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Updated: Jul 3, 2026
Quantifying Antibody-Dependent Cellular Cytotoxicity in a Tumor Spheroid Model: Application for Drug Discovery
Published on: April 26, 2024
Quantitative measure of cytotoxicity of anticancer drugs and other agents
Zhimin Tao1, Eyone Jones, Jerry Goodisman
1Department of Pediatrics, State University of New York, Upstate Medical University, Syracuse, NY 13210, USA.
Abstract:
Many anticancer drugs act on cancer cells to promote apoptosis, which includes impairment of cellular respiration (mitochondrial O(2) consumption). Other agents also inhibit cellular respiration, sometimes irreversibly. To investigate the sensitivity of cancer cells to cytotoxins, including anticancer drugs, we compare the profiles of cellular O(2) consumption in the absence and presence of these agents. Oxygen measurements are made at 37 degrees C, using glucose as a substrate, with [O(2)] obtained from the phosphorescence decay rate of a palladium phosphor. The rate of respiration k is defined as -d[O(2)]/dt in a sealed container. Different toxins produce different profiles of impaired respiration, implying different mechanisms for the drug-induced mitochondrial dysfunction. The decrease in the average value of k over a fixed time period, I, is proposed as a characteristic value to assess mitochondrial injury. The value of I depends on the nature of the toxin, its concentration, and the exposure time as well as on the cell type. Results for several cell types and 10 cytotoxins are presented here.
Insights
This study introduces a new method to measure how cytotoxins, including anticancer drugs, affect cancer cell respiration. This approach helps understand drug-induced mitochondrial dysfunction and cell death mechanisms.
Area of Science:
- Biochemistry
- Cell Biology
- Pharmacology
Background:
- Anticancer drugs often induce apoptosis by impairing cellular respiration, specifically mitochondrial oxygen consumption.
- Understanding the mechanisms of drug-induced mitochondrial dysfunction is crucial for developing effective cancer therapies.
Purpose of the Study:
- To investigate the sensitivity of cancer cells to various cytotoxins by comparing cellular oxygen consumption profiles.
- To characterize drug-induced mitochondrial dysfunction and explore its link to apoptosis.
Main Methods:
- Oxygen consumption measurements were performed at 37°C using glucose as a substrate.
- Oxygen levels were determined using the phosphorescence decay rate of a palladium phosphor in sealed containers.
- The rate of respiration (k) was defined as the negative change in oxygen concentration over time (-d[O(2)]/dt).
Main Results:
- Different cytotoxins exhibited distinct profiles of impaired respiration, suggesting varied mechanisms of mitochondrial dysfunction.
- A characteristic value 'I' (decrease in average respiration rate over time) was proposed to quantify mitochondrial injury.
- The value 'I' was found to be dependent on toxin type, concentration, exposure time, and cell type.
Conclusions:
- The study presents a novel method to assess mitochondrial injury caused by cytotoxins.
- The distinct respiration profiles indicate diverse mechanisms underlying drug-induced mitochondrial dysfunction.
- The proposed metric 'I' offers a valuable tool for evaluating the impact of cytotoxins on cellular respiration and mitochondrial health.
