Targeted DNA-seq of Human HepG2 cells following editing with CRISPR/Cas9 upon chromatin modulation with TSA and EZH2i
ABSTRACT: We sought to characterise how chromatin states affected CRISPR/Cas9 activity and the induced indel profiles. We used two different doses of Trichostatin and two different doses of a EZH2 inhibitor to modulate the chromatin state and then performed targeted DNA-seq of selected sgRNA target regions to identify the indels.
Project description:We performed a large-scale genome-wide characterisation of indels generated following editing with CRISPR/Cas9. We used pools of sgRNAs and performed targeted capture and sequencing of the edited regions in HepG2 cells.
Project description:ARID1A, an epigentic modifier, is often mutated in ovarian clear cell carcinoma (OCCC). In addition, EZH2 is frequently upregulated in OCCC. Inhibtion of EZH2 with an inhibitor (GSK126) selectively inhibits ARID1A-mutated cells. This study was designed to understand changes in gene expression profiles following EZH2 inhibition or ARID1A restoration. Chromatin remodelers such as ARID1A are frequently mutated in a broad array of cancers. However, targeted cancer therapy based on ARID1A mutation status has not been described. Intriguingly, ARID1A mutated cancers typically lack genomic instability, suggesting significant involvement of epigenetic mechanisms. Here we show that inhibition of the EZH2 methyltransferase acts in a synthetic lethal manner in ARID1A mutated cells. Remarkably, ARID1A mutation status correlated with response to EZH2 inhibitor. Genome-wide profiling revealed antagonistic roles of ARID1A and EZH2 in gene regulation. Further, we identified PIK3IP1 as a direct ARID1A/EZH2 target gene whose upregulation contributes to the observed synthetic lethality in the EZH2 inhibitor treated ARID1A mutated cells. Significantly, EZH2 inhibitor caused the regression of established ARID1A mutated tumors in vivo. Together, this data demonstrate a synthetic lethality between ARID1A mutation and EZH2 inhibition. They indicate that pharmacological inhibition of EZH2 represents a novel treatment strategy for ARID1A mutated cancers.
Project description:We sequenced polyA mRNA from OVCAR8-ADR-Cas9 cells in which one or two of 3 epigenetic regulators (BRD4, KDM4C, KDM6B) had been knocked out to examine how global gene expression was affected and evaluate potential synergistic effects at a molecular level. Gene expression data (RNA-Seq) in OVCAR8-ADR-Cas9 cells infected with control vector or vectors expressing gRNAs targeting one of 4 epigenetic regulators (BRD4, KDM4C, KDM6B) with biological replicates.
Project description:The functional relevance of many microRNAs in the context of tumor biology remains unclear. Using CRISPR-Cas9 technology, we performed a global loss-of-function screen to test the impact of individual microRNAs on the growth of FLT3-ITD positive leukemia cells. This approach identified both evolutionarily conserved and non-conserved human microRNAs that function to suppress or promote tumor cell growth, revealing that microRNAs are extensively integrated into the molecular networks that control tumor cell physiology. Our study describes a powerful genetic approach by which the function of individual microRNAs can be assessed on a global level, and its use will rapidly advance our understanding of how microRNAs contribute to human disease. Loss-of-function CRISPR-Cas9 screen identifies genes whose loss leads to increased or decreased FLT3-ITD+ cell growth over 23 day time-course
Project description:The transcriptomics changes induced in the human liver cell line HepG2 by low and high doses of acetaminophen and solvent controls after treatment for 4 time points (12h, 24h, 48h and 72h) The study investigated differential gene expression in HepG2 cell line mRNA following 12 to 72 hours of exposure to low and high doses of acetaminophen and solvent controls. Three biological replicates per compound/solvent.
Project description:Cord blood hematopoietic stem cells (CB-HSCs) are an outstanding source for transplantation approaches. However, the amount of cells per donor is limited and culture expansion of CB-HSCs is accompanied by a loss of engraftment potential. In order to analyze the molecular mechanisms leading to this impaired potential we profiled global and local epigenotypes during the expansion of human CB hematopoietic stem and progenitor cells (HPSCs). Human CB-derived CD34+ cells were cultured in serum-free medium together with SCF, TPO, FGF, with or without Igfbp2 and Angptl5 (STF/STFIA cocktails). As compared to the STF cocktail, the STFIA cocktail maintains in vivo repopulation capacity of cultured CD34+ cells. Upon expansion, CD34+ cells genome-wide remodel their epigenotype and depending on the cytokine cocktail, cells show different H3K4me3 and H3K27me3 levels. Expanding cells without Igfbp2 and Angptl5 leads to higher global H3K27me3 levels. ChIPseq analyses reveal a cytokine cocktail-dependent redistribution of H3K27me3 profiles. Inhibition of the PRC2 component EZH2 counteracts the culture-associated loss of NOD scid gamma (NSG) engraftment potential. Collectively, our data reveal chromatin dynamics that underlie the culture-associated loss of engraftment potential. We identify PRC2 component EZH2 as being involved in the loss of engraftment potential during the in vitro expansion of HPSCs. 6 samples were hybridized GeneChip Human Gene 1.0 ST Arrays (Affymetrix)