靶向肝癌EpCAM+肿瘤干细胞双模分子影像探针构建及其在肝癌早期诊断中的实验研究

The diagnosis of early stage hepatocarcinoma is difficult, and its prognosis is poor. Seeking the early diagnostic method of hepatocarcinoma may be the key approach to improve the prognosis, and the theory of the cancer stem cell put forward to bring new direction to the tumor diagnosis and treatment. Our subject focus on the liver cancer stem cells, we prepared dual-modal molecular imaging probe which by means of cancer stem cell surface specific marker as a target; rare earth upconversion luminescent materials, gadolinium doped as imaging agent cover the two imaging of MRI and optical signal, and by using pH sensitive hydrazone bond, we connect the surface of probe with quench factor, imply the pH responsivity of probe. We use orthotropic tumor model to evaluate whether it can successfully targeting the EpCAM+ cancer stem cells; furthermore, we systematic review its value in hepatocarcinoma early diagnosis and neoplasm metastasis by the living, continuous, real time observation.The results of our project provide an important experimental base expected to clinical application, and also play a role in promoting the establishment of the tumor early diagnosis and non-invasive real-time evaluation of tumor treatment.

肝癌早期诊断困难、预后极差，寻求肝癌早期诊断方法是目前改善预后的关键之一，而肿瘤干细胞理论的提出给肿瘤诊断带来新的方向。本课题以肝癌干细胞为着眼点，以肝癌干细胞表面特异性标志物EpCAM为靶点，钆掺杂NaYF4:Yb/Er稀土上转换发光纳米材料为显像剂，制备MRI和光学双模态分子影像探针来主动靶向肝癌干细胞，并且，通过利用pH敏感腙键向探针分子表面连接淬灭因子，实现探针的pH响应性。以种植EpCAM+癌干细胞肝癌裸鼠原位移植瘤为模型，对探针靶向性进行评价。并通过活体、连续、实时观察，系统研究其在肝癌早期诊断、转移监测中的应用价值，本项目的研究结果有望为相关的临床应用提供重要的实验性研究基础，对于肝癌早期诊断方法的建立也可能起到一定的推动作用。

本课题首先进行了CD90+肝癌干细胞的分离、培养、纯化、鉴定；接着成功制备表面耦连抗CD90单克隆抗体、钆掺杂的NaYF4:Yb/Er稀土上转换发光纳米材料；最后，从体内外成像实验两个水平，验证了这种复合稀土上转换发光纳米材料对CD90+肝癌干细胞的靶向作用。与国内外相关研究比较，本研究课题的特色是：提出并验证了一种全新的靶向肿瘤干细胞的复合稀土上转换发光纳米材料，系统研究其在成像诊断、疗效评估、转移监测等方面的价值，具有一定的临床应用潜力。