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Oncogene‐like effects of TMEM92‐AS1: LncRNA TMEM92‐AS1 regulates the expression of downstream target gene CCL5 by binding with YBX1 protein to play the role of oncogene and affects prognosis of patients with gastric cancer. TMEM92‐AS1 may also promote the secretion of G‐CSF by tumour cells to increase the level of neutrophils in the peripheral blood., Numerous studies have revealed that long noncoding RNAs (lncRNAs) with oncogene properties play vital roles in gastric cancer (GC). In this study, we aimed to elucidate the function of TMEM92‐AS1 in GC progression and to investigate its underlying mechanisms. TMEM92‐AS1 was filtered from the Gene Expression Omnibus database. GC tissues and adjacent normal tissues were used to detect the expression level of TMEM92‐AS1. MTT, colony‐formation assays, Edu, cell cycle, apoptosis and subcutaneous tumour formation assays were used to detect the role of TMEM92‐AS1 in cell function. RNA transcriptome sequencing was used to seek downstream target genes. Reverse transcription (RT)‐qPCR, western blot, RNA and chromatin immunoprecipitation assays were used to investigate the mechanisms involved. TMEM92‐AS1 was significantly overexpressed in GC tissues and correlated with poor overall survival and disease‐free survival. Furthermore, TMEM92‐AS1 promoted GC cell proliferation and migration in vitro and tumorigenic ability in vivo. RNA transcriptome sequence analysis revealed a potential downstream target gene, C‐C motif chemokine ligand 5 (CCL5), and a mechanistic study found that TMEM92‐AS1 regulated CCL5 by binding to the transcription factor Y‐box binding protein 1(YBX1), which has oncogene properties. In addition, TMEM92‐AS1 was found to be associated with peripheral blood leukocyte counts, especially neutrophils. Further investigation found that TMEM92‐AS1 may affect leukocytes via regulation of the expression of granulocyte colony‐stimulating factor in GC tissues. Our data provide an in‐depth insight into the mechanism behind the lncRNA TMEM92‐AS1, how it promotes GC progression and the possible mechanism in affecting peripheral leukocyte counts. Therefore, TMEM92‐AS1 is a potential target for GC individualized therapy and prognostic assessment.

MicroRNAs are crucial regulators in the phenotype switch of vascular smooth muscle cells (VSMCs). Nonetheless, the role of miR-146b-3p in VSMCs remains unclear. In the present study, platelet-derived growth factor-BB (PDGF-BB) at different concentrations was employed to stimulate VSMCs for different times, to establish the model of VSMC dysfunction. The relative expression of miR-146b-3p was quantified by quantitative real-time polymerase chain reaction (qRT-PCR). The proliferation of VSMCs was measured by BrdU assay. Flow cytometry analysis was employed for the analysis of cell cycle. VSMC migration was detected by Transwell assay. Phosphoinositide-3 kinase catalytic subunit-gamma (PIK3CG) and markers of VSMC differentiation, including α-SMA, SM-22α, SMMHC, and Calponin were examined employing Western blot. The targeting relationship between miR-146b-3p and PIK3CG 3ʹ-UTR was affirmed by dual-luciferase gene assay. We report that the reduction of miR-146b-3p expression was induced by PDGF-BB in a time-dependent and dose-dependent manner (P, Graphical Abstract

Dysregulated expression of long non-coding RNAs (lncRNAs) has been reported in many types of cancers, indicating that it has important regulatory roles in human cancer biology. Recently, lncRNA urothelial cancer-associated 1 (UCA1) was shown to be dysregulated in many cancer types, but the detailed mechanisms remain largely unknown. In our study, we found that upregulated UCA1 is associated with poor prognosis in gastric cancer patients. Further experiments revealed that UCA1 knockdown significantly repressed the proliferation and migration both in vitro and in vivo. Moreover, RNA sequencing (RNA-seq) analysis revealed that UCA1 knockdown preferentially affected genes that are linked to cell proliferation, cell cycle, and cell migration. Mechanistically, UCA1 promotes cell proliferation progression through repressing p21 and Sprouty RTK signaling antagonist 1 (SPRY1) expression by binding to EZH2. We found that UCA1 could mediate the trimethylation of H3K27 in promoters of p21 and SPRY1. To our knowledge, this is the first report showing the global gene profile of downstream targets of UCA1 in the progression of gastric cancer. Collectively, our data reveal the important roles of UCA1 in gastric cancer (GC) oncogenesis. Keywords: UCA1, cell proliferation, cell migration, p21, SPRY1

Cholangiocarcinoma (CCA) is the most common biliary tract malignancy, with a low survival rate and limited treatment options. Long non-coding RNAs (lncRNAs) have recently been verified to have significant regulatory functions in many kinds of human cancers. It was discovered in this study that the lncRNA PVT1, whose expression is significantly elevated in CCA, could be a molecular marker of CCA. Experiments indicated that PVT1 knockdown greatly inhibited cell migration and proliferation in vitro and in vivo. According to RNA sequencing (RNA-seq) analysis, PVT1 knockdown dramatically influenced target genes associated with cell angiogenesis, cell proliferation, and the apoptotic process. RNA immunoprecipitation (RIP) analysis demonstrated that, by binding to epigenetic modification complexes (PRC2), PVT1 could adjust the histone methylation of the promoter of ANGPTL4 (angiopoietin-like 4) and, thus, promote cell growth, migration, and apoptosis progression. The data verified the significant functions of PVT1 in CCA oncogenesis, and they suggested that PVT1 could be a target for CCA intervention. Keywords: cholangiocarcinoma, lncRNA PVT1, ANGPTL4

Background Recently, increasing evidence shows that long noncoding RNAs (lncRNAs) play a significant role in human tumorigenesis. However, the function of lncRNAs in human gastric cancer remains largely unknown. Results By using publicly available expression profiling data from gastric cancer and integrating bioinformatics analyses, we screen and identify a novel lncRNA, HOXC-AS3. HOXC-AS3 is significantly increased in gastric cancer tissues and is correlated with clinical outcomes of gastric cancer. In addition, HOXC-AS3 regulates cell proliferation and migration both in vitro and in vivo. RNA-seq analysis reveals that HOXC-AS3 knockdown preferentially affects genes that are linked to proliferation and migration. Mechanistically, we find that HOXC-AS3 is obviously activated by gain of H3K4me3 and H3K27ac, both in cells and in tissues. RNA pull-down mass spectrometry analysis identifies that YBX1 interacts with HOXC-AS3, and RNA-seq analysis finds a marked overlap in genes differentially expressed after YBX1 knockdown and those transcriptionally regulated by HOXC-AS3, suggesting that YBX1 participates in HOXC-AS3-mediated gene transcriptional regulation in the tumorigenesis of gastric cancer. Conclusions Together, our data demonstrate that abnormal histone modification-activated HOXC-AS3 may play important roles in gastric cancer oncogenesis and may serve as a target for gastric cancer diagnosis and therapy. Electronic supplementary material The online version of this article (10.1186/s13059-018-1523-0) contains supplementary material, which is available to authorized users.

Growth differentiation factor 15 (GDF15), a member of the TGF-β superfamily of cytokines, has been reported to exert very heterogeneous functions in various tumors. However, its expression and roles in mediating non-small-cell lung cancer (NSCLC) progression remain unknown. In this study, we found that GDF15 is downregulated in paired NSCLC tissues and correlated with poor clinical outcomes in NSCLC. A functional experiment demonstrated that overexpression of GDF15 significantly repressed NSCLC proliferation both in vitro and in vivo. Mechanistic studies reveal that inhibition of EZH2 expression prevented its binding to the GDF15 promoter region and reduced the trimethylation modification pattern of H3K27. Together, our data uncover that GDF15 is a direct target of EZH2 and, as a regulator of proliferation, might serve as a candidate prognostic biomarker and target for new therapies in human NSCLC. Keywords: EZH2, epigenetic, GDF15, cell proliferation, NSCLC

Preeclampsia (PE) is a syndrome manifested by high blood pressure that could develop in the latter half of pregnancy; however, the underlying mechanisms are not understood. Recent evidence points to the function of noncoding RNAs (ncRNAs) as novel regulators of the invasion, migration, proliferation, and apoptosis of trophoblasts involved in the development of placental vasculature. Here, we investigated the role of long intergenic ncRNA 00473 (linc00473) in PE and the associated molecular mechanisms. The expression of linc00473 was downregulated in the placenta of patients with severe PE as revealed by qRT-PCR analysis. In vitro, linc00473 knockdown in trophoblast cell lines HTR-8/SVneo, JAR, and JEG3 significantly inhibited cell proliferation and promoted apoptosis, whereas linc00473 overexpression stimulated trophoblast proliferation. The mechanistic insights were provided by RNA-seq and qRT-PCR, which revealed that linc00473 could regulate the transcription of genes relevant to cell growth, migration, and apoptosis. In particular, linc00473 inhibited the expression of tissue factor pathway inhibitor 2 (TFPI2) through binding to lysine-specific demethylase 1 (LSD1). These results indicate that linc00473 could be involved in the pathogenesis and development of PE and may be a candidate biomarker as well as therapeutic target for this disease. Keywords: preeclampsia, linc00473, LSD1, proliferation

Substantial evidence shows that long non-coding RNAs (lncRNAs) participate in many biological mechanisms, and their dysregulation are also involved in the development and progression of cancers, including gastric cancer (GC). Long intergenic non-coding RNA 00324 (LINC00324), a 2115 bp ncRNA, is located on chromosome 17p13.1. The biological function and molecular mechanisms of LINC00324 in GC remains undiscovered. In this paper, we found that the expression level of LINC00324 was significantly upregulated in GC tissues compared with the corresponding normal tissues. The overexpression of LINC00324 was correlated with advanced TNM stage, larger tumor size, and lymph node metastasis as well as poor prognosis. Further experiments revealed that knockdown of LINC00324 could suppress the proliferation of GC cells. RNA transcriptome sequencing technology revealed that FAM83B may be a significant downstream target gene of LINC00324. LINC00324 could combine with the RNA-binding protein (RBP) human antigen R (HuR) and thus stabilize the expression of FAM83B. Moreover, rescue assays showed that the reduced FAM83B expression partially reversed the promotion of cell growth in GC induced by the overexpression of LINC00324. In conclusion, our study revealed that LINC00324 acted as an oncogene in tumorigenesis and progression, suggesting that it could be a new biomarker in diagnosis and prognosis of GC.

Background Mounting evidence indicates that long noncoding RNAs (lncRNAs) could play a pivotal role in cancer biology. However, the role and molecular mechanism and global genes that were mediated by lncRNA AFAP1-AS1 in non–small cell lung cancer (NSCLC) remain largely unknown. Methods Expression of AFAP1-AS1 was analyzed in 92 NSCLC tissues and cell lines by Quantitative real time polymerase chain reaction (qRT-PCR). The effect of AFAP1-AS1 on proliferation was evaluated by function assays both in in vitro and in vivo. RNA-seq assays were performed after knockdown AFAP1-AS1. RNA immunoprecipitation (RIP) was performed to confirm the interaction between AFAP1-AS1 and EZH2. Chromatin immunoprecipitation (ChIP) was used to study the promoter region of p21. Results AFAP1-AS1 expression was increased in NSCLC tissues and was correlated with clinical outcomes of NSCLC. Further experiments revealed that inhibition of its expression in NSCLC cells resulted in diminished cell growth in vitro and in vivo. RNA-seq revealed that knockdown of AFAP1-AS1 could induce the expression of p21. Mechanistic investigations found that AFAP1-AS1 could interact with EZH2 and recruit EZH2 to the promoter regions of p21, thus epigenetically repressing p21 expression. Conclusions Together, these results suggest that lncRNA AFAP1-AS1 may serve as a candidate prognostic biomarker and target for new therapies in human NSCLC. Electronic supplementary material The online version of this article (10.1186/s12943-018-0836-7) contains supplementary material, which is available to authorized users.

Background/Aims: Lung cancer (LC) is a serious disease with high morbidity and mortality. Long noncoding RNAs (lncRNAs) have garnered attention because they participate in diverse human disorders, including cancer. Our study examined the long intergenic noncoding RNA 00707 (LINC00707). The effects of LINC00707 on lung adenocarcinoma (LAD) and molecular mechanisms are unclear. This study is aimed to investigate the role of LINC00707 in the malignant processes of LAD. Methods: Quantitative reverse transcription PCR (qRT-PCR) was used to examine the expression level of LINC00707 in tissues and cell lines. The association of LINC00707 expression and postoperative prognosis was analyzed by the Kaplan-Meier method and log-rank test. Cell proliferation was evaluated in vitro and in vivo. Transwell assays were performed to examine cell migration. Cell cycle and apoptosis was determined by flow -cytometric and western blot analyses. Microarray analysis was conducted to screen for the downstream target gene Cdc42 of LINC00707, which was identified by qRT-PCR, functional analysis, and rescue experiment. Results: The expression level of LINC00707 was clearly upregulated in LAD tissues compared to that in corresponding normal tissues. Its overexpression was related to advanced TNM stage, larger tumor size, lymphatic metastasis, and poor prognosis. Functional assays revealed that LINC00707 knockdown repressed LAD cell proliferation both in vitro and in vivo. This process may involve the inducing of G1 arrest and apoptosis. Moreover, cell migration was impaired after LINC00707 inhibition. Microarray analysis and rescue assays suggested that Cdc42 is an important target gene involved in the carcinogenesis of LINC00707. Conclusions: In summary, LINC00707 is a noncoding oncogene that exerts important regulatory functions in LAD, suggesting its potential as a biomarker in the prognosis and treatment of LAD.

Background: In recent years, long non-coding RNAs (lncRNAs) have been shown to be a novel class of regulators of cancer biological processes. Although lncRNAs are dysregulated in numerous cancer types, limited data are available on the expression profiles and potential functions of lncRNAs in lung adenocarcinoma (LUAD). This study evaluated the expression and biological roles of lncRNA SOX21 antisense RNA 1 (SOX21-AS1) in LUAD. Methods: Quantitative reverse transcription PCR (qRT-PCR) was performed to detect the expression levels of SOX21-AS1 in 68 pairs of LUAD tissues and corresponding non-tumor tissues. The effect of SOX21-AS1 on proliferation was evaluated by MTT, colony formation, EdU assays, flow-cytometric analysis and in vivo tumor formation assays. Real-time PCR, western-blot and immunohistochemistry were used to evaluate the mRNA and protein expression of p57. Results: Higher expression levels of SOX21-AS1 positively correlated with tumor size and advanced tumor–node–metastasis (TNM) stage. Multivariate analyses indicated that SOX21-AS1 expression could serve as an independent prognostic factor for overall survival of LUAD. Furthermore, knockdown of SOX21-AS1 significantly inhibited LUAD cell proliferation both in vitro and in vivo and induced cell cycle phase arrest and cell apoptosis. Importantly, through qRT-PCR and western blot analysis, we found that inhibition of SOX21-AS1 remarkably induced p57 expression. Conclusions: Collectively, our study demonstrates that SOX21-AS1 is involved in the development and progression of LUAD and that SOX21-AS1 may be a potential diagnostic factor as well as a target for new therapies for patients with LUAD.

Gastric cancer (GC) is the third leading cause of cancer death due to its poor prognosis and limited treatment options. Evidence indicates that pseudogene-derived long noncoding RNAs (lncRNAs) may be important players in human cancer progression, including GC. In this paper, we report that a newly discovered pseudogene-derived lncRNA named DUXAP8, a 2107-bp RNA, was remarkably upregulated in GC. Additionally, a higher level of DUXAP8 expression in GC was significantly associated with greater tumor size, advanced clinical stage, and lymphatic metastasis. Patients with a higher level of DUXAP8 expression had a relatively poor prognosis. Further experiments revealed that knockdown of DUXAP8 significantly inhibited cell proliferation and migration, as documented in the SGC7901 and BGC823 cell lines. Furthermore, RNA immunoprecipitation and chromatin immunoprecipitation assays demonstrated that DUXAP8 could epigenetically suppress the expression of PLEKHO1 by binding to EZH2 and SUZ12 (two key components of PRC2), thus promoting GC development. Taken together, our findings suggest that the pseudogene-derived lncRNA DUXAP8 promotes the progression of GC and is a potential therapeutic target for GC intervention.

Recently, long noncoding RNAs (lncRNAs) have been shown to have important regulatory roles in human cancer biology. The aim of this study was to evaluate the expression and biological role of lncRNA CASC2 in non-small cell lung cancer (NSCLC). By bioinformatics analysis, we found that CASC2 was significantly decreased in NSCLC. qRT-PCR was performed to investigate the expression of CASC2 in tumor tissues and corresponding non-tumor NSCLC tissues from 76 patients. The lower expression of CASC2 was remarkably correlated with advanced TNM stage and tumor size. Multivariate analyses found that CASC2 expression served as an independent predictor for overall survival of NSCLC. Moreover, overexpression of CASC2 significantly inhibited NSCLC cell proliferation both in vitro and in vivo. In conclusion, our study demonstrated that CASC2 is involved in the development and progression of NSCLC and shows that CASC2 may be a potential diagnostic and target for new therapies in patients with NSCLC.

// Erbao Zhang 1,* , Dandan Yin 2,* , Liang Han 3,* , Xuezhi He 1 , Xinxin Si 1 , Wenming Chen 4 , Rui Xia 1 , Tongpeng Xu 4 , Dongying Gu 5 , Wei De 1 , Renhua Guo 4 , Zhi Xu 5 and Jinfei Chen 5,6 1 Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, Jiangsu, PR China 2 Central Laboratory, the Second Affiliated Hospital of Southeast University, Nanjing, Jiangsu, PR China 3 Department of Oncology, Xuzhou Central Hospital, Affiliated Xuzhou Hospital, College of Medicine, Southeast University, Xuzhou, Jiangsu, PR China 4 Department of Oncology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, PR China 5 Department of Oncology, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, PR China 6 Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, Jiangsu, PR China 7 Departments of Pathology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, PR China * These authors have contributed equally to this work and should be regarded as joint first authors Correspondence to: Jinfei Chen, email: // Zhi Xu, email: // Renhua Guo, email: // Wei De, email: // Keywords : E2F1, LINC00668, cell cycle, proliferation, gastric cancer Received : March 10, 2015 Accepted : December 12, 2015 Published : December 23, 2015 Abstract Recently, long noncoding RNAs (lncRNAs) have been shown to have important regulatory roles in human cancer biology. By utilizing publicly available lncRNAs expression profiling data and integrating analyses, we screened out LINC00668, whose expression is significantly increased and correlated with outcomes in gastric cancer (GC). Further experiments revealed that LINC00668 knockdown significantly repressed proliferation, both in vitro and in vivo . Mechanistic investigations showed that LINC00668 was a direct transcriptional target of E2F transcription factor 1 (E2F1). We further demonstrated that LINC00668 was associated with PRC2 and that this association was required for epigenetic repression of cyclin-dependent protein kinase inhibitors (CKIs), including p15, p16, p21, p27 and p57, thus contributing to the regulation of the gastric cancer cell cycle. Our results suggest that E2F1-activated LINC00668, as a cell cycle regulator, enriches the mechanistic link between lncRNA and the E2F1-mediated cell cycle regulation pathway and may serve as a candidate prognostic biomarker and target for new therapies in human gastric cancer.

Evidence indicates that long non-coding RNAs (lncRNAs) play a critical role in the regulation of tumor cellular processes, such as proliferation, apoptosis, and metastasis. LncRNA CRNDE (Colorectal Neoplasia Differentially Expressed) is located at human chromosome 16 and has been found overexpressed in a variety of cancers including colorectal cancer (CRC). In this paper, we report that lncRNA CRNDE expression was remarkably upregulated in CRC tissues and that lncRNA CRNDE overexpression was positively correlated with advanced pathological stages and larger tumor sizes. In addition, the knockdown of CRNDE significantly suppressed proliferation and caused apoptosis of CRC cells both in vitro and in vivo. Furthermore, RNA immunoprecipitation and chromatin immunoprecipitation assays demonstrated that lncRNA CRNDE could epigenetically suppress the expressions of dual-specificity phosphatase 5 (DUSP5) and CDKN1A by binding to EZH2 (the key components of Polycomb repressive complex 2 (PRC2)), thus promoting CRC development. In conclusion, our data suggest that the lncRNA CRNDE promotes the progression of CRC and is a potential therapeutic target for CRC intervention.

Recently, a novel class of transcripts, long noncoding RNAs (lncRNAs), is being identified at a rapid pace. These RNAs have critical roles in diverse biological processes, including tumorigenesis. One of them, BLACAT1, a cancer-associated long noncoding RNA, exerts regulatory functions in various biological processes in cancer cells, however, the role of BLACAT1 in colon cancer remains unclear. Our experiments showed that increased BLACAT1 was an independent unfavorable prognostic indicator for colorectal cancer, and revealed that BLACAT1 knockdown significantly repressed proliferation, both in vitro and in vivo. Mechanistic investigations demonstrated that BLACAT1 had a key role in G1/G0 arrest, and showed that BLACAT1 can repress p15 expression by binding to EZH2, thus contributing to the regulation of CRC cell cycle and proliferation. Our results suggest that BLACAT1, as a cell cycle regulator, may serve as a potential target for colon cancer prevention and treatment in human CRC.

Recent evidence highlights long noncoding RNAs (lncRNAs) as crucial regulators of cancer biology that contribute to tumorigenesis. LncRNA TUG1 was initially detected in a genomic screen for genes upregulated in response to taurine treatment in developing mouse retinal cells. Our previous study showed that TUG1 could affect cell proliferation through epigenetically regulating HOXB7 in human non-small cell lung cancer. However, the clinical significance and potential role of TUG1 in GC remains unclear. In this study, we found that TUG1 is significantly increased and is correlated with outcomes in gastric cancer (GC). Further experiments revealed that knockdown of TUG1 repressed GC proliferation both in vitro and in vivo. Mechanistic investigations showed that TUG1 has a key role in G0/G1 arrest. We further demonstrated that TUG1 was associated with PRC2 and that this association was required for epigenetic repression of cyclin-dependent protein kinase inhibitors, including p15, p16, p21, p27 and p57, thus contributing to the regulation of GC cell cycle and proliferation. Together, our results suggest that TUG1, as a regulator of proliferation, may serve as a candidate prognostic biomarker and target for new therapies in human GC.