著者

吉田 光二 星 昭夫 / 実吉 峯郎 MINEO SANEYOSHI

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.30, no.3, pp.1018-1023, 1982-03-25 (Released:2008-03-31)

参考文献数

23

被引用文献数

4 6

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The mode of antiproliferative action of two 5-fluorocytosine nucleosides, 5-fluoro-cytidine (FCR) and 5-fluoro-2'-deoxycytidine (FCdR), was examined using mouse leukemia L5178Y cells in vitro. FCR and FCdR were markedly active against L5178Y cells, though the cells were deficient in cytidine deaminase activity. Both compounds increased the incorporation of 14C-labeled thymidine into the acid-insoluble fraction of L5178Y cells and decreased labeled deoxycytidine incorporation. In reversal studies, the antiproliferative effects of both compounds were almost abolished by simultaneous addition of thymidine or deoxyuridine. Deoxycytidine completely reversed the growth inhibition caused by FCdR, but not that caused by FCR. These results demonstrate that the cytotoxicity of both compounds is due to inhibition of thymidylate synthetase, presumably through formation of 5-fluoro-2'-deoxyuridine monophosphate (FdUMP) after deamination by deoxycytidylate deaminase in the pyrimidine de novo pathway.