To explore the tumor-stromal relationship in esophageal neoplasia, we examined methylation of COX-2 (PTGS2), a gene etiologically associated with the development of gastrointestinal cancers, in adjacent foci of epithelium, subepithelial lymphocytes and non-lymphocytic stromal cells found in sections of normal squamous epithelium, squamous dysplasia and invasive esophageal squamous cell carcinoma.
Moreover, low expression of COX-2 has been reported in a subset of gastrointestinal cancers due to COX-2 methylation, indicating that these patients could be less responsive to treatment by specific COX-2 inhibitors.
In summary, we have showed that levels of COX-2 are increased in both TCC and RCC derived from urinary tract epithelium as well as gastrointestinal cancer.
We investigated messenger RNA expression of the COX-1 and COX-2 genes in the gastrointestinal cancer cell lines MKN28, MKN45, KATO III CACO-2, DLD-1 and LoVo.