Arsenic trioxide-induced hela cell death is partially prevented by K+ channel blockers
Dong, D-Li.; Song, W-Hua.; Pei-Lin; Yang, B-Feng.
Yao Xue Xue Bao 40(7): 644-648
2005
ISSN/ISBN: 0513-4870 PMID: 16196273 Document Number: 585499
Aim To investigate the effects of K+ channel blockers on arsenic trioxide-induced HeLa cell death. Methods Viability of HeLa cells was assessed by mitochondrial dehydrogenase activity using colorimetric MTT assay and the voltage-dependent K+ currents were recorded by using patch-clamp technique. Results Exposure of As2O3 (5 mu mol . L-1) for 24 h caused marked HeLa cell death. The rest living cells after AS(2)O(3) 24 h-incubation showed significant increase of K+ currents densities. At +80 mV, the densities of K+ currents (61 +/- 18) pA/10 pF (n=8) in AS(2)O(3) 24 h-incubation group were significantly more than that in the control group (38 +/- 10) pA/10 pF (n=8, P<0.05). The HeLa cells were prevented partially from As2O3-induced cell death by co-application for 24 h with typical voltage-dependent K+ channel blockers, 4-aminopyridine (3 mmol . L-1) or tetraethylammonium (5 mmol . L (-1)). 4-Aminopyridine (3 mmol . L-1) or tetraethylammonium (5 mmol . L-1) did not show any toxic effects on HeLa cells. Conclusion Chronic treatment with As2O3 increased voltage-dependent K+ currents in HeLa cells and the cell death induced by As2O3 was reduced partially by voltage-dependent K+ channel blockers, 4-aminopyridine or tetraethylammonium.