Regulation of epithelial-mesenchymal transition by tumor-associated macrophages in cancer

It should be urgently better understood of the mechanism that contributes cancer aggressiveness. Epithelial-mesenchymal transition (EMT) plays a fundamental role in tumor progression and metastasis formation by invasion, resistance to cell death and senescence, resistance to chemotherapy and immunotherapy, immune surveillance, immunosuppression and inflammation, confers stem cell properties. Tumor-associated macrophages (TAMs) are key orchestrators and a set of macrophages in tumor microenvironment. They are major players in the connection between inflammation and cancer. TAMs could promote proliferation, invasion and metastasis of tumor cells, stimulate tumor angiogenesis, and inhibit anti-tumor immune response mediated by T cell followed by promoting tumor progression. Recently, studies showed that TAMs played critical role in the regulation of EMT in cancer, although the underlying mechanism of TAMs-mediated acquisition of EMT has been largely unclear. This review will discuss recent advances in our understanding of the role of TAMs in the regulation of EMT during tumorigenesis and summarize the recent ongoing experimental and pre-clinical TAMs targeted studies.