Analysis of Cytotoxicity of Anticancer Drugs

Apoptosis, induced in cancer cells by antitumor agents such as doxorubicin, dactinomycin, and the platinum drugs, is characterized by impaired respiration, decreased ATP, and activated caspase. To investigate the sensitivity of malignant cells to a variety of drug agents, quantitative measures of cytotoxicity under treatment of those drugs are employed. The mitochondrial oxygen consumptions are monitored by analyzing the phosphorescence decay rate of a palladium phosphor. Simultaneously, cellular ATP contents are detected through a bioluminescence system, and intracellular caspase activation measured by adopting the fluorogenic substrate. Comparing the ways in which respiration, ATP level, and caspase activity vary with time points up differences between the mechanisms of actions of various drugs, which finally result in mitochondrial dysfunction and cell apoptosis. These results become very useful in choosing the most effective drug for a particular clinical application.