Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA313023 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Defining molecular features that can predict the recurrence of colorectal cancer (CRC) for stage II-III patients remains challenging in cancer research. Most available clinical samples are Formalin-Fixed and Paraffin-Embedded (FFPE). NanoString nCounter® and Affymetrix GeneChip® Human Transcriptome Array 2.0 (HTA) are the two platforms marketed for high-throughput gene expression profiling for FFPE tissue samples. In this study, to identify an optimal platform for the gene expression profiling of FFPE CRC samples, we evaluated the expression of 516 genes from published frozen tissue-derived prognostic signatures in 42 CRC patient samples measured by these two platforms. Based on HTA platform-derived data, we identified both gene (99 individual genes, FDR < 0.05) and gene set (four of the six reported multi-gene signatures with sufficient information for evaluation, P < 0.05) expression differences associated with survival outcomes. Using nCounter platform-derived data, only one of the six multi-gene signatures (P < 0.05) but no individual gene was associated with survival outcomes. Therefore, the HTA appears to provide a more robust gene expression dataset using genes from published gene signatures. Our study indicated that sufficiently high quality RNA could be obtained from FFPE tumor tissues to detect frozen tissue-derived prognostic gene expression signatures for CRC patients.
2016-08-31 | GSE78248 | GEO
Project description:The prognosis of colorectal cancer (CRC) stage II and III patients is still a challenge due to the difficulties of finding robust biomarkers and assays. The majority of published gene signatures of CRC have been generated on frozen colorectal tissues. Because collection of fresh frozen tissues is not routine and the quantity and quality of RNA derived from formalin-fixed paraffin-embedded (FFPE) tissues is vastly inferior to that derived from fresh frozen tissue, a clinical test for improving staging of colon cancer will need to be designed for FFPE tissues in order to be widely applicable. We have designed a custom Nanostring nCounter assay for quantitative assessment of expression of 414 gene elements consisting of multiple published gene signatures for colon cancer prognosis, and systematically compared the gene expression quantification between nCounter data from FFPE and Affymetrix microarray array data from matched frozen tissues using 414 genes.
2015-10-27 | GSE62932 | GEO
Project description:The prognosis of colorectal cancer (CRC) stage II and III patients is still a challenge due to the difficulties of finding robust biomarkers and assays. The majority of published gene signatures of CRC have been generated on frozen colorectal tissues. Because collection of fresh frozen tissues is not routine and the quantity and quality of RNA derived from formalin-fixed paraffin-embedded (FFPE) tissues is vastly inferior to that derived from fresh frozen tissue, a clinical test for improving staging of colon cancer will need to be designed for FFPE tissues in order to be widely applicable. We have designed a custom Nanostring nCounter assay for quantitative assessment of expression of 414 gene elements consisting of multiple published gene signatures for colon cancer prognosis, and systematically compared the gene expression quantification between nCounter data from FFPE and Affymetrix microarray array data from matched frozen tissues using 414 genes. For microarray studies, representative sections of fresh tissue specimens were flash frozen in liquid nitrogen and stored at â80°C until RNA isolation. RNA was purified from tissue sections containing >80% epithelial tumor tissue using RNeasy (QIAGEN, Valencia, CA) according to manufacturerâs instructions. Samples were hybridized to Affymetrix arrays Human Genome U133 Plus 2.0 GeneChip Expression Arrays, Santa Clara, CA). The samples included four healthy control patient tissues, 12 stage I, 17 stage II, 20 stage III and 15 stage IV CRC patient tissues. Please note that only the *matched.csv files containing matched 414 genes' microarray and nanostring data are provided without the nanostring experimental descriptions. The matching samples between GSE62932 and the Nanostring study are indicated in the matching_samples.txt.
2015-10-27 | E-GEOD-62932 | biostudies-arrayexpress
Project description:Purpose: Gene expression signatures developed to measure the activity of oncogenic signaling pathways have been used to dissect the heterogeneity of tumor samples and to predict sensitivity to various cancer drugs that target components of the relevant pathways, thus potentially identifying therapeutic options for subgroups of patients. To facilitate broad use, including in a clinical setting, the ability to generate data from formalin-fixed, paraffin-embedded (FFPE) tissues is essential. Experimental Design: Patterns of pathway activity in matched fresh-frozen and FFPE xenograft tumor samples were generated using the MessageAmp Premier methodology in combination with assays using Affymetrix arrays. Results generated were compared with those obtained from fresh-frozen samples using a standard Affymetrix assay. In addition, gene expression data from patient matched fresh-frozen and FFPE melanomas were also utilized to evaluate the consistency of predictions of oncogenic signaling pathway status. Results: Significant correlation of pathway activity predictions was observed between paired fresh-frozen and FFPE xenograft tumor samples. In addition, significant concordance of pathway activity predictions was also observed between patient matched fresh-frozen and FFPE melanomas. Conclusion: Reliable and consistent predictions of oncogenic pathway activities can be obtained from FFPE tumor tissue samples. The ability to reliably utilize FFPE patient tumor tissue samples for genomic analyses will lead to a better understanding of the biology of disease progression and, in the clinical setting, will provide tools to guide the choice of therapeutics to those most likely to be effective in treating a patient’s disease.
2011-06-24 | GSE29598 | GEO
Project description:Chromosomal instable colorectal cancer is marked by specific large chromosomal copy number aberrations. Recently, focal aberrations of 3Mb or smaller have been identified as a common phenomenon in cancer. Inherent to their limited size, these aberrations harbour one or few genes. The aim of this study is to identify recurrent focal chromosomal aberrations and their candidate driver genes in a well defined series of stage II colon cancers and assess their potential clinical relevance. High resolution DNA copy number profiles were obtained from 38 formalin fixed paraffin embedded colon cancer samples with matched normal mucosa as a reference using array comparative genomic hybridization. In total, 81 focal chromosomal aberrations were identified that harboured 177 genes. Statistical validation of focal aberrations and identification of candidate driver genes was performed by enrichment analysis and mapping copy number and mutation data of colorectal-, breast-, pancreatic cancer and glioblastomas to loci of focal aberrations in stage II colon cancer. This analysis demonstrated a significant overlap with previously identified focal amplifications in colorectal cancer, but not with cancers from other sites. In contrast, focal deletions seem less tumour type specific since they also show significant overlap with focal deletions of other sites. Focal deletions detected are significantly enriched for cancer genes and genes frequently mutated in colorectal cancer. The mRNA expression of these genes is significantly correlated with DNA copy number status, supporting the relevance of focal aberrations. Loss of 5q34 and gain of 13q22.1 were identified as independent prognostic factors of survival in this series of patients. In conclusion, focal chromosomal copy number aberrations in stage II colon cancer are enriched in cancer genes which contribute to and drive the process of colorectal cancer development. DNA copy number status of these genes correlate with mRNA expression and some are associated with clinical outcome. 38 Stage II colorectal cancer (CRC) tissue samples (FFPE) of which 19 were done on expression arrays. One sample (Stage II colorectal cancer tissue samples (FFPE) 26) was also done on the 135K NimbleGen array. Fresh frozen and FFPE of the same CRC stage I sample was done on 105K agilent. The fresh frozen was across array in silico set out against a pool of blood of 18 healthy females.
2010-04-19 | E-GEOD-17047 | biostudies-arrayexpress
Project description:Formalin-fixed paraffin-embedded (FFPE) samples are a highly desirable resource for epigenetic studies, but there is no suitable platform to assay genome-wide methylation in these widely available resources. Recently, Thirwell et al. (2010) have reported a modified ligation-based DNA repair protocol to prepare FFPE DNA for the Infinium methylation assay. In this study, we have tested the accuracy of methylation data obtained with this modification by comparing paired fresh-frozen (FF) and FFPE colon tissue from colorectal cancer patients. We report locus-specific correlation and concordance of tumor-specific differentially-methylated loci (DML), both of which were not previously assessed.
2014-10-23 | GSE33181 | GEO
Project description:We applied DNA content based flow cytometry methods to interrogate the genomes of clinical samples from 21 patients with early onset colorectal carcinoma (EOCRC). These included a fresh frozen sample obtained from a surgical resection and 20 archived formalin fixed paraffin embedded (FFPE) samples from a Mayo Clinic tissue bank. Our flow sorting methods are compatible with analyses of biopsies of interest including FFPE samples and frozen biopsies. Notably for this study we distinguished and sorted diploid and aneuploid tumors. We then profiled the exomes of tumor normal pairs for all 21 cases, the whole genome copy number for a subset of 6 samples, and telomere length in diploid and aneuploid nuclei from 9 cases. Additionally, we screened the 20 FFPE cases for EGFR expression with an established IHC assay.
2024-02-21 | GSE240339 | GEO
Project description:Total RNA was extracted from FFPE samples of 139 chemotherapy-naïve hormone-receptor-negative breast cancers pooled from three sample sources and assayed for the expression of 21 genes within two previously reported microarray-derived prognostic signatures in 6 RT-PCR multiplexes.
2013-10-25 | GSE51630 | GEO
Project description:Customized Nanostring PanCancer Progression Panel performed on FFPE tumor tissue derived from treatment naive metastatic colorectal cancer patients included into the randomized phase 2 PanaMa trial.
2023-02-15 | GSE221953 | GEO
Project description:MicroRNAs regulate several aspects of tumorigenesis and cancer progression. Most cancer tissues are archived formalin-fixed and paraffin-embedded (FFPE). While microRNAs are a more stable form of RNA thought to withstand FFPE-processing and degradation there is only limited evidence for the latter assumption. We examined whether microRNA profiling can be successfully conducted on FFPE cancer tissues using SOLiD ligation based sequencing. Tissue storage times (3-9 years) appeared to not affect the number of detected microRNAs in FFPE samples compared to matched frozen samples (paired t-test p>0.7). Correlations of microRNA expression values were very high across microRNAs in a given sample (Pearson’s r=0.71-0.95). Higher variance of expression values among samples was associated with higher correlation coefficients between FFPE and frozen tissues. One of the FFPE samples in this study was degraded for unknown reasons with a peak read length of 17 nucleotides compared to 21 in all other samples. The number of detected microRNAs in this sample was within the range of microRNAs detected in all other samples. Ligation-based microRNA deep sequencing on FFPE cancer tissues is feasible and RNA degradation to the degree observed in our study appears to not affect the number of microRNAs that can be quantified.
2013-04-15 | GSE45740 | GEO