Gene expression analysis of lung cancer using long time stored formalin-fixed and paraffin embedded (FFPE) tissue
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE31735 | GEO | 2011/09/15
SECONDARY ACCESSION(S): PRJNA145431
REPOSITORIES: GEO
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Project description:This study was performed to evaluated RNA extraction and gene expression analysis of FFPE specimen stored for more than 20 years. Using long time stored FFPE material; large retrospective studies correlating molecular features with therapeutic response and clinical outcome, can be performed. Quantitative PCR (qPCR) was used to evaluate RNA extraction methods and to compare gene expression profiles of FFPE and fresh frozen (FF) tissue. Extracted RNA was subsequently subjected to microarray analysis and compared to qPCR data. The Ambion RecoverAll kit appears to be particularly suited for RNA extraction of long time stored FFPE tissues. Gene expression analysis using Affymetrix platform displayed a high degree of correlation for endogenous control genes comparing FF and FFPE tissues. We conclude that high quality gene expression signatures can be recognized using Affymetrix gene expression platform on FFPE tissue stored for more than 20 years. However, a general interpretation must be done with caution as different FFPE procedures have varying effects on RNA quality. Three RNA extraction methods from Roche (Basel, Switzerland), Ambion (Austin, TX, USA) and Qiagen (Hilden, Germany), designed for FFPE material was used. The methods were compared using qPCR. For the qPCR analysis, two different concentrations of input cDNA were used (20ng and 100ng) and 32 human endogenous control genes were examined. RNA from the Ambion FFPE kit was further analyzed by using microarray. Amplification of RNA prior to microarray analysis was performed using Nugen technologies (San Carlos, CA, USA). Nugen has developed amplification kits both for FFPE and FF materials: WT- ovation FFPE RNA amplification System V2 (Nugen FFPE), Ovation FF RNA Amplification System V2 (Nugen V2 FF) and Ovation FF Pico RNA Amplification System (Nugen PICO FF). The Nugen FFPE kit, designed for FFPE material was only used for FFPE tissue. The Nugen Pico FF kit, designed to target small amounts of FF RNA (>500 pg) and the Nugen V2 FF kit designed to target total FF RNA, were only used for FF tissue. Affymetrix standard amplification protocol (Affy FF) designed for FF RNA was also included as the standard method for amplification.
2011-09-14 | E-GEOD-31735 | biostudies-arrayexpress
Project description:This experiment contains the RNA-Seq samples only. Formalin-fixed, paraffin-embedded (FFPE) tissues are an invaluable resource for clinical research. However, nucleic acids extracted from FFPE tissues are fragmented and chemically modified making them challenging to use in molecular studies. We analysed 23 fresh-frozen (FF), 35 FFPE and 38 paired FF/FFPE specimens, representing six different human tissue types (bladder, prostate and colon carcinoma; liver and colon normal tissue; reactive tonsil) in order to examine the potential use of FFPE samples in next-generation sequencing (NGS) based retrospective and prospective clinical studies. Two methods for DNA and three methods for RNA extraction from FFPE tissues were compared and were found to affect nucleic acid quantity and quality. DNA and RNA from selected FFPE and paired FF/FFPE specimens were used for exome and transcriptome analysis. Preparations of DNA Exome-Seq libraries was more challenging (29.5 % success) than that of RNA-Seq libraries, presumably because of modifications to FFPE tissue-derived DNA. Libraries could still be prepared from RNA isolated from two-decade old FFPE tissues. Data were analysed using the CLC Bio Genomics Workbench and revealed systematic differences between FF and FFPE tissue-derived nucleic acid libraries. In spite of this, pairwise analysis of DNA Exome-Seq data showed concordance for 70-80 % of variants in FF and FFPE samples stored for fewer than three years. RNA-Seq data showed high correlation of expression profiles in FF/FFPE pairs (Pearson Correlations of 0.90 +/- 0.05), irrespective of storage time (up to 244 months) and tissue type. A common set of 1,494 genes was identified with expression profiles that were significantly different between paired FF and FFPE samples irrespective of tissue type. Our results are promising and suggest that NGS can be used to study FFPE specimens in both prospective and retrospective archive-based studies in which FF specimens are not available.
2014-09-04 | E-MTAB-2523 | biostudies-arrayexpress
Project description:Attempts to establish a tissue bank from autopsy samples have led to uncovering of the secrets of many diseases. Here, we examined the length of time that the RNA from postmortem tissues is available for microarray analysis and reported the gene expression profile for up- and down-regulated genes during the postmortem interval (PMI). We extracted RNA from fresh-frozen (FF) and formalin-fixed paraffin-embedded (FFPE) brains and livers of three different groups of mice: 1) mice immediately after death, 2) mice that were stored at room temperature for 3 h after death, and 3) mice that were stored at 4°C for 18 h after death, as this storage resembles the human autopsy process in Japan. Based on the microarray analysis, we selected genes that were altered by >1.3-fold or <0.77-fold and classified these genes using hierarchical cluster analysis following DAVID (database for annotation, visualization, and integrated discovery) gene ontology analysis. These studies revealed that cytoskeleton-related genes were enriched in the set of up-regulated genes, while serine protease inhibitors were enriched in the set of down-regulated genes. Interestingly, although the RNA quality was maintained, up-regulated genes were not validated by quantitative PCR, suggesting that these genes may become fragmented or modified by an unknown mechanism. We extracted RNA from fresh-frozen (FF) brains and livers from mice under three different conditions: 1) mice just after death as a control, 2) mice that were stored at room temperature for 3 h after death, and 3) mice that were stored at 4°C for 18 h after death to resemble the human autopsy process. We also created formalin-fixed paraffin-embedded (FFPE) tissue blocks at the same time using mouse organs obtained under the three conditions described above. We then purified RNA from the FFPE tissue blocks. Furthermore, we performed microarray analysis to examine changes in the gene expression profiles during the postmortem interval in FF samples and to compare ene expression profiles between FF and FFPE samples at three different postmortem times as described for the FF samples.
2016-05-13 | E-GEOD-78203 | biostudies-arrayexpress
Project description:Purpose: The goals of this study is to determine the best method of gene expression quantification (RNA-seq, Microarray, NanoString) and amplification kits adapted to low-input and/or low-quality RNA samples (FFPE samples) Methods: Mouse bladder cancer cell line (mouse bladder cancer cell line, BC57) and mouse normal mouse normal urothelium were fixed in formalin and embedded in paraffin (FFPE), andfesh frozen (FF) in liquid nitrogen. The total RNA of these 4 samples were tested by 3 technologies (NanoString, RNA-seq and Microarray) and the results were compared to its reference (high-quality and high-input RNA of mouse bladder cancer cell line and mouse normal mouse normal urothelium). For NanoString with low-input RNA samples, each sample was tested by NanoString quantification after amplification by SMARTer Stranded Total RNA-Seq Kit - Pico Input mammelian and Ovation SoLo NuGEN RNA-seq System, and NanoString based on PCR approach with three input quantities: 50pg, 250pg and 2ng of total RNA, except for NanoString quantification after amplification by SMARTer Stranded Total RNA-Seq Kit - Pico Input mammelian kit for which the minimum recommended quantity was 250pg of total RNA. NanoString direct quantification was also done for FF and FFPE samples at high amount (50ng of total RNA) and results obtained from FF samples were considered as the reference. To determine which is the method for NanoString technology, low-input and low-quality RNA samples, we performed NanoString control quality metrics, principal component analysis, and a differential analysis between the mouse bladder cancer cell lines and the mouse normal mouse normal urothelium for each input quantity, amplification method and method of sample preservation (FF or FFPE). Results: The NanoString based PCR based approach is recommended for quantification of gene expression of FFPE and FF samples from 250pg of total RNA. However, NanoString quantification after amplification by SMARTer Stranded Total RNA-Seq Kit - Pico Input mammelian and Ovation SoLo NuGEN RNA-seq System is not recommended for FF and FFPE from low-input samples.
2024-07-19 | GSE117670 | GEO
Project description:We assessed the feasibility and reliability of microarray studies using formalin-fixed paraffin-embedded (FFPE) tissue-derived RNA compared with transcriptome data from paired fresh-frozen (FF) material. We established a robust workflow to generate highly reproducible microarray datasets from only 2 ng RNA input. For prior quality assessment, inspection of Agilent Bioanalyzer electropherograms, calculation of RNA fragment size distribution (DV200) and routine qPCR for selected references genes were done.
2018-04-13 | GSE104562 | GEO
Project description:We assessed the feasibility and reliability of microarray studies using formalin-fixed paraffin-embedded (FFPE) tissue-derived RNA compared with transcriptome data from paired fresh-frozen (FF) material. We established a robust workflow to generate highly reproducible microarray datasets from only 2 ng RNA input. For prior quality assessment, inspection of Agilent Bioanalyzer electropherograms, calculation of RNA fragment size distribution (DV200) and routine qPCR for selected references genes were done.
2018-04-13 | GSE104561 | GEO
Project description:In order to determine the impact of HIV infection on the breast cancer microenvironment, we sequenced total RNA from formalin-fixed paraffin-embedded (FFPE) breast cancer samples of 10 women (4 HIV-positive: 6 HIV-negative) for studying the transcriptome and retrotranscriptome of those. We performed RNA extraction from samples stored for more than 5 years, cDNA library preparation, total RNA sequencing (RNA-seq) and differentially expressed genes between conditions were analyzed.
2020-10-08 | GSE149156 | GEO
Project description:Purpose: The goals of this study is to determine the best method of gene expression quantification (RNA-seq, Microarray, NanoString) and amplification kits adapted to low-input and/or low-quality RNA samples (FFPE samples) Methods: Mouse bladder cancer cell line (mouse bladder cancer cell line, BC57) and mouse normal mouse normal urothelium were fixed in formalin and embedded in paraffin (FFPE), andfesh frozen (FF) in liquid nitrogen. The total RNA of these 4 samples were tested in triplicate by 3 technologies (NanoString, RNA-seq and Microarray) and the results were compared to its reference (high-quality and high-input RNA of mouse bladder cancer cell line and mouse normal mouse normal urothelium). For RNA-sequencing, each sample was tested by two library contruction kits: SMARTer Stranded Total RNA-Seq Kit - Pico Input mammelian and Ovation SoLo NuGEN RNA-seq System with three input quantities: 50pg, 250pg and 2ng of total RNA, except for the SMARTer Stranded Total RNA-Seq Kit - Pico Input mammelian kit for which the minimum recommended quantity was 250pg of total RNA. RNA-seq based on poly(A) tail enrichment was considered as the reference and was done for the two FF samples at high amount (1µg of total RNA) . Results obtained with the two tested kits were compared to those based on poly(A) tail enrichment. To determine which is the best kit suitable for RNA-seq, low-input and low-quality RNA samples, we performed RNA-seq control quality metrics, principal component analysis, and a differential analysis between the mouse bladder cancer cell lines and the mouse normal mouse normal urothelium for each input quantity, library kit and method of sample preservation (FF or FFPE). Results: The Ovation SoLo NuGEN RNA-seq System library kit are recommended for quantification of gene expression of FFPE and FF samples at low-input (down to 50pg) whereas the SMARTer Stranded Total RNA-Seq Kit - Pico Input mammelian is only suitable for FF samples from 250pg of total RNA.
2024-07-19 | GSE117677 | GEO
Project description:Background: To date, few studies have systematically characterized microarray gene expression signal performance with degraded RNA from formalin-fixed paraffin-embedded (FFPE) specimens in comparison to intact RNA from unfixed fresh-frozen (FF) specimens. Methodology: RNA was extracted and isolated from paired tumor and normal samples from both FFPE and FF kidney, lung and colon tissue specimens. Microarray signal dynamics on both the raw probe and probeset level were evaluated. A contrast metric was developed to directly compare microarray signal derived from RNA extracted from matched FFPE and FF specimens. Gene-level summaries were then compared to determine the degree of overlap in expression profiles. Results: RNA extracted from FFPE material was more degraded and fragmented than FF, resulting in reduced dynamic range of expression signal. It was found that probe performance is not affected uniformly and declines sharply toward 5￢ﾀﾙ end of genes. The most significant differences in FFPE vs. FF signal were consistent across three tissue types and enriched with ribosomal genes. Significance: Our results show that archived FFPE samples can be used to profile for expression signatures and assess differential expression similar to unfixed tissue sources. This study provides guidelines for application of these methods in the discovery, validation, and clinical application of microarray expression profiling with FFPE material. 53 samples: 16 FF colon, 7 FFPE colon, 6 FF lung, 8 FFPE lung, 8 FF kidney, and 8 FFPE kidney specimens. Samples are paired tumor and normal tissue. 1-4 biological replicates.
2010-11-25 | E-GEOD-19249 | biostudies-arrayexpress
Project description:Background: The main bottleneck for genomic studies of tumors is the limited availability of fresh frozen (FF) samples collected from patients, coupled with comprehensive long-term clinical follow-up. This shortage could be alleviated by using existing large archives of routinely obtained and stored Formalin-Fixed Paraffin-Embedded (FFPE) tissues. However, since these samples are partially degraded, their RNA sequencing is technically challenging. Results: In an effort to establish a reliable and practical procedure, we compared three protocols for RNA sequencing using pairs of FF and FFPE samples, both taken from the same breast tumor. In contrast to previous studies, we compared the expression profiles obtained from the two matched sample types, using the same protocol for both. Three protocols were tested on low initial amounts of RNA, as little as 100 ng, to represent the possibly limited availability of clinical samples. For two of the three protocols tested, poly(A) selection (mRNA-seq) and ribosomal-depletion, the total gene expression profiles of matched FF and FFPE pairs were highly correlated. For both protocols, differential gene expression between two FFPE samples was in agreement with their matched FF samples. Notably, although expression levels of FFPE samples by mRNA-seq were mainly represented by the 3'-end of the transcript, they yielded very similar results to those obtained by ribosomal-depletion protocol, which produces uniform coverage across the transcript. Further, focusing on clinically relevant genes, we showed that the high correlation between expression levels persists at higher resolutions. Conclusions: Using the poly(A) protocol for FFPE exhibited, unexpectedly, similar efficiency to the ribosomal-depletion protocol, with the latter requiring much higher (2-3 fold) sequencing depth to compensate for the relative low fraction of reads mapped to the transcriptome. The results indicate that standard poly(A)-based RNA sequencing of archived FFPE samples is a reliable and cost-effective alternative for measuring mRNA-seq on FF samples. Expression profiling of FFPE samples by mRNA-seq can facilitate much needed extensive retrospective clinical genomic studies.
2018-05-03 | GSE113976 | GEO