Expression of Cyclooxygenase-2 and p53 in Gastric Cancer and Precursor Lesions

Min, Sang Woon; Shon, Young Hae; Park, Chang Hwan; Lee, Wan Sik; Joo, Young Eun; Choi, Sung Kyu; Rew, Jong Sun; Park, Chang Soo; Kim, Sei Jong

Abstract

BACKGROUND/AIMS: The mechanism that controls cyclooxygenase-2 (COX-2) expression is not clear yet. Recently, it is reported that COX-2 expression is significantly high in the presence of mutated p53 genes. Thus, we investigated the expression of COX-2 and p53 in each stage of chronic gastritis, intestinal metaplasia, dysplasia, and gastric cancer, and studied their correlations. METHODS: The expressions of COX-2 and p53 in 128 local lesions were assessed immunohistochemically by using Micro-Probe System in a total of 101 patients. There were 23 chronic gastritis, 50 intestinal metaplasia, 34 dysplasia, and 21 intestinal type of gastric cancer. RESULTS: The expression of COX-2 was increased in 30.4% (7/23) of chronic gastritis, 68% (34/50) of intestinal metaplasia, 82.3% (28/34) of dysplasia, and 85.7% (18/21) of intestinal type gastric cancer. The expression of COX-2 was significantly increased as the disease progressed into gastric cancer (p<0.001). On the other hard, p53 was expressed positively in 38% (8/21) of gastric cancer, and 5.9% (2/34) of dysplasia. Although the difference was not statistically significant, expression of COX-2 seemed to be increased in gastric cancer with positive p53. CONCLUSIONS: COX-2, one of the major factors involved in the gastric carcinogenesis, may be involved in the early stage. Additionally, co-expression of COX-2 and p53 may have a role in promoting gastric carcinogenesis.