Table of Contents
Journal of Biophysics
Volume 2012 (2012), Article ID 921653, 6 pages
http://dx.doi.org/10.1155/2012/921653
Research Article

Redox Regulation of Calcium Signaling in Cancer Cells by Ascorbic Acid Involving the Mitochondrial Electron Transport Chain

Department of Biophysics, Belarusian State University, Nezavisimosti Avenue 4, 220030 Minsk, Belarus

Received 29 August 2012; Revised 29 October 2012; Accepted 29 October 2012

Academic Editor: Eaton Edward Lattman

Copyright © 2012 Grigory G. Martinovich et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Previously, we have reported that ascorbic acid regulates calcium signaling in human larynx carcinoma HEp-2 cells. To evaluate the precise mechanism of Ca2+ release by ascorbic acid, the effects of specific inhibitors of the electron transport chain components on mitochondrial reactive oxygen species (ROS) production and Ca2+ mobilization in HEp-2 cells were investigated. It was revealed that the mitochondrial complex III inhibitor (antimycin A) amplifies ascorbate-induced Ca2+ release from intracellular stores. The mitochondrial complex I inhibitor (rotenone) decreases Ca2+ release from intracellular stores in HEp-2 cells caused by ascorbic acid and antimycin A. In the presence of rotenone, antimycin A stimulates ROS production by mitochondria. Ascorbate-induced Ca2+ release in HEp-2 cells is shown to be unaffected by catalase. The results obtained suggest that Ca2+ release in HEp-2 cells caused by ascorbic acid is associated with induced mitochondrial ROS production. The data obtained are in line with the concept of redox signaling that explains oxidant action by compartmentalization of ROS production and oxidant targets.