When Yoshizumi Ishino and his colleagues from Osaka University discovered an odd DNA sequence of E. coli in 1987, they had no idea what they had stumbled upon. The sequences were palindromic — reading the same forward and backward — but the scientists didn’t understand their function. They made note of the oddity in their completed study.
Fast forward a few years later, and researchers find that the sequence allows bacteria to prevent viral infections. When the bacterium detects the presence of virus DNA, it produces an RNA that matches that of the virus. When this sequence finds its target within the virus, the target DNA is cut and the virus is disabled. By harnessing this natural technique, researchers realized they could precisely cut any type of DNA and conduct specific genome editing. This would have a direct impact on genetic disease therapies, effectively providing a tool kit to fix mutated genes.
“It’s a huge argument that basic, fundamental science needs to be funded. This was a study to see how bacteria deal with viruses, with no thought that it would have any human-health implications,” says Terry Magnuson, geneticist and UNC Vice Chancellor for Research. “It turned out to be probably one of the most revolutionary findings that has ever happened.”
Commercially available since 2012, CRISPR-Cas9 (CRISPR) edits genes by cutting DNA and letting natural processes repair those divides. This allows scientists to add, remove, or alter particular parts of an organism’s genome. Think of it as a geneticist’s “copy and paste” tool. More precise and inexpensive than previous genome engineering, the attributes that make it widespread in the scientific community also expedite the need for ethical consensus among users.
“What happens when the preventive interventions you imagine raise the same kinds of ethical questions that enhancements do?” asks Eric Juengst, director of the UNC Center for Bioethics. “Questions about equal access, effects on the downstream generations, and effects on what it means to be human.”
Juengst explores these and other ethical quandaries as they relate to this gene-editing tool. His work focuses on research ethics — questions raised by new advances in science and technology. He and his colleague, Jean Cadigan, are leading a project that will survey scientists about the professional and social factors that shape the trajectories of using CRISPR in preventive human genome editing, as well as analyzing national and international policy.
Fortunately, this isn’t completely new territory for bioethicists, researchers, and policymakers. Genome engineering has been around for decades. Methods like homologous recombination, developed by Nobel laureate and UNC’s own Oliver Smithies, have prompted ethical discussions time and time again.
Most agree upon the implications behind this technology and the need to proceed with caution. If used responsibly, though, CRISPR can forever alter the way scientists study genes.
“CRISPR’s ability to change the way research is done is comparable to the electron microscope — everybody depends on it now for all kinds of research,” Juengst says. “That’s the sort of impact that this technique could have on basic [science] research.”