Effects of MAPK and NOTCH repression in colon cancer xenografts. (A) Schema and experimental schedule for xenografting, inhibitor treatment, and tumor analysis. (B) Immunofluorescence for FRA1 and NICD in SW480 and patient-derived (PDX1) xenografts. Vehicle-treated tumors (Ctrl) and AZD- or DBZ-treated tumors at indicated time points were analyzed. Arrowheads indicate tumor cells at the tumor edge, and arrows indicate tumor cells toward the tumor center. Areas above dotted lines are tumor necrosis. Bars, 50 µm. (C and D) Quantification of FRA1- and NICD-positive tumor cells in SW480 and PDX1 xenografts. Vehicle-treated tumors (Ctrl) and tumors at indicated time points during and after AZD (C) or DBZ (D) treatment were analyzed. Error bars are mean ± SD. *, P < 0.05; ***, P < 0.001 by t test; n.s., not significant; compared with Ctrl. n ≥ 3 independent biological replicates.