Synthesis, binding and intracellular retention of methotrexate polyglutamates by cultured human breast cancer cells.
Synthesis, binding and intracellular retention of methotrexate polyglutamates by cultured human breast cancer cells.
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培养的人乳腺癌细胞合成、结合和细胞内保留甲氨蝶呤聚谷氨酸盐。
DOI：
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发表时间：
1983
影响因子：
--
通讯作者：
B. Chabner
中科院分区：
文献类型：
--
作者：
R. Schilsky;J. Jolivet;B. Bailey;B. Chabner
采用凝胶过滤和高压液相色谱分离甲氨蝶呤及其代谢物，研究了培养的人乳腺癌细胞对甲氨蝶呤多谷氨酸的合成、结合和细胞内保留。发现MCF-7、ZR-75-1和MDA-231人乳腺癌细胞在24小时的潜伏期内很容易将甲氨蝶呤转化为更高的多谷氨酸，尽管速率不同。对细胞内与二氢叶酸还原酶特异性结合的那部分甲氨蝶呤的检查显示，随着孵育时间的延长，甲氨蝶呤多谷氨酸成为与酶结合的主要药物形式。同样，甲氨蝶呤多谷氨酸在细胞质中自由积累，当细胞悬浮在无药培养基中时，与二氢叶酸还原酶结合和未结合的部分都保留在细胞内，表明它们通过细胞膜的速度很慢。甲氨蝶呤聚谷氨酸与纯化的细菌二氢叶酸还原酶结合的研究表明，与含有多达6个额外谷氨酰基残基的化合物具有高亲和力结合。这些研究表明，甲氨蝶呤多谷氨酸很容易在人乳腺癌细胞中形成，与细胞内二氢叶酸还原酶结合，并选择性地保留与酶结合和游离在细胞质中。
Synthesis, binding, and intracellular retention of methotrexate polyglutamates by cultured human breast cancer cells were investigated by gel filtration and high-pressure liquid chromatography to separate methotrexate from its metabolites. MCF-7, ZR-75-1, and MDA-231 human breast cancer cells were found to readily convert methotrexate to higher polyglutamates during a 24-hr incubation period, although at differing rates. Examination of that portion of intracellular methotrexate specifically bound to dihydrofolate reductase revealed that, with prolonged incubation, methotrexate polyglutamates become the predominant drug form bound to the enzyme. Similarly, methotrexate polyglutamates accumulated free in the cytosol and when cells were suspended in drug-free medium, were retained intracellularly both bound to dihydrofolate reductase and in the unbound fraction, indicating their slow passage through the cell membrane. Studies of methotrexate polyglutamate binding to purified bacterial dihydrofolate reductase revealed high affinity binding for compounds with up to 6 additional glutamyl residues. These studies demonstrate that methotrexate polyglutamates are readily formed in human breast cancer cells, bind intracellularly to dihydrofolate reductase, and are selectively retained both bound to the enzyme and free in the cell cytosol.
L1210 白血病细胞流出后甲氨蝶呤-聚谷氨酸盐的细胞外回收。
影响因子：
5.8
作者：
Poser,RG;Sirotnak,F;Chello,PL
通讯作者：
Chello,PL