Scientists create smart DNA drug that targets cancer cells with high precision
Researchers developed a smart DNA drug that activates only when two cancer markers are present on a cell. In laboratory experiments, it delivered potent drugs to cancer cells while sparing nearby healthy cells.
Researchers at the University of Geneva have developed a smart DNA drug built from synthetic DNA strands that can identify cancer cells with remarkable accuracy and release powerful drugs only where they are needed. The findings appear in Nature Biotechnology, where the system was described as a programmable approach that targets cancer while sparing healthy cells.
Targeted therapies have already reshaped cancer care by directing drugs straight to tumors, helping reduce damage to healthy cells and easing harsh side effects linked to chemotherapy. One of the most successful strategies involves antibody-drug conjugates, which use monoclonal antibodies to carry treatments directly to cancer cells, but their relatively large size can limit how well they penetrate tumors and they can only carry a limited amount of drug.
To overcome these limitations, the team designed a system based on short DNA strands. Because these molecules are much smaller than antibodies, they can move more easily through tumor tissue, and they can be engineered to carry multiple components.
The new method relies on several separate DNA strands, each carrying a specific function. Some strands include binders that recognize cancer markers, while another carries a toxic drug. When two distinct cancer markers are present on a cell, the DNA components attach to them and assemble at that exact location, triggering a chain reaction that builds up more DNA structures at the site and boosts the amount of drug delivered.
The process works much like two-factor authentication. Both markers must be detected before activation occurs. If one is missing, the reaction does not begin, and the drug remains inactive.
In laboratory experiments, the system successfully identified cancer cells with specific combinations of surface proteins and delivered potent drugs directly to them. Nearby healthy cells were not affected. The researchers also showed that multiple drugs can be delivered together using this approach, which could be important for preventing or overcoming resistance, a common problem in cancer treatment.
The system works using the same kind of basic logic found in computing. In this case, an "and" logic gate ensures that the drug activates only when both cancer markers are present. Researchers said future work could expand the concept by adding more complex logic functions, with the goal of medicines that behave like programmable systems and make more advanced decisions inside the body.