载药纳米超声微泡多维抑制肿瘤相关性巨噬细胞对肝癌的辅助治疗作用

Cancer-related inflammation is considered the seventh hallmark of tumor, and the turmor-associated macrophages（TAM）play the core role in the Inflammatory process and promote the malignant behavior of tumor. In response to microenvironmental signals, TAM can exert dual influence on tumor growth and progression. Classically activated macrophages (M1), take a part in the Th1 type of immune response, and have anti-infection and anti-tumor activity. But reactions alternatively activated, 'M2', phenotype, associated with immunosuppression of Th1, promotion of tumor angiogenesis and metastasis.Our previous studies have found that Kupffer cells plays an importatant role in the Occurrence, development and invasion of hepatocellular carcinoma. M2-type macrophages accounts for the majority of Kupffer cells in the advanced hepatocellular carcinoma, the less Kupffer cells a smaller likelihood of malignant behavior. On the contrary, Local abscess, accelerated tumor growth and Increased mortality was found in the tumor bearing mice because the clearance of Kupffer cells weakened anti-infection and anti-tumor activity of M1-type macrophages in early hepatocellular carcinoma. In the project,from the perspective of signal transcription and gene regulation,the Kupffer cells are chosen as the target cell and Ultrasound-targeted microbubble destruction technique are used to elucidate the effective inhibition of M2-type macrophages, to explore its effect on prognosis of the tumor bearing mice and do some exporatory work for using it for the treatment of hepatocellular carcinoma.

肿瘤相关性巨噬细胞（TAM）作为肿瘤相关性炎症的核心，通过多途径促进了肿瘤的恶性行为。TAM分化的不同亚型在肿瘤的形成过程中的作用并不相同，其中经典活化型（M1型）参与Th1型免疫应答，发挥抗感染、抗肿瘤的效应;替代活化型（M2型）参与Th2型免疫应答，被认为具有促进肿瘤生成的作用。我们的前期研究证实肝脏内特殊巨噬细胞Kupffer细胞（KCs）对肝癌的发生、发展及侵袭转移起促进作用。晚期肝癌中KCs以M2型为主，清除KCs后肿瘤恶性程度减轻。而对于早期肝癌，清除KCs则影响了M1型巨噬细胞的抗肿瘤、抗感染作用，荷瘤小鼠出现局部脓肿形成、肿瘤生长加速、死亡率上升。本项目以M2型Kupffer细胞为靶细胞，从信号转录和基因调控的角度出发，采用超声靶向微泡破坏技术，多维联合高效抑制肝癌M2型巨噬细胞，对比观察多角度干预M2型KC对小鼠肝癌预后的影响，为利用其治疗肝癌作一些探索性的研究。

巨噬细胞在机体免疫调节、组织修复、炎症反应等方面起着重要作用，肿瘤相关巨噬细胞(TAM)与肿瘤的恶性程度、预后密切相关。研究发现，三氯化钆（GdCl3）能够有效清除巨噬细胞。此外，肝癌组织中高水平的CCL17与肝癌临床病理分级及患者生存率具有相关性， 可能与CCL17促进肝癌干细胞（HCS Cs）的干性，进而增加肿瘤恶性程度有关。在本项研究中，我们利用GdCl3这种TAM特异抑制剂，探索其影响肝癌发展中的实际效果以及CCL17在肝癌发生发展中所起的作用。首先，我们使用一定浓度GdCl3溶液干预小鼠体内肿瘤相关巨噬细胞，通过PCR检测TAM特异标记蛋白基因，结果显示GdCl3干预后，CD206（甘露糖受体I，表达于M2型巨噬细胞）出现明显的下降，差异有统计学意义。另外，我们将MHCC97L细胞分别与M1、M2及CCL17沉默的M2细胞培养，发现其与M2细胞培养时细胞生存、迁移及增殖最强，肿瘤干细胞转录因子表达上调。这些结果说明：GdCl3能够抑制TAM，有可能抑制或延缓肝癌的发展；CCL17能够促进肿瘤细胞上皮间质转化(EMT)，增强其恶性，与患者预后呈负相关，CCL17可能为肝癌治疗提供新的靶点和实验室依据。