An enzyme derived from the CRISPR system could become a weapon against certain cancer cells. CRISPR is a tool inspired by a natural mechanism used by bacteria to recognize and cut a precise fragment of genetic material.
In laboratories, this system is usually used to modify DNA in a targeted manner. Here, its function is not to correct the genome, but to destroy it after detecting a precise signal.
Image Wikimedia
This enzyme, called Cas12a2, can be programmed to recognize an RNA characteristic of a diseased cell. Once this signal is detected, it triggers a massive fragmentation of chromatin, which contains the DNA. The mechanism acts like a molecular switch. As long as the targeted RNA remains absent, the enzyme stays inactive. When it appears, Cas12a2 causes numerous breaks in the genome of the affected cell.
The researchers notably targeted mutations affecting TP53, a gene frequently altered in cancers. Some of these mutations remain difficult to treat with conventional drugs. The team also targeted anomalies linked to the EGFR gene and high activity of the MYC gene. These signatures can distinguish tumor cells from neighboring healthy cells.
In cell cultures, activation of Cas12a2 slowed proliferation and triggered death of targeted cells. Cells lacking the targeted RNA were more spared.
Tests on mice were also conducted. The enzyme and its guide RNA were transported by lipid nanoparticles to liver or lung tumors. Researchers observed a reduction in tumor burden in these models. These results remain preclinical and do not yet demonstrate efficacy in humans.
This approach thus transforms CRISPR into a tool for selective destruction rather than a simple genetic editor. It opens a new method to eliminate mutations considered difficult to target.