Chicken Skin Mucosa Surrounding Adult Colorectal Adenomas is a Risk Factor for Carcinogenesis

Abstract

Transformation of normal mucosa to colorectal adenoma could occur over a span of 5 to 20 years, whereas transformation of colorectal adenoma to colorectal cancer could take an additional 5 to 15 years. This study aims to investigate whether chicken skin mucosa (CSM) surrounding adult colorectal adenomas may be a risk factor for carcinogenesis. Patients with colorectal mucosa, colorectal adenomas without CSM, or colorectal adenomas with CSM were enrolled in this study. Immunohistochemistry and enzyme-linked immunosorbent assays were used to determine the expression levels of proliferation markers (ki-67 and COX-2) and apoptosis factors (survivin and caspase-3) in tissues. The expression of ki-67 was significantly higher in colorectal adenomas with CSM compared with colorectal adenoma tissues (P < 0.01). Colorectal adenocarcinoma showed significantly higher levels of COX-2 protein compared with normal colorectal mucosa and colorectal adenoma tissues (P < 0.001). COX-2 expression was significantly higher in adenomas with CSM compared with normal colorectal mucosa (P < 0.001). Adenomas with CSM and adenocarcinomas exhibited significantly higher levels of survivin when compared with colorectal adenoma without CSM and normal tissues (P < 0.001). Although we found no significant difference in caspase-3 levels between adenocarcinomas and adenomas with CSM, caspase-3 expression was significantly lower in these tissues when compared with colorectal adenomas without CSM and normal mucosa (P < 0.001). The biological characteristics of colorectal adenomas with CSM were different from those of colorectal adenomas without CSM. Colorectal adenomas with CSM exhibited active cell proliferation and inhibition of apoptotic pathways, suggesting an increased risk of carcinogenesis in these adenomas.