Expression of cyclooxygenase-2 in human esophageal squamous cell carcinomas

AIM: To determine whether cyclooxygenase-2 (COX-2) was expressed in human esophageal squamous cell carcinoma. METHODS: Quantitative reverse transcription-polymerase chain reaction (RT-PCR), western blotting, immunohistoc-hemistry and immunofluorescence were used to assess the expression level of COX-2 in esophageal tissue. RESULTS: COX-2 mRNA levels were increased by >80-fold in esophageal squamous cell carcinoma when compared to adjacent noncancerous tissue. COX-2 protein was present in 21 of 30 cases of esophageal squamous cell carcinoma tissues, but was undetectable in noncancerous tissue. Immunohistochemistry was performed to directly show expression of COX-2 in tumor tissue. CONCLUSION: These results suggest that COX-2 may be an important factor for esophageal cancer and inhibition of COX-2 may be helpful for prevention and possibly treatment of this cancer.