ABSTRACT
Aim To investigate the roles of chloride channels in the apoptosis and apoptotic volume de-crease (AVD)induced by adriamycin in nasopharyn-geal carcinoma CNE-2Z cells.Methods Apoptotic rates were detected by flow cytometry,and the volume changes were measured by the time-lapse live cell ima-ging technique.The patch clamp technique was used to record whole-cell chloride currents.Results Adria-mycin induced apoptosis of CNE-2Z cells.An early ap-optotic volume decrease was observed in the cell trea-ted with adriamycin.The cell volume was decreased by about 10% in 2 h.Adriamycin activated a chloride current which showed outward rectification.The chlo-ride channel blocker 5-nitro-2-(3-phenylpropylamino)-benzoate (NPPB ) could inhibit the adriamycin-in-duced chloride currents,apoptosis and prevent cell shrinkage.Conclusions Our findings suggest that ad-riamycin causes cell apoptosis by activation of chloride channels.Chloride channels may be involved in the apoptosis and apoptotic volume decrease induced by adriamycin in CNE-2Z cells.
ABSTRACT
Aim To investigate the effect of gelsemium alkaloids on chloride channels and cell volume in he-patic carcinoma cells. Methods The time-lapse live cell imaging and whole-cell patch clamp techniques were used respectively to detect the volume changes and currents induced by gelsemium alkaloids in HepG2 cells. Results It was found that the cell volume was decreased by (12. 48 ± 2. 2) % (P<0. 01) when ex-posed to gelsemium alkaloids for 50 min and this phe-nomenon could be inhibited by the chloride channel blocker tamoxifen. It was shown by whole-cell patch clamping that a chloride current could be evoked by extracellular application of gelsemium alkaloids ( 2μmol·L-1 ) . The current was outward-rectified with-out obvious voltage- and time-dependent inactivation. The reversal potential of the current was ( -3. 21 ± 0. 67) mV ,which was close to the equilibrium poten-tial of chloride. The extracellular application of the chloride blockers, tamoxifen and 5-notro-2-(3-phenyl-propylamino)benzoic acid (NPPB), and 47% hyper-tonic solution inhibited the current significantly ( P <0. 01 ) . Conclusion Gelsemium alkaloids could acti-vate chloride channels and induce a volume decrease ( named apoptotic volume decrease, AVD) , and these effect could be inhibited by chloride channel blockers. The results suggest that the chloride channel can be one of the targets of gelsemium alkaloids in their anti-cancer action.