Long non-coding RNA MALAT1 promotes proliferation and suppresses apoptosis of glioma cells through derepressing Rap1B by sponging miR-101

Engineered smart materials for RNA based molecular therapy to treat Glioblastoma

Glioblastoma (GBM) is an aggressive malignancy of the central nervous system (CNS) that remains incurable despite the multitude of improvements in cancer therapeutics. The conventional chemo and radiotherapy post-surgery have only been able to improve the prognosis slightly; however, the development of resistance and/or tumor recurrence is almost inevitable. There is a pressing need for adjuvant molecular therapies that can successfully and efficiently block tumor progression. During the last few decades, non-coding RNAs (ncRNAs) have emerged as key players in regulating various hallmarks of cancer including that of GBM. The levels of many ncRNAs are dysregulated in cancer, and ectopic modulation of their levels by delivering antagonists or overexpression constructs could serve as an attractive option for cancer therapy. The therapeutic potential of several types of ncRNAs, including miRNAs, lncRNAs, and circRNAs, has been validated in both in vitro and in vivo models of GBM. However, the delivery of these RNA-based therapeutics is highly challenging, especially to the tumors of the brain as the blood-brain barrier (BBB) poses as a major obstacle, among others. Also, since RNA is extremely fragile in nature, careful considerations must be met while designing a delivery agent. In this review we have shed light on how ncRNA therapy can overcome the limitations of its predecessor conventional therapy with an emphasis on smart nanomaterials that can aide in the safe and targeted delivery of nucleic acids to treat GBM. Additionally, critical gaps that currently exist for successful transition from viral to non-viral vector delivery systems have been identified. Finally, we have provided a perspective on the future directions, potential pathways, and target areas for achieving rapid clinical translation of, RNA-based macromolecular therapy to advance the effective treatment of GBM and other related diseases.

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.

Novel sights on therapeutic, prognostic, and diagnostics aspects of non-coding RNAs in glioblastoma multiforme

Glioblastoma Multiforme (GBM) is the primary brain tumor and accounts for 200,000 deaths each year worldwide. The standard therapy includes surgical resection followed by temozolomide (TMZ)-based chemotherapy and radiotherapy. The survival period of GBM patients is only 12-15 months. Therefore, novel treatment modalities for GBM treatment are urgently needed. Mounting evidence reveals that non-coding RNAs (ncRNAs) were involved in regulating gene expression, the pathophysiology of GBM, and enhancing therapeutic outcomes. The combinatory use of ncRNAs, chemotherapeutic drugs, and tumor suppressor gene expression induction might provide an innovative, alternative therapeutic approach for managing GBM. Studies have highlighted the role of Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) in prognosis and diagnosis. Dysregulation of ncRNAs is observed in virtually all tumor types, including GBMs. Studies have also indicated the blood-brain barrier (BBB) as a crucial factor that hinders chemotherapy. Although several nanoparticle-mediated drug deliveries were degrading effectively against GBM in vitro conditions. However, the potential to cross the BBB and optimum delivery of oligonucleotide RNA into GBM cells in the brain is currently under intense clinical trials. Despite several advances in molecular pathogenesis, GBM remains resistant to chemo and radiotherapy. Targeted therapies have less clinical benefit due to high genetic heterogeneity and activation of alternative pathways. Thus, identifying GBM-specific prognostic pathways, essential genes, and genomic aberrations provide several potential benefits as subtypes of GBM. Also, these approaches will provide insights into new strategies to overcome the heterogenous nature of GBM, which will eventually lead to successful therapeutic interventions toward precision medicine and precision oncology.

Insights into the Role of LncRNAs and miRNAs in Glioma Progression and Their Potential as Novel Therapeutic Targets

Accumulating evidence supports that both long non-coding and micro RNAs (lncRNAs and miRNAs) are implicated in glioma tumorigenesis and progression. Poor outcome of gliomas has been linked to late-stage diagnosis and mostly ineffectiveness of conventional treatment due to low knowledge about the early stage of gliomas, which are not possible to observe with conventional diagnostic approaches. The past few years witnessed a revolutionary advance in biotechnology and neuroscience with the understanding of tumor-related molecules, including non-coding RNAs that are involved in the angiogenesis and progression of glioma cells and thus are used as prognostic biomarkers as well as novel therapeutic targets. The emerging research on lncRNAs and miRNAs highlights their crucial role in glioma progression, offering new insights into the disease. These non-coding RNAs hold significant potential as novel therapeutic targets, paving the way for innovative treatment approaches against glioma. This review encompasses a comprehensive discussion about the role of lncRNAs and miRNAs in gene regulation that is responsible for the promotion or the inhibition of glioma progression and collects the existing links between these key cancer-related molecules.

LncRNA AC040162.3 Promotes HCV-Induced T2DM Deterioration through the miRNA-223-3p/NLRP3 Molecular Axis

Background

Diabetes is one of the most common diseases and major public health burdens worldwide. Type 2 diabetes mellitus (T2DM) is associated with chronic hepatitis C virus (HCV) infection, and lncRNAs play an important role in HCV-induced T2DM. We aimed to explore the effect of lncRNA AC040162.3 on HCV-induced T2DM.

Methods

HCV was used to infect MIN6 cells to establish an in vitro model. HCV copy number and miRNA expression were detected by Real Time Quantitative PCR (RT-qPCR). Enzyme-Linked Immunosorbent Assay (ELISA) was used to detect the secretion of insulin, and methyl thiazolyl tetrazolium (MTT) was applied to analyze cell viability. Apoptosis was analyzed by Western blotting and flow cytometry. In addition, Western blotting and TdT-mediated dUTP Nick End Labeling (TUNEL) were used to analyze pyroptosis. Luciferase reporter assays were used to investigate the targeting relationship.

Results

The expression of LncRNA AC040162.3 and NLRP3 was markedly increased in HCV-T2DM, while the expression of miR-223-3p was remarkably inhibited. In vitro experiments demonstrated that lncRNA AC040162.3 silencing or miR-223-3p overexpression remarkably alleviated HCV-induced T2DM deterioration by inhibiting cell apoptosis and pyroptosis and enhancing cell viability. We then demonstrated that silencing lncRNA AC040162.3 promoted the expression of miR-223-3p and that miR-223-3p bound to lncRNA AC040162.3 and the NLRP3 binding site. In addition, the protective effects of LncRNA AC040162.3 silencing in HCV-infected MIN6 cells were reversed by overexpression of NLRP3 or silencing of miR-223-3p.

Conclusion

Silencing of lncRNA AC040162.3 alleviates the process of HCV-induced T2DM by governing the miR-223-3p/NLRP3 axis.

Comparison of Oncogenes, Tumor Suppressors, and MicroRNAs Between Schizophrenia and Glioma: The Balance of Power

The risk of cancer in schizophrenia has been controversial. Confounders of the issue are cigarette smoking in schizophrenia, and antiproliferative effects of antipsychotic medications. The author has previously suggested comparison of a specific cancer like glioma to schizophrenia might help determine a more accurate relationship between cancer and schizophrenia. To accomplish this goal, the author performed three comparisons of data; the first a comparison of conventional tumor suppressors and oncogenes between schizophrenia and cancer including glioma. This comparison determined schizophrenia has both tumor-suppressive and tumor-promoting characteristics. A second, larger comparison between brain-expressed microRNAs in schizophrenia with their expression in glioma was then performed. This identified a core carcinogenic group of miRNAs in schizophrenia offset by a larger group of tumor-suppressive miRNAs. This proposed "balance of power" between oncogenes and tumor suppressors could cause neuroinflammation. This was assessed by a third comparison between schizophrenia, glioma and inflammation in asbestos-related lung cancer and mesothelioma (ALRCM). This revealed that schizophrenia shares more oncogenic similarity to ALRCM than glioma.

Alternative RNA splicing modulates ribosomal composition and determines the spatial phenotype of glioblastoma cells

Glioblastoma (GBM) is characterized by exceptionally high intratumoral heterogeneity. However, the molecular mechanisms underlying the origin of different GBM cell populations remain unclear. Here, we found that the compositions of ribosomes of GBM cells in the tumour core and edge differ due to alternative RNA splicing. The acidic pH in the core switches before messenger RNA splicing of the ribosomal gene RPL22L1 towards the RPL22L1b isoform. This allows cells to survive acidosis, increases stemness and correlates with worse patient outcome. Mechanistically, RPL22L1b promotes RNA splicing by interacting with lncMALAT1 in the nucleus and inducing its degradation. Contrarily, in the tumour edge region, RPL22L1a interacts with ribosomes in the cytoplasm and upregulates the translation of multiple messenger RNAs including TP53. We found that the RPL22L1 isoform switch is regulated by SRSF4 and identified a compound that inhibits this process and decreases tumour growth. These findings demonstrate how distinct GBM cell populations arise during tumour growth. Targeting this mechanism may decrease GBM heterogeneity and facilitate therapy.

Malat1 deficiency prevents hypoxia-induced lung dysfunction by protecting the access to alveoli

Hypoxia is common in lung diseases and a potent stimulator of the long non-coding RNA Metastasis-Associated Lung Adenocarcinoma Transcript 1 (MALAT1). Herein, we investigated the impact of Malat1 on hypoxia-induced lung dysfunction in mice. Malat1-deficient mice and their wild-type littermates were tested after 8 days of normoxia or hypoxia (10% oxygen). Hypoxia decreased elastance of the lung by increasing lung volume and caused in vivo hyperresponsiveness to methacholine without altering the contraction of airway smooth muscle. Malat1 deficiency also modestly decreased lung elastance but only when tested at low lung volumes and without altering lung volume and airway smooth muscle contraction. The in vivo responsiveness to methacholine was also attenuated by Malat1 deficiency, at least when elastance, a readout sensitive to small airway closure, was used to assess the response. More impressively, in vivo hyperresponsiveness to methacholine caused by hypoxia was virtually absent in Malat1-deficient mice, especially when hysteresivity, a readout sensitive to small airway narrowing heterogeneity, was used to assess the response. Malat1 deficiency also increased the coefficient of oxygen extraction and decreased ventilation in conscious mice, suggesting improvements in gas exchange and in clinical signs of respiratory distress during natural breathing. Combined with a lower elastance at low lung volumes at baseline, as well as a decreased propensity for small airway closure and narrowing heterogeneity during a methacholine challenge, these findings represent compelling evidence suggesting that the lack of Malat1 protects the access to alveoli for air entering the lung.

The functions of long noncoding RNAs on regulation of F-box proteins in tumorigenesis and progression

Accumulated evidence has revealed that F-box protein, a subunit of SCF E3 ubiquitin ligase complexes, participates in carcinogenesis and tumor progression via targeting its substrates for ubiquitination and degradation. F-box proteins could be regulated by cellular signaling pathways and noncoding RNAs in tumorigenesis. Long noncoding RNA (lncRNA), one type of noncoding RNAs, has been identified to modulate the expression of F-box proteins and contribute to oncogenesis. In this review, we summarize the role and mechanisms of multiple lncRNAs in regulating F-box proteins in tumorigenesis, including lncRNAs SLC7A11-AS1, MT1JP, TUG1, FER1L4, TTN-AS1, CASC2, MALAT1, TINCR, PCGEM1, linc01436, linc00494, GATA6-AS1, and ODIR1. Moreover, we discuss that targeting these lncRNAs could be helpful for treating cancer via modulating F-box protein expression. We hope our review can stimulate the research on exploration of molecular insight into how F-box proteins are governed in carcinogenesis. Therefore, modulation of lncRNAs is a potential therapeutic strategy for cancer therapy via regulation of F-box proteins.

Exosomes Derived from Tumor Cells Initiate Breast Cancer Cell Metastasis and Chemoresistance through a MALAT1-Dependent Mechanism

Background. Chemoresistance poses a great hindrance in the treatment of breast cancer (BC). Interestingly, exosome (Exo)-mediated transfer of long noncoding RNAs (lncRNAs) has been reported to regulate chemoresistance in diverse diseases. We herein investigate the potential role of lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) transferred by BC cell-derived Exo in chemoresistance of BC cells. Methods. BC-related lncRNAs were identified. Exosomes were isolated and verified from BC cells. The expression patterns of MALAT1 were then examined in the adriamycin (ADR)-sensitive and resistant cells and the isolated Exo, followed by the analysis of the downstream microRNA (miRNA) of MALAT1. The role and mechanism of MALAT1 transmitted by BC cell-derived Exo in BC cell metastasis and chemoresistance were assessed. Results. MALAT1 was highly expressed in BC cells and their Exo. In addition, MALAT1 delivered by BC cell-derived Exo augmented the malignant properties and chemoresistance of BC cells. Mechanistically, MALAT1 bound to miR-1-3p and limited the miR-1-3p expression, which sequentially targeted the vasodilator-stimulated phosphoprotein (VASP) protein. Moreover, silencing of VASP inhibited the activation of the RAP1 member of RAS oncogene family (Rap1) signaling pathway, which led to the attenuation of BC cell malignant properties and chemoresistance. In vivo assay further validated the tumor-promoting effect of Exo-MALAT1 via regulation of the miR-1-3p/VASP/Rap1 axis. Conclusion. Collectively, MALAT1 loaded by BC cell-derived Exo can accelerate BC cell metastasis and chemoresistance via disruption of miR-1-3p-mediated inhibition of the VASP/Rap1 signaling axis.

Long Non-coding RNA and mRNA Co-expression Network Reveals Novel Players in Pleomorphic Xanthoastrocytoma

Histological interpretation of the rare pleomorphic xanthoastrocytoma (PXA) has been the holy grail for treatment options. However, no stand-alone clinical interventions have been developed owing to the lack of gene expression profiling data in PXA/APXA patients. We first time report the comprehensive analyses of the coding as well as long non-coding RNA (lncRNA) signatures of PXA/APXA patients. Several genes such as IGFBP2, NF1, FOS, ERBB2, and lncRNAs such as NEAT1, HOTAIRM1, and GAS5 known to play crucial roles in glioma patients were also deregulated in PXA patients suggesting the commonality in the molecular signatures. PPI network, co-expression, and lncRNA-mRNA interaction studies unraveled hub genes (such as ERBB2, FOS, RPA1) and networks that may play a critical role in PXA biology. The most enriched pathways based on gene profiles were related to TLR, chemokine, MAPK, Rb, and PI3K-Akt signaling pathways. The lncRNA targets were enriched in glucuronidation, adipogenesis, TGF-beta signaling, EGF/EGFR signaling, and cell cycle pathways. Interestingly, several mRNAs like PARVG, and ABI2 were found to be targeted by multiple lncRNAs suggesting a tight control of their levels. Some of the most prominent lncRNA-mRNA pairs were LOC728730: MRPL9, XLOC_l2_011987: ASIC2, lnc-C1QTNF5-1: RNF26. Notably, several lncRNAs such as lnc-CETP-1, lnc-XRCC3-1, lnc-RPL31-1, lnc-USP13-1, and MAPKAPK5-AS1, and genes such as RPA1, NTRK3, and CNRP1 showed strong correlation to the progression-free survival of PXA patients suggesting their potential as novel biomarkers. Overall, the findings of this study may facilitate the development of a new realm of RNA biology in PXA that may have clinical significance in the future.

LINC02381-ceRNA exerts its oncogenic effect through regulation of IGF1R signaling pathway in glioma

PURPOSE

LncRNAs play essential roles in the cellular and molecular biology of glioma. Some LncRNAs exert their role through sponging miRNAs and regulating multiple signaling pathways. LINC02381 is involved in several cancer types as either oncogene or tumor suppressor. Here, we intended to find the molecular mechanisms of the LINC02381 effect during the glioma progression in related cell lines.

METHODS AND RESULTS

RNA-seq data analysis indicated the oncogenic characteristics of LINC02381, and RT-qPCR results confirmed its upregulation compared to normal tissues. Besides its expression was relatively stronger in invasive glioma cell lines. Furthermore, in silico analysis revealed LINC02381 is concentrated in the cytoplasm and predicted its sponging effect against miR-128 and miR-150, which was verified through dual luciferase assay. When LINC02381 was overexpressed in 1321N1, U87, and A172 cell lines, IGF1R and TrkC receptors as well as their downstream pathways (PI3K and RAS/MAPK), were upregulated, detected by RT-qPCR, and verified by western analysis. Consistently, LINC02381 overexpression was followed by an increased proliferation rate of transfected glioma cell lines, detected by flow cytometry and MTT assay, and RT-qPCR. It also resulted in elevated EMT and stemness markers expression level, increased migration rate, and reduced apoptosis rate, detected by RT-qPCR, western analysis, scratch test, and Annexin/PI flow cytometry analysis, respectively.

CONCLUSION

The overall results indicated that LINC02381 exerts its oncogenic effect in glioma cells through sponging miR-128 and miR-150 to upregulate the IGF1R signaling pathway. Our results introduce LINC02381 and miR-128, and miR-150 as potential prognosis and therapy targets for the treatment of glioma.

Non-coding RNAs and glioblastoma: Insight into their roles in metastasis

Glioma, also known as glioblastoma multiforme (GBM), is the most prevalent and most lethal primary brain tumor in adults. Gliomas are highly invasive tumors with the highest death rate among all primary brain malignancies. Metastasis occurs as the tumor cells spread from the site of origin to another site in the brain. Metastasis is a multifactorial process, which depends on alterations in metabolism, genetic mutations, and the cancer microenvironment. During recent years, the scientific study of non-coding RNAs (ncRNAs) has led to new insight into the molecular mechanisms involved in glioma. Many studies have reported that ncRNAs play major roles in many biological procedures connected with the development and progression of glioma. Long ncRNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs) are all types of ncRNAs, which are commonly dysregulated in GBM. Dysregulation of ncRNAs can facilitate the invasion and metastasis of glioma. The present review highlights some ncRNAs that have been associated with metastasis in GBM. miRNAs, circRNAs, and lncRNAs are discussed in detail with respect to their relevant signaling pathways involved in metastasis.

Prognostic and immunological significance of metastasis associated lung adenocarcinoma transcript 1 among different kinds of cancers

LncRNAs belong to the type of noncoding RNA transcripts, which exceed 200 nucleotides in size. MALAT1 as one of the earlier identified lncRNAs in cancer is investigated by more and more scientific researchers. Expression, clinical significance and function of MALAT1 in pan-cancer exist as big difference. To detect the expression and clinical significance of MALAT1 gene precisely and comprehensively among different kinds of cancers, some classical databases such as GEPIA, TIMER, KM Plotter, and PrognoScan were fully applied. An immunological role of MALAT1 among different kinds of cancers was also determined in TIMER database. Our results showed that MALAT1 was differently expressed in different kinds of cancers using GEPIA, Oncomine, and TIMER databases to analyze. Especially, MALAT1 high RNA level was related to the early stage in lung and gastric cancer patients. MALAT1 expression was closely related to prognosis among different cancer patients. Furthermore, expression of MALAT1 was related to tumor immune cell infiltrating. Expression level of MALAT1 was also related to immune makers such as macrophage, T cell, NK cells, and so on. These findings indicate that MALAT1 could be a potential prognostic biomarker of some kinds of cancer and was significantly correlated with tumor-infiltrating immune cells in a wide variety of cancers.

lncRNA MALAT1/miR‑26a/26b/ST8SIA4 axis mediates cell invasion and migration in breast cancer cell lines

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a long non-coding RNA that is overexpressed in various human cancers, including breast cancer. Evidence has associated the function of the α-2,8-sialyltransferase (ST8SIA) family with breast cancer. The present study aimed to investigate the potential roles of MALAT1 in breast cancer development and progression using analyses of both breast cancer tissues and cell lines. The mRNA levels of MALAT1, microRNA (miR)-26a/26b and ST8SIA4 were detected by reverse transcription-quantitative PCR (RT-qPCR) and the protein level of ST8SIA4 was assessed by western blot analysis. Cell proliferation, invasion and migration were detected by CCK-8, wound healing and Transwell assays, respectively. Interactions between MALAT1 and miR-26a/26b were assessed using fluorescence in situ hybridization, RNA immunoprecipitation and luciferase reporter assays. Herein, different levels of MALAT1 were primarily observed in human breast cancer samples and cells. Upregulated MALAT1 was a crucial predictor of poor breast cancer prognosis. Altered MALAT1 modulated cell progression in breast cancer. Moreover, miR-26a/26b was confirmed as a direct regulator of MALAT1, and ST8SIA4 was predicted as a target of miR-26a/26b. Functional analysis in human breast cancer cell lines demonstrated that MALAT1 modulated breast cancer cell tumorigenicity by acting as a competing endogenous lncRNA (ceRNA) to regulate ST8SIA4 levels by sponging miR-26a/26b. The identification of the MALAT1/miR-26a/26b/ST8SIA4 axis which contributes to breast cancer progression may constitute a potential new therapeutic target.

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.

Long non-coding RNAs in brain tumors: roles and potential as therapeutic targets

Brain tumors are associated with adverse outcomes despite improvements in radiation therapy, chemotherapy, and photodynamic therapy. However, treatment approaches are evolving, and new biological phenomena are being explored to identify the appropriate treatment of brain tumors. Long non-coding RNAs (lncRNAs), a type of non-coding RNA longer than 200 nucleotides, regulate gene expression at the transcriptional, post-transcriptional, and epigenetic levels and are involved in a variety of biological functions. Recent studies on lncRNAs have revealed their aberrant expression in various cancers, with distinct expression patterns associated with their instrumental roles in cancer. Abnormal expression of lncRNAs has also been identified in brain tumors. Here, we review the potential roles of lncRNAs and their biological functions in the context of brain tumors. We also summarize the current understanding of the molecular mechanisms and signaling pathways related to lncRNAs that may guide clinical trials for brain tumor therapy.

Competing Endogenous RNA Networks in Glioma

Gliomas are the most common and malignant primary brain tumors. Various hallmarks of glioma, including sustained proliferation, migration, invasion, heterogeneity, radio- and chemo-resistance, contribute to the dismal prognosis of patients with high-grade glioma. Dysregulation of cancer driver genes is a leading cause for these glioma hallmarks. In recent years, a new mechanism of post-transcriptional gene regulation was proposed, i.e., "competing endogenous RNA (ceRNA)." Long non-coding RNAs, circular RNAs, and transcribed pseudogenes act as ceRNAs to regulate the expression of related genes by sponging the shared microRNAs. Moreover, coding RNA can also exert a regulatory role, independent of its protein coding function, through the ceRNA mechanism. In the latest glioma research, various studies have reported that dysregulation of certain ceRNA regulatory networks (ceRNETs) accounts for the abnormal expression of cancer driver genes and the establishment of glioma hallmarks. These achievements open up new avenues to better understand the hidden aspects of gliomas and provide new biomarkers and potential efficient targets for glioma treatment. In this review, we summarize the existing knowledge about the concept and logic of ceRNET and highlight the emerging roles of some recently found ceRNETs in glioma progression.

LINC00174 is a favorable prognostic biomarker in glioblastoma via promoting proliferative phenotype

OBJECTIVE

To investigate the expression pattern, prognostic value and biological functional of LINC00174 in glioma.

METHODS

In total, 140 glioma samples were collected as discovery cohort. TCGA RNA sequence dataset was obtained as validation set. Kaplan-Meier survival and multivariate Cox analysis were performed to evaluate survival difference. Furthermore, the biological function of LINC00174 was analyzed by clonogenic and intracranial tumor model assays.

RESULTS

Overexpressed LINC00174 was significantly correlated with tumor grade as well as the higher mortality in survival analysis both in the discovery and the validation GBM cohorts. Besides, LINC00174 served as an independent prognostic indicator in glioblastoma patients. Additionally, knock down of LINC00174 expression significantly suppressed GBM cells' proliferation both in vitro and vivo.

CONCLUSION

LINC00174 acts as an oncogene in glioma and may be a new potential therapeutic target.

Lnc GNG12-AS1 knockdown suppresses glioma progression through the AKT/GSK-3β/β-catenin pathway

BACKGROUND

Long non-coding RNAs (lncRNAs) are increasingly being regarded as regulators of glioma development. Notably, some studies report that GNG12-AS1 plays important functions and molecular mechanism in breast cancer, but there are no existing studies in glioma.

OBJECTIVE

To analyze the biological functions and potential mechanisms of GNG12-AS1 in glioma.

METHODS

We detected the expression of GNG12-AS1 in glioma tissues through analyzing TCGA data as well as our clinical samples. We then evaluated cell proliferation through MTT assay and colony formation and cell migration by transwell assay, wound healing assay and single cell tracking assay. After, we analyzed the effects of the AKT/GSK-3β/β-catenin through Western blotting and utilized the β-catenin agonist SKL2001 for the rescue experiment.

RESULTS

GNG12-AS1 was highly expressed in glioma tissues. The silence of GNG12-AS1 inhibited the proliferation, migration and epithelial-mesenchymal transition of glioma cells, and reduced the activity of the AKT/GSK-3β/β-catenin pathway. Notably, SKL2001 could reverse cell migration as well as β-catenin expression in glioma cells with lower GNG12-AS1 expression.

CONCLUSIONS

GNG12-AS1 regulates proliferation and migration of glioma cells through the AKT/GSK-3β/β-catenin signaling and can perhaps be a new target for the treatment of glioma.

Non-Syndromic Intellectual Disability and Its Pathways: A Long Noncoding RNA Perspective

Non-syndromic intellectual disability (NS-ID or idiopathic) is a complex neurodevelopmental disorder that represents a global health issue. Although many efforts have been made to characterize it and distinguish it from syndromic intellectual disability (S-ID), the highly heterogeneous aspect of this disorder makes it difficult to understand its etiology. Long noncoding RNAs (lncRNAs) comprise a large group of transcripts that can act through various mechanisms and be involved in important neurodevelopmental processes. In this sense, comprehending the roles they play in this intricate context is a valuable way of getting new insights about how NS-ID can arise and develop. In this review, we attempt to bring together knowledge available in the literature about lncRNAs involved with molecular and cellular pathways already described in intellectual disability and neural function, to better understand their relevance in NS-ID and the regulatory complexity of this disorder.

Potential of long non-coding RNAs as a therapeutic target and molecular markers in glioblastoma pathogenesis

Glioblastoma (GB) is by far the most hostile type of malignant tumor that primarily affects the brain and spine, derived from star-shaped glial cells that are astrocytes and oligodendrocytes. Despite of significant efforts in recent years in glioblastoma research, the clinical efficacy of existing medical intervention is still limited and very few potential diagnostic markers are available. Long non-coding RNAs (lncRNAs) that lacks protein-coding capabilities were previously thought to be "junk sequences" in mammalian genomes are quite indispensible epigenetic regulators that can positively or negatively regulate gene expression and nuclear architecture, with significant roles in the initiation and development of tumors. Nevertheless, the precise mechanism of these distortedly expressed lncRNAs in glioblastoma pathogenesis is not yet fully understood. Since the advent of high-throughput sequencing technologies, more and more research have elucidated that lncRNAs are one of the most promising prognostic biomarkers and therapeutic targets for glioblastoma. In this paper, I briefly outlined the existing findings of lncRNAs. And also summarizes the profiles of different lncRNAs that have been broadly classified in glioblastoma research, with emphasis on both their prognostic and therapeutic values.

Long Non-coding RNA MALAT1 Upregulates ZEB2 Expression to Promote Malignant Progression of Glioma by Attenuating miR-124

Long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been shown to play a critical role in the development of several malignancies. However, the potential molecular mechanism of MALAT1 in glioma remains unclear. In the present study, we found that the expression of MALAT1 was aberrantly increased in both human glioma tissues and cells and associated with poor prognosis in glioma patients. We further found that MALAT1 silencing significantly inhibited glioma cell proliferation while induced cell cycle arrest and apoptosis. In parallel, knockdown of MALAT1 decreased tumor volume in vivo. These results suggested that MALAT1 acts as a functional oncogene, resulting in the oncogenicity in glioma. Nevertheless, the tumor-suppressive effect of MALAT1 silencing was reversed by miR-124. Besides, the relevance of ZEB2 in tumor progression has been studied in several forms of human cancer, and ZEB2 was identified as a target of miR-124 and negatively regulated by miR-124. MALAT1 overexpression or miR-124 inhibitor led to increased expression of ZEB2. In summary, our study depicts a novel pathway of MALAT1/miR-124/ZEB2 that regulates the progression of glioma and might provide a promising strategy for glioma therapy.

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.

Long non-coding RNAs as the regulators and targets of macrophage M2 polarization

Macrophages are immune cells with high heterogeneity and plasticity. M2 polarization is one extreme of the well-established phenotypes of macrophage polarization, and involves in diverse biological processes. The polarization process is initiated at the command of numerous components. Long non-coding RNAs (lncRNAs) are RNAs longer than 200 nucleotides with limited protein-coding capacity. Recent studies have revealed a newly found subset of lncRNAs engaged in the M2 polarization and their potent and multifunctional roles in developing diseases. By interfering with specific signaling pathways and altering the active mode, acting as the sponges of microRNAs or decoys of transcription factors, lncRNAs prompted macrophages to an M2 phenotype. Further, lncRNAs can bind to the genome to regulate the chromatin dynamics or work as a platform for protein complexes tether. Exosomal lncRNAs can also orchestrate the polarization in a paracrine way. To make it easier to interpret the roles of lncRNAs in the M2 polarization, we review the reported lncRNAs according to the underlying mechanisms. Moreover, we discuss the possibilities of targeting macrophages' M2 polarization using the oligonucleotides drugs or clustered regularly interspaced palindromic repeats (CRISPR) technologies to provoke wisdom on the therapeutic strategies.

Bioinformatics Analysis of Differentially Expressed Genes and miRNAs in Low-Grade Gliomas

Low-grade glioma is the most common type of primary intracranial tumor. In the last 3 years, new observations of molecular precursors in adults with gliomas have led to a modification in the histopathologic classification of these brain tumors. Among the biomarkers that have been highlighted, we have the micro RNAs (miRNAs) which play a crucial role in the regulation of gene expression and the long noncoding RNAs (lncRNAs) controlling various cellular and metabolic pathways. In our study, large-scale data on sequenced RNA and miRNAs from 516 patients were obtained from the Cancer Genome Atlas database by the TCGAbiolinks package. We identified the differential expression of miRNAs and genes using the Limma package and then we used the ClusterProfiler package for annotations of the biological pathways of the expressed genes, the survival package to estimate the survival analysis, and the GDCRNATools package to determine miRNAs-genes and miRNAs-lncRNAs interactions. We obtained a significant correlation between the miRNAs identified and the overall survival of the patients (log-rank P < .05) and we have theoretically proposed a novel network of miRNAs involved in low-grade gliomas, specifically astrocytomas and oligodendrogliomas, which combine both genes and lncRNAs.

Regulatory Networks of LncRNA MALAT-1 in Cancer

Long noncoding (lnc)RNAs are a group of RNAs with a length greater than 200 nt that do not encode a protein but play an essential role in regulating the expression of target genes in normal biological contexts as well as pathologic processes including tumorigenesis. The lncRNA metastasis-associated lung adenocarcinoma transcript (MALAT)-1 has been widely studied in cancer. In this review, we describe the known functions of MALAT-1; its mechanisms of action; and associated signaling pathways and their clinical significance in different cancers. In most malignancies, including lung, colorectal, thyroid, and other cancers, MALAT-1 functions as an oncogene and is upregulated in tumors and tumor cell lines. MALAT-1 has a distinct mechanism of action in each cancer type and is thus at the center of large gene regulatory networks. Dysregulation of MALAT-1 affects cellular processes such as alternative splicing, epithelial–mesenchymal transition, apoptosis, and autophagy, which ultimately results in the abnormal cell proliferation, invasion, and migration that characterize cancers. In other malignancies, such as glioma and endometrial carcinoma, MALAT-1 functions as a tumor suppressor and thus forms additional regulatory networks. The current evidence indicates that MALAT-1 and its associated signaling pathways can serve as diagnostic or prognostic biomarker or therapeutic target in the treatment of many cancers.

Long non-coding RNAs as epigenetic mediator and predictor of glioma progression, invasiveness, and prognosis

Gliomas are aggressive brain tumors with high mortality rate. Over the past several years, non-coding RNAs, specifically the long non-coding RNAs (lncRNAs), have emerged as biomarkers of considerable interest. Emerging data reveals distinct patterns of expressions of several lncRNAs in the glioma tissues, relative to their expression in normal brains. This has led to the speculation for putative exploitation of lncRNAs as diagnostic biomarkers as well as biomarkers for targeted therapy. With a focus on lncRNAs that have shown promise as epigenetic biomarkers in the proliferation, migration, invasion, angiogenesis and metastasis in various glioma models, we discuss several such lncRNAs. The data from cell line / animal model-based studies as well as analysis from human patient samples is presented for the most up-to-date information on the topic. Overall, the information provided herein makes a compelling case for further evaluation of lncRNAs in clinical settings.

Targeting BC200/miR218-5p Signaling Axis for Overcoming Temozolomide Resistance and Suppressing Glioma Stemness

Background: Glioblastoma (GB) is one of the most common (~30%) and lethal cancers of the central nervous system. Although new therapies are emerging, chemoresistance to treatment is one of the major challenges in cancer treatment. Brain cytoplasmic 200 (BC200) RNA, also known as BCYRN1, is a long noncoding RNA (lncRNA) that has recently emerged as one of the crucial members of the lncRNA family. BC200 atypical expression is observed in many human cancers. BC200 expression is higher in invasive cancers than in benign tumors. However, the clinical significance of BC200 and its effect on GB multiforme is still unexplored and remains unclear. Methods: BC200 expression in GB patients and cell lines were investigated through RT-qPCR, immunoblotting, and immunohistochemistry analysis. The biological importance of BC200 was investigated in vitro and in vivo through knockdown and overexpression. Bioinformatic analysis was performed to determine miRNAs associated with BC200 RNA. Results: Our findings revealed that in GB patients, BC200 RNA expression was higher in blood and tumor tissues than in normal tissues. BC200 RNA expression have a statistically significant difference between the IDH1 and P53 status. Moreover, the BC200 RNA expression was higher than both p53, a prognostic marker of glioma, and Ki-67, a reliable indicator of tumor cell proliferation activity. Overexpression and silencing of BC200 RNA both in vitro and in vivo significantly modulated the proliferation, self-renewal, pluripotency, and temozolomide (TMZ) chemo-resistance of GB cells. It was found that the expressions of BC200 were up-regulated and that of miR-218-5p were down-regulated in GB tissues and cells. miR-218-5p inhibited the expression of BC200. Conclusions: This study is the first to show that the molecular mechanism of BC200 promotes GB oncogenicity and TMZ resistance through miR-218-5p expression modulation. Thus, the noncoding RNA BC200/miR-218-5p signaling circuit is a potential clinical biomarker or therapeutic target for GB.

Coding of Glioblastoma Progression and Therapy Resistance through Long Noncoding RNAs

Glioblastoma is the most aggressive and lethal primary brain malignancy, with an average patient survival from diagnosis of 14 months. Glioblastoma also usually progresses as a more invasive phenotype after initial treatment. A major step forward in our understanding of the nature of glioblastoma was achieved with large-scale expression analysis. However, due to genomic complexity and heterogeneity, transcriptomics alone is not enough to define the glioblastoma “fingerprint”, so epigenetic mechanisms are being examined, including the noncoding genome. On the basis of their tissue specificity, long noncoding RNAs (lncRNAs) are being explored as new diagnostic and therapeutic targets. In addition, growing evidence indicates that lncRNAs have various roles in resistance to glioblastoma therapies (e.g., MALAT1, H19) and in glioblastoma progression (e.g., CRNDE, HOTAIRM1, ASLNC22381, ASLNC20819). Investigations have also focused on the prognostic value of lncRNAs, as well as the definition of the molecular signatures of glioma, to provide more precise tumor classification. This review discusses the potential that lncRNAs hold for the development of novel diagnostic and, hopefully, therapeutic targets that can contribute to prolonged survival and improved quality of life for patients with glioblastoma.

MicroRNA-101 suppresses colorectal cancer progression by negative regulation of Rap1b

Colorectal cancer (CRC) is the fourth most lethal malignancy and is the second most common cause of cancer-associated mortality worldwide. The development of high-throughput sequencing has enabled the identification of potential biomarkers for the diagnosis and treatment of various types of cancer. Although microRNA-101 (miR-101) has been demonstrated to be a potential biomarker of CRC, its detailed mechanisms remain to be fully discovered. In the present study, overall survival analysis was applied to determine the association between miR-101 and CRC prognosis. Reverse transcription-quantitative PCR (RT-qPCR) was used to examine gene expression levels in tissues and cells. Cell proliferative and apoptotic activities were determined by MTT and flow cytometry assays, respectively. Wound healing and Transwell assays were used to examine CRC cell migration and invasion, respectively. In the present study, RT-qPCR analysis indicated that miR-101 was significantly downregulated in CRC tissues and cells. However, clinical data collected from The Cancer Genome Atlas revealed no significant association between the expression levels of miR-101 and the prognosis of CRC. Additionally, miR-101 inhibited the progression of CRC by directly binding to the 3′-untranslated region of Ras-related protein Rap1b (Rap1b). This was associated with downregulation of Rap1b expression. Furthermore, the overexpression of Rap1b promoted miR-101 mimic-attenuated CRC cell progression. The present study demonstrated that miR-101 may be involved in the repression of the CRC progression by forming a negative feedback loop with Rap1b. The findings revealed the interaction between miR-101 and Rap1b during the progression of CRC, which could aid the development of therapeutic strategies.

Long Non-coding RNA MALAT1/microRNA-143/VEGFA Signal Axis Modulates Vascular Endothelial Injury-Induced Intracranial Aneurysm

The roles of some long non-coding RNAs (lncRNAs) in intracranial aneurysm (IA) have been investigated in many studies. The aim of this study is to elucidate the mechanism of lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1)/microRNA-143 (miR-143)/vascular endothelial growth factor-A (VEGFA) signal axis in vascular endothelial injury-induced IA. MALAT1, miR-143, and VEGFA expression in IA tissues and normal arterial tissues were detected. Matrix metalloproteinase 9 (MMP-9) in tissues, von Willebrand factor (vWF) in serum and tissues, and endothelin-1 (ET-1) in serum were detected. The modeled IA rats were injected with silenced or overexpressed MALAT1 for detecting vascular endothelial injury. Vascular endothelial cells from patients with IA were abstracted and transfected with silenced or overexpressed MALAT1 to verify the impacts of MALAT1 on cell viability and apoptosis. The connections among MALAT1, miR-143, and VEGFA were verified by online prediction, luciferase activity, and RNA-pull down assays. Overexpression of MALAT1 and VEGFA and poor expression of miR-143 were found in IA tissues. Downregulation of MALAT1 inhibited blood pressure, the expression of ET-1, vWF, and MMP-9, as well as the apoptotic index of vascular endothelial cells of rats with IA. Downregulated MALAT1 inhibited apoptosis and promoted viability of vascular endothelial cells in IA. MALAT1 bound to miR-143 and miR-143 targeted VEGFA. This study suggests that MALAT1 elevates VEGFA expression through competitive binding to miR-143, thereby boosting apoptosis and attenuating viability of vascular endothelial cells in IA.

lncRNA NR2F1-AS1 promotes breast cancer angiogenesis through activating IGF-1/IGF-1R/ERK pathway

Long non‐coding RNAs (lncRNAs) take various effects in cancer mostly through sponging with microRNAs (miRNAs). lncRNA NR2F1‐AS1 is found to promote tumour progression in hepatocellular carcinoma, endometrial cancer and thyroid cancer. However, the role of lncRNA NR2F1‐AS1 in breast cancer angiogenesis remains unknown. In this study, we found lncRNA NR2F1‐AS1 was positively related with CD31 and CD34 in breast cancer through Pearson's correlation analysis, while lncRNA NR2F1‐AS1 transfection promoted human umbilical vascular endothelial cell (HUVEC) tube formation. In breast cancer cells, lncRNA NR2F1‐AS1 enhanced the HUVEC proliferation, tube formation and migration ability through tumour‐conditioned medium (TCM). In zebrafish model, lncRNA NR2F1‐AS1 increased the breast cancer cell‐related neo‐vasculature and subsequently promoted the breast cancer cell metastasis. In mouse model, lncRNA NR2F1‐AS1 promoted the tumour vessel formation, increased the micro vessel density (MVD) and then induced the growth of primary tumour. Mechanically, lncRNA NR2F1‐AS1 increased insulin‐like growth factor‐1 (IGF‐1) expression through sponging miRNA‐338‐3p in breast cancer cells and then activated the receptor of IGF‐1 (IGF‐1R) and extracellular signal‐regulated kinase (ERK) pathway in HUVECs. These results indicated that lncRNA NR2F1‐AS1 could promote breast cancer angiogenesis through IGF‐1/IGF‐1R/ERK pathway.

Current advances of long non-coding RNAs mediated by wnt signaling in glioma

Glioma is the most common and aggressive brain tumor in the central nervous system (CNS), in which Wnt signaling pathway has been verified to play a pivotal role in regulating the initiation and progression. Currently, numerous studies have indicated that long non-coding RNAs (lncRNAs) have critical functions across biological processes including cell proliferation, colony formation, migration, invasion and apoptosis via Wnt signaling pathway in glioma. This review depicts canonical and non-canonical Wnt/β-catenin signaling pathway properties and relative processing mechanisms in gliomas, and summarizes the function and regulation of lncRNAs mediated by Wnt signaling pathway in the development and progression of glioma. Ultimately, we hope to seek out promising biomarkers and reliable therapeutic targets for glioma.

Blocking the LncRNA MALAT1/miR-224-5p/NLRP3 Axis Inhibits the Hippocampal Inflammatory Response in T2DM With OSA

Studies have shown that diabetes can cause cognitive dysfunction, and cognitive dysfunction in patients with diabetes combined with obstructive sleep apnea (OSA) is more severe. LncRNAs are known to be associated with type 2 diabetes mellitus (T2DM) with OSA. This study aimed to investigate the role and underlying mechanism of the lncRNA MALAT1/miR-224-5p/NLRP3 axis in T2DM with OSA. qRT-PCR was used to quantify the expression of MALAT1, miR-224-5p, and NLRP3 in brain tissues. NLRP3 expression was assessed by immunohistochemistry (IHC) and immunofluorescent labeling. The interaction involving MALAT1, miR-224-5p, and NLRP3 was evaluated by transfection. Western blotting was utilized to evaluate the expression levels of the pathway-related proteins NLRP3, caspase 1, tumor necrosis factor-α (TNF-α) and interleukin-1 β (IL-1β) both in vitro and in vivo. qRT-PCR was used to assess the mRNA expression levels of NLRP3, caspase 1, TNF-α and IL-1β both in vitro and in vivo. In brain tissues of T2DM with OSA, MALAT1 and NLRP3 were overexpressed, while miR-224-5p was downregulated, which was consistent with subsequent cell experiments. We screened the miRNAs that could bind to MALAT1 and NLRP3 by the StarBase database and the TargetScanMouse7.2 website. Our research showed that among these miRNAs, the level of miR-224-5p was most significantly negatively correlated with the levels of MALAT1 and NLRP3. Also, a firefly luciferase assay showed that miR-224-5p, which is a target of MALAT1, directly reduced the expression of the downstream protein NLRP3. Overexpression of miR-224-5p significantly inhibited the expression levels of NLRP3, caspase 1, TNF-α and IL-1β in vitro. MALAT1 promoted NLRP3 expression by acting as a competing endogenous RNA and sponging miR-224-5p. MiR-224-5p reduces microglial inflammation activation through the regulation of NLRP3 expression, which ultimately affected the NLRP3/IL-1β pathway in the hippocampus. This suggests that miR-224-5p may serve as a potential target for T2DM and OSA therapy.

Long Noncoding RNA LUADT1 Is Upregulated in Melanoma and May Sponge miR-28-5p to Upregulate RAP1B

Background: Long noncoding RNA (lncRNA) LUADT1 is a known oncogenic lncRNA in lung cancer. This study aimed to explore the roles of LUADT1 in melanoma. Materials and Methods: Sixty pairs of melanoma and nontumor tissues were obtained from 60 melanoma patients (37 men and 23 women, 38-68 years, 52.1 ± 4.9 years) at the First Affiliated Hospital of Zhejiang University School of Medicine. Gene expression was analyzed by quantitative polymerase chain reaction and western blot. Cell transfections were performed to analyze gene expression. Results: We found that LUADT1 was upregulated in melanoma and high levels of LUADT1 predicted poor survival. RNA interaction prediction showed that LUADT1 can form base pairing with miR-28-5p. In melanoma cells, LUADT1 overexpression mediated the upregulated Ras-related protein Rap-1b (RAP1B). Cell proliferation assay showed that LUADT1 and RAP1B overexpression mediated the increased proliferation rate of melanoma cells. In addition, miR-28-5p overexpression played opposite roles attenuating the effects of LUADT1 overexpression on both RAP1B expression and cancer cell proliferation. Conclusions: LUADT1 in melanoma and may sponge miR-28-5p to upregulate RAP1B, thereby promoting cancer cell proliferation.

Long non-coding RNA MALAT1 as a key target in pathogenesis of glioblastoma. Janus faces or Achilles' heal?

Glioblastomas (GBMs) are primary brain tumors with extremely bad prognosis and therefore; discovery of novel regulators of their pathology is of immense importance. LncRNAs (long noncoding RNAs) regulate nuclear structure, embryonic pluripotency, cell differentiation, development and carcinogenesis. Many lncRNAs have weak evolutionary conservation; however, a nuclear lncRNA, MALAT1 (metastasis-associated lung adenocarcinoma transcript 1), is exceptionally conserved and is among the most abundant lncRNAs in benign tissues. The majority of cell culture studies and clinico-epidemiological studies demonstrated that MALAT1 acts a tumor promoter in GBMs and inhibition of MALAT1 suppressed tumor growth in various preclinical models of GBM. MALAT1 involves in stemness of GBM cells by regulating SOX2, nestin and members of WNT pathway. MALAT1 induces protective autophagy and suppresses apoptosis in GBM cells via sponging miRNA-101 and increases temozolomide chemoresistance via enhancing epithelial-mesenchymal transition, suppressing miR-203 and promoting thymidilate synthase. Moreover, knockdown of MALAT1 expression enhances blood-brain tumor barrier permeability via miR-140, which may provide a double benefit of MALAT1 suppression by increasing the delivery of chemotherapy agents into the GBM tissues. On the other hand, there also exist some cell culture and animal studies showing that MALAT1 acts as a tumor suppressor in GBMs by suppression of ERK/MAPK and MMP2 signaling and by repression of miR-155 with subsequent increase of FBXW7. Whether protective or detrimental, MALAT1 seems to be an important component of GBM pathogenesis and hence; novels studies are needed in versatile models, including many different primary GBM cultures, orthotopic and xenogreft in vivo models and transgenic mice.

The lncRNA BCYRN1 Functions as an Oncogene in Human Glioma by Downregulating miR-125a-5p in vitro

Introduction

Numerous studies have demonstrated that long noncoding RNAs (lncRNAs) are deregulated in many cancers and exert their functions through multiple cancer-related biological processes. Glioma is the most common primary malignant central nervous system tumor and has a high fatality rate in adults. In current study, we aimed to determine the role and functional mechanism of the lncRNA BCYRN1 in glioma.

Methods

Gain-of-function and loss-of function approaches were used to investigate the function of BCYRN1. The effects of BCYRN1 on glioma cell proliferation, migration and invasion were evaluated using MTS, Transwell and wound-healing assays. The correlation between the expression of BCYRN1 and miR-125a-5p was verified by quantitative real-time PCR.

Results

The upregulation of BCYRN1 promoted the proliferation, migration and invasion of glioma cells. Meanwhile, the knockdown of BCYRN1 had the opposite effects. BCYRN1 was negatively correlated with miR-125a-5p. Additionally, TAZ, the endogenous target of miR-125a-5p, could be regulated by BCYRN1 in RNA and protein levels. A miR-125a-5p inhibitor restored BCYRN1 siRNA function in glioma.

Conclusion

The present study indicates that BCYRN1 promotes glioma cell proliferation, invasion and migration in vitro. Mechanistically, upregulated expression of BCYRN1 in glioma acts as a sponge to sequester the endogenous tumor suppressor miR-125a-5p and to further increase the expression TAZ. Our findings suggest that BCYRN1 is a novel oncogene and a new therapeutic target for glioma.

LncRNA LOXL1-AS1 promotes endometrial cancer progression by sponging miR-28-5p to upregulate RAP1B expression

BACKGROUND

Increasing lncRNAs are found to be involved in the biological process of multiple cancer types. Herein, we aimed to reveal the role of LOXL1-AS1 in endometrial cancer (EC) progression.

METHODS

Tumor and corresponding normal tissues were obtained from EC patients. Si-LOXL1-AS1 and miR-28-5p inhibitor were transfected to downregulate the expressions of LOXL1-AS1 and miR-28-5p, while miR-28-5p mimics were used to upregulate the miR-28-5p expression. CCK-8 and colony assays were applied to estimate the cell proliferation. Flow cytometry was performed to measure the cell apoptosis. Wound healing and transwell assays were conducted to assess the cell migration and invasion abilities. Informatics analysis was used to explore the relationship among LOXL1-AS1, miR-28-5p and RAP1B.

RESULTS

LOXL1-AS1 was found markedly up-regulated in EC tissues and cell lines. LOXL1-AS1 knockdown displayed evident suppression in cell proliferation, migration and invasion, as well as promotion in cell apoptosis. Moreover, the LOXL1-AS1 induced regulatory effects on EC cells were partially reversed by miR-28-5p inhibitor. Mechanistically, LOXL1-AS1 competitively bond to miR-28-5p, resulting in upregulation of RAP1B. Additionally, in vivo study confirmed the findings discovered in vitro.

CONCLUSIONS

In summary, LOXL1-AS1 exerted oncogenic roles in EC progression by sponging miR-28-5p and thereby upregulating RAP1B. This finding might provide potential targets for EC therapy.

Identification of microRNAs that Regulate the MAPK Pathway in Human Cumulus Cells from PCOS Women with Insulin Resistance

Polycystic ovary syndrome (PCOS) is one of the most common gynaecological endocrine disorders, and more than 60% of PCOS patients have varying degrees of insulin resistance (IR). The regulatory role of microRNAs (miRNAs) at post-transcriptional levels in human cumulus cells relating to IR in PCOS remains unclear. In this case-control study, 26 PCOS patients with IR (PCOS-IR) and 24 patients without IR (PCOS-control) were enrolled. We determined the differentially expressed miRNA and mRNA using next-generation sequencing technology, and these miRNAs and mRNAs were validated by quantitative real-time polymerase chain reaction (PCR). These miRNA regulating pathways (e.g., MAPK pathway) were analysed by bioinformatics analysis, and the Rap1b was demonstrated to be targeted by miR-612 based on quantitative real-time PCR, western blot and luciferase activity assay. A total of 59 known miRNAs and 617 differentially expressed genes were identified that differentially expressed between PCOS-IR and PCOS-control cumulus cells. Moreover, the potential regulating roles of miRNAs and their targeting genes in pathophysiology of IR and PCOS were analysed by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotation, and several key processes were enriched, such as MAPK activity. Furthermore, Rap1b, a regulator of the MAPK pathway, was demonstrated to be suppressed directly by miR-612 in PCOS-IR cumulus cells based on negative expression correlation validation, dual luciferase activity assay and reduction of Rap1b expression after miR-612 mimics transfection. Our results suggested that miRNAs and their targeted pathways in ovarian cumulus cells may play important roles in the aetiology and pathophysiology of PCOS with IR.

Metastasis Associated Lung Adenocarcinoma Transcript 1: An update on expression pattern and functions in carcinogenesis

The Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT1) is among long non-coding RNAs (lncRNAs) which has disapproved the old term of "junk DNA" which was used for majority of human genome which are not transcribed to proteins. An extensive portion of literature points to the fundamental role of this lncRNA in tumorigenesis process of diverse cancers ranging from solid tumors to leukemia. Being firstly identified in lung cancer, it has prognostic and diagnostic values in several cancer types. Consistent with the proposed oncogenic roles for this lncRNA, most of studies have shown up-regulation of MALAT1 in malignant tissues compared with non-malignant/normal tissues of the same source. However, few studies have shown down-regulation of MALAT1 in breast cancer, endometrial cancer, colorectal cancer and glioma. In the current study, we have conducted a comprehensive literature search and provided an up-date on the role of MALAT1 in cancer biology. Our investigation underscores a potential role as a diagnostic/prognostic marker and a putative therapeutic target for MALAT1.

miR-124-3p availability is antagonized by LncRNA-MALAT1 for Slug-induced tumor metastasis in hepatocellular carcinoma

BACKGROUND

As an oncogene, long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) can promote tumor metastasis. Hyperexpression of MALAT1 has been observed in many malignant tumors, including hepatocellular carcinoma (HCC). However, the role and mechanism of MALAT1 in HCC remain unclear.

METHODS

Thirty human HCC and paracancerous tissue specimens were collected, and the human hepatoma cell lines Huh7 and HepG2 were cultured according to standard methods. MALAT1 and Snail family zinc finger (Slug) expression were measured by real-time PCR, immunohistochemistry, and western blotting. Luciferase reporter assay and RNA immunoprecipitation (RIP) assay verified the direct interaction between miR-124-3p and Slug(SNAI2) or MALAT1. Wound healing and transwell assays were performed to examine invasion and migration, and a subcutaneous tumor model was established to measure tumor progression in vivo.

RESULTS

MALAT1 expression was upregulated in HCC tissues and positively correlated with Slug expression. MALAT1 and miR-124-3p bind directly and reversibly to each other. MALAT1 silencing inhibited cell migration and invasion. miR-124-3p inhibited HCC metastasis by targeting Slug.

CONCLUSIONS

MALAT1 regulates Slug through miR-124-3p, affecting HCC cell metastasis. Thus, the MALAT1/miR-124-3p/Slug axis plays an important role in HCC.

MiR-101 relates to chronic peripheral neuropathic pain through targeting KPNB1 and regulating NF-κB signaling

Accumulating evidences indicates that chronic neuropathic pain is a kind of neuro-immune disorder with enhanced activation of the immune system. Although the prevalence is very high, neuropathic pain remains extremely difficult to cure. miRNAs are a group of short nonprotein coding RNAs, regulating target genes expression via targeting 3'-untranslated region. More and more research indicates that altered miRNAs expression profile relates to the pathogenesis of neuropathic pain. In this study, we firstly detected the expression of six candidate miRNAs in the plasma samples from 23 patients with neuropathic pain and 10 healthy controls. Subsequently, the level of miR-132 and miR-101 was detected in the sural nerve biopsies. We found miR-101 level was significantly repressed in both the plasma samples and sural nerve biopsies from neuropathic pain patients. Predicted by bioinformatics tools and confirmed by dual luciferase assay and immunoblotting, we identified that KPNB1 is a direct target of miR-101. The negative correlation between miR-101 and KPNB1 was also confirmed in the sural nerve biopsies, and miR-101 reduction relates to the activation of NF-κB signaling in vivo and in vitro which contributes to the pathogenesis of neuropathic pain.

RNA Expression Profile and Potential Biomarkers in Patients With Spinocerebellar Ataxia Type 3 From Mainland China

Long non-coding RNAs (lncRNAs) play an important role in growth, development, and reproduction and undoubtedly contribute to the pathogenesis and progression of diseases. Emerging evidence suggests the involvement of lncRNAs as regulatory factors in pathological conditions, including some neurodegenerative diseases. Spinocerebellar Ataxia Type 3/Machado–Joseph Disease (SCA3/MJD) has a prominent prevalence in China. Because the role of lncRNAs in SCA3/MJD pathogenesis has not yet been investigated, we conducted a pilot study to investigate the expression profile of lncRNAs by high-throughput sequencing in 12 patients and 12 healthy individuals. The sequencing analysis detected 5,540 known and 2,759 novel lncRNAs. Six lncRNAs were confirmed to be differentially expressed in peripheral blood mononuclear cells between SCA3/MJD patients and healthy individuals and were further validated in cerebellar tissue. Based on these results, NONHSAT022144.2 and NONHSAT165686.1 may be involved in the pathogenesis of SCA3/MJD and may be potential biomarkers for SCA3/MJD. Together with NONHSAT022144.2 and NONHSAT165686.1, the other four novel lncRNAs increase our understanding of lncRNA expression profile.

AC016405.3, a novel long noncoding RNA, acts as a tumor suppressor through modulation of TET2 by microRNA-19a-5p sponging in glioblastoma

Long non-coding RNAs (lncRNAs) are crucial regulators in various malignancies including glioblastoma multiforme (GBM). In the present study, we screened out a new lncRNA, AC016405.3, through a previous genome-wide lncRNA microarray analysis in GBM. It showed that AC016405.3 was downregulated in GBM tissue specimens and cell lines, and it also illustrated that the downregulated AC016405.3 was closely correlated with several aggressive features of patients with GBM. Functionally, we found that overexpression of AC016405.3 suppressed GBM cells' proliferation and metastasis using a gain of function experiment. We further showed that microRNA (miR)-19a-5p, a carcinogenic miRNA, was a downstream miRNA of AC016405.3. AC016405.3 was revealed as a target of miR-19a-5p, and overexpression of miR-19a-5p reversed the inhibitive effect of AC016405.3 on GBM cell proliferation and metastasis. Furthermore, a novel downstream gene of miR-19a-5p, TET2, was identified through a constructed microarray analysis. We showed that TET2 was downregulated in GBM and was involved in miR-19a-5p-mediated proliferation and metastasis by directly being targeted. Finally, through a western blot assay and a series of functional CCK-8 and metastatic assays, we showed that AC016405.3 suppressed proliferation and metastasis through modulation of TET2 by sponging of miR-19a-5p in GBM cells. In summary, the findings of the current study identified a novel lncRNA and illustrated that AC016405.3, acting as an anti-oncogene, suppressed GBM cell proliferation and metastasis by regulating TET through miR-19a-5p sponging. Our present study might provide a new axis in the molecular treatment of GBM.

Temozolomide Treatment Induces lncRNA MALAT1 in an NF-κB and p53 Codependent Manner in Glioblastoma

Alkylating chemotherapy is a central component of the management of glioblastoma (GBM). Among the factors that regulate the response to alkylation damage, NF-κB acts to both promote and block cytotoxicity. In this study, we used genome-wide expression analysis in U87 GBM to identify NF-κB-dependent factors altered in response to temozolomide and found the long noncoding RNA (lncRNA) MALAT1 as one of the most significantly upregulated. In addition, we demonstrated that MALAT1 expression was coregulated by p50 (p105) and p53 via novel κB- and p53-binding sites in the proximal MALAT1 coding region. Temozolomide treatment inhibited p50 recruitment to its cognate element as a function of Ser329 phosphorylation while concomitantly increasing p53 recruitment. Moreover, luciferase reporter studies demonstrated that both κB and p53 cis-elements were required for efficient transactivation in response to temozolomide. Depletion of MALAT1 sensitized patient-derived GBM cells to temozolomide cytotoxicity, and in vivo delivery of nanoparticle-encapsulated anti-MALAT1 siRNA increased the efficacy of temozolomide in mice bearing intracranial GBM xenografts. Despite these observations, in situ hybridization of GBM specimens and analysis of publicly available datasets revealed that MALAT1 expression within GBM tissue was not prognostic of overall survival. Together, these findings support MALAT1 as a target for chemosensitization of GBM and identify p50 and p52 as primary regulators of this ncRNA. SIGNIFICANCE: These findings identify NF-κB and p53 as regulators of the lncRNA MALAT1 and suggest MALAT1 as a potential target for the chemosensitization of GBM.

Differential Exosomic Proteomic Patterns and Their Influence in Resveratrol Sensitivities of Glioblastoma Cells

Glioblastoma multiforme (GBM) is the commonest primary brain malignancy with extremely poor prognosis. Resveratrol posseses anti-cancer effects, while GBM cells respond differently to it due to certain unknown reason(s). Because the tumor-derived exosomes are supposed to influence chemosensitivity, the exosomic proteins released from resveratrol-sensitive U251 and resveratrol-resistant glioblastoma LN428 cells are profiled before (N/Exo) and after drug treatment (Res/Exo) by label-free liquid chromatography-mass spectrometry (LC-MS). The therapeutic implications of the proteomic findings are estimated by gene ontology enrichment analysis (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG)-based bioinformatic analyses and further elucidated by exosome co-incubating. The results reveal that U251/N/Exo but not U251/Res/Exo enhances resveratrol sensitivity of resveratrol-resistant LN428 cells. The resveratrol sensitive properties of U251 cells are not altered by either LN428/N/Exo or LN428/Res/Exo. U251/N/Exo contains higher levels of chromatin silencing and epidermis development proteins, while U251/Res/Exo has more oxygen transport and G protein-coupled receptor. Both of LN428/N/Exo and LN428/Res/Exo are rich in the proteins related with nucleosome assembly, microtubule-based process and chromatin silencing. In conclusion, U251/N/Exo sensitizes LN428 cells to resveratrol via delivering drug sensitizing signals, suggesting the presence of additional factor(s) that may determine the resveratrol sensitivities of glioblastoma cells.

Malat1 long noncoding RNA regulates inflammation and leukocyte differentiation in experimental autoimmune encephalomyelitis

In this study, we investigated the contributions of the MALAT1 long noncoding RNA to autoimmune neuroinflammation in central nervous system tissues from patients with multiple sclerosis (MS) and mice with experimental autoimmune encephalomyelitis (EAE). Expression of MALAT1 was decreased in the spinal cords of EAE mice as well as in stimulated splenocytes and primary macrophages. MALAT1 downregulation by specific siRNAs enhanced the polarization of macrophages towards the M1 phenotype. Interestingly, siRNA-mediated MALAT1 downregulation shifted the pattern of T-cell differentiation towards a Th1/Th17 cell profile and decreased differentiation towards a Tregs phenotype. Proliferation of T-cells was also increased following MALAT1 downregulation. These data point to a potential anti-inflammatory effect for MALAT1 in the context of autoimmune neuroinflammation.