LncRNA TP73-AS1 enhances the malignant properties of pancreatic ductal adenocarcinoma by increasing MMP14 expression through miRNA -200a sponging

Pancreatic ductal adenocarcinoma (PDAC) is an invasive and aggressive cancer that remains a major threat to human health across the globe. Despite advances in cancer treatments and diagnosis, the prognosis of PDAC patients remains poor. New and more effective PDAC therapies are therefore urgently required. In this study, we identified a novel host factor, namely the LncRNA TP73-AS1, as overexpressed in PDAC tissues compared to adjacent healthy tissue samples. The overexpression of TP-73-AS1 was found to correlate with both PDAC stage and lymph node metastasis. To reveal its role in PDCA, we targeted TP73-AS1 using LnRNA inhibitors in a range of pancreatic cancer (PC) cell lines. We found that the inhibition of TP73-AS1 led to a loss of MMP14 expression in PC cells and significantly inhibited their migratory and invasive capacity. No effects of TP73-AS1 on cell survival or proliferation were observed. Mechanistically, we found that TP73-AS1 suppressed the expression of the known oncogenic miR-200a. Taken together, these data highlight the prognostic potential of TP73-AS1 for PC patients and highlight it as a potential anti-PDAC therapeutic target.     

LINC01128 regulates the development of osteosarcoma by sponging miR‐299‐3p to mediate MMP2 expression and activating Wnt/β‐catenin signalling pathway

Osteosarcoma (OS) is one of the most common metastatic bone cancers, which results in significant morbidity and mortality. The important role of long non‐coding RNAs (lncRNAs) in the biological processes of OS has been demonstrated through several studies. In the current study, we evaluated the role of the lncRNA, LINC01128, in OS. We analysed the expression of LINC01128 in three OS gene expression omnibus (GEO) data sets {"type":"entrez-geo","attrs":{"text":"GSE21257","term_id":"21257"}}GSE21257, {"type":"entrez-geo","attrs":{"text":"GSE36001","term_id":"36001"}}GSE36001 and {"type":"entrez-geo","attrs":{"text":"GSE42352","term_id":"42352"}}GSE42352. The expression of LINC01128 in OS tissues and matched non‐tumour tissues obtained from 50 OS patients was detected using qRT‐PCR. The association between LINC01128 expression and overall survival of OS patients was evaluated using the Kaplan‐Meier method. The effects of LINC01128 knockdown and overexpression were evaluated through in vitro and in vivo assays. The LINC01128/miR‐299‐3p/ MMP2 axis was verified using dual‐luciferase reporter assay and qRT‐PCR assays. GEO data sets analysis revealed that the expression of LINC01128 was increased in OS. Elevated LINC01128 expression was accompanied by shorter overall survival in OS patients. Functional studies revealed that LINC01128 knockdown reduced the proliferation, migration and invasion of OS cells both in vitro and in vivo. Mechanistically, LINC01128 sponged miR‐299‐3p to increase MMP2 expression. Rescue assays determined the role of the LINC01128/miR‐299‐3p/MMP2 axis in the proliferation, migration and invasion of OS cells. Additionally, the Wnt/β‐catenin signalling pathway was activated by LINC01128 and MMP2 in OS cell lines. In summary, this study demonstrates that LINC01128 facilitates OS by functioning as a sponge of miR‐299‐3p, thus promoting MMP2 expression and activating the Wnt/β‐catenin signalling pathway.     

LNRLMI: Linear neighbour representation for predicting lncRNA‐miRNA interactions

LncRNA and miRNA are key molecules in mechanism of competing endogenous RNAs(ceRNA), and their interactions have been discovered with important roles in gene regulation. As supplementary to the identification of lncRNA‐miRNA interactions from CLIP‐seq experiments, in silico prediction can select the most potential candidates for experimental validation. Although developing computational tool for predicting lncRNA‐miRNA interaction is of great importance for deciphering the ceRNA mechanism, little effort has been made towards this direction. In this paper, we propose an approach based on linear neighbour representation to predict lncRNA‐miRNA interactions (LNRLMI). Specifically, we first constructed a bipartite network by combining the known interaction network and similarities based on expression profiles of lncRNAs and miRNAs. Based on such a data integration, linear neighbour representation method was introduced to construct a prediction model. To evaluate the prediction performance of the proposed model, k‐fold cross validations were implemented. As a result, LNRLMI yielded the average AUCs of 0.8475 ± 0.0032, 0.8960 ± 0.0015 and 0.9069 ± 0.0014 on 2‐fold, 5‐fold and 10‐fold cross validation, respectively. A series of comparison experiments with other methods were also conducted, and the results showed that our method was feasible and effective to predict lncRNA‐miRNA interactions via a combination of different types of useful side information. It is anticipated that LNRLMI could be a useful tool for predicting non‐coding RNA regulation network that lncRNA and miRNA are involved in.     

Integrated analysis of ceRNA network and tumor-infiltrating immune cells in esophageal cancer

Background: Esophageal cancer (ESCA) is one of the most commonly diagnosed cancers in the world. Tumor immune microenvironment is closely related to tumor prognosis. The present study aimed at analyzing the competing endogenous RNA (ceRNA) network and tumor-infiltrating immune cells in ESCA.Methods: The expression profiles of mRNAs, lncRNAs, and miRNAs were downloaded from the Cancer Genome Atlas database. A ceRNA network was established based on the differentially expressed RNAs by Cytoscape. CIBERSORT was applied to estimate the proportion of immune cells in ESCA. Prognosis-associated genes and immune cells were applied to establish prognostic models basing on Lasso and multivariate Cox analyses. The survival curves were constructed with Kaplan–Meier method. The predictive efficacy of the prognostic models was evaluated by the receiver operating characteristic (ROC) curves.Results: The differentially expressed mRNAs, lncRNAs, and miRNAs were identified. We constructed the ceRNA network including 23 lncRNAs, 19 miRNAs, and 147 mRNAs. Five key molecules (HMGB3, HOXC8, HSPA1B, KLHL15, and RUNX3) were identified from the ceRNA network and five significant immune cells (plasma cells, T cells follicular helper, monocytes, dendritic cells activated, and neutrophils) were selected via CIBERSORT. The ROC curves based on key genes and significant immune cells all showed good sensitivity (AUC of 3-year survival: 0.739, AUC of 5-year survival: 0.899, AUC of 3-year survival: 0.824, AUC of 5-year survival: 0.876). There was certain correlation between five immune cells and five key molecules.Conclusion: The present study provides an effective bioinformatics basis for exploring the potential biomarkers of ESCA and predicting its prognosis.     

LncRNA TUG1 acts as a competing endogenous RNA to mediate CTGF expression by sponging miR-133b in myocardial fibrosis after myocardial infarction

Myocardial fibrosis (MF) is one of the basic causes of many cardiovascular diseases. Noncoding RNAs (ncRNAs), including microRNA (miRNA) and long noncoding RNA (lncRNA), have been reported to play an indispensable role in MF. The current work is focused on investigating the biological role of lncRNA taurine upregulation gene 1 (TUG1) in activating cardiac myofibroblasts as well as the underlying mechanism. The outcome revealed that after myocardial infarction TUG1 expression increased and miR-133b expression decreased in the rat model of MF. The expression level of TUG1 increased following AngII treatment in cardiac myofibroblast. TUG1 knockdown inhibited the Ang-II induced cardiac myofibroblast activation and TUG1 overexpression increased proliferation and collagen generation of cardiac myofibroblasts. Bioinformatic prediction programs predicted that TUG1 had MRE directly combined with miR-133b seed sequence, luciferase activity, and RIP experiments indicated that TUG1, acted as a sponger and interacted with miR-133b in cardiac myofibroblasts. Furthermore, a target of miR-133b was CTGF and CTGF knockdown counteracted the promotion of MF by miR-133b knockdown. Collectively, our study suggested that TUG1 mediates CTGF expression by sponging miR-133b in the activation of cardiac myofibroblasts. The current work reveals a unique role of the TUG1/miR-133b/CTGF axis in MF, thus suggesting its immense therapeutic potential in the treatment of cardiac diseases.