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Fox Infections like influenza and COVID-19 may do more than cause temporary illness. A new study suggests they can also “wake up” dormant cancer cells, potentially increasing the risk of recurrence and metastasis years after treatment. The research, led by Dr. James DeGregori at the University of Colorado Anschutz Medical Campus, was published July 30 in Nature. Scientists tested how respiratory viruses affect dormant cancer cells using mouse models of breast cancer, and then compared those findings with large patient health datasets. How respiratory viruses reawaken dormant cancer cells

Cancer cells can sometimes break away from the original tumor and linger quietly in other parts of the body for years, a state researchers call dormancy. What causes them to reawaken has long been unclear.

The Colorado team found that in mice, influenza and SARS-CoV-2 infections triggered inflammation that reactivated these cells in the lungs. Within three days of infection, cancer cells began multiplying rapidly, and the effect persisted for months.

The awakening process depended on an inflammatory molecule called IL-6. When mice lacked IL-6, the cancer cells were far less likely to restart growth.

“Dormant cancer cells are like the embers left in an abandoned campfire, and respiratory viruses are like a strong wind that reignites the flames,” DeGregori said.

Blocking brain damage triggered by a glioblastoma, an aggressive brain cancer, may slow the growth of the cancer and allow the brain to keep working better for longer, according to a new study led by UCL (University College London) researchers.

The study, published in Nature and funded by the Brain Tumor Charity and Cancer Research UK, looked at glioblastomas in mice. It found that early-stage tumors damaged parts of nerve cells called axons, and that the brain’s natural response to this injury – breaking down and clearing away these damaged axons – accelerated the tumor’s growth.

Mice in whom this natural response was turned off developed less aggressive tumors, lived for longer and maintained normal brain function that persisted to nearly the end of their lives. In contrast, mice who responded to nerve damage as normal developed more aggressive tumors and progressive disability, the researchers found.

Drugs that block this response, by targeting SARM1, the protein that destroys damaged axons, are already being developed for early phase trials in neurodegenerative conditions in which axons are also damaged, such as traumatic brain injury (TBI) and motor neuron disease (MND).

Senior author Professor Simona Parrinello, of the UCL Cancer Institute, said: “Our study reveals a new way that we could potentially delay or even prevent glioblastomas from progressing to a more advanced state.

“This is especially important as current therapies do not work well for glioblastoma, which is extremely difficult to treat, in part because it is typically diagnosed when it is already very advanced.

“These tumors are also linked to debilitating neurological symptoms. Blocking the brain damage triggered by tumor growth could be beneficial in two ways – by slowing the progression of the cancer and by reducing disability.

“The next step is to see if SARM1 inhibitors already being trialled for other neurodegenerative diseases could also be used to treat this aggressive form of brain cancer. However, we need to do more work in the lab before these inhibitors can be tried in patients with glioblastoma.”

Glioblastomas are the most common form of brain cancer, with about 3,000 people diagnosed in the UK each year. They grow from normal brain cells that develop pathological mutations. The average survival time after diagnosis is about 12-18 months, even with the current best treatment (a combination of surgery, chemotherapy and radiotherapy).

In the new study, the researchers sought to investigate how the tumors formed and evolved in their earliest stages. These early states of the disease are not well understood as the tumors tend to be discovered only when they are more developed. As it is rare to identify and access samples from patients with early-stage disease, the researchers used mice whose genes had been edited to grow glioblastomas comparable to human tumors to look at these early disease states.

They found that the tumors expanded preferentially in the brain’s white matter regions, which are rich in axons (long, thread-like extensions that connect nerve cells). The tumors compressed and injured the axons, triggering a process called Wallerian degeneration, in which SARM1 breaks down these damaged axons by destroying their source of energy (a molecule called NAD⁺).

This process, which increased inflammation in the brain, coincided with the tumors becoming more aggressive, suggesting they used the brain’s response to injury as fuel for their own growth.

The researchers found that inducing injury to axons in mice accelerated the progression of the tumor. They also found that, among mice whose SARM1 gene had been de-activated and whose axons did not get broken down so quickly, the tumors stayed in a less aggressive state.

Our findings show that there is an early stage of this disease that we might be able to treat more effectively. By interfering with the brain’s response to injury before the disease becomes intractable, we can potentially change how tumors behave, locking them in a more benign state.”

Mr. Ciaran Hill, Senior co-author, UCL Cancer Institute and consultant neurosurgeon at UCLH

The researchers said that this study opens up new areas of investigation linking brain cancer and neurodegeneration, and paves the way for future treatment strategies aimed at earlier intervention.

Gigi Perry-Hilsdon, Chair of The Oli Hilsdon Foundation, which raises funds for research into glioblastoma in loving memory of Oli*, said: “We know all too well the devastating statistics that currently exist in relation to glioblastoma, alongside the urgent need for better treatments.

“We are therefore immensely proud to have funded this pioneering research, led by Professor Simona Parrinello, in partnership with the Brain tumor Charity. Her team’s unique approach to tackling this devastating disease at its early stages inspired us and gives hope that a breakthrough treatment is a possibility.” 

Research information manager at Cancer Research UK, Tanya Hollands, said: “Glioblastoma is a fast-growing type of brain tumor that’s difficult to treat, and people diagnosed with the disease face a poor prognosis.

“This fascinating research offers a fresh perspective on how glioblastomas grow and affect the brain. Uncovering how the brain’s response to damage may help fuel tumor growth opens a potential new avenue for treatment.

“While this work is still in its early stages and has so far only been demonstrated in mice, it lays important groundwork for developing treatments that could not only extend life, but also improve patients’ quality of life by preserving brain function for longer.”

*Gigi’s husband Oli was diagnosed with a glioblastoma at the aged of 22 and given less than 12 months to live. But he coped with his diagnosis with “optimism, courage and a wicked sense of humour”. He ran the London Marathon in under four hours, worked full time, travelled the world and got married. He died in January 2019, just 10 days before his 27th birthday. His family pledged to raise £1.5m towards Professor Parrinello’s research – and met their target a year early.