Torc1/Torc2 inhibitor, Palomid 529, enhances radiation response modulating CRM1-mediated survivin function and delaying DNA repair in prostate cancer models
Torc1/Torc2 inhibitor, Palomid 529, enhances radiation response modulating CRM1-mediated survivin function and delaying DNA repair in prostate cancer models
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DOI：
10.1002/pros.22804
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发表时间：
2014-06-01
期刊：
影响因子：
2.8
通讯作者：
Festuccia, Claudio
中科院分区：
文献类型：
--
作者：
Gravina, Giovanni Luca;Marampon, Francesco;Festuccia, Claudio
Torc 1/Torc 2抑制剂PGROUNDP 529已被证明具有放射增敏作用。然而，这一现象背后的分子机制仍然需要阐明。本研究的目的是剖析分子机制调节P529的放射增敏性能在一个广泛的面板前列腺癌models.METHODSSix肿瘤细胞系和异种移植模型被用于在体外和体内研究。克隆形成存活、凋亡、自噬和衰老测定用于检查单独的电离辐射（IR）和与P529组合的影响。通过蛋白质印迹法监测P529和RT后CRM 1、生存素、GSK-3 β和DNA-DSB的表达和调节。通过肿瘤体积、肿瘤进展时间（TTP）和免疫组化分析监测P529、放疗或P529与IR联合治疗后的体内治疗反应。TSP 529治疗与放疗联合治疗时，可显著诱导更多的细胞凋亡和DNA双链断裂（DSB），从而导致细胞放射增敏和照射肿瘤异种移植物的生长延迟。P529处理后，Rad 51、DNA-PKcs和Ku 70蛋白表达下调，表明DNA双链损伤修复延迟。P529的放射增敏特性部分与GSK-3 β、细胞周期蛋白-D1和c-myc调节相关，并与CRM 1介导的生存素核输出抑制相关。重要的是，自噬和肿瘤衰老参与增强P529 radioresponsibility. CONCLUSION受损的DNA双链损伤修复，抑制CRM 1介导的生存素的核出口，调制细胞周期蛋白-D1和c-myc与相关的促凋亡和自噬和衰老事件解释了P529在前列腺癌的临床前模型的放射增敏特性。前列腺74：852-868，2014年。(c)2014 Wiley Periodicals，Inc.
BACKGROUNDP529, a Torc1/Torc2 inhibitor, has demonstrated its potential as a radiosensitizer. However the molecular mechanisms underlying this phenomenon still need to be elucidated. Aim of this study is to dissect molecular mechanisms regulating the radiosensitizing properties of P529 in a wide panel of prostate cancer models.METHODSSix tumor cell lines and xenograft models were used for in vitro and in vivo studies. Clonogenic survival, apoptotic, autophagic, and senescence assays were used to examine the effects of ionizing radiation (IR) alone and in combination with P529. CRM1, survivin, GSK-3 beta, and DNA-DSBs expression and modulation, upon P529 and RT, were monitored by western blot. In vivo treatment response upon P529, irradiation or combination of P529 with IR was monitored by tumor volume, time to progression (TTP), and immunohistochemical analysis.RESULTSP529 treatment induced significantly more apoptosis and DNA double-strand break (DSB) when combined with radiotherapy resulting in cellular radiosensitization and growth delay of irradiated tumor xenografts. Upon P529 treatment Rad51, DNA-PKcs, and Ku70 protein expression was downregulated, indicating delayed DNA double-strand damage repair. The radiosensitizing properties of P529 were partially linked to GSK-3 beta, cyclin-D1, and c-myc modulation with associated inhibition of CRM1-mediated nuclear export of survivin. Importantly, autophagy and tumor senescence were involved in the enhanced P529 radioresponse.CONCLUSIONSImpaired DNA double-strand damage repair, inhibition of CRM1-mediated nuclear export of survivin, modulation of cyclin-D1 and c-myc with associated pro-apoptotic and autophagic and senescent events explain the radiosensitizing properties of P529 in preclinical models of prostate cancer. Prostate 74:852-868, 2014. (c) 2014 Wiley Periodicals, Inc.