Representing Tumor-Associated Macrophages as the Angiogenesis and Tumor Microenvironment Regulator

Over the recent years, studies in the area of cancer microenvironment and the cellular groups existing in this environment have indicated the significant role of them in progression of cancer studies. Among the mentioned cellular groups, as the main inflammatory components of stroma, Tumor associate macrophage (TAM) cells have the capacity of affecting the cancer tissue in different aspects. With their plasticity capacity, macrophages can change into M1 (classic) or M2 (alternative) macrophage reacting to different signals.  In the tumor environment, they usually change into the M2 phenotype, and this phenotype can create a precancerous role in the macrophage and facilitate the invasion of tumor cells and metastasis, angiogenesis, remodeling of the extracellular matrix, and suppression of the immune system. The various roles of these cells and their reversibility have made the TAMs a potential target of the cancer treatment. This process takes place by different mechanisms such as Interference with TAMs survival, Inhibition of macrophage recruitment, repolarization of M2-like TAMs towards an M1-like phenotype, nano particle and liposome-based drug delivery system. This review study investigates the markers and the function of M1, M2, and tumor-associated macrophages, and finally, it proposes the latest clinical and laboratory approach for targeting the TAMs.