Testicular gene expression changes with loss of Topaz1
TOPAZ1, a germ cell specific factor, is essential for male meiotic progression.
Specimen part
View SamplesBase Editing has been touted the most intelligent and precise application of the CRISPR platform so far, merging the simplicity of RNA-guided nucleases with deaminases that allow for the programmable generation of single base substitutions - without introduction of double-strand breaks. Even though the two-component system has been expected to cause off-target substitutions, studies involving cytosine base editors (CBEs) showed that in most cases, relatively few single base off-targets could be detected on DNA. We introduce the concept of multi-dimensional off-targeting, presenting an extensive amount of RNA cytidines being edited by DNA base editors. Epitranscriptomic off-target effects affected different cell lines and were independent of the guide RNAs used, suggesting Cas9-independent activity of the cytidine deaminase rAPOBEC1 on single-stranded RNA. With the help of protein engineering, we developed CBE variants with massively reduced inadvertent mutation of RNA that preserve and enhance DNA base editing capabilities. Overall design: HEK293T and HepG2 cells were transfected with regular and modified pCAG-BE3-P2A-EGFP or control pCAG-nCas9(D10A)-UGI-NLS-P2A-EGFP or control pCAG-P2A-EGFP constructs with various gRNAs as described below. Cells were sorted for top 5% GFP or all GFP + cells based on FITC signal. RNA-seq was performed to measure transcriptional changes associated with different constructs and guides.
Transcriptome-wide off-target RNA editing induced by CRISPR-guided DNA base editors.
Cell line, Treatment, Subject
View SamplesBase Editing has been touted the most intelligent and precise application of the CRISPR platform so far, merging the simplicity of RNA-guided nucleases with deaminases that allow for the programmable generation of single base substitutions - without introduction of double-strand breaks. Even though the two-component system has been expected to cause off-target substitutions, studies involving cytosine base editors (CBEs) showed that in most cases, relatively few single base off-targets could be detected on DNA. We introduce the concept of multi-dimensional off-targeting, presenting an extensive amount of RNA cytidines being edited by DNA base editors. Epitranscriptomic off-target effects affected different cell lines and were independent of the guide RNAs used, suggesting Cas9-independent activity of the cytidine deaminase rAPOBEC1 on single-stranded RNA. With the help of protein engineering, we developed CBE variants with massively reduced inadvertent mutation of RNA that preserve and enhance DNA base editing capabilities. Overall design: HEK293T and HepG2 cells were transfected with pCAG-BE3-P2A-EGFP or control pCAG-nCas9(D10A)-UGI-NLS-P2A-EGFP or control pCAG-P2A-EGFP constructs with various gRNAs as described below. Cells were sorted for top 5% GFP or all GFP + cells based on FITC signal. RNA-seq was performed to measure transcriptional changes associated with different constructs and guides.
Transcriptome-wide off-target RNA editing induced by CRISPR-guided DNA base editors.
Cell line, Treatment, Subject
View SamplesBase Editing has been touted the most intelligent and precise application of the CRISPR platform so far, merging the simplicity of RNA-guided nucleases with deaminases that allow for the programmable generation of single base substitutions - without introduction of double-strand breaks. Even though the two-component system has been expected to cause off-target substitutions, studies involving cytosine base editors (CBEs) showed that in most cases, relatively few single base off-targets could be detected on DNA. We introduce the concept of multi-dimensional off-targeting, presenting an extensive amount of RNA cytidines being edited by DNA base editors. Epitranscriptomic off-target effects affected different cell lines and were independent of the guide RNAs used, suggesting Cas9-independent activity of the cytidine deaminase rAPOBEC1 on single-stranded RNA. With the help of protein engineering, we developed CBE variants with massively reduced inadvertent mutation of RNA that preserve and enhance DNA base editing capabilities. Overall design: HEK293T cells were transfected with pCAG-BE3-P2A-EGFP or variants thereof or control pCAG-nCas9(D10A)-UGI-NLS-P2A-EGFP or control pCAG-P2A-EGFP constructs with various gRNAs as described below. Cells were sorted for top 5% GFP or all GFP + cells based on FITC signal. RNA-seq was performed to measure transcriptional changes associated with different constructs and guides.
Transcriptome-wide off-target RNA editing induced by CRISPR-guided DNA base editors.
Cell line, Treatment, Subject
View SamplesBase Editing has been touted the most intelligent and precise application of the CRISPR platform so far, merging the simplicity of RNA-guided nucleases with deaminases that allow for the programmable generation of single base substitutions - without introduction of double-strand breaks. Even though the two-component system has been expected to cause off-target substitutions, studies involving cytosine base editors (CBEs) showed that in most cases, relatively few single base off-targets could be detected on DNA. We introduce the concept of multi-dimensional off-targeting, presenting an extensive amount of RNA cytidines being edited by DNA base editors. Epitranscriptomic off-target effects affected different cell lines and were independent of the guide RNAs used, suggesting Cas9-independent activity of the cytidine deaminase rAPOBEC1 on single-stranded RNA. With the help of protein engineering, we developed CBE variants with massively reduced inadvertent mutation of RNA that preserve and enhance DNA base editing capabilities. Overall design: HEK293T or HepG2 cells were transfected with P2A-EGFP. Cells were sorted for top 5% GFP based on FITC signal. RNA-seq was performed to measure transcriptional changes associated with different constructs.
Transcriptome-wide off-target RNA editing induced by CRISPR-guided DNA base editors.
Specimen part, Treatment, Subject
View SamplesMultiple gene expression studies have demonstrated that breast cancer biological diversity is associated with distinct transcriptional programs. Transcription factors, because of their unique ability to coordinate the expression of multiple genes, are speculated to play a role in generating phenotypic plasticity associated with cancer progression including acquired drug resistance. Combinatorial libraries of artificial zinc-finger transcription factors (ZF-TFs) provide a robust means for inducing and understanding various functional components of the cancer phenotype. Herein, we utilized combinatorial ZF-TF library technology to better understand how breast cancer cells acquire resistance to a fulvestrant, a clinically important anti-endocrine therapeutic agent. We isolated six ZF-TF library members capable of inducing stable, long-term anti-endocrine drug-resistance in two independent estrogen receptor positive breast cancer cell lines. Comparative gene expression profile analysis of the ZF-TF-transduced breast cancer cell lines revealed a 72-gene cluster that constituted a common signature for the fulvestrant-resistance phenotype. Pathway enrichment-analysis of gene expression data revealed that the ZF-TF-induced fulvestrant resistance is associated with an estrogen receptor negative-like gene set and four unique myb-regulated gene sets. Furthermore, we identified a set of genes strongly expressed in the ZF-TF-induced fulvestrant-resistant cells that was correlated with a lower probability of distant metastasis-free or death-from-relapse-free survival of breast cancer patients.
Induction of stable drug resistance in human breast cancer cells using a combinatorial zinc finger transcription factor library.
No sample metadata fields
View SamplesTesticular and ovarian gene expression changes with loss of DMXL2
Dual role of DMXL2 in olfactory information transmission and the first wave of spermatogenesis.
Specimen part
View SamplesThe mammalian genome contains thousands of loci that transcribe long noncoding RNAs (lncRNAs), some of which are known to play critical roles in diverse cellular processes through a variety of mechanisms. While some lncRNA loci encode RNAs that act non-locally (in trans), emerging evidence indicates that many lncRNA loci act locally (in cis) to regulate expression of nearby genes—for example, through functions of the lncRNA promoter, transcription, or transcript itself. Despite their potentially important roles, it remains challenging to identify functional lncRNA loci and distinguish among these and other mechanisms. To address these challenges, we developed a genome-scale CRISPR-Cas9 activation screen targeting more than 10,000 lncRNA transcriptional start sites (TSSs) to identify noncoding loci that influence a phenotype of interest. We found 11 novel lncRNA loci that, upon recruitment of an activator, each mediate BRAF inhibitor resistance in melanoma. Most candidate loci appear to regulate nearby genes. Detailed analysis of one candidate, termed EMICERI, revealed that its transcriptional activation results in dosage-dependent activation of four neighboring protein-coding genes, one of which confers the resistance phenotype. Our screening and characterization approach provides a CRISPR toolkit to systematically discover functions of noncoding loci and elucidate their diverse roles in gene regulation and cellular function. Overall design: RNA-seq on A375 cells overexpressing candidate lncRNA or protein-coding gene.
Genome-scale activation screen identifies a lncRNA locus regulating a gene neighbourhood.
Specimen part, Cell line, Subject
View SamplesRNA-seq and ATAC-seq data to understand how gene regulation and chromatin accessibility correlates with function enrichment in CRISPR screen for melanoma drug resistance
Genome-scale activation screen identifies a lncRNA locus regulating a gene neighbourhood.
No sample metadata fields
View SamplesBackground: During early embryonic development, one of the two X chromosomes in mammalian female cells is inactivated to compensate for a potential imbalance in transcript levels with male cells containing a single X chromosome. We use mouse female Embryonic Stem Cells (ESCs) with nonrandom XCI and polymorphic X chromosomes to study the dynamics of gene silencing over the inactive X chromosome (Xi) by high-resolution allele-specific RNA-Seq. Results: Induction of XCI by differentiation of female ESCs shows that genes proximal to the X-inactivation center (XIC) are silenced earlier than distal genes, while lowly expressed genes show faster XCI dynamics than highly expressed genes. The active X chromosome shows a minor but significant increase in gene activity during differentiation, resulting in complete dosage compensation in differentiated cell types. Genes escaping XCI show little or no silencing during early propagation of XCI. Using allele-specific RNA-Seq of Neural Progenitor Cells (NPCs) generated from the female ESCs, we identify three regions distal to the XIC that stably escape XCI during differentiation of the female ESCs, as well as during propagation of the NPCs. These regions coincide with Topologically Associated Domains (TADs) as determined in the undifferentiated female ESCs. Also the previously characterized human gene clusters escaping XCI correlate with TADs. Conclusions: Together, the dynamics of gene silencing observed over the Xi during XCI provide further insight in the formation and maintenance of the repressive Xi complex. The association of regions of escape with TADs, in mouse and human, suggests a regulatory role for TADs during propagation of XCI. Overall design: 19 RNA-Seq profiles of mouse ESCs, EpiSCs and NPCs, mostly from distant crosses to allow allele specific mapping. 1 HiC profile of an undifferentiated mouse female ESC line containing a Tsix mutation. Mainly focusing on X inactivation.
Dynamics of gene silencing during X inactivation using allele-specific RNA-seq.
No sample metadata fields
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