Therapeutic potential of tumor associated macrophages

It is well established that in addition to the uncontrolled proliferation of the neoplastic cells, the initiation and progression of tumors are accompanied by and dependent on the evolvement of the tumor microenvironment. As the major components of tumor-infiltrating host cells, tumor-associated macrophages (TAMs) exhibit potent anti-inflammatory and pro-survival properties in the context of cancer. In the primary tumor, they boost neovascularization, suppress antitumor immunity and enhance the invasiveness of neoplastic cells. During metastasis, the tumor-educated macrophages prime the suitable “soil” for tumor seeding and provide potent support for their metastatic growth. In this review, we describe and discuss recent advances in the understanding of the contribution that TAMs make to the survival and progression of neoplasms and their underlying mechanisms. On this basis, we discuss the therapeutic strategies targeting TAMs that complement and synergize with traditional regimens in patients with different types of cancer.