Fig. 3.

Biofilms are associated with changes in E-cadherin, IL-6, and Stat3 activation. (A and B) Evaluation of E-cadherin and IL-6 by immunofluorescence (green) and activated Stat3 (pStat3, brown nuclei) by immunohistochemistry. Blue, nuclear DAPI counterstain; red, smooth muscle antigen. [Scale bars, 100 μm (E-cadherin) and 50 μm (IL-6, pStat3).] (A) Normal colonic tissues associated with a biofilm from patients with CRC (Left), obtained during surgery, display diminished crypt colonic epithelial cell E-cadherin (white arrows, n = 7 biofilm-positive or -negative tissues) and increased epithelial cell IL-6 (white arrows, n = 13 biofilm-positive or -negative tissues), as well as epithelial cell pStat3 (black arrows, n = 16 biofilm-positive and n = 12 biofilm-negative tissues). Normal colonic tissues without a biofilm from patients with CRC (Right), likewise obtained during surgery, display intact E-cadherin. IL-6 and pStat3 are detected in the lamina propria. (B) Biofilm-positive colonoscopy biopsies from subjects without CRC (Left) display epithelial cell E-cadherin redistribution (Inset) and increased tissue IL-6, whereas biofilm-negative colonoscopy biopsies (Right) display intact E-cadherin and modest lamina propria IL-6 expression. pStat3 is observed in the lamina propria immune cells in both biofilm-positive and biofilm-negative colonoscopy biopsies. (C–F) Quantification of crypt cell E-cadherin (fluorescence intensity), epithelial cell IL-6 [fluorescence intensity and isolated colonic epithelial cells (CEC) by ELISA], and epithelial cell pStat3 (immunohistochemistry) from A are shown in C–F, respectively. Data displayed as bar and whisker graphs, where line designates the median, boxes the 25/75th percentile, and whiskers the 95th percentile (C and D) or mean ± SD (E and F). Details in SI Appendix, Materials and Methods. SI Appendix, Figs. S10 and S11 show additional E-cadherin, IL-6, and pStat3 quantification from A and B.