Humanitas Clinical and Research Center, Humanitas University, Milan, Italy
Macrophages are key orchestrators of chronic inflammation. They respond to microenvironmental signals with polarized genetic and functional programmes.M1 and M2 cells represent simplified extremes in a universe of functional states. Available information suggests that some TAM are an M2 population.Polarization of phagocytes sets these cellsin a tissue remodeling and repair mode and orchestrate the smouldering and polarized chronic inflammation associated to established neoplasia. Intrinsic metabolic features and orchestration of metabolism are key components of macrophagepolarization and function.Recent studies have begun to address the central issue of the relationship between genetic events causing cancer and activation of protumour, smouldering, non-resolving tumour-promoting inflammation.New vistas have emerged on molecules associated with M2 or M2-like polarization and its orchestration in cancer. Recently, proof-of-principle has been obtained that targeting TAM can be beneficial in human cancer. Moreover, complement has emerged as a key component of tumor-promoting inflammation.
Bonavita et al. PTX3 is an extrinsic oncosuppressor regulating complement-dependent inflammation in cancer. Cell 160: 700-714, 2015.
Mantovani A, Allavena P. The interaction of anticancer therapies with tumor-associated macrophages. J Exp Med. 2015 Apr 6;212(4):435-445.
Mantovani et al.Tumor-associated macrophages as treatment targets in oncology. Nature Rev, Clin. Oncol. In press.