US researchers modify ‘molecular scissors’ to edit RNA

By Barry Eitel

SAN FRANCISCO (AA) – U.S. researchers announced Wednesday that they have expanded the powerful gene-editing CRISPR tool to also edit RNA.

Within cells, RNA is used to transmit information coded within DNA to produce proteins.

Editing RNA can be a crucial new tool for medicine, though, because all changes to RNA within cells are temporary while any use of CRISPR on actual DNA is permanent. Theoretically, editing RNA could help heal short-term conditions like inflammation. RNA degrades after roughly 24 hours, but the CRISPR system could be kept within cells for several months and could continually edit RNA.

The breakthrough was published in the journal Science by scientists from the Broad Institute, a biomedical study facility that is a collaboration between the Massachusetts Institute of Technology and Harvard University. The full name of the system is RNA Editing for Programmable A to I Replacement or REPAIR.

“REPAIR presents a promising RNA editing platform with broad applicability for research, therapeutics and biotechnology,” the researchers wrote in the study.

The scientists are heralding REPAIR as a safer alternative for CRISPR, too, because any mistakes would be short-lived.

REPAIR was used in mammalian cells and has yet to be tested in humans, although its creators hope to work with humans, too.

Also on Wednesday, another team of researchers from the Broad Institute announced another CRISPR breakthrough – the ability to edit single points of DNA. Previously, CRISPR could cut out parts of a strand of DNA, like scissors, but now scientists can actually change the nitrogen bases that make up DNA, known as adenine (A), thymine (T), guanine (G) and cytosine (C).

The research was published in the journal Nature.

Being able to change one of the 3 billion base pairs that make up a strand of human DNA instead of cutting out pieces of the strand will likely be a much safer method to use CRISPR, the researchers believe.