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  2. Scavenger receptor MARCO contributes to macrophage phagocytosis and clearance of tumor cells

Scavenger receptor MARCO contributes to macrophage phagocytosis and clearance of tumor cells

  • Exp Cell Res. 2021 Nov 15;408(2):112862. doi: 10.1016/j.yexcr.2021.112862.
Qianqian Xing 1 Youxin Feng 2 Haimei Sun 3 Shu Yang 4 Tingyi Sun 5 Xiaoxia Guo 6 Fengqing Ji 7 Bo Wu 8 Deshan Zhou 9
Affiliations

Affiliations

  • 1 Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, China; Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Beijing, China; Cancer Institute of Capital Medical University, Beijing, China. Electronic address: [email protected].
  • 2 Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, China; Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Beijing, China; Cancer Institute of Capital Medical University, Beijing, China. Electronic address: [email protected].
  • 3 Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, China; Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Beijing, China; Cancer Institute of Capital Medical University, Beijing, China. Electronic address: [email protected].
  • 4 Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, China; Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Beijing, China; Cancer Institute of Capital Medical University, Beijing, China. Electronic address: [email protected].
  • 5 Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, China; Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Beijing, China; Cancer Institute of Capital Medical University, Beijing, China. Electronic address: [email protected].
  • 6 Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, China; Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Beijing, China; Cancer Institute of Capital Medical University, Beijing, China. Electronic address: [email protected].
  • 7 Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, China; Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Beijing, China; Cancer Institute of Capital Medical University, Beijing, China. Electronic address: [email protected].
  • 8 Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, China; Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Beijing, China; Cancer Institute of Capital Medical University, Beijing, China. Electronic address: [email protected].
  • 9 Department of Histology and Embryology, School of Basic Medical Sciences, Capital Medical University, Beijing, China; Beijing Key Laboratory of Cancer Invasion and Metastasis Research, Beijing, China; Cancer Institute of Capital Medical University, Beijing, China. Electronic address: [email protected].
Abstract

Macrophage receptor with collagenous structure (MARCO) is a member of the class A scavenger receptor family which is expressed on the cell surface of macrophages. It is well known that MARCO avidly binds to unopsonized pathogens, leading to its ingestion by macrophages. However, the role of MARCO in the recognition and phagocytosis of tumor cells by macrophages remains poorly understood. In this study, we used lentiviral technology to knockdown and overexpress MARCO and investigated the ability of macrophages to phagocytose tumor cells. Our results showed that MARCO expression was correlated with the ability of macrophages to carry on phagocytosis. MARCO knockdown led to significant decreases in the number of engulfment pseudopodia of macrophages and inhibition of the phagocytosis of tumor cells. On the other hand, MARCO overexpression elevated activity of Syk, PI3K and Rac1 in macrophages, which led to changes in macrophage morphology and enhanced phagocytosis by promoting formation of stress fibers and pseudopodia. By Co-IP analysis we showed that MARCO directly binds to the β5 Integrin of SL4 tumor cells. In summary, these results demonstrated the important role for MARCO in demonstrated tumor cells uptake and clearance by macrophages.

Keywords

Cytoskeleton; Macrophage receptor with collagenous structure (MARCO); Macrophages; PI3K; Phagocytosis; SYK.

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