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    Abstract:
    Abstract Barrett's esophagus (BE) is characterized by the native stratified squamous epithelium (N) lining the esophagus being replaced by a columnar epithelium with intestinal differentiation (Barrett's mucosa; BM). BM is considered as the main risk factor for esophageal adenocarcinoma (Barrett's adenocarcinoma; BAc). MicroRNAs (miRNAs) are a class of small noncoding RNAs that control gene expression by targeting messenger RNAs and they are reportedly dysregulated in BM. To test the hypothesis that a specific miRNA expression signature characterizes BM development and progression, we performed miRNA microarray analysis comparing native esophageal mucosa with all the phenotypic lesions seen in the Barrett's carcinogenic process. Specimens were collected from 14 BE patients who had undergone esophagectomy, including: 14 with N, 14 with BM, 7 with low‐grade intraepithelial neoplasia, 5 with high‐grade intra‐epithelial neoplasia and 11 with BAc. Microarray findings were further validated by quantitive real‐time polymerase chain reaction and in situ hybridization analyses using a different series of consecutive cases (162 biopsy samples and 5 esophagectomies) of histologically proven, long‐segment BE. We identified a miRNA signature of Barrett's carcinogenesis consisting of an increased expression of 6 miRNAs and a reduced expression of 7 miRNAs. To further support these results, we investigated target gene expression using the Oncomine database and/or immunohistochemical analysis. We found that target gene expression correlated significantly with miRNA dysregulation. Specific miRNAs are directly involved in BE progression to cancer. miRNA profiling significantly expands current knowledge on the molecular history of Barrett's carcinogenesis, also identifying molecular markers of cancer progression.
    Keywords:
    Barrett's esophagus
    Microarray can parallel quantification of large numbers of genes and promises to provide detailed insight into cellular processes involved in the regulation of gene expression. In plants, microarray for gene expression profiling should provide an important way for understanding of gene functions and signaling networks that operate plants growth and development, respond to biotic and abiotic stresses, important agronomic characters. This review focuses on the application of microarray for gene expression profiling in plants. Moreover, development and application of tobacco microarray is also summarized. This review will provide useful information for better application of plant microarray in studies of gene function and regulation mechanism.
    Microarray databases
    Gene chip analysis
    Citations (4)
    PRV,PPV and JEV detection microarray have been prepared in this test.The microarray has been fabricated by spotting target genes on animated slide with the best concentration 200 mg/L of each target gene firstly,then the slide dried,hydrated,UV cross-linked and washed.Probes were labelled by PCR with CY3-dCTP to evaluate the qualification of the microarray.The best concentration of the probe was 3 000 μg/L,with the sensitivity of the microarray detection system of 3 μg/L.The results showed that PRV,PPV and JEV can be detected simultaneously by the microarray with high sensitivity and specificity.The microarray can be reutilized for at least 10 times and conserved for at least 4 months.
    Spotting
    Gene chip analysis
    Citations (0)
    This study aimed to use gene chips to investigate differential gene expression profiles in the occurrence and development of acute myocardial infarction (AMI). The study included 12 AMI patients and 12 healthy individuals. Total mRNA of peripheral bloodwas extracted and reversed-transcribed to cDNA for microarray analysis. After establishing two pools with three subjects each (3 AMI patients and 3 healthy individuals), the remaining samples were used for RT-qPCR to confirm the microarray data. From the microarray results, seven genes were randomly selected for RT-qPCR. RT-qPCR results were analyzed by the 2-ΔΔCt method. Microarray analysis showed that 228 genes were up- regulated and 271 were down-regulated (p ≤ 0.05, |logFC| > 1). Gene ontology showed that these genes belong to 128 cellular components, 521 biological processes, and 151 molecular functions. KEGG pathway analysis showed that these genes are involved in 107 gene pathways. RT-qPCR results for the seven genes showed expression levels consistent with those obtained by microarray. Thus, microarray data could be used to select the pathogenic genes for AMI. Investigating the abnormal expression of these differentially expressed genes might suggest efficient strategies for the prevention, diagnosis, and treatment of AMI.
    Microarray databases
    KEGG
    Gene chip analysis
    Objective: The stroke prone spontaneously hypertensive rat (SHRSP) is an excellent model of human essential hypertension and exhibits salt sensitivity. The aims of this study were to utilise a combination of microarray profiling, construction of congenic strains and novel statistical methods to identify genes and pathophysiological pathways involved in salt-sensitive hypertension. Design and Methods: Renal microarray gene expression profiling was undertaken in 21 week old SHRSP, WKY and SP.WKYGla2a (2a) congenic strains to identify differentially expressed genes in non-salt (n = 3 males/strain) and salt loaded animals (n = 3 males/strain) using the Affymetrix Rat230–2 Gene Chips. The meta-covariate analysis procedure combines model based clustering and binary classification. It exploits the underlying covariance structure in microarray data by identifying meta-covariates that are lower dimensional representations of probe clusters. These clusters are based on similar patterns of gene expression and the ability of the gene cluster to predict the response (e.g., disease vs control). Therefore clusters were obtained of co-varying, response-relevant genes which aided in the biological interpretation of the gene expression data. qRT-PCR was used to validate the microarray data and clusters explored using Ingenuity Pathway Analysis (IPA) software. Results: The most significant cluster in all comparisons was cluster 13 identified in the Salt-No Salt comparison with a regression coefficient (w) of -46.76. Functional and Canonical pathway analysis of cluster 13 in IPA implicated transcriptional activation and circadian rhythm signalling, respectively. Salt-NoSalt renal expression profiles validated by qRT-PCR from each of the strain comparisons identified significant genes in the 2a and WKY strains that were not changing in the SHRSP including 4 transcription factors (TF) (Arntl, Bhlhe41, Nfil3 and NPAS2). Potential upstream regulatory factors of this cluster 13, mapping to the congenic interval on chromosome 2, were identified including Arnt, mir9–1 and mir9–2. Conclusion: Meta-covariate analysis identifies genes involved in transcriptional activation and circadian rhythm which may contribute to the enhanced salt sensitivity in the SHRSP compared to the 2a and WKY strains.
    Fold change
    A Schwann cell has regenerative capabilities and is an important cell in the peripheral nervous system. This microarray study is part of a bioinformatics study that focuses mainly on Schwann cells. Microarray data provide information on differences between microarray-based and experiment-based gene expression analyses. According to microarray data, several genes exhibit increased expression (fold change) but they are weakly expressed in experimental studies (based on morphology, protein and mRNA levels). In contrast, some genes are weakly expressed in microarray data and highly expressed in experimental studies; such genes may represent future target genes in Schwann cell studies. These studies allow us to learn about additional genes that could be used to achieve targeted results from experimental studies. In the current big data study by retrieving more than 5000 scientific articles from PubMed or NCBI, Google Scholar, and Google, 1016 (up- and downregulated) genes were determined to be related to Schwann cells. However, no experiment was performed in the laboratory; rather, the present study is part of a big data analysis. Our study will contribute to our understanding of Schwann cell biology by aiding in the identification of genes. Based on a comparative analysis of all microarray data, we conclude that the microarray could be a good tool for predicting the expression and intensity of different genes of interest in actual experiments.
    Schwann cell
    Gene chip analysis
    Microarray databases
    Citations (9)
    Murine transplantation models are used extensively to research immunological rejection and tolerance. Here we studied both murine heart and liver allograft models using microarray technology. We had difficulty in identifying genes related to acute rejections expressed in both heart and liver transplantation models using two standard methodologies: Student's t test and linear models for microarray data (Limma). Here we describe a new method, standardized fold change (SFC), for differential analysis of microarray data. We estimated the performance of SFC, the t test and Limma by generating simulated microarray data 100 times. SFC performed better than the t test and showed a higher sensitivity than Limma where there is a larger value for fold change of expression. SFC gave better reproducibility than Limma and the t test with real experimental data from the MicroArray Quality Control platform and expression data from a mouse cardiac allograft. Eventually, a group of significant overlapping genes was detected by SFC in the expression data of mouse cardiac and hepatic allografts and further validated with the quantitative RT-PCR assay. The group included genes for important reactions of transplantation rejection and revealed functional changes of the immune system in both heart and liver of the mouse model. We suggest that SFC can be utilized to stably and effectively detect differential gene expression and to explore microarray data in further studies.
    Gene chip analysis
    Fold change
    Microarray databases
    Citations (3)