LHRH-PE40融合蛋白锚定的纳米复合体用于成像引导的肿瘤综合治疗研究

In cancer treatment, it is still limited to kill cancer with only one therapeutic agent. Multifunctional nanocomposites integrating a variety of functional molecules can not only inhibit tumor by different mechanisms to improve the efficacy of cancer treatment, with the imaging modality, it's possible to track the process of circulation, biodistribution and target accumulation of nanomedicine, Moreover, it can real-time visualize therapeutic response and provide useful information for dose adjustment, prognosis, and toxicity. By using nanotheranostics, clinical treatment effect and life quality of cancer patients are expected to improve. In this study, we designed a robust theranostic nanomedicine for imaging guided tumor-specific drug delivery and bimodal therapy. The multifunctional nanocomposite was built by bioconjugating a novel tumor target fusion protein of luteinizing hormone-releasing hormone (LHRH) and Pseudomonas aeruginosa exotoxin 40 (PE40) and near-infrared fluorescence (NIRF) molecules of indocyanine green (ICG) onto the polylactic acid - glycolic acid (PLGA) and polyethylene imine (PEI) layer by layer self-assembled nanocarrier loaded with docetaxel (LP-NP-ICG-Dtxl). The imaging moiety of ICG, as the only fluorescent imaging agent approved for clinical application, enables real-time monitoring of circulation, biodistribution and targeted accumulation of the nanocomposites, which can provide important feedback for the treatment of tumors. In LHRH-PE40, which have been approved for clinical trials in China, the LHRH peptide acts as a targeting moiety, whose receptors are specifically overexpressed in several types of cancer cells, such as breast, ovarian, prostate, lung and hepatic cancer cells. PE40 can enter tumor cells by LHRH receptor-mediated endocytosis and causes ribosylation of elongation factor 2 (EF-2), resulting in inhibition of protein synthesis and cell death. In the nanocomposite, two entities, toxin of PE40 and loaded chemotherapeutic drugs of docetaxel (Dtxl) are included to improve the treatment effect by a bimodal therapy with a synergetic effect, which is promising to completely remove the cancer cells. We investigated the targeting non-small cell lung carcinoma A549 cells, which is "LHRH receptor-positive" cancerous cell line, intracellular uptake, tumor specific delivery and tissue distribution of nanocomposites (LP-NP-ICG) by near-infrared fluorescing (NIRF) imaging and evaluated their combined therapy efficacy of toxin treatment and chemotherapy against A549 lung tumor both in vitro and in vivo . Our results will provide new ideas for the comprehensive treatment of lung cancer.

在肿瘤的治疗中，单一的治疗模式很难彻底对肿瘤根治，融合多种功能分子的纳米复合体不仅可以多重作用点上抑制肿瘤，提高肿瘤的治疗疗效，而且合并有成像分子的纳米复合体的体内分布能够被同步监测，为治疗提供反馈，有望提高肿瘤临床治疗效果和患者的生存质量。在这个研究中我们设计和构筑了一种有效的治疗诊断学纳米药物用于成像引导的肿瘤特异性药物输送和双模式治疗。这种多功能纳米复合体通过将肿瘤靶向基因重组融合蛋白LHRH-PE40和近红外荧光分子吲哚菁绿(ICG)偶联于多烯紫杉醇负载的层层自组装纳米载体而构建。我们选择肺癌为肿瘤模型，体外和体内研究该纳米复合体细胞内摄取、肿瘤特异性输送及组织分布，探索纳米复合体介导的肺癌的毒素治疗及化疗的综合治疗模式及同步成像效应的可行性，为肺癌的综合治疗提供新思路。

在肿瘤的治疗中，单一的治疗模式很难彻底对肿瘤根治，融合多种功能分子的纳米复合体不仅可以多重作用点上抑制肿瘤，提高肿瘤的治疗疗效，而且合并有成像分子的纳米复合体的体内分布能够被同步监测，为治疗提供反馈，有望提高肿瘤临床治疗效果和患者的生存质量。在本课题研究中我们设计和构筑了一种有效的治疗诊断学纳米药物用于成像引导的肿瘤特异性药物输送和双模式治疗。这种多功能纳米复合体通过将肿瘤靶向基因重组融合蛋白LHRH-PE40和近红外荧光分子吲哚菁绿(ICG)偶联于多烯紫杉醇负载的纳米载体而构建。ICG作为成像部分，能够实时监测纳米复合体的循环，生物分布和靶向积聚，这可以为肿瘤的治疗提供重要的反馈。纳米复合体利用LHRH的导向功能实现有效的细胞内药物输送和肿瘤靶向输送，更重要的是PE40毒素和负载的化疗药多烯紫杉醇通过不同的作用机制抑制肿瘤，达到双模式联合治疗，提高了治疗效应，有希望彻底杀死肿瘤细胞。我们选择肺癌为肿瘤模型，体外和体内研究该纳米复合体细胞内摄取、肿瘤特异性输送及组织分布，探索纳米复合体介导的肺癌的毒素治疗及化疗的综合治疗模式及同步成像效应的可行性。我们的研究结果表明该纳米复合体能特异靶向输送到肺肿瘤细胞中；该纳米复合体介导的肺癌靶向毒素治疗及化疗的综合治疗模式相比单独的毒素治疗和化疗能显著提高肿瘤的治疗效应；通过近红外成像能监测到纳米复合体的体内肿瘤靶向分布和组织分布。这种纳米复合体能作为成像引导的肿瘤特异性药物输送和双模式治疗的潜在的一种重要的新的工具。我们的研究结果为肺癌的综合治疗提供了新思路。