Identification of immunohistochemical markers for colonic subepithelial and pericryptal myofibroblasts and investigation of their expressions in the neoplastic process

Colonic subepithelial and pericryptal myofibroblasts are located just beneath the epithelium in the colonic lamina propria whom are -SMA positive mesenchymal cells that play a role in many processes such as wound healing, epithelial growth, fibrosis, immuno-tolerance, inflammation and tumor invasion. In addition to subepithelial myofibroblasts, there are other mesenchymal cells (eg, pericytes) in the colonic lamına propria which are stained positive with -SMA. The aim of this thesis is find a specific biomarker for colonic subepithelial and pericryptal myofibroblasts. Twenty patients who underwent colectomy for adenocarcinoma in Hacettepe University School of Medicine in 2019 were included in this study. Tissue microarray was prepared by sampling two separate foci from paraffin blocks representing the normal colon mucosa of each case. Immunohistochemical studies were performed using -SMA, Desmin, ZEB1, TMEM119, AOC3, PR2D3, MYH11, CD146, CD56 antibodies on serial sections. Expression of TMEM119, AOC3, and MYH11 were evaluated in 28 colorectal adenocarcinoma cases in two different tissue microarrays. In this study, we demonstrated that colonic subepithelial and pericryptal myofibroblasts were positive for TMEM119 for the first time in the literature. Presence of ZEB-1 expression in myofibroblasts supports the EMT event. In colorectal cancers loss of myofibroblastic markers in stroma were also demonstrated.