Imaging flow cytometry-based cellular screening elucidates pathophysiology in individuals with Variants of Uncertain Significance
Muffels IJJ, Waterham HR, D'Alessandro G, Zagnoli-Vieira G, Sacher M, Lefeber DJ, Van der Vinne C, Roifman CM, Gassen KLI, Rehmann H, Van Haaften-Visser DY, Nieuwenhuis ESS, Jackson SP, Fuchs SA, Wijk F, van Hasselt P.
Genome Medicine 17(1):12.
Background: Deciphering variants of uncertain significance (VUS) represents a major diagnostic challenge, partially due to the lack of easy-to-use and versatile cellular readouts that aid the interpretation of pathogenicity and pathophysiology. To address this challenge, we propose a high-throughput screening of cellular functionality through an imaging flow cytometry (IFC)-based platform.
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Under the microscope: DNA damage tracked through cell generations
Reilly EL and Aitken SJ
Nature 642(8068):576-577
Instability of the genome is a hallmark of cancer that can arise when damaged DNA is carried across cell divisions, fuelling both small- and large-scale genetic variation in cells. Writing in Nature, Panagopoulos et al. present a multimodal platform that tracks single cells to uncover how DNA damage propagates unevenly through cell lineages. The authors’ approach reveals the origin and extent of differences in the traits and genomic stability of individual cells in each of the daughter and granddaughter generations produced from successive cell divisions.
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Comprehensive interrogation of synthetic lethality in the DNA damage response
Fielden J, Siegner SM, Gallagher DN, Schröder MS, Dello Stritto MR, Lam S, Kobel L, Schlapansky MF, Jackson SP, Cejka P, Jost M, Corn JE.
Nature 640(8060):1093-1102
The DNA damage response (DDR) is a multifaceted network of pathways that preserves genome stability. Unravelling the complementary interplay between these pathways remains a challenge. Here we used CRISPR interference (CRISPRi) screening to comprehensively map the genetic interactions required for survival during normal human cell homeostasis across all core DDR genes. We captured known interactions and discovered myriad new connections that are available online.
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KLF5 loss sensitizes cells to ATR inhibition and is synthetic lethal with ARID1A deficiency
Awwad SW, Doyle C, Coulthard J, Bader AS, Gueorguieva N, Lam S, Gupta V, Belotserkovskaya R, Tran TA, Balasubramanian S, Jackson SP.
Nature Communications 16(1):480
ATR plays key roles in cellular responses to DNA damage and replication stress, a pervasive feature of cancer cells. ATR inhibitors (ATRi) are in clinical development for treating various cancers, including those with high replication stress, such as is elicited by ARID1A deficiency, but the cellular mechanisms that determine ATRi efficacy in such backgrounds are unclear. Here, we have conducted unbiased genome-scale CRISPR screens in ARID1A-deficient and proficient cells treated with ATRi.
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TDP1 splice-site mutation causes HAP1 cell hypersensitivity to topoisomerase I inhibition
Gang Goh C, Bader AS, Tran T-A, Belotserkovskaya R, D’Alessandro G and Jackson SP.
Nucleic Acids Research, gkae1163
HAP1 is a near-haploid human cell line commonly used for mutagenesis and genome editing studies due to its hemizygous nature. We noticed an unusual hypersensitivity of HAP1 to camptothecin, an antineoplastic drug that stabilizes topoisomerase I cleavage complexes (TOP1ccs). We have attributed this hypersensitivity to a deficiency of TDP1, a key phosphodiesterase involved in resolving abortive TOP1ccs.
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Transcription-coupled repair of DNA-protein crosslinks
Carnie CJ, Jackson SP and Stingele J.
Trends in Cell Biology 35(4), 316-329
DNA–protein crosslinks (DPCs) are highly toxic DNA lesions that are relevant to multiple human diseases. They are caused by various endogenous and environmental agents, and from the actions of enzymes such as topoisomerases. DPCs impede DNA polymerases, triggering replication-coupled DPC repair. Until recently the consequences of DPC blockade of RNA polymerases remained unclear. New methodologies for studying DPC repair have enabled the discovery of a transcription-coupled (TC) DPC repair pathway.
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Genome-aware annotation of CRISPR guides validates targets in variant cell lines and enhances discovery in screens
Lam S, Thomas JC and Jackson SP.
Genome Medicine 16:139 (2024)
Background CRISPR-Cas9 technology has revolutionised genetic screens and can inform on gene essentiality and chemo-genetic interactions. It is easily deployed and widely supported with many pooled CRISPR libraries available commercially. However, discrepancies between the reference genomes used in the design of those CRISPR libraries and the cell line under investigation can lead to loss of signal or introduction of bias. The problem is particularly acute when dealing with variant cell lines such as cancer cell lines.
Results Here, we present an algorithm, EXOme-guided Re-annotation of nuCleotIde SEquences (Exorcise), which uses sequence search to detect and correct mis-annotations in CRISPR libraries.
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The eEF2 kinase coordinates the DNA damage response to cisplatin by supporting p53 activation
Lim JKM, Samiei A, Delaidelli A, de Santis JO, Brinkmann V, Carnie CJ, Radiloff D, Hruby L, Kahler A, Cran J, Leprivier G, Sorensen PH.
Cell Death & Disease 15(7):501.
Eukaryotic elongation factor 2 (eEF2) kinase (eEF2K) is a stress-responsive hub that inhibits the translation elongation factor eEF2, and consequently mRNA translation elongation, in response to hypoxia and nutrient deprivation. EEF2K is also involved in the response to DNA damage but its role in response to DNA crosslinks, as induced by cisplatin, is not known. Here we found that eEF2K is critical to mediate the cellular response to cisplatin.
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