Fig. 5

Collagen-enriched stroma in the recurrent tumors with increased tenascin-C and p-EGFR expression. a Hematoxylin and eosin (H&E) and trichrome staining of primary and recurrent tumors. b Quantification of percentage of collagen in primary, first recurrent, and second recurrent tumors. *p < 0.05, ***p < 0.001, comparisons represent primary versus first recurrence versus second recurrence. Values are shown as mean ± SEM. c Immunofluorescence staining of α-SMA, tenascin-C and S100A8 in primary and recurrent tumors. Nuclear staining is shown in blue (DAPI; and subsequent panels). d Quantification of S100A8+ MDSCs in recurrent tumors (n ≥ 5). **p < 0.005, comparisons represent primary versus first recurrence versus second recurrence. Values are shown as mean ± SEM. e p-EGFR expression levels in recurrent Wnt1/iR1 tumors through RPPA analysis. f Quantitative RT-PCR analysis of Areg normalized to GAPDH (n = 3). **p < 0.005. Values are shown as mean ± SEM. g Immunofluorescence staining of Areg in primary and recurrent tumors. Areg Amphiregulin, α-SMA alpha smooth muscle actin, DAPI 4′, 6-Diamidino-2-phenylindole, FGFR1 Fibroblast growth factor receptor 1, p-EGFR Phosphorylated epidermal growth factor receptor