Expression and function of miRNAs in gastric carcinoma
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus Rattus norvegicus Homo sapiens
PROVIDER: GSE18880 | GEO | 2010/02/10
SECONDARY ACCESSION(S): PRJNA121141
REPOSITORIES: GEO
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2016-05-24 | MSV000079767 | MassIVE
Project description:To identify tumor suppressive microRNAs repressed by DNA hypermethylation in gastric cancer (GC), we analyzed methylome and miRNome of EpCAM+/CD44+ GC cells. Among a set of microRNAs hypermethylated and downregulated in GC, mir-1271 was uncovered as a microRNA repressed by DNA hypermethylation in GC. Forced expression of mir-1271 significantly suppressed growth, migration, and invasion of GC cells both in vitro and in vivo. To identify target genes and cancer signaling pathways regulated by mir-1271, we examined differentially-expressed genes responsive to mir-1271 by performing RNA-sequencing.
2018-06-12 | GSE87785 | GEO
Project description:We investigated the involvement of microRNAs (miRNAs) in gastric cancers. MiRNA expression was profiled from 40 cancerous and 40 non-cancerous tissues obtained from the National Cancer Centre, Singapore, and Singhealth Tissue Repository, Singapore. We identified 80 differentially expressed miRNAs in tumors compared with normal tissues. Among these miRNAs, we identified hsa-mir-486-5p (mir-486) as a significantly downregulated miRNA in GC. Subsequent functional characterization revealed that mir-486 playing a tumor suppressor role. We also observed frequent genomic deletion of mir-486 in 20-30% of GCs. To our knowledge, mir-486 represents one of the first tumor suppressor miRNAs in GC inactivated through genomic deletion. MiRNA expression was profiled on Agilent Human miRNA Microarrays (V2) representing 723 human and 76 human viral miRNAs in 40 normal and 40 cancerous gastric tissues.
2011-08-01 | E-GEOD-23739 | biostudies-arrayexpress
Project description:We determined the effect of p53 activation on de novo protein synthesis using quantitative proteomics of newly synthesized proteins (pulsed stable isotope labeling with amino acids in cell culture, pSILAC) in combination with mRNA and non-coding RNA expression analyses by next generation sequencing (RNA-, miR-Seq) in the colorectal cancer (CRC) cell line SW480. Furthermore, genome-wide DNA binding of p53 was analyzed by chromatin-immunoprecipitation (ChIP-Seq). Thereby, we identified differentially regulated mRNAs (1258 up, 415 down), miRNAs (111 up, 95 down), lncRNAs (270 up, 123 down) and proteins (542 up, 569 down). Changes in mRNA and protein expression levels showed a positive correlation (r = 0.50, p < 0.0001). More transcriptionally induced genes displayed occupied p53 binding sites (4.3% mRNAs, 7.2% miRNAs, 6.3% lncRNAs, 5.9% proteins) than repressed genes (2.4% mRNAs, 3.2% miRNAs, 0.8% lncRNAs, 1.9% proteins), suggesting indirect mechanisms of repression. Around 50% of the downregulated proteins displayed seed-matching sequences of p53-induced miRNAs in the corresponding 3’-UTRs. Moreover, proteins repressed by p53 significantly overlapped with those previously shown to be repressed by miR-34a. We confirmed upregulation of the novel direct p53 target genes LINC01021, MDFI, ST14 and miR-486 and showed that ectopic LINC01021 expression inhibited proliferation in SW480 cells. Furthermore, HMGB1, KLF12 and CIT mRNAs were confirmed as direct targets of the p53-induced miR-34a, miR-205 and miR-486-5p, respectively. In line with the loss of p53 function during tumor progression, elevated expression of HMGB1, KLF12 and CIT was detected in advanced stages of cancer. This study provides new insights and a comprehensive catalogue of p53-mediated regulations and p53 DNA binding in CRC cells.
2015-07-23 | PXD001976 | Pride
Project description:We investigated the involvement of microRNAs (miRNAs) in gastric cancers. MiRNA expression was profiled from 40 cancerous and 40 non-cancerous tissues obtained from the National Cancer Centre, Singapore, and Singhealth Tissue Repository, Singapore. We identified 80 differentially expressed miRNAs in tumors compared with normal tissues. Among these miRNAs, we identified hsa-mir-486-5p (mir-486) as a significantly downregulated miRNA in GC. Subsequent functional characterization revealed that mir-486 playing a tumor suppressor role. We also observed frequent genomic deletion of mir-486 in 20-30% of GCs. To our knowledge, mir-486 represents one of the first tumor suppressor miRNAs in GC inactivated through genomic deletion.
2011-08-01 | GSE23739 | GEO
Project description:Revealing Dominant Regulatory MicroRNA-495-3p that Governs Multiple Epigenetic Modifiers in Gastric Carcinogenesis In this study, we identified miR-495-3p targeting multiple epigenetic modifiers through comprehensive miRNA and mRNA profiling analysis with in silico target prediction in GC. Western blotting assay or quantitative real time PCR was performed to confirm the expression of miR-495-3p and targets of it. We applied miRNA mimics to ectopic overexpression in gastric cancer cells and observed tumor suppressive effects of miR-495-3p in the growth and metastasis of cancer. Also, we confirmed the status of CpG islands of miR-495-3p promoter using methylation specific PCR analysis.
2015-09-18 | E-GEOD-67354 | biostudies-arrayexpress
Project description:Circulating microRNAs (miRNAs) in serum may serve as promising diagnostic biomarkers for patients with gastric cancer (GC). Using quantitative reverse transcription polymerase chain reaction (qRT-PCR) based Exiqon panel, we identified 58 differentially expressed miRNAs from 3 GC pool samples and 1 normal control (NC) pool in the initial screening phase. Identified miRNAs were further validated in the training (49 GC VS. 47 NCs) and validation phases (154 GC VS. 120 NCs) using qRT-PCR. Consequently, six serum miRNAs (miR-10b-5p, miR-132-3p, miR-185-5p, miR-195-5p, miR-20a-3p and miR-296-5p) were significantly overexpressed in GC compared with NCs. The areas under the receiver operating characteristic (ROC) curve of the six-miRNA panel were 0.764 and 0.702 for the training and validation phases, respectively. In conclusion, we identified a six-miRNA panel in serum for the detection of GC.
2016-08-31 | GSE86226 | GEO
Project description:Background & Aims: E-cadherin expression disruption is commonly observed in epithelial cancers and metastasis. Such event is also recognized as a crucial step in gastric cancer (GC) initiation and progression. As aberrant expression of microRNAs often perturb the normal expression and function of pivotal cancer-related genes, we characterized and dissected a pathway initiated by loss of microRNA-101 that causes E-cadherin dysfunction through upregulation of EZH2 expression in GC. Methods: Microarrays were used to profile the expression of microRNAs in human GC. Array-CGH revealed DNA copy number changes that were validated by genomic quantitative PCR and Snapshot. Expression levels of microRNAs, mRNA and protein were determined by quantitative-real time PCR and western-blot/co-immunofluorescence. CDH1 inactivating mechanisms were analyzed. Gain and loss of function experiments were done in KatoIII cells. E-cadherin functionality was assessed by immunofluorescence and flow cytometry. Results: MiR-101 expression was significantly decreased in tumors in comparison with normal gastric mucosas (P<.0001). In 65% of the analyzed GC cases, miR-101 downregulation was caused by deletions and/or microdeletions at miR-101-2 locus. EZH2 overexpression and consequent loss/aberrant E-cadherin expression was found in concomitance with miR-101 downregulation in 41% of the analyzed GC cases. This occurred preferentially in cases retaining allele(s) untargeted by classical CDH1 inactivating mechanisms. MiR-101 gain of function experiments or direct inhibition of EZH2, led to a strong depletion of endogenous EZH2 protein and consequent rescue of functional E-cadherin at the cell membrane, mimicking results obtained with clinical GC samples. Conclusions: Deletions and/or microdeletions at miR-101-2 locus underlying mature miR-101 downregulation and consequent EZH2 overexpression represented a novel cascade of genetic events leading to E-cadherin disruption, preferentially affecting the intestinal-type of GC. In the present study, 37 primary GCs and a pool of 10 normal gastric mucosas were used to acquire the expression of 703 known human mature miRNAs deposited in the Sanger miRBase Sequence Database, Release 10.0 (http://microrna.sanger.ac.uk), as well as 393 novel human miRNAs discovered through deep sequencing and validated by qRT-PCR and array profiling (NCodeM-bM-^DM-" Human miRNA microarray probe set V3 from Invitrogen). The 10 normal gastric mucosa RNA samples were pooled to obtain the normal gastric reference sample, which was labelled and hybridised four times to check arrays' reproducibility.
2012-07-31 | E-GEOD-33743 | biostudies-arrayexpress
Project description:Peritoneal carcinomatosis with malignant ascites is associated with dismal prognosis in gastric cancer. Malignant ascites is the most relevant body fluid in which to seek diagnostic biomarkers for peritoneal carcinomatosis. We aimed to identify and validate ascites-derived circulating microRNAs (miRNAs) that are differentially expressed between liver cirrhosis-associated benign ascites (LC-ascites) and gastric cancer-associated malignant ascites (GC-ascites). MiRNA expression levels were investigated in three independent cohorts. Overall, 165 ascites samples (73 LC-ascites and 92 GC-ascites) were obtained from the National Biobank of Korea. Initially, microarrays were used to screen the expression levels of 2,006 miRNAs in the discovery cohort (n = 22). Subsequently, quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) analyses were used to validate the expression levels of selected miRNAs in the training (n = 70) and validation (n= 73) cohorts. In addition, the levels of carcinoembryonic antigen (CEA), a commonly used tumor marker, were determined in the ascites samples. Expression levels of miR-574-3p, miR-181b-5p, miR-4481, and miR-181d were significantly lower in the GC-ascites samples than in the LC-ascites samples, and miR-181b-5p showed the best diagnostic performance for GC-ascites (area under the curve [AUC] = 0.798 and 0.846 for the training and validation cohorts, respectively). The diagnostic performance of CEA for GC-ascites was improved if CEA and miR-181b-5p were analyzed together (AUC = 0.981 and 0.946 for the training and validation cohorts, respectively). Overall, we identified ascites-derived circulating miRNAs capable of differentiating non-malignant ascites and GC-ascites, and demonstrated that the combined use of miR-181b-5p and CEA produces the optimal diagnostic yield.
2019-02-12 | GSE126399 | GEO
Project description:Pathological markers that can monitor the progression of gastric cancer (GC) may facilitate the diagnosis and treatment of patients with diffuse GC (DGC). To identify microRNAs (miRNAs) that can differentiate between early and advanced DGC in the gastric mucosa, miRNA expression profiling was performed using the NanoString nCounter method in human DGC tumors. Ectopic expression of miR-199a and miR-199b (miR-199a/b) in SNU601 human GC cells accelerated the growth rate, viability, and motility of cancer cells and increased the tumor volume and weight in a mouse xenograft model. To study their clinicopathological roles in patients with GC, miR-199a/b levels were measured in human GC tumor samples using in situ hybridization. High miR-199a/b expression level was associated with enhanced lymphovascular invasion, advanced T stage, and lymph-node metastasis. Using the 3′-untranslated region (UTR) luciferase assay, Frizzled-6 (FZD6) was confirmed to be a direct target of miR-199a/b in GC cells. siRNA-mediated depletion of FZD6 enhanced the motility of SNU601 cells, and addback of FZD6 restored cancer cell motility stimulated by miR-199a/b. In conclusion, miR-199a/b promotes DGC progression by targeting FZD6, implying that miR-199a/b can be used as prognostic and diagnostic biomarkers for the disease.
2023-10-26 | GSE227288 | GEO