Abstract:

Objective To investigate the inhibitory effect of nimesulide and aspirin on esophageal squamous cell carcinoma(ESCC) cell lines with or without cyclooxygenase-2 expression.
Methods The human ESCC cell lines EC109 and TE-1 were used in this study. Cox-2 expression was detected by Western blotting. After 72 hours treatment with nimesulide and aspirin, the cell growth inhibition was determined by MTT assay, the cell cycle arrest and apoptosis detected by flow cytometry.
Results Cox-2 protein expression was observed in EC109, but not in TE-1. Nimesulide suppressed proliferation of EC109 from 0.05 mmol/L to 0.4 mmol/L in a dose-dependent manner, while only 0.4 mmol/L nimesulide showed this effect in TE-1. Nimesulide exerted cell cycle arrest in the G₀/G₁ phase with induction of apoptosis, but had no effect on TE-1. Aspirin suppressed proliferation of EC109 as well as TE-1 in a dose-dependent manner and promoted apoptosis in both cell lines.
Conclusion The inhibitory effect on ESCC cell lines may be influenced by COX-2 expression for nimesulide, but not for aspirin. Non-selective COX-2 inhibitor may exert inhibitory effect on tumor proliferation via COX-2 independent pathway.

Key words: cyclooxygenase-2, esophageal squamous cell carcinoma, proliferation, apoptosis