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Updated: Aug 9, 2026
Assessing Specificity of Anticancer Drugs In Vitro
Published on: March 23, 2016
Microplate screening for apoptosis with antibody to single-stranded DNA distinguishes anticancer drugs from toxic
Oskar S Frankfurt1, Awtar Krishan
1Radiation Oncology Department (R-71), University of Miami Medical School, 1550 NW 10th Ave., PAP Bldg. Room 128, Miami, FL 33136, USA. apostain@bellsouth.net
Abstract:
The effect of anticancer drugs and toxic compounds on cultures of human leukemic cells was evaluated by an enzyme-linked immunosorbent assay (Apoptosis ELISA) that uses a monoclonal antibody against single-stranded DNA to quantitate the apoptotic cells. The concentrations of 13 anticancer drugs, which increased Apoptosis ELISA absorbance, were close to the cytotoxic concentrations determined by the long-term cell survival assay. Short-term tetrazolium-based microculture tetrazolium (MTT) assay was significantly less sensitive than the Apoptosis ELISA and the cell survival assay for all anticancer drugs. For 6 drugs, cytotoxic concentrations measured by the MTT assay were at least 1 log higher than the concentrations inducing apoptosis. Importantly, in contrast to the anticancer drugs, 14 toxic chemicals did not increase the Apoptosis ELISA absorbance at cytotoxic concentrations. The difference in apoptosis induction by the anticancer drugs and the toxic chemicals was especially large in cultures treated with drug concentrations 2-fold higher than the IC(50) dose. Although all of the anticancer drugs tested induced intense ELISA reaction (mean absorbance 2.0), all toxic chemicals tested did not induce apoptosis. The Apoptosis ELISA assay could have useful applications in drug development as it can distinguish between clinically useful anticancer drugs and toxic compounds, has sensitivity similar to that of the long-term cell survival assay, and provides insight into the mechanism of drug cytotoxicity by differentiating between compounds killing cells by apoptosis and necrosis.
Insights
An enzyme-linked immunosorbent assay (Apoptosis ELISA) effectively quantifies apoptotic cells, distinguishing anticancer drugs from toxic compounds. This assay shows high sensitivity for evaluating drug cytotoxicity in human leukemic cells.
Area of Science:
- Biochemistry
- Cell Biology
- Pharmacology
Background:
- Evaluating the efficacy and toxicity of anticancer drugs is crucial in drug development.
- Distinguishing between apoptosis-inducing anticancer agents and non-apoptotic toxic compounds is essential for therapeutic selection.
Purpose of the Study:
- To evaluate an enzyme-linked immunosorbent assay (Apoptosis ELISA) for its ability to quantify apoptotic cells induced by anticancer drugs and toxic compounds.
- To compare the sensitivity of Apoptosis ELISA with traditional cell survival and MTT assays.
- To determine if Apoptosis ELISA can differentiate between anticancer drugs and toxic chemicals based on their mechanism of cell death.
Main Methods:
- Human leukemic cell cultures were treated with 13 anticancer drugs and 14 toxic chemicals at various concentrations.
- Apoptosis was quantified using an Apoptosis ELISA, which detects single-stranded DNA using a monoclonal antibody.
- Cell viability was assessed using a long-term cell survival assay and a short-term tetrazolium-based microculture tetrazolium (MTT) assay.
Main Results:
- Apoptosis ELISA showed high sensitivity, with absorbance correlating with cytotoxic concentrations for anticancer drugs, similar to the cell survival assay.
- The MTT assay was less sensitive than both Apoptosis ELISA and the cell survival assay for most anticancer drugs.
- Crucially, 14 toxic chemicals did not induce apoptosis at cytotoxic concentrations, unlike the anticancer drugs tested.
Conclusions:
- Apoptosis ELISA is a sensitive and valuable tool for drug development, capable of distinguishing anticancer drugs from toxic compounds.
- The assay provides mechanistic insight into drug cytotoxicity by differentiating apoptosis from necrosis.
- Apoptosis ELISA demonstrates sensitivity comparable to long-term cell survival assays, offering a more rapid assessment of drug effects.
