Microrna expression (Agilent McroRNA Array)
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Li Bing
PROVIDER: S-ECPF-MTAB-1327 | biostudies-other |
REPOSITORIES: biostudies-other
Similar Datasets
Project description:BackgroundThe Agilent microRNA microarray platform interrogates each microRNA with several copies of distinct oligonucleotide probes and integrates the results into a total gene signal (TGS), using a proprietary algorithm that makes use of the background subtracted signal. The TGS can be normalized between arrays, and the Agilent recommendation is either not to normalize or to normalize to the 75th percentile signal intensity. The robust multiarray average algorithm (RMA) is an alternative method, originally developed to obtain a summary measure of mRNA Affymetrix gene expression arrays by using a linear model that takes into account the probe affinity effect. The RMA method has been shown to improve the accuracy and precision of expression measurements relative to other competing methods. There is also evidence that it might be preferable to use non-corrected signals for the processing of microRNA data, rather than background-corrected signals. In this study we assess the use of the RMA method to obtain a summarized microRNA signal for the Agilent arrays.FindingsWe have adapted the RMA method to obtain a processed signal for the Agilent arrays and have compared the RMA summarized signal to the TGS generated with the image analysis software provided by the vendor. We also compared the use of the RMA algorithm with uncorrected and background-corrected signals, and compared quantile normalization with the normalization method recommended by the vendor. The pre-processing methods were compared in terms of their ability to reduce the variability (increase precision) of the signals between biological replicates. Application of the RMA method to non-background corrected signals produced more precise signals than either the RMA-background-corrected signal or the quantile-normalized Agilent TGS. The Agilent TGS normalized to the 75% percentile showed more variation than the other measures.ConclusionsUsed without background correction, a summarized signal that takes into account the probe effect might provide a more precise estimate of microRNA expression. The variability of quantile normalization was lower compared with the normalization method recommended by the vendor.
| S-EPMC2823597 | biostudies-literature
Project description:BackgroundThe main research tool for identifying microRNAs involved in specific cellular processes is gene expression profiling using microarray technology. Agilent is one of the major producers of microRNA arrays, and microarray data are commonly analyzed by using R and the functions and packages collected in the Bioconductor project. However, an analytical package that integrates the specific characteristics of microRNA Agilent arrays has been lacking.ResultsThis report presents the new bioinformatic tool AgiMicroRNA for the pre-processing and differential expression analysis of Agilent microRNA array data. The software is implemented in the open-source statistical scripting language R and is integrated in the Bioconductor project (http://www.bioconductor.org) under the GPL license. For the pre-processing of the microRNA signal, AgiMicroRNA incorporates the robust multiarray average algorithm, a method that produces a summary measure of the microRNA expression using a linear model that takes into account the probe affinity effect. To obtain a normalized microRNA signal useful for the statistical analysis, AgiMicroRna offers the possibility of employing either the processed signal estimated by the robust multiarray average algorithm or the processed signal produced by the Agilent image analysis software. The AgiMicroRNA package also incorporates different graphical utilities to assess the quality of the data. AgiMicroRna uses the linear model features implemented in the limma package to assess the differential expression between different experimental conditions and provides links to the miRBase for those microRNAs that have been declared as significant in the statistical analysis.ConclusionsAgiMicroRna is a rational collection of Bioconductor functions that have been wrapped into specific functions in order to ease and systematize the pre-processing and statistical analysis of Agilent microRNA data. The development of this package contributes to the Bioconductor project filling the gap in microRNA array data analysis.
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Project description:MicroRNA profiling of 3 Human NSCLC cell lines (PC9,PC9R,H1975)
2013-10-01 | E-MTAB-1327 | biostudies-arrayexpress
Project description:BackgroundMicroRNAs (miRNAs) are approximately 22-nt small non-coding RNAs that regulate the expression of specific target genes in many eukaryotes. In higher plants, miRNAs are involved in developmental processes and stress responses. Sexual reproduction in flowering plants relies on pollen, the male gametophyte, to deliver sperm cells to fertilize the egg cell hidden in the embryo sac. Studies indicated that post-transcriptional processes are important for regulating gene expression during pollen function. However, we still have very limited knowledge on the involved gene regulatory mechanisms. Especially, the function of miRNAs in pollen remains unknown.ResultsUsing miRCURY LNA array technology, we have profiled the expression of 70 known miRNAs (representing 121 miRBase IDs) in Arabidopsis mature pollen, and compared the expression of these miRNAs in pollen and young inflorescence. Thirty-seven probes on the array were identified using RNAs isolated from mature pollen, 26 of which showed significant differences in expression between mature pollen and inflorescence. Real-time PCR based on TaqMan miRNA assays confirmed the expression of 22 miRNAs in mature pollen, and identified 8 additional miRNAs that were expressed at low level in mature pollen. However, the expression of 11 miRNA that were identified on the array could not be confirmed by the Taqman miRNA assays. Analyses of transcriptome data for some miRNA target genes indicated that miRNAs are functional in pollen.ConclusionIn summary, our results showed that some known miRNAs were expressed in Arabidopsis mature pollen, with most of them being low abundant. The results can be utilized in future research to study post-transcriptional gene regulation in pollen function.
| S-EPMC2715406 | biostudies-literature
Project description:Agilent 44K whole genome studies were used to correlate gene expression values with mutations found in massively parallel sequencing experiments. 77 patients were profiled using Agilent's two-color microarray platform. Tumor(cy5) was co-hybridized to a reference(cy3).
| S-ECPF-GEOD-29442 | biostudies-other
Project description:MicroRNA Analysis of TCGA OVA samples using Agilent MicroRNA array
2016-12-22 | GSE92683 | GEO
Project description:HMGA2 has been implicated in tumor progression. Identification of microRNAs regulated by HMGA2 helps us to understand how HMGA2 regulates tumor metastasis via its downstream target mircoRNAs and genes. Total RNA was extracted from 1833 cells with control or depleted HMGA2 expression, respectively. Exiqon miRCURY LNA 5th generation expression array was performed to identify the microRNAs regulated by HMGA2.
| S-ECPF-GEOD-43739 | biostudies-other
Project description:RKIP has been implicated in suppression of breast tumor metastasis. Identification of microRNAs regulated by RKIP helps us to understand how RKIP suppresses tumor metastasis via its downstream target mircoRNAs and genes. Total RNA was extracted from 1833 cells expressing RKIP or control, respectively. Exiqon miRCURY LNA array v.11.0. was performed to identify the microRNAs regulated by RKIP.
| S-ECPF-GEOD-47366 | biostudies-other
Project description:We have investigated the effect of exposure to 150 mg/kg benzo(a)pyrene (BaP) for 3 days on mRNA and miRNA expression levels in adult mouse liver. We used Agilent miRNA array platforms to assess effects of BaP exposure on miRNA expression levels. Our results indicate a distinct lack of effect of BaP of miRNA expression, despite widespread changes in mRNA levels. The data in the attached array files were used a positive control for the Agilent platform, to indicate that the platform was able to detect significant differences in abundance of miRNA between two samples with great differences in miRNA content. Keywords: Toxicology, miRNA
2010-10-28 | GSE19438 | GEO
Project description:To investigate the gene expression in human corneal epithelial overexpressing hsa-miR-145 by transfection , we have employed Whole Human Genome Oligo Microarray (Agilent) as a screening platform to identify gene regulation. We discovered a differential gene expression in HCE cells transfected with hsa-mIR-145 against cells with scrambled sequences. Among them, genes related with corneal development, integrity, differentiation and inflammatory responses were found and this was validated by real-time PCR.
2011-10-10 | GSE24980 | GEO