Figure 2.

Markers and polarization of M1-like and M2-like TAMs in the tumor microenvironment. Markers to distinguish between M1-like and M2-like TAMs include transcription factors (white circles), pro-inflammatory molecules secreted by M1-like TAMs, anti-inflammatory molecules secreted by M2-like TAMs (grey rectangles) and cell membrane receptors. M1-like and M2-like TAMs share some common characteristics by secreting the same factors, indicated by the overlay region of the two circles. Pro-inflammatory molecules secreted by M1-like TAMs have tumor cytotoxicity inducing the Th1 response (solid line arrows), and anti-inflammatory molecules secreted by M2-like TAMs trigger the Th2 response (solid line arrows). PGE2 and IL-6 secreted by both M1- and M2-like TAMs are indicated by red letters. Molecules secreted by Th1 and Th2 cell responses induce the polarization of M1- and M2-like TAMs, respectively (dotted arrows). TAM, tumor-associated macrophage; TNF, tumor necrosis factor; RNS, reactive nitrogen species; ROS, reactive oxygen species; NO, nitric oxide; MMP, matrix metalloproteinase; PGE2; CXCL, C-X-C motif chemokine ligand; CCL, C-C motif chemokine ligand; IL, interleukin; TLR, toll-like receptor; MHC, major histocompatibility complex; IFN, interferon; IRF, interferon regulatory factor; NOS, nitric oxide synthase; TME, tumor microenvironment; VCAM, vascular cell adhesion molecule 1; MRC, CD200; Klf, Kruppel like factor; SR, secretin receptor; MR, major histocompatibility complex class I-related; CREB, cyclic AMP-responsive element-binding protein; CSF, colony stimulating factor; VEGF, vascular endothelial growth factor; FGF, fibroblast growth factor; PDGF, platelet-derived growth factor; ARG, Arginase; Ym1, chitinase 3 like 1; PGF2, prostaglandin F; uPA, plasminogen activator, urokinase; MIF, macrophage migration inhibitory factor; GC, glucocorticoid; Fizz1, found in inflammatory zone protein 1; MGL, LLGL scribble cell polarity complex component 1.