Tumor-associated macrophages (TAMs) are a type of cell that is found within most tumor masses. Circulating tumor cells (CTC) are shed from a primary tumor and circulate in the bloodstream. Some scientists believe that TAMs derived from primary tumors facilitate CTC seeding of distant metastases. However, the mechanisms of these processes are not well understood.
Dr. Catalona co-authored a study evaluating TAMs as a biomarker of prostate cancer tumors. Researchers used precision microfilters under low-flow conditions to isolate circulating cancer-associated macrophage-like cells (CAMLs) from the blood of patients with breast, pancreatic or prostate cancer. CAMLs are not found in healthy individuals.
The researchers found that CAMLs expressed protein markers. They also discovered these cells bound to CTCs when circulating in the blood. These data support the hypothesis that disseminated TAMs can be used a biomarker of advanced disease, and suggest that TAMs are involved in tumor cell migration.
Adams DL, Martin SS, Alpaugh RK, Charpentier M, Tsai S, Bergan RC, Ogden IM, Catalona W, Chumsri S, Tang CM, Cristofanilli M. Circulating giant macrophages as a potential biomarker of solid tumors. Proc Natl Acad Sci U S A. 2014 Mar 4;111(9):3514-9. doi: 10.1073/pnas.1320198111. Epub 2014 Feb 18