Impact of chronic intermittent hypoxia on the long non-coding RNA and mRNA expression profiles in myocardial infarction

Chronic intermittent hypoxia (CIH) is the primary feature of obstructive sleep apnoea (OSA), a crucial risk factor for cardiovascular diseases. Long non-coding RNAs (lncRNAs) in myocardial infarction (MI) pathogenesis have drawn considerable attention. However, whether CIH participates in the modulation of lncRNA profiles during MI is yet unclear. To investigate the influence of CIH on MI, cardiac damage was assessed by histology and echocardiography, and lncRNA and mRNA integrated microarrays were screened. MI mouse model showed myocardial hypertrophy, aggravated inflammation and fibrosis, and compromised left ventricle function under CIH. Compared with normoxia, 644 lncRNAs and 1084 differentially expressed mRNAs were identified following CIH for 4 weeks, whereas 1482 lncRNAs and 990 mRNAs were altered at 8 weeks. Strikingly, reoxygenation after CIH markedly affected 1759 lncRNAs and 778 mRNAs. Of these, 11 lncRNAs modulated by CIH were restored after reoxygenation and were validated by qPCR. The GO terms and KEGG pathways of genes varied significantly by CIH. lncRNA-mRNA correlation further showed that lncRNAs, NONMMUT032513 and NONMMUT074571 were positively correlated with ZEB1 and negatively correlated with Cmbl. The current results demonstrated a causal correlation between CIH and lncRNA alternations during MI, suggesting that lncRNAs might be responsible for MI aggravation under CIH.     

Different expression profile of mRNA and long noncoding RNA in autoimmune thyroid diseases patients

Increasing evidence has found that long noncoding RNAs (lncRNAs) and message RNAs (mRNAs) play an important role in the progress of autoimmune thyroid diseases (AITD). So, in this study, the different expressed of lncRNA and mRNA was screened by microarray analysis and quantitative real-time polymerase chain reaction (PCR). To further investigate the relationship among the differentially expressed genes, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and Gene ontology (GO) were used for biofunctions and signaling pathways analysis, respectively. Finally, the interaction relationship between lncRNA and mRNAs was analysis with lncRNA-mRNA coexpression network. The result found that the abnormal expression of lncRNAs and mRNAs were 1615 and 1913, respectively. The altered genes included CD40LG, IFNG, CTLA4, FAS, STAT1, STAT3, and STAT4. These were enriched in presentation and antigen processing, Th1 and Th2 cell differentiation, natural killer cell-mediated cytotoxicity, B cell receptor signaling pathway, Th17 cell differentiation, and cell adhesion molecules (CAMs), all of which had been suggested to be associated with immunopathogenic mechanisms and AITD-induced pathophysiologic changes. A coexpression network profile was contained with 126 network nodes and 477 connections which were based on seven mRNAs and 119 interacted lncRNAs. The outcomes of differentially expressed lncRNAs and their coreralated mRNAs in our study revealed that lncRNAs involved in immunopathogenic mechanisms may play a crital role in the pathogenesis of AITD.     

Identification of lncRNA‐associated differential subnetworks in oesophageal squamous cell carcinoma by differential co‐expression analysis

Differential expression analysis has led to the identification of important biomarkers in oesophageal squamous cell carcinoma (ESCC). Despite enormous contributions, it has not harnessed the full potential of gene expression data, such as interactions among genes. Differential co‐expression analysis has emerged as an effective tool that complements differential expression analysis to provide better insight of dysregulated mechanisms and indicate key driver genes. Here, we analysed the differential co‐expression of lncRNAs and protein‐coding genes (PCGs) between normal oesophageal tissue and ESCC tissues, and constructed a lncRNA‐PCG differential co‐expression network (DCN). DCN was characterized as a scale‐free, small‐world network with modular organization. Focusing on lncRNAs, a total of 107 differential lncRNA‐PCG subnetworks were identified from the DCN by integrating both differential expression and differential co‐expression. These differential subnetworks provide a valuable source for revealing lncRNA functions and the associated dysfunctional regulatory networks in ESCC. Their consistent discrimination suggests that they may have important roles in ESCC and could serve as robust subnetwork biomarkers. In addition, two tumour suppressor genes (AL121899.1 and ELMO2), identified in the core modules, were validated by functional experiments. The proposed method can be easily used to investigate differential subnetworks of other molecules in other cancers.     

Identification of mitochondrial function‐associated lncRNAs in septic mice myocardium

The present study aimed to analyze long noncoding RNA (lncRNA) and messenger RNA (mRNA) expression profiles in septic mice heart and to identify potential lncRNAs and mRNAs that be responsible for cardiac mitochondrial dysfunction during sepsis. Mice were treated with 10 mg/kg of lipopolysaccharides to induce sepsis. LncRNAs and mRNAs expression were evaluated by using lncRNA and mRNA microarray or real‐time polymerase chain reaction technique. LncRNA‐mRNA coexpression network assay, Gene Ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed. The results showed that 1275 lncRNAs were differentially expressed in septic myocardium compared with those in the control group. A total of 2769 mRNAs were dysregulated in septic mice heart, most of which are mainly related to the process of inflammation, mitochondrial metabolism, oxidative stress, and apoptosis. Coexpression network analysis showed that 14 lncRNAs were highly correlated with 11 mitochondria‐related differentially expressed mRNA. Among all lncRNAs and their cis‐acting mRNAs, 41 lncRNAs‐mRNA pairs (such as NONMMUG004378 and Apaf1 gene) were enriched in GO terms and KEGG pathways. In summary, we gained some specific lncRNAs and their potential target mRNAs that might be involved in mitochondrial dysfunction in septic myocardium. These findings provide a panoramic view of lncRNA and might allow developing new treatment strategies for sepsis.     

低氧mtDNA3010A/G基因型变异诱导的lncRNA-mRNA共表达网络变化

目的: 分析mtDNA3010A/G变异在急性缺氧条件下的长链非编码RNA(lncRNA)和信使RNA(mRNA)的共表达网络变化,探讨关键lncRNA和mRNA在低氧诱导的基因表达调控中的作用。方法: 筛选线粒体DNA(mtDNA)3010-5178-10400的基因型组合A-C-C和G-C-C,以骨肉瘤细胞经溴化乙锭处理后形成的无线粒体细胞(ρ⁰206细胞)为供体,构建mtDNA3010A和mtDNA3010G基因型融合细胞。经1%O₂处理24 h后,采用lncRNA-mRNA共表达芯片检测两种融合细胞的差异表达lncRNA和mRNA,荧光定量聚合酶链式法验证差异显著的mRNA,运用生物信息学方法构建lncRNA-mRNA共表达网络,预测差异lncRNA的靶基因,并对差异显著的mRNA和预测靶基因进行基因本体(GO)和京都基因与基因组大百科全书(KEGG)预测分析。结果: 经1%O₂处理24 h后,与mtDNA3010G融合细胞相比,mtDNA3010A融合细胞表达上调的lncRNA有688个,超过2倍的有21个,表达下调的lncRNA有1098个,超过2倍的有4个;表达上调的mRNA有1151个,超过2倍的有14个,表达下调的mRNA有539个,超过2倍的有3个。结论: mtDNA3010A/G基因型变异在缺氧条件下能够影响lncRNA-mRNA调控网络的变化,差异表达的lncRNA和mRNA可能在低氧诱导的基因表达调控网络中发挥重要作用,有望成为从线粒体角度调控低氧反应的靶点。     

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.     

Identification of messenger and long noncoding RNAs associated with gallbladder cancer via gene expression profile analysis

The present study aimed to investigate the long noncoding RNAs (lncRNAs) and messenger RNAs (mRNAs) involved in the progression of gallbladder cancer and explore the potential physiopathologic mechanisms of gallbladder cancer in terms of competing endogenous RNAs (ceRNAs). The original lncRNA and mRNA expression profile data (nine gallbladder cancer tissues samples and nine normal gallbladder samples) in GSE76633 was downloaded from the Gene Expression Omnibus database. Differentially expressed mRNAs and lncRNAs between gallbladder cancer tissue and normal control were selected and the pathways in which they are involved were analyzed using bioinformatics analyses. MicroRNAs (miRNAs) were also predicted based on the differentially expressed mRNAs. Finally, the co-expression relation between lncRNA and mRNA was analyzed and the ceRNA network was constructed by combining the lncRNA-miRNA, miRNA-mRNA, and lncRNA-mRNA pairs. Overall, 373 significantly differentially expressed mRNAs and 47 lncRNAs were identified between cancer and normal tissue samples. The upregulated genes were significantly enriched in the extracellular matrix (ECM)-receptor interaction pathway, while the downregulated genes were involved in the complement and coagulation cascades. Altogether, 128 co-expression relations between lncRNA and mRNA were obtained. In addition, 196 miRNA-mRNA regulatory relations and 145 miRNA-lncRNA relation pairs were predicted. Finally, the lncRNA-miRNA-gene ceRNA network was constructed by combining the three types of relation pairs, such as XLOC_011309-miR-548c-3p-SPOCK1 and XLOC_012588-miR-765-CEACAM6. mRNAs and lncRNAs may be involved in gallbladder cancer progression via ECM-receptor interaction pathways and the complement and coagulation cascades. Moreover, ceRNAs such as XLOC_011309-miR-548c-3p-SPOCK1 and XLOC_012588-miR-765-CEACAM6 can also be implicated in the pathogenesis of gallbladder cancer.     

The role of lncRNA HCG18 in human diseases

A substantial number of long noncoding RNAs (lncRNAs) have been identified as potent regulators of human disease. Human leukocyte antigen complex group 18 (HCG18) is a new type of lncRNA that has recently been proven to play an important role in the occurrence and development of various diseases. Studies have found that abnormal expression of HCG18 is closely related to the clinicopathological characteristics of many diseases. More importantly, HCG18 was also found to promote disease progression by affecting a series of cell biological processes. This article mainly discusses the expression characteristics, clinical characteristics, biological effects and related regulatory mechanisms of HCG18 in different human diseases, providing a scientific theoretical basis for its early clinical application.     

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.     

Screening and bioinformatics analysis of mRNA,long non-coding RNA and circular RNA expression profiles in mucoepidermoid carcinoma of salivary gland

Mucoepidermoid carcinoma (MEC) of salivary gland is a disease characterized by high rate of diatant metastasis, and associated with poor outcomes. However, the molecular mechanisms underlying the MEC remain poorly understand. Here, we simultaneously detected, for the first time, the expression profiles of mRNAs, lncRNAs, and circRNAs in four pairs of MEC and matched non-carcinoma tissues by microarrays. A total of 3612?mRNA, 3091 lncRNAs, and 284 circRNAs were altered during the pathogenesis of MEC. The functions of these differentially expressed RNAs were predicted by Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Co-expression networks of lncRNA-mRNA and circRNA-miRNA were conducted to uncovered the hidden ceRNA mechanisms. Moreover, NONHSAT154433.1 that associated with ADAM12 and hsa_circ_0012342 were further screened and confirmed using qRT-PCR analysis. In conclusion, this study provides a systematic perspective on the potential function of non-coding RNAs (ncRNAs) in the molecular mechanisms of MEC. Among these, NONHSAT154433.1 and hsa_circ_0012342 might be served as potential prognostic biomarkers and therapeutic target of MEC.     

Long non-coding RNAs: new players in ocular neovascularization

Pathological neovascularization are the most prevalent causes of moderate or severe vision loss. Long non-coding RNAs (lncRNAs) have emerged as a novel class of regulatory molecules involved in numerous biological processes and complicated diseases. However, the role of lncRNAs in ocular neovascularization is still unclear. Here, we constructed a murine model of ocular neovascularization, and determined lncRNA expression profiles using microarray analysis. We identified 326 or 51 lncRNAs that were significantly either up-regulated or down-regulated in the vaso-obliteration or neovascularization phase, respectively. Based on Pearson correlation analysis, lncRNAs/mRNAs co-expression networks were constructed. GO enrichment analysis of lncRNAs-co-expressed mRNAs indicated that the biological modules were correlated with chromosome organization, extracellular region and guanylate cyclase activator activity in the vaso-obliteration phase, and correlated with cell proliferation, extracellular region and guanylate cyclase regulator activity in the neovascularization phase. KEGG pathway analysis indicated that MAPK signaling was the most significantly enriched pathway in both phases. Importantly, Vax2os1 and Vax2os2 were not only dynamically expressed in the vaso-obliteration and neovascularization phases, but also significantly altered in the aqueous humor of patients with neovascular age-related macular degeneration (AMD), suggesting a potential role of lncRNAs in the regulation of ocular neovascularization. Taken together, this study provided novel insights into the molecular pathogenesis of ocular neovascularization. The intervention of dysregulated lncRNA could become a potential target for the prevention and treatment of ocular vascular diseases.     

Retracted: Long noncoding RNA HCG22 suppresses proliferation and metastasis of bladder cancer cells by regulation of PTBP1

Multifarious biological functions of long noncoding RNAs (lncRNAs) have been reported in various cancers including bladder cancer (BCa). This study aims to determine the biological role of a certain lncRNA in BCa. Consistent with the data of The Cancer Genome Atlas database, it was validated that lncRNA HLA complex group 22 (HCG22) was weakly expressed in BCa samples and lowly expressed HCG22 was closely correlated with low overall survival of the BCa patient. To verify the role of HCG22 in BCa progression, functional experiments were carried out in two representative BCa cells (J82 and T24) and the negative effects of HCG22 expression on the cell proliferation, migration, and epithelial–mesenchymal transition were identified. Mechanistically, polypyrimidine tract-binding protein 1 (PTBP1), which was highly expressed in BCa tissues and cell lines, was negatively regulated by HCG22 and the PTBP1-mediated Warburg effect was also obstructed by HCG22. Furthermore, HCG22 modulated the expression of PTBP1 through destabilizing human antigen R (HuR). And functional rescue assays confirmed that HCG22 functioned in bladder cancer through downregulating PTBP1. In conclusion, the present study revealed that HCG22 inhibited BCa progression via the HuR/PTBP1 axis, opening new prospects for potent therapeutic regimens for BCa patients.