The gene editing tool CRISPR, which has been hailed as the potential solution to everything from malaria to early-onset Alzheimer’s to breast cancer, may increase the risk of cancer, according to two papers published Monday in Nature Medicine. Both research teams in question found unexpected effects when cutting up DNA within cells that caused cells to start to go haywire, leading to circumstances that would create cancerous cells.
CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats), which has been in development in one form or another for thirty years, is a system that allows scientists to slice away at DNA within cells, turning certain proteins on or off that change a living thing’s susceptibility to viruses, conditions, or diseases. By editing the DNA of mosquitoes, for instance, researchers can make it difficult for the species to carry malaria, which inhibits its ability to pass it on to people, which could lead to eradication of the disease. Likewise, scientists have used the system to edit DNA directly in humans, in one instance editing a set of human embryos to remove a mutation that is linked to a heart condition that causes sudden death. Not only would the resulting babies not fall victim to this condition, their descendants would not inherit it, either.
According to the two new pieces of research, attempting to edit certain types of cells leads them to freak out and initiate a damage response, a process that can lead to the production of cancerous cells. In one study, the response was triggered in epithelial cells of the eye; in the second, researchers were unable to edit a type of stem cell that works to repair DNA without killing it. This means attempting to edit those types of cells would reduce their population, a situation that is known to let cancerous cells grow out of control since the cells are not around to repair damaged DNA.
The papers both refer to lab tests and not human trials, and CRISPR is a long way away from regular implementation. Still, the unintended side effects of what has so far been presented as relatively straightforward process for eradicating medical problems suggest we may want to slow our roll a tad on the genetic editing.