Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA255739 | ENA |
REPOSITORIES: ENA
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Project description:Formalin-fixed paraffin-embedded (FFPE) tissues are a vast resource of annotated clinical samples. As such, they represent highly desirable and informative materials for the application of high-definition genomics for improved patient management and to advance the development of personalized therapeutics. However, a limitation of FFPE tissues is the variable quality of DNA extracted for analyses. Furthermore, admixtures of non-tumor and polyclonal neoplastic cell populations limit the number of biopsies that can be studied and make it difficult to define cancer genomes in patient samples. To exploit these valuable tissues, we applied flow cytometry-based methods to isolate pure populations of tumor cell nuclei from FFPE tissues and developed a methodology compatible with oligonucleotide array CGH and whole exome sequencing analyses. These were used to profile a variety of tumors (breast, brain, bladder, ovarian and pancreas), including the genomes and exomes of matching fresh frozen and FFPE pancreatic adenocarcinoma samples.
2012-12-31 | GSE40299 | GEO
Project description:Formalin-fixed paraffin-embedded (FFPE) tissues are a vast resource of annotated clinical samples. As such, they represent highly desirable and informative materials for the application of high-definition genomics for improved patient management and to advance the development of personalized therapeutics. However, a limitation of FFPE tissues is the variable quality of DNA extracted for analyses. Furthermore, admixtures of non-tumor and polyclonal neoplastic cell populations limit the number of biopsies that can be studied and make it difficult to define cancer genomes in patient samples. To exploit these valuable tissues, we applied flow cytometry-based methods to isolate pure populations of tumor cell nuclei from FFPE tissues and developed a methodology compatible with oligonucleotide array CGH and whole exome sequencing analyses. These were used to profile a variety of tumors (breast, brain, bladder, ovarian and pancreas), including the genomes and exomes of matching fresh frozen and FFPE pancreatic adenocarcinoma samples. A total of 23 test samples were each hybridized with a pooled 46,XX commercial reference (Promega catalog# G1521, Madison, WI). Twenty-two of the test samples included flow-sorted fresh frozen and formalin-fixed paraffin-embedded tumor samples. The tissues included pancreatic adenocarcinomas, breast carcinomas, small cell carcinoma of the ovary, glioblastoma, and bladder carcinoma. The last test sample was a pancreatic adenocarcinoma cell line (A10-74).
2012-12-31 | E-GEOD-40299 | biostudies-arrayexpress
Project description:Advantages of RNA-Seq over array based platforms are quantitative gene expression and discovery of expressed single nucleotide variants (eSNVs) and fusion transcripts from a single platform, but the sensitivity for each of these characteristics is unknown. We measured gene expression in a set of manually degraded RNAs, nine pairs of matched fresh-frozen, and FFPE RNA isolated from breast tumor with the hybridization based, NanoString nCounter, (226 gene panel) and with whole transcriptome RNA-Seq using RiboZeroGold ScriptSeq V2 library preparation kits. We performed correlation analyses of gene expression between samples and across platforms. We then specifically assessed whole transcriptome expression of lincRNA and discovery of eSNVs and fusion transcripts in the FFPE RNA-Seq data. For gene expression in the manually degraded samples, we observed Pearson correlation of >0.94 and >0.80 with NanoString and ScriptSeq protocols respectively. Gene expression data for matched fresh-frozen and FFPE samples yielded mean Pearson correlations of 0.874 and 0.783 for NanoString (226 genes) and ScriptSeq whole transcriptome protocols respectively. Specifically for lincRNAs, we observed superb Pearson correlation (0.988) between matched fresh-frozen and FFPE pairs. FFPE samples across NanoString and RNA-Seq platforms gave a mean Pearson correlation of 0.838. In FFPE libraries, we detected 53.4% of high confidence SNVs and 24% of high confidence fusion transcripts. Sensitivity of fusion transcript detection was not overcome by an increase in depth of sequencing up to 3-fold (increase from ~56 to ~159 million reads). Both NanoString and ScriptSeq RNA-Seq technologies yield reliable gene expression data for degraded and FFPE material. The high degree of correlation between NanoString and RNA-Seq platforms suggests discovery based whole transciptome studies from FFPE material will produce reliable expression data. The RiboZeroGold ScriptSeq protocol performed particularly well for lincRNA expression from FFPE libraries but detection of eSNV and fusion transcripts was less sensitive.
2013-12-06 | GSE51124 | GEO
Project description:Background: Archival formalin-fixed, paraffin-embedded (FFPE) tissue samples with clinical and histological data are a singularly valuable resource for developing new molecular biomarkers. However, transcriptome analysis remains challenging with standard mRNA-seq methods as FFPE derived-RNA samples are often highly modified and fragmented. The recently developed 3’ mRNA-seq method sequences the 3’ region of mRNA using unique molecular identifiers (UMI), thus generating gene expression data free from PCR amplification bias. In this study, we evaluated the performance of the 3’ mRNA-Seq using Lexogene QuantSeq 3’ mRNA-Seq Library Prep Kit FWD with UMI, comparing with TruSeq stranded mRNA-Seq and RNA Exome Capture. The fresh-frozen (FF) and FFPE tissues yielded nucleotide sizes range from 13% to >70% of DV200 values; input amounts ranged from 1ng to 100ng for validation. Results: The total mapped reads of the 3’ mRNA-Seq to the reference genome ranged from 99% to74% across all the samples. After PCR bias correction, total mapped reads ranged from 3% to 56%. The 3’ mRNA-Seq data showed highly reproducible data in the UHR (R>0.94) at different input amounts from 1ng to 100ng, and FF and FFPE paired samples (R=0.93) at 10 ng. Severely degraded FFPE RNA with 13% to 30% of DV200 value showed good concordance (R>0.90) with 100ng input. A moderate correlation was observed when directly comparing 3’ mRNA-Seq data with TruSeq stranded mRNA-Seq (R=0.78) and RNA Exome Capture data (R>0.67). Conclusion: In this study, 3’ mRNA-Seq with PCR bias correction using UMI is a suitable method for gene quantification in both FF and FFPE RNAs. The 3’ mRNA-Seq may be applied to severely degraded RNA from FFPE tissues and generate high-quality sequencing data.
2021-10-28 | GSE173506 | GEO
Project description:For the effectiveness of targeted immunotherapy, which is currently one of the most promising treatments for brain tumors, it is necessary to know specific tumor-associated antigens (TAA). This project aimed to validate the suitability of formalin-fixed and paraffin-embedded (FFPE) material instead of fresh-frozen material for RNA sequencing and downstream TAA identification. Purpose: Detect potential oligodendroglioma-associated antigens using both fresh-frozen and FFPE brain tissues; assess the suitability of the FFPE material for TAA identification. Results: A comparative analysis based on the RNA-seq of canine oligodendroglioma showed that formalin fixation of the samples had a significant effect on the RNA-seq library in terms of quality. Read distribution analysis showed that the FFPE samples contained fewer reads mapping to exonic regions and were enriched with reads mapped to introns and intergenic regions, while the fresh-frozen samples were mostly enriched in reads mapping to exons. Mismatch profile and SNVs calling analyses revealed some substitution artefacts present in the FFPE samples and absent in the corresponding fresh-frozen samples. However, according to the Principal Component Analysis, 36% of the variance between the samples could be explained by the types of conservation, while 43% of the variance could still be attributed to different expression profiles between oligodendroglioma and control conditions. A differential expression analysis of fresh-frozen oligodendroglioma versus fresh-frozen control samples identified 62 potential TAA strongly up-regulated in tumor tissue. The same analysis using the FFPE samples showed 80% of these genes (49/62) also to be differentially expressed. Comparative analysis showed good agreement between FFPE and fresh-frozen RNA-seq libraries in terms of the accuracy of gene expression measurements indicating that archived FFPE tissue can be used for identification of TAA candidates by RNA-seq providing a wealthy source of clinical samples for research. The following 10 genes encoding cell surface proteins have been identified by both approaches as potential TAA candidates based on their strong overexpression in oligodendrogliomas: PDGFRA, NOTCH1, DLL1, GPER1, TNR, IQGAP3, CD44, ERBB3, BCAS1 and ROR2. Future projects still need to investigate their suitability as TAA for targeted immunotherapy. Conclusion: Formalin fixation of the samples had a significant impact on the RNA-seq quality in terms of the accuracy of gene expression measurements, as well as the quality of the nucleotide sequences. Nevertheless, the comparative analysis showed good agreement between FFPE and fresh-frozen RNA-seq libraries.
2020-10-27 | GSE160124 | GEO
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:Tissue sample acquisition is a limiting step in many studies. There are many thousands of formalin fixed paraffin embedded archival blocks collected around the world, but in contrast relatively few fresh frozen samples in tumor banks. Once samples are fixed in formalin the RNA is degraded and traditional methods for gene expression profiling are not suitable. In this study we have evaluated the whole genome DASL assay from Illumina to perform transcriptomic analysis from archived breast tumor tissue fixed in formalin paraffin embedded blocks. We profiled 76 familial breast tumors from cases carrying a BRCA1, BRCA2 or ATM mutation, or from non-BRCA1/2 families. We found that replicate samples correlated well with each other (r2=0.9-0.98). In 12/15 cases, the matched formalin-fixed and frozen samples predicted the same tumor molecular subtypes with confidence. These results demonstrate that the whole genome DASL assay is a valuable tool to profile degraded RNA from archival FFPE material. This assay will enable transcriptomic analysis of a large number of archival samples that are stored in pathology archives around the globe and consequently will have the potential to improve our understanding and characterisation of many diseases.
2010-06-09 | GSE21921 | GEO
Project description:Advantages of RNA-Seq over array based platforms are quantitative gene expression and discovery of expressed single nucleotide variants (eSNVs) and fusion transcripts from a single platform, but the sensitivity for each of these characteristics is unknown. We measured gene expression in a set of manually degraded RNAs, nine pairs of matched fresh-frozen, and FFPE RNA isolated from breast tumor with the hybridization based, NanoString nCounter, (226 gene panel) and with whole transcriptome RNA-Seq using RiboZeroGold ScriptSeq V2 library preparation kits. We performed correlation analyses of gene expression between samples and across platforms. We then specifically assessed whole transcriptome expression of lincRNA and discovery of eSNVs and fusion transcripts in the FFPE RNA-Seq data. For gene expression in the manually degraded samples, we observed Pearson correlation of >0.94 and >0.80 with NanoString and ScriptSeq protocols respectively. Gene expression data for matched fresh-frozen and FFPE samples yielded mean Pearson correlations of 0.874 and 0.783 for NanoString (226 genes) and ScriptSeq whole transcriptome protocols respectively. Specifically for lincRNAs, we observed superb Pearson correlation (0.988) between matched fresh-frozen and FFPE pairs. FFPE samples across NanoString and RNA-Seq platforms gave a mean Pearson correlation of 0.838. In FFPE libraries, we detected 53.4% of high confidence SNVs and 24% of high confidence fusion transcripts. Sensitivity of fusion transcript detection was not overcome by an increase in depth of sequencing up to 3-fold (increase from ~56 to ~159 million reads). Both NanoString and ScriptSeq RNA-Seq technologies yield reliable gene expression data for degraded and FFPE material. The high degree of correlation between NanoString and RNA-Seq platforms suggests discovery based whole transciptome studies from FFPE material will produce reliable expression data. The RiboZeroGold ScriptSeq protocol performed particularly well for lincRNA expression from FFPE libraries but detection of eSNV and fusion transcripts was less sensitive. We performed RNASeq on RNA from nine matched pairs of fresh-frozen and FFPE tissues from breast cancer patients. The goal was to test the RiboZeroGold ScriptSeq complete low input library preparation kit for degraded RNA samples.
2013-12-06 | E-GEOD-51124 | biostudies-arrayexpress
Project description:Clinical exome sequencing of cells freshly isolated from 12 human colorectal carcinoma patients (tumor endothelial cells, normal colon endothelial cells, PBMCs, each n=12) in comparison to DNA isolated from microdissected tumor cells (n=11) from corresponding FFPE-tissue blocks
2023-05-01 | E-MTAB-10521 | biostudies-arrayexpress
Project description:A major challenge to the study of tumor DNA copy number (CN) in clinical specimens is the lack of appropriate fresh frozen samples and thus a dependence on Formalin-Fixed Paraffin Embedded (FFPE) banked samples, which typically have more extensive clinical follow up information. However, on most high density CN platforms, DNA from FFPE tissues generally underperforms or suffers high failure rates compared to fresh frozen samples because of DNA degradation and cross-linking. Molecular Inversion Probe (MIP) technology has been applied successfully to obtain high quality CN and genotype data from DNA isolated from cell lines and frozen tumor samples. Since the MIP probes require only a small (~40 bp) target binding site, we reasoned they may be well suited to assess FFPE samples. In this study, we successfully applied MIP technology with a panel of 50,000 markers to CN determination in FFPE samples. Using an input of 37 ng genomic DNA, we demonstrated high quali ty CN data with MIP technology from 93 FFPE samples from seven diverse collections. We found that the performance of FFPE DNA for CN determination was comparable to that of DNA obtained from matched frozen tumor, with only a modest loss in performance of DNA
2009-02-18 | GSE14743 | GEO