Researchers engineer CRISPR to edit single RNA letters in human cells

The Broad Institute and MIT scientists who first harnessed CRISPR for mammalian genome editing have engineered a new molecular system for efficiently editing RNA in human cells. 

RNA editing, which can alter gene products without making changes to the genome, has profound potential as a tool for both research and disease treatment.

In a paper published today in Science, senior author Feng Zhang and his team describe the new CRISPR-based system, called RNA Editing for Programmable A to I Replacement, or "REPAIR." The system can change single RNA nucleosides in mammalian cells in a programmable and precise fashion. REPAIR has the ability to reverse disease-causing mutations at the RNA level, as well as other potential therapeutic and basic science applications.

"The ability to correct disease-causing mutations is one of the primary goals of genome editing," said Zhang, a core institute member at the Broad Institute and investigator at the McGovern Institute for Brain Research at MIT. "So far, we've gotten very good at inactivating genes, but actually recovering lost protein function is much more challenging. This new ability to edit RNA opens up more potential opportunities to recover that function and treat many diseases, in almost any kind of cell."

Unlike the permanent changes to the genome required for DNA editing, RNA editing offers a safer, more flexible way to make corrections in the cell. "REPAIR can fix mutations without tampering with the genome, and because RNA naturally degrades, it's a potentially reversible fix," explained co-first author David Cox, a graduate student in Zhang's lab.