Aberrant lncRNA Expression Research Articles

H19/TET1 axis promotes TGF-β signaling linked to endothelial-to-mesenchymal transition.

While emerging evidence suggests the link between endothelial activation of TGF‐β signaling, induction of endothelial‐to‐mesenchymal transition (EndMT), and cardiovascular disease (CVD), the molecular underpinning of this connection remains enigmatic. Here, we report aberrant expression of H19 lncRNA and TET1 in endothelial cells (ECs) of human atherosclerotic coronary arteries. Using primary human umbilical vein endothelial cells (HUVECs) and aortic endothelial cells (HAoECs) we show that TNF‐α, a known risk factor for endothelial dysfunction and CVD, induces H19 expression which in turn activates TGF‐β signaling and EndMT via a TET1‐dependent epigenetic mechanism. We also show that H19 regulates TET1 expression at the posttranscriptional level. Further, we provide evidence that this H19/TET1‐mediated regulation of TGF‐β signaling and EndMT occurs in mouse pulmonary microvascular ECs in vivo under hyperglycemic conditions. We propose that endothelial activation of the H19/TET1 axis may play an important role in EndMT and perhaps CVD.

Role of long non-coding RNAs (LncRNAs) in multiple sclerosis: a brief review.

Multiple sclerosis (MS) as chronic autoimmune inflammatory neurological disease of the central nervous system (CNS) occurs due to several environmental and genetic factors, whose pathogenesis is associated with genes with regulatory role in the immune system. Long non-coding RNAs (LncRNAs) are able to reportedly regulate responses of immune systems and expression of genes, and show the tissue specificity and complexity of biofunctions. Various studies have suggested that the aberrant LncRNA expression is an underlying factor involved in the incidence of MS and that the analysis of the expression profile of these molecules can be a specific biomarker of MS for preventing the course of the disease or responding to treatment. The purpose of this research was to review the recent studies for exploring the functions of LncRNAs in the processes leading to MS disease.

Long Non-Coding RNAs in Biliary Tract Cancer-An Up-to-Date Review.

The term long non-coding RNA (lncRNA) describes non protein-coding transcripts with a length greater than 200 base pairs. The ongoing discovery, characterization and functional categorization of lncRNAs has led to a better understanding of the involvement of lncRNAs in diverse biological and pathological processes including cancer. Aberrant expression of specific lncRNA species was demonstrated in various cancer types and associated with unfavorable clinical characteristics. Recent studies suggest that lncRNAs are also involved in the development and progression of biliary tract cancer, a rare disease with high mortality and limited therapeutic options. In this review, we summarize current findings regarding the manifold roles of lncRNAs in biliary tract cancer and give an overview of the clinical and molecular consequences of aberrant lncRNA expression as well as of underlying regulatory functions of selected lncRNA species in the context of biliary tract cancer.

Competing endogenous RNA network analysis reveals potential long non-coding RNAs as predictive biomarkers of gastric cancer.

Gastric cancer (GC) is one of the most frequently occurring life-threatening malignancies worldwide. Due to its high mortality rate, the discovery of putative biomarkers that may be sensitive and specific to GC is of seminal importance. Long non-coding RNAs (lncRNAs) are non-translatable RNAs whose transcript length exceeds 200 base pairs. The dysregulation of lncRNA expression plays a key role in tumorigenesis and development. In the present study, the expression profiles of lncRNAs, microRNAs and mRNAs of 361 GC tissues (and 32 normal gastric tissues) were downloaded from The Cancer Genome Atlas database. Furthermore, differentially expressed RNAs were analyzed by the DEseq package. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses confirmed some significant dysregulated signaling pathways and target RNAs. As a result, an lncRNA-associated competing endogenous RNA (ceRNA) network was constructed. Kaplan-Meier analysis of the differentially expressed RNAs associated with GC pathogenesis confirmed that the lncRNAs PVT1, HAND2-AS1 and ZNF667-AS1 were potentially associated with the prognosis of GC (P<0.05). The present study suggests the mechanism of ceRNA networks in GC, and further demonstrates that aberrant lncRNA expression may be used as an effective diagnostic tool (or target) for the prognosis of GC.

Aberrant LncRNA Expression in Leukemia.

Leukemia is a common malignant cancer of the hematopoietic system, whose pathogenesis has not been fully elucidated. Long noncoding RNAs (lncRNAs) are transcripts longer than 200 nucleotides without protein-coding function. Recent studies report their role in cellular processes such as the regulation of gene expression, as well as in the carcinogenesis, occurrence, development, and prognosis of various tumors. Evidence indicating relationships between a variety of lncRNAs and leukemia pathophysiology has increased dramatically in the previous decade, with specific lncRNAs expected to serve as diagnostic biomarkers, novel therapeutic targets, and predictors of clinical outcomes. Furthermore, these lncRNAs might offer insight into disease pathogenesis and novel treatment options. This review summarizes progress in studies on the role(s) of lncRNAs in leukemia.

Hottip Lncrna Reinforces CTCF Defined Chromatin Boundaries and Drives Wnt Target Gene Expression in AML Leukemogenesis

We reported recently that HOXA locus associated lncRNA, HOTTIP, is highly expressed in AML patients carrying MLL rearrangement and NPM1c+ mutations. The expression of HOTTIP positively correlates with posterior HOXA gene expression and poor patient survival. We further demonstrated that HOTTIP acts as an epigenetic regulator to define oncogenic HOXA topologically associated domain (TAD) and drive HOXA associated leukemic transcription program. However, it remains unclear whether and how HOTTIP lncRNA is involved in remodeling leukemic genome to facilitate AML leukemogenesis. Here, we showed that HOTTIP regulates a fraction of CTCF binding sites (CBSs) in the AML genome by directly interacting with CTCF and its binding motifs. We carried out CTCF ChIP-seq and HOTTIP ChIRP (chromatin isolation by RNA purification)-seq comparing WT and HOTTIP knockout (KO) MOLM13 cells. KO of HOTTIP in MLL-rearranged MOLM13 AML cells specifically impaired CTCF binding sites that were co-occupied by HOTTIP lncRNA, whereas loss of HOTTIP did not affect global CTCF binding. These target genes include posterior HOXA genes and Wnt target genes such as C-MYC, EVI1, AXIN, and TWIST1. Furthermore, we found that HOTTIP interacts with its putative target sites by formation of DNA: RNA hybridization structure triple helix and R-loop in vivo and in vitro. We then carried out DRIP (DNA-RNA immunoprecipitation)-seq and DRIPc(DNA-RNA immunoprecipitation followed by cDNA conversion)-Seq, which utilize a sequence independent but structure-specific S9.6 antibody for DRIP to capture global R-loops, by comparing WT and HOTTIP KO MOLM13 cells. The obtained DRIP-seq and DRIPc-seq data were then incorporated and integrated with the HOTTIP ChIRP-seq and CTCF ChIP-seq data to explore global collaboration between R-loop and HOTTIP associated CTCF binding sites. We found that HOTTIP interacts with CTCF binding motif that defines the TADs and the promoters of the HOTTIP target genes by formation of R-loop or triple helix structure. Loss of HOTTIP disrupted the R-loop formation at promoters and enhancers of the HOTTIP target genes to inhibit their expression. In MLL-rearranged AML genome, in addition to the HOXA locus, CTCF forms leukemic specific TADs that protect aberrant Wnt target genes. Depletion of HOTTIP lncRNA impaired CTCF defined TADs in the Wnt target gene loci and reduced Wnt target gene expression. In contrast, overexpression of Hottip lncRNA (Hottip-Tg) in the mice bone marrow hematopoietic compartment perturbs hematopoietic stem cell (HSC) self-renewal and differentiation leading to AML like disease by reinforcing CTCF defined TADs, enhancing chromatin accessibility within TADs, and upregulating gene transcription in the Wnt target loci. Finally, when we treated HOTTIP expressed primary patient AML cells carrying MLL-rearrangement and their derived PDX mouse model with a canonical Wnt inhibitor, ICG-001, ICG-001 inhibited AML LSC self-renewal in in vitro by LTC-IC assays and in vivo leukemogenesis in the PDX mouse models with an aberrant HOTTIP lncRNA expression, but not in HOTTIP negative/low non-MLL AML samples. Thus, HOTTIP lncRNA and CTCF cooperate to specifically reinforce CTCF defined WNT target locus TADs and drive Wnt target gene expression in the HOTTIP expressed AML. Disclosures No relevant conflicts of interest to declare.

Low expression of long noncoding RNA CTC-297N7.9 predicts poor prognosis in patients with hepatocellular carcinoma.

BackgroundLong noncoding RNAs (lncRNAs) are reported to play important roles in tumorigenesis of various malignant tumors. However, the clinical significance of aberrant lncRNA expression in hepatocellular carcinoma (HCC) is still elusive.MethodsFirstly, a differentially expressed lncRNA CTC‐297N7.9 in HCC was detected by analyzing the data from The Cancer Genome Atlas (TCGA). Secondly, the expression level of CTC‐297N7.9 was examined in four HCC cell lines and 60 pairs of HCC tissues by polymerase chain reaction (PCR) assay at our center. Thirdly, receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic value of CTC‐297N7.9 for HCC. Correlation and survival analysis of HCC patients from the TCGA and our center were also carried out to assess the predictive value of CTC‐297N7.9. Finally, survival prognostic models were established combining lncRNA expression and other clinical parameters.ResultsThe expression of CTC‐297N7.9 was downregulated in HCC cell lines and HCC tissues. ROC curve revealed its significant diagnostic value in HCC. CTC‐297N7.9 expression correlated with serum alpha‐fetal protein (AFP), tumor stage, and tumor differentiation. Survival analysis indicated that overall survival (OS) and disease‐free survival (DFS) are all positively associated with CTC‐297N7.9 expression, especially in patients without viral hepatitis or cirrhosis. Cox regression analysis showed that CTC‐297N7.9 expression level is an independent prognostic factor for both OS and DFS in HCC patients. Based on the model, CTC‐297N7.9 was observed to be negatively correlated to risk score, indicating its role as a protective factor for HCC.ConclusionOur study demonstrated that the low expression of CTC‐297N7.9 is associated with poor prognosis in HCC patients, suggesting its possible role as a potential prognostic marker for HCC.

LncRNA-241 inhibits 1,2-Dichloroethane-induced hepatic apoptosis

Chlorinated organic chemical 1,2-dichloroethane (1,2-DCE) is used widely in industrial production processes, and excessive exposure may lead to liver damage. The mechanisms underlying 1,2-DCE-induced hepatotoxicity are not fully understood. Numerous studies have demonstrated that long-non-coding RNAs (lncRNAs) play a pivotal role in the chemical-induced toxicity. To explore whether aberrant lncRNA expression is involved in hepatotoxicity mediated by 1,2-DCE exposure, we detected alterations of lncRNA expression profiling in a mouse model of 1,2-DCE-induced hepatotoxicity by microarray chip. Bioinformatic analysis indicated that a down-regulated lncRNA (lncRNA241) after 1,2-DCE exposure might be involved in 1,2-DCE-induced hepatotoxicity. We treated AML12 cells with 1,2-DCE and its metabolite 2-chloroacetic acid (2-CA) for 48 h, and the results revealed that it was 2-CA rather than primary form (1,2-DCE) that resulted in the decline of lncRNA241 expression in hepatocytes. In vitro intervention studies revealed that the repression of lncRNA241 expression after 2-CA exposure led to the down-regulation of anti-apoptosis-associated factor insulin growth factor-1 (Igf1) at mRNA and protein levels through modulation of their common target mmu-miR-451a, which promoted hepatic apoptosis. This study provides valuable insight into the role of lncRNAs in response to hepatocyte apoptosis induced by 1,2-DCE.

Expression of several long noncoding RNAs in peripheral blood mononuclear cells of patients with systemic lupus erythematosus

PurposeAccumulating evidence has linked long noncoding RNAs (lncRNAs) to autoimmune and inflammatory disorders. This study aimed to detect the expression levels of five lncRNAs (lnc0640, lnc3643, lnc5150, lnc7514 and lncagf) in peripheral blood mononuclear cells (PBMCs) of patients with systemic lupus erythematosus (SLE), as well as their correlation with clinical and laboratory features. Materials/methodsWe recruited 76 patients with SLE and 71 normal controls into the present study, and obtained PBMCs from the blood samples of all study subjects. Expression levels of lncRNAs were determined by quantitative real-time reverse transcription polymerase chain reaction and their associations with clinical and laboratory characteristics were analyzed. ResultsLnc5150 expression levels were statistically significantly decreased (Z=−6.016, P < 0.001) compared with normal controls. Lnc3643 levels were also statistically significantly decreased in SLE patients with proteinuria compared with those without (Z=−2.934, P = 0.003), and the lnc7514 levels were statistically significantly lower in anti-dsDNA(+) patients compared with anti-dsDNA(-) patients. The expression levels of lnc3643 were correlated with C-reactive protein and erythrocyte sedimentation rate (ESR), lnc7514 was correlated with disease activity and ESR (all P < 0.01). ConclusionsThe aberrant lncRNA expression levels and their associations with laboratory features in SLE suggest their important role in SLE pathogenesis.

The role of lncRNA RP11-154D6 in steroid-induced osteonecrosis of the femoral head through BMSC regulation.

Bone marrow stem cells (BMSCs) are involved in steroid-induced osteonecrosis of the femoral head (ONFH). Long noncoding RNAs (lncRNAs) have been demonstrated to regulate functions of BMSCs, especially their differentiation, and have been reported to be implicated in diverse bone disorders. However, the roles of lncRNAs in the progression of steroid-induced ONFH remain unknown. BMSCs were isolated from healthy controls or patients with steroid-induced ONFH. RNA-sequencing was used to identify differentially expressed (DE) coding and noncoding transcripts and a lncRNA-messenger RNA coexpression network were created. The function of lncRNA RP11-154D6 in the proliferation, apoptosis, and differentiation of BMSCs was identified by overexpressing or silencing its expression. Altogether, 3114 DE messenger RNAs and 572 DE lncRNAs were identified and the expression of lncRNA RP11-154D6 was significantly decreased in BMSCs of patients with ONFH. Although no effects on proliferation and apoptosis were identified, we proved lncRNA RP11-154D6 promoted osteogenic differentiation while inhibiting adipogenic differentiation in BMSCs. Aberrant expression of lncRNA was identified in BMSCs of steroid-induced patients with ONFH. Our results demonstrated that lncRNA RP11-154D6 might contribute to the progression of steroid-induced ONFH through regulating the behavior of BMSCs and might provide new insights into the pathogenesis as well as treatment for steroid-induced ONFH.

Long non-coding RNA 00152 promotes cell proliferation in cervical cancer via regulating miR-216b-5p/HOXA1 axis.

Several studies demonstrated that aberrant lncRNA expression contributes to cervical cancer (CC) development and progression. LINC00152, a novel lncRNA, has been identified as an oncogene involved in various cancers. In the present study, we aim to investigate the expression pattern, clinical significance, potential functional roles, and regulatory mechanism of LINC00152 in CC. The transcription levels of LINC00152, miR-216b-5p, and HOXA1 in CC tissues and cell lines were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). LINC00152 knockdown in CC cells was conducted by transfecting the LINC00152-specific siRNA. The cell proliferation ability was evaluated by the Cell Counting Kit-8 (CCK-8) assay. Cell cycle and apoptosis analysis were assessed by flow cytometry. The target relation among LINC00152, miR-216b-5p, and HOXA1 were measured using the dual-luciferase reporter assay. The protein levels of HOXA1 in CC cells were determined by Western blot. LINC00152 was up-regulated in CC tissues and cell lines. The high expression level of LINC00152 was positively correlated with poor prognosis and histologic grade in CC. The silence of LINC00152 could inhibit the proliferation of CC cells through inducing the cell cycle arrest at G0/G1 phase and promote apoptosis in vitro. Mechanically, we demonstrated that LINC00152 could modulate the proliferation of CC cells through elevating HOXA1 expression level via sponging miR-216b-5p based on bioinformatics analysis and experimental validation. Our findings revealed a novel molecular mechanism underlying LINC00152 modulating CC progression through the miR-216b-5p/HOXA1 pathway, suggesting that LINC00152 might potentially act as an effective diagnostic marker and therapeutic target for cervical cancer.

Emerging roles of long non-coding RNA in cancer.

Since comprehensive analysis of the mammalian genome revealed that the majority of genomic products are transcribed in long non‐coding RNA (lncRNA), increasing attention has been paid to these transcripts. The applied next‐generation sequencing technologies have provided accumulating evidence of dysregulated lncRNA in cancer. The implication of this finding can be seen in many forms and at multiple levels. With impacts ranging from integrating chromatin remodeling complexes to regulating transcription and post‐transcriptional processes, aberrant expression of lncRNA may have repercussions in cell proliferation, tumor progression or metastasis. lncRNA may act as enhancers, scaffolds or decoys by physically interacting with other RNA species or proteins, resulting in a direct impact on cell signaling cascades. Even though their functional classification is well‐established in the context of cancer, clearer characterization in terms of their phenotypic outputs is needed to optimize and identify suitable candidates that enable the development of new therapeutic strategies and the design of novel diagnostic approaches. The present article aims to outline different cancer‐associated lncRNA according to their contribution to tumor suppression or tumor promotion based on their most current functional annotations.

Aberrant lncRNA Expression in Multiple Myeloma.

Multiple myeloma (MM), a type of malignant tumor, is characterized by dysplasia of clonal plasma cells in the bone marrow. People with MM will have damaged organs or tissues due to secretion of large amounts of monoclonal immunoglobulin or fragments (M protein). Despite improved survivability by novel treatment strategies over the last decade, MM is still incurable by current therapies. Long noncoding RNAs (lncRNAs), with length of more than 200 nucleotides, have been reported to act as important regulators in many diseases, including MM. Recent studies have reported aberrant lncRNA expression in MM; these dysregulated lncRNAs can play oncogenic and/or tumor-suppressive roles in the development and progression of MM. In this article, we present a general overview on the role of lncRNAs in MM pathogenesis and discuss their potential as prognostic biomarkers and targets for treatment.

The effects of aberrant expression of LncRNA DGCR5/miR‐873‐5p/TUSC3 in lung cancer cell progression

Lung cancer is the most common cause of cancer‐related mortality worldwide, and nonsmall cell lung cancer (NSCLC) accounts for 80% of all pulmonary carcinomas. Recently, long noncoding RNAs (lncRNAs) have been paid attention for exploring treatment of various diseases. Upregulation of DiGeorge syndrome critical region gene 5 (DGCR5) predicts better lung squamous cell carcinoma prognosis; therefore, we explore the role of DGCR5 in lung cancer in our present study. Consecutive patients with LC were treated in our hospital between January 2015 and January 2016. qRT‐PCR demonstrated that DGCR5 was significantly lower in neoplastic tissues than in non‐neoplastic tissues. For in vitro experiments, cell growth, migration, and invasion were significantly lower in A549 cells transfected with pcDNA3.1‐DGCR5 than pcDNA3.1, which were verified by 5‐diphenyltetrazolium bromide (MTT) assay, scratch test, and transwell assay, respectively, with no significant induction on cell apoptosis that was demonstrated by flow cytometry (FCM) assay. Bioinformatics analysis predicted that 3’ untranslated region (UTR) of tumor suppressor candidate 3 (TUSC3, 49‐55 bp) and DGCR5 (801‐807 bp) shared a common hsa‐miR‐873‐5p binding site, and the direct interaction between DGCR5 and hsa‐miR‐873‐5p or hsa‐miR‐873‐5p and TUSC3 was verified by dual‐luciferase reporter assay. qRT‐PCR demonstrated that hsa‐miR‐873‐5p was dramatically higher and TUSC3 was significantly lower in neoplastic tissues than in non‐neoplastic tissues. DGCR5 decreased the protein level of TUSC3 by miR‐873‐5p which was demonstrated by Western blot and immunofluorescence. The role of DGCR5 in tumorigenesis in vivo was consistent with in vitro assays, Ki‐67‐positive cell number (exhibited by immunohistochemical staining), tumor size, and tumor weight of A549‐DGCR5 group were significantly lower in comparison with A549‐control group.

Long non-coding RNA and Polycomb: an intricate partnership in cancer biology.

High-throughput analyses have revealed that the vast majority of the transcriptome does not code for proteins. These non-translated transcripts, when larger than 200 nucleotides, are termed long non-coding RNAs (lncRNAs), and play fundamental roles in diverse cellular processes. LncRNAs are subject to dynamic chemical modification, adding another layer of complexity to our understanding of the potential roles that lncRNAs play in health and disease. Many lncRNAs regulate transcriptional programs by influencing the epigenetic state through direct interactions with chromatin-modifying proteins. Among these proteins, Polycomb repressive complexes 1 and 2 (PRC1 and PRC2) have been shown to be recruited by lncRNAs to silence target genes. Aberrant expression, deficiency or mutation of both lncRNA and Polycomb have been associated with numerous human diseases, including cancer. In this review, we have highlighted recent findings regarding the concerted mechanism of action of Polycomb group proteins (PcG), acting together with some classically defined lncRNAs including X-inactive specific transcript (XIST), antisense non-coding RNA in the INK4 locus (ANRIL), metastasis associated lung adenocarcinoma transcript 1 (MALAT1), and HOX transcript antisense RNA (HOTAIR).

Forging our understanding of lncRNAs in the brain

During both development and adulthood, the human brain expresses many thousands of long noncoding RNAs (lncRNAs), and aberrant lncRNA expression has been associated with a wide range of neurological diseases. Although the biological significance of most lncRNAs remains to be discovered, it is now clear that certain lncRNAs carry out important functions in neurodevelopment, neural cell function, and perhaps even diseases of the human brain. Given the relatively inclusive definition of lncRNAs-transcripts longer than 200 nucleotides with essentially no protein coding potential-this class of noncoding transcript is both large and very diverse. Furthermore, emerging data indicate that lncRNA genes can act via multiple, non-mutually exclusive molecular mechanisms, and specific functions are difficult to predict from lncRNA expression or sequence alone. Thus, the different experimental approaches used to explore the role of a lncRNA might each shed light upon distinct facets of its overall molecular mechanism, and combining multiple approaches may be necessary to fully illuminate the function of any particular lncRNA. To understand how lncRNAs affect brain development and neurological disease, in vivo studies of lncRNA function are required. Thus, in this review, we focus our discussion upon a small set of neural lncRNAs that have been experimentally manipulated in mice. Together, these examples illustrate how studies of individual lncRNAs using multiple experimental approaches can help reveal the richness and complexity of lncRNA function in both neurodevelopment and diseases of the brain.

Abstract 3448: LncRNA HAND2-AS1 inactivates neuromedin U (NMU) and inhibits tumor invasion and metastasis in endometrioid endometrial carcinoma

Abstract Background Endometrioid endometrial carcinoma (EEC) is one of the common cause of cancer-related mortality in women. Despite progress in diagnostics and treatment of EEC, its prognosis remains poor. Mounting evidence suggest that long noncoding RNAs (lncRNAs) function in mutiple human cancers. Aberrant lncRNA expression may predict tumor outcome of patients and have served as diagnostic or prognostic markers. In this study, we investigated the expression levels and functions of lncRNAs in EEC. Methods Differentially expressed lncRNAs involved in EEC were identified by using publically available RNA-Seq data. The expression of 18 dysregulated lncRNA candidates was verified in 5 NE tissues, 5 EEC tissues and 5 EEC cell lines (HEC1-A, HEC1-B, AN3CA, KLE and RL95-2) by real-time polymerase chain reaction (PCR). Further, we selected the most misexpressed lncRNA and confirmed the expression level of the lncRNA in 59 EEC tissues and 24 NE tissues by real-time PCR and correlated the lncRNA expression levels with the clinical pathological characteristics. The promoter methylation assay was used to analyze the methylation level of the lncRNA in EEC. The lncRNA methylation status was confirmed by bisulfite genomic sequencing. Cell proliferation assays, wound healing assays, and invasion and migration assays were performed to determine the biological functions of the lncRNA in EEC cells. To discover the direct targets of the lncRNA in EEC, we performed RNA-sequence analysis in EEC cells overexpressed with the lncRNA and target genes were further studied by functional studies in vitro (knockdown assay and overexpression rescue assay). Results We discovered that HAND2-AS1, a lncRNA transcribed antisense adjacent to Heart and Neural Crest Derivatives Expressed 2 (HAND2), was significantly downregulated lncRNA in EEC. HAND2-AS1 and HAND2 was frequently downregulated in EEC tissues, especially in poor differentiated tumor tissues. Downregulation of HAND2-AS1 and HAND2 was correlated with tumor grade, lymph node metastasis and recurrence of EEC patients. HAND2-AS1 and HAND2 was co-downregulated by promoter hypermethylation in EEC. HAND2-AS1 suppressed EEC cell migration and invasion but not cell growth. Similarly, HAND2 also inhibited EEC cell migration and invasion indicating that HAND2-AS1 and HAND2 have a concordant role in the progression of EEC. Moreover, the anti-tumorigenic effect of HAND2-AS1 was mediated by downregulating NMU, which had an oncogenic role in EEC. Conclusions Our findings provide the first evidence that HAND2-AS1 is a critical tumor suppressor in EEC and may constitute a prognostic biomarker in EEC. Note: This abstract was not presented at the meeting. Citation Format: Xueying Yang, Yu Zhao, Kun Sun, Yuying Li, Jiajian Zhou, Jianzhang Wang, Hao Sun, Chi Chiu Wang, Joseph Kwong, Huating Wang, Tony Kwok Hung Chung. LncRNA HAND2-AS1 inactivates neuromedin U (NMU) and inhibits tumor invasion and metastasis in endometrioid endometrial carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3448. doi:10.1158/1538-7445.AM2017-3448

A potential panel of two-long non-coding RNA signature to predict recurrence of patients with laryngeal cancer.

Accumulating evidence has shown that aberrant lncRNA expression plays an oncogenic or tumor-suppressive role in the tumorigenesis of laryngeal cancer. However, the prognostic roles of lncRNAs in laryngeal cancer recurrence are still poorly understood. In this study, we obtained lncRNA expression profiles of 109 patients with laryngeal cancer by mining previously published gene expression microarray data from the Gene Expression Omnibus (GEO) and identified two lncRNAs associated with laryngeal cancer recurrence in the training dataset by using Cox regression analysis. Then these two lncRNAs were combined to a two-lncRNA signature for identifying patients at high-risk of disease recurrence. By applying this two-lncRNA signature to the testing dataset, a clear separation was observed in the survival curves between patients with low- or high-risk scores, indicating good reproducibility of this two-lncRNA signature in predicting disease-free survival of laryngeal cancer. Further analysis revealed that the prognostic value of the two-lncRNA signature was independent of other clinical features, including age, stage and grade. Subsequent gene set enrichment analysis suggested that the two-lncRNA signature was more likely to involve with GPCRs downstream signaling pathway, potassium channel pathway and aurora-A pathway. Our study demonstrated that the two-lncRNA signature may be a novel potential biomarker for prognosis of laryngeal cancer and may provide novel insights into the molecular mechanism of laryngeal cancer.

Long noncoding RNA HAS2-AS1 mediates hypoxia-induced invasiveness of oral squamous cell carcinoma.

A hypoxic microenvironment plays important roles in the progression of solid tumors, including oral squamous cell carcinoma (OSCC). Long noncoding RNAs (lncRNAs) have gained much attention in the past few years. However, it is not clear whether lncRNAs can regulate hypoxia adaptation of OSCC or which lncRNAs participate in this process. Using a lncRNA microarray, we analyzed the aberrant lncRNA expression profiles in OSCC tissues compared with paired normal oral mucosa and in hypoxic OSCC cells compared with normoxic OSCC cells. The top 10 lncRNAs that had more than threefold increase with P-value <0.01 in both microarray data were validated by qRT-PCR. Among the top 10 lncRNAs, hyaluronan synthase 2 antisense 1 (HAS2-AS1) was the only one that has a hypoxia-responsive element (HRE) on its promoter region and has been validated to increase in OSCC tissues and in cells cultured under hypoxia. Tumor HAS2-AS1 levels were closely associated with lymph node metastasis and hypoxic tumor status in patients with OSCC. Moreover, the hypoxia-induced HAS2-AS1 expression is dependent on HIF-1α which directly binds to and activates the transcription of HAS2-AS1. In addition, HAS2-AS1 mediates hypoxia-induced epithelial mesenchymal transition of OSCC cells via stabilizing HAS2. In conclusion, our results suggest that hypoxia would induce an overexpression of HAS2-AS1 in an HIF-1α dependent manner. The increase of HAS2-AS1 plays important roles mediating the hypoxia-regulated EMT and invasiveness of OSCC.

Microarray profiling of long non-coding RNAs associated with idiopathic pulmonary arterial hypertension.

Idiopathic pulmonary arterial hypertension (IPAH) is a fatal disease with a poor prognosis and the molecular pathways underlying the pathogenesis of IPAH are not fully understood. In the present study, the long non-coding RNA (lncRNA) and mRNA expression profiles of lymphocytes obtained from 12 IPAH patients and 12 healthy controls were analyzed using Arraystar Human lncRNA Microarray v2.0, and their roles in the pathogenesis of IPAH were characterized using comprehensive bioinformatic tools. A total of 2,511 lncRNAs (2,004 upregulated and 507 downregulated) and 1,169 mRNAs (609 upregulated and 560 downregulated) were aberrantly expressed in IPAH patients with a fold-change of >2.0. Gene ontology analysis indicated that the coexpressed lncRNAs and mRNAs were involved in the process of translation, while pathway analysis indicated that the coexpressed RNAs were enriched during the process of oxidative phosphorylation and in the ribosome. It was concluded that dysregulated lncRNAs are potentially associated with IPAH, and aberrant lncRNA expression in blood cells may serve as a diagnostic marker of IPAH.