Arsenic trioxide (As{sub 2}O{sub 3}) induced calcium signals and cytotoxicity in two human cell lines: SY-5Y neuroblastoma and 293 embryonic kidney (HEK)
- Institut fuer Physiologie, Universitaetsklinikum, Universitaet Duisburg Essen, Hufelandstrasse 55, 45122 Essen (Germany)
Arsenic trioxide (As{sub 2}O{sub 3}) has anticancer properties; however, its use also leads to neuro-, hepato- or nephro-toxicity, and therefore, it is important to understand the mechanism of As{sub 2}O{sub 3} toxicity. We studied As{sub 2}O{sub 3} influence on intracellular calcium ([Ca{sup 2+}]{sub i}) homeostasis of human neuroblastoma SY-5Y and embryonic kidney cells (HEK 293).We also relate the As{sub 2}O{sub 3} induced [Ca{sup 2+}]{sub i} modifications with cytotoxicity. We used Ca{sup 2+} sensitive dyes (fluo-4 and rhod-2) combined with laser scanning microscopy or fluorescence activated cell sorting to measure Ca{sup 2+} changes during the application of As{sub 2}O{sub 3} and we approach evaluation of cytotoxicity. As{sub 2}O{sub 3} (1 {mu}M) increased [Ca{sup 2+}]{sub i} in SY-5Y and HEK 293 cells. Three forms of [Ca{sup 2+}]{sub i}-elevations were found: (1) steady-state increases (2) transient [Ca{sup 2+}]{sub i}-elevations and (3) Ca{sup 2+}-spikes. [Ca{sup 2+}]{sub i} modifications were independent from extracellular Ca{sup 2+} but dependent on internal calcium stores. The effect was not reversible. Inositol triphosphate (IP{sub 3}) and ryanodine (Ry) receptors are involved in regulation of signals induced by As{sub 2}O{sub 3}. 2-APB and dantrolene significantly reduced the [Ca{sup 2+}]{sub i}-rise (p < 0.001, t-test) but did not completely abolish [Ca{sup 2+}]{sub i}-elevation or spiking. This indicates that other Ca{sup 2+} regulating mechanisms are involved. In cytotoxicity tests As{sub 2}O{sub 3} significantly reduced cell viability in both cell types. Staining with Hoechst 33342 showed occurrence of apoptosis and DNA damage. Our data suggest that [Ca{sup 2+}]{sub i} is an important messenger in As{sub 2}O{sub 3} induced cell death.
- OSTI ID:
- 20976921
- Journal Information:
- Toxicology and Applied Pharmacology, Vol. 220, Issue 3; Other Information: DOI: 10.1016/j.taap.2007.01.022; PII: S0041-008X(07)00054-3; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0041-008X
- Country of Publication:
- United States
- Language:
- English
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