MATN1-AS1 promotes glioma progression by functioning as ceRNA of miR-200b/c/429 to regulate CHD1 expression

LncRNA SNHG1 acts as a ceRNA for miR-216a-3p to regulate TMBIM6 expression in esophageal squamous cell carcinoma

Background: The long noncoding RNA small nucleolar RNA host gene 1 (SNHG1) has been demonstrated to play a crucial role in the progression of esophageal squamous cell carcinoma (ESCC). The current study aims to explore the deeper molecular mechanisms of SNHG1 in ESCC. Methods: Fifty patients with ESCC were enrolled to assess overall survival. Quantitative real-time PCR was performed to measure the levels of SNHG1, miR-216a-3p, and TMBIM6 in ESCC cells. Functional assessments of SNHG1 on ESCC cells were conducted using CCK-8 assay, flow cytometry, and Transwell assays. Western blot was conducted to detect the protein levels of TMBIM6 and proapoptotic proteins (Calpain and Caspase-12). The interaction among SNHG1, miR-216a-3p, and TMBIM6 was assessed with luciferase reporter assays. Results: Our study revealed that SNHG1 was notably increased in both clinical ESCC samples and cellular lines. Upregulation of SNHG1 in ESCC tissues was indicative of poor overall survival. Functionally, SNHG1 knockdown significantly inhibited the proliferation, migration, and invasion while promoting apoptosis in ESCC cells. Mechanistically, SNHG1 functioned as a competing endogenous RNA by sequestering miR-216a-3p to modulate TMBIM6 levels in ESCC cells. Notably, inhibiting miR-216a-3p or restoring TMBIM6 reversed the inhibitory effect induced by SNHG1 knockdown in ESCC cells. Conclusions: We demonstrate for the first time that SNHG1 may act as a competing endogenous RNA and promote ESCC progression through the miR-216a-3p/TMBIM6 axis. This highlights the potential of SNHG1 as a target for ESCC treatment.

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.

Mutual Regulation of ncRNAs and Chromatin Remodeling Complexes in Normal and Pathological Conditions

Chromatin remodeling is the one of the main epigenetic mechanisms of gene expression regulation both in normal cells and in pathological conditions. In recent years, a growing number of investigations have confirmed that epigenetic regulators are tightly connected and form a comprehensive network of regulatory pathways and feedback loops. Genes encoding protein subunits of chromatin remodeling complexes are often mutated and change their expression in diseases, as well as non-coding RNAs (ncRNAs). Moreover, different mechanisms of their mutual regulation have already been described. Further understanding of these processes may help apply their clinical potential for establishment of the diagnosis, prognosis, and treatment of the diseases. The therapeutic targeting of the chromatin structure has many limitations because of the complexity of its regulation, with the involvement of a large number of genes, proteins, non-coding transcripts, and other intermediary molecules. However, several successful strategies have been proposed to target subunits of chromatin remodeling complexes and genes encoding them, as well as the ncRNAs that regulate the operation of these complexes and direct them to the target gene regions. In our review, we focus on chromatin remodeling complexes and ncRNAs, their mutual regulation, role in cellular processes and potential clinical application.

Epi-miRNAs: Modern mediators of methylation status in human cancers

Methylation of the fundamental macromolecules, DNA/RNA, and proteins, is remarkably abundant, evolutionarily conserved, and functionally significant in cellular homeostasis and normal tissue/organism development. Disrupted methylation imprinting is strongly linked to loss of the physiological equilibrium and numerous human pathologies, and most importantly to carcinogenesis, tumor heterogeneity, and cancer progression. Mounting recent evidence has documented the active implication of miRNAs in the orchestration of the multicomponent cellular methylation machineries and the deregulation of methylation profile in the epigenetic, epitranscriptomic, and epiproteomic levels during cancer onset and progression. The elucidation of such regulatory networks between the miRNome and the cellular methylation machineries has led to the emergence of a novel subclass of miRNAs, namely "epi-miRNAs" or "epi-miRs." Herein, we have summarized the existing knowledge on the functional role of epi-miRs in the methylation dynamic landscape of human cancers and their clinical utility in modern cancer diagnostics and tailored therapeutics. This article is categorized under: RNA in Disease and Development > RNA in Disease.

The new ceRNA crosstalk between mRNAs and miRNAs in intervertebral disc degeneration

Degeneration of the intervertebral disc has been linked to lower back pain. To date, pathophysiological mechanisms of intervertebral disc degeneration (IDD) remain unclear; it is meaningful to find effective diagnostic biomarkers and new therapeutic strategies for IDD. This study aimed to reveal the molecular mechanism of IDD pathogenesis from the multidimensional transcriptomics perspective. Here, we acquired IDD bulk omics datasets (GSE67567 and GSE167199) including mRNA, microRNA expression profiles, and single-cell RNA sequencing (GSE199866) from the public Gene Expression Omnibus (GEO) database. Through principal component analysis and Venn analysis, we found different expression patterns in the IDD transcription level and identified 156 common DEGs in both bulk datasets. GO and KEGG functional analyses showed these dysregulators were mostly enriched in the collagen-containing extracellular matrix, cartilage development, chondrocyte differentiation, and immune response pathways. We also constructed a potentially dysregulated competing endogenous RNA (ceRNA) network between mRNAs and miRNAs related to IDD based on microRNA target information and co-expression analysis of RNA profiles and identified 36 ceRNA axes including ZFP36/miR-155-5p/FOS, BTG2/hsa-miR-185-5p/SOCS3, and COL9A2/hsa-miR-664a-5p/IBA57. Finally, in integrating bulk and single-cell transcriptome data analyses, a total of three marker genes, COL2A1, PAX1, and ZFP36L2, were identified. In conclusion, the key genes and the new ceRNA crosstalk we identified in intervertebral disc degeneration may provide new targets for the treatment of IDD.

Studies on the molecular level changes and potential resistance mechanism of Coreius guichenoti under temperature stimulation

In this study, we used transcriptome and proteome technology to analyze molecular level changes in tissues of Coreius guichenoti cultured at high temperature (HT) and low temperature (LT). We also screened for specific anti-stress genes and proteins and evaluated the relationships between them. We identified 201,803 unigenes and 10,623 proteins. Compared with the normal temperature (NT), 408 genes and 1,204 proteins were up- or down-regulated in brain tissues, respectively, at HT, and the numbers were 8 and 149 at LT. In gill tissues, the numbers were 101 and 1,745 at HT and 27 and 511 at LT. In gill tissues at both temperatures, the degree of down-regulation (average, HT 204.67-fold, LT 443.13-fold) was much greater than that of up-regulation (average, HT 28.69-fold, LT 17.68-fold). The protein expression in brain (average, up 52.67-fold, down 13.54-fold) and gill (average, up 73.02-fold, down 12.92-fold) tissues increased more at HT than at LT. The protein expression in brain (up 3.77-fold, down 4.79-fold) tissues decreased more at LT than at HT, whereas the protein expression in gill (up 8.64-fold, down 4.35-fold) tissues was up-regulated more at LT than at HT. At HT, brain tissues were mainly enriched in pathways related to metabolism and DNA repair; at LT, they were mainly enriched in cancer-related pathways. At both temperatures, gill tissues were mainly enriched in pathways related to cell proliferation, apoptosis, immunity, and inflammation. Additionally, Kyoto Encyclopedia of Genes and Genomes pathway analysis showed more differentially expressed proteins in gill tissues than in brain tissues at HT and LT, and temperature stimulation led to the strengthening of metabolic pathways in both tissues. Of the 96 genes we identified as potentially being highly related to temperature stress (59 from transcriptome and 38 from proteome data), we detected heat shock protein 70 in both the transcriptome and proteome. Our results improved our understanding of the differential relationship between gene expression and protein expression in C. guichenoti. Identifying important temperature stress genes will help lay a foundation for cultivating C. guichenoti, and even other fish species, that are resistant to HT or LT.

An Integrated Immune-Related Bioinformatics Analysis in Glioma: Prognostic Signature’s Identification and Multi-Omics Mechanisms’ Exploration

As the traditional treatment for glioma, the most common central nervous system malignancy with poor prognosis, the efficacy of high-intensity surgery combined with radiotherapy and chemotherapy is not satisfactory. The development of individualized scientific treatment strategy urgently requires the guidance of signature with clinical predictive value. In this study, five prognosis-related differentially expressed immune-related genes (PR-DE-IRGs) (CCNA2, HMGB2, CASP3, APOBEC3C, and BMP2) highly associated with glioma were identified for a prognostic model through weighted gene co-expression network analysis, univariate Cox and lasso regression. Kaplan-Meier survival curves, receiver operating characteristic curves and other methods have shown that the model has good performance in predicting the glioma patients’ prognosis. Further combined nomogram provided better predictive performance. The signature’s guiding value in clinical treatment has also been verified by multiple analysis results. We also constructed a comprehensive competing endogenous RNA (ceRNA) regulatory network based on the protective factor BMP2 to further explore its potential role in glioma progression. Numerous immune-related biological functions and pathways were enriched in a high-risk population. Further multi-omics integrative analysis revealed a strong correlation between tumor immunosuppressive environment/IDH1 mutation and signature, suggesting that their cooperation plays an important role in glioma progression.

Evolving Insights Into the Biological Function and Clinical Significance of Long Noncoding RNA in Glioblastoma

Glioblastoma (GBM) is one of the most prevalent and aggressive cancers worldwide. The overall survival period of GBM patients is only 15 months even with standard combination therapy. The absence of validated biomarkers for early diagnosis mainly accounts for worse clinical outcomes of GBM patients. Thus, there is an urgent requirement to characterize more biomarkers for the early diagnosis of GBM patients. In addition, the detailed molecular basis during GBM pathogenesis and oncogenesis is not fully understood, highlighting that it is of great significance to elucidate the molecular mechanisms of GBM initiation and development. Recently, accumulated pieces of evidence have revealed the central roles of long noncoding RNAs (lncRNAs) in the tumorigenesis and progression of GBM by binding with DNA, RNA, or protein. Targeting those oncogenic lncRNAs in GBM may be promising to develop more effective therapeutics. Furthermore, a better understanding of the biological function and underlying molecular basis of dysregulated lncRNAs in GBM initiation and development will offer new insights into GBM early diagnosis and develop novel treatments for GBM patients. Herein, this review builds on previous studies to summarize the dysregulated lncRNAs in GBM and their unique biological functions during GBM tumorigenesis and progression. In addition, new insights and challenges of lncRNA-based diagnostic and therapeutic potentials for GBM patients were also introduced.

Silencing LINC00294 Restores Mitochondrial Function and Inhibits Apoptosis of Glioma Cells under Hypoxia via the miR-21-5p/CASKIN1/cAMP Axis

Glioma is a type of malignant intracranial tumor. Extensive research has identified the participation of long noncoding RNAs (lncRNAs) in glioma progression. This study investigated the mechanism of LINC00294 in mitochondrial function and glioma cell apoptosis. Glioma miRNA and mRNA microarray datasets were obtained, and differentially expressed lncRNAs in glioma were screened through various databases. The LINC00294 expression in glioma patients and glioma cells was detected. Glioma cells were treated under hypoxic conditions and transfected with LINC00294 silencing. The apoptosis and mitochondrial function of glioma cells were measured. The expressions of and relations among miR-21-5p, CASKIN1, and cAMP in glioma cells were analyzed. Under hypoxic conditions and LINC00294 silencing, the apoptosis and mitochondrial function of glioma cells were detected after inhibiting miR-21-5p or overexpressing CASKIN1. Our results indicated that LINC00294 was downregulated in glioma. LINC00294 silencing inhibited glioma cell apoptosis under hypoxia. LINC00294 silencing reversed the inhibition of hypoxia on mitochondrial function under hypoxia. LINC00294 promoted the CASKIN1 expression by sponging miR-21-5p and activated the cAMP pathway. Inhibition of miR-21-5p or overexpression of CASKIN1 annulled the effects of LINC00294 silencing on mitochondrial function and glioma cell apoptosis under hypoxia. In conclusion, LINC00294 elevated the CASKIN1 expression by sponging miR-21-5p and activating the cAMP signaling pathway, thus inhibiting mitochondrial function and facilitating glioma cell apoptosis.

Construction of a ceRNA network in glioma and analysis of its clinical significance

Background

Glioma is the most common central nervous system tumor with a poor survival rate and prognosis. Previous studies have found that long non-coding RNA (lncRNA) and competitive endogenous RNA (ceRNA) play important roles in regulating various tumor mechanisms. We obtained RNA-Seq data of glioma and normal brain tissue samples from TCGA and GTEx databases and extracted the lncRNA and mRNA expression data. Further, we analyzed these data using weighted gene co-expression network analysis and differential expression analysis, respectively. Differential expression analysis was also carried out on the mRNA data from the GEO database. Further, we predicted the interactions between lncRNA, miRNA, and targeted mRNA. Using the CGGA data to perform univariate and multivariate Cox regression analysis on mRNA.

Results

We constructed a Cox proportional hazard regression model containing four mRNAs and performed immune infiltration analysis. Moreover, we also constructed a ceRNA network including 21 lncRNAs, two miRNAs, and four mRNAs, and identified seven lncRNAs related to survival that have not been previously studied in gliomas. Through the gene set enrichment analysis, we found four lncRNAs that may have a significant role in tumors and should be explored further in the context of gliomas.

Conclusions

In short, we identified four lncRNAs with research value for gliomas, constructed a ceRNA network in gliomas, and developed a prognostic prediction model. Our research enhances our understanding of the molecular mechanisms underlying gliomas, providing new insights for developing targeted therapies and efficiently evaluating the prognosis of gliomas.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-08035-w.

FOXN3 inhibits cell proliferation and invasion via modulating the AKT/MDM2/p53 axis in human glioma

This study aimed to evaluate the biological role of forkhead box N3 (FOXN3) in human glioma and clarify the possible molecular mechanisms. FOXN3 expression patterns in clinical tissue specimens were characterized via qPCR and Western blotting. Kaplan-Meier survival curve was applied to assess the correlation between FOXN3 expression and overall survival. Effects of FOXN3 over-expression and depletion on glioma cell proliferation, apoptosis, migration and invasion were assessed by CCK8, colony formation assay, flow cytometry, scratch wound healing assay and Transwell invasion assay, respectively. Moreover, the involvement of AKT/murine double minute 2 (MDM2)/p53 pathway was evaluated. Additionally, tumor transplantation model assay was performed to determine the effects of FOXN3 over-expression on glioma cell growth in vivo. Results showed that FOXN3 was significantly down-regulated in glioma tissues compared with normal tissues. Patients with lower FOXN3 expression exhibited a shorter overall survival time. Gain- and loss-of-function analyses demonstrated that FOXN3 over-expression significantly suppressed proliferation, survival and motility of glioma cells, whereas FOXN3 knockdown remarkably promoted glioma cell proliferation, survival and motility. Furthermore, FOXN3 over-expression inhibited the activation of AKT/MDM2/p53 signaling pathway in glioma cells, while FOXN3 depletion facilitated its activation. Additionally, tumor xenograft assays revealed that FOXN3 over-expression retarded glioma cell growth in vivo. Collectively, these findings indicate that FOXN3 inhibits cell growth and invasion through inactivating the AKT/MDM2/p53 signaling pathway and that FOXN3-AKT/MDM2/p53 axis may represent a novel therapeutic target for glioma patients.

LncRNA-PVT1 indicates a poor prognosis and promotes angiogenesis via activating the HNF1B/EMT axis in glioma

Recent studies identified that long non-coding RNAs (lncRNAs) exhibited critical roles in tumor migration and invasion. However, the roles of lncRNAs in glioma remain unclear. The aim of this study was to uncover the underlying mechanisms of glioma progression and provide potential therapeutic targets for its treatment in clinic. Our microarray study showed that lncRNA-PVT1 was significantly upregulated in glioma tissues and played an important role in cell proliferation, migration, invasion and angiogenesis. Our data showed that the expression of lncRNA-PVT1 was increased obviously and associated with advanced tumor stage, metastasis, invasion ability, and poor prognosis in glioma patients. Up-regulation of lncRNA-PVT1 was observed to promote glioma cells proliferation, and invasion abilities in vitro as well as tumor growth in vivo by regulating miR-1207-3p expression. Online software (TargetScan, miRDB and miR TarBase) were used to predict the regulating mechanisms of lncRNA-PVT1, miR-1207-3p and HNF1B, which were validated by dual-luciferase reporter gene system. In vivo tumor-bearing mice models were established to validate the cellular results. Therefore, we suggested that lncRNA-PVT1/miR-1207-3p/HNF1B axis might play critical roles in glioma progression, indicating that lncRNA-PVT1/miR-1207-3p/HNF1B signaling axis may serve as novel molecular targets for glioma prevention and treatment.

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.

Roles of Long Noncoding RNAs in Conferring Glioma Progression and Treatment

Accompanying the development of biomedicine, our knowledge of glioma, one of the most common primary intracranial carcinomas, is becoming more comprehensive. Unfortunately, patients with glioblastoma (GBM) still have a dismal prognosis and a high relapse rate, even with standard combination therapy, namely, surgical resection, postoperative radiotherapy and chemotherapy. The absence of validated biomarkers is responsible for the majority of these poor outcomes, and reliable therapeutic targets are indispensable for improving the prognosis of patients suffering from gliomas. Identification of both precise diagnostic and accurate prognostic markers and promising therapeutic targets has therefore attracted considerable attention from researchers. Encouragingly, accumulating evidence has demonstrated that long noncoding RNAs (lncRNAs) play important roles in the pathogenesis and oncogenesis of various categories of human tumors, including gliomas. Nevertheless, the underlying mechanisms by which lncRNAs regulate diverse biological behaviors of glioma cells, such as proliferation, invasion and migration, remain poorly understood. Consequently, this review builds on previous studies to further summarize the progress in the field of lncRNA regulation of gliomas over recent years and addresses the potential of lncRNAs as diagnostic and prognostic markers and therapeutic targets.

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.

Developing Tumor Radiosensitivity Signatures Using LncRNAs

Long non-coding RNAs (lncRNAs) are involved in diverse biological processes, including DNA damage repair, and are of interest as potential biomarkers of radiosensitivity. We investigated whether lncRNA radiosensitivity signatures could be derived for use in cancer patients treated with radiotherapy. Signature development involved radiosensitivity measurements for cell lines and primary tumor samples, and patient outcome after radiotherapy. A 10-lncRNA signature trained on radiosensitivity measurements in bladder cell lines showed a trend towards independent validation. In multivariable analyses, patients with tumors classified as radioresistant by the lncRNA signature had poorer local relapse-free survival (P = 0.065) in 151 patients with muscle-invasive bladder cancer who underwent radiotherapy. An mRNA-based radiosensitivity index signature performed similarly to the lncRNA bladder signature for local relapse-free survival (P = 0.055). Pathway analysis showed the lncRNA signature associated with molecular processes involved in radiation responses. Knockdown of one of the lncRNAs in the signature showed a modest increase in radiosensitivity in one cell line. An alternative approach involved training on primary cervical tumor radiosensitivity or local control after radiotherapy. Both approaches failed to generate a cervix lncRNA radiosensitivity signature, which was attributed to the age of samples in our cohorts. Our work highlights challenges in validating lncRNA signatures as biomarkers in archival tissue from radiotherapy cohorts, but supports continued investigation of lncRNAs for a role in radiosensitivity.

LINC00514 promotes gastric cancer cell growth and EMT progression via miR-204-3p/KRAS

Long noncoding RNAs (LncRNAs) participate in tumor development and tumorigenesis. However, the mechanism, function and expression of LINC00514 in GC remain unknown. We showed that LINC00514 was upregulated in GC specimens compared with nontumor specimens. Overexpression of LINC00514 induced cell growth and EMT progression in GC cells. By using bioinformatics prediction, we found that miR-204-3p contained binding sequences for LINC00514. Luciferase reporter analysis noted that miR-204-3p overexpression decreased the luciferase expression under LINC00514-wild-type and KRAS-wild-type reporters but not that under mutant reporter. Ectopic LINC00514 expression decreased miR-204-3p expression. miR-204-3p expression was decreased in GC specimens compared with nontumor specimens and that LINC00514 was negatively correlated with miR-204-3p in GC specimens. Furthermore, KRAS was identified as a target gene for miR-204-3p according to TargetScan. Elevated miR-204-3p expression inhibited KRAS expression in HGC-27 cells, and ectopic expression of LINC00514 enhanced KRAS expression. Elevated LINC00514 expression enhanced cell growth and EMT progression by sponging KRAS. Our data indicated that LINC00514 may act as an oncogene and therapeutic target for GC.

Explore prognostic biomarker of bladder cancer based on competing endogenous network

Bladder cancer (BC) is the most common tumor of the urinary tract. Increasing evidence showed that long non-coding RNA (lncRNA) is a critical regulator in cancer development and progression. However, the functions of lncRNAs in the development of BC remain mostly undefined. In the present study, based on RNA sequence profiles from The Cancer Genome Atlas database, we identified 723 lncRNAs, 157 miRNAs, and 1816 mRNAs aberrantly expressed in BC tissues. A competing endogenous RNA network, including 49 lncRNAs, 17 miRNAs, and 36 mRNAs, was then established. The functional enrichment analyses showed that the mRNAs in the ceRNA network mainly participated in ‘regulation of transcription’ and ‘pathways in cancer’. Moreover, the Cox regression analyses demonstrated that three lncRNAs (AC112721.1, TMPRSS11GP, and ADAMTS9-AS1) could serve as independent risk factors. We established a risk prediction model with these lncRNAs. Kaplan–Meier curve analysis showed that high-risk patients’ prognosis was lower than that of low-risk patients (P=0.001). The present study provides novel insights into the lncRNA-mediated ceRNA network and the potential of lncRNAs to be candidate prognostic biomarkers in BC, which could help better understand the pathological changes and pathogenesis of BC and be useful for clinical studies in the future.

Long non-coding RNAs: the tentacles of chromatin remodeler complexes

Chromatin remodeler complexes regulate gene transcription, DNA replication and DNA repair by changing both nucleosome position and post-translational modifications. The chromatin remodeler complexes are categorized into four families: the SWI/SNF, INO80/SWR1, ISWI and CHD family. In this review, we describe the subunits of these chromatin remodeler complexes, in particular, the recently identified members of the ISWI family and novelties of the CHD family. Long non-coding (lnc) RNAs regulate gene expression through different epigenetic mechanisms, including interaction with chromatin remodelers. For example, interaction of lncBRM with BRM inhibits the SWI/SNF complex associated with a differentiated phenotype and favors assembly of a stem cell-related SWI/SNF complex. Today, over 50 lncRNAs have been shown to affect chromatin remodeler complexes and we here discuss the mechanisms involved.

Linc00475 promotes the progression of glioma by regulating the miR-141-3p/YAP1 axis

Glioma is the most prevalent and lethal primary brain tumour. Abundant long non‐coding RNAs ( lncRNAs) are aberrant and play crucial roles in the oncogenesis of glioma. The exact functions of linc00475 in glioma remain blurred. Here, we analysed the expression levels of linc00475 by qRT‐PCR and discovered that linc00475 was up‐regulated in glioma and predicted a poor prognosis in patients with glioma. Besides, inhibiting linc00475 restrained the progression of glioma in vitro and in vivo. Further experiments confirmed that linc00475 regulated the progression of glioma by acting as a sponge for miR‐141‐3p. Moreover, we detected the binding sites of linc00475 and miR‐141‐3p, the YAP1‐ 3′UTR and miR‐141‐3p by luciferase reporters. The rescue assays confirmed that inhibiting linc00475 restrained the progression of glioma through the miR‐141‐3p/YAP1 pathway. Collectively, our research demonstrates the key roles of linc00475 in glioma, which could be a promising therapeutic target.

Knockdown of circ-TTBK2 Inhibits Glioma Progression by Regulating miR-1283 and CHD1

Background

Dysregulated circular RNAs (circRNAs) are involved in the development of glioma. This paper aims to analyze the role and mechanism of circRNA tau tubulin kinase 2 (circ-TTBK2) in glioma progression.

Methods

The glioma samples and normal brain tissues were collected. The levels of circ-TTBK2, microRNA-1283 (miR-1283) and chromodomain helicase DNA-binding protein 1 (CHD1) were examined via quantitative reverse transcription polymerase chain reaction or Western blot. Cell proliferation, migration, invasion and glycolysis were determined via 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide, transwell assay, Western blot, glucose and lactate assay kits. The target relationship was analyzed via dual-luciferase reporter assay. The xenograft model was established using U251 cells.

Results

circ-TTBK2 expression was increased in glioma tissues and cells. circ-TTBK2 knockdown suppressed glioma cell proliferation, migration, invasion and glycolysis. circ-TTBK2 was a sponge for miR-1283, and knockdown of miR-1283 reversed the effect of circ-TTBK2 silence on glioma progression. CHD1 was targeted via miR-1283, and miR-1283 repressed glioma cell proliferation, migration, invasion and glycolysis via decreasing CHD1. Knockdown of circ-TTBK2-reduced CHD1 expression by mediating miR-1283. Silence of circ-TTBK2 reduced xenograft tumor growth.

Conclusion

Down-regulation of circ-TTBK2 suppressed glioma development by regulating miR-1283 and CHD1, providing a new mechanism for understanding glioma pathogenesis.

miR-5188 augments glioma growth, migration and invasion through an SP1-modulated FOXO1-PI3K/AKT-c-JUN-positive feedback circuit

The biological effect and molecular mechanism of miR-5188 have not been thoroughly investigated. The study aims at elucidating the role of miR-5188 in glioma progression. Human glioma cell lines and tissues were used for functional and expression analysis. Cellular and molecular techniques were performed to explore the functions and mechanisms of miR-5188 in glioma. In our investigation, we demonstrated that miR-5188 promoted cell proliferation, the G1/S transition of the cell cycle, migration and invasion in glioma and reduced the lifespan of glioma-bearing mice. miR-5188 directly targeted FOXO1 and activated PI3K/AKT-c-JUN signalling, which enhanced miR-5188 expression. Moreover, the c-JUN transcription factor functionally bound to the miR-5188 promoter region, forming the positive feedback loop. The feedback loop promoted glioma progression through activating the PI3K/AKT signalling, and this loop is augmented by the interaction between SP1 and c-JUN. Moreover, it was also found that the miR-5188/FOXO1 axis is facilitated by SP1-activated PI3K/AKT/c-JUN signalling. In glioma samples, miR-5188 expression was found to be an unfavourable factor and was positively associated with the mRNA levels of SP1 and c-JUN, whereas negatively associated with the mRNA levels of FOXO1. Our investigation demonstrates that miR-5188 could function as a tumour promoter by directly targeting FOXO1 and participating in SP1-mediated promotion of cell growth and tumorigenesis in glioma.

Long noncoding RNA NR2F1-AS1 promotes the malignancy of non-small cell lung cancer via sponging microRNA-493-5p and thereby increasing ITGB1 expression

Several studies have reported that the long noncoding ribonucleic acid (lncRNA) NR2F1 antisense RNA 1 (NR2F1-AS1) affects multiple cellular pathways that are involved in tumorigenesis and tumor progression. The present study aimed to detect NR2F1-AS1 expression in non-small cell lung cancer (NSCLC), investigate the role of NR2F1-AS1 in promoting the tumorigenic behavior of NSCLC cells, and elucidate the mechanism underlying the effect of NR2F1-AS1 on NSCLC progression. Our results showed that NR2F1-AS1 expression was upregulated in NSCLC cells, and notably, its upregulation was correlated with adverse clinical characteristics and shorter overall survival in patients with NSCLC. The absence of NR2F1-AS1 functionally decreased NSCLC cell proliferation, migration, and invasion and promoted tumor cell apoptosis. In addition, the tumor growth of NSCLC cells in vivo was inhibited after NR2F1-AS1 silencing. Mechanistically, NR2F1-AS1 functioned as a competing endogenous RNA for miR-493-5p and consequently increased ITGB1 expression. Rescue assays further validated that an increased output of the miR-493-5p/ITGB1 axis could neutralize the regulatory impact of NR2F1-AS1 knockdown on the malignant phenotype of NSCLC cells. In summary, the NR2F1-AS1/miR-493-5p/ITGB1 pathway initiates pro-oncogenic behavior in NSCLC tumor progression, and the NR2F1-AS1/miR-493-5p/ITGB1 axis may provide new molecular targets for anticancer therapy against NSCLC.

TMPO-AS1 promotes cell proliferation of thyroid cancer via sponging miR-498 to modulate TMPO

Background

Thyroid cancer (TC) is the most frequent endocrine malignancy. Long noncoding RNAs (lncRNAs) have been confirmed to act as significant roles in tumor development. The role of lncRNA TMPO-AS1 in TC is still unclear, so it remains to be explored. The aim of the research is to investigate the role and regulatory mechanism of TMPO-AS1 in TC.

Methods

TMPO-AS1 and TMPO expression in TC tumors and cells was detected by TCGA database and QRT-PCR assay respectively. CCK-8, EDU, TUNEL and western blot assays were conducted to identify the biological functions of TMPO-AS1 in TC. Luciferase reporter and RNA pull down assays were conducted to measure the interaction among TMPO-AS1, TMPO and miR-498.

Results

TMPO-AS1 was overexpressed in TC tissues and cell lines. Knockdown of TMPO-AS1 suppressed cell growth and accelerated cell apoptosis in TC. Furthermore, downregulation of TMPO-AS1 suppressed TMPO expression in TC. The data suggested that TMPO expression was upregulated in TC tissues and cell lines and was positively correlated with TMPO-AS1 expression in TC. Furthermore, the expression of miR-498 presented low expression in TC cells. And miR-498 expression was negatively regulated by TMPO-AS1, meanwhile, TMPO expression was negatively regulated by miR-498 in TC cells. Besides, it was confirmed that TMPO-AS1 could bind with miR-498 and TMPO in TC cells. In addition, it was validated that TMPO-AS1 elevated the levels of TMPO via sponging miR-498 in TC cells.

Conclusions

TMPO-AS1 promotes cell proliferation in TC via sponging miR-498 to modulate TMPO.

Transcriptomic Analysis Reveals the Involvement of lncRNA-miRNA-mRNA Networks in Hair Follicle Induction in Aohan Fine Wool Sheep Skin

Long non-coding RNAs (lncRNA) and microRNAs (miRNA) are new found classes of non-coding RNAs (ncRNAs) that are not translated into proteins but regulate various cellular and biological processes. In this study, we conducted a transcriptomic analysis of ncRNA and mRNA expression in Aohan fine wool sheep (AFWS) at different growth stages (embryonic day 90, embryonic day 120, and the day of birth), and explored their relationship with wool follicle growth. In total, 461 lncRNAs, 106 miRNAs, and 1,009 mRNAs were found to be differentially expressed during the three stages of wool follicle development. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed to clarify the roles of the differentially expressed lncRNA, miRNA, and mRNA in the different stages of wool follicle development. Quantitative real-time PCR (qRT-PCR) was used to validate the results of RNA-seq analysis. lncRNA (MSTRG.223165) was found to act as a competing endogenous RNA (ceRNA) and may participate in wool follicle development by acting as an miR-21 sponge. Network prediction implicated the MSTRG.223165-miR-21-SOX6 axis in the wool follicle development. The targeting relationships of miR-21 with SOX6 and MSTRG.223165 were validated in dual-luciferase assays. This is the first report indicating the association of the lncRNA-miRNA-mRNA network with wool follicle development in AFWS. This study provides new insights into the regulation of the wool follicle growth and represents a solid foundation for wool sheep breeding programs.

LINC00667 promotes Wilms' tumor metastasis and stemness by sponging miR-200b/c/429 family to regulate IKK-β

Wilms' tumor, also known as nephroblastoma, is a kind of pediatric renal cancer. Previous studies have indicated that microRNAs (miRNAs) regulate various cancers progression. However, whether miR-200 family regulated Wilms' tumor progression remains to be elucidated. In our study, miR-200b/c/429 expression was downregulated in Wilms' tumor tissue samples from 25 patients. And data from three independent analyses of quantitative real-time polymerase chain reaction revealed that the expression of miR-200b/c/429 was downregulated in Wilms' tumor cell lines. Functionally, Cell counting kit-8 assay revealed that cell viability was reduced by overexpressing miR-200b/c/429. Transwell assay manifested that cell migration and invasion was hindered by miR-200b/c/429 overexpression. Sphere-forming and western blot assays demonstrated that miR-200b/c/429 overexpression suppressed the sphere formation ability. Mechanically, nuclear factor-κB (NF-κB) pathway was confirmed to be associated with Wilms' tumor progression; miR-200b/c/429 overexpression inactivated NF-κB pathway as miR-200b/c/429 was identified to target IκB kinase β (IKK-β), an NF-κB pathway-related gene. Moreover, miR-200b/c/429 was sponged by LINC00667 in Wilms' tumor cells. LINC00667 competitively bound with miR-200b/c/429 to regulate IKK-β expression and then activated NF-κB pathway in Wilms' tumor. Subsequently, rescue assays illustrated that silencing of IKK-β could reverse the effect of miR-200b/c/429 inhibition on the progression of sh-LINC00667-transfected Wilms' tumor cells. In summary, LINC00667 promoted Wilms' tumor progression by sponging miR-200b/c/429 family to regulate IKK-β.

Hsa_circ_001680 affects the proliferation and migration of CRC and mediates its chemoresistance by regulating BMI1 through miR-340

BACKGROUND

Accumulating evidence indicates that circular RNAs (circRNAs) act as microRNA (miRNA) sponges to directly inhibit specific miRNAs and alter their ability to regulate gene expression at the post-transcriptional level; this mechanism is believed to occur in various cancers. However, the expression level, precise function and mechanism of circ_001680 in colorectal carcinoma (CRC) are largely unknown.

METHODS

qRT-PCR was used to detect the expression of circ_001680 and miR-340 in human CRC tissues and their matched normal tissues. Bioinformatics analyses and dual-fluorescence reporter assays were used to evaluate whether circ_001680 could bind to miR-340. Circ_001680 overexpression and knockdown cell lines were constructed to investigate the proliferation and migration abilities in vivo and in vitro through function-based experiments, including CCK8, plate clone formation, transwell, and wounding healing assays. The relationships among circ_001680, miR-340 and BMI1 were investigated by bioinformatics analyses, dual-fluorescence reporter system, FISH, RIP and RNA pull down assays. Sphere forming assays and flow cytometry analyses were used to assess the effect of circ_001680 on the stemness characteristics of CRC cells.

RESULTS

Circ_001680 was more highly expressed in of CRC tissue than in matched adjacent normal tissues from the same patients. Circ_001680 was observed to enhance the proliferation and migration capacity of CRC cells. Furthermore, dual-fluorescence reporter assays confirmed that circ_001680 affects the expression of BMI1 by targeting miR-340. More importantly, we also found that circ_001680 could promote the cancer stem cell (CSC) population in CRC and induce irinotecan therapeutic resistance by regulating the miR-340 target gene BMI1.

CONCLUSIONS

Our results demonstrated that circ_001680 is a part of a novel strategy to induce chemotherapy resistance in CRC through BMI1 upregulation. Moreover, circ_001680 may be a promising diagnostic and prognostic marker to determine the success of irinotecan-based chemotherapy.

MATN1-AS1 promotes glioma progression by functioning as ceRNA of miR-200b/c/429 to regulate CHD1 expression

Objectives

Long non‐coding RNA (lncRNA) MATN1‐AS1 is a newfound lncRNA that has been rarely explored in cancers. Herein, we would like to investigate its role in glioma.

Materials and methods

qRT‐PCR was conducted to examine gene expression in glioma. Then, MTT assay, colony formation assay and flow cytometry analysis were applied to evaluate the function of MATN1‐AS1 on glioma cells. Western blot was performed to measure the protein levels of genes. Besides, the luciferase reporter assay, RNA pull‐down assay, RIP assay and Spearman's correlation analysis were also performed as needed.

Results

Firstly, a data from TCGA showed that MATN1‐AS1 might be largely implicated in glioma. Meanwhile, MATN1‐AS1 upregulation confirmed in glioma predicted poor clinical outcomes. Functionally, MATN1‐AS1 knockdown restrained cell proliferation but stimulated apoptosis in vitro and repressed tumour growth in vivo. Mechanistic investigations validated that MATN1‐AS1 functioned as a ceRNA for miR‐200b/c/429 to upregulate CHD1 which was also verified to exert a growth‐promoting role in glioma cells here. Importantly, both CHD1 overexpression and miR‐200b/c/429 inhibition could rescue the obstructive role of MATN1‐AS1 silence in glioma cells.

Conclusions

MATN1‐AS1 promotes glioma progression through regulating miR‐200b/c/429‐CHD1 axis, suggesting MATN1‐AS1 as a probable target for glioma treatment.