High-intensity electrical pulses have been medically used to destroy tumors while sparing healthy tissue. But lower-intensity pulses may have a different effect — they reshape the battlefield, making tumors more vulnerable to the body’s own defenses.
A breast tumor (in blue) grows within the surrounding mammary tissue (in red), while lymphatic vessels (in green) form a network around it. Image credit: Jennifer Munson / VirginiaTech
According to Virginia Tech researchers at the Fralin Biomedical Research Institute at VTC, these lower-intensity pulses don’t kill all the cancer cells outright. Instead, they alter the tumor’s environment, increasing blood vessel density within a day of treatment and boosting lymphatic vessel growth by day three.
These changes may help guide immune cells to the tumor, potentially improving the body's natural ability to fight cancer.
The findings in mouse models of breast cancer were published in a recent issue of the Annals of Biomedical Engineering. Researchers looked at a lower-intensity version of a treatment called high-frequency irreversible electroporation (H-FIRE) that destroys tumors using electrical pulses. It also helps the immune system recognize and attack cancer cells by changing the environment around the tumor.
While a previous version of this technique was known to increase blood vessel growth and immune cell activity in the parts of the tumor that weren’t completely destroyed, scientists didn’t fully understand how these electric pulse treatments affect the lymphatic system, which plays a key role in immune responses.
With the new study, researchers used a mouse model of breast cancer to examine changes in blood and lymph vessels in and around the tumor, as well as in nearby lymph nodes.
Scientists found blood and lymphatic vessels benefited from a lower-intensity version of H-FIRE, called sub-ablative H-FIRE. The tumor itself wasn’t immediately destroyed, but the study suggests that these vascular changes might make the cancer more vulnerable to the body’s natural defenses and potentially enhance the effects of additional therapies.
“These findings illustrate that after treatment, the tumor’s blood and lymphatic vessels change in ways that could help the immune system respond more effectively,” said Jennifer Munson, the corresponding author of the study and director of the Fralin Biomedical Research Institute Cancer Research Center in Roanoke. “One key change is an increase in signals that may direct immune cells toward the tumor through the lymphatic system.”
The study was supported by the National Cancer Institute, the National Center for Advancing Translational Science, and the National Institute of Biomedical Imaging and Bioengineering, all part of the National Institutes of Health.
Future research may focus on how the remodeling of these vessels affects immune activity and whether combining this treatment with other therapies could improve cancer treatment, said Munson, a professor with the research institute and the Department of Biomedical Engineering and Mechanics in the College of Engineering.
Source: VirginiaTech