Exosome-derived long non-coding RNA ADAMTS9-AS2 suppresses progression of oral submucous fibrosis via AKT signalling pathway

Oral submucosal fibrosis (OSF) is one of the pre-cancerous lesions of oral squamous cell carcinoma (OSCC). Its malignant rate is increasing, but the mechanism of malignancy is not clear. We previously have elucidated the long non-coding RNA (lncRNA) expression profile during OSF progression at the genome-wide level. However, the role of lncRNA ADAMTS9-AS2 in OSF progression via extracellular communication remains unclear. lncRNA ADAMTS9-AS2 is down-regulated in OSCC tissues compared with OSF and normal mucous tissues. Low ADAMTS9-AS2 expression is associated with poor overall survival. ADAMTS9-AS2 is frequently methylated in OSCC tissues, but not in normal oral mucous and OSF tissues, suggesting tumour-specific methylation. Functional studies reveal that exosomal ADAMTS9-AS2 suppresses OSCC cell growth, migration and invasion in vitro. Mechanistically, exosomal ADAMTS9-AS2 inhibits AKT signalling pathway and regulates epithelial-mesenchymal transition markers. Through profiling miRNA expression profile regulated by exosomal ADAMTS9-AS2, significantly enriched pathways include metabolic pathway, PI3K-Akt signalling pathway and pathways in cancer, indicating that exosomal ADAMTS9-AS2 exerts its functions through interacting with miRNAs during OSF progression. Thus, our findings highlight the crucial role of ADAMTS9-AS2 in the cell microenvironment during OSF carcinogenesis, which is expected to become a marker for early diagnosis of OSCC.     

Long noncoding RNA WDFY3-AS2 suppresses tumor progression by acting as a competing endogenous RNA of microRNA-18a in ovarian cancer

Ovarian cancer (OC) is a fatal cancer in women, mainly due to its aggressive nature and poor survival rate. The lncRNA-miRNA-mRNA (long noncoding RNA-microRNA-messenger RNA) interaction is promising biomarkers for the improving prognosis of OC. Therefore, we explored the regulatory mechanism of WDFY3-AS2/miR-18a/RORA axis involved in the biological activities of OC cells. Microarray analysis predicted differentially expressed lncRNA, miRNA, and mRNA related to OC, followed by investigating the relationship among them. The expression patterns of the identified lncRNA WDFY3-AS2, miR-18a, and RORA were measured in OC tissue and cells. Gain- and loss-of-function experiments were performed to characterize the effect of lncRNA WDFY3-AS2 on OC cells, as well as the involvement of miR-18a and RAR related orphan receptor A (RORA). The in vitro assays were validated by in vivo experiments. According to bioinformatics analysis, WDFY3-AS2 was speculated to affect OC by sponging miR-18a and modulating RORA. WDFY3-AS2 and RORA were underexpressed in OC, while miR-18a was highly expressed. Notably, WDFY3-AS2 acts as a competing endogenous RNA to sponge miR-18a and upregulate RORA. Upon overexpressing WDFY3-AS2 or inhibiting miR-18a, RORA expression was increased, thereby the OC cell proliferation, migration, invasion, and epithelial-to-mesenchymal transition (EMT) were suppressed, accompanied by enhanced apoptosis. In vivo experiments confirmed that the tumor growth was reduced in response to overexpressed WDFY3-AS2 or inhibited miR-18a. Taken together, the lncRNA WDFY3-AS2/miR-18a axis regulates the tumor progression of OC by targeting RORA, providing new insights for prevention and control of OC.     

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.     

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.     

METTL14 promotes tumorigenesis by regulating lncRNA OIP5-AS1/miR-98/ADAMTS8 signaling in papillary thyroid cancer

BackgroundPapillary thyroid cancer (PTC) is the most common type of cancer of the endocrine system. Long noncoding RNAs (lncRNAs) are emerging as a novel class of gene expression regulators associated with tumorigenesis. Through preexisting databases available for differentially expressed lncRNAs in PTC, we uncovered that lncRNA OIP5-AS1 was significantly upregulated in PTC tissues. However, the function and the underlying mechanism of OIP5-AS1 in PTC are poorly understood.MethodsExpression of lncRNA OIP5-AS1 and miR-98 in PTC tissue and cells were measured by quantitative real-time PCR (qRT-PCR). And expression of METTL14 and ADAMTS8 in PTC tissue and cells were measured by qRT-PCR and western blot. The biological functions of METTL14, OIP5-AS1, and ADAMTS8 were examined using MTT, colony formation, transwell, and wound healing assays in PTC cells. The relationship between METTL14 and OIP5-AS1 were evaluated using RNA immunoprecipitation (RIP) and RNA pull down assay. And the relationship between miR-98 and ADAMTS8 were examined by luciferase reporter assay. For in vivo experiments, a xenograft model was used to investigate the effects of OIP5-AS1 and ADAMTS8 in PTC.ResultsFunctional validation revealed that OIP5-AS1 overexpression promotes PTC cell proliferation, migration/invasion in vitro and in vivo, while OIP5-AS1 knockdown shows an opposite effect. Mechanistically, OIP5-AS1 acts as a target of miR-98, which activates ADAMTS8. OIP5-AS1 promotes PTC cell progression through miR-98/ADAMTS8 and EGFR, MEK/ERK pathways. Furthermore, RIP and RNA pull down assays identified OIP5-AS1 as the downstream target of METTL14. Overexpression of METTL14 suppresses PTC cell proliferation and migration/invasion through inhibiting OIP5-AS1 expression and regulating EGFR, MEK/ERK pathways.ConclusionsCollectively, our findings demonstrate that OIP5-AS1 is a METTL14-regulated lncRNA that plays an important role in PTC progression and offers new insights into the regulatory mechanisms underlying PTC development.Subject terms: Tumour biomarkers, Oncogenes     

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.     

LncRNA ADAMTS9-AS1 inhibits the stemness of lung adenocarcinoma cells by regulating miR-5009-3p/NPNT axis

We sought to extend our observation of LncRNA ADAMTS9-AS1 and to specifically uncover its role on the stemness of lung adenocarcinoma (LUAD) cancer cells. ADAMTS9-AS1 was poorly expressed in LUAD. The high ADAMTS9-AS1 expression was positively associated with overall survival. ADAMTS9-AS1 overexpression attenuated the colony-forming capacity and reduced stem cell-like population of LUAD cancer stem cells (CSCs). Furthermore, ADAMTS9-AS1 overexpression increased E-cadherin expression in addition to the downregulated expressions of Fibronectin and Vimentin in LUAD spheres. In vitro results also confirmed the ADAMTS9-AS1's inhibitory effect on the growth of LUAD cells. Moreover, the antagonistic repression of miR-5009-3p levels with the expression of ADAMTS9-AS1 and NPNT was confirmed. Finally, ADAMTS9-AS1 overexpression curbed the increasing stemness of LUDA-CSC caused by NPNT silencing, thus leading to the suppression of LUAD progression in vitro. Conclusively, ADAMTS9-AS1 negatively controls the LUAD cancer cell stemness progression through regulating miR-5009-3p/NPNT axis.     

LBX2-AS1 promotes ovarian cancer progression by facilitating E2F2 gene expression via miR-455-5p and miR-491-5p sponging

LBX2-AS1 is a long non-coding RNA that facilitates the development of gastrointestinal cancers and lung cancer, but its participation in ovarian cancer development remained uninvestigated. Clinical data retrieved from TCGA ovarian cancer database and the clinography of 60 ovarian cancer patients who received anti-cancer treatment in our facility were analysed. The overall cell growth, colony formation, migration, invasion, apoptosis and tumour formation on nude mice of ovarian cancer cells were evaluated before and after lentiviral-based LBX2-AS1 knockdown. ENCORI platform was used to explore LBX2-AS1-interacting microRNAs and target genes of the candidate microRNAs. Luciferase reporter gene assay and RNA pulldown assay were used to verify the putative miRNA-RNA interactions. Ovarian cancer tissue specimens showed significant higher LBX2-AS1 expression levels that non-cancerous counterparts. High expression level of LBX2-AS1 was significantly associated with reduced overall survival of patients. LBX2-AS1 knockdown significantly down-regulated the cell growth, colony formation, migration, invasion and tumour formation capacity of ovarian cancer cells and increased their apoptosis in vitro. LBX2-AS1 interacts with and thus inhibits the function of miR-455-5p and miR-491-5p, both of which restrained the expression of E2F2 gene in ovarian cancer cells via mRNA targeting. Transfection of miRNA inhibitors of these two miRNAs or forced expression of E2F2 counteracted the effect of LBX2-AS1 knockdown on ovarian cancer cells. LBX2-AS1 was a novel cancer-promoting lncRNA in ovarian cancer. This lncRNA increased the cell growth, survival, migration, invasion and tumour formation of ovarian cancer cells by inhibiting miR-455-5p and miR-491-5p, thus liberating the expression of E2F2 cancer-promoting gene.     

Long non-coding RNA OIP5-AS1 promotes pancreatic cancer cell growth through sponging miR-342-3p via AKT/ERK signaling pathway

Opa-interacting protein 5 antisense RNA 1 (OIP5-AS1), a long non-coding RNA (lncRNA), has been reported to link with the progression of some cancers. However, its biological functions and underlying molecular mechanisms in pancreatic cancer are largely unknown. The aim of this study was to investigate the role of lncRNA OIP5-AS1 in pancreatic cancer. Quantitative real-time PCR analysis revealed that OIP5-AS1 is highly expressed in pancreatic cancer tissues versus adjacent non-tumor tissues. In vitro functional assays showed that downregulation of OIP5-AS1 or overexpression of miR-342-3p inhibited the proliferation, decreased Ki67 expression, and induced cell cycle arrest in pancreatic cancer cells. The expression of cyclinD1, CDK4, and CDK6 was decreased by knockdown of OIP5-AS1. Moreover, we found that OIP5-AS1 acted as a miR-342-3p sponge to suppress its expression and function. Dual-luciferase assay confirmed the interaction of OIP5-AS1 and miR-342-3p and verified anterior gradient 2 (AGR2) as a direct target of miR-342-3p. Results showed that depletion of miR-342-3p abolished the inhibitory effects of OIP5-AS1 knockdown on pancreatic cancer cell growth. The expression of Ki67, AGR2, cyclinD1, CDK4, CDK6, p-AKT, and p-ERK1/2 was reversed by silencing of miR-342-3p in pancreatic cancer cells with OIP5-AS1 knockdown. Further, knockdown of OIP5-AS1 suppressed tumor growth in a xenograft mouse model of pancreatic cancer. OIP5-AS1 induced pancreatic cancer progression via activation of AKT and ERK signaling pathways. Therefore, we demonstrate that OIP5-AS1 functions as oncogene in pancreatic cancer and its downregulation inhibits pancreatic cancer growth by sponging miR-342-3p via targeting AGR2 through inhibiting AKT/ERK signaling pathway.

     

Identification of lncRNA–miRNA–mRNA regulatory network associated with epithelial ovarian cancer cisplatin-resistant

To construct a long noncoding RNA (lncRNA)–microRNA (miRNA)–messenger RNA (mRNA) regulatory network related to epithelial ovarian cancer (EOC) cisplatin-resistant, differentially expressed genes (DEGs), differentially expressed lncRNAs (DELs), and differentially expressed miRNAs (DEMs) between MDAH and TOV-112D cells lines were identified. Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were conducted to analyze the biological functions of DEGs. Downstream mRNAs or upstream lncRNAs for miRNAs were analyzed at miRTarBase 7.0 or DIANA-LncBase V2, respectively. A total of 485 significant DEGs, 85 DELs, and 5 DEMs were identified. Protein–protein interaction (PPI) network of DEGs contrains 81 nodes and 141 edges was constructed, and 25 hub genes related to EOC cisplatin-resistant were identified. Subsequently, a lncRNA–miRNA–mRNA regulatory network contains 4 lncRNAs, 4 miRNAs, and 35 mRNAs was established. Taken together, our study provided evidence concerning the alteration genes involved in EOC cisplatin-resistant, which will help to unravel the mechanisms underlying drug resistant.     

The lncRNA ELF3-AS1 promotes bladder cancer progression by interaction with Krüppel-like factor 8

Accumulating evidence has shown the critical role of long non-coding RNAs (lncRNAs) during cancer progression. However, the involvement of ELF3-AS1 in bladder cancer (BC) remains largely unclear. By lncRNA profiling, we identified ELF3-AS1 as a novel oncogenic lncRNA during bladder cancer development. ELF3-AS1 was highly expressed in bladder cancer and correlated with poor prognosis. ELF3-AS1 could increase viability and migration of bladder cancer cells in vitro and promoted xenograft tumor growth in vivo. Furthermore, ELF3-AS1 could interact with KLF8 to stabilize KLF8 by protecting it from proteasome-mediated degradation. KLF8 in turn could bind ELF3-AS1 promoter and transactivate ELF3-AS1 expression. The positive feedback loop between ELF3-AS1 and KLF8 enhanced KLF8 signaling by increasing MMP9 expression. Collectively, our study has unraveled a novel mechanism of ELF3-AS1-mediated oncogenesis in bladder cancer by reinforcement of ELF3-AS1/KLF8 signaling with potential implications for therapeutic intervention.     

LncRNA OIP5-AS1-directed miR-7 degradation promotes MYMX production during human myogenesis

Long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) modulate gene expression programs in physiology and disease. Here, we report a noncoding RNA regulatory network that modulates myoblast fusion into multinucleated myotubes, a process that occurs during muscle development and muscle regeneration after injury. In early stages of human myogenesis, the levels of lncRNA OIP5-AS1 increased, while the levels of miR-7 decreased. Moreover, OIP5-AS1 bound and induced miR-7 decay via target RNA-directed miRNA decay; accordingly, loss of OIP5-AS1 attenuated, while antagonizing miR-7 accelerated, myotube formation. We found that the OIP5-AS1-mediated miR-7 degradation promoted myoblast fusion, as it derepressed the miR-7 target MYMX mRNA, which encodes the fusogenic protein myomixer (MYMX). Remarkably, an oligonucleotide site blocker interfered with the OIP5-AS1-directed miR-7 degradation, allowing miR-7 to accumulate, lowering MYMX production and suppressing myotube formation. These results highlight a mechanism whereby lncRNA OIP5-AS1-mediated miR-7 decay promotes myotube formation by stimulating a myogenic fusion program.     

AGAP2-AS1 serves as an oncogenic lncRNA and prognostic biomarker in glioblastoma multiforme

Long noncoding RNA (lncRNA) AGAP2 antisense RNA 1 (AGAP2-AS1) has been suggested to function as an oncogenic lncRNA in lung cancer, breast cancer, and anaplastic glioma. However, the expression pattern and molecular mechanism of AGAP2-AS1 in glioblastoma multiforme (GBM) remains unknown. The purpose of this study is to present more evidence about the clinical and biological function of AGAP2-AS1 in GBM. In our results, we found AGAP2-AS1 expression was increased in GBM compared with adjacent normal brain tissues or low-grade glioma tissues, and there was no significantly different between low-grade glioma tissues and normal tissues. Kaplan-Meier survival analysis indicated patients with GBM having high-expression of AGAP2-AS1 had shorter overall survival time than those with low expression of AGAP2-AS1. The loss-of-function studies showed that downregulation of AGAP2-AS1 depressed cell proliferation, migration, and invasion, and promoted cell apoptosis in GBM. In summary, AGAP2-AS1 is a prognostic biomarker for patients with GBM, and functions as an oncogenic lncRNA to modulate GBM cell proliferation, apoptosis, migration, and invasion, which suggests that AGAP2-AS1 is potential therapeutic target for GBM.     

LncRNA PDCD4-AS1 alleviates triple negative breast cancer by increasing expression of IQGAP2 via miR-10b-5p

ObjectiveMounting evidence demonstrates that long non-coding RNA (lncRNA) is dysregulated in breast cancers. This study was designed to detect the influences and regulatory mechanism of lncRNA PDCD4-AS1 in triple-negative breast cancer (TNBC).MethodsqRT-PCR and Western blot were utilized to investigate the expression levels of PDCD4-AS1, miR-10b-5p and IQGAP2 in TNBC tissues and cells. Online software and luciferase reporter gene system were employed to testify the interactions among these molecules. Loss and gain of function of PDCD4-AS1, miR-10b-5p or IQGAP2 were performed before MTT and colony formation assay, TUNEL staining in addition to Transwell and scratch assays were applied to measure the cell biological functions.ResultsIn this work, PDCD4-AS1 and IQGAP2 were lowly expressed while miR-10b-5p was strongly expressed in TNBC tissues and cells. PDCD4-AS1 or IQGAP2 overexpression effectively attenuated TNBC cell proliferation, migration and invasion, and increased the apoptosis rate, while this effect was abandoned in response to miR-10b-5p mimics transfection. miR-10b-5p bound to IQGAP2 and acted as a downstream target of PDCD4-AS1.ConclusionOur findings identified lncRNA PDCD4-AS1 as a tumor suppressor in TNBC by regulating IQGAP2 expression via miR-10b-5p, giving a novel insight into the regulatory mechanism of PDCD4-AS1 in the pathogenesis of TNBC.     

Microarray expression profiles analysis revealed lncRNA OXCT1-AS1 promoted bladder cancer cell aggressiveness via miR-455-5p/JAK1 signaling

Bladder cancer (BCa) is one of the most prevalent cancers of the urinary system worldwide. Accumulating evidence suggests that long noncoding RNAs (lncRNAs) perform a vital function in the pathogenesis and progression of BCa. In the current study, we identified a novel lncRNA OXCT1-AS1 and investigated its role and potential mechanisms in BCa. The microarray results showed the expression of lncRNAs, microRNAs, and messenger RNAs between BCa primary tumor tissues and metastatic lymph nodes were significantly different. The quantitative polymerase chain reaction verification was performed to ensure the reliability of the screening results. The Cell Counting Kit 8 and transwell assay were used to assess the tumor cell proliferation and invasion abilities in vitro, respectively. The dual-luciferase activity assay was performed to investigate the potential mechanism of competing endogenous RNA network. lncRNA OXCT1-AS1, which elevated in metastasis lymph node, was significantly upregulated in BCa cell lines compared with SVHUC-1. We demonstrated OXCT1-AS1 inhibited miR-455-5p to decrease its binding to the JAK1 3′-untranslated region, which could upregulate the expression of JAK1 at the protein level, thus promoting BCa proliferation and invasion. Therefore, lncRNA OXCT1-AS1 could act as a potential biomarker and therapeutic target for patients with BCa.