Chapter 8 - Macrophages and their antitumor activity

Abstract

The tumor microenvironment (TME) plays an important role in the occurrence, development, and progression of tumors. Macrophages are the most abundant cells within the TME and are referred to as tumor-associated macrophages (TAMs) with high plasticity. TAMs can polarize into two distinct functional phenotypes, M1-like and M2-like, based on their specific responses to the TME stimuli. M2-like TAMs form the main subtype of macrophages in most tumors and are involved in tumor occurrence and development and the clinical prognosis of patients bearing tumor. Thus, targeting TAMs is a promising immunotherapy strategy for clinical tumor treatment. This review mainly summarizes the current knowledge on the classification, polarization, and functions of macrophages within the TME. Moreover, it provides an overview of the strategies adopted to deplete or reprogram TAMs for tumor therapy, which will contribute to a better understanding of the relation between TAMs and TME and offer potential targets for anticancer therapy.