Figure 3.

M2 macrophages accumulate adjacent to the biopsy wound and interface with nearby BC cells

(A) Representative images of 20-day post-biopsy, stage I, ER⁺ breast tumor, immunofluorescently stained for CD163 and CD206 M2-like macrophages (white) and CK (red) and counterstained with DAPI (blue). The center hollow indicates the biopsy wound (BW). A high-power image corresponding to the yellow square displays the proximity of M2φ to cancer cells. H&E images show the corresponding areas.

(B) Paired line plot of the proportion of cells in tumor stroma adjacent to (<400 μm) and distant from (>3 mm away) the biopsy wound positive for CD163⁺/CD206⁺ in 14 invasive ductal carcinomas. p values were calculated using the paired t test.

(C) Spatiotemporal mapping of CD163⁺/CD206⁺ M2φ adjacent to and distant from the biopsy wound over various biopsy-to-surgery intervals.

(D) Representative images of 7-day post-biopsy or unbiopsied Py230 tumors, immunohistochemically stained for F4/80 and CD206 (brown) and counterstained with hematoxylin (blue). Yellow squares indicate the areas corresponding to the high-power images. The center oval of biopsied tumor images indicates the biopsy wound (BW). Graphs summarize the densities of F4/80⁺ or CD206⁺ normalized by nucleus count per field of view at 40× magnification. The data are shown as standard boxplots; p values were calculated using Wilcoxon test (n = 10).

(E) (Upper) Schematic illustration of experimental design for adoptive transfer of Mφ^DsRed. (Lower) Fluorescent microscopic images of 1-day post-biopsy Py230 tumors in mice that received Mφ^DsRed adoptive transfer at the time of biopsy (n = 6). The whole tumor and corresponding high-power images with the accumulation of Mφ^DsRed (red) around the biopsy wound (center hollow circle) are shown. The slide was counterstained with DAPI (blue). BW, biopsy wound.

(F) Immunoprofile of Mφ isolated from Py230 tumors before or at various times after biopsy. Tumor biopsy reduces the proportion of M1φ (MHCII^high) and increases the proportion of M2φ (MHCII^low) and the ratio of M2φ to M1φ in CD45⁺ cells in the tumor. The data are shown as standard boxplots; p values were calculated using one-way ANOVA, relative to day 0 (n = 7–8).

(G and H) Representative images of 7-day post-biopsy Py230 tumors (G) and 25-day post-biopsy ER⁺ clinical BC (H) adjacent to biopsy wound, immunofluorescently stained for CK (red), E-cadherin (green), and CD206 (white), and counterstained with DAPI (blue). The yellow dotted lines indicate the border of distinct zones outside the biopsy wound (BW).