Similar Datasets
Project description:Fixed-Tissue ChIP-seq for H3K27Ac profiling (FiTAc-seq) is an epigenetic method for profiling active enhancers and promoters in FFPE tissues. We previously developed a modified ChIP-seq protocol (FiT-seq) for chromatin profiling in FFPE. FiT-seq produces high-quality chromatin profiles particularly for methylated histone marks but is not optimized for H3K27Ac profiling. FiTAc-seq is a modified protocol that replaces the proteinase K digestion applied in FiT-seq with extended heating at 65°C in more stringent detergent conditions and a minimized sonication step, to produce robust genome-wide H3K27Ac maps from clinical samples. We demonstrate FiTAc-seq suitability to generate high quality enhancer landscapes and SE annotation in a number of archived FFPE samples from distinct tumor types. This approach will be of great interest both for basic and clinical researchers. The entire protocol from FFPE blocks to sequence ready library can be accomplished within 4 days.
2020-06-26 | GSE140806 | GEO
Project description:Fixed-Tissue ChIP-seq for H3K27Ac profiling (FiTAc-seq) is an epigenetic method for profiling active enhancers and promoters in FFPE tissues. We previously developed a modified ChIP-seq protocol (FiT-seq) for chromatin profiling in FFPE. FiT-seq produces high-quality chromatin profiles particularly for methylated histone marks but is not optimized for H3K27Ac profiling. FiTAc-seq is a modified protocol that replaces the proteinase K digestion applied in FiT-seq with extended heating at 65°C in more stringent detergent conditions and a minimized sonication step, to produce robust genome-wide H3K27Ac maps from clinical samples. We demonstrate FiTAc-seq suitability to generate high quality enhancer landscapes and SE annotation in a number of archived FFPE samples from distinct tumor types. This approach will be of great interest both for basic and clinical researchers. The entire protocol from FFPE blocks to sequence ready library can be accomplished within 4 days.
2020-06-26 | GSE140805 | GEO
Project description:Fixed-Tissue ChIP-seq for H3K27Ac profiling (FiTAc-seq) is an epigenetic method for profiling active enhancers and promoters in FFPE tissues. We previously developed a modified ChIP-seq protocol (FiT-seq) for chromatin profiling in FFPE. FiT-seq produces high-quality chromatin profiles particularly for methylated histone marks but is not optimized for H3K27Ac profiling. FiTAc-seq is a modified protocol that replaces the proteinase K digestion applied in FiT-seq with extended heating at 65°C in more stringent detergent conditions and a minimized sonication step, to produce robust genome wide H3K27Ac maps from clinical samples. We demonstrate FiTAc-seq suitability to generate high quality enhancer landscapes and SE annotation in a number of archived FFPE samples from distinct tumor types. This approach will be of great interest both for basic and clinical researchers. The entire protocol from FFPE blocks to sequence ready library can be accomplished within 4 days.
2020-06-26 | GSE147446 | GEO
Project description:FiTAc-seq: Fixed-Tissue ChIP-seq for H3K27Ac profiling and super-enhancer analysis on FFPE tissues
| PRJNA590992 | ENA
Project description:FiTAc-seq: Fixed-Tissue ChIP-seq for H3K27Ac profiling and super-enhancer analysis on FFPE tissues [mouse]
| PRJNA590994 | ENA
Project description:FiTAc-seq: Fixed-Tissue ChIP-seq for H3K27Ac profiling and super-enhancer analysis on FFPE tissues [human]
| PRJNA590996 | ENA
Project description:FiTAc-seq: Fixed-Tissue ChIP-seq for H3K27Ac profiling and super-enhancer analysis on FFPE tissues [human PNET]
| PRJNA614651 | ENA
Project description:Accessible chromatin plays a central role in gene expression and chromatin architecture. Current accessible chromatin approaches depend on limited digestion/cutting and pasting adaptors at the accessible DNA, thus requiring additional materials and time for optimization. Universal NicE-seq (UniNicE-seq) is an improved accessible chromatin profiling method that negates the optimization step and is suited to a variety of mammalian cells and tissues. Addition of 5-methyldeoxycytidine triphosphate during accessible chromatin labeling and an on-bead library making step substantially improved the signal to noise ratio while protecting the accessible regions from repeated nicking in cell lines, mouse T cells, mouse kidney, and human frozen tissue sections. We also demonstrate one tube UniNicE-seq for the FFPE tissue section for direct NGS library preparation without sonication and DNA purification steps. These refinements allowed reliable mapping of accessible chromatin for high-resolution genomic feature studies.
| S-EPMC7507628 | biostudies-literature
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.
| S-EPMC5977534 | biostudies-literature
Project description:BackgroundArchived tissues from previously completed prospective trials represent invaluable resource for biomarker development. However, such specimens are often stored as sections on glass slides, in which RNA is severely degraded due to prolonged air exposure. We evaluated whether a proportion of archived sectioned formalin-fixed paraffin-embedded (AS-FFPE) tissues yield transcriptome profiles comparable to freshly cut (FC) FFPE tissues, which can be used for retrospective class prediction analysis.MethodsGenome-wide transcriptome profiles of 6 to 7-year-old AS-FFPE tissue sections (generated from 5 to 16-year-old blocks) of 83 hepatocellular carcinoma (HCC) and 47 liver cirrhosis samples were generated by using whole-genome DASL assay (Illumina) and digital transcript counting (nCounter) assay (NanoString), and gene signature-based prediction of HCC subclasses and prognosis was compared with previously generated FC-FFPE profiles from the same tissue blocks.ResultsRNA quality and assay reproducibility of AS-FFPE RNA were comparable to intermediate to poor quality FC-FFPE samples (RNA Integrity Number: up to 2.50, R-square for technical replicates: up to 0.93). Analyzable transcriptome profiles were obtained in 64 (77%) HCC and 36 (77%) cirrhosis samples. Statistically more confident predictions based on random resampling-based method (nearest template prediction) were obtained in 37 (58%) HCC and 13 (36%) cirrhosis samples. Predictions made in FC-FFPE profiles were reproduced in 36 (97%) HCC and 11 (85%) cirrhosis AS-FFPE profiles. nCounter assay was tested in 24 cirrhosis samples, which yielded confident prediction in 15 samples (63%), of which 10 samples (67%) showed concordant predictions with FC-FFPE profiles.ConclusionsAS-FFPE tissues yielded poorer quality RNA and transcriptome profiles compared to FC-FFPE tissues. Statistically more confident class prediction was feasible in 37 of 83 HCC samples and 13 of 47 cirrhosis samples. These results suggest that AS-FFPE tissues can be regarded as a resource for retrospective transcriptome-based class prediction analysis when they are the only available materials.
| S-EPMC3907407 | biostudies-literature