Hyperthermia adds to trabectedin effectiveness and thermal enhancement is associated with BRCA2 degradation and impairment of DNA homologous recombination repair
Hyperthermia adds to trabectedin effectiveness and thermal enhancement is associated with BRCA2 degradation and impairment of DNA homologous recombination repair
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DOI：
10.1002/ijc.30070
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发表时间：
2016-07-15
影响因子：
6.4
通讯作者：
Issels, Rolf D.
中科院分区：
文献类型：
--
作者：
Harnicek, Dominique;Kampmann, Eric;Issels, Rolf D.
四氢异喹啉trabetedin是一种海洋化合物，具有抗人类软组织肉瘤的活性。它主要通过特异性结合DNA和诱导DNA双链断裂（DSB）发挥抗增殖活性。由于同源重组修复（HRR）缺陷型肿瘤对曲贝替丁更敏感，因此高血压介导的HRR缺陷按需诱导代表了一种新的有前景的策略，以促进曲贝替丁治疗。这是第一次，我们证明了热增强人肉瘤细胞系中trabectedin的有效性，并表征了与热诱导效应相关的细胞事件和分子机制。高温（41.8或43摄氏度）显着增强了trabetedin相关的克隆性细胞死亡和G2/M细胞周期停滞，随后是细胞类型依赖性的细胞凋亡或衰老诱导。热组合增加了作为DSB的关键标志物的γ H2 AX灶的积累。BRCA 2蛋白的表达，一个完整的蛋白质的HRR机器，显着降低热。因此，招募下游RAD 51 γ H2 AX阳性修复灶几乎被废除，表明热HRR的相关损害。因此，在BRCA 2-proficient细胞中通过高温显著增强了trabectedin有效性的增强，并且在BRCA 2敲除或siRNA转染的BRCA 2敲除细胞中减轻了。在从肉瘤患者分离的外周血单核细胞中，在用曲贝替定和肿瘤区域的高温全身治疗后检测到核γ H2 AX灶的数量增加。这些发现确立了BRCA 2热降解是一种新型治疗策略的关键因素，该策略通过按需诱导HRR缺陷，允许对trabectedin和其他DNA损伤抗肿瘤药物进行靶向化疗增敏。
The tetrahydroisoquinoline trabectedin is a marine compound with approved activity against human soft-tissue sarcoma. It exerts antiproliferative activity mainly by specific binding to the DNA and inducing DNA double-strand breaks (DSB). As homologous recombination repair (HRR)-deficient tumors are more susceptible to trabectedin, hyperthermia-mediated on-demand induction of HRR deficiency represents a novel and promising strategy to boost trabectedin treatment. For the first time, we demonstrate enhancement of trabectedin effectiveness in human sarcoma cell lines by heat and characterize cellular events and molecular mechanisms related to heat-induced effects. Hyperthermic temperatures (41.8 or 43 degrees C) enhanced significantly trabectedin-related clonogenic cell death and G2/M cell cycle arrest followed by cell type-dependent induction of apoptosis or senescence. Heat combination increased accumulation of gamma H2AX foci as key marker of DSBs. Expression of BRCA2 protein, an integral protein of the HRR machinery, was significantly decreased by heat. Consequently, recruitment of downstream RAD51 to gamma H2AX-positive repair foci was almost abolished indicating relevant impairment of HRR by heat. Accordingly, enhancement of trabectedin effectiveness was significantly augmented in BRCA2-proficient cells by hyperthermia and alleviated in BRCA2 knockout or siRNA-transfected BRCA2 knockdown cells. In peripheral blood mononuclear cells isolated from sarcoma patients, increased numbers of nuclear gamma H2AX foci were detected after systemic treatment with trabectedin and hyperthermia of the tumor region. The findings establish BRCA2 degradation by heat as a key factor for a novel treatment strategy that allows targeted chemosensitization to trabectedin and other DNA damaging antitumor drugs by on-demand induction of HRR deficiency.