A team of researchers at Tel Aviv University’s Gray Faculty of Medical and Health Sciences has uncovered a way that cancerous tumors manipulate a routine immune system function to help themselves grow — a finding that scientists say could pave the way for new treatment strategies aimed at restoring the body’s natural ability to fight cancer.
The study was led by Dr. Merav Cohen alongside doctoral students Roi Balaban and Ori Moskowitz, and the results were published in the scientific journal Science Immunology.
At the center of the research are macrophages — immune cells whose normal job is to clean up dead and damaged cells in the body. Under healthy conditions, this cleanup process helps keep tissue functioning properly and reduces inflammation. However, the researchers discovered that inside tumors, this same process can alter the behavior of those immune cells in ways that actually benefit the cancer.
To study this phenomenon, the research team created a new tool called Effero-seq, a technology designed to track what happens to immune cells after they absorb dead cells. Using this method, the scientists observed that macrophages that consumed dead cancer cells underwent what the researchers called a “reprogramming” — switching on genes linked to tumor development.
Working with a melanoma model, the team examined what these altered immune cells actually do inside a tumor. They found that macrophages that had absorbed dead cancer cells began promoting the growth of new blood vessels within the tumor. Those new vessels delivered oxygen and nutrients to the tumor, enabling it to expand more quickly. On top of that, these same macrophages became less sensitive to signals that would normally activate the immune system’s cancer-fighting response.
The researchers also extended their analysis to human patients, looking at data from individuals diagnosed with uveal melanoma, a type of eye cancer. They found that patients whose tumors showed a higher presence of immune cells carrying the genetic signature identified in the study tended to have lower survival rates.
Dr. Cohen said the results shed important new light on how tumors are able to manipulate the immune system for their own benefit.
“The better we understand these mechanisms, the better equipped we will be to develop treatments that block them and restore the immune system’s ability to fight cancer,” she said. “This research points to a new and promising therapeutic target, one that focuses not only on the cancer cells themselves, but also on the processes that enable them to thrive.”
