Mitochondria play central roles in cell life as a source of energy and in cell death by inducing apoptosis. Many important functions of mitochondria change in cancer, and these organelles can be a target of chemotherapy. The widely used anticancer drug doxorubicin (DOX) causes cell death, inhibition of cell cycle/proliferation and mitochondrial impairment. However, the mechanism of such impairment is not completely understood. In our study we used confocal and two-photon fluorescence imaging together with enzymatic and respirometric analysis to study short- and long-term effects of doxorubicin on mitochondria in various human carcinoma cells. We show that short-term (< 30 min) effects include i) rapid changes in mitochondrial redox potentials towards a more oxidized state (flavoproteins and NADH), ii) mitochondrial depolarization, iii) elevated matrix calcium levels, and iv) mitochondrial ROS production, demonstrating a complex pattern of mitochondrial alterations. Significant inhibition of mitochondrial endogenous and uncoupled respiration, ATP depletion and changes in the activities of marker enzymes were observed after 48 h of DOX treatment (long-term effects) associated with cell cycle arrest and death. © 2011 Elsevier B.V.
Kuznetsov, A. V., Margreiter, R., Amberger, A., Saks, V., & Grimm, M. (2011). Changes in mitochondrial redox state, membrane potential and calcium precede mitochondrial dysfunction in doxorubicin-induced cell death. Biochimica et Biophysica Acta - Molecular Cell Research, 1813(6), 1144–1152. https://doi.org/10.1016/j.bbamcr.2011.03.002