Nieuwenhuis, E. E. S. | Search bioRxiv

bioRxiv2021

Mutation-specific reporter for the optimization and enrichment of prime editing

We present a fluorescent prime editing and enrichment reporter (fluoPEER), which can be tailored to any genomic target site. This system rapidly and faithfully ranks the efficiency of prime edit guide RNAs (pegRNAs) and any prime editor protein, including novel variants with flexible PAM recognition. Successful reporter editing enriches for genomic editing. FluoPEER can be employed for efficient correction of patient cells and to elucidate cellular mechanisms needed for successful prime editing.

molecular biology↗

bioRxiv2020

Prime editing for functional repair in patient-derived disease models

Prime editing is a novel genome editing technology using fusion proteins of Cas9-nickase and reverse transcriptase, that holds promise to correct the vast majority of genetic defects. We develop prime editing for primary adult stem cells grown in organoid culture models. First, we generate precise in-frame deletions in the gene encoding {beta}-catenin (CTNNB1) that result in proliferation independent of Wnt-stimuli, mimicking a mechanism of the development of liver cancer. Moreover, prime editing functionally recovers diseasecausing mutations in intestinal organoids from patients with DGAT1-deficiency and liver organoids from a patient with Wilson disease (ATP7B). Prime editing is as efficient in 3D grown organoids as in 2D grown cell lines and offers greater precision than Cas9-mediated homology directed repair (HDR). Base editing remains more reliable than prime editing but is restricted to a subgroup of pathogenic mutations. Whole-genome sequencing of four prime-edited clonal organoid lines reveals absence of genome-wide off-target effects underscoring therapeutic potential of this versatile and precise gene editing strategy.

genomics↗