Long non-coding RNAs: Novel links in respiratory diseases (Review)

Effect of runx2b deficiency in intermuscular bones on the regulatory network of lncRNA-miRNA-mRNA

Intermuscular bones (IBs) are mineralized spicules that negatively impact the quality and value of fish products. Runx2b is a crucial modulator in promoting bone formation through regulating osteoblast differentiation. Previous studies suggested that loss of runx2b gene completely inhibited IBs formation in zebrafish. However, how the whole transcriptome, including mRNA and non-coding RNA (ncRNA), affects the IBs development in runx2b-/- zebrafish are not known. The aim of this study was to identify the regulatory networks of differentially expressed (DE) lncRNAs, miRNAs, and mRNAs in zebrafish with and without IBs (runx2b+/+ fish and runx2b-/- fish) utilizing high-throughput sequencing techniques. All together there are 1051 mRNAs, 456 lncRNAs, and 18 miRNAs differentially expressed were found between these two strains. The analysis of Kyoto Encyclopedia of Genes and Genomes (KEGG) has highlighted significant pathways linked to the development of IBs, specifically the TGF-beta and Wnt signaling pathways, and a number of genes concentrated on these two signaling pathways related to the formation of IBs. Further, 1989 competing endogenous RNA (ceRNA) networks were created according to the correlation among mRNAs, miRNAs and lncRNAs. The ceRNA networks results revealed 52 ceRNA pairs related to the IBs formation, consisting of 52 mRNAs, 37 lncRNAs, and 6 miRNAs. Of these, we found that dre-miR-2189 was the key element of ceRNA pairs, interacting with 19 mRNAs and 11 lncRNAs, and MSTRG.13175.1 could regulate sp7 expression by interacting with dre-miR-2189 to function in osteogenic differentiation. Subsequent experiments at the cellular level also revealed the interaction mechanism. The outcomes indicated a crucial role of miRNAs and lncRNAs in the development of fish IBs, which offer new views into the functions of ncRNAs involved in IBs formation.

m5C modification of LINC00324 promotes angiogenesis in glioma through CBX3/VEGFR2 pathway

Angiogenesis plays a major role in tumor initiation, progression, and metastasis. This is why finding antiangiogenic targets is essential in the treatment of gliomas. In this study, NSUN2 and LINC00324 were significantly upregulated in conditionally cultured glioblastoma endothelial cells (GECs). Knockdown of NSUN2 or LINC00324 inhibits GECs angiogenesis. NSUN2 increased the stability of LINC00324 by m5C modification and upregulated LINC00324 expression. LINC00324 competes with the 3'UTR of CBX3 mRNA to bind to AUH protein, reducing the degradation of CBX3 mRNA. In addition, CBX3 directly binds to the promoter region of VEGFR2, enhances VEGFR2 transcription, and promotes GECs angiogenesis. These findings demonstrated NSUN2/LINC00324/CBX3 axis plays a crucial role in regulating glioma angiogenesis, which provides new strategies for glioma therapy.

Identification and characterization of lncRNAs and the interaction of lncRNA-mRNA in Epinephelus coioides induced with Singapore grouper iridovirus infection

Singapore grouper iridovirus (SGIV) is a highly pathogenic double-stranded DNA virus, and the fatality rate of SGIV-infected grouper is more than 90%. Up to now, there is no effective methods to control the disease. Long non-coding RNAs (lncRNAs) might play an important role in individual growth and development, immune regulation and other life processes. In this study, lncRNAs were identified in Epinephelus coioides, an important economic aquaculture marine fish in China and Southeast Asia, and the regulatory relationships of lncRNAs and mRNA response to SGIV infection were analyzed. A total of 11,678 lncRNAs were identified and classified from the spleen and GS (grouper spleen) cells. 105 differentially expressed lncRNAs (DElncRNAs) were detected during SGIV infection. The lncRNAs and the regulated mRNAs were analyzed using co-expression network, lncRNA target gene annotation and GO enrichment. At 24 and 48 h after SGIV infection, 118 and 339 lncRNA-mRNA pairs in GS cells were detected, and 728 and 688 differentially expressed lncRNA-mRNA pairs in spleen were obtained, respectively. GO and KEGG were used to predict the DE lncRNAs' target genes, and deduce the DE lncRNAs-affected signaling pathways. In GS cells, lncRNAs might participate in cell part, binding and catalytic activity; and lncRNAs might be involved in immune system process and transcription factor activity in spleen. These data demonstrated that lncRNAs could regulate the expression of immune-related genes response to viral infection, and providing a new insight into understanding the complexity of immune regulatory networks mediated by lncRNAs during viral infection in teleost fish.

Message in hand: the application of CRISPRi, RNAi, and LncRNA in adenocarcinoma

Gene editing interference technology has been flourishing for more than 30 years. It has always been a common means to interfere with the expression of particular genes. Today it has shown a broad application prospect in clinical treatment, especially in adenocarcinoma treatment. In just a few years, the CRISPRi technology has attracted much z attention with its precise targeting and convenient operability significantly promoted the transformation from bench to bedside, and won the Nobel Prize in Chemistry 2020. In recent years, the importance of non-coding RNA has led LncRNA research to the center. At the same time, it also recalls the surprises obtained in laboratory and clinic research by RNAi technologies such as microRNA, siRNA, and shRNA at the beginning of the century. Therefore, this article focuses on CRISPRi, RNAi, and LncRNA to review their gene interference mechanisms currently expected to be translational research. Their applications and differences in adenocarcinoma research will also be described powerfully. It will provide a helpful reference for scientists to understand better and apply several RNA interference technologies.

Coexpression Network Analysis of lncRNA Associated with Overexpression of DNMT1 in Esophageal Epithelial Cells

Screening and preliminary identification of high DNMT1 expression-related lncRNA, which is involved in various interrelated signaling pathways, has led to the development of a theoretical basis for various types of disease mechanisms. Differential expression profiles of lncRNA and mRNA were identified in a microarray. Ten lncRNAs with high levels of variation were identified by qRT-PCR. KEGG and GO analyses were used to identify differentially expressed mRNAs. Six signaling pathways were selected based on the KEGG results of the lncRNA-mRNA expression network analysis. From the microarrays in the experimental and control groups, we found a total of 6987 differentially expressed lncRNAs, and 7421 differentially expressed mRNAs were obtained (P < 0.05; fold change > 2.0x). GO analysis and KEGG pathway analysis showed high expression of DNMT1 in esophageal epithelial cells. Nine pathways were involved in mRNA upregulation, including natural killer cell-mediated cytotoxicity and many other prominent biochemical pathways. Forty-six pathways were associated with downregulated mRNAs and ribosomes involving multiple biological pathways. Coexpression network analysis showed that 8 mRNAs and 16 lncRNAs were linked to the p53 signaling pathway. In Helicobacter pylori infections, interactions occurred between 22 lncRNAs and 11 mRNAs in the ErbB signaling pathway and between 19 lncRNAs and 8 mRNAs in epithelial cell signal transduction. Interactions were present between 19 lncRNAs and 5 mRNAs in the sphingolipid signaling pathway, along with interactions between 21 lncRNAs and 12 mRNAs in the PI3K-Akt signaling pathway. Cytotoxicity interactions occurred between 22 lncRNAs and 9 mRNAs in natural killer cells.

Role of Long Non-Coding RNAs in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a debilitating condition of the pulmonary circulatory system that occurs in patients of all ages and if untreated, eventually leads to right heart failure and death. Despite existing medical treatment options that improve survival and quality of life, the disease remains incurable. Thus, there is an urgent need to develop novel therapies to treat this disease. Emerging evidence suggests that long non-coding RNAs (lncRNAs) play critical roles in pulmonary vascular remodeling and PAH. LncRNAs are implicated in pulmonary arterial endothelial dysfunction by modulating endothelial cell proliferation, angiogenesis, endothelial mesenchymal transition, and metabolism. LncRNAs are also involved in inducing different pulmonary arterial vascular smooth muscle cell phenotypes, such as cell proliferation, apoptosis, migration, regulation of the phenotypic switching, and cell cycle. LncRNAs are essential regulators of gene expression that affect various diseases at the chromatin, transcriptional, post-translational, and even post-translational levels. Here, we focus on the role of LncRNAs and their molecular mechanisms in the pathogenesis of PAH. We also discuss the current research challenge and potential biomarker and therapeutic potentials of lncRNAs in PAH.

Versatile Target-Guided Screen for Discovering Bidirectional Transcription Inhibitors of a Trinucleotide Repeat Disease

Myotonic dystrophy type 1 originates from d(CTG·CAG) repeats that undergo aberrant expansion during normal processing because the d(CTG) repeat forms stable hairpin structures. Bidirectional transcription of d(CTG·CAG) yields two RNA transcripts that undergo repeat-associated non-ATG (RAN) translation to form homopolymeric proteins. Thus, both the r(CUG) transcript and the r(CAG) transcript are known to be toxic. We report a pairwise fragment-based, target-guided approach to screen for proximity-induced click dimers formed on the nucleic acid template. This screen uses an azide/alkyne clickable fragment library of nucleic acid-binding ligands incubated in parallel, pairwise reactions as an alternative to our previously reported one-pot screening method. MALDI-TOF mass spectroscopy was used to detect template assisted click products. Hit compounds inhibited the in vitro transcription of d(CTG·CAG)₉₀ bidirectionally with IC₅₀ values in the low micromolar range. This approach may be broadly applicable to other trinucleotide repeat diseases and in targeting other disease-associated nucleic acid sequences.

Long noncoding RNA MST1P2 promotes cervical cancer progression by sponging with microRNA miR-133b

Long noncoding RNA (lnc RNA) is aberrant expressed in many kinds of tumors and may be concerned with the occurrence and progression of tumors. Lnc RNA MST1P2 is increased in cervical cancer (CC), but its mechanism in CC has not been clarified. In this study, RT-qPCR was employed to analyze Lnc MST1P2 and miR-133b expression. CCK8 and cell apoptosis assay detect the proliferation optical density (OD) value and apoptosis rate. Cell metastasis was evaluated by Wound-healing assay and Transwell assay. Dual-Luciferase assay analyzed the relationship between Lnc MST1P2 and miR-133b. In vivo experiment was performed by establishing xenograft animal model. We found that Lnc MST1P2 is obviously overexpression in CC tissues and cells. Si-Lnc MST1P2 obviously repressed cell growth, cell migration, and cell invasion in Hela and SIHA cells. Moreover, Si-Lnc MST1P2 suppressed CC tumorigenesis in vivo. Dual-Luciferase assay and RT-qPCR assay further proved that Lnc MST1P2 has a negative regulation to miR-133b. miR-133b up-regulation inhibited cell viability and metastasis of Hela and SIHA cells. miR-133b inhibition notably decreased the anti-cancer effect of si-Lnc MST1P2. LncRNA MST1P2 serves as a Cervical Cancer oncogene by sponging with miR-133b.

Long Noncoding RNAs in Myocardial Ischemia-Reperfusion Injury

Following an acute myocardial infarction, reperfusion therapy is currently the most effective way to save the ischemic myocardium; however, restoring blood flow may lead to a myocardial ischemia-reperfusion injury (MIRI). Recent studies have confirmed that long-chain noncoding RNAs (LncRNAs) play important roles in the pathophysiology of MIRIs. These LncRNA-mediated roles include cardiomyocyte apoptosis, autophagy, necrosis, oxidative stress, inflammation, mitochondrial dysfunction, and calcium overload, which are regulated through the expression of target genes. Thus, LncRNAs may be used as clinical diagnostic markers and therapeutic targets to treat or prevent MIRI. This review evaluates the research on LncRNAs involved in MIRIs and provides new ideas for preventing and treating this type of injury.

Genome-Wide Integrated Analysis Revealed Functions of lncRNA-miRNA-mRNA Interaction in Growth of Intermuscular Bones in Megalobrama amblycephala

Intermuscular bone (IB) occurs in the myosepta of teleosts. Its existence has an adverse influence on the edible and economic value of fish, especially for aquaculture species belonging to Cypriniformes. The growth mechanism of IBs is quite lacking. In this study, we firstly used single molecular real-time sequencing (SMRT) technology to improve the draft genome annotation and full characterization of the transcriptome for one typical aquaculture species, blunt snout bream (Megalobrama amblycephala). The long non-coding RNA (lncRNA), microRNA (miRNA), and messenger RNA (mRNA) expression profiles in two IB growth stages (1 and 3 years old) were compared through transcriptome and degradome analyses. A total of 126 miRNAs, 403 mRNAs, and 353 lncRNAs were found to be differentially expressed between the two stages. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that the significantly upregulated map2k6 and cytc in the MAPK/p53 signaling pathway and the significantly downregulated lama3 and thbs4b in the extracellular matrix (ECM)–receptor pathway may play a key regulatory role in IB growth. Bioinformatics analysis subsequently revealed 14 competing endogenous RNA (ceRNA) pairs related to the growth of IBs, consisting of 10 lncRNAs, 7 miRNAs, and 10 mRNAs. Of these, dre-miR-24b-3p and dre-miR-193b-3p are core regulatory factors interacting with four lncRNAs and three mRNAs, the interaction mechanism of which was also revealed by subsequent experiments at the cellular level. In conclusion, our data showed that IBs had higher activity of cell apoptosis and lower mineralization activity in IB_III compared to IB_I via interaction of MAPK/p53 and ECM–receptor signaling pathways. The downregulated zip1 interacted with miR-24a-3p and lnc017705, decreased osteoblast differentiation and Ca²⁺ deposition in the IB_III stage. Our identified functional mRNAs, lncRNAs, and miRNAs provide a data basis for in-depth elucidation of the growth mechanism of teleost IB.

Comprehensive in silico identification of impacts of ACE2 SNPs on COVID-19 susceptibility in different populations

The COVID-19 pandemic emerges a reminder that wide spectrum discrepancy in response to SARS-CoV-2 infection and antiviral drugs among different populations might be due to their different ACE2 SNPs and/or miRNAs profile. ACE2 is the major component for SARS-CoV-2s' cell entry, and disruption of its 3D structure could influence virus-ACE2 interaction. In this study we aimed to investigate the consequence of 16,860 SNPs within ACE2 on its expression as well as protein folding, function, and stability by using several beneficial bioinformatics tools. Only 64 SNPs including 60 intronic, and 4 missense showed different frequencies among different populations. Two missense SNPs including rs149039346 and rs147311723 have been predicted to strongly influence the function and stability of ACE2. rs1514283 creates new acceptor splice site. Also, rs4646175 creates new donor and acceptor splice site. PolymiRTS, and miRSNPs have predicted that rs3746444, rs113808830, and rs3751304 showed a MAF > 0.001, and disrupted mRNA target sites or mRNA function. Finally, rs3746444 hsa-miR-499a-3p, rs113808830 hsa-miR-4532, rs3751304 hsa-miR-6763-3p and hsa-miR-26b-5p were strongly hybridized with ACE2 and might influence its function. Collectively, this study shed some light on fundamental roles of ACE2 SNPs for its interaction with COVID-19, and consequently susceptibility to virus. Therefore, different responses of patients with COVID-19 to ACE2 blocker drugs might be due to their unique ACE2 SNPs. We further discussed the impact of SNPs on miRNAs profile as a factor that may modulate drug response or susceptibility to COVID-19.

LncRNAs and circular RNAs as endothelial cell messengers in hypertension: mechanism insights and therapeutic potential

Endothelial cells are major constituents in the vasculature, and they act as important players in vascular homeostasis via secretion/release of vasodilators and vasoconstrictors. In healthy arteries, endothelial cells play a key role in the regulation of vascular tone, cellular adhesion, and angiogenesis. A shift in the functions of the blood vessels toward vasoconstriction, proinflammatory state, oxidative stress and deficiency of nitric oxide (NO) might lead to endothelial dysfunction, a key event implicated in the pathophysiology of cardiovascular metabolic diseases, including diabetes, atherosclerosis, arterial hypertension and pulmonary arterial hypertension (PAH). Thus, reversibility of endothelial dysfunction may be beneficial for maintaining vascular homeostasis. In recent years, accumulative evidence has documented that noncoding RNAs (ncRNAs) are critically involved in endothelial homeostasis. Specifically, long noncoding RNAs (lncRNAs) and circular RNAs are highly expressed in endothelial cells where they serve as important mediators in normal endothelial functions. Dysregulation of lncRNAs and circular RNAs has been tightly associated with hypertension-related endothelial dysfunction. In this review, we will summarize the current progression and underlying mechanisms of lncRNA and circular RNA in endothelial cell biology under hypertensive conditions. We will also highlight their potential as biomarkers or therapeutic targets for hypertension and its associated endothelial dysfunction.

Long non-coding RNA MALAT1 exacerbates acute respiratory distress syndrome by upregulating ICAM-1 expression via microRNA-150-5p downregulation

Acute respiratory distress syndrome (ARDS) is a severe form of acute lung injury in which severe inflammatory responses induce cell apoptosis, necrosis, and fibrosis. This study investigated the role of lung adenocarcinoma transcript 1 (MALAT1) in ARDS and the underlying mechanism involved. The expression of MALAT1, microRNA-150-5p (miR-150-5p), and intercellular adhesion molecule-1 (ICAM-1) was determined in ARDS patients and lipopolysaccharide (LPS)-treated human pulmonary microvascular endothelial cells (HPMECs). Next, the interactions among MALAT1, miR-150-5p, and ICAM-1 were explored. Gain- or loss-of-function experiments in HPMECs were employed to determine cell apoptosis and inflammation. Furthermore, a mouse xenograft model of ARDS was established in order to verify the function of MALAT1 in vivo. MALAT1 and ICAM-1 were upregulated, while miR-150-5p was downregulated in both ARDS patients and LPS-treated HPMECs. MALAT1 upregulated ICAM-1 expression by competitively binding to miR-150-5p. MALAT1 silencing or miR-150-5p overexpression was shown to suppress HPMEC apoptosis, decrease the expressions of pro-inflammatory cytokines (IL-6, IL-1β and TNF-α) and E-selectin in HPMECs, as well as alleviated lung injury in nude mice. These findings demonstrated that MALAT1 silencing can potentially suppress HPMEC apoptosis and alleviate lung injury in ARDS via miR-150-5p-targeted ICAM-1, suggestive of a novel therapeutic target for ARDS.

Long non-coding RNA LINC00152 acts as a sponge of miRNA-193b-3p to promote tongue squamous cell carcinoma progression

Dysregulated expression of long non-coding RNAs has been determined to be important in cancer development; however, their role in tongue squamous cell carcinoma (TSCC) progression and carcinogenesis, to the best of our knowledge, is yet to be elucidated. The present study revealed that long intergenic non-coding RNA 00152 (LINC00152) expression was significantly increased in human TSCC tissues compared with in tissues from matched controls using RT-qPCR. In TSCC cell lines, CAL-27 and SCC-9, LINC00152 was revealed to promote TSCC cell proliferation, enhance cell cycle progression and inhibit cell apoptosis. Additionally, migration and invasion of TSCC cell lines was increased in response to LINC00152 overexpression. Mechanistically, LINC00152 was determined to be localized in the cytoplasm and acted as a microRNA (miR)-193b-3p sponge, and LINC00152 knockdown or miR-193b-3p mimics both inhibited PI3K signaling pathway activation and downstream AKT phosphorylation; therefore, promoting TSCC progression in vitro. Overall, the results of the present study suggested that increased LINC00152 expression in TSCC tissues may act as a sponge of miR-193b-3p to promote cancer progression in vitro.

Linking lncRNAs to regulation, pathogenesis, and diagnosis of pulmonary hypertension

Pulmonary hypertension (PH) is a syndrome characterized by a persistent increase in pulmonary vascular resistance. Due to the lack of specificity in clinical manifestations, patients are usually diagnosed at the late stage of PH, which is hard to treat and often causes right heart failure and death. Furthermore, the regulation and pathogenesis of PH remain obscure. Recently, long noncoding RNAs (lncRNAs), a type of transcript longer than 200 nt that lacks protein-coding ability, have been found to substantially influence the incidence and progression of various diseases through regulating gene expression at the chromatin, transcriptional, post-transcriptional, translational, and even post-translational levels. The crucial roles of lncRNAs in PH have started to draw widespread attention. This review summarizes the regulatory, pathogenic, and diagnostic roles of lncRNAs in PH, in the hope to facilitate the search for early diagnostic markers of and effective therapeutic targets for this devastating disease.

Long noncoding RNA and mRNA expression profiles following igf3 knockdown in common carp, Cyprinus carpio

As a novel IGF system member, igf3 plays an important role in gonadal development of teleost fish. Although studies have reported the unusual expression of igf3 in fish gonad, whether the igf3 affects the expression of long noncoding RNAs (lncRNAs) in gonad remains unknown. In this study, an igf3 knockdown common carp (Cyprinus carpio) model was established by RNA interference. Then RNA sequencing of C. carpio gonad after igf3 knockdown was performed. A total of 327,169,410 and 306,305,018 clean reads were identified from control and igf3-dsRNA interference group, respectively. After a stringent filtering, RNA-seq yielded 14199 lncRNA and 106932 mRNA transcripts with 124 and 353 differentially expressed lncRNAs and mRNAs. Our dataset provides an extensive resource for understanding the potential regulatory molecular mechanism of igf3 in early stage of gonadal development in C. carpio.

Long non-coding RNA PSMB8-AS1 regulates influenza virus replication

Long non-coding RNAs (lncRNAs) are a new arm of gene regulatory mechanism as discovered by sequencing techniques and follow-up functional studies. There are only few studies on lncRNAs as related to gene expression regulation and anti-viral activity during influenza virus infection. We sought to identify and characterize lncRNAs involved in influenza virus replication. Using RNA sequencing analysis, we found that 1,912 lncRNAs were significantly changed in human lung epithelial A549 cells infected with influenza A/Puerto Rico/8/34. Gene ontology analysis on neighboring genes of these lncRNAs revealed that the genes involved in type I interferon signaling and cellular response were highly enriched. Seven selected up-regulated lncRNAs (AC015849.2, RP-1-7H24.1, PSMB8-AS1, CTD-2639E6.9, PSOR1C3, AC007283.5 and RP11-670E13.5) were verified by real-time PCR. These lncRNAs were also induced by other two influenza H1N1 virus strains (A/WSN/1933 and A/Oklahoma/3052/09) and interferon β1. Repression of PSMB8 antisense RNA 1 (PSMB8-AS1) using CRISPR interference reduced viral mRNA and protein levels as well as the release of progeny influenza virus particles. Our study suggests that lncRNA PSMB8-AS1 could be a new host factor target for developing antiviral therapy against influenza virus infection.

Long non-coding RNA activated by TGF-β expression in cancer prognosis: A meta-analysis

BACKGROUND

Recently, long non-coding RNA activated by transforming growth factor beta (TGF-β) (lncRNA ATB) was shown to be useful in cancer prognosis, however, its prognostic value in human cancer has been inconsistent. Our study aimed to explore the prognostic role of lncRNA ATB expression in cancer prognosis.

METHODS

PubMed, Embase, and Cochrane Library databases were thoroughly searched to retrieve studies focusing on the prognostic role of lncRNA ATB expression in cancer, and meta-analysis was performed.

RESULTS

A total of 15 studies were included into this meta-analysis. High lncRNA ATB expression was significantly related to shorter overall survival (OS) (HR = 2.44, 95%CI = 1.98-3.01, P < 0.01), recurrence-free survival (RFS) (HR = 1.85, 95%CI = 1.42-2.40, P < 0.01), disease-free survival (DFS) (HR = 3.61, 95%CI = 2.45-5.33, P < 0.01), and progression-free survival (PFS) (HR = 2.97, 95%CI = 2.12-4.16, P < 0.01) when compared with low lncRNA ATB expression in cancer. Moreover, Patients with high lncRNA ATB expression tended to have worse tumor differentiation (P < 0.01), more advanced clinical stage (P < 0.01), deeper tumor invasion (P < 0.01), earlier distant metastases (P = 0.02), lymph node metastases (P = 0.04), and vascular invasion (P < 0.01) when compared with those with low lncRNA ATB expression.

CONCLUSIONS

High lncRNA ATB expression was significantly associated with worse prognosis in cancer. LncRNA ATB expression could be used as a prognostic biomarker for human cancer.

Long non-coding RNA RAB11B-AS1 prevents osteosarcoma development and progression via its natural antisense transcript RAB11B

Long non-coding RNAs (lncRNAs) have been shown to exert essential roles in development and progression of tumors. Here we discovered a novel lncRNA, RAB11B antisense RNA (RAB11B-AS1), which is markedly down-regulated in human osteosarcoma (OS) and associated with OS metastasis and poor prognosis. We find that reduction of RAB11B-AS1 significantly facilitates proliferation, migration and invasiveness and prevents apoptosis of OS cells and results in lower sensitivity to cisplatin in these cells. In contrast, up-regulation of RAB11B-AS1 suppresses the aggressive behaviors of OS cells. Mechanistically, down-regulation of RAB11B-AS1 elevates its sense-cognate gene RAB11B expression at both mRNA and protein levels. RAB11B-AS1 expression correlates negatively with RAB11B expression in OS tissues. Luciferase reporter assay illuminated that RAB11B-AS1 regulates RAB11B expression through antisense pairing. Most importantly, all the effects of RAB11B-AS1 were abrogated by RAB11B down-regulation. Thus our findings revealed that lnc-RAB11B-AS1 prevents osteosarcoma development and progression via inhibiting RAB11B expression, indicating lnc-RAB11B-AS1 as a potential therapeutic target for osteosarcoma.

Long noncoding RNA TUG1 is a diagnostic factor in lung adenocarcinoma and suppresses apoptosis via epigenetic silencing of BAX

Lung cancer is one of the leading causes of cancer-related mortality, and responds badly to existing treatment. Thus, it is of urgent need to identify novel diagnostic markers and therapeutic targets. Increasing evidences have indicated that long non-coding RNAs (lncRNAs) play an important role in initiation and progression of lung cancer. However, the role of lncRNA Taurine upregulated 1 (TUG1) in lung adenocarcinoma (LAD) progression is not well known. In this study, we determined the diagnostic value of TUG1 in LAD patients, and further uncovered the underlying functional mechanism. Our results showed that TUG1 was significantly upregulated in LAD cells and serum samples. Receiver operator characteristic (ROC) analysis suggested a relatively higher area under the curve (AUC) of TUG1 (0.756) contrast to cyfra21-1 (0.619). In addition, high TUG1 level was associated with enhanced tumor size, degree of differentiation, lymph node metastases, distant metastasis and TNM stage. Cell functional assays showed that knockdown of TUG1 suppressed LAD cell viability and promoted cell apoptosis. We then sought to reveal the underlying regulatory mechanism, and the pro-apoptotic protein BAX was then identified as the downstream target of TUG1. Gain and loss functional assays showed that inhibition of BAX reversed the induced apoptosis by TUG1 knockdown. Finally, RNA immunoprecipitation and Chromatin immunoprecipitation revealed that TUG1 suppressed BAX expression through physically interacting with EZH2. In conclusion, lncRNA TUG1 is a promising diagnostic marker for LAD patients and suppression of TUG1 levels could be a future direction to promote the prognosis of LAD patients.

The role of miRNA and lncRNA in gastric cancer

Gastric cancer is one of the most common cancers and has the highest mortality rate worldwide. It is worthwhile to explore the mechanism of gastric cancer progression. An increasing number of studies have found that non-coding RNAs including miRNA and lncRNA play important roles in gastric cancer progression. This review summarized the role of ectopic miRNA in gastric cancer proliferation, growth, migration, invasion and apoptosis. Meantime, aberrantly expressed miRNA also received a great deal of attention as potential biomarker for gastric cancer diagnosis and therapy. Over the last decade, lncRNA was considered to regulate gastric cancer progression at the transcript and post-transcript level. At the transcript level, lncRNA induced gastric cancer progression by changing chromatin modification and mRNA stabilization to regulate mRNA and miRNA expression. Furthermore, lncRNA regulated gastric cancer progression by completely combining with miRNA to produce ceRNA or promote protein stabilization at the post-transcript level. Greater attention of miRNA and lncRNA in gastric cancer can provide new insight of mechanism of cancer development and may be acted as a new anticancer target.