CARL lncRNA inhibits anoxia-induced mitochondrial fission and apoptosis in cardiomyocytes by impairing miR-539-dependent PHB2 downregulation

Long noncoding RNAs (LncRNAs) - The dawning of a new treatment for cardiac hypertrophy and heart failure

Long noncoding RNAs (lncRNAs) represent a category of noncoding RNAs with the potential for genetic and epigenetic regulations. As important regulators of gene expression, increasing evidence has proven that lncRNAs play a significant regulatory role in various cardiovascular pathologies. In particular, lncRNAs have been proved to be participating in gene regulatory mechanisms involved in heart growth and development that can be exploited to repair the injured adult heart. Furthermore, lncRNAs have been revealed as possible therapeutic targets for heart failure with different causes and in different stages. In the journey from a healthy heart to heart failure, lncRNAs have been shown to participate in almost every landmark of heart failure pathogenesis including ischemic injury, cardiac hypertrophy, and cardiac fibrosis. Furthermore, the manipulation of lncRNAs palliates the progression of heart failure by attenuating ischemic heart injury, cardiac hypertrophy and cardiac fibrosis, as well as facilitating heart regeneration and therapeutic angiogenesis. This review will highlight recent updates regarding the involvement of lncRNAs in cardiac hypertrophy and heart failure and their potential as novel therapeutic targets. This article is part of a Special Issue entitled: Genetic and epigenetic control of heart failure - edited by Jun Ren & Megan Yingmei Zhang.

MIAT Is a Pro-fibrotic Long Non-coding RNA Governing Cardiac Fibrosis in Post-infarct Myocardium

A long non-coding RNA (lncRNA), named myocardial infarction associated transcript (MIAT), has been documented to confer risk of myocardial infarction (MI). The aim of this study is to elucidate the pathophysiological role of MIAT in regulation of cardiac fibrosis. In a mouse model of MI, we found that MIAT was remarkably up-regulated, which was accompanied by cardiac interstitial fibrosis. MIAT up-regulation in MI was accompanied by deregulation of some fibrosis-related regulators: down-regulation of miR-24 and up-regulation of Furin and TGF-β1. Most notably, knockdown of endogenous MIAT by its siRNA reduced cardiac fibrosis and improved cardiac function and restored the deregulated expression of the fibrosis-related regulators. In cardiac fibroblasts treated with serum or angiotensin II, similar up-regulation of MIAT and down-regulation of miR-24 were consistently observed. These changes promoted fibroblasts proliferation and collagen accumulation, whereas knockdown of MIAT by siRNA or overexpression of miR-24 with its mimic abrogated the fibrogenesis. Our study therefore has identified MIAT as the first pro-fibrotic lncRNA in heart and unraveled the role of MIAT in the pathogenesis of MI. These findings also promise that normalization of MIAT level may prove to be a therapeutic option for the treatment of MI-induced cardiac fibrosis and the associated cardiac dysfunction.

LncRNA HULC triggers autophagy via stabilizing Sirt1 and attenuates the chemosensitivity of HCC cells

Considerable evidences have shown that autophagy has an important role in tumor chemoresistance. However, it is still unknown whether the lncRNA HULC (highly upregulated in liver cancer) is involved in autophagy and chemoresistance of hepatocellular carcinoma (HCC). In this study, we for the first time demonstrated that treatment with antitumor reagents such as oxaliplatin, 5-fluorouracil and pirarubicin (THP) dramatically induced HULC expression and protective autophagy. Silencing of HULC sensitized HCC cells to the three antitumor reagents via inhibiting protective autophagy. Ectopic expression of HULC elicited the autophagy of HCC cells through stabilizing silent information regulator 1 (Sirt1) protein. The investigation for the corresponding mechanism by which HULC stabilized Sirt1 revealed that HULC upregulated ubiquitin-specific peptidase 22 (USP22), leading to the decrease of ubiquitin-mediated degradation of Sirt1 protein by removing the conjugated polyubiquitin chains from Sirt1. Moreover, we found that miR-6825-5p, miR-6845-5p and miR-6886-3p could decrease the level of USP22 protein by binding to the 3'-untranlated region of USP22 mRNA. All the three microRNAs (miRNAs) were downregulated by HULC, which resulted in the elevation of USP22. In addition, we showed that the level of HULC was positively correlated with that of Sirt1 protein in human HCC tissues. Collectively, our data reveals that the pathway 'HULC/USP22/Sirt1/ protective autophagy' attenuates the sensitivity of HCC cells to chemotherapeutic agents, suggesting that this pathway may be a novel target for developing sensitizing strategy to HCC chemotherapy.

Identification of miRNA, lncRNA and mRNA-associated ceRNA networks and potential biomarker for MELAS with mitochondrial DNA A3243G mutation

Researchers in the field of mitochondrial biology are increasingly unveiling of the complex mechanisms between mitochondrial dysfunction and noncoding RNAs (ncRNAs). However, roles of ncRNAs underlying mitochondrial myopathy remain unexplored. The aim of this study was to elucidate the regulating networks of dysregulated ncRNAs in Mitochondrial myopathy, Encephalopathy, Lactic Acidosis, and Stroke-like episodes (MELAS) with mitochondrial DNA (mtDNA) A3243G mutation, which might make contributions to the unveiling of the complex mechanisms underlying mitochondrial myopathy and, possibly, new tools applicable to clinical practice. Through high-throughput technology followed by quantitative real-time polymerase chain reaction (qRT-PCR) and bioinformatics analyses, for the first time, we found that the dysregulated muscle miRNAs and lncRNAs between 20 MELAS patients with mtDNA A3243G mutation and 20 controls formed complex regulation networks and participated in immune system, signal transduction, translation, muscle contraction and other pathways in discovery and training phase. Then, selected ncRNAs were validated in muscle and serum in independent validation cohorts by qRT-PCR. Finally, ROC curve analysis indicated reduced serum miR-27b-3p had the better diagnosis value than lactate and might serve as a novel, noninvasive biomarker for MELAS. Follow-up investigation is warranted to better understand roles of ncRNAs in mitochondrial myopathy pathogenesis.

Long non-coding RNA MALAT1 functions as a mediator in cardioprotective effects of fentanyl in myocardial ischemia-reperfusion injury

Long non-coding (lncRNA) MALAT1 can be increased by hypoxia or ischemic limbs. Also, downregulation of MALAT1 contributes to reduction of cardiomyocyte apoptosis. However, the functional involvement of MALAT1 in myocardial ischemia-reperfusion (I/R) injury has not been defined. This study investigated the functional involvement of lncRNA-MALAT1 in cardioprotective effects of fentanyl. HL-1, a cardiac muscle cell line from the AT-1 mouse atrial cardiomyocyte tumor lineage was pre-treated with fentanyl and generated cell model of hypoxia-reoxygenation (H/R). Relative expression of MALAT1, miR-145, and Bnip3 mRNA in cells was determined by quantitative real-time PCR. Cardiomyocyte H/R injury was indicated by lactate dehydrogenase (LDH) release and cell apoptosis. The results showed that fentanyl abrogates expression of responsive gene for H/R and induces downregulation of MALAT1 and Bnip3 and upregulation of miR-145. We found that miR-145/Bnip3 pathway was negatively regulated by MALAT1 in H/R-HL-1 cell with or without fentanyl treatment. Moreover, both MALAT1 overexpression and miR-145 knockdown reverse cardioprotective effects of fentanyl, as indicated by increase in LDH release and cell apoptosis. The reversal effect of MALAT1 for fentanyl is confirmed in cardiac ischemia/reperfusion (I/R) mice. In summary, lncRNA-MALAT1 is sensitive to H/R injury and abrogates cardioprotective effects of Fentanyl by negatively regulating miR-145/Bnip3 pathway.

miR-539 as a key negative regulator of the MEK pathway in myocardial infarction

BACKGROUND

Myocardial infarction is one of the most common causes of death, and the number of individuals at risk is increasing. A rapid and accurate differential diagnosis of myocardial infarction is crucial for timely interventions and for improvement of the prognosis. However, it is difficult to achieve using current methods. To better manage this condition, improved tools for risk prediction, including more accurate biomarkers, are needed.

METHODS

We studied the expression of microRNA-539 (miR-539) and of MEK protein using a rat model of myocardial infarction.

RESULTS

The results of our experiments demonstrated an increase in the expression of miR-539 and a decrease in the expression of MEK. Furthermore, we observed that miR-539 inhibited the expression of MEK through targeting of the 3'UTR of MEK; this led not only to suppressed proliferation but also to apoptosis and autophagy of H9C2 cells.

CONCLUSION

Overexpression of miR-539 plays a role in the degree of myocardial infarction. On the basis of our results, we conclude that miR-539 may be a potential therapeutic target for myocardial infarction.

Regulatory non-coding RNAs in acute myocardial infarction

Acute myocardial infarction (AMI) is one of the most common cardiovascular diseases that leads to high mortality and morbidity globally. Various therapeutic targets for AMI have been investigated in recent years, including the non‐coding RNAs (ncRNAs). NcRNAs, a class of RNA molecules that typically do not code proteins, are divided into several subgroups. Among them, microRNAs (miRNAs) are widely studied for their modulation of several pathological aspects of AMI, including cardiomyocyte apoptosis, inflammation, angiogenesis and fibrosis. It has emerged that long ncRNAs (lncRNAs) and circular RNAs (circRNAs) also regulate these processes via interesting mechanisms. However, the regulatory functions of ncRNAs in AMI and their underlying functional mechanisms have not been systematically described. In this review, we summarize the recent findings involving ncRNA actions in AMI and briefly describe the novel mechanisms of these ncRNAs, highlighting their potential application as therapeutic targets in AMI.

A lncRNA Perspective into (Re)Building the Heart

Our conception of the human genome, long focused on the 2% that codes for proteins, has profoundly changed since its first draft assembly in 2001. Since then, an unanticipatedly expansive functionality and convolution has been attributed to the majority of the genome that is transcribed in a cell-type/context-specific manner into transcripts with no apparent protein coding ability. While the majority of these transcripts, currently annotated as long non-coding RNAs (lncRNAs), are functionally uncharacterized, their prominent role in embryonic development and tissue homeostasis, especially in the context of the heart, is emerging. In this review, we summarize and discuss the latest advances in understanding the relevance of lncRNAs in (re)building the heart.

Long Noncoding RNAs in Cardiovascular Pathology, Diagnosis, and Therapy

Vast parts of mammalian genomes encode for transcripts that are not further translated into proteins. The purpose of the majority of such noncoding ribonucleic acids (RNAs) remained paradoxical for a long time. However, a growing body of evidence demonstrates that long noncoding RNAs are dynamically expressed in different cell types, diseases, or developmental stages to execute a wide variety of regulatory roles at virtually every step of gene expression and translation. Indeed, long noncoding RNAs influence gene expression via epigenetic modulations, through regulating alternative splicing, or by acting as molecular sponges. The abundance of long noncoding RNAs in the cardiovascular system indicates that they may be part of a complex regulatory network governing physiology and pathology of the heart. In this review, we discuss the multifaceted functions of long noncoding RNAs and highlight the current literature with an emphasis on cardiac development and disease. Furthermore, as the enormous spectrum of long noncoding RNAs potentially opens up new avenues for diagnosis and prevention of heart failure, we ultimately evaluate the futuristic prospects of long noncoding RNAs as biomarkers, and therapeutic targets for the treatment of cardiovascular disorders, as well.

Long non-coding RNAs (lncRNAs) in skeletal and cardiac muscle: potential therapeutic and diagnostic targets?

The recent discovery that thousands of RNAs are transcribed by the cell but are never translated into protein, highlights a significant void in our current understanding of how transcriptional networks regulate cellular function. This is particularly astounding when we consider that over 75% of the human genome is transcribed into RNA, but only approximately 2% of RNA is translated into known proteins. This raises the question as to what function the other so-called ‘non-coding RNAs’ (ncRNAs) are performing in the cell. Over the last decade, an enormous amount of research has identified several classes of ncRNAs, predominantly short ncRNAs (<200 nt) that have been confirmed to have functional significance. Recent advances in sequencing technology and bioinformatics have also allowed for the identification of a novel class of ncRNAs, termed long ncRNA (lncRNA) (>200 nt). Several studies have recently shown that long non-coding RNAs (lncRNAs) are associated with tissue development and disease, particularly in cell types that undergo differentiation such as stem cells, cancer cells and striated muscle (skeletal/cardiac). Therefore, understanding the function of these lncRNAs and designing strategies to detect and manipulate them, may present novel therapeutic and diagnostic opportunities. This review will explore the current literature on lncRNAs in skeletal and cardiac muscle and discuss their recent implication in development and disease. Lastly, we will also explore the possibility of using lncRNAs as therapeutic and diagnostic tools and discuss the opportunities and potential shortcomings to these applications.

Long non-coding RNA UCA1 contributes to the progression of oral squamous cell carcinoma by regulating the WNT/β-catenin signaling pathway

With the development of functional genomics studies, a mass of long non-coding RNAs (LncRNA) were discovered from the human genome. Long non-coding RNAs serve as pivotal regulators of genes that are able to generate LncRNA-binding protein complexes to modulate a great number of genes. Recently, the LncRNA urothelial carcinoma-associated 1 (UCA1) has been revealed to be dysregulated, which plays a critical role in the development of a few cancers. However, the role of the biology and clinical significance of UCA1 in the tumorigenesis of oral squamous cell carcinoma (OSCC) remain unknown. We found that UCA1 expression levels were upregulated aberrantly in tongue squamous cell carcinoma tissues and associated with lymph node metastasis and TNM stage. We explored the expression, function, and molecular mechanism of LncRNA UCA1 in OSCC. In the present work, we revealed that UCA1 silencing suppressed proliferation and metastasis and induced apoptosis of OSCC cell lines in vitro and in vivo, which might be related to the activation level of the WNT/β-catenin signaling pathway. Our research results emphasize the pivotal role of UCA1 in the oncogenesis of OSCC and reveal a novel LncRNA UCA1-β-catenin-WNT signaling pathway regulatory network that could contribute to our understanding in the pathogenesis of OSCC and assist in the discovery of a viable LncRNA-directed diagnostic and therapeutic strategy for this fatal disease.

The double life of cardiac mesenchymal cells: Epimetabolic sensors and therapeutic assets for heart regeneration

Organ-specific mesenchymal cells naturally reside in the stroma, where they are exposed to some environmental variables affecting their biology and functions. Risk factors such as diabetes or aging influence their adaptive response. In these cases, permanent epigenetic modifications may be introduced in the cells with important consequences on their local homeostatic activity and therapeutic potential. Numerous results suggest that mesenchymal cells, virtually present in every organ, may contribute to tissue regeneration mostly by paracrine mechanisms. Intriguingly, the heart is emerging as a source of different cells, including pericytes, cardiac progenitors, and cardiac fibroblasts. According to phenotypic, functional, and molecular criteria, these should be classified as mesenchymal cells. Not surprisingly, in recent years, the attention on these cells as therapeutic tools has grown exponentially, although only very preliminary data have been obtained in clinical trials to date. In this review, we summarized the state of the art about the phenotypic features, functions, regenerative properties, and clinical applicability of mesenchymal cells, with a particular focus on those of cardiac origin.

microRNA-539 suppresses tumor growth and tumorigenesis and overcomes arsenic trioxide resistance in hepatocellular carcinoma

AIMS

Dysregulation of microRNAs (miRNAs) plays a critical role in tumor growth and progression. In this study, we sought to explore the expression and biological roles of miR-539 in hepatocellular carcinoma (HCC).

MAIN METHODS

The expression of miR-539 in human HCC tissues and cell lines was examined. The effects of miR-539 overexpression on cell growth, tumorigenicity, arsenic trioxide resistance of HCC cells were determined. The signaling pathways involved in the action of miR-539 in HCC were also investigated.

KEY FINDINGS

miR-539 was downregulated in HCC tissues and cells, relative to corresponding controls. Overexpression of miR-539 inhibited HCC cell viability and colony formation in vitro and impaired tumorigenesis of HCC cells in vivo. Transfection with miR-539 mimic significantly induced apoptosis in HepG2 cells, which was coupled with reduced expression of anti-apoptotic proteins Bcl-2 and Bcl-xL and decreased phosphorylation of Stat3. Overexpression of a constitutively active form of Stat3 partially blocked miR-539-mediated apoptosis. Enforced expression of miR-539 resensitized arsenic trioxide-resistant HCC cells to arsenic trioxide. Intratumoral delivery of miR-539 mimic significantly retarded the growth of xenograft tumors from arsenic trioxide-resistant HCC cells by about 35%, compared to delivery of control miRNA (P<0.05). In combination with arsenic trioxide, miR-539 mimic yielded about 80% decrease in tumor burden.

SIGNIFICANCE

miR-539 functions as a tumor suppressor in HCC and reexpression of this miRNA offers a potential therapeutic strategy for this disease.

Long non-coding RNA TUG1 contributes to tumorigenesis of human osteosarcoma by sponging miR-9-5p and regulating POU2F1 expression

Recent studies have shown that long non-coding RNAs (lncRNAs) have critical roles in tumorigenesis, including osteosarcoma. The lncRNA taurine-upregulated gene 1 (TUG1) was reported to be involved in the progression of osteosarcoma. Here, we investigated the role of TUG1 in osteosarcoma cells and the underlying mechanism. TUG1 expression was measured in osteosarcoma cell lines and human normal osteoblast cells by quantitative real-time PCR (qRT-PCR). The effects of TUG1 on osteosarcoma cells were studied by RNA interference in vitro and in vivo. The mechanism of competing endogenous RNA (ceRNA) was determined using bioinformatic analysis and luciferase assays. Our data showed that TUG1 knockdown inhibited cell proliferation and colony formation, and induced G0/G1 cell cycle arrest and apoptosis in vitro, and suppressed tumor growth in vivo. Besides, we found that TUG1 acted as an endogenous sponge to directly bind to miR-9-5p and downregulated miR-9-5p expression. Moreover, TUG1 overturned the effect of miR-9-5p on the proliferation, colony formation, cell cycle arrest, and apoptosis in osteosarcoma cells, which involved the derepression of POU class 2 homeobox 1 (POU2F1) expression. In conclusion, our study elucidated a novel TUG1/miR-9-5p/POU2F1 pathway, in which TUG1 acted as a ceRNA by sponging miR-9-5p, leading to downregulation of POU2F1 and facilitating the tumorigenesis of osteosarcoma. These findings may contribute to the lncRNA-targeted therapy for human osteosarcoma.

The Role of MicroRNA and LncRNA–MicroRNA Interactions in Regulating Ischemic Heart Disease

Approximately 2% of the human genome consists of protein-coding regions. Therefore, the majority of transcripts are noncoding RNAs, such as microRNA (miRNA) and long noncoding RNAs (lncRNAs). In ischemic heart disease, the majority of miRNAs are repressors or destabilizers of target messenger RNAs. The lncRNAs are a second class of noncoding RNAs that have recently gained attention for their roles in heart disease and in regulating the functions of miRNA. In this review, we summarize the role of miRNA in pathological cardiac hypertrophy and myocardial infarction. In addition, we discuss the functional interactions of miRNA and lncRNA and its impact on these ischemic heart diseases.

AK048794 maintains the mouse embryonic stem cell pluripotency by functioning as an miRNA sponge for miR-592

MiR-592 has been identified as a neural-enriched microRNA, plays an important role in mNPCs differentiation, could induce astrogliogenesis differentiation arrest or/and enhance neurogenesis in vitro Previous studies showed that long noncoding RNAs (lncRNAs) were involved in the neuronal development and activity. To investigate the role of miR-592 in neurogenesis, we described the expression profile of lncRNAs in miR-592 knockout mouse embryonic stem cells (mESCs) and the corresponding normal mESCs by microarray. By the microarray analysis and luciferase reporter assays, we demonstrated that lncRNA - AK048794, regulated by transcription factor GATA1, functioned as a competing endogenous RNA (ceRNA) for miR-592 and led to the de-repression of its endogenous target FAM91A1, which is involved in mESC pluripotency maintenance. Taken together, these observations imply that AK048794 modulated the expression of multiple genes involved in mESC pluripotency maintenance by acting as a ceRNA for miR-592, which may build up the link between the regulatory miRNA network and mESC pluripotency.

The mitochondrial ubiquitin ligase plays an anti-apoptotic role in cardiomyocytes by regulating mitochondrial fission

Apoptosis plays a critical role in the development of myocardial infarction. Cardiomyocytes are enriched with mitochondria and excessive mitochondrial fission can trigger cellular apoptosis. Recently, the mitochondrial ubiquitin ligase (MITOL), localized in the mitochondrial outer membrane, was reported to play an important role in the regulation of mitochondrial dynamics and apoptosis. However, the underlying mechanism of its action remains uncertain. The present study was aimed at uncovering the role of MITOL in the regulation of cardiomyocyte apoptosis. Our results showed that MITOL expression was up-regulated in cardiomyocytes in response to apoptotic stimulation. Mitochondrial ubiquitin ligase overexpression blocked dynamin-related protein 1 accumulation in the mitochondria, and attenuated the mitochondrial fission induced by hydrogen peroxide. Conversely, MITOL knockdown sensitized cardiomyocytes to undergo mitochondrial fission, resulting in subsequent apoptosis. These findings suggest that MITOL plays a protective role against apoptosis in cardiomyocytes, and may serve as a potential therapeutic target for apoptosis-related cardiac diseases.

The lncRNA MALAT1 functions as a competing endogenous RNA to regulate MCL-1 expression by sponging miR-363-3p in gallbladder cancer

Gallbladder carcinoma (GBC) is an aggressive neoplasm, and the treatment options for advanced GBC are limited. Recently, long non‐coding RNAs (lncRNAs) have emerged as new gene regulators and prognostic markers in several cancers. In this study, we found that metastasis‐associated lung adenocarcinoma transcript 1 (MALAT1) expression was up‐regulated in GBC tissues (P < 0.05). Luciferase reporter assays and RNA pull down assays showed that MALAT1 is a target of miR‐363‐3p. Real‐time quantitative PCR and Western blot analysis indicated that MALAT1 regulated Myeloid cell leukaemia‐1 (MCL‐1) expression as a competing endogenous RNA (ceRNA) for miR‐363‐3p in GBC cells. Furthermore, MALAT1 silencing decreased GBC cell proliferation and the S phase cell population and induced apoptosis in vitro. In vivo, tumour volumes were significantly decreased in the MALAT1 silencing group compared with those in the control group. These data demonstrated that the MALAT1/miR‐363‐3p/MCL‐1 regulatory pathway controls the progression of GBC. Inhibition of MALAT1 expression may be to a novel therapeutic strategy for gallbladder cancer.

Long non-coding RNA taurine upregulated 1 enhances tumor-induced angiogenesis through inhibiting microRNA-299 in human glioblastoma

Angiogenesis is one of the critical biological elements affecting the development and progression of cancer. Long non-coding RNAs (lncRNAs) are important regulators and aberrantly expressed in various types of human cancer. Our previous studies indicated that lncRNA taurine upregulated 1 (TUG1) implicated in the regulation of blood-tumor barrier permeability; however, its role in glioblastoma angiogenesis still unclear. Here we demonstrated that TUG1 was up-expressed in human glioblastoma tissues and glioblastoma cell lines. Knockdown of TUG1 remarkably suppressed tumor-induced endothelial cell proliferation, migration and tube formation as well as reducing spheroid-based angiogenesis ability in vitro, which are the critical steps for tumor angiogenesis. Besides, knockdown of TUG1 significantly increased the expression of mircroRNA-299 (miR-299), which was down-expressed in glioblastoma tissues and glioblastoma cell lines. Bioinformatics analysis and luciferase reporter assay revealed that TUG1 influenced tumor angiogenesis via directly binding to the miR-299 and there was a reciprocal repression between TUG1 and miR-299 in the same RNA-induced silencing complex. Moreover, knockdown of TUG1 reduced the expression of vascular endothelial growth factor A (VEGFA), which was defined as a functional downstream target of miR-299. In addition, knockdown of TUG1, shown in the in vivo studies, has effects on suppressing tumor growth, reducing tumor microvessel density and decreasing the VEGFA expression by upregulating miR-299 in xenograft glioblastoma model. Overall, the results demonstrated that TUG1 enhances tumor-induced angiogenesis and VEGF expression through inhibiting miR-299. Also, the inhibition of TUG1 could provide a novel therapeutic target for glioblastoma treatment.

Genome-wide identification and functional analysis of long noncoding RNAs involved in the response to graphene oxide

Long noncoding RNAs (lncRNAs), which are defined as noncoding RNAs having at least 200 nucleotides, can potentially regulate various biological processes. However, the roles of lncRNAs in regulating cellular response to engineered nanomaterials (ENMs) are still unclear. Using Hiseq 2000 sequencing technique, we performed a genome-wide screen to identify lncRNAs involved in the control of toxicity of graphene oxide (GO) using in vivo Caenorhabditis elegans assay system. HiSeq 2000 sequencing, followed by quantitative analysis, identified only 34 dysregulated lncRNAs in GO exposed nematodes. Bioinformatics analysis implies the biological processes and signaling pathways mediated by candidate lncRNAs involved in the control of GO toxicity. A lncRNAs-miRNAs network possibly involved in the control of GO toxicity was further raised. Moreover, we identified the shared lncRNAs based on the molecular regulation basis for chemical surface modifications and/or genetic mutations in reducing GO toxicity. We further provide direct evidence that these shared lncRNAs, linc-37 and linc-14, were involved in the control of chemical surface modifications and genetic mutations in reducing GO toxicity. linc-37 binding to transcriptional factor FOXO/DAF-16 might be important for the control of GO toxicity. Our whole-genome identification and functional analysis of lncRNAs highlights the important roles of lncRNAs based molecular mechanisms for cellular responses to ENMs in organisms.

Long non-coding RNAs in heart failure: an obvious lnc

Heart failure is a life-threatening and costly ailment characterized by structural and functional impairment of the heart. Despite major advances in understanding protein-mediated transcriptional control and signaling pathways that underlie the cellular and interstitial alterations of heart failure, significant therapeutical breakthroughs for innovative treatments of this disease are still missing. The recent extensive profiling of the mammalian transcriptome has revealed a large number of long non-coding RNAs (lncRNAs) that play a diversity of important regulatory roles in gene expression. In here, we focus on a recent work by Ounzain and colleagues comprising genome-wide profiling of the cardiac transcriptome after myocardial infarction with an emphasis on the identification of novel heart-specific lncRNAs.

Long Noncoding RNA: Recent Updates in Atherosclerosis

Long noncoding RNAs belong to a class of noncoding RNAs longer than 200 nucleotides with the epigenetic regulation potential. As a novel molecular regulator, lncRNAs are often dysregulated in various pathological conditions and display multiple functions in a wide range of biological processes. Given that recent studies have indicated that lncRNAs are involved in atherosclerosis-related smooth muscle cell, endothelial cell, macrophage and lipid metabolism regulation, it is pertinent to understand the potential function of lncRNAs in atherosclerosis development. This review will highlight the recent updates of lncRNAs in atherogenesis and also discuss their potential roles as novel therapeutic targets.

Expression signature of lncRNAs and their potential roles in cardiac fibrosis of post-infarct mice

The present study aimed to investigate whether long non-coding RNAs (lncRNAs) are involved in cardiac fibrogenesis induced by myocardial infarction (MI). The differentially expressed lncRNAs and mRNAs in peri-infarct region of mice 4 weeks after MI were selected for bioinformatic analysis including gene ontology (GO) enrichment, pathway and network analysis. Left ventricular tissue levels of lncRNAs and mRNAs were compared between MI and sham control mice, using a false discovery rate (FDR) of <5%. Out of 55000 lncRNAs detected, 263 were significantly up-regulated and 282 down-regulated. Out of 23000 mRNAs detected, 142 were significantly up-regulated and 67 down-regulated. Among the differentially expressed lncRNAs, 53 were up-regulated by ≥2.0-fold change and 37 down-regulated by ≤0.5-fold change. Nine up-regulated and five down-regulated lncRNAs were randomly selected for quantitative real-time PCR (qRT-PCR) verification. GO and pathway analyses revealed 173 correlated lncRNA-mRNA pairs for 57 differentially expressed lncRNAs and 20 differentially expressed genes which are related to the development of cardiac fibrosis. We identified TGF-β3 as the top-ranked gene, a critical component of the transforming growth factor-β (TGF-β) and mitogen activated protein kinase (MAPK) signalling pathways in cardiac fibrosis. NONMMUT022554 was identified as the top-ranked lncRNA, positively correlated with six up-regulated genes, which are involved in the extracellular matrix (ECM)-receptor interactions and the phosphoinositid-3 kinase/protein kinase B (PI3K-Akt) signalling pathway. Our study has identified the expression signature of lncRNAs in cardiac fibrosis induced by MI and unravelled the possible involvement of the deregulated lncRNAs in cardiac fibrosis and the associated pathological processes.

Upregulated lncRNA-UCA1 contributes to progression of hepatocellular carcinoma through inhibition of miR-216b and activation of FGFR1/ERK signaling pathway

The long non-coding RNA (lncRNA) urothelial carcinoma-associated 1 (UCA1) has been recently shown to be dysregulated, which plays an important role in the progression of several cancers. However, the biological role and clinical significance of UCA1 in the carcinogenesis of hepatocellular carcinoma (HCC) remain unclear. Herein, we found that UCA1 was aberrantly upregulated in HCC tissues and associated with TNM stage, metastasis and postoperative survival. UCA1 depletion inhibited the growth and metastasis of HCC cell lines in vitro and in vivo. Furthermore, UCA1 could act as an endogenous sponge by directly binding to miR-216b and downregulation miR-216b expression. In addition, UCA1 could reverse the inhibitory effect of miR-216b on the growth and metastasis of HCC cells, which might be involved in the derepression of fibroblast growth factor receptor 1 (FGFR1) expression, a target gene of miR-216b, and the activation of ERK signaling pathway. Taken together, our data highlights the pivotal role of UCA1 in the tumorigenesis of HCC. Moreover, the present study elucidates a novel lncRNA-miRNA-mRNA regulatory network that is UCA1-miR-216b-FGFR1-ERK signaling pathway in HCC, which may help to lead a better understanding the pathogenesis of HCC and probe the feasibility of lncRNA-directed diagnosis and therapy for this deadly disease.

The long noncoding RNA CASC2 functions as a competing endogenous RNA by sponging miR-18a in colorectal cancer

Recent evidence highlights the crucial regulatory roles of long noncoding RNAs (lncRNA) in tumor biology. In colorectal cancer (CRC), the expression of several lncRNAs is dysregulated and play essential roles in CRC tumorigenesis. However, the potential biological roles and regulatory mechanisms of the novel human lncRNA, CASC2 (cancer susceptibility candidate 2), in tumor biology are poorly understood. In this study, CASC2 expression was significantly decreased in CRC tissues and CRC cell lines, and decreased expression was significantly more frequent in patients with advanced tumor-node-metastasis stage disease (TNM III and IV) (P = 0.028). Further functional experiments indicate that CASC2 could directly upregulate PIAS3 expression by functioning as a competing endogenous RNA (ceRNA) for miR-18a. This interactions leads to the de-repression of genes downstream of STAT3 and consequentially inhibition of CRC cell proliferation and tumor growth in vitro and in vivo by extending the G₀/G₁-S phase transition. Taken together, these observations suggest CASC2 as a ceRNA plays an important role in CRC pathogenesis and may serve as a potential target for cancer diagnosis and treatment.

Overview of MicroRNAs in Cardiac Hypertrophy, Fibrosis, and Apoptosis

MicroRNAs (miRNAs) are non-coding RNAs that play essential roles in modulating the gene expression in almost all biological events. In the past decade, the involvement of miRNAs in various cardiovascular disorders has been explored in numerous in vitro and in vivo studies. In this paper, studies focused upon the discovery of miRNAs, their target genes, and functionality are reviewed. The selected miRNAs discussed herein have regulatory effects on target gene expression as demonstrated by miRNA/3′ end untranslated region (3′UTR) interaction assay and/or gain/loss-of-function approaches. The listed miRNA entities are categorized according to the biological relevance of their target genes in relation to three cardiovascular pathologies, namely cardiac hypertrophy, fibrosis, and apoptosis. Furthermore, comparison across 86 studies identified several candidate miRNAs that might be of particular importance in the ontogenesis of cardiovascular diseases as they modulate the expression of clusters of target genes involved in the progression of multiple adverse cardiovascular events. This review illustrates the involvement of miRNAs in diverse biological signaling pathways and provides an overview of current understanding of, and progress of research into, of the roles of miRNAs in cardiovascular health and disease.

Long noncoding RNA H19 regulates EZH2 expression by interacting with miR-630 and promotes cell invasion in nasopharyngeal carcinoma

The long non-coding RNA (lncRNA) H19 has been recently shown to participate in the progression of cancer, including metastasis. However, the biological role of H19 and the underlying mechanisms mediating its functions in nasopharyngeal carcinoma (NPC) remain unclear. Herein, we found that H19 was overexpressed in NPC tissues and poorly differentiated cell lines. Knockdown of H19 significantly inhibited the invasive ability of NPC cells. Moreover, H19 affected the expression of enhancer of zeste homolog 2 (EZH2), which has also been observed to be up-regulated in NPC and to promote cell invasion. Rather than direct interaction, H19 regulated EZH2 expression by suppressing the activity of miR-630, which is a repressor of EZH2 and interacts with H19 in a sequence-specific manner. Furthermore, H19 inhibited E-cadherin expression and promoted cell invasion of NPC cells via the miR-630/EZH2 pathway. Our data suggest an important role for H19 in NPC metastasis and suggest the feasibility of therapy for NPC involving modulation of the novel regulatory network.

LncRNAs as new biomarkers to differentiate triple negative breast cancer from non-triple negative breast cancer

Triple negative breast cancer (TNBC) is an aggressive type of breast cancer with high heterogeneity. To date, there is no efficient therapy for TNBC patients and the prognosis is poor. It is urgent to find new biomarkers for the diagnosis of TNBC or efficient therapy targets. As an area of focus in the post-genome period, long non-coding RNAs (lncRNAs) have been found to play critical roles in many cancers, including TNBC. However, there is little information on differentially expressed lncRNAs between TNBC and non-TNBC. We detected the expression levels of lncRNAs in TNBC and non-TNBC tissues separately. Then we analyzed the lncRNA expression signature of TNBC relative to non-TNBC, and found dysregulated lncRNAs participated in important biological processes though Gene Ontology and Pathway analysis. Finally, we validated these lncRNA expression levels in breast cancer tissues and cells, and then confirmed that 4 lncRNAs (RP11-434D9.1, LINC00052, BC016831, and IGKV) were correlated with TNBC occurrence through receiver operating characteristic curve analysis. This study offers helpful information to understand the initiation and development mechanisms of TNBC comprehensively and suggests potential biomarkers for diagnosis or therapy targets for clinical treatment.

Crosstalk between Long Noncoding RNAs and MicroRNAs in Health and Disease

Protein-coding genes account for only a small part of the human genome; in fact, the vast majority of transcripts are comprised of non-coding RNAs (ncRNAs) including long ncRNAs (lncRNAs) and small ncRNAs, microRNAs (miRs). Accumulating evidence indicates that ncRNAs could play critical roles in regulating many cellular processes which are often implicated in health and disease. For example, ncRNAs are aberrantly expressed in cancers, heart diseases, and many other diseases. LncRNAs and miRs are therefore novel and promising targets to be developed into biomarkers for diagnosis and prognosis as well as treatment options. The interaction between lncRNAs and miRs as well as its pathophysiological significance have recently been reported. Mechanistically, it is believed that lncRNAs exert “sponge-like” effects on various miRs, which subsequently inhibits miR-mediated functions. This crosstalk between two types of ncRNAs frequently contributes to the pathogenesis of the disease. In this review, we provide a summary of the recent studies highlighting the interaction between these ncRNAs and the effects of this interaction on disease pathogenesis and regulation.

Unraveling the Expression Profiles of Long Noncoding RNAs in Rat Cardiac Hypertrophy and Functions of lncRNA BC088254 in Cardiac Hypertrophy Induced by Transverse Aortic Constriction

Long noncoding RNAs (lncRNAs), although initially considered as genomic transcription noise, have been demonstrated to play pivotal roles in multiple biological processes and are increasingly recognized as contributors to the pathology of cancer, neurodegenerative diseases, diabetes, heart diseases, and inflammation. However, studies on the roles of lncRNAs in angiocardiopathy, particularly in cardiac hypertrophy, are still preliminary. In our study, differentially expressed lncRNAs in rat cardiac hypertrophy induced by transverse aortic constriction (TAC) were identified by microarray analysis and validated using quantitative real-time polymerase chain reaction (RT-PCR). Briefly, we identified 6,969 lncRNAs, among which 80 lncRNAs were significantly upregulated and 172 lncRNAs were significantly downregulated. Quantitative RT-PCR was used to validate the differential expression of 5 lncRNAs in myocardial tissue RNA. Further, pathway analysis indicated that 25 pathways corresponded to upregulated transcripts and 20 pathways corresponded to downregulated transcripts. Third, by coexpression network analysis, we found a correlation between BC088254 and phb2 (prohibitin 2) and verified this expression by RT-PCR and Western blot. This is the first study to reveal differentially expressed lncRNAs in rat cardiac hypertrophy induced by TAC, indicating potential lncRNA mechanisms of action in myocardial hypertrophy. We also found that lncRNA BC088254 may have a certain role in myocardial hypertrophy induced by TAC and functional relevance between lncRNA BCO88254 and phb2, but the relationship between these two factors is unclear.

Characters, functions and clinical perspectives of long non-coding RNAs

It is well established that most of the human genome and those of other mammals and plants are transcribed into RNA without protein-coding capacity, which we define as non-coding RNA. From siRNA to microRNA, whose functions and features have been well characterized, non-coding RNAs have been a popular topic in life science research over the last decade. Long non-coding RNAs (lncRNAs), however, as a novel class of transcripts, are distinguished from these other small RNAs. Recent studies have revealed a diverse population of lncRNAs with different sizes and functions across different species. These populations are expressed dynamically and act as important regulators in a variety of biological processes, especially in gene expression. Nevertheless, the functions and mechanisms of most lncRNAs remain unclear. In this review, we present recent progress in the identification of lncRNAs, their functions and molecular mechanisms, their roles in human diseases, their potential diagnostic and therapeutic applications as well as newer technologies for identifying deregulated lncRNAs in disease tissues.

UCA1 functions as a competing endogenous RNA to suppress epithelial ovarian cancer metastasis

Urothelial cancer associated 1 (UCA1) is an example of functional long noncoding RNAs involved in many biologic processes. However, little is known about the association between UCA1 expression and metastasis in epithelial ovarian cancer (EOC). Findings of this study confirmed that not only UCA1 was aberrantly upregulated in EOC tissues and cells, but also correlated with status of lymph node metastasis and FIGO stage. Furthermore, univariate and multivariate analyses showed that UCA1 was a prognostic factor for overall survival in EOC patients. In vitro, knockdown of UCA1 reduced the invasion and migration ability of EOC cells. The results showed that UCA1 could function as an endogenous sponge by directly binding to miR-485-5p. Depletion of UCA1 was involved in the downregulation of matrix metallopeptidase 14 (MMP14) expression, a target gene of miR-485-5p. In conclusion, our work indicates that UCA1 is a new prognostic biomarker for EOC, establishing a novel connection among UCA1, miR-485-5p, and MMP14 in EOC metastasis.

Multifaceted role of prohibitin in cell survival and apoptosis

Human eukaryotic prohibitin (prohibitin-1 and prohibitin-2) is a membrane protein with different cellular localizations. It is involved in multiple cellular functions, including energy metabolism, proliferation, apoptosis, and senescence. The subcellular localization of prohibitin may determine its functions. Membrane prohibitin regulate the cellular signaling of membrane transport, nuclear prohibitin control transcription activation and the cell cycle, and mitochondrial prohibitin complex stabilize the mitochondrial genome and modulate mitochondrial dynamics, mitochondrial morphology, mitochondrial biogenesis, and the mitochondrial intrinsic apoptotic pathway. Moreover, prohibitin can translocates into the nucleus or the mitochondria under apoptotic signals and the subcellular shuttling of prohibitin is necessary for apoptosis process. Apoptosis is the process of programmed cell death that is important for the maintenance of normal physiological functions. Consequently, any alteration in the content, post-transcriptional modification (i.e. phosphorylation) or the nuclear or mitochondrial translocation of prohibitin may influence cell fate. Understanding the mechanisms of the expression and regulation of prohibitin may be useful for future research. This review provides an overview of the multifaceted and essential roles played by prohibitin in the regulation of cell survival and apoptosis.

Exploiting the hypoxia sensitive non-coding genome for organ-specific physiologic reprogramming

In this review we highlight the role of non-coding RNAs in the development and progression of cardiac pathology and explore the possibility of disease-associated RNAs serving as targets for cardiac-directed therapeutics. Contextually, we focus on the role of stress-induced hypoxia as a driver of disease development and progression through activation of hypoxia inducible factor 1α (HIF1α) and explore mechanisms underlying HIFα function as an enforcer of cardiac pathology through direct transcriptional coupling with the non-coding transcriptome. In the interest of clarity, we will confine our analysis to cardiac pathology and focus on three defining features of the diseased state, namely metabolic, growth and functional reprogramming. It is the aim of this review to explore possible mechanisms through which HIF1α regulation of the non-coding transcriptome connects to spatiotemporal control of gene expression to drive establishment of the diseased state, and to propose strategies for the exploitation of these unique RNAs as targets for clinical therapy. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.

Non-coding RNAs as modulators of the cardiac fibroblast phenotype

Cardiac fibroblasts represent one of the most frequent cell type in the heart of rodents and humans and alterations of their phenotype have a great impact on cardiac function. Due to aging, ischemic injuries, valvular dysfunctions, hypertension and aortic stenosis, multiple signals trigger the accumulation of extracellular matrix in the cardiac interstitium and perivascular space, leading to structural and functional detrimental changes in the heart. Cardiac fibroblasts are the principal orchestrators of matrix formation and degradation and indirectly regulate cardiac hypertrophy and inflammation. Understanding the molecular bases of their action could provide tools for the treatment of cardiac remodeling. This review summarizes recent evidences on non-coding RNAs, including microRNAs and long non-coding RNAs that modulate the phenotype of cardiac fibroblasts and may serve in the future as targets for novel therapeutic strategies against cardiac fibrosis.

Long Noncoding RNAs in Atherosclerosis

Long noncoding RNAs (lncRNAs) were a group of non-protein-coding RNAs ＞200 nucleotides and participated in biological processes and pathophysiological conditions in vivo or in vitro. Recently, more and more lncRNAs interfering with the progress of atherosclerosis were identified and characterized in the atherogenic cells such as vascular smooth muscle cells (VSMCs), endothelial cells (ECs), and monocytes/macrophages showing that lncRNAs play an important role in the occurrence of atherosclerosis. In this review, we summarized and highlighted the lncRNAs that play a role in the process of atherosclerosis. This study may provide helpful insights regarding further study of lncRNAs associated with atherosclerosis.

miR-23a binds to p53 and enhances its association with miR-128 promoter

Apoptosis plays an important role in cardiac pathology, but the molecular mechanism by which apoptosis regulated remains largely elusive. Here, we report that miR-23a promotes the apoptotic effect of p53 in cardiomyocytes. Our results showed that miR-23a promotes apoptosis induced by oxidative stress. In exploring the molecular mechanism by which miR-23a promotes apoptosis, we found that it sensitized the effect of p53 on miR-128 regulation. It promoted the association of p53 to the promoter region of miR-128, and enhanced the transcriptional activation of p53 on miR-128 expression. miR-128 can downregulate prohibitin expression, and subsequently promote apoptosis. Our data provides novel evidence revealing that miR-23a can stimulate transcriptional activity of p53.

Long noncoding RNA MIR31HG exhibits oncogenic property in pancreatic ductal adenocarcinoma and is negatively regulated by miR-193b

Long noncoding RNAs (lncRNAs) play important regulatory roles in a variety of diseases, including many tumors. However, the functional roles of these transcripts and mechanisms responsible for their deregulation in pancreatic ductal adenocarcinoma (PDAC) are not thoroughly understood. In this study, we discovered that lncRNA MIR31HG is markedly upregulated in PDAC. Knockdown of MIR31HG significantly suppressed PDAC cell growth, induced apoptosis and G1/S arrest, and inhibited invasion, whereas enhanced expression of MIR31HG had the opposite effects. Online database analysis tools showed that miR-193b could target MIR31HG and we found an inverse correlation between MIR31HG and miR-193b in PDAC specimens. Inhibition of miR-193b expression significantly upregulated the MIR31HG level, while overexpression of miR-193b suppressed MIR31HG's expression and function, suggesting that MIR31HG is negatively regulated by miR-193b. Moreover, using luciferase reporter and RIP assays, we provide evidence that miR-193b directly targeted MIR31HG by binding to two microRNA binding sites in the MIR31HG sequence. On the other hand, MIR31HG may act as an endogenous 'sponge' by competing for miR-193b binding to regulate the miRNA targets. Collectively, these results demonstrate that MIR31HG functions as an oncogenic lncRNA that promotes tumor progression, and miR-193b targets not only protein-coding genes but also the lncRNA, MIR31HG.

Function and Therapeutic Potential of Noncoding RNAs in Cardiac Fibrosis

Cardiac fibrosis as a result of excessive extracellular matrix deposition leads to stiffening of the heart, which can eventually lead to heart failure. An important event in cardiac fibrosis is the transformation of fibroblasts into myofibroblasts, which secrete large amounts of extracellular matrix proteins. Although the function of protein-coding genes in myofibroblast activation and fibrosis have been a topic of investigation for a long time, it has become clear that noncoding RNAs also play key roles in cardiac fibrosis. This review discusses the involvement of microRNAs and long noncoding RNAs in cardiac fibrosis and summarizes the issues related to translating these findings into real-life therapies.

Evidence of Mitochondrial Dysfunction within the Complex Genetic Etiology of Schizophrenia

Genetic evidence has supported the hypothesis that schizophrenia (SZ) is a polygenic disorder caused by the disruption in function of several or many genes. The most common and reproducible cellular phenotype associated with SZ is a reduction in dendritic spines within the neocortex, suggesting alterations in dendritic architecture may cause aberrant cortical circuitry and SZ symptoms. Here, we review evidence supporting a multifactorial model of mitochondrial dysfunction in SZ etiology and discuss how these multiple paths to mitochondrial dysfunction may contribute to dendritic spine loss and/or underdevelopment in some SZ subjects. The pathophysiological role of mitochondrial dysfunction in SZ is based upon genomic analyses of both the mitochondrial genome and nuclear genes involved in mitochondrial function. Previous studies and preliminary data suggest SZ is associated with specific alleles and haplogroups of the mitochondrial genome, and also correlates with a reduction in mitochondrial copy number and an increase in synonymous and nonsynonymous substitutions of mitochondrial DNA. Mitochondrial dysfunction has also been widely implicated in SZ by genome-wide association, exome sequencing, altered gene expression, proteomics, microscopy analyses, and induced pluripotent stem cell studies. Together, these data support the hypothesis that SZ is a polygenic disorder with an enrichment of mitochondrial targets.

Long Non-Coding RNAs as Master Regulators in Cardiovascular Diseases

Cardiovascular disease is the leading cause of death in the United States, accounting for nearly one in every seven deaths. Over the last decade, various targeted therapeutics have been introduced, but there has been no corresponding improvement in patient survival. Since the mortality rate of cardiovascular disease has not been significantly decreased, efforts have been made to understand the link between heart disease and novel therapeutic targets such as non-coding RNAs. Among multiple non-coding RNAs, long non-coding RNA (lncRNA) has emerged as a novel therapeutic in cardiovascular medicine. LncRNAs are endogenous RNAs that contain over 200 nucleotides and regulate gene expression. Recent studies suggest critical roles of lncRNAs in modulating the initiation and progression of cardiovascular diseases. For example, aberrant lncRNA expression has been associated with the pathogenesis of ischemic heart failure. In this article, we present a synopsis of recent discoveries that link the roles and molecular interactions of lncRNAs to cardiovascular diseases. Moreover, we describe the prevalence of circulating lncRNAs and assess their potential utilities as biomarkers for diagnosis and prognosis of heart disease.

Discovery and functional characterization of cardiovascular long noncoding RNAs

Recent advances in sequencing and genomic technologies have resulted in the discovery of thousands of previously unannotated long noncoding RNAs (lncRNAs). However, their function in the cardiovascular system remains elusive. Here we review and discuss considerations for cardiovascular lncRNA discovery, annotation and functional characterization. Although we primarily focus on the heart, the proposed pipeline should foster functional and mechanistic exploration of these transcripts in various cardiovascular pathologies. Moreover, these insights could ultimately lead to novel therapeutic approaches targeting lncRNAs for the amelioration of cardiovascular diseases including heart failure.

Down-regulation of miR-133a and miR-539 are associated with unfavorable prognosis in patients suffering from osteosarcoma

Background

MicroRNAs (miRNAs) play key roles in cancer development and progression. The purpose of the present study was to determine the expression levels of miR-133a and miR-539 in osteosarcoma patients and to further investigate the clinicopathological, and prognostic value of these miRNAs.

Methods

The expression levels of miR-133a and miR-539 were determined by qRT-PCR. Associations between miRNAs expressions and various clinicopathological characteristics were analyzed. Survival rate was determined with Kaplan–Meier and statistically analyzed with the log-rank method between groups. Survival data were evaluated through multivariate Cox regression analysis

Results

Our findings revealed that the miR-133a expression was significantly decreased in clinical osteosarcoma tissues compared to adjacent normal bone tissues. The expression level of miR-539 was decreased in clinical osteosarcoma tissues as compared to those adjacent normal tissues. Low expressions of miR-133a and miR-539 were significantly association with advanced TNM stage (P = 0.002; P = 0.001), and metastasis or recurrence (P = 0.001; P = 0.01). Furthermore, Kaplan–Meier survival analysis and log-rank test showed that the low expressions of miR-133a and miR-539 were correlated with the reduced overall survival of osteosarcoma patients. Multivariate Cox proportional hazards model showed that decreased expressions of miR-133a and miR-539 (P = 0.007; P = 0.02), TNM stage (P = 0.001; P = 0.002), and metastasis or recurrence (P = 0.005; P = 0.026) were independent prognostic markers of overall survival of patients.

Conclusion

These results suggest that decreased miR-133a and miR-539 expressions may participate in the progression of osteosarcoma. Together, these results showed that miR-133a and miR-539 may have their role in both progression and prognosis of osteosarcoma.

Lncing epigenetic control of transcription to cardiovascular development and disease

Transcriptional and epigenetic regulation is critical for proper heart development, cardiac homeostasis, and pathogenesis. Long noncoding RNAs have emerged as key components of the transcriptional regulatory pathways that govern cardiac development as well as stress response, signaling, and remodeling in cardiac pathologies. Within the past few years, studies have identified many long noncoding RNAs in the context of cardiovascular biology and have begun to reveal the key functions of these transcripts. In this review, we discuss the growing roles of long noncoding RNAs in different aspects of cardiovascular development as well as pathological responses during injury or disease. In addition, we discuss diverse mechanisms by which long noncoding RNAs orchestrate cardiac transcriptional programs. Finally, we explore the exciting potential of this novel class of transcripts as biomarkers and novel therapeutic targets for cardiovascular diseases.

Microvascular invasion in hepatocellular carcinoma overexpression promotes cell proliferation and inhibits cell apoptosis of hepatocellular carcinoma via inhibiting miR-199a expression

OBJECTIVES

Long non-coding RNA (lncRNA) associated with microvascular invasion in hepatocellular carcinoma (MVIH) has been recently reported to act as a predictor for the poor recurrence-free survival of hepatocellular carcinoma (HCC) after hepatectomy. However, the biological role of MVIH in the tumorigenesis of HCC is still unclear.

METHODS

In the study reported here, MVIH expression levels were detected by real-time polymerase chain reaction (PCR) in tumor tissue of HCC patients and in HCC cells, including SMMC7721 and HepG2 cells. Cell viability and apoptosis were determined by MTT and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) methods, respectively. The model of transplantation tumor of HepG2 cells in nude mice was used to evaluate the effects of MVIH and miR-199a on HCC in vivo.

RESULTS

MVIH expression was significantly increased and miR-199a expression was significantly decreased in tumor tissue and HCC cells. si-MVIH inhibited HCC cell viability and promoted cell apoptosis, but this effect was reversed by miR-199a inhibitor. Luciferase reporter assay and RNA immunoprecipitation experiment showed that miR-199a had a direct binding ability to MVIH RNA. In nude mice with transplantation, the tumor volume was reduced by si-MVIH, and miR-199a inhibitor canceled this decrease.

CONCLUSION

MVIH promoted cell growth and inhibited cell apoptosis of HCC via inhibiting miR-199a expression.

Long noncoding RNA FER1L4 suppresses cancer cell growth by acting as a competing endogenous RNA and regulating PTEN expression

Aberrantly expressed long noncoding RNAs (lncRNAs) are associated with various cancers. However, the roles of lncRNAs in the pathogenesis of most cancers are unclear. Here, we report that the lncRNA FER1L4 (fer-1-like family member 4, pseudogene) acts as a competing endogenous RNA (ceRNA) to regulate the expression of PTEN (a well-known tumor suppressor gene) by taking up miR-106a-5p in gastric cancer. We observed that FER1L4 was downregulated in gastric cancer and that its level corresponded with that of PTEN mRNA. Both FER1L4 and PTEN mRNA were targets of miR-106a-5p. Further experiments demonstrated that FER1L4 downregulation liberates miR-106a-5p and decreases the abundances of PTEN mRNA and protein. More importantly, FER1L4 downregulation accelerated cell proliferation by promoting the G₀/G₁ to S phase transition. We conclude that one mechanism by which lncRNAs function in in tumorigenesis is as ceRNAs for tumor suppressor mRNAs.