CT／光学成像活体监测ErbB2/HER2和SLUG双靶点介导的非小细胞肺癌光热消融与基因治疗

The intracellular thermal ablation, which is mediated by nanoparticles, is a prospective method for cancer treatment. But residual cancer cells, those were not ablated completely, usually stimulate to start the pathway of angiogenesis and endothelial-mesenchymal transition (EMT), resulting in tumor recurrence. SLUG is known as an important regulating molecule for angiogenesis and EMT. We suppose that down-regulating the SLUG expression will inhibit angiogenesis and EMT, to prevent the tumor recurrence after thermal ablation. In this study, based on the results of our previous works, we will design and synthesize the Herceptin- (NH4) xWO3-SLUGsiRNA as the the multifunctional nanoprobes for the targeted CT / optical imaging and photothermal / gene therapy of non-small cell lung cancer (NSCLC) cells. Herceptin will help the nanoprobes to specifically bind with the HER2, which overexpressed on the surface of NSCLC cells, and will block the HER2 signaling pathway of NSCLC cells. SLUGsiRNA will knock down the expression of SLUG to inhibiting angiogenesis and EMT of NSCLC cells. The (NH4) xWO3 nanorods, which uptaken by cancer cells, will trigger by the near-infrared laser to achieve the intracellular photothermal therapy. The efficacy of this photothermal ablation and gene therapy will be monitored and evaluated by targeted CT / optical imaging of NSCLC. The results from this study will clarify the synergistic enhancement effect of the photothermal ablation and gene therapy on NSCLC cells, and explore a new method of theranostics for NSCLC.

纳米材料介导细胞内热消融有望成为肿瘤治疗的新方法，但消融不彻底会刺激残存的癌细胞启动血管生成和内皮-间质转化(EMT)，导致残瘤复发。已知SLUG是血管生成和EMT的重要调节靶点。我们据此推测：下调癌细胞SLUG基因表达，可抑制血管生成和EMT，阻止热消融后的残瘤复发。本项目在前期工作基础上，构建非小细胞肺癌（NSCLC）的靶向性CT／光学成像与光热／基因治疗的一体化纳米探针——Herceptin- (NH4)xWO3-SLUGsiRNA。以Herceptin靶向结合NSCLC细胞表面的HER2靶点，并阻断癌细胞HER2信号通路；以SLUGsiRNA下调癌细胞SLUG表达，抑制血管生成和EMT；并通过近红外光激发进入细胞的(NH4)xWO3实现细胞内光热治疗；同时活体监测此光热消融与基因治疗的疗效。阐明NSCLC细胞内光热消融与双靶点基因治疗之间的协同增强效应，为NSCLC诊治探索新方法。

本项目成功构建CT/光学双模态成像和细胞内光热治疗一体化纳米探针PEGylated (NH4)xWO3，实现纳米探针的诊疗一体化；构建多种靶向性多功能诊治一体化纳米探针，证实纳米探针可靶向肿瘤细胞，并实现光热消融、聚焦超声消融、靶向化疗、声动力治疗等多种治疗方式的联合治疗，采用光学/CT／MR多模态成像方式实时监测治疗效果、按需释放药物，并对其治疗效果进行综合评价评价，实现肿瘤的分子成像、细胞示踪与诊疗一体化。本项目研究成果包括：1）构建诊疗一体化纳米探针PEGylated (NH4)xWO3，实现CT/光学成像的同时，对肿瘤细胞进行光热消融治疗，证实该探针具有稳定且高效的光热治疗效果。2）制备基于Fe3O4的超微结构的纳米探针Fe3O4–PEG–CysNPs，平均粒径约3.2nm，成功实现血池及肿瘤的MR成像。3）构建基于肿瘤微环境中PH响应的纳米探针--- BSNSs-CAT，使其在肿瘤细胞周围的酸性环境中完全解体，释放出铋元素，同时联合放疗，达到放疗增敏的效果，加强肿瘤细胞的凋亡。4）构建诊疗一体化纳米探针系统--聚乙二醇化过氧化氢酶(PEGylated CAT, nCAT)，采用聚焦超声消融及化疗的联合治疗方案，杀死靶区肿瘤细胞，证实联合治疗FUS +DOX组肿瘤细胞的凋亡水平最高。5）为实时监测肿瘤组织的治疗效果，按需调节药物释放浓度，成功构建一个基于转铁蛋白(holo -transferrin, holo - Tf)，原位生长MnO2纳米晶体的智能纳米平台，并将原卟啉(ppIX)作为声敏剂偶联到纳米颗粒中，在成功实现高特异性的原位胶质母细胞瘤MR成像的同时，通过声动力疗法抑制了肿瘤生长，结果显示TMP+声动力治疗实验组具有明显的细胞凋亡。