Search-and-replace genome editing without double-strand breaks or donor DNA
Authors: Jessie R Davis
David R Liu
Christopher Wilson
Andrew V Anzalone
Peyton B Randolph
Aditya Raguram
Gregory A Newby
Jonathan M Levy
Alexander A Sousa
Luke W Koblan
Peter J Chen
Journal: Nature (2019)
Discipline: Multidisciplinary
Keywords: Genome editing; Prime editing; Genetic variants; Disease; Cas9 endonuclease
Affiliations: Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of Harvard and MIT, Cambridge, MA, USA., Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA., Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA., Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of Harvard and MIT, Cambridge, MA, USA. ., Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA. ., Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA. .

Abstract:  Most genetic variants that contribute to disease1 are challenging to correct efficiently and without excess byproducts2-5. Here we describe prime editing, a versatile and precise genome editing method that directly writes new genetic information into a specified DNA site using a catalytically impaired Cas9 endonuclease fused to an engineered reverse transcriptase, programmed with a prime editing guide RNA (pegRNA) that both specifies the target site and encodes the desired edit. We performed more than 175 edits in human cells, including targeted insertions, deletions, and all 12 types of point mutation, without requiring double-strand breaks or donor DNA templates. We used prime editing in human cells to correct, efficiently and with few byproducts, the primary genetic causes of sickle cell disease (requiring a transversion in HBB) and Tay-Sachs disease (requiring a deletion in HEXA); to install a protective transversion in PRNP; and to insert various tags and epitopes precisely into target loci. Four human cell lines and primary post-mitotic mouse cortical neurons support prime editing with varying efficiencies. Prime editing shows higher or similar efficiency and fewer byproducts than homology-directed repair, has complementary strengths and weaknesses compared to base editing, and induces much lower off-target editing than Cas9 nuclease at known Cas9 off-target sites. Prime editing substantially expands the scope and capabilities of genome editing, and in principle could correct up to 89% of known genetic variants associated with human diseases. 

Retracted: No

PubPeer comments:
 Some data in this paper looks remarkably similar to data in another paper from shared authors, i.e. Jixiang Zhang, Jia Song, Dandan Wu, Jing Wang, Weiguo Dong - Hesperetin induces the apoptosis of hepatocellular carcinoma cells via mitochondrial pathway mediated by the increased intracellular reactive oxygen species, ATP and calcium - Med Oncol (2015) 32:101 - DOI: 10.1007 s12032-015-0516-z - https: pubpeer.com publications DCBA7D8E0CA145AE306242DB05A667 In particular three microscopy panels in Figure 4 of this paper looked similar to panels in Figure 2 of the other paper. These were later replaced in a 2019 correction. Note that the duplications not only represented different cells (liver cancer cells vs. gastric cancer cells) but also different concentrations of Hereperetin treatments. https: imgur.com a qWPqeVy ![file] , 
 And here are the original Figures 6 (Dig Dis Sci) and 7 (Med Oncol) compared with each other. This error has also been corrected. I thank the authors for correcting this error. ![file] ,