Figure 4.

Resident and BM-derived CAFs express distinct immune-related genes. Following BM transplantation, resident and BM-derived CAFs from mammary tumors and lungs bearing macrometastases of recipient mice were tested for the expression of 561 immunology-related genes using the NanoString nCounter gene expression panel. n = 2 mice in each group. (A) Heat map presentation of differentially expressed genes of resident versus BM-derived CAFs in primary tumors (left) and lungs bearing macrometastases (right). (B) Venn diagrams of the 40 most highly expressed genes in each cell population. (C) Hierarchical clustering of total expressed genes in resident and BM-derived CAFs from primary tumors and lungs bearing macrometastases. Scaling method: unit variance scaling; PCA method: single-value decomposition with imputation. (D–I) PDGFRα⁺-resident CAFs and PDGFRα⁻ BM-derived CAFs have distinct tumor-promoting functions. Resident CAFs (EpCAM⁻CD45⁻Col1α⁺PDGFRα⁺) and BM-derived CAFs (EpCAM⁻CD45⁻Col1α⁺PDGFRα⁻) were isolated from mammary tumors of PyMT;Col1α-YFP female mice, cultured, and injected in a Matrigel plug to FVB/n female mice. n = 4. Experiments were repeated twice. (D) Light and fluorescent microscopy of resident CAFs (left) and BM-derived CAFs (right) cultures preinjection. Bars, 30 µm. (E) Representative images of the plugs extracted 3 wk after injection. Bar, 5 mm. (F and H) Immunostaining of Meca32 (F) or F4/80 (H). 5 sections per plug were stained and 5 fields per section were analyzed for a total of 100 fields per cell type. Bars, 30 µm. (G and I) Quantification of staining presented in F and H performed with ImageJ software. Results are normalized to control (PBS-only plugs). Error bars represent SEM. ****, P < 0.0001 (G); **, P = 0.0041 (I); two-tailed Mann-Whitney test.