scholarly journals CRISPR-Cas9 genome editing in human cells works via the Fanconi Anemia pathway

2017 ◽  
Author(s):  
Chris D Richardson ◽  
Katelynn R Kazane ◽  
Sharon J Feng ◽  
Nicholas L Bray ◽  
Axel J Schäfer ◽  
...  
Keyword(s):  
Dna Repair ◽  
Genome Editing ◽  
Fanconi Anemia ◽  
High Efficiency ◽  
Genetic Diseases ◽  
Dermal Fibroblasts ◽  
Human Cells ◽  
Individual Gene ◽  
Break Site ◽  
Repair Pathways

AbstractCRISPR-Cas9 genome editing creates targeted double strand breaks (DSBs) in eukaryotic cells that are processed by cellular DNA repair pathways. Co-administration of single stranded oligonucleotide donor DNA (ssODN) during editing can result in high-efficiency (>20%) incorporation of ssODN sequences into the break site. This process is commonly referred to as homology directed repair (HDR) and here referred to as single stranded template repair (SSTR) to distinguish it from repair using a double stranded DNA donor (dsDonor). The high efficacy of SSTR makes it a promising avenue for the treatment of genetic diseases1,2, but the genetic basis of SSTR editing is still unclear, leaving its use a mostly empiric process. To determine the pathways underlying SSTR in human cells, we developed a coupled knockdown-editing screening system capable of interrogating multiple editing outcomes in the context of thousands of individual gene knockdowns. Unexpectedly, we found that SSTR requires multiple components of the Fanconi Anemia (FA) repair pathway, but does not require Rad51-mediated homologous recombination, distinguishing SSTR from repair using dsDonors. Knockdown of FA genes impacts SSTR without altering break repair by non-homologous end joining (NHEJ) in multiple human cell lines and in neonatal dermal fibroblasts. Our results establish an unanticipated and central role for the FA pathway in templated repair from single stranded DNA by human cells. Therapeutic genome editing has been proposed to treat genetic disorders caused by deficiencies in DNA repair, including Fanconi Anemia. Our data imply that patient genotype and/or transcriptome profoundly impact the effectiveness of gene editing treatments and that adjuvant treatments to bias cells towards FA repair pathways could have considerable therapeutic value.

scholarly journals Tissue Specific DNA Repair Outcomes Shape the Landscape of Genome Editing

2021 ◽  
Vol 12 ◽  
Author(s):  
Mathilde Meyenberg ◽  
Joana Ferreira da Silva ◽  
Joanna I. Loizou
Keyword(s):  
Dna Repair ◽  
Genome Editing ◽  
Genetic Diseases ◽  
Dna Double Strand Breaks ◽  
Dna Breaks ◽  
Dna Damage And Repair ◽  
Tissue Specific ◽  
Precise Control ◽  
Repair Processes ◽  
Recent Developments

The use of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas9 has moved from bench to bedside in less than 10years, realising the vision of correcting disease through genome editing. The accuracy and safety of this approach relies on the precise control of DNA damage and repair processes to achieve the desired editing outcomes. Strategies for modulating pathway choice for repairing CRISPR-mediated DNA double-strand breaks (DSBs) have advanced the genome editing field. However, the promise of correcting genetic diseases with CRISPR-Cas9 based therapies is restrained by a lack of insight into controlling desired editing outcomes in cells of different tissue origin. Here, we review recent developments and urge for a greater understanding of tissue specific DNA repair processes of CRISPR-induced DNA breaks. We propose that integrated mapping of tissue specific DNA repair processes will fundamentally empower the implementation of precise and safe genome editing therapies for a larger variety of diseases.

scholarly journals BRCA1 and S phase DNA repair pathways restrict LINE-1 retrotransposition in human cells

2020 ◽  
Vol 27 (2) ◽  
pp. 179-191 ◽  
Author(s):  
Paolo Mita ◽  
Xiaoji Sun ◽  
David Fenyö ◽  
David J. Kahler ◽  
Donghui Li ◽  
...  
Keyword(s):  
Dna Repair ◽  
S Phase ◽  
Human Cells ◽  
Repair Pathways

scholarly journals Highly efficient and specific genome editing in human cells with paired CRISPR-Cas9 nickase ribonucleoproteins

2019 ◽  
Author(s):  
Jacob Lamberth ◽  
Laura Daley ◽  
Pachai Natarajan ◽  
Stanislav Khoruzhenko ◽  
Nurit Becker ◽  
...  
Keyword(s):  
Cell Culture ◽  
Genome Editing ◽  
Plasmid Dna ◽  
High Efficiency ◽  
High Specificity ◽  
Human Cells ◽  
Dna And Rna ◽  
Genome Modification ◽  
Delivery Technology ◽  
Target Effects

ABSTRACTCRISPR technology has opened up many diverse genome editing possibilities in human somatic cells, but has been limited in the therapeutic realm by both potential off-target effects and low genome modification efficiencies. Recent advancements to combat these limitations include delivering Cas9 nucleases directly to cells as highly purified ribonucleoproteins (RNPs) instead of the conventional plasmid DNA and RNA-based approaches. Here, we extend RNP-based delivery in cell culture to a less characterized CRISPR format which implements paired Cas9 nickases. The use of paired nickase Cas9 RNP system, combined with a GMP-compliant non-viral delivery technology, enables editing in human cells with high specificity and high efficiency, a development that opens up the technology for further exploration into a more therapeutic role.

Functional interaction between Fanconi anemia and mTOR pathways during stalled replication fork recovery

2020 ◽  
Author(s):  
Matthew Nolan ◽  
Kenneth Knudson ◽  
Marina K Holz ◽  
Indrajit Chaudhury
Keyword(s):  
Dna Repair ◽  
Dna Replication ◽  
Fanconi Anemia ◽  
Replication Fork ◽  
Genomic Stability ◽  
Repair Pathway ◽  
Functional Interaction ◽  
Mechanistic Target Of Rapamycin ◽  
Dna Strands ◽  
Repair Pathways

We have previously demonstrated that Fanconi Anemia (FA) proteins work in concert with other FA and non-FA proteins to mediate stalled replication fork restart. Previous studies suggest a connection between FA protein FANCD2 and a non-FA protein mechanistic target of rapamycin (mTOR). A recent study showed that mTOR is involved in actin-dependent DNA replication fork restart, suggesting possible roles in FA DNA repair pathway. In this study, we demonstrate that during replication stress mTOR interacts and cooperates with FANCD2 to provide cellular stability, mediates stalled replication fork restart and prevents nucleolytic degradation of the nascent DNA strands. Taken together, this study unravels a novel functional cross-talk between two important mechanisms: mTOR and FA DNA repair pathways that ensure genomic stability.

scholarly journals Preserving genome integrity in human cells via DNA double-strand break repair

2020 ◽  
Vol 31 (9) ◽  
pp. 859-865 ◽  
Author(s):  
Ryan B. Jensen ◽  
Eli Rothenberg
Keyword(s):  
Dna Repair ◽  
Strand Break ◽  
Double Strand Break ◽  
Human Cells ◽  
Cell Cycle Checkpoints ◽  
Human Diseases ◽  
Genome Integrity ◽  
Dsb Repair ◽  
Dna Double Strand Break ◽  
Repair Pathways

The efficient maintenance of genome integrity in the face of cellular stress is vital to protect against human diseases such as cancer. DNA replication, chromatin dynamics, cellular signaling, nuclear architecture, cell cycle checkpoints, and other cellular activities contribute to the delicate spatiotemporal control that cells utilize to regulate and maintain genome stability. This perspective will highlight DNA double-strand break (DSB) repair pathways in human cells, how DNA repair failures can lead to human disease, and how PARP inhibitors have emerged as a novel clinical therapy to treat homologous recombination-deficient tumors. We briefly discuss how failures in DNA repair produce a permissive genetic environment in which preneoplastic cells evolve to reach their full tumorigenic potential. Finally, we conclude that an in-depth understanding of DNA DSB repair pathways in human cells will lead to novel therapeutic strategies to treat cancer and potentially other human diseases.

CRISPR–Cas9 genome editing in human cells occurs via the Fanconi anemia pathway

2018 ◽  
Vol 50 (8) ◽  
pp. 1132-1139 ◽  
Author(s):  
Chris D. Richardson ◽  
Katelynn R. Kazane ◽  
Sharon J. Feng ◽  
Elena Zelin ◽  
Nicholas L. Bray ◽  
...  
Keyword(s):  
Genome Editing ◽  
Fanconi Anemia ◽  
Human Cells ◽  
Fanconi Anemia Pathway

scholarly journals BRCA1 Mediated Homologous Recombination and S Phase DNA Repair Pathways Restrict LINE-1 Retrotransposition in Human Cells

2019 ◽  
Author(s):  
Xiaoji Sun ◽  
Paolo Mita ◽  
David J. Kahler ◽  
Donghui Li ◽  
Aleksandra Wudzinska ◽  
...  
Keyword(s):  
Dna Repair ◽  
Homologous Recombination ◽  
Potential Role ◽  
Genome Instability ◽  
Protein Translation ◽  
Human Cells ◽  
Host Factors ◽  
Factors Affecting ◽  
A Genome ◽  
Repair Pathways

AbstractLong interspersed element-1 (LINE-1 or L1) is the only autonomous retrotransposon active in human cells. L1s DNA makes about 17% of the human genome and retrotransposition of a few active L1 copies has been detected in various tumors, underscoring the potential role of L1 in mediating or increasing genome instability during tumorigenic development. Different host factors have been shown to influence L1 mobility through several mechanisms. However, systematic analyses of host factors affecting L1 retrotransposition are limited. Here, we developed a high-throughput microscopy-based retrotransposition assay and coupled it to a genome-wide siRNA knockdown screen to study the cellular regulators of L1 retrotransposition in human cells. We showed that L1 insertion frequency was stimulated by knockdown of Double-Stranded Break (DSB) repair factors that are active in the S/G2 phase of the cell cycle including Homologous Recombination (HR), Fanconi Anemia (FA) and, to a less extent, microhomology-mediated end-joining (MMEJ) factors. In particular, we show that BRCA1, an E3 ubiquitin ligase with a key role in several DNA repair pathways, plays multiple roles in regulating L1; BRCA1 knockdown directly affects L1 retrotransposition frequency and structure and also plays a role in controlling L1 ORF2 protein translation through L1 mRNA binding. These results suggest the existence of a “battle” between HR factors and L1 retrotransposons, revealing a potential role for L1 in development of tumors characterized by BRCA1 and HR repair deficiencies.

scholarly journals Approaches to Enhance Precise CRISPR/Cas9-Mediated Genome Editing

2021 ◽  
Vol 22 (16) ◽  
pp. 8571
Author(s):  
Christopher E. Denes ◽  
Alexander J. Cole ◽  
Yagiz Alp Aksoy ◽  
Geng Li ◽  
G. Gregory Neely ◽  
...  
Keyword(s):  
Dna Repair ◽  
Genome Editing ◽  
Nuclear Dna ◽  
Great Promise ◽  
End Joining ◽  
Strand Breaks ◽  
Homology Directed Repair ◽  
Repair Pathways ◽  
Non Homologous End Joining ◽  
Small Molecule Modulators

Modification of the human genome has immense potential for preventing or treating disease. Modern genome editing techniques based on CRISPR/Cas9 show great promise for altering disease-relevant genes. The efficacy of precision editing at CRISPR/Cas9-induced double-strand breaks is dependent on the relative activities of nuclear DNA repair pathways, including the homology-directed repair and error-prone non-homologous end-joining pathways. The competition between multiple DNA repair pathways generates mosaic and/or therapeutically undesirable editing outcomes. Importantly, genetic models have validated key DNA repair pathways as druggable targets for increasing editing efficacy. In this review, we highlight approaches that can be used to achieve the desired genome modification, including the latest progress using small molecule modulators and engineered CRISPR/Cas proteins to enhance precision editing.

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