Effects of Mitomycin C on Sister Chromatid Exchanges in Cultured Human Lympocytes

항암제 Mitomycin C가 배양임파구의 자매염색분체 교환에 미치는 영향

Sister chromatid exchanges(SCEs) and cell cycle kinetics were proposed as a sensitive and quantitative assay for mutagenicity and cytotoxicity in short-term cultures of phytohema-gglutinin(PHA)-stimu1ated human 1ymphocytes. Therefore, this study was performed to investigate the relation between the cytotoxic effects and sister chromatid exchanges. The resultes are summarized as follows: 1) The frequency of SCEs per cell are $13.1{\pm}2.8$ in the lower concentration of $6.25{\times}10^{-9}M\;and\;75.8{\pm}8.2$ in the highest concentration of $1.00{\pm}10^{-7}M$. Mitotic index is decreased in the higher concentration of mitomycin C. The result indicates that mitomycin C led to a dose dependent increase in SCE frequency, but decease in mitotic index. 2) Chromosomal analysis was performed on metaphase cells that have divided one, two, and three or more times for cell cycle kinetics by fluorescence-plus-Giemsa(FPG) technique. According to the increased concentration of mitomycin C, the proportion of metaphase cells in the first are profoundly increased but the cells of third division are greatly decreased. 3) The frequency of SCEs per chromosome by chromosomal group are decreased gradually from A group to G group. But relationships between specific chromosomal group and SCE frequency are not found.

항암제 mitomycin C가 정상인 배양 임파구의 SCE에 미치는 영향을 알아보기 위해 세포분열지수, 자매염색분체빈도, 세포분열주기 변동 및 염색체군별 SCE 빈도를 조사한 결과는 다음과 같이 요약할 수 있다. 1) 세포당 SCE빈도는 항암제 mitomycin C의 최저농도인 $6.25{\pm}{\times}10^{-9}$ M에서는 $13.1{\pm}2.8$이었고, 최고 농도인 $1.00{\times}10^{-7}$에서는 $75.8{\pm}8.2$로써 농도 증가에 따라 대수증가를 보였다. 그리고 세포분열지수는 완만한 감소경향을 나타냈다. 2) 세포분열주기 변동은 항암제 mitomycin C의 농도 $2.50{\times}10^{-8}M$에서 대조군에 비해 유의한 세포분열지연 현상을 보였으며 (p<0.05), $5{\times}10^{-8}M$ 이상에서는 세포분열지연이 매우 유의하게 나타났다(p<0.01). 3) 염색체군별 단위염색체당 SCE빈도는 항암제의 농도 증가에 따라 절대 빈도는 증가되었다 할지라도 A군에서 G군으로 갈수록 감소되어 특정염색체군과 SCE와의 관계는 보이지 않았다.