Mutants of human colon adenocarcinoma, selected for thymidylate synthase deficiency.
Mutants of human colon adenocarcinoma, selected for thymidylate synthase deficiency.
复制标题
人类结肠腺癌突变体，因胸苷酸合酶缺乏而被选择。
DOI：
10.1073/pnas.86.4.1377
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发表时间：
1989
影响因子：
11.1
通讯作者：
Houghton,JA
中科院分区：
文献类型：
--
作者：
Houghton,PJ;Germain,GS;Hazelton,BJ;Pennington,JW;Houghton,JA
GC3/c1 human colon adenocarcinoma cells were treated with the mutagen ethyl methanesulfonate, and three clones deficient in thymidylate synthase (5,10-methylenetetrahydrofolate:dUMP C-methyltransferase, EC 2.1.1. 45) activity were selected and characterized. Growth in medium deficient in thymidine caused cell death in two clones (TS- c1 and TS- c3), whereas one clone (TS- c2) showed limited growth. Growth correlated with thymidine synthase activity and 5-fluoro-2'-deoxyuridine 5'-monophosphate-binding capacity and with incorporation of 2'-deoxy[6-3H]uridine into DNA. In the presence of optimal thymidine, growth rates were only 5-18% that of the parental clone (GC3/c1), which grew equally well in thymidine-deficient or -replete medium. Analysis of poly(A)+ RNA showed normal levels of a 1.6-kilobase transcript in TS- c1 and TS- c2 but decreased levels (approximately 6% control) in TS- c3. Clone TS- c3 was 32-, 750-, and greater than 100,000-fold more resistant than the parental clone to 5-fluorouracil, 5-fluoro-2'-deoxyuridine, and methotrexate, respectively. When inoculated into athymic nude mice, each TS- clone produced tumors, demonstrating continued ability to proliferate in vivo.
