New CRISPR destroys cancer and infected cells, spares the rest

The CRISPR most people have heard of works like a pair of molecular scissors, snipping DNA to fix the genetic roots of disease. A new kind works more like a paper shredder—and according to research co-led by the U’s Spencer Fox Eccles School of Medicine, it could one day fight cancer and viruses by destroying sick cells while sparing healthy ones.

The tool relies on a recently discovered protein called Cas12a2. Researchers can program it to recognize a genetic sequence specific to cancer cells or virus-infected cells. Once it locks onto that target, it rips the cell’s DNA apart until the cell self-destructs.

“Its goal is not to correct anything,” says Yang Liu, assistant professor of biochemistry. “Instead, it’s to destroy anything it sees.”

The lab results were striking. Aimed at a cancer-causing mutation, Cas12a2 cut the growth of human lung cancer cells by 50 percent—about as well as the chemotherapy drug cisplatin. The difference, Liu says: “It does not touch the healthy cells. So if we’re thinking about a cancer therapy, you’re treating cancer with no side effects.” Aimed at the human papillomavirus, which can cause cervical cancer, it cut infected-cell growth by more than 90 percent and slowed infected tumors in mice.

There’s still a long way to go: most testing so far has been on cells in a dish, and getting enough of the protein to the right parts of the body will be a fundamental challenge. Still, Liu imagines uses well beyond cancer and viruses—from neurodegenerative disease to the diseases of aging.

So what’s next for the research? “Curing the incurables,” Liu says.