Researchers at the Emory University School of Medicine have revealed that boosting the production of a blood pressure-regulating enzyme could enhance the immune system's ability to sense tumour growth.
For their study, the researchers engineered mice that make more angiotensin-converting enzyme (ACE) in white blood cells called macrophages.
The team found that the mice could more effectively inhibit the growth of injected tumours.
ACE plays a critical role in controlling blood pressure and is the target of common medications.
"We think we've discovered a means of tweaking the immune response by modifying the process of antigen presentation," said Dr Kenneth Bernstein, senior author, Emory distinguished service professor of pathology and laboratory medicine.
The researchers, created mice with a genetic alteration in the ACE gene, forcing the gene to be turned on only in macrophages.
When the mice were further injected with several types of melanoma or lymphoma, they developed smaller tumours. The tumours they did have contained more white blood cells attacking the cancerous cells.
ACE works by "trimming" small bits of protein originating from the tumours, thus allowing the immune system to sense tumours and enhance the effective response.
The study is published online in the Journal of Biological Chemistry (JBC).