A new mechanism of methotrexate action revealed by target screening with affinity beads
A new mechanism of methotrexate action revealed by target screening with affinity beads
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DOI：
10.1124/mol.106.025866
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发表时间：
2006-11-01
影响因子：
3.6
通讯作者：
Handa, Hiroshi
中科院分区：
文献类型：
--
作者：
Uga, Hitoshi;Kuramori, Chikanori;Handa, Hiroshi
甲氨蝶呤 (MTX) 是一种抗癌和抗风湿药物，被认为通过抑制二氢叶酸还原酶活性来阻断核苷酸合成和细胞周期。我们开发了新型亲和基质，称为 SG 珠，易于操作且与表面功能化兼容。使用这些矩阵，我们在此证明脱氧胞苷激酶 (dCK)（一种在核苷酸生物合成补救途径中发挥作用的酶）是 MTX 的另一个靶标。 MTX 根据底物浓度不同地调节 dCK 活性。 1-β-D-阿拉伯呋喃糖基胞嘧啶 (ara-C) 是一种化疗药物，通常与 MTX 联合使用，是一种核苷类似物，其掺入染色体需要事先被 dCK 磷酸化。我们发现，值得注意的是，MTX 通过调节 Burkitt 淋巴瘤细胞中的 dCK 活性来增强 ara-C 的掺入和细胞毒性。因此，这项研究提供了对 MTX 作用机制的新见解，并证明了 SG 珠的有用性。
Methotrexate ( MTX) is the anticancer and antirheumatoid drug that is believed to block nucleotide synthesis and cell cycle by inhibiting dihydrofolate reductase activity. We have developed novel affinity matrices, termed SG beads, that are easy to manipulate and are compatible with surface functionalization. Using the matrices, here we present evidence that deoxycytidine kinase ( dCK), an enzyme that acts in the salvage pathway of nucleotide biosynthesis, is another target of MTX. MTX modulates dCK activity differentially depending on substrate concentrations. 1-beta-D-Arabinofuranosylcytosine ( ara-C), a chemotherapy agent often used in combination with MTX, is a nucleoside analog whose incorporation into chromosome requires prior phosphorylation by dCK. We show that, remarkably, MTX enhances incorporation and cytotoxicity of ara-C through regulation of dCK activity in Burkitt's lymphoma cells. Thus, this study provides new insight into the mechanisms underlying MTX actions and demonstrates the usefulness of the SG beads.