice and glucose deprivation/reoxygenation (OGD/R)-exposed human brain microvascular endothelial cells (BMECs) were used as IS models. Expression levels of circPDS5B, heterogenous nuclear ribonucleoprotein L (hnRNPL), runt-related transcription factor-1 (Runx1), and Zinc finger protein 24 (ZNF24) were quantified by qRT-PCR. MTT, wound healing, transwell and tube formation assays were employed to evaluate the cell proliferation, migration, and angiogenesis, respectively. Moreover, RNA pull-down, and RIP assay were performed to investigate the interaction among circPDS5B, hnRNPL and vascular endothelial growth factor-A (VEGFA).

RESULTS

circPDS5B was significantly up-regulated in IS patients and tMCAO mice. Deficiency of circPDS5B relieved brain infarction and neuronal injury of tMCAO mice. OGD/R-induced apoptosis, inhibition in viability, migration, and angiogenesis in BMECs were dramatically abrogated by circPDS5B knockdown. Mechanistically, circPDS5B stabilized Runx1 and ZNF24 via recruiting hnRNPL, thereby suppressing the transcription and expression of VEGFA. hnRNPL silencing strengthened circPDS5B knockdown-mediated beneficial effect on IS.

CONCLUSION

Altogether, our study showed that high expression of circPDS5B exacerbated IS through recruitment of hnRNP to stabilize Runx1/ZNF24 and subsequently inactivate VEGF-A. Our findings suggest circPDS5B may be a novel therapeutic target for IS.

lncRNA NEAT1/miR-495-3p regulates angiogenesis in burn sepsis through the TGF-β1 and SMAD signaling pathways

INTRODUCTION

To investigate the role of the long-chain noncoding RNA (lncRNA) nuclear enriched abundant transcript 1 (NEAT1) in the process of angiogenesis in human umbilical vein endothelial cells (HUVECs) and illustrate its potential role in burn sepsis (BS) pathogenesis.

METHODS

HUVECs were treated with BS patient serum or healthy control serum. NEAT1 shRNA, miR-495-3p mimics, and miR-495-3p inhibitor were transfected into HUVECs. NEAT1 and miR-495-3 levels in serum or HUVECs were detected using quantitative reverse transcription-polymerase chain reaction. Cell counting kit-8 and flow cytometry assays were used to explore the proliferation and apoptosis of HUVECs. The expression of vascular endothelial growth factor (VEGF) in the supernatant was detected using enzyme-linked immunosorbent assay. Tube formation of HUVECs was also analyzed. Western blot analysis was used to analyze signaling pathway proteins.

RESULTS

In HUVECs stimulated with BS patient serum, NEAT1 expression was increased, while miR-495-3p expression was decreased. In addition, NEAT1 silencing by specific shRNA inhibited cell proliferation, VEGF production, and tube formation under burn patient serum treatment, which decreased the TGFβ1/SMAD signaling pathway activation. Moreover, miR-495-3p minics inhibited angiogenesis and the activation of signaling pathways induced by NEAT1 shRNA. Furthermore, miR-495-3p inhobitor promoted angiogenesis in HUVECs and activated the TGFβ1/SMAD signaling pathway. In patients with BS, NEAT1 expression was significantly increased and miR-495-3p expression was decreased compared to healthy controls, and NEAT1 and miR-495-3p expression was associated with the clinical features of patients.

CONCLUSIONS

Our results indicate that lncRNA NEAT1 regulates angiogenesis and activates the TGFβ1/SMAD signaling pathway during the occurrence of BS.

Emerging role of lncRNA ELDR in development and cancer

Whole-genome sequencing and transcriptome analysis revealed more than 90% of the human genome transcribes noncoding RNAs including lncRNAs. From the beginning of the 21st century, lncRNAs have gained widespread attention as a new layer of regulation in biological processes. lncRNAs are > 200 nucleotides in size, transcribed by RNA polymerase II, and share many similarities with mRNAs. lncRNA interacts with DNA, RNA, protein, and miRNAs, thereby regulating many biological processes. In this review, we have focused mainly on LINC01156 [also known as the EGFR long non-coding downstream RNA (ELDR) or Fabl] and its biological importance. ELDR is a newly identified lncRNA and first reported in a mouse model, but it has a human homolog. The human ELDR gene is closely localized downstream of epidermal growth factor receptor (EGFR) gene at chromosome 7 on the opposite strand. ELDR is highly expressed in neuronal stem cells and associated with neuronal differentiation and mouse brain development. ELDR is upregulated in head and neck cancer, suggesting its role as an oncogene and its importance in prognosis and therapy. Publicly available RNA-seq data further support its oncogenic potential in different cancers. Here, we summarize all the aspects of ELDR in development and cancer, highlighting its future perspectives in the context of mechanism.

Exosomal circDNER enhances paclitaxel resistance and tumorigenicity of lung cancer via targeting miR-139-5p/ITGB8

BACKGROUND

Circular RNAs (circRNAs) are regarded as vital regulatory factors in various cancers. However, the biological functions of circDNER in the paclitaxel (PTX) resistance of lung cancer remain largely unexplored.

METHODS

Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to analyze circDNER, miR-139-5p, and ITGB8. Cell proliferation was assessed via colony formation and MTT assays. Cell apoptosis was evaluated by flow cytometry. Western blot was performed to assess protein expression. The targeted interaction among circDNER, miR-139-5p, and ITGB8 were validated using dual-luciferase reporter or RNA immunoprecipitation assays.

RESULTS

Inhibition of circDNER reduced IC50 of PTX, inhibited cell proliferation, invasion and migration, as well as promoted cell apoptosis in PTX-resistant lung cancer cells. Mechanistically, circDNER sponged miR-139-5p to upregulate ITGB8 expression. Overexpression of miR-139-5p reversed the biological functions mediated by circDNER in PTX-resistant lung cancer cells. MiR-139-5p overexpression suppressed PTX resistance and malignant behaviors of PTX-resistant lung cancer cells, with ITGB8 elevation rescued the impacts. Moreover, we demonstrated that circDNER was upregulated in plasma exosomes from lung cancer patients. The plasma exosomes derived from these patients are the key factors enhancing the migration and invasion potential of lung cancer cells.

CONCLUSION

The circDNER mediated miR-139-5p/ITGB8 axis suppresses lung cancer progression. Our findings suggest that circDNER might act as a potential prognostic biomarker and therapeutic target for lung cancer treatment.

Hsa_circ_0008344 Promotes Glioma Tumor Progression and Angiogenesis Presumably by Regulating miR-638/SZRD1 Pathway

Hsa_circRNA_0008344 (circ_0008344) is a new glioma-related circular RNA. Our study aims to explore its functions in glioma tumor progression. Real-time quantitative PCR and western blotting were used to detect RNA and protein abundances. RNase R assay, actinomycin D assay, and subcellular fractionation method were performed to identify the features of circ_0008344. Cell-counting kit-8, 5-ethynyl-2'-deoxyuridine assays, transwell assays, tube formation assay, flow cytometry, and nude mice xenograft tumor model were performed. Target relationship was predicted by bioinformatics algorithms and confirmed by dual-luciferase reporter assay. Abundances of circ_0008344 and SUZ RNA binding domain containing 1 (SZRD1) were highly elevated, while miR-638 was downregulated in glioma tumors and cells. Circ_0008344 was identified as a stable circRNA with a circular structure. Silencing circ_0008344 could restrain glioma proliferation, migration, invasion, and angiogenesis. Circ_0008344 functioned as a sponge for miR-638. The negative regulation of circ_0008344 knockdown on glioma progression and angiogenesis could be reversed by miR-638 inhibitor. SZRD1 was a target of miR-318, and its overexpression overturned the inhibition effect of miR-638 mimic on glioma progression and angiogenesis. Meanwhile, we confirmed that circ_0008344 knockdown inhibited SZRD1 expression, and its effect was reversed by miR-638 inhibitor. Also, circ_00008344 knockdown suppressed glioma tumor growth. Circ_0008344 might contribute to glioma progression through miR-638/SZRD1 axis, which might be a novel pathology and treatment target in glioma.

Transforming Growth Factor-Beta-Regulated LncRNA-MUF Promotes Invasion by Modulating the miR-34a Snail1 Axis in Glioblastoma Multiforme

Transforming growth factor beta (TGF-β)-regulated long-non-coding RNAs (lncRNAs) modulate several aspects of tumor development such as proliferation, invasion, metastasis, epithelial to mesenchymal transition (EMT), and drug resistance in various cancers, including Glioblastoma multiforme (GBM). We identified several novel differentially expressed lncRNAs upon TGF-β treatment in glioma cells using genome-wide microarray screening. We show that TGF-β induces lncRNA-MUF in glioma cells, and its expression is significantly upregulated in glioma tissues and is associated with poor overall survival of GBM patients. Knockdown of lncRNA-MUF reduces proliferation, migration, and invasion in glioma cells and sensitizes them to temozolomide (TMZ)-induced apoptosis. In addition, lncRNA-MUF downregulation impairs TGF-β-induced smad2/3 phosphorylation. In line with its role in regulating invasion, lncRNA-MUF functions as a competing endogenous RNA (ceRNA) for miR-34a and promotes Snail1 expression. Collectively, our findings suggest lncRNA-MUF as an attractive therapeutic target for GBM.

Unveiling a Ghost Proteome in the Glioblastoma Non-Coding RNAs

Glioblastoma is the most common brain cancer in adults. Nevertheless, the median survival time is 15 months, if treated with at least a near total resection and followed by radiotherapy in association with temozolomide. In glioblastoma (GBM), variations of non-coding ribonucleic acid (ncRNA) expression have been demonstrated in tumor processes, especially in the regulation of major signaling pathways. Moreover, many ncRNAs present in their sequences an Open Reading Frame (ORF) allowing their translations into proteins, so-called alternative proteins (AltProt) and constituting the “ghost proteome.” This neglected world in GBM has been shown to be implicated in protein–protein interaction (PPI) with reference proteins (RefProt) reflecting involvement in signaling pathways linked to cellular mobility and transfer RNA regulation. More recently, clinical studies have revealed that AltProt is also involved in the patient’s survival and bad prognosis. We thus propose to review the ncRNAs involved in GBM and highlight their function in the disease.

Methyltransferase-Like 3-Mediated m6A Methylation of Hsa_circ_0058493 Accelerates Hepatocellular Carcinoma Progression by Binding to YTH Domain-Containing Protein 1

Circular RNAs (circRNAs) are highly correlated with the progression and prognosis of hepatocellular carcinoma (HCC). In addition, mounting evidence has revealed that N6-methyladenosine (m6A) methylation, a common RNA modification, is involved in the progression of malignancies. In this research, a novel circRNA, hsa_circ_0058493, was proven to be upregulated in HCC, which was correlated with the prognosis of HCC patients. Experimentally, hsa_circ_0058493 knockdown suppressed the growth and metastasis of HCC cells in vivo and in vitro. On the contrary, the overexpression of hsa_circ_0058493 in HCC cells had the opposite effect in vitro. Mechanistic experiments revealed that hsa_circ_0058493 contained m6A methylation sites and that methyltransferase-like 3 (METTL3) mediated the degree of methylation modification of hsa_circ_0058493. Furthermore, YTH domain-containing protein 1 (YTHDC1) could bind to hsa_circ_0058493 and promote its intracellular localization from the nucleus to the cytoplasm. In addition, both si-METTL3 and si-YTHDC1 suppressed HCC cell growth and metastasis, whereas rescue experiments confirmed that overexpression of hsa_circ_0058493 inverted the inhibitory effects of si-METTL3 and si-YTHDC1 on HCC cells. Taken together, this study explored the oncogenic role of m6A-modified hsa_circ_0058493 and found to accelerate HCC progression via the METTL3-hsa_circ_0058493-YTHDC1 axis, indicating a potential therapeutic target for this deadly disease.

Non-coding RNAs and their bioengineering applications for neurological diseases

Engineering of cellular biomolecules is an emerging landscape presenting creative therapeutic opportunities. Recently, several strategies such as biomimetic materials, drug-releasing scaffolds, stem cells, and dynamic culture systems have been developed to improve specific biological functions, however, have been confounded with fundamental and technical roadblocks. Rapidly emerging investigations on the bioengineering prospects of mammalian ribonucleic acid (RNA) is expected to result in significant biomedical advances. More specifically, the current trend focuses on devising non-coding (nc) RNAs as therapeutic candidates for complex neurological diseases. Given the pleiotropic and regulatory role, ncRNAs such as microRNAs and long non-coding RNAs are deemed as attractive therapeutic candidates. Currently, the list of non-coding RNAs in mammals is evolving, which presents the plethora of hidden possibilities including their scope in biomedicine. Herein, we critically review on the emerging repertoire of ncRNAs in neurological diseases such as Alzheimer’s disease, Parkinson’s disease, neuroinflammation and drug abuse disorders. Importantly, we present the advances in engineering of ncRNAs to improve their biocompatibility and therapeutic feasibility as well as provide key insights into the applications of bioengineered non-coding RNAs that are investigated for neurological diseases.

Evolving Landscape of Long Non-coding RNAs in Cerebrospinal Fluid: A Key Role From Diagnosis to Therapy in Brain Tumors

Long non-coding RNAs (lncRNAs) are a type of non-coding RNAs that act as molecular fingerprints and modulators of many pathophysiological processes, particularly in cancer. Specifically, lncRNAs can be involved in the pathogenesis and progression of brain tumors, affecting stemness/differentiation, replication, invasion, survival, DNA damage response, and chromatin dynamics. Furthermore, the aberrations in the expressions of these transcripts can promote treatment resistance, leading to tumor recurrence. The development of next-generation sequencing technologies and the creation of lncRNA-specific microarrays have boosted the study of lncRNA etiology. Cerebrospinal fluid (CSF) directly mirrors the biological fluid of biochemical processes in the brain. It can be enriched for small molecules, peptides, or proteins released by the neurons of the central nervous system (CNS) or immune cells. Therefore, strategies that identify and target CSF lncRNAs may be attractive as early diagnostic and therapeutic options. In this review, we have reviewed the studies on CSF lncRNAs in the context of brain tumor pathogenesis and progression and discuss their potential as biomarkers and therapeutic targets.

Alteration of long non-coding RNAs and mRNAs expression profiles by compound heterozygous ASXL3 mutations in the mouse brain

Compound mutations in the additional sex combs-like 3 (ASXL3) gene greatly impact the expression of long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs) in mouse myocardial tissues. Little is known about ASXL3 mutation effects on lncRNAs and mRNAs expression in the cerebrum and cerebellum. This study aims to clarify this point using quantitative real-time polymerase chain reaction and Western blotting. Transcriptome analysis based on RNA-seq followed by bioinformatics analysis were used to compare lncRNA and mRNA expression profiles. Cell proliferation, cell cycle progression, and apoptosis were evaluated after silencing of ASXL3 expression using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4- sulfophenyl)-2 H-tetrazolium method and flow cytometry. Results showed that ASXL3 gene expression was decreased in the cerebrum and cerebellum of mice with ASXL3 P723R*P1817A mutations. We identified 319 lncRNAs and 252 mRNAs differentially expressed in the cerebrum of ASXL3 P723R*P1817A mutant mice. In the cerebellum of ASXL3 P723R*P1817A mutant mice, 5330 lncRNAs and 2204 mRNAs were differentially expressed. Differentially expressed lncRNAs and mRNAs were widely distributed across the mouse genome and were associated with various biological processes and pathways. ASXL3 silencing by siRNA transfection affected the proliferation, cell cycle progression, and apoptosis of neural cells. Therefore, the ASXL3 P723R*P1817A mutations greatly modify the lncRNA and mRNA expression profiles in the mouse cerebrum and cerebellum.

The mechanism of non-coding RNAs in medulloblastoma

Medulloblastoma (MB) is one of the most common malignant tumors of the central nervous system in children. Although surgery, radiotherapy and chemotherapy have resulted in considerable progress in the treatment of this disease, the prognosis of patients with MB remains very poor. Therefore, highly specific molecular targeted treatment, which can improve the therapeutic efficacy and reduce the side effects of MB, has become a research hotspot. In recent years, non-coding RNAs (ncRNAs), which were initially considered to be transcriptional noise, have been shown to possess regulatory functions. A series of ncRNAs have been identified, including microRNAs and circular RNAs, which affect the expression of specific genes in a variety of tumors. These genes lead to the formation of a specific complex of proteins or they directly participate in protein synthesis in order to regulate the occurrence and development of tumors. The aim of the present review article was to summarize the recent research studies that have explored the ability of ncRNAs to regulate the occurrence and development of MB.

Long Non-Coding RNAs in Diagnosis, Treatment, Prognosis, and Progression of Glioma: A State-of-the-Art Review

Glioma is the most common malignant central nervous system tumor with significant mortality and morbidity. Despite considerable advances, the exact molecular pathways involved in tumor progression are not fully elucidated, and patients commonly face a poor prognosis. Long non-coding RNAs (lncRNAs) have recently drawn extra attention for their potential roles in different types of cancer as well as non-malignant diseases. More than 200 lncRNAs have been reported to be associated with glioma. We aimed to assess the roles of the most investigated lncRNAs in different stages of tumor progression and the mediating molecular pathways in addition to their clinical applications. lncRNAs are involved in different stages of tumor formation, invasion, and progression, including regulating the cell cycle, apoptosis, autophagy, epithelial-to-mesenchymal transition, tumor stemness, angiogenesis, the integrity of the blood-tumor-brain barrier, tumor metabolism, and immunological responses. The well-known oncogenic lncRNAs, which are upregulated in glioma, are H19, HOTAIR, PVT1, UCA1, XIST, CRNDE, FOXD2-AS1, ANRIL, HOXA11-AS, TP73-AS1, and DANCR. On the other hand, MEG3, GAS5, CCASC2, and TUSC7 are tumor suppressor lncRNAs, which are downregulated. While most studies reported oncogenic effects for MALAT1, TUG1, and NEAT1, there are some controversies regarding these lncRNAs. Expression levels of lncRNAs can be associated with tumor grade, survival, treatment response (chemotherapy drugs or radiotherapy), and overall prognosis. Moreover, circulatory levels of lncRNAs, such as MALAT1, H19, HOTAIR, NEAT1, TUG1, GAS5, LINK-A, and TUSC7, can provide non-invasive diagnostic and prognostic tools. Modulation of expression of lncRNAs using antisense oligonucleotides can lead to novel therapeutics. Notably, a profound understanding of the underlying molecular pathways involved in the function of lncRNAs is required to develop novel therapeutic targets. More investigations with large sample sizes and increased focus on in-vivo models are required to expand our understanding of the potential roles and application of lncRNAs in glioma.

Non-coding RNAs in Wilms' tumor: biological function, mechanism, and clinical implications

Non-coding RNAs are involved with maintenance and regulation of physiological mechanisms and are involved in pathological processes, such as cancer. Among the small ncRNAs, miRNAs are the most explored in tumorigenesis, metastasis development, and resistance to chemotherapy. These small molecules of ~ 22 nucleotides are modulated during early renal development, involved in the regulation of gene expression and Wilms' tumor progression. Wilms' tumors are embryonic tumors with few mutations and complex epigenetic dysregulation. In recent years, the small ncRNAs have been explored as potentially related both in physiological development and in the tumorigenesis of several types of cancer. Besides, genes regulated by miRNAs are related to biological pathways as PI3K, Wnt, TGF-β, and Hippo signaling pathways, among others, which may be involved with the underlying mechanisms of resistance to chemotherapy, and in this way, it has emerged as potential targets for cancer therapies, including for Wilms' tumors.

The Mechanistic Roles of ncRNAs in Promoting and Supporting Chemoresistance of Colorectal Cancer

Colorectal Cancer (CRC) is one of the most common gastrointestinal malignancies which has quite a high mortality rate. Despite the advances made in CRC treatment, effective therapy is still quite challenging, particularly due to resistance arising throughout the treatment regimen. Several studies have been carried out to identify CRC chemoresistance mechanisms, with research showing different signalling pathways, certain ATP binding cassette (ABC) transporters and epithelial mesenchymal transition (EMT), among others to be responsible for the failure of CRC chemotherapies. In the last decade, it has become increasingly evident that certain non-coding RNA (ncRNA) families are involved in chemoresistance. Research investigations have demonstrated that dysregulation of microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) contribute towards promoting resistance in CRC via different mechanisms. Considering the currently available data on this phenomenon, a better understanding of how these ncRNAs participate in chemoresistance can lead to suitable solutions to overcome this problem in CRC. This review will first focus on discussing the different mechanisms of CRC resistance identified so far. The focus will then shift onto the roles of miRNAs, lncRNAs and circRNAs in promoting 5-fluorouracil (5-FU), oxaliplatin (OXA), cisplatin and doxorubicin (DOX) resistance in CRC, specifically using ncRNAs which have been recently identified and validated under in vivo or in vitro conditions.

Novel insights into the interaction between long non-coding RNAs and microRNAs in glioma

Glioma is the most common brain tumor of the central nervous system. Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been identified to play a vital role in the initiation and progression of glioma, including tumor cell proliferation, survival, apoptosis, invasion, and therapy resistance. New documents emerged, which indicated that the interaction between long non-coding RNAs and miRNAs contributes to the tumorigenesis and pathogenesis of glioma. LncRNAs can act as competing for endogenous RNA (ceRNA), and molecular sponge/deregulator in regulating miRNAs. These interactions stimulate different molecular signaling pathways in glioma, including the lncRNAs/miRNAs/Wnt/β-catenin molecular signaling pathway, the lncRNAs/miRNAs/PI3K/AKT/mTOR molecular signaling pathway, the lncRNAs-miRNAs/MAPK kinase molecular signaling pathway, and the lncRNAs/miRNAs/NF-κB molecular signaling pathway. In this paper, the basic roles and molecular interactions of the lncRNAs and miRNAs pathway glioma were summarized to better understand the pathogenesis and tumorigenesis of glioma.