Low mutagenic effects of mitomycin C in undifferentiated embryonic P19 cells are correlated with efficient cell cycle control
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- 作者：Sehlmeyer ; Ulrich ; Meister ; Armin ; Beisker ; Wolfgang ; Wobus ; Anna M.
- 关键词：Mitomycin C ; Embryonal carcinoma cell ; Differentiation ; HPRT-mutation ; Micronuclei ; Cell cycle ; Flow cytometry
- 刊名：Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis
- 出版年：1996
- 出版时间：July 5, 1996
- 年：1996
- 卷：354
- 期：1
- 页码：103-112
- 全文大小：697 K
文摘
Pluripotent undifferentiated embryonic carcinoma cells of line P19 and their differentiated progeny, epithelioid ectoderm-like EPI-7 cells, showed different responses to mitomycin C (MMC) with respect to induction of micronuclei, mutations at the HPRT-locus and cell cycle control. Cytotoxic effects of MMC after a 5-h treatment were lower in undifferentiated P19 cells than in differentiated EPI-7 cells with IC50 values of 1.3 and 0.25 μM for P19 and EPI-7 cells, respectively. MMC did not induce 6-thioguanine-resistant mutants in P19 cells but significantly increased the mutation frequency in EPI-7 cells with concentrations of 0.25, 0.5 and 1.0 μM MMC. Micronuclei determined by flow-cytometry were induced by MMC in both cell lines at equitoxic concentrations of 4.5 (P19) and 0.75 (EPI-7) μM, reducing the viability in both cell lines to 10 % . Whereas the induction of micronuclei in P19 cells was maximal 28 h after treatment and declined thereafter, micronucleus induction peaked 48 h post treatment in EPI-7 cells and remained significantly increased even 67 h after the treatment. Flow-cytometric determination of the distribution of MMC-treated P19 and EPI-7 within the cell cycle revealed a distinct G2/M-block in P19 cells, whereas EPI-7 cells showed normal progression through S-phase and a negligible G2/M-block. Therefore, we conclude that the lower effectivity of MMC to induce gene mutations and micronuclei in P19 cells seemed to be correlated with a more efficient cell cycle control in undifferentiated compared to differentiated EPI-7 cells.