Sensitization by Radio-Chemotherapy in Targeting Therapy for Survival Signal Transduction Pathways against Head and Neck Cancers

头颈癌生存信号转导通路靶向治疗中放化疗增敏

基本信息

批准号：
18591880
负责人：
YANE Katsunari
金额：
$ 2.36万
依托单位：
Nara Medical University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18591880/
关键词：
head and neck cancer molecular target siRNA radiotherapy chemotherapy p53 gene DNA repair apoptosis

项目摘要

NBS1 is essential for the repair of DNA double-strand breaks (DSBs) and may play a important role in the homologous recombination repair and nonhomologous end joining repair. In this study, we examined whether suppressed NBS1 expression by small interference RNA (siRNA) could enhance radiation sensitivity in cancer cells with different TP53 status. We used human tongue cancer cells differing in TP53 gene status (SAS/neo bearing wild-type TP53 or SAS/mp53 bearing mutant TP53). A DNA cassette expressing siRNA targeted for the NBS1 gene was transfected into those cell lines. Cellular levels of NBS1 and other proteins were analyzed using Western blotting. We found that the radiation sensitivity of SAS/neo and SAS/mp53 was enhanced by transfection of the DNA cassette. In the NBS1-siRNA-transfected cells, we observed decreased constitutive expression of NBS1 protein and decreased radiation-induced accumulation of phosphorylated NBS1 protein. In addition, radiation-induced expression of the transcription factor NF-kB was suppressed by NBS1-siRNA. Enhanced X-ray sensitivity after NBS1-siRNA transfection was achieved in TP53 wild-type cells and sensitivity was even more pronounced in TP53 mutant cells. Our data suggest that the sensitization to radiation results from NBS1-siRNA-mediated suppression of DNA repair and/ or X-ray-induced cell survival signaling pathways through NF-kB. siRNA targeting appears to be a novel radiation-sensitizing agent, particularly in human TP53 mutant cancer cells.

NBS1对于修复DNA双链断裂（DSB）至关重要，并且可能在同源重组修复和非同源末端连接修复中起重要作用。在这项研究中，我们检查了小干扰RNA（siRNA）抑制NBS1表达是否可以增强TP53状态不同的癌细胞的辐射敏感性。我们使用了TP53基因状态不同的人舌癌细胞（SAS/NEO轴承TP53或SAS/MP53轴承突变体TP53）。将靶向NBS1基因的siRNA的DNA盒转染到这些细胞系中。使用蛋白质印迹分析了NBS1和其他蛋白质的细胞水平。我们发现，通过转染DNA盒，SAS/NEO和SAS/MP53的辐射灵敏度得到了增强。在NBS1-SIRNA转染的细胞中，我们观察到NBS1蛋白的组成型表达降低，并降低了磷酸化NBS1蛋白的辐射诱导的积累。另外，NBS1-SIRNA抑制了辐射诱导的转录因子NF-KB的表达。在TP53野生型细胞中实现了NBS1-SIRNA转染后增强的X射线灵敏度，在TP53突变细胞中，灵敏度更为明显。我们的数据表明，通过NBS1-SIRNA介导的DNA修复和/或X射线诱导的细胞存活信号通路通过NF-KB抑制了辐射的敏化。 siRNA靶向似乎是一种新型的辐射敏化剂，特别是在人TP53突变癌细胞中。