GS-164, a small synthetic compound, stimulates tubulin polymerization by a similar mechanism to that of Taxol
GS-164, a small synthetic compound, stimulates tubulin polymerization by a similar mechanism to that of Taxol
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DOI：
10.1007/s002800050695
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发表时间：
1997-10-01
影响因子：
3
通讯作者：
Nozaki, Y
中科院分区：
文献类型：
--
作者：
Shintani, Y;Tanaka, T;Nozaki, Y
目的：在我们寻找新的微管效应物作为抗癌剂的过程中，我们发现一种名为GS-164的小合成分子干扰猪微管蛋白的组装，并对广泛的人类肿瘤细胞系具有细胞毒性活性。在这项研究中，我们调查了该化合物的作用模式，与紫杉醇和秋水仙胺比较。研究方法：为了深入了解GS-164的作用模式，我们使用了体外微管聚合试验和流式细胞术测量技术。微管组织和微管蛋白聚合的HeLa细胞的水平也分别通过免疫荧光显微镜和细胞骨架蛋白分析。结果：GS-164在体外以浓度依赖性和GTP非依赖性的方式刺激微管蛋白的组装。此外，与紫杉醇一样，GS-164诱导的微管聚合可被微管蛋白聚合抑制剂鬼臼毒素拮抗，GS-164形成的微管可抵抗钙或低温的分解。微摩尔浓度范围内的GS-164使HeLa细胞的细胞周期停滞在有丝分裂期，导致细胞死亡。GS-164还增加了HeLa细胞中细胞微管的数量，导致微管束的形成。结论：GS-164刺激微管组装的机制与紫杉醇相似。GS-164和紫杉醇的比较构象分析表明，前者的结构模拟了发挥上述紫杉醇样活性所需的紫杉醇的最小必需位点。虽然GS-164对人肿瘤细胞的细胞毒性比紫杉醇低1000倍，并且GS-164在体外的活性是紫杉醇的十分之一，但这些发现为使用GS-164作为先导化合物合成临床有用的抗癌剂铺平了道路。
Purpose: During our search for new microtubule effecters as anticancer agents, we have found that a small synthetic molecule designated GS-164 interferes with the assembly of porcine microtubule proteins and has cytotoxic activity against a wide range of human tumor cell lines. In this study, we investigated mode of action of the compound in comparison with Taxol and colcemid. Methods: To gain an insight into the mode of action of GS-164, we used an in vitro microtubule polymerization assay and a flow-cytometric measurement technique. Microtubule organization and the level of tubulin polymerization in HeLa cells were also examined by immunofluorescence microscopy and cytoskeletal protein analyses, respectively. Results: GS-164 stimulated assembly of microtubule proteins in vitro in a concentration-dependent and a GTP-independent manner. Furthermore, as with Taxol, the microtubule polymerization induced by GS-164 was antagonized by podophyllotoxin, a tubulin polymerization inhibitor, and microtubules formed by GS-164 were resistant to disassembly by calcium or low temperatures. GS-164 in the micromolar range arrested the cell cycle of HeLa cells in the mitotic phase leading to cell death. GS-164 also increased the amounts of cellular microtubules in HeLa cells, resulting in the formation of microtubule bundles. Conclusion: These results indicate that GS-164 stimulates microtubule assembly by a similar mechanism to that of Taxol. A comparative conformational analysis of GS-164 and Taxol suggested that the structure of the former mimics the minimum essential sites of Taxol required to exert the Taxol-like activities described above. Although the cytotoxicity of GS-164 against human tumor cells was 1000-fold lower than that of Taxol and GS-164 was one-tenth as active as Taxol in vitro, these findings pave the way for synthesizing clinically useful anticancer agents using GS-164 as a lead compound.