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Sister chromatid exchange frequency, cellular replication and relative cloning efficiency in human
S M Morris1, O E Domon, R L Kodell
1Department of Health and Human Services, Food and Drug Administration, National Center for Toxicological Research, Jefferson, Arkansas 72079.
Abstract:
To determine the relationships between the induction of specific biological responses and exposure to DNA-damaging agents, human teratocarcinoma-derived cells were exposed to either ethyl methanesulfonate or to methyl methanesulfonate, and sister chromatid exchange, cellular proliferation and relative cloning ability measured. SCE increased while cellular proliferation and relative cloning ability each decreased in a concentration-dependent manner. Methyl methanesulfonate was consistently more efficient in inducing biological responses than was ethyl methanesulfonate. When the individual responses were compared, the decrease in cellular proliferation paralleled the reduction in cloning efficiency. A strong correlation was also observed between the reduction in relative cloning ability and sister chromatid exchange frequency. Because these relationships are similar to those previously described in other mammalian cell lines, the observations in our study suggest that the P3 cell line is an appropriate choice for modeling effects of toxicant exposure in human cells.
Insights
This study shows that exposure to DNA-damaging agents like methyl methanesulfonate increases sister chromatid exchange while decreasing cellular proliferation and cloning ability in human cells. The P3 cell line is suitable for toxicant exposure modeling.
Area of Science:
- Toxicology
- Cell Biology
- Genetics
Background:
- DNA-damaging agents can induce various biological responses in cells.
- Understanding these responses is crucial for assessing toxicant effects.
- Human teratocarcinoma-derived cells offer a model for studying cellular responses to genotoxicity.
Purpose of the Study:
- To investigate the relationship between exposure to DNA-damaging agents and specific biological responses.
- To evaluate the dose-dependent effects of ethyl methanesulfonate and methyl methanesulfonate on human cells.
- To determine the suitability of the P3 cell line for toxicological studies.
Main Methods:
- Human teratocarcinoma-derived P3 cells were exposed to varying concentrations of ethyl methanesulfonate and methyl methanesulfonate.
- Sister chromatid exchange (SCE) frequency was measured.
- Cellular proliferation and relative cloning ability were assessed.
Main Results:
- Sister chromatid exchange (SCE) frequency increased in a concentration-dependent manner.
- Cellular proliferation and relative cloning ability decreased with increasing concentrations of DNA-damaging agents.
- Methyl methanesulfonate was more potent than ethyl methanesulfonate in inducing biological responses.
- A strong correlation was found between reduced cloning efficiency and increased SCE frequency.
Conclusions:
- The P3 cell line exhibits predictable biological responses to DNA-damaging agents.
- Cellular proliferation and cloning ability are sensitive indicators of genotoxicity.
- The observed relationships suggest the P3 cell line is a relevant model for human toxicant exposure studies.