Stress is an inevitable aspect of life. But excessive stress can have detrimental effects on our health. Long-term stress increases the risk of heart disease and stroke. It may also encourage the spread of cancer. How it works remains a mystery; A challenge for cancer treatment.

“We cannot prevent stress in cancer patients,” says Xue-Yan He, former postdoctoral researcher in Assistant Professor Mikala Egeblad’s laboratory at Cold Spring Harbor Laboratory (CSHL). You can imagine that if you were diagnosed, you wouldn’t be able to stop thinking about the disease, insurance, or family. That’s why it’s so important to understand how stress affects us.”

Now Vin and Egeblad may have made some progress in understanding just that. Working with CSHL professor Linda Van Elst, they discovered that stress causes certain white blood cells called neutrophils to form sticky web-like structures that make body tissues more susceptible to metastasis. This discovery could point to new treatment strategies to stop the spread of cancer before it starts.

Stress-induced metastases in mice

The team reached their discovery by simulating chronic stress in mice with cancer. First, they removed tumors that were growing in the mice’s breasts and spreading cancer cells to their lungs. They then exposed the mice to stress. What he saw was shocking.

“He saw this terrible increase in metastatic lesions in these animals. Metastases increased up to fourfold,” Egeblad recalls.

The team found that stress hormones called glucocorticoids affect neutrophils. These “stressed” neutrophils formed mesh-like structures called NETs (neutrophil extracellular traps). NETs form when neutrophils shed DNA. They can often protect us from invading microorganisms. However, in cancer, NETs create a suitable environment for metastasis.

Potential for new treatment strategies

He performed three tests to confirm that stress causes the formation of NETs, ​​which in turn leads to increased metastases. First, he removed neutrophils from mice using antibodies. He then injected the animals with a drug that destroyed the NETs. Finally, he used mice whose neutrophils did not respond to glucocorticoids. The same results were obtained in each test. “The stressed mice no longer developed metastases,” he says.

Specifically, the team found that chronic stress triggered the formation of NETs that would alter lung tissue, even in mice without cancer. “It almost sets your tissue up for cancer,” Egeblad explains.

According to Van Elst, the meaning of this is obvious, though striking. “Stress reduction should be a component of treatment And “preventing cancer,” he says.

The team also suggests that future drugs that prevent NET formation could benefit patients whose cancer has not yet metastasized. Such new treatments could slow or stop the spread of cancer and provide much-needed relief.