Tumor-associated macrophages (TAMs) promote tumor progression and inhibit anti-tumor immune response by producing various mediators and preferentially express CD163, CD204, and CD206.
In addition, we investigated serum soluble (s)CD163, chemokine (C-X-C motif) ligand 10 (CXCL10) and chemokine (C-C motif) ligand 2 levels at several time points of tumour progression in these patients, revealing serum levels of sCD163 and CXCL10 as potential biomarkers for progression of CAS.
Furthermore, Pearson's correlation analysis revealed that PFKFB3 was signifcantly correlated with both CD163 and CD31 (P<0.05), meanwhile CD163 was signifcantly correlated with CD31 (P<0.001), suggesting PFKFB3 may promote angiogenesis in tumor progression and metastases by regulating CD163+ TAMs infiltration in OSCC.
Recent findings have shown the significance of CD163-positive macrophages in tumor progression, yet there have been few studies on the function of CD163 in macrophages.
However, it was found a positive correlation between SAA1 and genes involved in tumor progression, such as: HIF1A (r = 0.50; p < 0.00001), CD163 (r = 0.52; p < 0.00001), CXCR4 (r = 0.42; p < 0.00001) and CXCR7 (r = 0.33; p = 0.002).
These CD14(+) CD16(+) monocytes were suggested to enhance tumour progression as this subpopulation possesses (i) high expression of adhesion molecules (CD11c, CD49d, and CD54) and scavenger receptor (CD163), which enable them to adhere strongly to endothelial cells, and (ii) that peripheral blood monocytes from CCA patients express high levels of growth and angiogenic factor-related genes (epiregulin, VEGF-A and CXCL3).
This represents the first report investigating the tumor immune microenvironment as a prognostic factor in synovial sarcoma, indicating that CD163+ macrophages are associated with tumor progression.