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In vitro germ cell models for the detection of fertility impairment
R Vogel1, A Domke, B Tenschert
1BgVV, Berlin, Germany. r.vogel@bgvv.de
Abstract:
Pluripotent embryonic carcinoma cells and pluripotent embryonic stem cells established from undifferentiated cells of an early mouse embryo were investigated for induction of proliferation inhibition, sister chromatid exchanges (SCE) and single-strand breaks by treatment with various germ cell mutagens. The comparison of malignant cells with nonmalignant cells showed an increased sensitivity of nonmalignant cells independent of their state of differentiation. Mitomycin C (MMC) inhibited the proliferation of nonmalignant cells at a concentration of 10(-6) M but did not affect growth of the teratocarcinoma cell line P19. There were no differences between the investigated cell lines at a lower MMC concentration. At the concentration of 10(-6) M MMC the sister chromatid exchanges of P19 were enhanced up to 41 SCE per metaphase. Testing of another germ cell mutagen, ethylnitrosourea (ENU), gave similar results: a decreasing generation time of nonmalignant cell lines after treatment with 1 mM ENU and no effect on the teratocarcinoma cells. This concentration also induced a high number of SCE. Single-strand breaks could be produced by exposure to methanmethylsulphonate (MMS). 56.3% of embryonic stem cell DNA was passing through the filter after MMS treatment. In contrast to the embryonic stem cells, only 35.6% of teratocarcinoma DNA was affected.
Insights
Malignant teratocarcinoma cells show resistance to DNA damage from germ cell mutagens, unlike sensitive nonmalignant embryonic stem cells. This differential response highlights distinct cellular repair mechanisms in cancer versus normal cells.
Area of Science:
- Cell Biology
- Genetics
- Toxicology
Background:
- Pluripotent embryonic carcinoma cells (teratocarcinoma) and embryonic stem cells (ESCs) are derived from early mouse embryos.
- Investigating their differential responses to mutagens is crucial for understanding cancer biology and DNA repair.
Purpose of the Study:
- To compare the sensitivity of malignant teratocarcinoma cells and nonmalignant ESCs to various germ cell mutagens.
- To assess the induction of proliferation inhibition, sister chromatid exchanges (SCE), and single-strand DNA breaks.
Main Methods:
- Treatment of P19 teratocarcinoma cells and mouse ESCs with Mitomycin C (MMC), ethylnitrosourea (ENU), and methanmethylsulphonate (MMS).
- Monitoring proliferation inhibition, quantifying SCE, and measuring single-strand DNA breaks via filter elution.
Main Results:
- Nonmalignant ESCs exhibited higher sensitivity to MMC and ENU compared to P19 teratocarcinoma cells.
- MMC and ENU induced significant SCE in P19 cells at concentrations that inhibited ESC proliferation.
- MMS treatment caused more single-strand DNA breaks in ESCs (56.3%) than in teratocarcinoma cells (35.6%).
Conclusions:
- Malignant teratocarcinoma cells display resistance to DNA damage induced by specific germ cell mutagens.
- Nonmalignant ESCs are more sensitive to these mutagens, irrespective of their differentiation state.
- Differential sensitivity suggests distinct DNA repair capacities between malignant and nonmalignant pluripotent cells.