lncRNA作为竞争性内源RNA在非小细胞肺癌中的作用

长链非编码RNA(long non-coding RNA,lncRNA)参与肿瘤的多种生理、病理进程.研究表明,lncRNA可通过与微小RNA (microRNA, mi RNA)反应元件相互作用,并与其他RNA分子形成竞争性内源RNA (competing endogenous RNA,ceRNA)的调控网络,参与基因的表达调控.lncRNA以ceRNA方式参与非小细胞肺癌(non-small cell lung cancer,NSCLC)的发生发展过程,为揭示NSCLC的分子机理开拓了新的思路,也为NSCLC的治疗提供新的靶点.本文在课题组前期发现NSCLC相关ceRNA基础上,主要讨论lncRNA作为ceRNA在NSCLC中高表达、低表达及治疗相关方面的作用.     

Sl‐lncRNA15492 interacts with Sl‐miR482a and affects Solanum lycopersicum immunity against Phytophthora infestans

Long non‐coding RNAs (lncRNAs) are involved in the resistance of plants to infection by pathogens via interactions with microRNAs (miRNAs). Long non‐coding RNAs are cleaved by miRNAs to produce phased small interfering RNAs (phasiRNAs), which, as competing endogenous RNAs (ceRNAs), function as decoys for mature miRNAs, thus inhibiting their expression, and contain pre‐miRNA sequences to produce mature miRNAs. However, whether lncRNAs and miRNAs mediate other molecular mechanisms during plant resistance to pathogens is unknown. In this study, as a positive regulator, Sl‐lncRNA15492 from tomato (Solanum lycopersicum Zaofen No. 2) plants affected tomato resistance to Phytophthora infestans. Gain‐ and loss‐of‐function experiments and RNA ligase‐mediated 5′‐amplification of cDNA ends (RLM‐5′ RACE) also revealed that Sl‐miR482a was negatively involved in tomato resistance by targeting Sl‐NBS‐LRR genes and that silencing of Sl‐NBS‐LRR1 decreased tomato resistance. Sl‐lncRNA15492 inhibited the expression of mature Sl‐miR482a, whose precursor was located within the antisense sequence of Sl‐lncRNA15492. Further degradome analysis and additional RLM‐5′ RACE experiments verified that mature Sl‐miR482a could also cleave Sl‐lncRNA15492. These results provide a mechanism by which lncRNAs might inhibit precursor miRNA expression through antisense strands of lncRNAs, and demonstrate that Sl‐lncRNA15492 and Sl‐miR482a mutually inhibit the maintenance of Sl‐NBS‐LRR1 homeostasis during tomato resistance to P. infestans.     

lncRNA H19 contributes to oxidative damage repair in the early age‐related cataract by regulating miR‐29a/TDG axis

Age‐related cataract (ARC) is caused by the exposure of the lens to UVB which promotes oxidative damage and cell death. This study aimed to explore the role of lncRNA H19 in oxidative damage repair in early ARC. lncRNAs sequencing technique was used to identify different lncRNAs in the lens of early ARC patients. Human lens epithelial cells (HLECs) were exposed to ultraviolet irradiation; and 8‐OHdG ELISA, Cell counting kit 8 (CCK8), EDU, flow cytometry and TUNEL assays were used to detect DNA damage, cell viability, proliferation and apoptosis. Luciferase assay was used to examine the interaction among H19, miR‐29a and thymine DNA glycosylase (TDG) 3'UTR. We found that lncRNA H19 and TDG were highly expressed while miR‐29a was down‐regulated in the three types of early ARC and HLECs exposed to ultraviolet irradiation, compared to respective controls. lncRNA H19 knockdown aggravated oxidative damage, reduced cell viability and proliferation, and promoted apoptosis in HLECs, while lncRNA H19 overexpression led to opposite effects in HLECs. Mechanistically, miR‐29a bound TDG 3'UTR to repress TDG expression. lncRNA H19 up‐regulated the expression of TDG by repressing miR‐29a because it acted as ceRNA through sponging miR‐29a. In conclusion, the interaction among lncRNA H19, miR‐29a and TDG is involved in early ARC. lncRNA H19 could be a useful marker of early ARC and oxidative damage repair pathway of lncRNA H19/miR‐29a/TDG may be a promising target for the treatment of ARC.     

Identification and development of long non‐coding RNA‐associated regulatory network in colorectal cancer

Colorectal cancer (CRC) is one of the leading causes of cancer‐associated death globally. Long non‐coding RNAs (lncRNAs) have been identified as micro RNA (miRNA) sponges in a competing endogenous RNA (ceRNA) network and are involved in the regulation of mRNA expression. This study aims to construct a lncRNA‐associated ceRNA network and investigate the prognostic biomarkers in CRC. A total of 38 differentially expressed (DE) lncRNAs, 23 DEmiRNAs and 27 DEmRNAs were identified by analysing the expression profiles of CRC obtained from The Cancer Genome Atlas (TCGA). These RNAs were chosen to develop a ceRNA regulatory network of CRC, which comprised 125 edges. Survival analysis showed that four lncRNAs, six miRNAs and five mRNAs were significantly associated with overall survival. A potential regulatory axis of ADAMTS9‐AS2/miR‐32/PHLPP2 was identified from the network. Experimental validation was performed using clinical samples by quantitative real‐time PCR (qRT‐PCR), which showed that expression of the genes in the axis was associated with clinicopathological features and the correlation among them perfectly conformed to the ‘ceRNA theory’. Overexpression of ADAMTS9‐AS2 in colon cancer cell lines significantly inhibited the miR‐32 expression and promoted PHLPP2 expression, while ADAMTS9‐AS2 knockdown had the opposite effects. The constructed novel ceRNA network may provide a comprehensive understanding of the mechanisms of CRC carcinogenesis. The ADAMTS9‐AS2/miR‐32/PHLPP2 regulatory axis may serve as a potential therapeutic target for CRC.     

Down‐regulated lncRNA SLC25A5‐AS1 facilitates cell growth and inhibits apoptosis via miR‐19a‐3p/PTEN/PI3K/AKT signalling pathway in gastric cancer

Mounting evidence has illustrated the vital roles of long non‐coding RNAs (lncRNAs in gastric cancer (GC). Nevertheless, the majority of their roles and mechanisms in GC are still largely unknown. In this study, we investigate the roles of lncRNA SLC25A5‐AS1 on tumourigenesis and explore its potential mechanisms in GC. The results showed that the expressions of SLC25A5‐AS1 in GC were significantly lower than that of adjacent normal tissues, which were significantly associated with tumour size, TNM stage and lymph node metastasis. Moreover, SLC25A5‐AS1 could inhibit GC cell proliferation, induce G1/G1 cell cycle arrest and cell apoptosis in vitro, as well as GC growth in vivo. Dual‐luciferase reporter assay confirmed the direct interaction between SLC25A5‐AS1 and miR‐19a‐3p, rescue experiment showed that co‐transfection miR‐19a‐3p mimics and pcDNA‐SLC25A5‐AS1 could partially restore the ability of GC cell proliferation and the inhibition of cell apoptosis. The mechanism analyses further found that SLC25A5‐AS1 might act as a competing endogenous RNAs (ceRNA), which was involved in the derepression of PTEN expression, a target gene of miR‐19a‐3p, and regulate malignant phenotype via PI3K/AKT signalling pathway in GC. Taken together, this study indicated that SLC25A5‐AS1 was down‐regulated in GC and functioned as a suppressor in the progression of GC. Moreover, it could act as a ceRNA to regulate cellular behaviours via miR‐19a‐3p/PTEN/PI3K/AKT signalling pathway. Thus, SLC25A5‐AS1 might be served as a potential target for cancer therapeutics in GC.     

Long non‐coding RNA cardiac hypertrophy‐associated regulator governs cardiac hypertrophy via regulating miR‐20b and the downstream PTEN/AKT pathway

Pathological cardiac hypertrophy (CH) is a key factor leading to heart failure and ultimately sudden death. Long non‐coding RNAs (lncRNAs) are emerging as a new player in gene regulation relevant to a wide spectrum of human disease including cardiac disorders. Here, we characterize the role of a specific lncRNA named cardiac hypertrophy‐associated regulator (CHAR) in CH and delineate the underlying signalling pathway. CHAR was found markedly down‐regulated in both in vivo mouse model of cardiac hypertrophy induced by pressure overload and in vitro cellular model of cardiomyocyte hypertrophy induced by angiotensin II (AngII) insult. CHAR down‐regulation alone was sufficient to induce hypertrophic phenotypes in healthy mice and neonatal rat ventricular cells (NRVCs). Overexpression of CHAR reduced the hypertrophic responses. CHAR was found to act as a competitive endogenous RNA (ceRNA) to down‐regulate miR‐20b that we established as a pro‐hypertrophic miRNA. We experimentally established phosphatase and tensin homolog (PTEN), an anti‐hypertrophic signalling molecule, as a target gene for miR‐20b. We found that miR‐20b induced CH by directly repressing PTEN expression and indirectly increasing AKT activity. Moreover, CHAR overexpression mitigated the repression of PTEN and activation of AKT by miR‐20b, and as such, it abrogated the deleterious effects of miR‐20b on CH. Collectively, this study characterized a new lncRNA CHAR and unravelled a new pro‐hypertrophic signalling pathway: lncRNA‐CHAR/miR‐20b/PTEN/AKT. The findings therefore should improve our understanding of the cellular functionality and pathophysiological role of lncRNAs in the heart.     

Knockdown of lncRNA AK139328 alleviates myocardial ischaemia/reperfusion injury in diabetic mice via modulating miR‐204‐3p and inhibiting autophagy

This study was aimed at investigating the effects of lncRNA AK139328 on myocardial ischaemia/reperfusion injury (MIRI) in diabetic mice. Ischaemia/reperfusion (I/R) model was constructed in normal mice (NM) and diabetic mice (DM). Microarray analysis was utilized to identify lncRNA AK139328 overexpressed in DM after myocardial ischaemia/reperfusion (MI/R). RT‐qPCR assay was utilized to investigate the expressions of lncRNA AK139328 and miR‐204‐3p in cardiomyocyte and tissues. Left ventricular end diastolic diameter (LVEDD), left ventricular end systolic diameter (LVESD), left ventricular ejection fraction (LVEF) and fractioning shortening (FS) were obtained by transthoracic echocardiography. Haematoxylin‐eosin (HE) staining and Masson staining were utilized to detect the damage of myocardial tissues degradation of myocardial fibres and integrity of myocardial collagen fibres. Evans Blue/TTC staining was used to determine the myocardial infarct size. TUNEL staining was utilized to investigate cardiomyocyte apoptosis. The targeted relationship between lncRNA AK139328 and miR‐204‐3p was confirmed by dual‐luciferase reporter gene assay. MTT assay was used for analysis of cardiomyocyte proliferation. Western blot was utilized to investigate the expression of alpha smooth muscle actin (α‐SMA), Atg7, Atg5, LC3‐II/LC3‐I and p62 marking autophagy. Knockdown of lncRNA AK139328 relieved myocardial ischaemia/reperfusion injury in DM and inhibited cardiomyocyte autophagy as well as apoptosis of DM. LncRNA AK139328 modulated miR‐204‐3p directly. MiR‐204‐3p and knockdown of lncRNA AK139328 relieved hypoxia/reoxygenation injury via inhibiting cardiomyocyte autophagy. Silencing lncRNA AK139328 significantly increased miR‐204‐3p expression and inhibited cardiomyocyte autophagy, thereby attenuating MIRI in DM.     

Reconstruction and analysis of the aberrant lncRNA‐miRNA‐mRNA network based on competitive endogenous RNA in CESC

A growing body of studies has demonstrated that long non‐coding RNA (lncRNA) are regarded as the primary section of the ceRNA network. This is thought to be the case owing to its regulation of protein‐coding gene expression by functioning as miRNA sponges. However, functional roles and regulatory mechanisms of lncRNA‐mediated ceRNA in cervical squamous cell carcinoma (CESC), as well as their use for potential prediction of CESC prognosis, remains unknown. The aberrant expression profiles of mRNA, lncRNA, and miRNA of 306 cervical squamous cancer tissues and three adjacent cervical tissues were obtained from the TCGA database. A lncRNA‐mRNA‐miRNA ceRNA network in CESC was constructed. Meanwhile, Gene Ontology (GO) and KEGG pathway analysis were performed using Cytoscape plug‐in BinGo and DAVID database. We identified a total of 493 lncRNA, 70 miRNA, and 1921 mRNA as differentially expressed profiles. An aberrant lncRNA‐mRNA‐miRNA ceRNA network was constructed in CESC, it was composed of 50 DElncRNA, 18 DEmiRNA, and 81 DEmRNA. According to the overall survival analysis, 3 out of 50 lncRNA, 10 out of 81 mRNA, and 1 out of 18 miRNA functioned as prognostic biomarkers for patients with CESC (P value < 0.05). We extracted the sub‐network in the ceRNA network and found that two novel lncRNA were recognized as key genes. These included lncRNA MEG3 and lncRNA ADAMTS9‐AS2. The present study provides a new insight into a better understanding of the lncRNA‐related ceRNA network in CESC, and the novel recognized ceRNA network will help us to improve our understanding of lncRNA‐mediated ceRNA regulatory mechanisms in the pathogenesis of CESC.     

LncRNA‐DANCR contributes to lung adenocarcinoma progression by sponging miR‐496 to modulate mTOR expression

Long non‐coding RNAs (lncRNAs) have emerged as new and important regulators of pathological processes including tumour development. In this study, we demonstrated that differentiation antagonizing non‐protein coding RNA (DANCR) was up‐regulated in lung adenocarcinoma (ADC) and that the knockdown of DANCR inhibited tumour cell proliferation, migration and invasion and restored cell apoptosis rescued; cotransfection with a miR‐496 inhibitor reversed these effects. Luciferase reporter assays showed that miR‐496 directly modulated DANCR; additionally, we used RNA‐binding protein immunoprecipitation (RIP) and RNA pull‐down assays to further confirm that the suppression of DANCR by miR‐496 was RISC‐dependent. Our study also indicated that mTOR was a target of miR‐496 and that DANCR could modulate the expression levels of mTOR by working as a competing endogenous RNA (ceRNA). Furthermore, the knockdown of DANCR reduced tumour volumes in vivo compared with those of the control group. In conclusion, this study showed that DANCR might be an oncogenic lncRNA that regulates mTOR expression through directly binding to miR‐496. DANCR may be regarded as a biomarker or therapeutic target for ADC.     

LncRNA‐PAGBC acts as a microRNA sponge and promotes gallbladder tumorigenesis

Long noncoding RNAs (lncRNAs) play roles in the development and progression of many cancers; however, the contributions of lncRNAs to human gallbladder cancer (GBC) remain largely unknown. In this study, we identify a group of differentially expressed lncRNAs in human GBC tissues, including prognosis‐associated gallbladder cancer lncRNA (lncRNA‐PAGBC), which we find to be an independent prognostic marker in GBC. Functional analysis indicates that lncRNA‐PAGBC promotes tumour growth and metastasis of GBC cells. More importantly, as a competitive endogenous RNA (ceRNA), lncRNA‐PAGBC competitively binds to the tumour suppressive microRNAs miR‐133b and miR‐511. This competitive role of lncRNA‐PAGBC is required for its ability to promote tumour growth and metastasis and to activate the AKT/mTOR pathway. Moreover, lncRNA‐PAGBC interacts with polyadenylate binding protein cytoplasmic 1 (PABPC1) and is stabilized by this interaction. This work provides novel insight on the molecular pathogenesis of GBC.     

Integrative analysis of competing endogenous RNA networks reveals the functional lncRNAs in heart failure

Heart failure has become one of the top causes of death worldwide. It is increasing evidence that lncRNAs play important roles in the pathology processes of multiple cardiovascular diseases. Additionally, lncRNAs can function as ceRNAs by sponging miRNAs to affect the expression level of mRNAs, implicating in numerous biological processes. However, the functional roles and regulatory mechanisms of lncRNAs in heart failure are still unclear. In our study, we constructed a heart failure‐related lncRNA‐mRNA network by integrating probe re‐annotation pipeline and miRNA‐target interactions. Firstly, some lncRNAs that had the central topological features were found in the heart failure‐related lncRNA‐mRNA network. Then, the lncRNA‐associated functional modules were identified from the network, using bidirectional hierarchical clustering. Some lncRNAs that involved in modules were demonstrated to be enriched in many heart failure‐related pathways. To investigate the role of lncRNA‐associated ceRNA crosstalks in certain disease or physiological status, we further identified the lncRNA‐associated dysregulated ceRNA interactions. And we also performed a random walk algorithm to identify more heart failure‐related lncRNAs. All these lncRNAs were verified to show a strong diagnosis power for heart failure. These results will help us to understand the mechanism of lncRNAs in heart failure and provide novel lncRNAs as candidate diagnostic biomarkers or potential therapeutic targets.     

基于TCGA和GEO数据库的胃癌lncRNA筛选与ceRNA网络构建

胃癌（gastric cancer,GC）是我国最常见的恶性肿瘤之一,严重危害人类健康。胃癌发病机制复杂,缺乏特异性预后生物标志物。长链非编码RNA（long non?coding RNA,lncRNA）可作为竞争性内源RNA（competing endogenous RNA,ceRNA）,影响microRNA（miRNA）与mRNA的结合,从而影响胃癌的发生、发展。基于TCGA和GEO数据库的转录组数据,筛选GC中差异表达的lncRNAs,并构建基于6条lncRNAs（HAGLROS、TMEM92?AS1、LINC01745、HOXC?AS3、SEMA3B?AS1、FEZF1?AS1）的lncRNA?miRNA?mRNA网络。网络核心基因的KEGG/GO富集和蛋白质互作分析结果显示,lncRNA可能通过miRNA海绵吸附作用,调控胃癌的发生、发展与转移。AC011352.1、AC087636.1、AC093627.1、GAS1RR与胃癌患者的预后相关性具有统计学意义（P<0.05）,并可能成为胃癌患者潜在的预后生物标志物。     

肿瘤发生过程中miRNA与lncRNA的相互作用

非编码RNA(non-coding RNA,ncRNA)是生物体内普遍存在,且对生命活动具有重要调控作用的生物分子.以微RNA（microRNA,miRNA）和长链非编码RNA（long non coding RNA,lncRNA）为代表的ncRNA分子在肿瘤发生和发展过程中都有重要的作用.越来越多研究发现,miRNA和lncRNA之间的关系是非常密切的,某些lncRNA(如H19和BIC)可以作为miRNA的前体,通过加工成miRNA而发挥作用.有些miRNA通过作用于lncRNA影响肿瘤的发生(如：miR-129与MEG3,let-7与H19);同样地,有些lncRNA通过作用于miRNA影响肿瘤的发生(如：HULC与miR-372,PTCSC3与miR-574-5p,ciRS-7与miR-7,Sry与miR-138).miRNA与lncRNA之间既可以直接相互作用,也可以通过其它分子（特别是蛋白质或蛋白质复合物）间接地影响着肿瘤的发生和发展.揭示miRNA和lncRNA相互作用在肿瘤发生中的作用可以为肿瘤的诊断和治疗提供新思路.