Expression of COX-2, IL-1β, TNF-α and IL-4 in epithelium of serrated adenoma, adenoma and hyperplastic polyp

Colon polyps and inflammatory process play the key role in neoplasia of colorectal cancer. In recent years there have been many publications on the malignancy of hyperplastic polyp (HP) which according to the WHO classification is a non-neoplastic polyp. The aim of this study is to determine the expression of inflammatory proteins COX-2, IL-1β, TNF-α and IL-4 in the epithelium of colorectal polyps.

In the study, 144 colorectal polyps were analyzed. The groups of HP, classical (A) and serrated adenomas (SA) and normal mucosa (control) according to histopathological studies were selected. Immunohistochemical examinations Rusing antibodies against COX-2, IL-1β, TNF-α and IL-4 were performed. The expression of analyzed protein was evaluated using modified Remmele-Stegner scale (0-16).

Statistical analysis revealed higher expression of TNF-α (16 ±3.87 vs. 1 ±5.06), IL-1β (12 ±4 vs 8 ±2.72), COX-2 (9 ±2.54 vs. 8 ±3.14) and IL-4 (12 ±3.45 vs. 4 ±3.35) in SA polyps compared to the control (p < 0.001). The HP had an increased level of expression of TNF-α (12 ±3.72 vs. 1 ±5.06, p < 0.005), COX-2 (8.5 ±1.97 vs. 8 ±3.14, p < 0.012) and IL-4 (12 ±3.46 vs. 4 ±3.35, p < 0.001). Significantly higher expression of IL-4 (12 ±2.32 vs. 4 ±3.35, p < 0.001) and IL-1β (16 ±4.32 vs. 8 ±2.72, p < 0.044) in A compared to the control were observed.

Expression of inflammatory factors differed between polyps. Inflammation accompanied the serrated structures which occur in polyps. The inflammatory process affects the development of colorectal polyps. The HP may predispose to malignancy.