Figure 2.

Chemotherapy induces a specific increase in macrophage infiltration in breast tumors. (A) Macrophages accumulate in tumors after Taxol treatment. Representative images of orthotopic tumors stained for the macrophage marker Iba1 7 d after vehicle or Taxol treatment. Bars, 100 μm. (B) Quantitation of intratumoral Iba1⁺ cells in tumors of vehicle- and Taxol-treated mice via image analysis. n = 12 vehicle, 9 Taxol; (***) P < 0.0001. All data in B–F are from whole tumors isolated 7 d after vehicle or Taxol treatment. (C,D) qRT–PCR from whole-tumor lysates for transcripts of CD68 (macrophages) and CD45 (all leukocytes) 7 d after vehicle or Taxol treatment (n = 7–8 tumors); (*) P < 0.05. (E) Quantitation by image analysis of the percentage of CD45⁺Iba1⁻ cells of total DAPI⁺ cells in tumors after treatment with vehicle or Taxol (n = 6 mice per group). (F) Representative images of tumor sections from mice injected with the cathepsin ABP after vehicle or Taxol treatment and costained with the macrophage marker Iba1. (G) Macrophage numbers increase in breast cancer patients following neoadjuvant chemotherapy. Representative images of matched samples pre- and post-treatment from patients 2, 3, 5, and 6 stained with CD68 or a pan-cytokeratin (CK) antibody to visualize tumor cells. Positively stained cells are labeled in brown. Rare CD68⁺ cells in the pretreatment biopsies are indicated by white arrowheads. Patient information can be found in Supplemental Table S1. Bars: F,G, 50 μm.