doi:10.1155/2012/568783 Review Article Macrophages, Inflammation, and Tumor Suppressors: ARF, a New Player in the Game

Copyright © 2012 Paqui G. Través et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The interaction between tumor progression and innate immune system has been well established in the last years. Indeed, several lines of clinical evidence indicate that immune cells such as tumor-associated macrophages (TAMs) interact with tumor cells, favoring growth, angiogenesis, andmetastasis of a variety of cancers. Inmost tumors, TAMs show properties of an alternative polar-ization phenotype (M2) characterized by the expression of a series of chemokines, cytokines, and proteases that promote immuno-suppression, tumor proliferation, and spreading of the cancer cells. Tumor suppressor genes have been traditionally linked to the regulation of cancer progression; however, a growing body of evidence indicates that these genes also play essential roles in the regulation of innate immunity pathways through molecular mechanisms that are still poorly understood. In this paper, we provide an overview of the immunobiology of TAMs as well as what is known about tumor suppressors in the context of immune responses. Recent advances regarding the role of the tumor suppressor ARF as a regulator of inflammation and macrophage polarization are also reviewed. 1