Circulating miRNA microarray analysis from archival plasma samples
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE42654 | GEO | 2013/04/23
SECONDARY ACCESSION(S): PRJNA182748
REPOSITORIES: GEO
Similar Datasets
Project description:Using a microarray-based method we report on: i) adequate intra- and interarray reproducibility of miRNA profiling; ii) feasibility of using archival plasma samples stored for an extended period of time and available in limited amounts; and iii) good correlation between different batches. A total of 11 archived plasma samples collected between 1988 and 1999 were evaluated in this study. Firstly, RNA extracted from two samples (S1 and S2) were hybridized in triplicate. The same samples were also hybridized in triplicate after increasing the starting material volume from 2 to 2.5. Nine additional plasma samples were processed and RNA was hybridized on two different batches of arrays. Finally, two samples (S3 and S4) were re-hybridized on an array of the same batch of the first hybridization but close to the chip expiration date.
2013-04-23 | E-GEOD-42654 | biostudies-arrayexpress
Project description:BACKGROUND: Array Comparative Genomic Hybridization (aCGH) is a rapidly evolving technology that still lacks complete standardization. Yet, it is of great importance to obtain robust and reproducible data to enable meaningful multiple hybridization comparisons. Special difficulties arise when aCGH is performed on archival formalin-fixed, paraffin-embedded (FFPE) tissue due to its variable DNA quality. Recently, we have developed an effective DNA quality test that predicts suitability of archival samples for BAC aCGH. METHODS: In this report, we first used DNA from a cancer cell-line (SKBR3) to optimize the aCGH protocol for automated hybridization, and subsequently optimized and validated the procedure for FFPE breast cancer samples. We aimed for highest throughput, accuracy, and reproducibility applicable to FFPE samples, which can also be important in future diagnostic use. RESULTS: Our protocol of automated array-CGH on archival FFPE ULS-labeled DNA showed very similar results compared with published data and our previous manual hybridization method. CONCLUSION: This report combines automated aCGH on unamplified archival FFPE DNA using non-enzymatic ULS labeling, and describes an optimized protocol for this combination resulting in improved quality and reproducibility.
2007-02-23 | GSE7122 | GEO
Project description:Over 20 million archival tissue samples are stored annually in the United States as formalin-fixed, paraffin-embedded (FFPE) tissue blocks, but only recently has whole-genome expression profiling from these samples become technically feasible. Here, we introduce novel general methods for assessing, summarizing, and visualizing expression data quality from archival samples. We validated these methods in technical study of 144 clinical breast cancer and autopsy samples and in an overview of all current publicly available FFPE whole-genome expression data. We additionally performed a case study incorporating over 1,000 colorectal cancer (CRC) samples collected from patients across the United States over a period of more than 25 years, integrating clinicopathological information, tumor molecular data, and archival tissue gene expression on an unparalleled scale. Both large-scale clinical studies presented a much greater range of data quality than previous smaller studies, emphasizing the need for rigorous quality control in translational applications of archival tissue gene expression profiling.
2012-10-02 | GSE32651 | GEO
Project description:BACKGROUND: Array Comparative Genomic Hybridization (aCGH) is a rapidly evolving technology that still lacks complete standardization. Yet, it is of great importance to obtain robust and reproducible data to enable meaningful multiple hybridization comparisons. Special difficulties arise when aCGH is performed on archival formalin-fixed, paraffin-embedded (FFPE) tissue due to its variable DNA quality. Recently, we have developed an effective DNA quality test that predicts suitability of archival samples for BAC aCGH. METHODS: In this report, we first used DNA from a cancer cell-line (SKBR3) to optimize the aCGH protocol for automated hybridization, and subsequently optimized and validated the procedure for FFPE breast cancer samples. We aimed for highest throughput, accuracy, and reproducibility applicable to FFPE samples, which can also be important in future diagnostic use. RESULTS: Our protocol of automated array-CGH on archival FFPE ULS-labeled DNA showed very similar results compared with published data and our previous manual hybridization method. CONCLUSION: This report combines automated aCGH on unamplified archival FFPE DNA using non-enzymatic ULS labeling, and describes an optimized protocol for this combination resulting in improved quality and reproducibility. In this study, we optimized the BAC araay-CGH protocol for automated hybridization for FFPE breast cancer samples. We have tested hybridization temperature and duration, different hybridization buffer conditions, and post-hybridization washing.
2010-06-12 | E-GEOD-7122 | biostudies-arrayexpress
Project description:Over 20 million archival tissue samples are stored annually in the United States as formalin-fixed, paraffin-embedded (FFPE) tissue blocks, but only recently has whole-genome expression profiling from these samples become technically feasible. Here, we introduce novel general methods for assessing, summarizing, and visualizing expression data quality from archival samples. We validated these methods in technical study of 144 clinical breast cancer and autopsy samples and in an overview of all current publicly available FFPE whole-genome expression data. We additionally performed a case study incorporating over 1,000 colorectal cancer (CRC) samples collected from patients across the United States over a period of more than 25 years, integrating clinicopathological information, tumor molecular data, and archival tissue gene expression on an unparalleled scale. Both large-scale clinical studies presented a much greater range of data quality than previous smaller studies, emphasizing the need for rigorous quality control in translational applications of archival tissue gene expression profiling. This series includes 1,003 FFPE-preserved CRC tumors, assayed by Illumina HumanRef-v3 WG-DASL microarray.
2012-10-02 | E-GEOD-32651 | biostudies-arrayexpress
Project description:RNA extracted from 78 FFPE tongue samples, 62 tongue carcinomas and 16 non-malignant controls, were succesfully analysed using the whole genome DASL array to obtain gene expression profiles. Gene expression profiles were used to identify differentially expressed genes with the ultimate goal of finding out their importance for tongue cancer development and maintenance. Sample were formalin fixed paraffin embedded biopsies taken for diagnostic purposes and had been stored between 1 and 13 years. Because of the general poor quality of RNA from archival samples a special focus were put on its effect on the detected expression levels. 28 tumours and 16 controls with a CTdiff< 5 were selected for differential gene expression analysis. Raw data for only these samples were normalized again. Data for these 44 samples can be found here.
2012-05-11 | GSE34106 | GEO
Project description:RNA extracted from 78 FFPE tongue samples, 62 tongue carcinomas and 16 non-malignant controls, were succesfully analysed using the whole genome DASL array to obtain gene expression profiles. Gene expression profiles were used to identify differentially expressed genes with the ultimate goal of finding out their importance for tongue cancer development and maintenance. Sample were formalin fixed paraffin embedded biopsies taken for diagnostic purposes and had been stored between 1 and 13 years. Because of the general poor quality of RNA from archival samples a special focus were put on its effect on the detected expression levels. 28 tumours and 16 controls with a CTdiff< 5 were selected for differential gene expression analysis. Data for only these sample were normalized again and can be found in seperate data file.
2012-05-11 | GSE34105 | GEO
Project description:We developed a novel approach to isolate tumor cells with high purity from blood via immunomagnetic enrichment followed by fluorescence activated cell sorting (IE/FACS) and examined copy number alterations in these cells. Magnetic beads coated with EpCAM mAb were added to blood to enrich for tumor cells. Enriched samples were then subjected to FACS analysis using differentially labeled mAbs to distinguish tumor cells (EpCAM+) from leukocytes (CD45+) during sorting. DNA from isolated tumor cells was subjected to whole genome amplification (WGA) and copy number analysis via array comparative genomic hybridization (CGH). The assay was evaluated using BT474 and MCF7 breast cancer cell lines and in CTCs from 5 metastatic breast cancer (MBC) patients with matched archival primary tumors and later extended to an additional 97 MBC patients. Evaluation of the assay on isolated breast cancer cell lines spiked into blood correctly identified the known genomic alterations with high reproducibility. In clinical studies, comparison of CTCs with matched archival primary tumors confirmed shared lineage with notable divergence. In addition, serial testing of CTCs confirmed reproducibility, and indicated genomic change over time. Analysis of genomic profiles of CTCs from 102 MBC patients revealed common copy number alterations including gains in 1q and 8q and losses in 8p and 11q. Comparison with a published CGH dataset of primary breast tumors revealed similar frequencies of recurrent genomic copy number aberrations.
2012-12-31 | E-GEOD-27511 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the following subset Series: GSE34105: Gene expression profiling of archival tongue carcinoma and normal tongue tissue (all samples) GSE34106: Gene expression profiling of archival tongue carcinoma and normal tongue tissue (subset) Refer to individual Series
2012-05-10 | E-GEOD-34115 | biostudies-arrayexpress
Project description:Formalin-fixed paraffin-embedded (FFPE) samples are the only remaining biological archive for many toxicological and clinical studies, yet their use in genomics has been limited due to variability in RNA quality from formalin fixation. Older FFPE samples, which often have highly degraded RNA, pose a particularly difficult technical challenge. Recent developments in probe-based targeted sequencing technologies show promise in addressing this issue, while also being more cost effective than traditional RNA-sequencing (RNA-seq) methods. In the current study, we evaluated dose-dependent transcriptional changes from paired frozen and archival FFPE liver samples stored for over 20 years using targeted resequencing (TempO-Seq) and whole-genome RNA-seq methods. Samples were originally collected from male mice exposed to a reference chemical (dichloroacetic acid, DCA) at 0, 198, 313 and 427 mg/kg-day, (n=6/dose) by drinking water for 6 days. TempO-Seq showed high overlap in differentially expressed genes (DEGs) between matched FFPE and flash-frozen (FROZ) samples and concordance in fold-changes across the highest two dose levels of DCA vs. control (R2 ≥ 0.94). Similarly, high concordance in fold-changes was observed between TempO-Seq FFPE and RNA-seq FROZ results (R2 ≥ 0.92). Only 28 DEGs or fewer were identified in RNA-seq FFPE samples. Modeling of DCA-dependent changes in gene sets identified benchmark doses from TempO-Seq FROZ and FFPE samples that were within 1.4-fold of RNA-seq FROZ samples (93.9 mg/kg-d), whereas RNA-seq FFPE samples were 3.3-fold higher (310.3 mg/kg-d). This work demonstrates that targeted sequencing may provide a more robust method for quantifying gene expression profiles from aged archival FFPE samples.
2022-10-10 | GSE186113 | GEO