Medical Bulletin 30/January/2024

Here are the top medical news of the day:

Liquid biopsies to detect Neuroblastoma relapse of childhood cancer early

Cancer Research UK-funded scientists have made an unusual discovery that could help to identify patients who are up to two and a half times more likely to respond to currently available cancer drugs.

Scientists at the Cancer Research UK Scotland Institute and Memorial Sloan Kettering Cancer Centre in the USA have “rewired” the DNA of mitochondria – energy factories found in every living cell. They found that creating mutations in parts of this DNA determines how well cancer will respond to immunotherapy – treatments which harness the body’s natural defences to attack cancer cells.

This discovery opens up new ways to identify patients who could benefit most from immunotherapy by testing for mitochondrial DNA mutations. Half of all cancers have mitochondrial DNA (mtDNA) mutations and this discovery shows for the first time that they could be exploited to improve cancer treatment.

In the future, combining treatments that mimic the effect of these mutations with immunotherapy could increase the chances of successful treatment for multiple types of cancer.

In a paper published in the journal Nature Cancer, the scientists demonstrate for the first time a direct link between mitochondrial DNA (mtDNA) mutations and response to cancer treatment. Surprisingly, they found that tumours with high levels of mtDNA mutations are up to two and a half times more likely to respond to treatment with an immunotherapy drug called nivolumab.

Reference: Cancer treatment two and a half times more effective when tumours have defective "energy factories"; Nature Cancer; DOI: 10.1038/s43018-023-00721-w

Obesity dismantles our mitochondria, here is the answer

The number of people with obesity has nearly tripled since 1975, resulting in a worldwide epidemic. While lifestyle factors like diet and exercise play a role in the development and progression of obesity, scientists have come to understand that obesity is also associated with intrinsic metabolic abnormalities. Now, researchers from University of California San Diego School of Medicine have shed new light on how obesity affects our mitochondria, the all-important energy-producing structures of our cells.

In a study published (January 29, 2023) in Nature Metabolism, the researchers found that when mice were fed a high-fat diet, mitochondria within their fat cells broke apart into smaller mitochondria with reduced capacity for burning fat. Further, they discovered that this process is controlled by a single gene. By deleting this gene from the mice, they were able to protect them from excess weight gain, even when they ate the same high-fat diet as other mice.

Reference: How obesity dismantles our mitochondria; Nature Metabolism; DOI:10.1038/s42255-024-00978-0

Neuroblastoma: Liquid biopsies to detect relapse of childhood cancer early

Neuroblastoma mainly affects toddlers and young children - in the EU region there are 1500 new cases per year. Neuroblastoma is a malignant tumor of the peripheral nervous system and around 50% of patients are high-risk cases. Recurrences occur frequently, and conventional therapies are no longer effective for these children. With liquid biopsies it is possible to monitor therapy success and to predict the recurrence of the tumor in time to take medical countermeasures.

Scientists from leading European research institutions in paediatric oncology are testing this promising diagnostic tool under the coordination of the European Society for Pediatric Oncology (SIOPE) and scientific lead of the Princess Máxima Center for pediatric oncology and St. Anna Children's Cancer Research Institute. The framework is a five-year Horizon Europe project.

Reference: Neuroblastoma: Liquid biopsies to detect relapse of childhood cancer early