miRNA Sponge Research Articles

Circular RNA CDR1as Inhibits the Metastasis of Gastric Cancer through Targeting miR-876-5p/GNG7 Axis.

Circular RNA CDR1as has been demonstrated to participate in various cancer progressions as miRNA sponges. The exact underlying mechanisms of CDR1as on gastric cancer (GC) metastasis remain unknown. Here, we found that CDR1as knockdown facilitated GC cell migration and invasion while its overexpression inhibited the migration and invasion abilities of GC cells in vitro and in vivo. Moreover, epithelial-mesenchymal transition- (EMT-) associated proteins and MMP2 and MMP9 were downregulated by CDR1as. Bioinformatics analysis combined with dual-luciferase reporter gene assays, western blot, RT-qPCR analysis, and functional rescue experiments demonstrated that CDR1as served as a miR-876-5p sponge and upregulated the target gene GNG7 expression to suppress GC metastasis. In summary, our findings indicate that CDR1as suppresses GC metastasis through the CDR1as/miR-876-5p/GNG7 axis.

Characteristics of circular RNAs expression of peripheral blood mononuclear cells in humans with coronary artery disease.

Circular RNAs (circRNAs) function as promising biomarkers and therapeutic targets for coronary artery disease due to their high stability, covalently closed structure, and potential gene regulation. We aimed to identify the expression profile and role of circular RNAs (circRNAs) in coronary artery disease (CAD). We performed RNA sequence analysis of circRNAs in peripheral blood mononuclear cells of five patients with CAD and five controls. Bioinformatics analyses were adopted to explore biological functions of differentially expressed circRNAs. The miRanda and TargetScan tools were used to predict the microRNA (miRNA)-targeting interactions and to construct a triple network of differentially expressed gene-circRNA-miRNA-mRNA. In total, 13,160 downregulated and 12,905 upregulated circRNAs were identified in CAD. A gene ontology annotation analysis showed that genes in the network were involved in organelle organization, cell cycle, mitotic cycle, and cellular metabolic process. Parental genes of the 10 dysregulated circRNAs were involved in metabolism and protein modification, and these circRNAs might regulate gene expression associated with CAD via miRNA sponges. As potential competing endogenous RNAs (ceRNAs), dysregulated circRNAs may be involved in the pathogenesis of CAD, which provides new insights into the diagnosis and prognosis of coronary artery disease.

X-Inactive-Specific Transcript: Review of Its Functions in the Carcinogenesis

X-inactive–specific transcript (XIST) is one of the firstly discovered long non-coding RNAs with prominent roles in the process of X inactivation. Moreover, this transcript contributes in the carcinogenic process in different tissues. In addition to interacting with chromatin modifying molecules, XIST can be served as a molecular sponge for miRNAs to modulate expression of miRNA targets. Most of the studies have indicated an oncogenic role for XIST. However, in prostate cancer, a single study has indicated a tumor suppressor role for this lncRNA. Similar result has been reported for XIST in oral squamous cell carcinoma. In hepatocellular carcinoma, breast cancer, ovarian cancer, osteosarcoma, and renal cell carcinoma, different studies have reported inconsistent results. In the present manuscript, we review function of XIST in the carcinogenesis.

Computational Identification of miRNAs and Temperature-Responsive lncRNAs From Mango (Mangifera indica L.).

Mango is a major tropical fruit in the world and is known as the king of fruits because of its flavor, aroma, taste, and nutritional values. Although various regulatory roles of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) have been investigated in many plants, there is yet an absence of such study in mango. This is the first study to provide information on non-coding RNAs (ncRNAs) of mango with the aims of identifying miRNAs and lncRNAs and discovering their potential functions by interaction prediction of the miRNAs, lncRNAs, and their target genes. In this analysis, about a hundred miRNAs and over 7,000 temperature-responsive lncRNAs were identified and the target genes of these ncRNAs were characterized. According to these results, the newly identified mango ncRNAs, like other plant ncRNAs, have a potential role in biological and metabolic pathways including plant growth and developmental process, pathogen defense mechanism, and stress-responsive process. Moreover, mango lncRNAs can target miRNAs to reduce the stability of lncRNAs and can function as molecular decoys or sponges of miRNAs. This paper would provide information about miRNAs and lncRNAs of mango and would help for further investigation of the specific functions of mango ncRNAs through wet lab experiments.

Integrated analysis of ceRNA network in hepatocellular carcinoma using bioinformatics analysis.

Background:Long noncoding RNAs (lncRNAs) can work as microRNA (miRNA) sponges through a competitive endogenous RNA (ceRNA) mechanism. LncRNAs and miRNAs are important components of competitive endogenous binding, and their expression imbalance in hepatocellular carcinoma (HCC) is closely related to tumor development, diagnosis, and prognosis. This study explored the potential impact of the ceRNA regulatory network in HCC on the prognosis of HCC patients.Methods:We thoroughly researched the differential expression profiles of lncRNAs, miRNAs, and mRNAs from 2 HCC Gene Expression Omnibus datasets (GSE98269 and GSE60502). Then, a dysregulated ceRNA network was constructed by bioinformatics. In addition, hub genes in the ceRNA network were screened by Cytoscape, these hub genes functional analysis was performed by gene set enrichment analysis, and the expression of these hub genes in tumors and their correlation with patient prognosis were verified with Gene Expression Profiling Interactive Analysis.Results:A ceRNA network was successfully constructed in this study including 4 differentially expressed (DE) lncRNAs, 7 DEmiRNAs, and 166 DEmRNAs. Importantly, 4 core genes (CCNA2, CHEK1, FOXM1, and MCM2) that were significantly associated with HCC prognosis were identified.Conclusions:Our study provides comprehensive and meaningful insights into HCC tumorigenesis and the underlying molecular mechanisms of ceRNA. Furthermore, the specific ceRNAs can be further used as potential therapeutic targets and prognostic biomarkers for HCC.

Regulatory Potential of Competing Endogenous RNAs in Myotonic Dystrophies.

Non-coding RNAs (ncRNAs) have been reported to be implicated in cell fate determination and various human diseases. All ncRNA molecules are emerging as key regulators of diverse cellular processes; however, little is known about the regulatory interaction among these various classes of RNAs. It has been proposed that the large-scale regulatory network across the whole transcriptome is mediated by competing endogenous RNA (ceRNA) activity attributed to both protein-coding and ncRNAs. ceRNAs are considered to be natural sponges of miRNAs that can influence the expression and availability of multiple miRNAs and, consequently, the global mRNA and protein levels. In this review, we summarize the current understanding of the role of ncRNAs in two neuromuscular diseases, myotonic dystrophy type 1 and 2 (DM1 and DM2), and the involvement of expanded CUG and CCUG repeat-containing transcripts in miRNA-mediated RNA crosstalk. More specifically, we discuss the possibility that long repeat tracts present in mutant transcripts can be potent miRNA sponges and may affect ceRNA crosstalk in these diseases. Moreover, we highlight practical information related to innovative disease modelling and studying RNA regulatory networks in cells. Extending knowledge of gene regulation by ncRNAs, and of complex regulatory ceRNA networks in DM1 and DM2, will help to address many questions pertinent to pathogenesis and treatment of these disorders; it may also help to better understand general rules of gene expression and to discover new rules of gene control.

Competing Endogenous RNAs in Cervical Carcinogenesis: A New Layer of Complexity

MicroRNAs (miRNAs) regulate gene expression by binding to complementary sequences within target mRNAs. Apart from working ‘solo’, miRNAs may interact in important molecular networks such as competing endogenous RNA (ceRNA) axes. By competing for a limited pool of miRNAs, transcripts such as long noncoding RNAs (lncRNAs) and mRNAs can regulate each other, fine-tuning gene expression. Several ceRNA networks led by different lncRNAs—described here as lncRNA-mediated ceRNAs—seem to play essential roles in cervical cancer (CC). By conducting an extensive search, we summarized networks involved in CC, highlighting the major impacts of such dynamic molecular changes over multiple cellular processes. Through the sponging of distinct miRNAs, some lncRNAs as HOTAIR, MALAT1, NEAT1, OIP5-AS1, and XIST trigger crucial molecular changes, ultimately increasing cell proliferation, migration, invasion, and inhibiting apoptosis. Likewise, several lncRNAs seem to be a sponge for important tumor-suppressive miRNAs (as miR-140-5p, miR-143-3p, miR-148a-3p, and miR-206), impairing such molecules from exerting a negative post-transcriptional regulation over target mRNAs. Curiously, some of the involved mRNAs code for important proteins such as PTEN, ROCK1, and MAPK1, known to modulate cell growth, proliferation, apoptosis, and adhesion in CC. Overall, we highlight important lncRNA-mediated functional interactions occurring in cervical cells and their closely related impact on cervical carcinogenesis.

HOTAIR beyond repression: In protein degradation, inflammation, DNA damage response, and cell signaling

Long noncoding RNAs (lncRNAs) are pervasively transcribed from the mammalian genome as transcripts that are usually >200 nucleotides long. LncRNAs generally do not encode proteins but are involved in a variety of physiological processes, principally as epigenetic regulators. HOX transcript antisense intergenic RNA (HOTAIR) is a well-characterized lncRNA that has been implicated in several cancers and in various other diseases. HOTAIR is a repressor lncRNA and regulates various repressive chromatin modifications. However, recent studies have revealed additional functions of HOTAIR in regulation of protein degradation, microRNA (miRNA) sponging, NF-κB activation, inflammation, immune signaling, and DNA damage response. Herein, we have summarized the diverse functions and modes of action of HOTAIR in protein degradation, inflammation, DNA repair, and diseases, beyond its established functions in gene silencing.

Circ-HACE1 Aggravates Cigarette Smoke Extract-Induced Injury in Human Bronchial Epithelial Cells via Regulating Toll-Like Receptor 4 by Sponging miR-485-3p.

BackgroundSmoking is the most common cause of chronic obstructive pulmonary disease (COPD), and the early diagnosis for COPD remains poor. Exploring the molecular mechanism and finding feasible biomarkers will be beneficial for clinical management of COPD. Circular RNAs (circRNAs) are noncoding RNAs that act as miRNA sponges to regulate the expression levels of genes, leading to the changes of cellular phenotypes and disease progression. CircRNA HECT domain and ankyrin repeat containing E3 ubiquitin protein ligase 1 (circ-HACE1) was abnormally expressed after the induction of cigarette smoke extract (CSE) in cell model. This study was performed to explore its function and mechanism in COPD.MethodsCirc-HACE1, microRNA-485-3p (miR-485-3p) and toll-like receptor 4 (TLR4) detection was performed by quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability and apoptosis/cell cycle were respectively examined using cell counting kit-8 (CCK-8) and flow cytometry. Inflammatory cytokines were determined by enzyme-linked immunosorbent assay (ELISA). Oxidative stress was evaluated through the measurement of malondialdehyde (MDA) and superoxide dismutase (SOD). The target binding analysis was conducted via dual-luciferase reporter assay. Western blot was employed for protein expression detection of TLR4.ResultsCirc-HACE1 was overexpressed in smokers or smokers with COPD and CSE upregulated circ-HACE1 expression in 16HBE cells. Knockdown of circ-HACE1 attenuated CSE-stimulated cell viability and cell cycle repression, as well as the enhancement of cell apoptosis, inflammatory response and oxidative stress. MiR-485-3p was a target of circ-HACE1. Circ-HACE1 regulated CSE-induced cell injury via targeting miR-485-3p. TLR4 was a downstream target of miR-485-3p, and miR-485-3p inhibited the CSE-induced cell damages by directly downregulating the level of TLR4. Circ-HACE1/miR-485-3p regulated TLR4 expression in CSE-treated 16HBE cells, and TLR4 overexpression also reversed all effects of si-circ-HACE1 on CSE-treated 16HBE cells.ConclusionThese findings elucidated that circ-HACE1 contributed to the CSE-induced cell damages in COPD cell models via regulating TLR4 by acting as the sponge of miR-485-3p.

Characterization of the whole transcriptome of spleens from Chinese indigenous breed Ningxiang pig reveals diverse coding and non-coding RNAs for immunity regulation

The spatio-temporal expression patterns of RNA and comparisons between different developmental stages have been one of the useful techniques for studying animal physiology and functional gene regulations. A Chinese indigenous breed Ningxiang pig is known for its quality meat production, disease resistance and slow growth performances in pig industry. To gain a better understanding of pig immunity and disease resistance, we comprehensively analyzed the whole transcriptome of the spleens from three important developmental nodes of Ningxiang pig at 30, 90 and 210 days of age. By three ways of comparisons (30vs 90 days, 30 vs 210 days and 90 vs 210 days), a total of 364to 865 differentially expressed mRNAs, 37 to 98 differentially expressed miRNAs,220 to 278 lncRNAs, and 96 to 113 circRNAs were identified. Further analysis of expression patterns, potential function and interactions with miRNAs identified the potential non-coding RNAs related to immunomodulation such as ssc-miRNA-150, ssc-miRNA-497, MSTRG24160, MSTRG18646. The results revealed that miRNAs and circRNAs may have evolved to regulate a large set of biological processes of spleen function in Ningxiang pigs, and circRNAs play a role of miRNA sponges. The results from study is the first report of whole transcriptome analysis of Ningxiang pig spleen and provide new insights into the expression changes of RNAs during the spleen development, which contribute to the phenotypic formation of immunity and disease resistancesin Chinese indigenous pig breeds.

Circ-RNA Expression Pattern and circ-RNA-miRNA-mRNA Network in The Pathogenesis of Human Intervertebral Disc Degeneration.

ObjectiveThe present study aimed to screen the differentially expressed (DE) circular RNAs (circ-RNAs) between lumbar intervertebral disc degeneration (IVDD) and normal tissues.Material and MethodsIn this experimental study, microarray hybridization was performed to evaluate circ-RNA expression, and the DE circ-RNAs were confirmed by quantitative real-time polymerase chain reaction (qRT-PCR). Host genes of DE circ-RNAs were predicted, and their functions were evaluated. Further, a competitive endogenesis (ce) RNA network among 4 DE circ-RNAs-miRNA-mRNA was constructed by Cytoscape. ResultsA total of 2636 circ-RNAs were detected in all samples; among them, 89.23% were exonic circ-RNAs. There were 138 DE circ-RNAs, including 134 up-regulated circ-RNAs and 4 downregulated circ-RNAs in IVDD samples. qRT-PCR validation experiments showed that expression trends of hsa_circ_0003239, hsa_circ_0003162, hsa_circ_0005918, and hsa_circ_0005556 were in line with the microarray analysis results. Functional enrichment analysis showed that host genes of DE circ-RNAs significantly disturbed pathways of regulation of actin cytoskeleton, propanoate metabolism, and ErbB signaling pathway. The four DE circ-RNAs related ceRNA network was constructed.ConclusionsOur results revealed that circ-RNAs can function as miRNA sponges and regulate parent gene expression to affect IVDD.

Porcine Milk-Derived Small Extracellular Vesicles Promote Intestinal Immunoglobulin Production through pIgR.

Simple SummaryAs the irreplaceable nutrient source for young mammals, milk has a number of biological functions. Milk derived extracellular vesicles are a recently discovered component of milk and have potential regulatory effects on intestinal health and immunity. In this study, in vivo and in vitro experiments were performed to examine the effects of porcine milk small extracellular vesicles (PM-sEVs) on intestinal immunity. As a result, PM-sEVs promoted intestinal secretory immunoglobulin A (SIgA) levels, and increased the expression levels of the polymeric immunoglobulin receptor (pIgR) both in mice and piglet. We identified circ-XPO4 in PM-sEVs as a crucial circRNA, which promotes the expression of pIgR via the suppression of miR-221-5p in the intestinal cell. In conclusion, our research provides a new understanding of the nutritional physiology of porcine milk in intestinal immunity.Secretory immunoglobulin A (SIgA) plays an important role in gut acquired immunity and mucosal homeostasis. Breast milk is the irreplaceable nutritional source for mammals after birth. Current studies have shown the potential functional role of milk-derived small extracellular vesicles (sEVs) and their RNAs cargo in intestinal health and immune regulation. However, there is a lack of studies to demonstrate how milk-derived sEVs affect intestinal immunity in recipient. In this study, through in vivo experiments, we found that porcine milk small extracellular vesicles (PM-sEVs) promoted intestinal SIgA levels, and increased the expression levels of polymeric immunoglobulin receptor (pIgR) both in mice and piglet. We examined the mechanism of how PM-sEVs increased the expression level of pIgR in vitro by using a porcine small intestine epithelial cell line (IPEC-J2). Through bioinformatics analysis, dual-luciferase reporter assays, and overexpression or knockdown of the corresponding non-coding RNAs, we identified circ-XPO4 in PM-sEVs as a crucial circRNA, which leads to the expression of pIgR via the suppression of miR-221-5p in intestinal cells. Importantly, we also observed that oral administration of PM-sEVs increased the level of circ-XPO4 and decreased the level of miR-221-5p in small intestine of piglets, indicating that circRNAs in milk-derived sEVs act as sponge for miRNAs in recipients. This study, for the first time, reveals that PM-sEVs have a capacity to stimulate intestinal SIgA production by delivering circRNAs to receptors and sponging the recipient’s original miRNAs, and also provides valuable data for insight into the role and mechanism of animal milk sEVs in intestinal immunity.

Poly-Adenine-Based Spherical Nucleic Acids for Efficient Live-Cell MicroRNA Capture.

Direct delivery of exogenous non-coding nucleic acids into living cells has attracted intense interest in biological applications. However, the cell entry efficiency and target capture ability remain to be improved. Herein, we report a method for compartmenting the nucleic acids on the surface of poly-adenine-based spherical nucleic acids (polyA-SNAs) for efficient capture of oncogenic microRNAs (miRNAs) in living cells. We find that polyA-SNAs exhibit high cell entry efficiency, which is insensitive to the configuration of the anti-miRNA sequences. By programming the length of polyAs, we precisely engineered the spatial configuration of the anti-miRNA sequences in polyA-SNAs. Compartmentalized polyA-SNAs bind to miRNAs with improved capture ability as compared to densely compacted SNAs. We further demonstrate that polyA-SNAs serve as high-efficacy miRNA sponges for capturing oncogenic miRNAs both in living cells and in mice. The efficient inhibition of miRNAs results in significant suppression of tumor growth.

CircRNA-ceRNA Network Revealing the Potential Regulatory Roles of CircRNA in Alzheimer's Disease Involved the cGMP-PKG Signal Pathway.

Background: Alzheimer’s disease (AD) is a chronic progressive neurodegenerative disease. The characteristic pathologies include extracellular senile plaques formed by β-amyloid protein deposition, neurofibrillary tangles formed by hyperphosphorylation of tau protein, and neuronal loss with glial cell hyperplasia. Circular RNAs (circRNAs) are rich in miRNA-binding sites (miRNA response elements, MREs), which serve as miRNA sponges or competitive endogenous RNAs (ceRNAs). Although several research groups have identified dysregulated circRNAs in the cerebral cortex of SAMP8 mice or APP/PS1 mice using deep RNA-seq analysis, we need to further explore circRNA expression patterns, targets, functions and the signaling pathways involved in the pathogenesis of AD and in particular the hippocampal circRNA expression profiles in AD.Methods: We used deep RNA sequencing to investigate circRNA-ceRNA network patterns in the hippocampus of APP/PS1 mice.Results: In our study, 70 dysregulated circRNAs, 39 dysregulated miRNAs and 121 dysregulated mRNAs were identified between the APP/PS1 group and the wild-type group at 8 months in the hippocampus of the mice. Through correlation analysis, we identified 11 dysregulated circRNAs, 7 dysregulated miRNAs and 8 dysregulated mRNAs forming 16 relationships in the circRNA-miRNA-mRNA regulatory network. Gene ontology (GO) analysis indicated that the dysregulated circRNAs were most enriched in biological metabolic processes. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the dysregulation of circRNAs was enriched in the cGMP-PKG signaling pathway, cAMP signaling pathway, Hippo signaling pathway, platelet activation, long-term potentiation and axon guidance. In addition, our findings preliminarily verified that the novel_circ_0003012/mmu-miR-298-3p/Smoc2 signaling axis may regulate the pathophysiology of AD by affecting the cGMP-PKG signaling pathway.Conclusions: These newly identified circRNAs in networks and signaling pathways reveal potential diagnostic or therapeutic targets for AD.

Poly‐Adenine‐Based Spherical Nucleic Acids for Efficient Live‐Cell MicroRNA Capture

AbstractDirect delivery of exogenous non‐coding nucleic acids into living cells has attracted intense interest in biological applications. However, the cell entry efficiency and target capture ability remain to be improved. Herein, we report a method for compartmenting the nucleic acids on the surface of poly‐adenine‐based spherical nucleic acids (polyA‐SNAs) for efficient capture of oncogenic microRNAs (miRNAs) in living cells. We find that polyA‐SNAs exhibit high cell entry efficiency, which is insensitive to the configuration of the anti‐miRNA sequences. By programming the length of polyAs, we precisely engineered the spatial configuration of the anti‐miRNA sequences in polyA‐SNAs. Compartmentalized polyA‐SNAs bind to miRNAs with improved capture ability as compared to densely compacted SNAs. We further demonstrate that polyA‐SNAs serve as high‐efficacy miRNA sponges for capturing oncogenic miRNAs both in living cells and in mice. The efficient inhibition of miRNAs results in significant suppression of tumor growth.

Identifying an lncRNA-Related ceRNA Network to Reveal Novel Targets for a Cutaneous Squamous Cell Carcinoma

Simple SummaryThe exact functions and molecular mechanism of lncRNAs, acting as competitive endogenous RNAs in a cutaneous squamous cell carcinoma, remain unexplored. The present study was conducted to identify the differentially expressed lncRNAs and mRNAs and establish the lncRNA-related competing endogenous RNA networks associated with a cutaneous squamous cell carcinoma. A competing endogenous RNA network consisting of 137 miRNA-lncRNA and 221 miRNA-mRNA pairs was constructed. As for the functional analysis of the mRNAs in the network, a FoxO signaling pathway, an autophagy and cellular senescence were the top enrichment terms based on the Kyoto Encyclopedia of Genes and Genomes analysis. We identified five core mRNAs and built a core mRNA-associated competing endogenous RNA network. Finally, one lncRNA HLA-F-AS1 and three mRNAs named AGO4, E2F1 and CCND1 in the core mRNA-associated competing endogenous RNA network were validated with the same expression patterns. The core mRNAs and their associated lncRNAs may provide potential therapeutic targets for cutaneous squamous cell carcinomas.A cutaneous squamous cell carcinoma (cSCC) derived from keratinocytes is the second most common cause of non-melanoma skin cancer. The accumulation of the mutational burden of genes and cellular DNA damage caused by the risk factors (e.g., exposure to ultraviolet radiation) contribute to the aberrant proliferation of keratinocytes and the formation of a cSCC. A cSCC encompasses a spectrum of diseases that range from recursor actinic keratosis (AK) and squamous cell carcinoma (SCC) in situ (SCCIS) to invasive cSCCs and further metastatic SCCs. Emerging evidence has revealed that lncRNAs are involved in the biological process of a cSCC. According to the ceRNA regulatory theory, lncRNAs act as natural miRNA sponges and interact with miRNA response elements, thereby regulating the mRNA expression of their down-stream targets. This study was designed to search for the potential lncRNAs that may become potential therapeutic targets or biomarkers of a cSCC. Considering the spirit of the study to be adequately justified, we collected microarray-based datasets of 19 cSCC tissues and 12 normal skin samples from the GEO database (GSE42677 and GSE45164). After screening the differentially expressed genes via a limma package, we identified 24 differentially expressed lncRNAs (DElncRNAs) and 3221 differentially expressed mRNAs (DEmRNAs). The miRcode, miRTarBase, miRDB and TargetScan databases were used to predict miRNAs that could interact with DElncRNAs and DEmRNAs. A total of 137 miRNA-lncRNA and 221 miRNA-mRNA pairs were retained in the ceRNA network, consisting of 31 miRNAs, 11 DElncRNAs and 155 DEmRNAs. For the functional analysis, the top enriched biological process was enhancer sequence-specific DNA binding in Gene Ontology (GO) terms. The FoxO signaling pathway, autophagy and cellular senescence were the top enrichment terms based on a Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. The combination of a STRING tool and Cytoscape software (plug-in MCODE) identified five core mRNAs and built a core mRNA-associated ceRNA network. The expression for five identified core mRNAs and their related nine lncRNAs was validated using the external dataset GSE7553. Finally, one lncRNA HLA-F-AS1 and three mRNAs named AGO4, E2F1 and CCND1 were validated with the same expression patterns. We speculate that lncRNA HLA-F-AS1 may sponge miR-17-5p or miR-20b-5p to regulate the expression of CCND1 and E2F1 in the cSCC. The present study may provide potential diagnostic and therapeutic targets for cSCC patients.

Warburg effect-promoted exosomal circ_0072083 releasing up-regulates NANGO expression through multiple pathways and enhances temozolomide resistance in glioma

BackgroundTemozolomide (TMZ) resistance limits its application in glioma. Exosome can carry circular RNAs (circRNAs) to regulate drug resistance via sponging microRNAs (miRNAs). miRNAs can control mRNA expression by regulate the interaction with 3’UTR and methylation. Nanog homeobox (NANOG) is an important biomarker for TMZ resistance. Hitherto, it is unknown about the role of exosomal hsa_circ_0072083 (circ_0072083) in TMZ resistance in glioma, and whether it is associated with NANOG via regulating miRNA sponge and methylation.MethodsTMZ-resistant (n = 36) and sensitive (n = 33) patients were recruited. The sensitive cells and constructed resistant cells were cultured and exposed to TMZ. circ_0072083, miR-1252-5p, AlkB homolog H5 (ALKBH5) and NANOG levels were examined via quantitative reverse transcription polymerase chain reaction and western blot. The half maximal inhibitory concentration (IC50) of TMZ, cell proliferation, apoptosis, migration and invasion were analyzed via Cell Counting Kit-8, colony formation, flow cytometry, wound healing and transwell assays. The in vivo function was assessed using xenograft model. The N6-methyladenosine (m6A) level was analyzed via methylated RNA immunoprecipitation (MeRIP). Target relationship was investigated via dual-luciferase reporter assay and RNA immunoprecipitation. Warburg effect was investigated via lactate production, glucose uptake and key enzymes expression. Exosome was isolated and confirmed via transmission electron microscopy and specific protein expression.Resultscirc_0072083 expression was increased in TMZ-resistant glioma tissues and cells. circ_0072083 knockdown restrained the resistance of resistant cells via decreasing IC50 of TMZ, proliferation, migration, invasion and xenograft tumor growth and increasing apoptosis. circ_0072083 silence reduced NANOG expression via blocking ALKBH5-mediated demethylation. circ_0072083 could regulate NANOG and ALKBH5 via targeting miR-1252-5p to control TMZ resistance. Warburg effect promoted the release of exosomal circ_0072083 in resistant cells. Exosomal circ_0072083 from resistant cells increased the resistance of sensitive cells to TMZ in vitro and xenograft model. Exosomal circ_0072083 level was enhanced in resistant patients, and it had a diagnostic value and indicated a lower overall survival in glioma.ConclusionExosomal circ_0072083 promoted TMZ resistance via increasing NANOG via regulating miR-1252-5p-mediated degradation and demethylation in glioma.

Transcriptome Profiling Reveals the Endogenous Sponging Role of LINC00659 and UST-AS1 in High-Altitude Induced Thrombosis.

The pathophysiology of deep vein thrombosis (DVT) is considered as multifactorial, where thrombus formation is an interplay of genetic and acquired risk factors. Little is known about the expression profile and roles of long noncoding RNAs (lncRNAs) in human subjects developing DVT at high altitude. Using RNAseQ, we compared peripheral blood mRNA and lncRNA expression profile in human high-altitude DVT (HA-DVT) patients with high-altitude control subjects. We used DESeq to identify differentially expressed (DE) genes. We annotated the lncRNAs using NONCODE 3.0 database. In silico putative lncRNA-miRNA association study unravels the endogenous miRNA sponge associated with our candidate lncRNAs. These findings were validated by small-interfering RNA (siRNA) knockdown assay of the candidate lncRNAs conducted in primary endothelial cells. We identified 1,524 DE mRNAs and 973 DE lncRNAs. Co-expressed protein-coding gene analysis resulted in a list of 722 co-expressed protein-coding genes with a Pearson correlation coefficients >0.7. The functional annotation of co-expressed genes and putative proteins revealed their involvement in the hypoxia, immune response, and coagulation cascade. Through its miRNA response elements to compete for miR-143 and miR-15, lncRNA-LINC00659 and UXT-AS1 regulate the expression of prothrombotic genes. Furthermore, in vitro RNA interference (siRNA) simultaneously suppressed lncRNAs and target gene mRNA level. This transcriptome profile describes novel potential mechanisms of interaction between lncRNAs, the coding genes, miRNAs, and regulatory transcription factors that define the thrombotic signature and may be used in establishing lncRNAs as a biomarker in HA-DVT.

Identification of an immune signature to predict poor clinical outcome in cervical cancer.

Aim: To explore tumor immune microenvironment and identify immune prognostic-related circRNAs in cervical cancer. Materials & methods: RNA-seq in combination with bioinformatics were performed to establish a prognostic risk model and a circRNAs-miRNAs-CXCL8 network. Results: High-risk group correlated with poor survival outcome, and had lower PD-1 immunogenicity. Additionally, CXCL8 could distinguish normal tissue, low- and high-risk tumor tissues, the expression of which showed an increasing trend among the three groups. RNA-seq and bioinformatics indicated that circRNAs like hsa_circ_0025721 might upregulate CXCL8 through sponging miRNAs including hsa-miR-4428. Conclusion: We constructed an immune risk model related with CD8 T cells to predict the cervical cancer patients' prognosis and explored the abnormal expression mechanism of CXCL8 through the ceRNA mechanism.

Hypoxia-Induced MALAT1 Promotes the Proliferation and Migration of Breast Cancer Cells by Sponging MiR-3064-5p.

Hypoxia, a common process during tumor growth, can lead to tumor aggressiveness and is tightly associated with poor prognosis. Long noncoding RNAs (lncRNAs) are long ribonucleotides (>200 bases) with limited ability to translate proteins, and are known to affect many aspects of cellular function. One of their regulatory mechanisms is to function as a sponge for microRNA (miRNA) to modulate its biological functions. Previously, MALAT1 was identified as a hypoxia-induced lncRNA. However, the regulatory mechanism and functions of MALAT1 in breast cancer are still unclear. Therefore, we explored whether MALAT1 can regulate the functions of breast cancer cells through miRNAs. Our results showed the expression levels of MALAT1 were significantly up-regulated under hypoxia and regulated by HIF-1α and HIF-2α. Next, in contrast to previous reports, nuclear and cytoplasmic fractionation assays and fluorescence in situ hybridization indicated that MALAT1 was mainly located in the cytoplasm. Therefore, the labeling of MALAT1 as a nuclear marker should be done with the caveat. Furthermore, expression levels of miRNAs and RNA immunoprecipitation using antibody against AGO2 showed that MALAT1 functioned as a sponge of miRNA miR-3064-5p. Lastly, functional assays revealed that MALAT1 could promote cellular migration and proliferation of breast cancer cells. Our findings provide evidence that hypoxia-responsive long non-coding MALAT1 could be transcriptionally activated by HIF-1α and HIF-2α, act as a miRNA sponge of miR-3064-5p, and promote tumor growth and migration in breast cancer cells. These data suggest that MALAT1 may be a candidate for therapeutic targeting of breast cancer progression.