Dual targeting of EWS-FLI1 activity and the associated DNA damage response with trabectedin and SN38 synergistically inhibits Ewing sarcoma cell growth.
Dual targeting of EWS-FLI1 activity and the associated DNA damage response with trabectedin and SN38 synergistically inhibits Ewing sarcoma cell growth.
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DOI：
10.1158/1078-0432.ccr-13-0901
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发表时间：
2014-03-01
期刊：
影响因子：
--
通讯作者：
Helman LJ
中科院分区：
文献类型：
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作者：
Grohar PJ;Segars LE;Yeung C;Pommier Y;D'Incalci M;Mendoza A;Helman LJ
本研究的目的是通过开发一种分子靶向联合治疗来优化Trabectedin对尤文肉瘤的活性。我们最近发现，trabectedin干扰尤文肉瘤细胞中EWS-FLI 1的活性。在这份报告中，我们建立在这项工作的基础上，开发了一种基于trabectedin的联合治疗，改善了EWS-FLI 1抑制，也靶向了药物相关的ES细胞DNA损伤。我们通过siRNA实验证明EWS-FLI 1驱动ES细胞中Werner综合征蛋白（WRN）的表达。由于已知WRN缺陷细胞对喜树碱超敏，我们利用trabectedin阻断EWS-FLI 1活性，抑制WRN表达，并选择性地使ES细胞对SN 38的DNA损伤作用敏感。我们发现trabectedin和SN 38是协同的，证明了DNA双链断裂的增加，S期细胞的积累和低皮摩尔IC 50。此外，SN 38与trabectedin协同作用，增强了对EWS-FLI 1下游靶点的抑制，从而提高了体内治疗指数。这些作用转化为两种尤文肉瘤异种移植物在其他异种移植物研究中使用的喜树碱剂量的一部分下的显著消退。这些结果为将这种药物组合转化为临床提供了基础和理论依据。此外，该研究强调了一种利用靶向药物干扰致癌转录因子，然后利用基因表达的变化来开发分子靶向联合治疗的方法。
The goal of this study is to optimize the activity of trabectedin for Ewing sarcoma by developing a molecularly targeted combination therapy. We have recently shown that trabectedin interferes with the activity of EWS-FLI1 in Ewing sarcoma cells. In this report, we build on this work to develop a trabectedin based combination therapy with improved EWS-FLI1 suppression that also targets the drug associated DNA damage to ES cells. We demonstrate by siRNA experiments that EWS-FLI1 drives the expression of the Werner Syndrome protein (WRN) in ES cells. Since WRN deficient cells are known to be hypersensitive to camptothecins, we utilize trabectedin to block EWS-FLI1 activity, suppress WRN expression and selectively sensitize ES cells to the DNA damaging effects of SN38. We show that trabectedin and SN38 are synergistic, demonstrate an increase in DNA double strand breaks, an accumulation of cells in S-phase and a low picomolar IC50. In addition, SN38cooperates with trabectedin to augment the suppression of EWS-FLI1 downstream targets, leading to an improved therapeutic index in vivo. These effects translate into the marked regression of two Ewing sarcoma xenografts at a fraction of the dose of camptothecin used in other xenograft studies. These results provide the basis and rationale for translating this drug combination to the clinic. In addition, the study highlights an approach that utilizes a targeted agent to interfere with an oncogenic transcription factor and then exploits the resulting changes in gene expression to develop a molecularly targeted combination therapy.