Tumor-conditioned macrophages secrete migration-stimulating factor: A new marker for M2-polarization, influencing tumor cell motility

Department of Immunology and Inflammation, Clinical Institute Humanitas, Rozzano, Italy.
The Journal of Immunology (Impact Factor: 5.36). 07/2010; 185(1):642-52. DOI: 10.4049/jimmunol.1000413
Source: PubMed

ABSTRACT Tumor-associated macrophages (TAMs) are key orchestrators of the tumor microenvironment directly affecting neoplastic cell growth, neoangiogenesis, and extracellular matrix remodeling. In turn, the tumor milieu strongly influences maturation of TAMs and shapes several of their features. To address the early macrophage (M) differentiation phase in a malignant context, we mimicked a tumor microenvironment by in vitro coculturing human blood monocytes with conditioned media from different cancer cell lines. Only 2 out of 16 tumor cell lines induced M differentiation due to secreted M-CSF isoforms, including high molecular mass species. A global gene profiling of tumor-conditioned M was performed. Comparison with other datasets (polarized M1-M, M2-M, and TAMs isolated from human tumors) highlighted the upregulation of several genes also shared by TAM and M2-polarized M. The most expressed genes were selenoprotein 1, osteoactivin, osteopontin, and, interestingly, migration-stimulating factor (MSF), a poorly studied oncofoetal isoform of fibronectin. MSF (present in fetal/cancer epithelial and stromal cells but not in healthy tissues) was never identified in M. MSF production was confirmed by immunohistochemistry in human TAMs. MSF was induced by M-CSF, IL-4, and TGFbeta but not by proinflammatory stimuli. RNA and protein analysis clearly demonstrated that it is specifically associated with the M2 polarization of M. Tumor-conditioned M-derived MSFs strongly stimulated tumor cell migration, thus contributing to the motile phenotype of neoplastic cells. In conclusion, MSF is a new molecule associated with the M2 polarization of M and expressed by TAMs. Its biological function may contribute to M-mediated promotion of cancer cell invasion and metastasis.

Download full-text


Available from: Luca Zammataro, Jul 28, 2015
  • Source
    • "Fully differentiated and M1-and M2-polarized macrophages were obtained by culturing 10 6 monocytes/mL for 7 days at 37 ∘ C and 5% CO 2 with the same medium above described and replaced twice a week. M1 cells were polarized by stimulating overnight (O/N) with LPS (100 ng/mL) (InvivoGen) and IFNí µí»¾ (500 U/mL) (ImmunoTools), while M2 macrophages were polarized by stimulating O/N with IL-4 (20 ng/mL) (ImmunoTools) and IL-10 (50 ng/mL) (PeproTech) [22] [23]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Procalcitonin (PCT) is one of the best diagnostic and prognostic markers in clinical practice, widely used to evaluate the evolution of bacterial infections. Although it is mainly produced by thyroid, during sepsis almost all the peripheral tissues are involved in PCT production. Parenchymal cells have been suggested as the main source of PCT expression; however the contribution of macrophages is not clear yet. In response to environmental cues, tissue macrophages acquire distinct functional phenotypes, ranging from proinflammatory (M1) to anti-inflammatory (M2) phenotype. Macrophages at the fetal-maternal interface show immunosuppressive M2-like activities required for the maintenance of immunological homeostasis during pregnancy. This study aims to clarify the ability to synthesise PCT of fully differentiated (M0), polarized (M1/M2) macrophages and those cultured either in the presence of first trimester gravid serum (GS) or pregnancy hormones. We found out that M1 macrophages upregulate PCT expression following LPS stimulation compared to M0 and M2. The GS downregulates PCT expression in macrophages, skewing them towards an M2-like phenotype. This effect seems only partially mediated by the hormonal milieu. Our findings strengthen the key role of macrophages in counteracting inflammatory stimuli during pregnancy, suggesting PCT as a possible new marker of M1-like macrophages.
    Mediators of Inflammation 03/2014; 2014:248963. DOI:10.1155/2014/248963 · 3.24 Impact Factor
  • Source
    • "Macrophages play central roles in adaptive and innate immunity by antigen presentation and the production of a wide variety of cytokines. In tumors, tumor-associated macrophages (TAMs) infiltrate most solid human cancers and are associated with tumor progression and metastasis (Mantovani et al. 2002; Solinas et al. 2010; Sica and Mantovani 2012). The tumor-promoting functions of macrophages include the promotion of tumor cell migration, intravasation, epithelial–mesenchymal transition and the suppression of anti-tumor immunity. "
    [Show abstract] [Hide abstract]
    ABSTRACT: We previously demonstrated that Siglec-15, a member of the Siglec family of glycan-recognition proteins, is expressed on a subset of macrophages and preferentially recognizes the sialyl-Tn (sTn) antigen, a tumor-associated glycan structure. In this study, we report on the biological significance of the Siglec-15-mediated interaction between monocytes/macrophages and cancer cells. Siglec-15 is expressed on tumor-associated macrophages in various human tumor tissues. We further demonstrated that its expression is substantially elevated in macrophage-colony stimulating factor-induced M2-like macrophages, which produced more TGF-β in response to sTn-positive cells than to negative cells. We designed a co-culture model of THP-1 (human monocytic leukemia) cells and H157 (human lung carcinoma) cells mimicking the interaction between monocytes/macrophages and cancer cells that recapitulated the enhanced TGF-β production in Siglec-15 expressing THP-1 cells by the cellular interaction with sTn expressing H157 cells. The enhanced TGF-β production required direct interaction between the two cell lines through sialic acids. Siglec-15 associates with adaptor protein DAP12 at the binding determinant Lys(274) in the transmembrane domain, and transduces a signal to Syk tyrosine kinase. The enhanced TGF-β secretion was significantly attenuated by Syk inhibitor treatment of THP-1 cells, or by substitution of the Siglec-15 Lys(274) to Ala, which disrupts the molecular interaction between Siglec15 and DAP12. These findings indicate that Siglec-15 recognizes the tumoral sTn antigen and transduces a signal for enhanced TGF-β secretion in tumor associated macrophages, and further suggest that Siglec-15 on macrophages may contribute to tumor progression by the TGF-β-mediated modulation of intratumoral microenvironments.
    Glycobiology 10/2012; 23(2). DOI:10.1093/glycob/cws139 · 3.75 Impact Factor
  • Source
    • "The inhibitory effect of treatment with an anti-GPMNB antibody on melanoma tumor growth in vivo may be explained by the fact that it targets both TAMs in the tumor stroma and tumor cells. Furthermore, Solinas et al. (2010) also found in their microarray analysis that GPMNB is expressed in PCMI-Mφ(Solinas et al., 2010). Our data support the invasive signature of TAMs induced from MCMI-Mφ. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The presence of tumor-associated macrophages (TAMs) in melanomas is correlated with a poor clinical prognosis. However, there is limited information on the characteristics and biological activities of human TAMs in melanomas. In this study, we developed an in vitro method to differentiate human monocytes to macrophages using modified melanoma-conditioned medium (MCM). We demonstrate that factors from MCM-induced macrophages (MCMI-Mφ) express both M1-Mφ and M2-Mφ markers and inhibit melanoma-specific T-cell proliferation. Furthermore, microarray analyses reveal that the majority of genes up-regulated in MCMI-Mφ are associated with tumor invasion. The most strikingly up-regulated genes are CCL2 and MMP-9. Consistent with this, blockade of both CCL-2 and MMPs diminish MCMI-Mφ-induced melanoma invasion. Finally, we demonstrated that both MCMI-Mφ and in vivo TAMs express the pro-invasive, melanoma-associated gene, glycoprotein non-metastatic melanoma protein B. Our study provides a framework for understanding the mechanisms of cross-talk between TAMs and melanoma cells within the tumor microenvironment.
    Pigment Cell & Melanoma Research 04/2012; 25(4):493-505. DOI:10.1111/j.1755-148X.2012.01005.x · 5.64 Impact Factor
Show more