Homo sapiens
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ABSTRACT:
PROVIDER: PRJNA113021 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:MicroRNAs (miRNAs) are small non-coding RNAs that repress gene expression at the post transcriptional level via an antisense RNA-RNA interaction. Generally, miRNAs derived from snap frozen or fresh samples are used for array based profiling. Since tissues in most pathology departments are available only in formalin fixed and paraffin embedded state, we sought to evaluate the miRNA derived from formalin fixed and paraffin embedded (FFPE) samples for microarray analysis. In this study, miRNAs extracted from matched snap frozen and FFPE samples were profiled using the Agilent miRNA array platform. Each miRNA sample was hybridized to arrays containing probes interrogating 470 human miRNAs. A total of seven cases were compared in either duplicate or triplicate. Intrachip and interchip analyses demonstrated that the processes of miRNA extraction, labeling and hybridization from both frozen and FFPE samples are highly reproducible and add little variation to the results, as technical replicates showed high correlations (Kendall tau=0.722-0.853, Spearman rank correlation coefficient=0.891-0.954). Our results showed consistent high correlation between matched frozen and FFPE samples (Kendall tau=0.669-0.815, Spearman rank correlation coefficient=0.847-0.948), supporting the use of FFPE-derived miRNAs for profiling. Keywords: formalin-fixed and paraffin-embedded (FFPE) miRNA profiling
2008-11-01 | GSE12458 | GEO
Project description:A study to evaluate techniques for repairing DNA from formalin-fixed paraffin-embedded (FFPE) tissue samples by direct comparison of FFPE DNA repair methods prior to analysis on genome-wide methylation array to matched fresh frozen (FF) tissues.
2014-12-17 | GSE59038 | GEO
Project description:MicroRNA expression profiling in matched lesional skin samples from 25 patients with psoriasis using the miRNA analysis platform miRCURY LNATM MicroRNA array (v. 11.0) (Exiqon). Aim: To explore the effect of three different preservation methods (Formalin-fixation paraffin-embedding (FFPE), frozen (FS) and OCT-embedding (OCT)) on miRNA expression levels in matched lesional skin samples from 25 patients with psoriasis.
2012-03-22 | GSE28729 | GEO
Project description:MicroRNAs (miRNAs) are small non-coding RNAs that repress gene expression at the post transcriptional level via an antisense RNA-RNA interaction. Generally, miRNAs derived from snap frozen or fresh samples are used for array based profiling. Since tissues in most pathology departments are available only in formalin fixed and paraffin embedded state, we sought to evaluate the miRNA derived from formalin fixed and paraffin embedded (FFPE) samples for microarray analysis. In this study, miRNAs extracted from matched snap frozen and FFPE samples were profiled using the Agilent miRNA array platform. Each miRNA sample was hybridized to arrays containing probes interrogating 470 human miRNAs. A total of seven cases were compared in either duplicate or triplicate. Intrachip and interchip analyses demonstrated that the processes of miRNA extraction, labeling and hybridization from both frozen and FFPE samples are highly reproducible and add little variation to the results, as technical replicates showed high correlations (Kendall tau=0.722-0.853, Spearman rank correlation coefficient=0.891-0.954). Our results showed consistent high correlation between matched frozen and FFPE samples (Kendall tau=0.669-0.815, Spearman rank correlation coefficient=0.847-0.948), supporting the use of FFPE-derived miRNAs for profiling. Keywords: formalin-fixed and paraffin-embedded (FFPE) miRNA profiling 7 matched frozen and FFPE lymphoid hyperplasia tissues were profiled and compared. Triplicate arrays were performed for two pairs of hyperplasia samples and duplicate arrays for three pairs of hyperplasia samples.
2010-05-17 | E-GEOD-12458 | biostudies-arrayexpress
Project description:Tissue biopsies are most commonly archived in a paraffin block following tissue fixation with formaldehyde (FFPE) or as fresh frozen tissue (FFT). While both methods preserve biological samples, little is known about how they affect the quantifiable proteome. We performed a ‘bottom-up’ proteomic analysis (N=20) of short and long-term archived FFPE surgical samples of human meningiomas and compared them to matched FFT specimens. FFT facilitated identification of a slightly higher number of proteins compared with matched FFPE specimens (5735 vs 5670 proteins, respectively (p < 0.05), regardless of archival time. However, marked differences in the proteome composition were apparent between FFPE and FFT specimens. Twenty-three percent of FFPE-derived peptides and 8% of FFT-derived peptides contained at least one chemical modification. Methylation and formylation were most prominent in FFPE-derives peptides (36% and 17% of modified FFPE peptides, respectively) while, most of phosphorylation and iron modifications appeared in FFT-derived peptides (p<0.001). A mean 14% (2.9) of peptides identified in FFPE contained at least one modified Lysine residue. Importantly, larger proteins were significantly overrepresented in FFT specimens, while FFPE specimens were enriched with smaller proteins. This work cautions against comparing results of proteomic studies derived from different archival methods.
2024-02-12 | PXD032108 | Pride
Project description:The reliability of differential expression analysis on FFPE expression profiles from Affymetrix arrays is questionable, due to the wide range of percent-present values reported in studies which profiled FFPE samples on Affymetrix arrays. Moreover the validity of externally defined gene-modules in FFPE microarray expression profiles is unknown. Using eight breast cancer tumors with available frozen and FFPE samples, five sample-matched data sets were generated from different combination of Affymetrix arrays, amplification-and-labeling kit and sample preservation method. The reliability of differential expression analysis was investigated by developing de novo ER/HER2 pathway gene-modules from matched data sets and validating it on external data set using ROC analysis. Spearman's rank correlation coefficient of module scores between matched FFPE-frozen expression profiles was used to measure reliability of externally defined gene-modules in FFPE expression profiles. Independent of array/amplification-kit/sample preservation method used, de novo ER/HER2 gene-modules derived from all matching data sets showed similar prediction performance during independent validation (AUC range; ER: 0.92-0.95, HER2: 0.88-0.91), except for de novo HER2 gene-module derived from FFPE data set with 3'IVT kit (AUC: 0.67-0.72). Further not all gene-module based biological signals present in frozen expression profiles can be recovered from matching FFPE microarray expression profiles using the currently available FFPE specific sample preparation kits. The gene-module based biological signal extracted from FFPE RNA, using microarrays, may not be as reliable as that from their frozen counterpart, if the sample preparation protocol used with FFPE RNA failed to recover relevant genes involved in the biological signal.
2018-09-05 | GSE93336 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below. The reliability of differential expression analysis on FFPE expression profiles from Affymetrix arrays is questionable, due to the wide range of percent-present values reported in studies which profiled FFPE samples on Affymetrix arrays. Moreover the validity of externally defined gene-modules in FFPE microarray expression profiles is unknown. Using eight breast cancer tumors with available frozen and FFPE samples, five sample-matched data sets were generated from different combination of Affymetrix arrays, amplification-and-labeling kit and sample preservation method. The reliability of differential expression analysis was investigated by developing de novo ER/HER2 pathway gene-modules from matched data sets and validating it on external data set using ROC analysis. Spearman's rank correlation coefficient of module scores between matched FFPE-frozen expression profiles was used to measure reliability of externally defined gene-modules in FFPE expression profiles. Independent of array/amplification-kit/sample preservation method used, de novo ER/HER2 gene-modules derived from all matching data sets showed similar prediction performance during independent validation (AUC range; ER: 0.92-0.95, HER2: 0.88-0.91), except for de novo HER2 gene-module derived from FFPE data set with 3'IVT kit (AUC: 0.67-0.72). Further not all gene-module based biological signals present in frozen expression profiles can be recovered from matching FFPE microarray expression profiles using the currently available FFPE specific sample preparation kits. The gene-module based biological signal extracted from FFPE RNA, using microarrays, may not be as reliable as that from their frozen counterpart, if the sample preparation protocol used with FFPE RNA failed to recover relevant genes involved in the biological signal.
2018-09-05 | GSE93338 | GEO
Project description:The reliability of differential expression analysis on FFPE expression profiles from Affymetrix arrays is questionable, due to the wide range of percent-present values reported in studies which profiled FFPE samples on Affymetrix arrays. Moreover the validity of externally defined gene-modules in FFPE microarray expression profiles is unknown. Using eight breast cancer tumors with available frozen and FFPE samples, five sample-matched data sets were generated from different combination of Affymetrix arrays, amplification-and-labeling kit and sample preservation method. The reliability of differential expression analysis was investigated by developing de novo ER/HER2 pathway gene-modules from matched data sets and validating it on external data set using ROC analysis. Spearman's rank correlation coefficient of module scores between matched FFPE-frozen expression profiles was used to measure reliability of externally defined gene-modules in FFPE expression profiles. Independent of array/amplification-kit/sample preservation method used, de novo ER/HER2 gene-modules derived from all matching data sets showed similar prediction performance during independent validation (AUC range; ER: 0.92-0.95, HER2: 0.88-0.91), except for de novo HER2 gene-module derived from FFPE data set with 3'IVT kit (AUC: 0.67-0.72). Further not all gene-module based biological signals present in frozen expression profiles can be recovered from matching FFPE microarray expression profiles using the currently available FFPE specific sample preparation kits. The gene-module based biological signal extracted from FFPE RNA, using microarrays, may not be as reliable as that from their frozen counterpart, if the sample preparation protocol used with FFPE RNA failed to recover relevant genes involved in the biological signal.
2018-09-05 | GSE93335 | GEO
Project description:The reliability of differential expression analysis on FFPE expression profiles from Affymetrix arrays is questionable, due to the wide range of percent-present values reported in studies which profiled FFPE samples on Affymetrix arrays. Moreover the validity of externally defined gene-modules in FFPE microarray expression profiles is unknown. Using eight breast cancer tumors with available frozen and FFPE samples, five sample-matched data sets were generated from different combination of Affymetrix arrays, amplification-and-labeling kit and sample preservation method. The reliability of differential expression analysis was investigated by developing de novo ER/HER2 pathway gene-modules from matched data sets and validating it on external data set using ROC analysis. Spearman's rank correlation coefficient of module scores between matched FFPE-frozen expression profiles was used to measure reliability of externally defined gene-modules in FFPE expression profiles. Independent of array/amplification-kit/sample preservation method used, de novo ER/HER2 gene-modules derived from all matching data sets showed similar prediction performance during independent validation (AUC range; ER: 0.92-0.95, HER2: 0.88-0.91), except for de novo HER2 gene-module derived from FFPE data set with 3'IVT kit (AUC: 0.67-0.72). Further not all gene-module based biological signals present in frozen expression profiles can be recovered from matching FFPE microarray expression profiles using the currently available FFPE specific sample preparation kits. The gene-module based biological signal extracted from FFPE RNA, using microarrays, may not be as reliable as that from their frozen counterpart, if the sample preparation protocol used with FFPE RNA failed to recover relevant genes involved in the biological signal.
2018-09-05 | GSE93332 | GEO
Project description:The reliability of differential expression analysis on FFPE expression profiles from Affymetrix arrays is questionable, due to the wide range of percent-present values reported in studies which profiled FFPE samples on Affymetrix arrays. Moreover the validity of externally defined gene-modules in FFPE microarray expression profiles is unknown. Using eight breast cancer tumors with available frozen and FFPE samples, five sample-matched data sets were generated from different combination of Affymetrix arrays, amplification-and-labeling kit and sample preservation method. The reliability of differential expression analysis was investigated by developing de novo ER/HER2 pathway gene-modules from matched data sets and validating it on external data set using ROC analysis. Spearman's rank correlation coefficient of module scores between matched FFPE-frozen expression profiles was used to measure reliability of externally defined gene-modules in FFPE expression profiles. Independent of array/amplification-kit/sample preservation method used, de novo ER/HER2 gene-modules derived from all matching data sets showed similar prediction performance during independent validation (AUC range; ER: 0.92-0.95, HER2: 0.88-0.91), except for de novo HER2 gene-module derived from FFPE data set with 3'IVT kit (AUC: 0.67-0.72). Further not all gene-module based biological signals present in frozen expression profiles can be recovered from matching FFPE microarray expression profiles using the currently available FFPE specific sample preparation kits. The gene-module based biological signal extracted from FFPE RNA, using microarrays, may not be as reliable as that from their frozen counterpart, if the sample preparation protocol used with FFPE RNA failed to recover relevant genes involved in the biological signal.
2018-09-05 | GSE93337 | GEO