CRISPR/Cas9 method can lead to unintended DNA mutations that can have negative effects. Recently, Japanese researchers have developed a new gene-editing technique that is as effective as CRISPR/Cas9, yet significantly reduces these unintended mutations. In a new study published in Nature Communications , researchers led by Osaka University have introduced a new technique called NICER, based on the creation of several small cuts in single DNA strands by an enzyme Cas 9 nickase. For their first experiments, the research team used human lymphoblastic cells with a known heterozygous mutation in a gene called TK1. When these cells were treated with nickase to induce a single cut in the TK1 region, TK1 activity was recovered at a low rate. However, when nickase induced multiple cuts in this region on both homologous chromosomes, the efficiency of gene correction was increased approximately seventeen-fold via activation of a cellular repair mechanism. Because the NICER method does not involve DNA double-strand breaks or the use of exogenous DNA, this technique appears to be a safe alternative to conventional CRISPR/Cas9 methods.
