Scientists have made a breakthrough in treating aggressive forms of cancer by targeting small fragments of rogue DNA that help tumours thrive. A study published in Nature found that many hard-to-treat cancers contain loops of malignant genetic material called extrachromosomal DNA (ecDNA), which makes them harder to treat.
The research, funded through Cancer Grand Challenges, analyzed 39 different tumour types from nearly 15,000 UK patients and found that over one in six cancers had ecDNA. The study identified a new drug, CHK1 inhibitor, that selectively destroys affected cells and prevents tumours from evolving resistance.
EcDNA is formed when fragments break off the chromosomes and form circles of genetic code that sit apart from the chromosomes. It carries cancer-driving genes and suppresses the immune system, allowing tumours to grow and evade treatment. The study found that 17.1% of tumours studied contained ecDNA, with more common in breast, brain and lung cancer.
The researchers discovered that rapid replication of ecDNA drives tumours by increasing their genetic diversity, making them resistant to anti-cancer drugs. However, a CHK1 inhibitor developed by Boundless Bio may selectively destroy tumour cells containing ecDNA, reducing tumours and preventing resistance when given alongside traditional anti-cancer drugs.
“This is not just a discovery about what can make cancer so bad, but actually pointing the way to new treatments,” said Paul Mischel, professor of pathology at Stanford University. “There’s a path forward for developing new therapies because this type of DNA is different and creates vulnerabilities that are different.”
The research offers hope for patients with aggressive cancers who have few treatment options. By targeting ecDNA, scientists may be able to cut the lifeline of these tumours, turning a terrible prognosis into a treatable one.
Source: https://www.theguardian.com/society/2024/nov/06/zapping-rogue-dna-key-treating-aggressive-cancers-study