Project description:BackgroundCircular RNAs (circRNAs) may function as the decoys for microRNAs (miRNAs) or proteins, the templates for translation, and the sources of pseudogene generation. The purpose of this study is to determine the diagnostic circRNAs, which are related to lung adenocarcinoma (LUAD), that adsorb miRNAs on the basis of the competing endogenous RNA (ceRNA) hypothesis.MethodsThe differentially expressed circRNAs (DEcircRNAs) in LUAD were revealed by the microarray data (GSE101586 and GSE101684) that were obtained from the Gene Expression Omnibus (GEO) database. The miRNAs that were targeted by the DEcircRNAs were predicted with the CircInteractome, and the target mRNAs of the miRNAs were found by the miRDB and the TargetScan. The ceRNA network was built by the Cytoscape. The potential biological roles and the regulatory mechanisms of the circRNAs were investigated by the Gene Ontology (GO) enrichment analysis and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. The expression of the host genes of circRNAs was examined by the Ualcan. The survival analysis was performed by the Kaplan-Meier plotter.ResultsIn comparison with normal lung tissues, LUAD tissues contained 7 overlapping cancer-specific DEcircRNAs with 294 miRNA response elements (MREs). Among the 7 DEcircRNAs, 3 circRNAs (hsa_circ_0072088, hsa_circ_0003528, and hsa_circ_0008274) were upregulated and 4 circRNAs (hsa_circ_0003162, hsa_circ_0029426, hsa_circ_0049271, and hsa_circ_0043256) were downregulated. A circRNA-miRNA-mRNA regulatory network, which included 33 differentially expressed miRNAs (DEmiRNAs) and 2007 differentially expressed mRNAs (DEmRNAs), was constructed. These mRNAs were enriched in the biological function of cell-cell adhesion, response to hypoxia, and stem cell differentiation and were involved in the PI3K-Akt signaling, HIF-1 signaling, and cAMP signaling pathways.ConclusionOur results indicated that 7 DEcircRNAs could have diagnostic value for LUAD. Additionally, the circRNAs-mediated ceRNA network might provide a novel perspective into unraveling the pathogenesis and progression of LUAD.

Project description:Background: Lung adenocarcinoma (LUAD) is the leading cause of deaths worldwide, and metastasis accounts for the vast majority of cancer-related deaths. Driver mutations play important roles in treatment decision making for LUAD patients, while the complicated metastatic progress cannot be explained by genetic aberrations alone. Epigenomic reprogramming is particularly notable as an important signature of the metastasis transition. However, long noncoding RNAs (lncRNAs) hijacked by super-enhancer (SE), vital regulatory elements in epigenome, remain elusive in the progression of metastasis. Methods: SE associated lncRNAs microarray was utilized to identified the dysregulated lncRNAs related to metastasis. ChIP-seq, Hi-C data analysis and luciferase reporter assay were utilized to confirm LINC01977 was hijacked by SE. In vitro and in vivo assays were applied to elucidate effects of LINC01977 on the malignancy of LUAD. Results: In this study, we identified that LINC01977, a cancer-testis lncRNA, was up-regulated in tumor, which was driven by a …kb-long SE upstream of LINC01977 and sensitive to BRD4 inhibitor. LINC01977-antisense oligonucleotides (ASO) dramatically suppresses proliferation and invasion both in vitro and in vivo. Mechanically, LINC01977 promotes phosphorylation of SMAD3 to facilitate its nuclear retention, and it also act as a scaffold to cooperate the interaction between SMAD3 and CBP/P300, the transcriptional co-activators, to regulate the downstream target gene ZEB1. Interestingly, SMAD3 also positively regulated LINC09177 transcription by binding the promoter and active elements of its SE, which was medicated by canonical TGF-β signaling secreted by M2-like tumor-associated macrophages (TAM2). We also revealed that the expression of LINC01977 was positively correlated with TAM2 infiltration especially in early stage. Additionally, stage I LUAD patients with high LIN01977 expression predicated a shorter progression-free survival (PFS). Conclusions: LINC01977 promotes the malignant progression of LUAD through facilitating the interaction between SMAD3 and CBP/P300. The upregulation of LINC01977 was medicated by super-enhancer and TAM2 infiltration, dependent on canonical TGF-β signaling. LINC01977 could be a valuable therapeutic target especially for early stage patients.

Project description:Retinoblastoma (RB), the most common intraocular malignancy, typically occurs in pediatric patients under the age of 6 years. The present study aimed to explore the long noncoding RNA (lncRNA) expression profile in RB and identify novel lncRNA biomarkers to facilitate the investigation of molecular mechanisms of RB and improve clinical therapy. Raw microarray data for the comparison of gene expression between three RB and three adjacent normal tissue samples were downloaded from Gene Expression Omnibus (dataset no. GSE111168). After identification of differentially expressed lncRNAs (DELs) and differentially expressed mRNAs (DEMs) in RB, functional enrichment analyses and a DEL-DEM weighted correlation network analysis were performed. A total of 3,915 DELs (1,774 upregulated and 2,141 downregulated) and 3,715 DEMs (1,492 upregulated and 2,223 downregulated) were identified in RB. The DEL-targeted DEMs were highly enriched by genes involved in hexose transport, muscle tissue morphogenesis, the stereocilium membrane, endothelin B receptor binding and γ-filamin/ABP-L, α-actinin and telethonin binding protein of the Z-disc binding. Furthermore, associations of the DELs and DEMs with several pathways were determined, including PI3K/AKT, Hippo and cancer signaling, as well as extracellular matrix-receptor interaction pathways. Coexpression network analysis revealed that the top three DELs, lnc-DAZ1-161, lnc-HDAC7-21 and lnc-OR52A1-55, formed coexpression modules with 181, 156 and 210 DEMs, respectively. In addition, the top three DEMs, namely EIF1AY, GSTM1 and NLRP11, formed coexpression modules with 33, 50 and 41 DELs, respectively. Validation using reverse transcription-quantitative PCR indicated that the expression of representative lncRNAs (lnc-DAZ1-161 and lnc-HDAC7-21) in RB cells in vitro was consistent with that in RB tissues in the database, while the expression of lnc-OR52A1-55 was not consistent with the database. These results suggested that the aberrant lncRNA expression profile in RB is related to the differential regulation of numerous physiological and pathological processes. The lncRNA and mRNA profiles in RB identified may provide novel targets for the investigation of its molecular mechanisms and thus lead to improvements in clinical therapy for RB.

Project description:Pancreatic ductal adenocarcinoma (PDAC) is known by its aggressiveness and lack of effective therapeutic options. Thus, improvement in current knowledge of molecular changes associated with pancreatic cancer is urgently needed to explore novel venues of diagnostics and treatment of this dismal disease. While there is mounting evidence that long noncoding RNAs (ncRNAs) transcribed from intronic and intergenic regions of the human genome may play different roles in the regulation of gene expression in normal and cancer cells, their expression pattern and biological relevance in pancreatic cancer is currently unknown. In the present work we investigated the relative abundance of a collection of ncRNAs in patients’ pancreatic tissue samples aiming at identifying gene expression profiles correlated to pancreatic cancer and metastasis. To investigate the relative abundance, we used a custom 3,355-element spotted cDNA microarray interrogating protein-coding genes and putative ncRNA were used to obtain expression profiles from 38 clinical samples of tumor and non-tumor pancreatic tissues. Bioinformatics analyses were performed to characterize structure and conservation of ncRNAs expressed in pancreatic tissues, as well as to identify expression signatures correlated to tissue histology. Strand-specific reverse transcription followed by PCR and qRT-PCR were employed to determine strandedness of ncRNAs and to validate microarray results, respectively. We found that long intronic/intergenic ncRNAs are ubiquitously expressed across tumor and non-tumor pancreatic tissue samples. Enrichment of promoter-H3K4me3 associated chromatin marks and over-representation of conserved DNA elements and stable secondary structure predictions suggest that these transcripts are generated from independent transcriptional units and that at least a fraction is under evolutionary selection, and thus potentially functional. Statistically significant expression signatures comprising protein-coding mRNAs and long ncRNAs that correlate to PDAC or to pancreatic cancer metastasis were identified. Interestingly, loci harboring intronic ncRNAs differentially expressed in PDAC metastases were enriched in genes associated to the MAPK pathway. Orientation-specific RT-PCR documented that intronic transcripts are expressed in sense, antisense or both orientations relative to protein-coding mRNAs. Differential expression of a subset of intronic ncRNAs (PPP3CB, MAP3K14 and DAPK1 loci) in metastatic samples was confirmed by Real-Time PCR. All this results reveal sets of long intronic ncRNAs expressed in pancreatic tissues whose abundance is correlated to PDAC or metastasis, thus pointing to the potential relevance of this class of transcripts in biological processes related to malignant transformation and metastasis in pancreatic cancer. Fluorescent labeled cDNA targets derived from pancreatic tumor and non-tumor tissue from each patient were combined and hybridized to spotted cDNA microarrays. For each patient, a replicate hybridization was performed. For each sample, there are 4 replicate measurements for each probe.

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Identification of differentially expressed RNAs of lung cancer cells.

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