Periostin Promotes Sarcoma Growth by Promoting Tumor-Associated Macrophage Migration and Differentiation

Figures

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  Figure 1.. POSTN expression is correlated with patient survival and expression of extracellular matrix proteins. A, Kaplan–Meier plot showing reduced survival for patients with sarcoma expressing high POSTN levels. B and C, Pathway analysis of patients with sarcoma showing high vs. low POSTN expression levels revealed increased expression of ECM-related elements in POSTN-high patients. D, Schematic representation of the sarcoma mouse models. E, Volcano plot of select differentially expressed genes in tumor cells sorted from the p53KOVgll3OE (positive log fold change) vs. p53KOCcne1OE (negative log fold change) mouse tumors. F, Heat map showing the most differentially expressed soluble factors in the ELISA array comparing p53KOVgll3OE vs. p53KOCcne1OE whole tumors. G, Expression of Postn mRNA in tumor cells, adjacent CAFs, and bone marrow–derived mesenchymal cells (CD45− PDGFRA+). Unless otherwise indicated, results are presented as mean ± SEM, and P values were derived from a two-tailed unpaired Student t test (*, P < 0.05). [Created in BioRender. Guarnerio, J. (2025) https://BioRender.com/fo00cpj.]

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  Figure 2.. Postn silencing reduces tumor growth in the p53KOVgll3OE mouse model. A, Western blot analysis of POSTN expression in murine Postn-WT and Postn-OE sarcoma cells (p53KOVgll3OE). B, Soft agar assays comparing Postn-WT and Postn-OE sarcoma cells (p53KOVgll3OE). Representative images of the analyzed spheroids (right) and spheroid area quantification (left) are shown. Each dot represents a quantified imaging area. C, Relative expression of Postn in FACS-sorted tumor cells upon Postn silencing through shRNAs (shPostn) in p53KOVgll3OE sarcoma cells. D, Tumor size at different time points, comparing Postn-WT (shSCR) and Postn-silenced (shPostn) sarcoma cells (p53KOVgll3OE). E, Weight of the tumor masses at the experimental endpoint, comparing tumors generated by Postn-WT (shSCR) and Postn-silenced (shPostn) sarcoma cells (p53KOVgll3OE). F, Heatmap of the top differentially expressed genes with absolute log2 fold change > 1. G, Top pathways enriched in shPostn vs. shSCR sarcoma cells (p53KOVgll3OE). No pathways were enriched in shSCR vs. shPostn tumor cells. Unless otherwise indicated, results are presented as mean ± SEM, and P values were derived from a two-tailed unpaired Student t test…

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  Figure 3.. Postn silencing in tumor cells shapes the sarcoma immune microenvironment. A, Flow cytometry analysis of CD45+ immune cells and different types of immune cells within the CD45+ population in the microenvironment of Postn-WT (shSCR) and Postn-silenced (shPostn) tumors (p53KOVgll3OE). Each dot represents one mouse. B, Subclustering of the mononuclear phagocyte compartment (macrophages, monocytes, and dendritic cells) from scRNA-seq. C, Proportions of the subclusters from B in individual shSCR or shPostn tumors (n = 5 mice in each group). D, Pathways enriched in mononuclear phagocytes from shPostn tumors (top) or from shSCR tumors (bottom). E, Relative expression of IFN-stimulated and proinflammatory genes in CD11b+ myeloid cells FACS-sorted from mouse tumors, generated by either Postn-WT (shSCR) or Postn-silenced (shPostn) sarcoma cells. Each dot represents one mouse. F, Flow cytometry analysis of CD45+ immune cells and different types of immune cells within the CD45+ population in the microenvironment of mice treated with POSTN-blocking antibody (anti-POSTN). Each dot represents one mouse. Unless otherwise indicated, results are presented as mean ± SEM, and P values were derived…

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  Figure 4.. Postn recruits bone marrow monocytes and promotes the accumulation of macrophages. A, Quantification of POSTN levels in the serum of sarcoma-bearing mice compared with healthy mice. Each dot represents one mouse. B, Quantification of POSTN levels in the bone marrow of sarcoma-bearing mice compared with healthy mice. Each dot represents one mouse. C, Transwell migration assays to measure the capability of bone marrow–derived monocytes to migrate toward recombinant POSTN protein after 16 hours of exposure or (D) in the presence of POSTN-neutralizing antibodies. E, Transwell migration assays to assess the capability of bone marrow–derived monocytes to migrate toward supernatant from sarcoma cells expressing wild-type (Postn-WT) or enhanced Postn levels (Postn-OE). F and G, Analysis of monocytes (Ly6C+F4/80− cells) and macrophages (Ly6C-F4/80+ cells) at two different time points (days 4 and 6) in culture with recombinant POSTN protein. Unless otherwise indicated, results are presented as mean ± SEM, and P values are derived from a two-tailed unpaired Student t test (*, P < 0.05; **, P < 0.01; ***, P < 0.001). For C–G, each dot represents BMDM derived from a single mouse (n = 4…