- Some cancers are treated with immunotherapy – drugs that attack cancer cells
- Scientists have found a way in which they can increase the effectiveness of the drug
Cancer patients could benefit from a new discovery linking DNA to the success of treatments, after experts uncovered a ‘vital weak spot’ in the devastating disease.
Certain types of cancer are treated with immunotherapy – drugs that harness the body’s natural defenses to attack cancer cells – but with varying degrees of success.
Now scientists have found a way to increase the drug’s effectiveness – and it all has to do with the ‘energy factories’ in tumors.
Every living cell is powered by special compartments called mitochondria, which generate energy.
Experts have discovered that by ‘rewiring’ the DNA of mitochondria, they can make a tumor up to two and a half times more likely to respond to drugs.
They did this by focusing on a common immunotherapy drug called nivolumab – which is used to treat melanoma, lung cancer, liver cancer and colon cancer.
Certain types of cancer are treated with immunotherapy – drugs that harness the body’s natural defenses to attack cancer cells – but with varying degrees of success
It works by releasing a ‘brake’ on the immune system to attack cancer cells.
Experiments showed that nivolumab was up to two and a half times more effective when tumors had high levels of mitochondrial DNA mutations.
This allows doctors to figure out which patients will benefit most from immunotherapy before starting treatment, the scientists said.
But the scientists also believe that mimicking the effects of the DNA mutations could make treatment-resistant cancers more sensitive to immunotherapy, allowing thousands of additional cancer patients to benefit from the drugs.
Co-lead author Dr Payam Gammage, group leader at the Cancer Research UK (CRUK) Scotland Institute and the University of Glasgow, said: ‘Cancer is a disease of our own bodies.
‘Because cancer cells can look like healthy cells on the outside, it is a complicated task to get our immune system to recognize and destroy cancer cells.
‘More than half of cancers have mutations in their mitochondrial DNA. But when we engineered these mutations in the laboratory, we found that tumors with the most mutated mitochondrial DNA are much more sensitive to immunotherapy.
‘Thanks to this research, we now have a powerful tool that offers us a completely new approach to stopping cancer in its tracks.’
The technology behind the discovery is now the subject of patents filed by Cancer Research Horizons, the innovation arm of CRUK.
It will help bring the technology to market so that new treatments can be developed that disrupt the energy sources that cancer uses to spread and grow.
Dr. Iain Foulkes, executive director of research and innovation at CRUK and CEO of Cancer Research Horizons, said: ‘After years of rigorous laboratory research, we have identified a crucial vulnerability in cancer.
‘Mitochondrial DNA mutations are a common component of cancer and this astonishing discovery has limitless possibilities.’
Dr. Ed Reznik, of Memorial Sloan Kettering Cancer Center, also worked on the study.
“This research opens up a whole world where we can rewire tumors’ energy sources – and potentially short-circuit them to defeat cancer earlier,” he added.
The findings were published in the journal Nature Cancer.