Cancer Chemotherapy and Pharmacology, 2011, 68(4):1033-44.

A genistein derivative, ITB-301, induces microtubule depolymerization and mitotic arrest in multidrug-resistant ovarian cancer

Ahmed Ashour Ahmed, et al

Department of Experimental Therapeutics, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd, Unit 422, Houston, TX 77030, USA; et al

PURPOSE:To investigate the mechanistic basis of the anti-tumor effect of the compound ITB-301.

METHODS: Chemical modifications of genistein have been introduced to improve its solubility and efficacy. The anti-tumor effects were tested in ovarian cancer cells using proliferation assays, cell cycle analysis, immunofluorescence, and microscopy.

RESULTS: In this work, we show that a unique glycoside of genistein, ITB-301, inhibits the proliferation of SKOv3 ovarian cancer cells. We found that the 50% growth inhibitory concentration of ITB-301 in SKOv3 cells was 0.5 μM. Similar results were obtained in breast cancer, ovarian cancer, and acute myelogenous leukemia cell lines. ITB-301 induced significant time- and dose-dependent microtubule depolymerization. This depolymerization resulted in mitotic arrest and inhibited proliferation in all ovarian cancer cell lines examined including SKOv3, ES2, HeyA8, and HeyA8-MDR cells. The cytotoxic effect of ITB-301 was dependent on its induction of mitotic arrest as siRNA-mediated depletion of BUBR1 significantly reduced the cytotoxic effects of ITB-301, even at a concentration of 10 μM. Importantly, efflux-mediated drug resistance did not alter the cytotoxic effect of ITB-301 in two independent cancer cell models of drug resistance.

CONCLUSION: These results identify ITB-301 as a novel anti-tubulin agent that could be used in cancers that are multidrug resistant. We propose a structural model for the binding of ITB-301 to α- and β-tubulin dimers on the basis of molecular docking simulations. This model provides a rationale for future work aimed at designing of more potent analogs.

德国《癌症化疗和药理学》，2011年10月

染料木黄酮衍生物，ITB-301，在抗药性卵巢癌中诱导微管解聚和有丝分裂中止

艾哈迈德 阿索尔 艾哈迈德等

美国德克萨斯州大学安德森癌症中心实验治疗部

目的︰ 探讨化合物ITB-301抗肿瘤作用的理论基础。

方法︰引入化学修饰的金雀异黄素，以提高其溶解性和有效性。在卵巢癌细胞中使用增生试验、 细胞周期分析、 免疫荧光法和显微镜来测试其抗肿瘤作用。

结果︰ 在这项工作中，我们发现一种独特的染料木黄酮糖苷，ITB-301，抑制了卵巢癌细胞SKOv3的增殖。我们发现在SKOv3 细胞中ITB30150%生长抑制浓度为 0.5 μ M。在乳腺癌、 卵巢癌和急性髓系白血病细胞中得到类似的结果。ITB-301 引起明显的时间和剂量依赖性微管解聚。这种解聚导致了有丝分裂的中止和抑制所有卵巢癌细胞包括 SKOv3、 ES2，HeyA8 和 HeyA8-MDR细胞的增殖。ITB-301 的细胞毒性效应取决于其对有丝分裂中止的感应 ，当即使在 10 μ M 浓度BUBR1的 siRNA-介导损耗显著降低 ITB-301的细胞毒性作用。重要的是，在两个独立的耐药癌症细胞模型中，射流介导的耐药性并没有改变 ITB-301 的细胞毒性效应。

结论︰ 这些结果证明ITB-301新型反微管蛋白试剂，可用于耐多种药物的肿瘤。我们提出了一个基于分子对接原理将ITB-301 绑定到 α-和 β-微管蛋白二聚体的结构模型。此模型提供了一个用于未来设计更强效核苷类药物的基本理论。