Bioengineers have created bacteria that can detect tumor DNA
Researchers have used genetically modified bacteria to detect tumor DNA in a living organism.Bioengineers from the US and Australia have developed bacteria capable of identifying certain DNA sequences and mutations outside of cells using CRISPR-based genetic editing technology. Using their system, the researchers detected cancer in the colon of mice.
Tumors release their DNA into the environment during development. Many technologies can analyze purified DNA in the lab, but they cannot detect it where it is released to quickly localize tumors.
Many bacteria can absorb DNA from their environment. The researchers used Acinetobacter baylyi bacteria, which are common in the large intestine, as the basis. They modified these microorganisms to make them sensitive to mutant copies of the KRAS gene, which is linked to many cancers.
When confronted with such a gene, the bacteria become resistant to antibiotics. This means that only bacteria that consume mutant forms of KRAS will survive to signal or respond to disease.
The researchers tested the method on mice, some of which had colon cancer. The analysis showed that the bacteria that absorbed the tumor DNA formed "green bacterial colonies that gained the ability to grow on cups of antibiotics."
Bioengineers are working on adopting this method for use as a biosensor in humans. They believe that a similar system will eventually be suitable not only for diagnosing cancer, but also for detecting viral and bacterial infections.