Direct measurement of RNA Polymerase II hypertranscription in cancer FFPE samples
Ontology highlight
ABSTRACT: Hypertranscription occurs at targets of oncogene transcription factors in aggressive human cancers. However, detection relies on mRNAs which are heavily processed and have variable half-lives, and on accurate cell number estimations. Here we apply FFPE-CUTAC on slides and curls to quantify hypertranscription at regulatory elements and replication-coupled histone genes.
Project description:Hypertranscription facilitates biosynthetically demanding cellular state transitions through global upregulation of the nascent transcriptome. Despite its potential widespread relevance, documented examples of hypertranscription remain few and limited predominantly to early development. This limitation is in large part due to the fact that modern sequencing approaches, including single-cell RNA sequencing (scRNA-seq), generally assume similar levels of transcriptional output per cell. Here, we use molecule counting and spike-in normalization to develop absolute scaling of single-cell RNA sequencing data. Absolute scaling enables an estimation of total transcript abundances per cell, which we validate in embryonic stem cell (ESC) and germline data and apply to adult mouse organs at steady-state or during regeneration.
Project description:The study aimed to apply 95GC, originally developed using fresh‑frozen (FF) tissues, to formalin‑fixed paraffin‑embedded (FFPE) tissues, because FFPE tissues are routinely prepared and are readily available. Although we previously reported the applicability of 72GC to FFPE tissues (DOI: 10.1016/j.clbc.2013.11.006), the present study aimed to improve the accuracy of 95GC for FFPE tissues using the reference robust multiarray average (refRMA) method, optimized for FFPE tissues. Therefore, a 95GC RS (Recurrence Score) was first developed and then the accuracy of the newly developed 95GC algorithm for FFPE tissues was evaluated using the 95GC RS. These 14 pairs of FF and FFPE data are included in the concordance analysis of 95GC high/low results between FF and FFPE (Figure 3B). J05 was created in a form more suited to the actual clinical setting, such as leaving the postoperative samples for 4 hours before immersing them in formalin. A long time passed, and now it is unclear how these 14 cases were distributed among the analysis. *Note: This old data has been updated multiple times by the other members. Then, there are some differences from the original paper and unclear points still remain. Therefore, do not use it for formal analysis aimed at public insurance coverage etc. This is for research purposes only. Please cite this paper when writing a new paper. PMID: 31638234 DOI: 10.3892/or.2019.7358
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.
Project description:Formalin fixation and paraffin-embedding (FFPE) is the most common method to preserve human tissue for clinical diagnosis and FFPE archives represent an invaluable resource for biomedical research. Proteins in FFPE material are stable over decades but their efficient extraction and streamlined analysis by mass spectrometry (MS)-based proteomics has so far proven challenging. Here, we describe an MS-based proteomic workflow for quantitative profiling of large FFPE tissue cohorts directly from pathology glass slides. We demonstrate broad applicability of the workflow to clinical pathology specimens and variable sample amounts, including low-input cancer tissue isolated by laser microdissection. Using state-of-the-art data dependent acquisition (DDA) and data independent (DIA) MS workflows, we consistently quantify a large part of the proteome in 100 min single-run analyses. In an adenoma cohort comprising more than 100 samples, total work up took less than a day. We observed a moderate trend towards lower protein identifications in long-term stored samples (>15 years) but clustering into distinct proteomic subtypes was independent of archival time. Our results underline the great promise of FFPE tissues for patient phenotyping using unbiased proteomics and prove the feasibility of analyzing large tissue cohorts in a robust, timely and streamlined manner.
Project description:The Hippo pathway controls the activity of YAP/TAZ transcriptional coactivators through a kinase cascade. Despite the critical role of this pathway in tissue growth and tumorigenesis, it is not fully understood how YAP/TAZ–mediated transcription drives proliferation. By analyzing the effects of inactivating LATS1/2 kinases, the direct upstream inhibitors of YAP/TAZ, on mouse brain development and applying cell-number–normalized transcriptome analysis, we discovered that YAP/TAZ activation causes a global increase in transcription activity, known as hypertranscription, and upregulates many genes associated with increased biosynthetic capacity and proliferation. In contrast, conventional read-depth–normalized RNA-sequencing analysis failed to detect the scope of the transcriptome shift and missed most relevant gene ontologies. Hypertranscription in neural progenitors inhibits differentiation and triggers DNA replication stress, DNA damage, and p53 activation, resulting in massive apoptosis. Our findings reveal the remarkable impact of YAP/TAZ activation on global transcription activity and have important implications for understanding YAP/TAZ function
Project description:We present FFPE-ATAC, a new ATAC-seq tool for chromatin accessibility profiling that decodes the chromatin accessibility from mouse FFPE tissue and clinical archived FFPE tissues. The FFPE-ATAC generates the high-quality chromatin accessibility profiles from clinical FFPE tissue sections with 5-20 µm thickness, and reveals the disease-associated regulatory elements in different types of FFPE archived tissue. FFPE-ATAC enables to decode the chromatin states regulating the gene regulation in the cancer and understand the epigenetic regulation in the translational studies.
Project description:The Hippo pathway controls the activity of YAP/TAZ transcriptional coactivators through a kinase cascade. Despite the critical role of this pathway in tissue growth and tumorigenesis, it is not fully understood how YAP/TAZ–mediated transcription drives proliferation. By analyzing the effects of inactivating LATS1/2 kinases, the direct upstream inhibitors of YAP/TAZ, on mouse brain development and applying cell-number–normalized transcriptome analysis, we discovered that YAP/TAZ activation causes a global increase in transcription activity, known as hypertranscription, and upregulates many genes associated with increased biosynthetic capacity and proliferation. In contrast, conventional read-depth–normalized RNA-sequencing analysis failed to detect the scope of the transcriptome shift and missed most relevant gene ontologies. Hypertranscription in neural progenitors inhibits differentiation and triggers DNA replication stress, DNA damage, and p53 activation, resulting in massive apoptosis. Our findings reveal the remarkable impact of YAP/TAZ activation on global transcription activity and have important implications for understanding YAP/TAZ function.