Figure 4.

Regressed α3β1-deficient tumors have fewer macrophages. K14CreERT:α3flx/flx mice were subjected to two-step tumorigenesis then treated with 4OHT or vehicle, as in Figure 1e. (a) Cryosections stained with anti-CD11b (red); t, tumor cells; s, stroma; dashed line, tumor-stroma boundary; scale bar, 200 μm. (b, c) Graphs show (b) CD11b+ area or (c) F4/80+ area relative to total area in 4OHT-treated tumors, normalized to vehicle (dotted line). (d) % F4/80-positive cells that are TUNEL-positive at treatment day 7. (b-d) n≥8 papillomas per group, per timepoint. Data are mean +/− s.e.m.; two-tailed t-tests; *P<0.05. (e) Representative tumor 7-days post-4OHT treatment, co-stained with F4/80 (red) and TUNEL (green); box in left panel is enlarged in right panel. Arrowheads, TUNEL-positive macrophages; t, tumor cells; s, stroma; dashed line, tumor-stroma boundary; scale bars, 50 μm.