Non-invasive assessment for therapeutic response to gene therapy using redox imaging and MALDI-TOF mass-spectrometry

本研究的目的是建立一种非侵入性的评价基因治疗反应的方法，通过Overhauser MRI（OMRI）评价氧化还原状态和MALDI-TOF质谱分析代谢谱。OMRI分析显示，与对照组相比，TNF-α基因治疗组皮下肿瘤模型的放射性消失曲线比率增加。但在肿瘤与正常组织异质性的腹膜播散方面，两组间无显著差异，提示限制肿瘤面积的氧化还原显像门控技术可能是改善检测的必要手段。在另一项实验中，使用MALDI-TOF质谱法对转染氧化还原相关转录因子：YB-1靶向siRNA后的内皮细胞中的代谢物进行微量分析，结果显示在YB-1-siRNA细胞中NAD减少，组氨酸和天冬氨酸增加。这些结果表明，OMRI对肿瘤区域的可视化（门控）能力的提高可以增强基于氧化还原成像的非侵入性检测来估计对基因治疗的反应。

The purpose of this study is to develop the non-invasive assays to evaluate therapeuticresponse to gene therapy, as the indexes of redox state assessed by Overhauser MRI(OMRI) and metabolic profiling analyzed by MALDI-TOF mass-spectrometry. The ratio of radical disappearance curve analyzed by OMRI was increased for the TNF-αgene therapy compared with the control in subcutaneous tumor model. However, there was no significant difference between two groups in peritoneal dissemination, wherethe heterogeneity of tumor and normal tissues was present, suggesting the gating technology of redox imaging restricting tumor area may be necessary to improve the assay. In a separate experiment, the microanalysis of metabolites in endothelial cells post-transfection of redox-related transcription factor: YB-1-targeting siRNA using MALDI-TOF mass-spectrometry revealed the reduction of NAD and the increase of Histidine and Aspartate in cells with YB-1-siRNA. These results suggest that the improvement of visualizing (gating) ability of OMRI for tumor area could potentiate the redox imaging-based non-invasive assay to estimate the response to gene therapy.