Abstract: Objectives:  To study the expression, clinical significance of COX-2 and 15-PGDH in esophageal squamous cell carcinoma and cancer cell strains. Methods : The expressions of COX-2 and 15-PGDH were determined with immunohistochemical (PV-9000) method in normal esophageal mucosa (n=35 patients), esophageal squamous cell carcinoma (n=35 patients), and esophageal cell strains (EC9706). The expression of mRNA of 15-PGDH was determined with RT-PCR method in normal esophageal mucosa and esophageal squamous cell carcinoma. Results:   The expression of COX-2 was significantly higher in esophageal squamous cell carcinoma than in normal tissue (P < 0.01). The expression of 15-PGDH and 15-PGDHmRNA were significantly lower in esophageal squamous cell carcinoma than in normal tissue (P < 0.05，P < 0.01).The expressions of COX-2 and 15-PGDH were significantly associated with invasive depth of carcinoma tissue and the status of lymph node metastasis (P<0.05). The expressions of COX-2 and 15-PGDH were not significantly associated with sex, age and tumor differentiation. A high expression of COX-2 and a low expression of 15-PGDH were observed in esophageal cell strains. Conclusions:  Compared to normal tissue, a higher expression of COX-2 and a lower expression of 15-PGDH were found in esophageal squamous cell carcinoma and cancer cell strains. COX-2 and 15-PGDH may play an important role in the occurrence and development of esophageal carcinoma.

Key words: Esophageal neoplasms, carcinoma, cell line, tumor, Cyclooxygenase-2, hydroxyprostaglandin dehydrogenases, immunohistochemistry, 逆转录聚合酶链反应