Angiotensin converting enzyme expression on circulating immune cells from colorectal cancer patients correlates with the disease stage. Results from a preliminary study.

Colorectal cancer (CRC) is the third most common cancer and the second leading cause of cancer-related mortality worldwide. Because CRC is a very complex disease, sometimes patients at same disease stage are treated with combinations of systemic therapy and surgery leading to different outcomes. Immune T and B cells infiltrating the tumor has been associated with disease-free survival, cancer-specific survival and overall survival. In the opposite, Myeloid-derived suppressor cells infiltrating the tumor has been linked to poor outcome. The peripheral blood evaluation of immune cells is less invasive, easy to be performed in different CRC follow-up visits, and could be used as a guide for therapy interventions. The expression of angiotensin converting enzyme (ACE) in immune cells can be used as a biomarker for cancer prognosis an also as a target for cancer treatment since ACE expression in macrophages and neutrophils has been related to improved immunity. Our aim therefore was to investigate the expression of ACE in subsets of T, B, and myeloid-derived suppressor cells in peripheral blood from CRC patients. We found that the expression of ACE is increased in Naïve and Effector T cells and in Effector B cells of CRC patients stage III. These findings open opportunities for targeting ACE in immune cells as a new therapy in colorectal cancer.