Browse
Submit Data
Databases
API
Help

Dataset Information

5 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

FFPE samples from cavitational ultrasonic surgical aspirates are suitable for RNA profiling of gliomas.

ABSTRACT: During surgical procedures for gliomas, tissue material obtained from cavitational ultrasonic surgical aspirators (CUSAs) is generally discarded but can actually exceed the amount and quality of certain tumour core resections (TCRs). Despite reports indicating the suitability of CUSA-derived material for diagnosis and research, its use is still marginal. We extended these conclusions to formalin-fixed, paraffin-embedded (FFPE) samples, the most common format for archival tumour tissue in anatomical pathology departments, by conducting for the first time RNA-seq analysis in CUSA aspirates. We compared the molecular diagnosis of somatic mutations used in the clinical routine and the gene expression profiles of fixed solid material from CUSA aspirates and TCRs from the same patients in selected gliomas encompassing grades II to IV. Despite the characteristic heterogeneity of gliomas, we found substantial similarities between the corresponding aspirates and TCRs that included transcriptional signatures associated with glioma subtypes. Based on these results, we confirmed that CUSA-fixed biomaterials from glioma surgeries are appropriate for downstream applications and biomarkers screening.

SUBMITTER: Alenda C

PROVIDER: S-EPMC8297856 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

FFPE-samples from cavitational ultrasonic surgical aspirates are suitable for RNA profiling of gliomas

Project description:During surgical procedures of gliomas, tissular material obtained from cavitational ultrasonic surgical aspirators (CUSAs) is generally discarded but can exceed amount and quality of certain tumour core resections (TCRs). From archived FFPE-samples, we compared the profiles of somatic mutations and gene expression in the solid material from aspirates and TCRs obtained from the same patients in selected gliomas encompassing grade II to IV. Despite the characteristic heterogeneity of gliomas, we found substantial similarities between the corresponding aspirates and TCRs that included mutations used in the clinical routine and glioma-associated transcriptional signatures. Based on these results, we confirmed the suitability of CUSA-fixed biomaterial from glioma surgeries for downstream applications.

2021-10-20 | GSE166696 | GEO

FFPE-samples from cavitational ultrasonic surgical aspirates are suitable for RNA profiling of gliomas

Project description:FFPE-samples from cavitational ultrasonic surgical aspirates are suitable for RNA profiling of gliomas

| PRJNA701629 | ENA

Gene expression profiling of FFPE breast cancer samples

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

Optimization for Sequencing and Analysis of Degraded FFPE-RNA Samples.

Project description:Gene expression analysis by RNA sequencing (RNA-seq) enables unique insights into clinical samples that can potentially lead to mechanistic understanding of the basis of various diseases as well as resistance and/or susceptibility mechanisms. However, FFPE tissues, which represent the most common method for preserving tissue morphology in clinical specimens, are not the best sources for gene expression profiling analysis. The RNA obtained from such samples is often degraded, fragmented, and chemically modified, which leads to suboptimal sequencing libraries. In turn, these generate poor quality sequence data that may not be reliable for gene expression analysis and mutation discovery. In order to make the most of FFPE samples and obtain the best possible data from low quality samples, it is important to take certain precautions while planning experimental design, preparing sequencing libraries, and during data analysis. This includes the use of appropriate metrics for precise sample quality control (QC), identifying the best methods for various steps during the sequencing library generation, and careful library QC. In addition, applying correct software tools and parameters for sequence data analysis is critical in order to identify artifacts in RNA-seq data, filter out contamination and low quality reads, assess uniformity of gene coverage, and measure the reproducibility of gene expression profiles among biological replicates. These steps can ensure high accuracy and reproducibility for profiling of very heterogeneous RNA samples. Here we describe the various steps for sample QC, library preparation and QC, sequencing, and data analysis that can help to increase the amount of useful data obtained from low quality RNA, such as that obtained from FFPE-RNA tissues.

| S-EPMC8815082 | biostudies-literature

Gene expression profiling of FFPE breast cancer samples [Affymetrix platform]

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

Quantitative Expression Profiling of RNA from Formalin-Fixed, Paraffin-Embedded (FFPE)and Fresh Frozen (FF) Breast Cancer samples

Project description:Unluckily, FFPE archival methods lead to partial RNA degradation, limiting the amount of derivable information. This study aims to evaluate if the DASL gene expression assay, designed to generate reproducible data from degraded RNAs, is a reliable method to apply on RNA from FFPE tissues. In order to do that, we analyzed 20 FFPE breast cancer samples and 20 FF (Fresh Frozen) matched samples with the Illumina Whole Genome DASL platform for a genome-wide expression profiling.

| S-ECPF-TABM-1081 | biostudies-other

Robust detection of immune transcripts in FFPE samples using targeted RNA sequencing.

Project description:Current criteria for identifying cancer patients suitable for immunotherapy with immune checkpoint blockers (ICBs) are subjective and prone to misinterpretation, as they mainly rely on the visual assessment of CD274 (best known as PD-L1) expression levels by immunohistochemistry (IHC). To address this issue, we developed a RNA sequencing (RNAseq)-based approach that specifically measures the abundance of immune transcripts in formalin-fixed paraffin embedded (FFPE) specimens. Besides exhibiting superior sensitivity as compared to whole transcriptome RNAseq, our assay requires little starting material, implying that it is compatible with RNA degradation normally caused by formalin. Here, we demonstrate that a targeted RNAseq panel reliably profiles mRNA expression levels in FFPE samples from a cohort of ovarian carcinoma patients. The expression profile of immune transcripts as measured by targeted RNAseq in FFPE versus freshly frozen (FF) samples from the same tumor was highly concordant, in spite of the RNA quality issues associated with formalin fixation. Moreover, the results of targeted RNAseq on FFPE specimens exhibited a robust correlation with mRNA expression levels as measured on the same samples by quantitative RT-PCR, as well as with protein abundance as determined by IHC. These findings demonstrate that RNAseq profiling on archival FFPE tissues can be used reliably in studies assessing the efficacy of cancer immunotherapy.

| S-EPMC5356875 | biostudies-literature

Gene expression profiling of FFPE breast cancer samples [Illumina DASL WG platform]

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

RNA-seq from archival FFPE breast cancer samples: molecular pathway fidelity and novel discovery.

Project description:BackgroundFormalin-fixed, paraffin-embedded (FFPE) tissues for RNA-seq have advantages over fresh frozen tissue including abundance and availability, connection to rich clinical data, and association with patient outcomes. However, FFPE-derived RNA is highly degraded and chemically modified, which impacts its utility as a faithful source for biological inquiry.MethodsTrue archival FFPE breast cancer cases (n = 58), stored at room temperature for 2-23 years, were utilized to identify key steps in tissue selection, RNA isolation, and library choice. Gene expression fidelity was evaluated by comparing FFPE data to public data obtained from fresh tissues, and by employing single-gene, gene set and transcription network-based regulon analyses.ResultsWe report a single 10 μm section of breast tissue yields sufficient RNA for RNA-seq, and a relationship between RNA quality and block age that was not linear. We find single-gene analysis is limiting with FFPE tissues, while targeted gene set approaches effectively distinguish ER+ from ER- breast cancers. Novel utilization of regulon analysis identified the transcription factor KDM4B to associate with ER+ disease, with KDM4B regulon activity and gene expression having prognostic significance in an independent cohort of ER+ cases.ConclusionOur results, which outline a robust FFPE-RNA-seq pipeline for broad use, support utilizing FFPE tissues to address key questions in the breast cancer field, including the delineation between indolent and life-threatening disease, biological stratification and molecular mechanisms of treatment resistance.

| S-EPMC6924022 | biostudies-literature

Exon-array profiling of squamous cell carcinoma and adenocarcinoma in human cervical FFPE samples

Project description:Degradation and chemical modification of RNA in formalin-fixed paraffin-embedded (FFPE) samples hamper their use in expression profiling studies. In this study, we investigated the feasibility of gene expression signature generation from archival FFPE materials. Nineteen cervical squamous cell carcinoma (SCC) and nine adenocarcinoma (AC) 10~16-year-old FFPE samples were profiled using Affymetrix Exon 1.0 ST arrays. A comparison of the global gene expression changes between SCC and AC revealed 1217 differentially expressed genes. Of these, 1062 showed significantly higher expression levels in SCC relative to AC, and 155 genes were found to be specifically upregulated in AC. When the 1217-gene signature was tested on a fresh-frozen human non-small cell lung cancer (NSCLC) series, it correctly separated the 58 NSCLC samples into SCC and AC. In conclusion, our results showed that clinically and biologically relevant gene expression profiles can be derived from FFPE samples with Exon array profiling. The study population contains 28 FFPE human cervix samples (19 SCC and 9 AC). Histopathology assessment and p63 IHC were performed on all samples to confirm their histological subtypes. Total RNA was extracted and hybridised to Affymetrix Human Exon 1.0 ST arrays. Expression values were normalised using RMA. Only exonic probesets that were flagged as present (DABG< 0.01) in at least three samples were retained for further analysis. LIMMA was used to identify probesets that were differentially expressed between SCC and AC subtypes, using FDR ≤ 0.01 and absolute fold-change ≥ 2 as cutoff.

| S-ECPF-GEOD-27388 | biostudies-other

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data