Molecular Mechanisms of Patupilone Resistance
Molecular Mechanisms of Patupilone Resistance
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DOI：
10.1158/0008-5472.can-08-2091
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发表时间：
2008-12-15
期刊：
影响因子：
11.2
通讯作者：
Ferlini, Cristiano
中科院分区：
文献类型：
--
作者：
Mozzetti, Simona;Iantomasi, Raffaella;Ferlini, Cristiano
帕土匹隆是一种处于高级临床开发阶段的埃博霉素，在重度预治疗患者中显示出有希望的疗效。本研究的目的是表征耐药患者帕土匹隆活性的机制。为此，我们使用两种细胞模型产生帕土匹隆抗性细胞，第一种以高化学敏感性和低III类β-微管蛋白（TUBB 3）表达（A2780）为特征，第二种以低化学敏感性和高TUBB 3表达（OVCAR-3）为特征。获得的细胞系分别命名为EPO 3和OVCAR-EPO。在A2780细胞中进行相同的选择程序以产生紫杉醇抗性细胞系（TAX 50）。预期耐药细胞系中的耐药因子将增加，而药物敏感性因子将下调。使用这种方法，我们发现TUBB 3在TAX 50细胞中上调，而不是EPO 3细胞，表明TUBB 3介导对紫杉醇的抗性，但不介导对帕土匹隆的抗性。此外，TUBB 3是帕土匹隆敏感性的一个因素，因为OVCAR-EPO细胞表现出TUBB 3的显著减少以及伴随的对缺氧和基于顺铂的化疗的敏感性。为了鉴定帕土匹隆抗性的潜在机制，对微管蛋白基因进行测序，从而揭示了药物抗性的突出机制由I类β-微管蛋白中的点突变代表。总体而言，这些结果表明，紫杉醇和帕土匹隆具有非重叠的耐药机制，因此允许使用帕土匹隆治疗紫杉醇为基础的化疗后复发的患者。此外，帕土匹隆代表了治疗高风险卵巢癌患者的有希望的一线选择，这些患者表现出高TUBB 3水平和对标准紫杉醇-铂化疗的不良反应。[Cancer Res 2008;68（24）：10197-204]
Patupilone is an epothilone in advanced clinical development that has shown promising efficacy in heavily pretreated patients. This study aimed at characterizing the mechanisms of patupilone activity in resistant patients. To this end, we generated patupilone-resistant cells using two cellular models, the first characterized by high chemosensitivity and low class III beta-tubulin (TUBB3) expression (A2780), and the second by low chemosensitivity and high TUBB3 expression (OVCAR-3). The obtained cell lines were named EPO3 and OVCAR-EPO, respectively. The same selection procedure was done in A2780 cells to generate a paclitaxel-resistant cell line (TAX50). Factors of resistance are expected to increase in the drug-resistant cell lines, whereas factors of drug sensitivity will be down-regulated. Using this approach, we found up-regulation of TUBB3 in TAX50, but not EPO3, cells, showing that TUBB3 mediates the resistance to paclitaxel but not to patupilone. Moreover, TUBB3 was a factor of patupilone sensitivity because OVCAR-EPO cells exhibited a dramatic reduction of TUBB3 and a concomitant sensitization to hypoxia and cisplatin-based chemotherapy. To identify the mechanisms underlying patupilone resistance, tubulin genes were sequenced, thereby revealing that a prominent mechanism of drug resistance is represented by point mutations in class I beta-tubulin. Overall, these results suggest that paclitaxel and patupilone have nonoverlapping mechanisms of resistance, thus allowing the use of patupilone for those patients relapsing after paclitaxel-based chemotherapy. Furthermore, patupilone represents a promising first-line option for the treatment of high-risk ovarian cancer patients, who exhibit high TUBB3 levels and poor response to standard paclitaxel-platin chemotherapy. [Cancer Res 2008;68(24):10197-204]