Gene expression profiling of FFPE breast cancer samples [Affymetrix vs. Illumina]
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE51452 | GEO | 2015/02/25
SECONDARY ACCESSION(S): PRJNA223223
REPOSITORIES: GEO
Similar Datasets
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2015-02-25 | E-GEOD-51452 | biostudies-arrayexpress
Project description:The use of Affymetrix U133 2.0 Plus chips on FFPE samples when coupled with a qPCR-based sample pre-assessment step, yielded satisfactory results from the point of view of biological reliability. When compared with the Illumina DASL WG platform, specifically designed for degraded RNA, the data generated with the Affymetrix platform showed a wider interquartile range (IQR 1.32 vs 0.57, p<2.2x10-16) suggesting a superior discriminatory power within samples as indicated by the good agreement with the immunohistiochemically derived ER status. FFPE primary breast cancer samples profiled using Affymetrix HG-U133 Plus 2.0 microarray platform after RNA amplification with the Nugen WT-Ovation FFPE System The following criteria were considered for a direct comparison of 12 GEPs obtained from Affymetrix and DASL platforms: gene variability as defined by IQR, ESR1 expression in ER status subgroups defined by IHC, distribution of fold changes for predefined ER related genes when comparing ER positive and negative samples.
| S-ECPF-GEOD-51450 | biostudies-other
Project description:The use of Affymetrix U133 2.0 Plus chips on FFPE samples when coupled with a qPCR-based sample pre-assessment step, yielded satisfactory results from the point of view of biological reliability. When compared with the Illumina DASL WG platform, specifically designed for degraded RNA, the data generated with the Affymetrix platform showed a wider interquartile range (1.32 vs 0.57, p<2.2x10-16) suggesting a superior discriminatory power within samples as indicated by the good agreement with the immunohistiochemically derived ER status. FFPE primary breast cancer samples profiled using Illumina DASL WG platform after RNA amplification with the Nugen WT-Ovation FFPE System The following criteria were considered for a direct comparison of 12 GEPs obtained from Affymetrix and DASL platforms: gene variability as defined by IQR, ESR1 expression in ER status subgroups defined by IHC, distribution of fold changes for predefined ER related genes when comparing ER positive and negative samples.
| S-ECPF-GEOD-51451 | biostudies-other
Project description:We implemented an optimized processing, using alternative Chip Description Files (CDFs) and fRMA normalization, which improve the quality of downstream analysis. We profiled 44 FFPE primary breast cancer samples using Affymetrix HG-U133 Plus 2.0 microarray platform after RNA amplification with the Nugen WT-Ovation FFPE System
| S-ECPF-GEOD-38554 | biostudies-other
Project description:The use of Affymetrix U133 2.0 Plus chips on FFPE samples when coupled with a qPCR-based sample pre-assessment step, yielded satisfactory results from the point of view of biological reliability. When compared with the Illumina DASL WG platform, specifically designed for degraded RNA, the data generated with the Affymetrix platform showed a wider interquartile range (IQR 1.32 vs 0.57, p<2.2x10-16) suggesting a superior discriminatory power within samples as indicated by the good agreement with the immunohistiochemically derived ER status.
2015-02-25 | GSE51450 | GEO
Project description:The use of Affymetrix U133 2.0 Plus chips on FFPE samples when coupled with a qPCR-based sample pre-assessment step, yielded satisfactory results from the point of view of biological reliability. When compared with the Illumina DASL WG platform, specifically designed for degraded RNA, the data generated with the Affymetrix platform showed a wider interquartile range (1.32 vs 0.57, p<2.2x10-16) suggesting a superior discriminatory power within samples as indicated by the good agreement with the immunohistiochemically derived ER status. FFPE primary breast cancer samples profiled using Illumina DASL WG platform after RNA amplification with the Nugen WT-Ovation FFPE System
2015-02-25 | GSE51451 | GEO
Project description:The use of Affymetrix U133 2.0 Plus chips on FFPE samples when coupled with a qPCR-based sample pre-assessment step, yielded satisfactory results from the point of view of biological reliability. When compared with the Illumina DASL WG platform, specifically designed for degraded RNA, the data generated with the Affymetrix platform showed a wider interquartile range (IQR 1.32 vs 0.57, p<2.2x10-16) suggesting a superior discriminatory power within samples as indicated by the good agreement with the immunohistiochemically derived ER status. FFPE primary breast cancer samples profiled using Affymetrix HG-U133 Plus 2.0 microarray platform after RNA amplification with the Nugen WT-Ovation FFPE System The following criteria were considered for a direct comparison of 12 GEPs obtained from Affymetrix and DASL platforms: gene variability as defined by IQR, ESR1 expression in ER status subgroups defined by IHC, distribution of fold changes for predefined ER related genes when comparing ER positive and negative samples.
2015-02-25 | E-GEOD-51450 | biostudies-arrayexpress
Project description:Formalin fixed paraffin-embedded (FFPE) tumor specimens are the conventionally archived material in clinical practice, representing an invaluable tissue source for biomarkers development, validation and routine implementation. For many prospective clinical trials, this material has been collected allowing for a prospective-retrospective study design which represents a successful strategy to define clinical utility for candidate markers. Gene expression data can be obtained even from FFPE specimens with the broadly used Affymetrix HG-U133 Plus 2.0 microarray platform. Nevertheless, important major discrepancies remain in expression data obtained from FFPE compared to fresh-frozen samples, prompting the need for appropriate data processing which could help to obtain more consistent results in downstream analyses. In a publicly available dataset of matched frozen and FFPE expression data, the performances of different normalization methods and specifically designed Chip Description Files (CDFs) were compared. The use of an alternative CDFs together with fRMA normalization significantly improved frozen-FFPE sample correlations, frozen-FFPE probeset correlations and agreement of differential analysis between different tumor subtypes. The relevance of our optimized data processing was assessed and validated using two independent datasets. In this study we demonstrated that an appropriate data processing can significantly improve the reliability of gene expression data derived from FFPE tissues using the standard Affymetrix platform. Tools for the implementation of our data processing algorithm are made publicly available at http://www.biocut.unito.it/cdf-ffpe/.
| S-EPMC3906036 | biostudies-literature
Project description:Background:Personalised medicine is nowadays a major objective in oncology. Molecular characterization of tumours through NGS offers the possibility to find possible therapeutic targets in a time- and cost-effective way. However, the low quality and complexity of FFPE DNA samples bring a series of disadvantages for massive parallel sequencing techniques compared to high-quality DNA samples (from blood cells, cell cultures, etc.). Results:We performed several experiments to understand the behaviour of FFPE DNA samples during the construction of SureSelectQXT libraries. First, we designed a quality checkpoint for FFPE DNA samples based on the quantification of their amplification capability (qcPCR). We observed that FFPE DNA samples can be classified according to DIN value and qcPCR concentration into unusable, or low-quality (LQ) and good-quality (GQ) DNA. For GQ samples, we increased the amount of input DNA to 150 ng and the digestion time to 30 min, whereas for LQ samples, we used 50 ng of DNA as input but we decreased the digestion time to 1 min. In all cases, we increased the cycles of the pre-hyb PCR to 10 but decreased the cycles of the post-hyb PCR to 8. In addition, we confirmed that using half of the volume of reagents can be beneficial. Finally, in order to obtain better results, we designed a decision flow-chart to achieve a seeding concentration of 12-14 pM for MiSeq Reagent Kit v2. Conclusions:Our experiments allowed us to unveil the behaviour of low-quality FFPE DNA samples during the construction of SureSelectQXT libraries. Sequencing results showed that, using our modified SureSelectQXT protocol, the final percentage of usable reads for low-quality samples was increased more than three times allowing to reach median depth/million reads values of 76.35. This value is equivalent to ~?0.9 and ~?0.7 of the values obtained for good-quality FFPE and high-quality DNA respectively.
| S-EPMC6182866 | biostudies-literature
Project description:The prognosis of colorectal cancer (CRC) stage II and III patients remains a challenge due to the difficulties of finding robust biomarkers suitable for testing clinical samples. The majority of published gene signatures of CRC have been generated on fresh frozen colorectal tissues. Because collection of frozen tissue is not practical for routine surgical pathology practice, a clinical test that improves prognostic capabilities beyond standard pathological staging of colon cancer will need to be designed for formalin-fixed paraffin-embedded (FFPE) tissues. The NanoString nCounter® platform is a gene expression analysis tool developed for use with FFPE-derived samples. We designed a custom nCounter® codeset based on elements from multiple published fresh frozen tissue microarray-based prognostic gene signatures for colon cancer, and we used this platform to systematically compare gene expression data from FFPE with matched microarray array data from frozen tissues. Our results show moderate correlation of gene expression between two platforms and discovery of a small subset of genes as candidate biomarkers for colon cancer prognosis that are detectable and quantifiable in FFPE tissue sections.
| S-EPMC4866771 | biostudies-literature