Editing cells’ genomes with CRISPR-Cas9 might increase the risk that the altered cells, intended to treat disease, will trigger cancer, two studies published on Monday warn — a potential game-changer for the companies developing CRISPR-based therapies.
In the studies, published in Nature Medicine, scientists found that cells whose genomes are successfully edited by CRISPR-Cas9 have the potential to seed tumors inside a patient. That could make some CRISPR’d cells ticking time bombs, according to researchers from Sweden’s Karolinska Institute and, separately, Novartis.
CRISPR has already dodged two potentially fatal bullets — a 2017 claim that it causes sky-high numbers of off-target effects was retracted in March, and a report of human immunity to Cas9 was largely shrugged off as solvable. But experts are taking the cancer-risk finding seriously.
Another leading CRISPR scientist, who asked not to be named because of involvement with genome-editing companies, called the new data “pretty striking,” and raised concerns that a potential fatal flaw in some uses of CRISPR had “been missed.”
On the other hand, the Novartis paper has been available in preliminary form since last summer, and CRISPR experts “haven’t freaked out,” said Erik Sontheimer of the University of Massachusetts Medical School, whose CRISPR research centers on novel enzymes and off-target effects. “This is something that bears paying attention to, but I don’t think it’s a deal-breaker” for CRISPR therapies.
Read full, original post: A serious new hurdle for CRISPR: Edited cells might cause cancer, find two studies