Abstract: Abstract Objective: To investigate the roles of chloride channels in apoptotic volume decrease (AVD) and apoptosis in nasopharyngeal carcinoma cells (CNE-2Z). Methods: The changes of cell volume were monitored and analyzed by the time-lapse imaging technique. Cell apoptotic rates were measured by using nuclear staining analysis by Hoechst 33258. Results：The results showed that 5-Fu (100?mol/L) induced an early cell volume decrease just in a few minutes. The cell volume was decreased to 88.2% of the control volume in 120 min. The apoptotic rate induced by 5-Fu was 49.2% 48 h after treatments. Chloride channel blocker 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) prevented appearance of 5-Fu-induced cell shrinkage and apoptosis by 79.1% and 74.9%, respectively. Conclusion: Chloride channel blockers could inhibit 5-Fu-induced apoptotic cell volume decrease and apoptosis. The results suggest that chloride channels may contribute to 5-Fu-induced apoptosis by activation of chloride channels and inducing apoptotic volume decrease in CNE-2Z cells. The activation of chloride channels play an important role in the anti-tumour action of 5-Fu.

Key words: 5-Fluorouracil, nasopharyngeal neoplasms, apoptotic volume decrease, chloride channel, apoptosis