A new study shows how aggressive brain cancers ‘hijack’ the body’s immune system to promote tumour growth.

Published in Cancer Discovery, the findings by The Wistar Institute in the United States of America under the title “Functional reprogramming of neutrophils within the brain tumor microenvironment by hypoxia-driven histone lactylation,”also identify a potential way to counteract this effect and slow tumour progression in animal models.

Brain and nervous system tumours are among the most lethal forms of cancer, with only one in three patients surviving beyond five years after diagnosis. Despite the availability of various immunotherapies designed to stimulate the immune system as a part of treatment, they have largely been ineffective. Researchers now believe this failure occurs because the cancer itself hijacks the body’s immune response, using it to sustain its own growth and evade treatment.

The ‘evasion’ is thought to involve CD71 neutrophils, a type of white blood cell that initially infiltrates tumours to defend the body against cancer. However, if the tumour survives this immune attack, it begins recruiting these neutrophils to shield itself from further immune responses.

To counteract this attack, the research team tested a compound – ‘building blocks’ of life such as water and carbon dioxide – called isosafrole in combination with immunotherapy. They found that this combination successfully prevented the conversion and enhanced the body’s ability to fight the cancer.

“Our work reveals the step-by-step process by which brain tumours transform neutrophils into barriers against treatment,” said Dr Filippo Veglia from the Wistar Institute. “Now that we understand this reprogramming, we can disrupt it. Preclinical data already show that isosafrole treatment can reverse neutrophil reprogramming, making otherwise resistant brain tumours responsive to immunotherapy.”

While this breakthrough was demonstrated in animal models, it paves the way for future clinical studies in human patients with brain cancer and potentially other cancers resistant to immunotherapy, Dr Veglia added. “We are eager to see how future research refines this strategy to combat some of the deadliest cancers.”

The study ‘Functional reprogramming of neutrophils’ can be found here