LncRNA MALAT1/miR-129 axis promotes glioma tumorigenesis by targeting SOX2

Exploring the roles and clinical potential of exosome-derived non-coding RNAs in glioma

Non-coding accounts for 98 %-99 % of the human genome and performs many essential regulatory functions in eukaryotes, involved in cancer development and development. Non-coding RNAs are abundantly enriched in exosomes, which play a biological role as vectors. Some biofunctional non-coding RNAs are specifically designed as exosomes for the treatment of cancers such as glioma. Glioma is one of the most common primary tumors within the skull and has varying degrees of malignancy and histologic subtypes of grades I-IV. Gliomas are characterized by high malignancy and an abundant blood supply due to rapid cell proliferation and vascularization, often with a poor prognosis. Exosomal non-coding RNAs can be involved in the tumorigenesis process of glioma from multiple directions, such as angiogenesis, tumor proliferation, metastatic invasion, immune evasion, apoptosis, and autophagy. Therefore, non-coding RNAs in exosomes are suitable as markers or therapeutic targets for early diagnosis of diseases and for predicting the prognosis of a variety of diseases. Regulating exosome production and the level of exosomal non-coding RNA expression may be a new approach to prevent or eliminate glioma. In this review, we review the origin and characteristics of exosomal non-coding RNAs, and introduce the functional studies of exosomal non-coding RNAs in glioma and their potential clinical applications, in order to broaden new ideas for the treatment of glioma.

Innovative perspectives on glioblastoma: the emerging role of long non-coding RNAs

Glioblastoma (GBM) is a highly aggressive and treatment-resistant brain tumor. Recent advancements have highlighted the crucial role of long noncoding RNAs (lncRNAs) in GBM's molecular biology. Unlike protein-coding RNAs, lncRNAs regulate gene expression through transcription, post-transcriptional modifications, and chromatin remodeling. Some lncRNAs, like HOTAIR, CCAT2, CRNDE, and MALAT1, promote GBM development by affecting tumor suppressors and various signaling pathways like PI3K/Akt, mTOR, EGFR, NF-κB, and Wnt/β-catenin. Conversely, certain lncRNAs such as TUG1, MEG3, and GAS8-AS1 act as tumor suppressors and are associated with better prognosis. The study presented in the manuscript aims to explore the involvement of lncRNAs in GBM, focusing on their roles in tumor progression, proliferation, invasion, and potential implications for early detection and immunotherapy. The research seeks to elucidate the mechanisms by which specific lncRNAs influence GBM characteristics and highlight their potential as therapeutic targets or biomarkers in managing this aggressive form of brain cancer.

Targeting epigenetic mechanisms of resistance to chemotherapy in gliomas

Glioma, an aggressive type of brain tumors of glial origin is highly heterogeneous, posing significant treatment challenges due to its intrinsic resistance to conventional therapeutic schemes. It is characterized by an interplay between epigenetic and genetic alterations in key signaling pathways which further endorse their resistance potential. Aberrant DNA methylation patterns, histone modifications and non-coding RNAs may alter the expression of genes associated with drug response and cell survival, induce gene silencing or deregulate key pathways contributing to glioma resistance. There is evidence that epigenetic plasticity enables glioma cells to adapt dynamically to therapeutic schemes and allow the formation of drug-resistant subpopulations. Furthermore, the tumor microenvironment adds an extra input on epigenetic regulation, increasing the complexity of resistance mechanisms. Herein, we discuss epigenetic changes conferring to drug resistance mechanisms in gliomas in order to delineate novel therapeutic targets and potential approaches that will enable personalized treatment.

Retracted article: Knockdown of long non-coding RNA AGAP2-AS1 suppresses the proliferation and metastasis of glioma by targeting microRNA-497-5p

Yi Sun, Yulong Shen and Xing Li. Knockdown of long non-coding RNA AGAP2-AS1 suppresses the proliferation and metastasis of glioma by targeting microRNA-497-5p. Bioengineered. 2021 Oct. doi: 10.1080/21655979.2021.1995573.Since publication, significant concerns have been raised about the compliance with ethical policies for human research and the integrity of the data reported in the article.When approached for an explanation, the authors provided some original data but were not able to provide all the necessary supporting information. As verifying the validity of published work is core to the scholarly record's integrity, we are retracting the article. All authors listed in this publication have been informed.We have been informed in our decision-making by our editorial policies and the COPE guidelines. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as 'Retracted.'

New sights on long non-coding RNAs in glioblastoma: A review of molecular mechanism

Glioma or glioblastoma (GBM) is one of the aggressive and fatal primary cerebral malignancies, with the highest mortality rate among all brain-related tumors. Also, glioma mainly progresses as a more invasive phenotype after primary treatment. Cumulative evidence suggested that dysregulation of noncoding RNAs (ncRNAs) such as long non-coding RNAs (LncRNAs) and microRNAs (miRNAs) are associated with tumor initiation, progression, and drug resistance, through epigenetic modifications, transcriptional, and post-transcriptional processes in the cells. Many scientific investigations have revealed that LncRNAs play important roles in various biological procedures linked with the development and progression of GBM. In recent years, it has been shown that dysregulation of molecular mechanisms in many LncRNAs such as MIR22HG, HULC, AGAP2-AS1, MALAT1, PVT1, TTTY14, HOTAIRM1, PTAR, LPP-AS2, LINC00336, and TINCR are connected with the GBM. Therefore, this scientific review paper focused on the molecular mechanisms of these LncRNAs in the context of GBM.

Detailed pathological role of non-coding RNAs (ncRNAs) in regulating drug resistance of glioblastoma, and update

Glioma is a kind of brain tumor that develops in the central nervous system and is classified based on its histology and molecular genetic features. The lifespan of patients does not exceed 22 months. One of the motives for the low effectiveness of glioma treatment is its radioresistance and chemoresistance. Noncoding RNAs (ncRNAs) are a diverse set of transcripts that do not undergo translation to become proteins in glioma. The ncRNAs have been identified as significant regulators of several biological processes in different cell types and tissues, and their abnormal function has been linked to glioma. They are known to impact important occurrences, including carcinogenesis, progression, and enhanced treatment resistance in glioma cells. The ncRNAs control cell proliferation, migration, epithelial-to-mesenchymal transition (EMT), invasion, and drug resistance in glioma cells. The main focus of this study is to inspect the involvement of ncRNAs in the drug resistance of glioma.

The prognostic value and immunological role of calcium/calmodulin dependent protein kinase kinase 2 (CAMKK2) in pan-cancer study

A thorough assessment of calcium/calmodulin dependent protein kinase kinase 2 (CAMKK2) in pan-cancer studies is currently absent. We integrate multi-omics and clinical data to conduct a molecular landscape of CAMKK2. Gene variation results revealed abnormal high frequency mutations of CAMKK2 in uterine corpus endometrial carcinoma, while expression level analysis demonstrated relatively high expression of CAMKK2 in prostate adenocarcinoma. The aberrant expression of CAMKK2 was found to be predictive of survival outcomes in several cancer types. Additionally, we identified potential regulators of CAMKK2 expression, including miRNAs such as miR.129.1.3p, as well as small-molecule drugs such as EPZ004777, which significantly correlated with CAMKK2 expression. Single-cell transcriptome analysis of kidney renal clear cell carcinoma further revealed a significantly higher expression of CAMKK2 in and monocyte and macrophage M1. Furthermore, in the kidney renal clear cell carcinoma IMvigor210 cohort, patients ongoing immunotherapy with higher CAMKK2 expression experienced a significantly longer median overall survival, but it was observed that in bladder urothelial carcinoma GSE176307 and skin cutaneous melanoma GSE78220 cohorts, CAMKK2 might significantly prolong overall survival. Briefly, CAMKK2 emerges as a promising molecular biomarker that holds potential implications for prognostic evaluation and predicting the effectiveness of immunotherapy across cancers.

Glioblastoma stem cell long non-coding RNAs: therapeutic perspectives and opportunities

Glioblastoma poses a formidable challenge among primary brain tumors: its tumorigenic stem cells, capable of self-renewal, proliferation, and differentiation, contribute substantially to tumor initiation and therapy resistance. These glioblastoma stem cells (GSCs), resembling conventional stem and progenitor cells, adopt pathways critical for tissue development and repair, promoting uninterrupted tumor expansion. Long non-coding RNAs (lncRNAs), a substantial component of the human transcriptome, have garnered considerable interest for their pivotal roles in normal physiological processes and cancer pathogenesis. They display cell- or tissue-specific expression patterns, and extensive investigations have highlighted their impact on regulating GSC properties and cellular differentiation, thus offering promising avenues for therapeutic interventions. Consequently, lncRNAs, with their ability to exert regulatory control over tumor initiation and progression, have emerged as promising targets for innovative glioblastoma therapies. This review explores notable examples of GSC-associated lncRNAs and elucidates their functional roles in driving glioblastoma progression. Additionally, we delved deeper into utilizing a 3D in vitro model for investigating GSC biology and elucidated four primary methodologies for targeting lncRNAs as potential therapeutics in managing glioblastoma.

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.

Plectin plays a role in the migration and volume regulation of astrocytes: a potential biomarker of glioblastoma

BACKGROUND

The expression of aquaporin 4 (AQP4) and intermediate filament (IF) proteins is altered in malignant glioblastoma (GBM), yet the expression of the major IF-based cytolinker, plectin (PLEC), and its contribution to GBM migration and invasiveness, are unknown. Here, we assessed the contribution of plectin in affecting the distribution of plasmalemmal AQP4 aggregates, migratory properties, and regulation of cell volume in astrocytes.

METHODS

In human GBM, the expression of glial fibrillary acidic protein (GFAP), AQP4 and PLEC transcripts was analyzed using publicly available datasets, and the colocalization of PLEC with AQP4 and with GFAP was determined by immunohistochemistry. We performed experiments on wild-type and plectin-deficient primary and immortalized mouse astrocytes, human astrocytes and permanent cell lines (U-251 MG and T98G) derived from a human malignant GBM. The expression of plectin isoforms in mouse astrocytes was assessed by quantitative real-time PCR. Transfection, immunolabeling and confocal microscopy were used to assess plectin-induced alterations in the distribution of the cytoskeleton, the influence of plectin and its isoforms on the abundance and size of plasmalemmal AQP4 aggregates, and the presence of plectin at the plasma membrane. The release of plectin from cells was measured by ELISA. The migration and dynamics of cell volume regulation of immortalized astrocytes were assessed by the wound-healing assay and calcein labeling, respectively.

RESULTS

A positive correlation was found between plectin and AQP4 at the level of gene expression and protein localization in tumorous brain samples. Deficiency of plectin led to a decrease in the abundance and size of plasmalemmal AQP4 aggregates and altered distribution and bundling of the cytoskeleton. Astrocytes predominantly expressed P1c, P1e, and P1g plectin isoforms. The predominant plectin isoform associated with plasmalemmal AQP4 aggregates was P1c, which also affected the mobility of astrocytes most prominently. In the absence of plectin, the collective migration of astrocytes was impaired and the dynamics of cytoplasmic volume changes in peripheral cell regions decreased. Plectin's abundance on the plasma membrane surface and its release from cells were increased in the GBM cell lines.

CONCLUSIONS

Plectin affects cellular properties that contribute to the pathology of GBM. The observed increase in both cell surface and released plectin levels represents a potential biomarker and therapeutic target in the diagnostics and treatment of GBMs.

Roles of lncRNA-MALAT1 in the Progression and Prognosis of Gliomas

Long noncoding RNAs (lncRNAs) represent a large subgroup of RNA transcripts that lack the function of coding proteins and may be essential universal genes involved in carcinogenesis and metastasis. LncRNA metastasis-associated lung adenocarcinoma transcript 1 (lncRNAMALAT1) is overexpressed in various human tumors, including gliomas. However, the biological function and molecular mechanism of action of lncRNA-MALAT1 in gliomas have not yet been systematically elucidated. Accumulating evidence suggests that the abnormal expression of lncRNA-MALAT1 in gliomas is associated with various physical properties of the glioma, such as tumor growth, metastasis, apoptosis, drug resistance, and prognosis. Furthermore, lncRNAs, as tumor progression and prognostic markers in gliomas, may affect tumorigenesis, proliferation of glioma stem cells, and drug resistance. In this review, we summarize the knowledge on the biological functions and prognostic value of lncRNA-MALAT1 in gliomas. This mini-review aims to deepen the understanding of lncRNA-MALAT1 as a novel potential therapeutic target for the individualized precision treatment of gliomas.

Anp32e protects against accumulation of H2A.Z at Sox motif containing promoters during zebrafish gastrulation

Epigenetic regulation of chromatin states is crucial for proper gene expression programs and progression during development, but precise mechanisms by which epigenetic factors influence differentiation remain poorly understood. Here we find that the histone variant H2A.Z accumulates at Sox motif-containing promoters during zebrafish gastrulation while neighboring genes become transcriptionally active. These changes coincide with reduced expression of anp32e, the H2A.Z histone removal chaperone, suggesting that loss of Anp32e may lead to increases in H2A.Z during differentiation. Remarkably, genetic removal of Anp32e in embryos leads to H2A.Z accumulation prior to gastrulation, and precocious developmental transcription of Sox motif associated genes. Altogether, our results provide compelling evidence for a mechanism in which Anp32e restricts H2A.Z accumulation at Sox motif-containing promoters, and subsequent down-regulation of Anp32e enables temporal up-regulation of Sox motif associated genes.

Function of Long Noncoding RNAs in Glioma Progression and Treatment Based on the Wnt/β-Catenin and PI3K/AKT Signaling Pathways

Gliomas are a deadly primary malignant tumor of the central nervous system, with glioblastoma (GBM) representing the most aggressive type. The clinical prognosis of GBM patients remains bleak despite the availability of multiple options for therapy, which has needed us to explore new therapeutic methods to face the rapid progression, short survival, and therapy resistance of glioblastomas. As the Human Genome Project advances, long noncoding RNAs (lncRNAs) have attracted the attention of researchers and clinicians in cancer research. Numerous studies have found aberrant expression of signaling pathways in glioma cells. For example, lncRNAs not only play an integral role in the drug resistance process by regulating the Wnt/β-catenin or PI3K/Akt signaling but are also involved in a variety of malignant biological behaviors such as glioma proliferation, migration, invasion, and tumor apoptosis. Therefore, the present review systematically assesses the existing research evidence on the malignant progression and drug resistance of glioma, focusing on the critical role and potential function of lncRNAs in the Wnt/β-catenin and PI3K/Akt classical pathways to promote and encourage further research in this field.

Induction of lncRNA MALAT1 by hypoxia promotes bone formation by regulating the miR-22-3p/CEBPD axis

Adaptation to hypoxia promotes fracture healing. However, the underlying molecular mechanism remains unknown. Increasing evidence has indicated that long non-coding RNAs (lncRNAs) play crucial roles in several diseases, including fracture healing. In the present study, lncRNA microarray analysis was performed to assess the expression levels of different lncRNAs in MC3T3-E1 cells cultured under hypoxic conditions. A total of 42 lncRNAs exhibited significant differences in their expression, including metastasis associated lung adenocarcinoma transcript 1 (MALAT1), maternally expressed 3, AK046686, AK033442, small nucleolar RNA host gene 2 and distal-less homeobox 1 splice variant 2. Furthermore, overexpression of MALAT1 promoted osteoblast differentiation, alkaline phosphatase (ALP) activity and matrix mineralization of MC3T3-E1 cells, whereas its knockdown diminished hypoxia-induced cell differentiation, ALP activity and matrix mineralization in these cells. Moreover, functional analysis indicated that MALAT1 regulated the mRNA and protein expression levels of CCAAT/enhancer binding protein δ by competitively binding to microRNA-22-3p. Adenoviral-mediated MALAT1 knockdown inhibited fracture healing in a mouse model. Taken together, the results indicated that MALAT1 may serve a role in hypoxia-mediated osteogenesis and bone formation.

m6A-mediated upregulation of LINC01003 regulates cell migration by targeting the CAV1/FAK signaling pathway in glioma

BACKGROUND

Long non-coding RNAs (lncRNAs) play important roles in the progression of glioma. Here, we examined the potential functions of a lncRNA, LINC01003, in glioma and characterized the underlying molecular mechanisms.

METHODS

The GEIPA2 and Chinese Glioma Genome Atlas (CCGA) databases were employed to analyze gene expression and the overall survival curve in patients with glioma. The functions of LINC01003 in glioma growth and migration were assessed by loss-of-function experiments in vitro and in vivo. RNA sequencing was used to determine the signaling pathways effected by LINC01003. Bioinformatics analysis and RNA immunoprecipitation (RIP) assays were used to explore the mechanism underlying the N6-methyladenine (m⁶A) modification-dependent upregulation of LINC01003 in glioma.

RESULTS

LINC01003 expression was upregulated in glioma cell lines and tissues. Higher LINC01003 expression predicted shorter overall survival time in glioma patients. Functionally, LINC01003 knockdown inhibited the cell cycle and cell proliferation and migration in glioma cells. Mechanistically, RNA sequencing revealed that LINC01003 mediated the focal adhesion signaling pathway. Furthermore, LINC01003 upregulation is induced by m⁶A modification regulated by METTL3.

CONCLUSION

This study characterized LINC01003 as a lncRNA that contributes to tumorigenesis in glioma and demonstrated that the LINC01003-CAV1-FAK axis serves as a potential therapeutic target for glioma.

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.

Crosstalk between SOX Genes and Long Non-Coding RNAs in Glioblastoma

Glioblastoma (GBM) continues to be the most devastating primary brain malignancy. Despite significant advancements in understanding basic GBM biology and enormous efforts in developing new therapeutic approaches, the prognosis for most GBM patients remains poor with a median survival time of 15 months. Recently, the interplay between the SOX (SRY-related HMG-box) genes and lncRNAs (long non-coding RNAs) has become the focus of GBM research. Both classes of molecules have an aberrant expression in GBM and play essential roles in tumor initiation, progression, therapy resistance, and recurrence. In GBM, SOX and lncRNAs crosstalk through numerous functional axes, some of which are part of the complex transcriptional and epigenetic regulatory mechanisms. This review provides a systematic summary of current literature data on the complex interplay between SOX genes and lncRNAs and represents an effort to underscore the effects of SOX/lncRNA crosstalk on the malignant properties of GBM cells. Furthermore, we highlight the significance of this crosstalk in searching for new biomarkers and therapeutic approaches in GBM treatment.

Long non-coding RNA in glioma: novel genetic players in temozolomide resistance

Glioma is the most common primary malignant brain tumor in adults and accounts for approximately 80% of brain and central nervous system tumors. In 2021, the World Health Organization (WHO) published a new taxonomy for glioma based on its histological features and molecular alterations. Isocitrate dehydrogenase (IDH) catalyzes the decarboxylation of isocitrate, a critical metabolic reaction in energy generation in cells. Mutations in the IDH genes interrupt cell differentiation and serve as molecular biomarkers that can be used to classify gliomas. For example, the mutant IDH is widely detected in low-grade gliomas, whereas the wild type is in high-grade ones, including glioblastomas. Long non-coding RNAs (lncRNAs) are epigenetically involved in gene expression and contribute to glioma development. To investigate the potential use of lncRNAs as biomarkers, we examined lncRNA dysregulation dependent on the IDH mutation status. We found that several lncRNAs, namely, AL606760.2, H19, MALAT1, PVT1 and SBF2-AS1 may function as glioma risk factors, whereas AC068643.1, AC079228.1, DGCR5, FAM13A-AS1, HAR1A and WDFY3-AS2 may have protective effects. Notably, H19, MALAT1, PVT1, and SBF2-AS1 have been associated with temozolomide resistance in glioma patients. This review study suggests that targeting glioma-associated lncRNAs might aid the treatment of glioma.

Intermedin induces autophagy and attenuates hypoxia-induced injury in cardiomyocytes by regulation of MALAT1/ULK1

Myocardial infarction is a predominant cause of cardiovascular diseases with high incidence and death rate worldwide. Although growing evidence has suggested that IMD has significant protective influences on the cardiovascular system, the molecular regulatory mechanism of IMD in hypoxia-induced injury caused by myocardial infarction is urgent to be elucidated. In the present study, we found hypoxia led to a noteworthy enhancement in IMD expression and IMD alleviated hypoxia-induced myocardial injury of NRCMs. Furthermore, IMD was proved to inhibit hypoxia-induced injury by regulating MALAT1. Our findings suggested MALAT1 positively regulated the mRNA and protein expression level of ULK1 and hypoxia induced autophagy of NRCMs. MALAT1 stimulated autophagy to block hypoxia-induced cell injury in NRCMs via upregulation of ULK1 expression. Autophagy suppression abolished the protective capability of IMD overexpression against hypoxia-induced myocardial injury in NRCMs. In a word, our study shed light on the central mechanism of IMD in preventing hypoxia-induced injury caused by myocardial infarction. We confirmed IMD induced autophagy and attenuated hypoxia-induced injury in cardiomyocytes via MALAT1/ULK1, which may contribute to designing effective therapeutic approaches of myocardial infarction.

Role of Long Intergenic Noncoding RNAs in Cancers with an Overview of MicroRNA Binding

Long intergenic noncoding RNAs are transcripts originating from the regions without annotated coding genes. They are located mainly in the nucleus and regulate gene expression. Long intergenic noncoding RNAs can be also found in the cytoplasm acting as molecular sponges of certain microRNAs. This is crucial in various biological and signaling pathways. Expression levels of many long intergenic noncoding RNAs are disease related. In this article, we focus on the long intergenic noncoding RNAs and their relation to different types of cancer. Studies showed that abnormal expression of long intergenic noncoding RNA deregulates signaling pathways due to the disrupted free microRNA pool. Hampered signaling pathways leads to abnormal cell proliferation and restricts cell death, thus resulting in oncogenesis. This review highlights promising therapeutic targets and enables the identification of potential biomarkers specific for a certain type of cancer. Moreover, we provide an outline of long intergenic noncoding RNAs/microRNA axes, which might be applied in further detailed experiments broadening our knowledge about the cellular role of those RNA species.

Signaling pathways governing glioma cancer stem cells behavior

Glioma is the most common malignant brain tumor that develops in the glial tissue. Several studies have identified that glioma cancer stem cells (GCSCs) play important roles in tumor-initiating features in malignant gliomas. GCSCs are a small population in the brain that presents an essential role in the metastasis of glioma cells to other organs. These cells can self-renew and differentiate, which are thought to be involved in the pathogenesis of glioma. Therefore, targeting GCSCs might be a novel strategy for the treatment of glioma. Accumulating evidence revealed that several signaling pathways, including Notch, TGF-β, Wnt, STAT3, AKT, and EGFR mediated GCSC growth, proliferation, migration, and invasion. Besides, non-coding RNAs (ncRNAs), including miRNAs, circular RNAs, and long ncRNAs have been found to play pivotal roles in the regulation of GCSC pathogenesis and drug resistance. Therefore, targeting these pathways could open a new avenue for glioma management. In this review, we summarized critical signaling pathways involved in the stimulation or prevention of GCSCs tumorigenesis and invasiveness.

Non-coding RNAs and glioma: Focus on cancer stem cells

Glioblastoma and gliomas can have a wide range of histopathologic subtypes. These heterogeneous histologic phenotypes originate from tumor cells with the distinct functions of tumorigenesis and self-renewal, called glioma stem cells (GSCs). GSCs are characterized based on multi-layered epigenetic mechanisms, which control the expression of many genes. This epigenetic regulatory mechanism is often based on functional non-coding RNAs (ncRNAs). ncRNAs have become increasingly important in the pathogenesis of human cancer and work as oncogenes or tumor suppressors to regulate carcinogenesis and progression. These RNAs by being involved in chromatin remodeling and modification, transcriptional regulation, and alternative splicing of pre-mRNA, as well as mRNA stability and protein translation, play a key role in tumor development and progression. Numerous studies have been performed to try to understand the dysregulation pattern of these ncRNAs in tumors and cancer stem cells (CSCs), which show robust differentiation and self-regeneration capacity. This review provides recent findings on the role of ncRNAs in glioma development and progression, particularly their effects on CSCs, thus accelerating the clinical implementation of ncRNAs as promising tumor biomarkers and therapeutic targets.

Long Noncoding RNAs in CNS Myelination and Disease

Myelination by oligodendrocytes is crucial for neuronal survival and function, and defects in myelination or failure in myelin repair can lead to axonal degeneration and various neurological diseases. At present, the factors that promote myelination and overcome the remyelination block in demyelinating diseases are poorly defined. Although the roles of protein-coding genes in oligodendrocyte differentiation have been extensively studied, the majority of the mammalian genome is transcribed into noncoding RNAs, and the functions of these molecules in myelination are poorly characterized. Long noncoding RNAs (lncRNAs) regulate transcription at multiple levels, providing spatiotemporal control and robustness for cell type-specific gene expression and physiological functions. lncRNAs have been shown to regulate neural cell-type specification, differentiation, and maintenance of cell identity, and dysregulation of lncRNA function has been shown to contribute to neurological diseases. In this review, we discuss recent advances in our understanding of the functions of lncRNAs in oligodendrocyte development and myelination as well their roles in neurological diseases and brain tumorigenesis. A more systematic characterization of lncRNA functional networks will be instrumental for a better understanding of CNS myelination, myelin disorders, and myelin repair.

LINC00662 Promotes Proliferation and Invasion and Inhibits Apoptosis of Glioma Cells Through miR-483-3p/SOX3 Axis

LINC00662 plays a prominent role in the carcinogenesis and progression of diverse cancers. However, its biological functions in glioma are still unclear. LINC00662 expression in glioma tissue samples and cell lines was examined by quantitative real-time polymerase chain reaction. The correlation between LINC00662 expression and the clinical characteristics of 50 patients with glioma was analyzed. LINC00662 knockdown and overexpression cell lines were constructed, and the effects of LINC00662 on the proliferation, invasion, and apoptosis of glioma cells were evaluated by cell counting kit-8, 5-ethynyl-2'-deoxyuridine, Transwell, and flow cytometry assays, respectively. Besides, the relationships among LINC00662, miR-483-3p, and sex-determining region Y-box 3 (SOX3) were assessed by dual-luciferase reporter assay and RNA immunoprecipitation assay. Western blot was used to detect the regulatory effects of LINC00662 and miR-483-3p on SOX3 expression in glioma cells. LINC00662 expression level was elevated in glioma tissues and cell lines compared to that in normal tissues and cell lines. LINC00662 high expression was associated with the adverse prognosis of patients with glioma. Knockdown of LINC00662 repressed the proliferation and invasion of glioma cells, and promoted apoptosis. Additionally, it was revealed that LINC00662 acted as the molecular sponge of miR-483-3p, and SOX3 was verified as a direct target of miR-483-3p. The inhibition of miR-483-3p expression and SOX3 overexpression reversed the biological effects of LINC00662 knockdown on glioma cells. This study reports the key regulatory role of LINC00662/miR-483-3p/SOX3 axis in the tumorigenesis and progression of glioma, bringing novel insights into the underlying mechanisms of glioma.

Competitive Endogenous RNA Network Involving miRNA and lncRNA in Non-Hodgkin Lymphoma: Current Advances and Clinical Perspectives

Non-Hodgkin lymphoma (NHL) is a heterogeneous malignancy with variable patient outcomes. There is still a lack of understanding about the different players involved in lymphomagenesis, and the identification of new diagnostic and prognostic biomarkers is urgent. MicroRNAs and long non-coding RNAs emerged as master regulators of B-cell development, and their deregulation has been associated with the initiation and progression of lymphomagenesis. They can function by acting alone or, as recently proposed, by creating competing endogenous RNA (ceRNA) networks. Most studies have focused on individual miRNAs/lncRNAs function in lymphoma, and there is still limited data regarding their interactions in lymphoma progression. The study of miRNAs' and lncRNAs' deregulation in NHL, either alone or as ceRNAs networks, offers new insights into the molecular mechanisms underlying lymphoma pathogenesis and opens a window of opportunity to identify potential diagnostic and prognostic biomarkers. In this review, we summarized the current knowledge regarding the role of miRNAs and lncRNAs in B-cell lymphoma, including their interactions and regulatory networks. Finally, we summarized the studies investigating the potential of miRNAs and lncRNAs as clinical biomarkers, with a special focus on the circulating profiles, to be applied as a non-invasive, easy-to-obtain, and reproducible liquid biopsy for dynamic management of NHL patients.

The Impact of Epigenetic Modifications on Adaptive Resistance Evolution in Glioblastoma

Glioblastoma (GBM) is a highly lethal cancer that is universally refractory to the standard multimodal therapies of surgical resection, radiation, and chemotherapy treatment. Temozolomide (TMZ) is currently the best chemotherapy agent for GBM, but the durability of response is epigenetically dependent and often short-lived secondary to tumor resistance. Therapies that can provide synergy to chemoradiation are desperately needed in GBM. There is accumulating evidence that adaptive resistance evolution in GBM is facilitated through treatment-induced epigenetic modifications. Epigenetic alterations of DNA methylation, histone modifications, and chromatin remodeling have all been implicated as mechanisms that enhance accessibility for transcriptional activation of genes that play critical roles in GBM resistance and lethality. Hence, understanding and targeting epigenetic modifications associated with GBM resistance is of utmost priority. In this review, we summarize the latest updates on the impact of epigenetic modifications on adaptive resistance evolution in GBM to therapy.

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.

Interplay between SOX9 transcription factor and microRNAs in cancer

SOX transcription factors are critical regulators of development, homeostasis and disease progression and their dysregulation is a common finding in various cancers. SOX9 belongs to SOXE family located on chromosome 17. MicroRNAs (miRNAs) possess the capacity of regulating different transcription factors in cancer cells by binding to 3'-UTR. Since miRNAs can affect differentiation, migration, proliferation and other physiological mechanisms, disturbances in their expression have been associated with cancer development. In this review, we evaluate the relationship between miRNAs and SOX9 in different cancers to reveal how this interaction can affect proliferation, metastasis and therapy response of cancer cells. The tumor-suppressor miRNAs can decrease the expression of SOX9 by binding to the 3'-UTR of mRNAs. Furthermore, the expression of downstream targets of SOX9, such as c-Myc, Wnt, PI3K/Akt can be affected by miRNAs. It is noteworthy that other non-coding RNAs including lncRNAs and circRNAs regulate miRNA/SOX9 expression to promote/inhibit cancer progression and malignancy. The pre-clinical findings can be applied as biomarkers for diagnosis and prognosis of cancer patients.

LncRNA NEAT1 promotes malignant phenotypes and TMZ resistance in glioblastoma stem cells by regulating let-7g-5p/MAP3K1 axis

Glioblastoma multiforme (GBM) is one of the most malign brain tumors in adults. Temozolomide (TMZ) is an oral chemotherapy drug constituting the backbone of chemotherapy regimens utilized as first-line treatment of GBM. However, resistance to TMZ often leads to treatment failure. In the present study, we explored the expression and related mechanisms of nuclear enriched abundant transcript 1 (NEAT1) in glioma stem cells (GSCs). Quantitative real-time PCR (qRT-PCR) showed that NEAT1 was up-regulated in serum samples of GBM patients and GSCs isolated from U87, U251 cell lines. Functional experiments showed that NEAT1 knockdown restrained malignant behaviors of GSC, including proliferation, migration and invasion. Dual-luciferase assays identified let-7g-5p was a downstream target and negatively adjusted by NEAT1. Restoration of let-7g-5p impeded tumor progression by inhibiting proliferation, migration and invasion. Mitogen-activated protein kinase kinase kinase 1 (MAP3K1), as a direct target of let-7g-5p, was positively regulated by NEAT1 and involved to affect the regulation of NEAT1 on GSCs' behaviors. In conclusion, our results suggested that NEAT1 promoted GSCs progression via NEAT1/let-7g-5p/MAP3K1 axis, which provided a depth insight into TMZ resistance mechanism.

Diagnostic, prognostic, and therapeutic significance of long non-coding RNA MALAT1 in cancer

Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT1) is a widely studied lncRNA in cancer. Although dispensable for normal physiology, MALAT1 is important for cancer-related pathways regulation. It is localized in the nuclear speckles periphery along with centrally located pre-RNA splicing factors. MALAT1 associated cancer signaling pathways include MAPK/ERK, PI3K/AKT, β-catenin/Wnt, Hippo, VEGF, YAP, etc. Molecular tools such as immunoprecipitation, RNA pull-down, reporter assay, Northern blotting, microarray, and q-RT-PCR has been used to elucidate MALAT1's function in cancer pathogenesis. MALAT1 can regulate multiple steps in the development of tumours. The diagnostic and prognostic significance of MALAT1 has been demonstrated in cancers of the breast, cervix, colorectum, gallbladder, lung, ovary, pancreas, prostate, glioma, hepatocellular carcinoma, and multiple myeloma. MALAT1 has also emerged as a novel therapeutic target for solid as well as hematological malignancies. In experimental models, siRNA and antisense oligonucleotide (ASO) based strategy has been used for targeting MALAT1. The lncRNA has also been targeted for the chemosensitization and radiosensitization of cancer cells. However, most studies have been performed in preclinical models. How the cross-talk of MALAT1 with other signaling pathways affect cancer pathogenesis is the focus of this article. The diagnostic, prognostic, and therapeutic significance of MALAT1 in multiple cancer types are discussed.

Long noncoding RNA SNHG9 facilitates growth of glioma stem-like cells via miR-326/SOX9 axis

BACKGROUND

Glioma stem-like cells (GSCs) are greatly responsible for the progression of glioma. Long noncoding RNAs (lncRNAs) play an important role in glioma tumor progression. This study aims to explore the role and underlying mechanism of lncRNA SNHG9 in regulating GSC cell growth.

METHODS

GSCs were obtained from glioma cells (U87 and U251) and referred to as GSC-87 and GSC-251, respectively. The interactions between miR-326 and SNHG9 or SOX9 were analyzed using luciferase reporter assay. Cell growth of GSCs was evaluated by EdU assay and sphere formation assay.

RESULTS

SNHG9 expression was significantly higher in GSC-87 and GSC-251 cells than in U87 and U251 cells. SNHG9 overexpression promoted GSC cell growth, whereas SNHG9 knockdown inhibited GSC cell growth. Mechanistically, SNHG9 acted as a competitive endogenous RNA of miR-326 to elevate the expression of SOX9, a direct target of miR-326. Moreover, transfection with miR-326 inhibitor counteracted SNHG9 knockdown-mediated inhibition of GSC cell growth.

CONCLUSIONS

SNHG9 facilitates growth of GSCs via the miR-326/SOX9 axis. This study provides a promising therapeutic target for glioma treatment.

Long Non-Coding RNAs in Multidrug Resistance of Glioblastoma

Glioblastoma, also known as glioblastoma multiforme, is the most aggressive brain tumor in adults. Despite the huge advance in developing novel therapeutic strategies for patients with glioblastoma, the appearance of multidrug resistance (MDR) against the common chemotherapeutic agents, including temozolomide, is considered as one of the important causes for the failure of glioblastoma treatment. On the other hand, recent studies have demonstrated the critical roles of long non-coding RNAs (lncRNAs), particularly in the development of MDR in glioblastoma. Therefore, this article aimed to review lncRNA's contribution to the regulation of MDR and elucidate the underlying mechanisms in glioblastoma, which will open up new lines of inquiry in the treatment of glioblastoma.

Studies on the Regulatory Roles and Related Mechanisms of lncRNAs in the Nervous System

Long noncoding RNAs (lncRNAs) have attracted extensive attention due to their regulatory role in various cellular processes. Emerging studies have indicated that lncRNAs are expressed to varying degrees after the growth and development of the nervous system as well as injury and degeneration, thus affecting various physiological processes of the nervous system. In this review, we have compiled various reported lncRNAs related to the growth and development of central and peripheral nerves and pathophysiology (including advanced nerve centers, spinal cord, and peripheral nervous system) and explained how these lncRNAs play regulatory roles through their interactions with target-coding genes. We believe that a full understanding of the regulatory function of lncRNAs in the nervous system will contribute to understand the molecular mechanism of changes after nerve injury and will contribute to discover new diagnostic markers and therapeutic targets for nerve injury diseases.

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.

The role of a ceRNA regulatory network based on lncRNA MALAT1 site in cancer progression

As a type of non-coding RNA of more than 200 nucleotides, long non-coding RNAs(lncRNAs) lack protein coding ability and can regulate gene expression. MicroRNAs(miRNAs), which are also non-coding RNAs, are short single-stranded RNAs, usually composed of 18-23 nucleotides. MiRNAs inhibits gene expression by specifically binding to the 3'-UTR of downstream target mRNAs and can function as oncogenes or suppressor oncogenes to regulate the occurrence and development of cancer. LncRNAs can function as competitive endogenous RNAs that bind to miRNAs, resulting in the recovery of downstream mRNA expression and activity. The regulatory network existing between lncRNAs, miRNAs and mRNAs regulates a variety of biological processes, including cell proliferation, apoptosis, migration and invasion as well as cell-cycle arrest. Disruption of the ceRNA network affects cell growth and development and often leads to various diseases, especially cancer. The lncRNA MALAT1, which is located on chromosome 11q13, contains more than 8000 nucleotides and is implicated in the occurrence and development of many cancers. Here, we review the impact of the ceRNA network and the lncRNA MALAT1 in cancer.

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.

A three-lncRNA signature of pretreatment biopsies predicts pathological response and outcome in esophageal squamous cell carcinoma with neoadjuvant chemoradiotherapy

BACKGROUND

Current strategies are insufficient to predict pathologically complete response (pCR) for esophageal squamous cell carcinomas (ESCCs) before treatment. Here, we aim to develop a novel long noncoding RNA (lncRNA) signature for pCR and outcome prediction of ESCCs through a multicenter analysis for a Chinese population.

METHODS

Differentially expressed lncRNAs (DELs) between pCRs and less than pCR (

RESULTS

Twelve DELs were identified from Guangzhou cohort and six lncRNAs were verified. Then, a classifier of three lncRNAs (SCAT1, PRKAG2-AS1, and FLG-AS1) was established and achieved a high accuracy with an area under the receiver operating characteristic curve (AUC) of 0.952 in the training cohort, which was well validated in the internal validation cohort and external cohort with the AUCs of 0.856 and 0.817, respectively. Furthermore, the predictive score was identified as the only independent predictor for pCR. Patients with high discriminant score showed a significantly longer overall and relapse-free survival (P < .05).

CONCLUSIONS

We developed the first and applicable three-lncRNA signature of pCR and outcome prediction, which is robust and reproducible in multicenter cohorts for ESCCs with nCRT.

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Key Words

• esophageal squamous cell carcinoma
• individualized medicine
• lncRNAs
• neoadjuvant chemoradiotherapy
• pathologically complete response

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MESH Headings Collapse

Grants

• 2017-I2M-1-005 CAMS Innovation Fund for Medical Sciences
• 2016-I2M-1-001 CAMS Innovation Fund for Medical Sciences
• 2016YFC1303201 National Key R&D Program of China
• 81802299 National Natural Science Foundation of China
• 81502514 National Natural Science Foundation of China
• 3332018070 Fundamental Research Funds for the Central Universities
• 2018YFC1312105 National Key Basic Research Development Plan
• 7204291 Beijing Natural Science Foundation
• LC2019B18 Beijing Hope Run Special Fund of Cancer Foundation of China
• National Natural Science Foundation of China
• Fundamental Research Funds for the Central Universities
• Beijing Natural Science Foundation

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Affiliation(s)

Chaoqi Zhang Department of Thoracic SurgeryNational Cancer CenterNational Clinical Research Center for CancerCancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
Zhihui Zhang Department of Thoracic SurgeryNational Cancer CenterNational Clinical Research Center for CancerCancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
Guochao Zhang Department of Thoracic SurgeryNational Cancer CenterNational Clinical Research Center for CancerCancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
Liyan Xue Department of PathologyNational Cancer CenterNational Clinical Research Center for CancerCancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
Haijun Yang Department of PathologyAnyang Cancer HospitalThe Fourth Affiliated Hospital of Henan University of Science and TechnologyAnyangHenanChina
Yuejun Luo Department of Thoracic SurgeryNational Cancer CenterNational Clinical Research Center for CancerCancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
Xiaoli Zheng Department of radiotherapyThe Affiliated Cancer hospital of Zhengzhou UniversityZhengzhouHenanChina
Yonglei Zhang Department of General SurgeryThe Affiliated Cancer Hospital of Zhengzhou UniversityZhengzhouHenanChina
Yufen Yuan Department of PathologyAnyang Cancer HospitalThe Fourth Affiliated Hospital of Henan University of Science and TechnologyAnyangHenanChina
Ruixue Lei Department of PathologyAnyang Cancer HospitalThe Fourth Affiliated Hospital of Henan University of Science and TechnologyAnyangHenanChina
Zhaoyang Yang Department of PathologyNational Cancer CenterNational Clinical Research Center for CancerCancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
Bo Zheng Department of PathologyNational Cancer CenterNational Clinical Research Center for CancerCancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
Zhen Zhang Biotherapy CenterThe First Affiliated Hospital of Zhengzhou UniversityZhengzhouHenanChina
Le Wang Department of OtologyThe First Affiliated Hospital of Zhengzhou UniversityZhengzhouHenanChina
Yun Che Department of Thoracic SurgeryNational Cancer CenterNational Clinical Research Center for CancerCancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
Sihui Wang Department of Thoracic SurgeryNational Cancer CenterNational Clinical Research Center for CancerCancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
Feng Wang Department of Thoracic SurgeryNational Cancer CenterNational Clinical Research Center for CancerCancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
Lingling Fang Department of Thoracic SurgeryNational Cancer CenterNational Clinical Research Center for CancerCancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
Qingpeng Zeng Department of Thoracic SurgeryNational Cancer CenterNational Clinical Research Center for CancerCancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
Jiagen Li Department of Thoracic SurgeryNational Cancer CenterNational Clinical Research Center for CancerCancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
Shugeng Gao Department of Thoracic SurgeryNational Cancer CenterNational Clinical Research Center for CancerCancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
Qi Xue Department of Thoracic SurgeryNational Cancer CenterNational Clinical Research Center for CancerCancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
Nan Sun Department of Thoracic SurgeryNational Cancer CenterNational Clinical Research Center for CancerCancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
Jie He Department of Thoracic SurgeryNational Cancer CenterNational Clinical Research Center for CancerCancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina

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LINC01094 Down-Regulates miR-330-3p and Enhances the Expression of MSI1 to Promote the Progression of Glioma

Background

This study aims at probing into the expression, function, and mechanism of LINC01094 and miR-330-3p in glioma.

Materials and Methods

qRT-PCR was employed to examine LINC01094 and miR-330-3p expressions in gliomas. After gain-of-function and loss-of-function models were constructed, CCK-8 and Transwell assays were used to detect the proliferation, migration and invasion of LN229 and U251 cells, respectively. Additionally, dual luciferase reporter gene assay was utilized to verify the binding site between m4iR-330-3p and LINC01094, miR-330-3p, and the 3ʹUTR of musashi RNA binding protein 1 (MSI1). Then, RNA pull-down, RIP, qRT-PCR and Western blot were employed to detect the regulatory relationships among LINC01094, miR-330-3p, and MSI1.

Results

The expression of LINC01094 was elevated in glioma tissues and cell lines, and the high expression of LINC01094 was associated with high grade of glioma. In contrast, miR-330-3p was lowly expressed in glioma tissue. Overexpression of LINC01094 or down-regulation of miR-330-3p promoted the proliferation, migration, and invasion of glioma cells, while LINC01094 knockdown or miR-330-3p up-regulation impeded these processes. miR-330-3p was identified as a target miRNA of LINC01094, and it could be negatively regulated by LINC01094. In addition, miR-330-3p antagonized the function of LINC01094 by negatively regulating MSI1.

Conclusion

LINC01094 promotes the proliferation, migration, and invasion of glioma cells by adsorbing miR-330-3p and up-regulating the expression of MSI1.

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.

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.

Overexpression of SOX4 induces up-regulation of miR-126 and miR-195 in LNCaP prostate cancer cell line

The present study aims to investigate the association between SOX4, Wnt signaling, and miRNAs under Wnt3 induction via bioinformatics analysis and functional essays. To briefly explore the expression of SOX4 protein in various types of cancer, we used ONCOMINE, a highly reputable cancer database, for comparison of its expression in prostate carcinoma relative to normal prostate gland. Concomitantly, we used CCLE to plot the copy number of SOX4 against its mRNA expression status in various cancerous cell lines to confirm the carcinogenesis role of SOX4. Afterward, whole profiling expression of microRNA in SOX4-stably expressed LNCaP cell line under the effect of Wnt3A were demonstrated. After identifying microRNA targets, STRING database and MIROB were used to explore the functional connection between proteins and microRNA with proteins. The results from our study shows that over-expressed of SOX4 was confirmed in both carcinogenesis tissue and cancer cell lines in Oncomine and CCLE database. In addition, five miRNAs, miR-16, miR-19a, miR320, miR-195, and miR-126, were differentially expressed in LNCaP cell line induced by Wnt3a. Pathway analysis of these targets proposed interaction networks of SOX4, Wnt3a with miR-126 and miR-195. Altogether, the miRNAs involved in Wnt and SOX4-mediated prostate cancer such as miR-126 and miR-195 could be potential biomarkers in prostate cancer.

MALAT1 knockdown inhibits hypopharyngeal squamous cell carcinoma malignancy by targeting microRNA-194

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is involved in the oncogenesis and progression of various types of cancer. However, the function of MALAT1 in hypopharyngeal squamous cell carcinoma (HSCC) is not completely understood. In the present study, MALAT1 expression levels were determined using reverse transcription-quantitative PCR, and Cell Counting Kit-8, Transwell and flow cytometry assays were performed to investigate the biological functions of HSCC cells. The results indicated that MALAT1 was upregulated in HSCC. MALAT1 knockdown suppressed HSCC cell proliferation, migration and invasion, and promoted apoptosis compared with the control group. Additionally, microRNA (miR)-194 was identified as a target of MALAT1 and was expressed at low levels in HSCC tissues compared with adjacent non-tumor tissues. A miR-194 agomir inhibited malignant cell behaviors, including cell proliferation, migration and invasion, whereas miR-194 antagomir promoted malignant behaviors compared with the corresponding control groups. In addition, the results suggested that MALAT1 knockdown inhibited the malignant behaviors of HSCC cells by binding miR-194. miR-194 inhibition partially reversed the MALAT1 knockdown-induced inhibitory effects on HSCC cells. Furthermore, MALAT1 knockdown combined with miR194 mimics resulted in the lowest tumor volume among all tested groups in vivo. In conclusion, the results of the present study suggested that MALAT1 knockdown suppressed the malignant behavior of HSCC by targeting miR-194; therefore, MALAT1 may serve as a novel therapeutic target for HSCC.

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.

Extracellular Vesicle lncRNA Metastasis-Associated Lung Adenocarcinoma Transcript 1 Released From Glioma Stem Cells Modulates the Inflammatory Response of Microglia After Lipopolysaccharide Stimulation Through Regulating miR-129-5p/High Mobility Group Box-1 Protein Axis

Glioma stem cell (GSC)–derived extracellular vesicles (EVs) can mediate the communication between GSCs and microglia. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) expression in GSCs, EVs, and supernatant was detected by real-time PCR. The direct targeting between MALAT1 and miR-129-5p, miR-129-5p, and HMGB1 were tested with luciferase reporter analysis. The expression and secretion of interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF)-α were determined in lipopolysaccharide-stimulated microglia or miR-129-5p inhibitor transferred to microglia exposed to GSC EVs or EVs derived from siMALAT1 pre-transferred GSCs. MALAT1 was enriched in GSC EVs compared with GSCs, and up-regulated MALAT1 was also observed in microglia upon GSC EVs incubation. The relative expression and secretion of IL-6, IL-8, and TNF-α in lipopolysaccharide-stimulated microglia were up-regulated in the GSC supernatant group, which could be reversed by dimethyl amiloride (DMA) (EV secretion inhibitor) co-administration or si-MALAT1 pre-transfection of GSCs. Luciferase reporter assay testified the direct binding of MALAT1 and miR-129-5p, miR-129-5p, and HMGB1, and si-MALAT1 could up-regulate miR-129-5p expression and down-regulate HMGB1 expression in microglia cells. The concentration of IL-6, IL-8, and TNF-α in lipopolysaccharide-stimulated microglia exposed to EVs from siMALAT1 transfected GSCs could be up-regulated by miR-129-5p inhibition. EVs lncRNA MALAT1 released from GSCs could modulate the inflammatory response of microglia after lipopolysaccharide stimulation through regulating the miR-129-5p/HMGB1 axis.

Tumor-Suppressive Function of lncRNA-MEG3 in Glioma Cells by Regulating miR-6088/SMARCB1 Axis

Objective

Mounting evidence has elaborated the implication of long noncoding RNAs (lncRNAs) in tumorigenesis of several cancers, including glioma. However, little was known about the mechanism of lncRNA maternally expressed gene 3 (MEG3) in the development and progression of glioma. This work is designed to explore the effect of MEG3 on glioma progression and its possible mechanism.

Methods

Expressions of lncRNA-MEG3 and SMARCB1 were detected in human glioblastoma U87 and U251 cell lines. Gain and loss of function of MEG3 or/and miR-6088 was performed in U87 and U251 cells to observe its effect on cell proliferation and migration as well as on epithelial-mesenchymal transition (EMT) related markers. Luciferase reporter gene assay was employed to inspect the interactions among MEG3, miR-6088, and SMARCB1.

Results

MEG3 and SMARCB1 expressions were downregulated in glioma cells. Transfection of pcDNA3.1-MEG3 or pcDNA3.1-SMARCB1 plasmids could clearly block cell proliferation, migration, and EMT progression. MEG3 functions as a sponge for miR-6088, while SMARCB1 is a downstream protein of miR-6088. Transfection of miR-6088 mimic or si-SMARCB1 could obviously reverse the favorable effect of pcDNA3.1-MEG3 on glioma progression.

Conclusion

Collectively, the evidence in this study indicated that MEG3 was downregulated in glioma cells and inhibited proliferation and migration of glioma cells via regulating miR-6088/SMARCB1 axis.

Novel lncRNA PSMG3‑AS1 functions as a miR‑143‑3p sponge to increase the proliferation and migration of breast cancer cells

Long non‑coding RNAs (lncRNAs) are considered to be important regulators in breast cancer. In the present study, the potential mechanisms and functional roles of lncRNA PSMG3‑antisense (AS)1 were investigated in vivo and in vitro. The relative expression levels of lncRNA PSMG3‑AS1 and microRNA (miR)‑143‑3p were determined using reverse‑transcription quantitative PCR. The protein expression levels of collagen type 1 alpha 1 (COL1A1) and proliferating cell nuclear antigen (PCNA) were obtained using western blot analysis. Bioinformatics analysis was used to identify the relationship between PSMG3‑AS1, miR‑143‑3p and COL1A1. Colony forming and Cell Counting Kit‑8 assays were used to detect cell proliferation. Transwell and wound‑healing assays were used to determine cell migration. The results of the present study demonstrated that PSMG3‑AS1 expression was increased in breast cancer tumor tissues and cell lines, and that of miR‑143‑3p was decreased. Knockdown of PSMG3‑AS1 increased the level of miR‑143‑3p expression, which led to the mitigation of proliferation and migration capacity in breast carcinoma cells. Additionally, PSMG3‑AS1 knockdown was demonstrated to reduce the mRNA and protein expression levels of COL1A1. miR‑143‑3p mimic transfection reduced proliferation and migration in MDA‑MB‑231 and MCF‑7 cell lines. Furthermore, miR‑143‑3p inhibition significantly increased the proliferation and migration of breast cancer cells compared with the negative control group. The mRNA and protein expression levels of PCNA were reduced in the MCF‑7 cell line when transfected with miR‑143‑3p mimics and si‑PSMG3‑AS1. However, PCNA expression was increased in cells transfected with a miR‑143‑3p inhibitor. In conclusion, the results of the present study identified a novel lncRNA PSMG3‑AS1, which serves as a sponge for miR‑143‑3p in the pathogenesis of breast cancer. PSMG3‑AS1 may be used as a potential therapeutic target gene in breast cancer treatment.