Similar Datasets
Project description:Pooled genetic screening with CRISPR/Cas9 has enabled genome-wide high-resolution assignment of genes to phenotypes. To assess the effect of a given genetic perturbation, each sgRNA must be evaluated in hundreds of cells to overcome stochastic genetic drift and obtain robust results. In complex models that display particularly high heterogeneity, such as organoids or tumors transplanted into mice however, sufficient representation typically requires unreasonable scaling, thus preventing genome-wide screens at high resolution. Here we present CRISPR-StAR, a screening paradigm that overcomes intrinsic and extrinsic heterogeneity as well as genetic drift in bottlenecks by leveraging internal controls generated through activating sgRNAs only in half of the progenies of each cell. We use CRISPR-StAR to reveal in vivo-specific genetic dependencies in a genome-wide screen in mouse melanoma. Benchmarking to a conventional screening setup highlights the improved data quality this technology delivers. We anticipate CRISPR-StAR to set a new standard for genetic screening in complex models, foremost in vivo.
2024-11-05 | GSE262308 | GEO
Project description:Pooled genetic screening with CRISPR/Cas9 has enabled genome-wide high-resolution assignment of genes to phenotypes. To assess the effect of a given genetic perturbation, each sgRNA must be evaluated in hundreds of cells to overcome stochastic genetic drift and obtain robust results. In complex models that display particularly high heterogeneity, such as organoids or tumors transplanted into mice however, sufficient representation typically requires unreasonable scaling, thus preventing genome-wide screens at high resolution. Here we present CRISPR-StAR, a screening paradigm that overcomes intrinsic and extrinsic heterogeneity as well as genetic drift in bottlenecks by leveraging internal controls generated through activating sgRNAs only in half of the progenies of each cell. We use CRISPR-StAR to reveal in vivo-specific genetic dependencies in a genome-wide screen in mouse melanoma. Benchmarking to a conventional screening setup highlights the improved data quality this technology delivers. We anticipate CRISPR-StAR to set a new standard for genetic screening in complex models, foremost in vivo.
2024-11-05 | GSE262307 | GEO
Project description:CRISPR-StAR, a paradigm leveraging internal controls, empowers genetic screening in vivo
| PRJNA1091311 | ENA
Project description:CRISPR-StAR, a paradigm leveraging internal controls, empowers genetic screening in vivo (batch 1)
| PRJNA1091313 | ENA
Project description:CRISPR-StAR, a paradigm leveraging internal controls, empowers genetic screening in vivo (batch 2)
| PRJNA1091314 | ENA
Project description:MotivationTranscriptome-based computational drug repurposing has attracted considerable interest by bringing about faster and more cost-effective drug discovery. Nevertheless, key limitations of the current drug connectivity-mapping paradigm have been long overlooked, including the lack of effective means to determine optimal query gene signatures.ResultsThe novel approach Dr Insight implements a frame-breaking statistical model for the 'hand-shake' between disease and drug data. The genome-wide screening of concordantly expressed genes (CEGs) eliminates the need for subjective selection of query signatures, added to eliciting better proxy for potential disease-specific drug targets. Extensive comparisons on simulated and real cancer datasets have validated the superior performance of Dr Insight over several popular drug-repurposing methods to detect known cancer drugs and drug-target interactions. A proof-of-concept trial using the TCGA breast cancer dataset demonstrates the application of Dr Insight for a comprehensive analysis, from redirection of drug therapies, to a systematic construction of disease-specific drug-target networks.Availability and implementationDr Insight R package is available at https://cran.r-project.org/web/packages/DrInsight/index.html.Supplementary informationSupplementary data are available at Bioinformatics online.
| S-EPMC6691331 | biostudies-literature
Project description:Identifying genes involved in biological processes is critical for understanding the molecular building blocks of life. We used engineered CRISPR (clustered regularly interspaced short palindromic repeats) to efficiently mutate specific loci in zebrafish (Danio rerio) and screen for genes involved in vertebrate biological processes. We found that increasing CRISPR efficiency by injecting optimized amounts of Cas9-encoding mRNA and multiplexing single guide RNAs (sgRNAs) allowed for phenocopy of known mutants across many phenotypes in embryos. We performed a proof-of-concept screen in which we used intersecting, multiplexed pool injections to examine 48 loci and identified two new genes involved in electrical-synapse formation. By deep sequencing target loci, we found that 90% of the genes were effectively screened. We conclude that CRISPR can be used as a powerful reverse genetic screening strategy in vivo in a vertebrate system.
| S-EPMC4667794 | biostudies-literature
Project description:PurposeFetal fraction (FF) is the percent of cell-free DNA (cfDNA) in the mother's peripheral blood that is of fetal origin, which plays a pivotal role in noninvasive prenatal screening (NIPS). We present a method that can reliably estimate FFs by examining autosome single-nucleotide polymorphisms (SNPs).MethodsEven at a very low sequencing depth, there are plenty of SNPs covered by more than one read. At those SNPs, we define read heterozygosity and demonstrate that the percent of read heterozygosity is a function of FF, which allows FF to be inferred.ResultsWe first demonstrated the effectiveness of our method in inferring FF. Then we used the inferred FF as an informative alternative prior to computing Bayes factors to test for aneuploidy, and observed better power than the Z-test. In analysis of clinical samples, we were able to identify female-male twins thanks to the accurate FF inference.ConclusionKnowing FF improves efficacy of NIPS. It brings a powerful Bayesian method, allows "no call" for samples with small FFs, renders screening for XXY syndrome simpler, and permits an adaptive design to sequence at a higher depth for samples with small FFs.
| S-EPMC7000331 | biostudies-literature
Project description:To identify essential gene responding to anti-PD-1 immunotherapy, we performed in vivo Genome-scale CRISPR-Cas9 knockout screening. We found that cohesin complex invovled in regulation of anti-PD-1 immunotherapy.
2022-01-14 | GSE125201 | GEO
Project description:Immunotherapy with PD-1 checkpoint blockade is effective in only a minority of patients with cancer, suggesting that additional treatment strategies are needed. Here we use a pooled in vivo genetic screening approach using CRISPR-Cas9 genome editing in transplantable tumours in mice treated with immunotherapy to discover previously undescribed immunotherapy targets. We tested 2,368 genes expressed by melanoma cells to identify those that synergize with or cause resistance to checkpoint blockade. We recovered the known immune evasion molecules PD-L1 and CD47, and confirmed that defects in interferon-? signalling caused resistance to immunotherapy. Tumours were sensitized to immunotherapy by deletion of genes involved in several diverse pathways, including NF-?B signalling, antigen presentation and the unfolded protein response. In addition, deletion of the protein tyrosine phosphatase PTPN2 in tumour cells increased the efficacy of immunotherapy by enhancing interferon-?-mediated effects on antigen presentation and growth suppression. In vivo genetic screens in tumour models can identify new immunotherapy targets in unanticipated pathways.
| S-EPMC5924693 | biostudies-literature