Fig. 2.

Macrophage-specific Act1 knockdown resulted in adenoma-adenocarcinoma transition in Apc^Min/+ mice by promoting TAMs recruitment. (A) The effect of macrophage-specific Act1 knockdown on tumor development. (a) Methylene blue staining of large and many polyps of the small intestine in AA mice compared with Apc^Min/+ mice at 15^th week. Tumor number (b) and tumor size (c) of the small intestine and colorectum in Apc^Min/+ mice and AA mice at the 9^th, 12^th, and 15^th week. Scale bar, 1 mm. (B) Representative H&E staining of intestinal tumors of Apc^Min/+ mice and AA mice at the 9^th, 12^th, and 15^th week. The dotted line box highlights adenocarcinoma transition in AA mice at different week points. Scale bar, 100 μm. (C) Survival analysis of Apc^Min/+ (n = 40) and AA (n = 30) mice. The log-rank test showed a statistically significant increase in the hazard of death in AA compared with Apc^Min/+ mice (p < 0.0001). (D) Immunohistochemical staining and statistical analysis for CA19-9 (a) and nuclear translocation of β-catenin (b) in intestinal tumors from Apc^Min/+ and AA mice at 9^th, 12^th and15^th week. Scale bar, 100 μm. (E) Representative immunohistochemistry images of Ki67, F4/80⁺ macrophages, and CD8⁺ T cells in the colon of Apc^Min/+ mice and AA mice at the 15^th week. (a). Scale bar, 50 μm. Quantification of Ki67 (b), F4/80⁺ macrophages (c), and CD8⁺ T cells (d). (F) The effect of macrophage depletion (CL: clodronate liposomes) on tumor development in AA mice. (a) Representative H&E staining of tumors in Apc^Min/+ and AA mice at the 15^th week. Scale bar, 100 μm. (b) Representative gross specimens from the indicated genotype analyzed at the 15^th week and quantification of tumor number and volume. (G) Immunohistochemical staining and quantification for F4/80⁺ macrophages and CD8⁺ T cells in tumors after macrophage depletion, Scale bar, 50 μm. Significant difference between the groups, *p < 0.05, ** p < 0.01, *** p < 0.001, and **** p < 0.0001 (Student t test). CL: clodronate liposomes