Controlling DNA Repair

Caribou Biosciences, Inc. has announced that members of its scientific team have discovered that DNA repair outcomes following Cas9 cleavage of DNA are non-random and follow highly reproducible patterns for each target site. The ability to control DNA repair outcomes has significant implications for the use of CRISPR-Cas9 in product development.

The study is published in the current edition of Molecular Cell and entitled DNA Repair Profiling Reveals Non-random Outcomes at Cas9-Mediated Breaks. As discussed therein, Caribou researchers cut 223 sites in the human genome with Cas9 and analyzed the DNA repair profiles at each site. They discovered that the DNA repair outcomes, namely the collection of insertions and deletions that are produced by the cellular repair machinery following DNA cutting, generate reproducible patterns at each target site. The research also demonstrated how these non-random outcomes can be harnessed to produce a desired effect, such as a gene knockout or the reading frame restoration of a disease-causing allele.

“This discovery represents a fundamental advance in the development of CRISPR-Cas9 technology. Through careful measurement of the outcomes of the DNA repair machinery, we can understand the specific patterns of editing that occur within a cell population with a high degree of certainty,” said Andrew May, D.Phil., Chief Scientific Officer of Caribou. “Caribou is at the forefront of cutting-edge research in genome engineering, and I am delighted that our world class scientific team continues to make significant contributions to develop the potential of CRISPR-Cas9 gene editing technology.” 

The findings of this study have potential applications across a range of industries. For example, these findings can accelerate the progress of gene-editing research because DNA repair profiling in one cell type may accurately predict repair outcomes in other cell types, including human primary cells. This can allow scientists to conduct research in standard, easy-to-use cell lines that can then be applied to more challenging cell types. Future studies are expected to explore these patterns of predictability outside of human cells and with a range of enzymes, with potential relevance to fields such as agriculture, industrial biotechnology and beyond.