Colonic NFs were established based on previously published protocols.
20 (
link),
27 (
link),
28 (
link) To obtain the tissue, during en bloc resection of specimens after colorectal ESD, normal mucosa was excised and washed in PBS with 1%
antibiotic‐antimycotic (Thermo Fisher Scientific, Waltham, MA, USA). Dulbecco's Modified Eagle Medium (DMEM)/Ham's F‐12 with L‐Glutamine and Phenol Red (Thermo Fisher Scientific) plus 1%
antibiotic‐antimycotic and 20% fetal bovine serum (FBS; Cytiva, Tokyo, Japan) was used as the medium. As the demarcation between the tumor and non‐tumor regions of colorectal tumors is visibly discernible through the naked eye or endoscopic observation, we collected normal mucosa specifically from areas identified as tumor‐free by visual assessment. NFs were subjected to fluorescent immunostaining using
Image‐iT Fixation/Permeabilization Kit (Thermo Fisher Scientific) and observed using a confocal laser microscope (C2si; Nikon Corporation, Tokyo, Japan). Anti‐α‐smooth muscle (
αSMA; 14‐9760‐80; dilution 1:1000; Thermo Fisher Scientific) and
anti‐E‐cadherin (610181; dilution 1:1000; Becton, Dickinson and Company, Franklin Lakes, NJ, USA) were used as primary antibodies, and Donkey anti‐Mouse IgG (H + L) Highly Cross‐Adsorbed Secondary Antibody, Alexa Fluor™ 488 (A‐21202, dilution 1:2000; Thermo Fisher Scientific) was used as a secondary antibody.
Inomata Y., Kuroha M., Shimoyama Y., Naito T., Moroi R., Shiga H., Kakuta Y., Karasawa H., Onuma S., Kinouchi Y, & Masamune A. (2024). Dickkopf 1 is expressed in normal fibroblasts during early stages of colorectal tumorigenesis. Cancer Medicine, 13(2), e6992.