Scientists Develop Programmable Chemotherapy to Destroy Cancer Cell DNA

The Molecular Kill Switch: How Cas12a2 Targets Cancer

Scientists have developed an innovative strategy to combat cancer by utilizing a specialized enzyme from the CRISPR immune system. This enzyme is capable of destroying the DNA of cancer cells and inducing them to self-destruct.

The approach explores an enzyme that can be programmed to identify a specific messenger RNA—such as one produced by a tumor cell—and fragment the entire genome upon finding its target. According to researchers, the technique offers a new way to eliminate cells that produce mutant proteins traditionally considered undruggable by conventional medicines.

It’s a molecular kill switch that recognizes a particular RNA. This is basically a programmable chemotherapy. Yang Liu, molecular biologist at the University of Utah School of Medicine

That perspective is detailed in two studies published in Nature, outlining how the system works against hard-to-treat malignancies. A biotechnology company based in Zwingenberg, Germany, called Akribion Therapeutics, is already advancing an experimental therapy using this approach to target head and neck cancers associated with human papillomavirus (HPV). Paul Scholz, co-founder and head of research and development at Akribion, notes that the company’s goal is to produce the first clinical trial data by 2030.

Uncovering the Wild Behavior of Bacterial Defenders

CRISPR systems occur naturally in bacteria and microorganisms as a protective immune defense. They use RNA molecules to direct CRISPR-associated Cas enzymes to the DNA of invading viruses so the material can be cut and destroyed. For over a decade, scientists have adapted these systems for gene editing by designing guide RNAs that direct Cas enzymes to specific genomic sites.

Not all Cas enzymes operate identically, however. Nearly ten years ago, Ryan Jackson, a biochemist at Utah State University, set out with his colleagues to study the mechanism of a protein called Cas12a2. The team initially assumed it would behave like other editing enzymes.

Ryan Jackson, biochemist at Utah State University, recalled that they noted the system was not behaving the way they wanted, adding that he even accused his students of contaminating the protein.

Subsequent laboratory work revealed that Cas12a2 possesses a radically different behavior. Once it recognizes an RNA sequence matching its guide RNA, the enzyme destroys DNA indiscriminately, halting cell growth. In nature, this mechanism stops infections from spreading through a bacterial population. As Rene Bernards, a cancer geneticist at the Netherlands Cancer Institute, put it, How the hell does nature come up with a trick like that? But, whatever. We can make good use of it.

Directing the Enzyme Against Mutant TP53 and KRAS Genes

Two separate research teams adapted this natural defense mechanism to target tumors driven by genetic mutations that resist conventional treatments. One group directed Cas12a2 toward RNA produced by cells carrying mutations in the TP53 gene, which is altered in up to half of all cancers. The other team targeted RNA derived from a mutated version of the KRAS gene, whose altered proteins drive rapid, uncontrolled cell growth in some of the deadliest cancers.

In experimental tests conducted on human cell culture and in mice, the Cas12a2 system demonstrated high precision. It eliminated only the cells bearing the cancer-related mutations, even when the difference compared to normal RNA was a single letter. In animal models, the technique successfully shrank tumors linked to mutant TP53 and HPV.

While Baojun Wang, a synthetic biologist at Zhejiang University, emphasizes that a significant distance remains between these laboratory experiments and a therapy ready for human use, the work establishes a striking proof of concept for the technology.

How Proteins Aid Cancer Survival

The broader challenge of treating stubborn cancers involves understanding how tumor cells evade standard therapies. Research published in Genes & Development highlights that abnormal proteins do more than simply drive tumor growth.

Scientists at the Oregon Health & Science University discovered that the MYC protein—which is abnormally active in the majority of human cancers—directly assists in repairing damaged DNA. This DNA repair mechanism allows tumor cells to recover from chemotherapy and other treatments designed to eradicate them, pointing to additional survival pathways that future therapies must overcome.