肿瘤相关巨噬细胞介导肝癌动脉生成的机制及其在肿瘤进展中的作用

Hepatocellular carcinoma (HCC) derives its blood supply primarily from the hepatic artery. However, the exact role played by tumor arteriogenesis in cancer progression, and the regulation mechanism of tumor arteriogenesis is not clear. In ischemic disease, the collateral ateriogenesis rely on vascular remodeling mediated by macrophage expressing CCR2 and CXCR3. We recently have revealed that a large amount of newly formed arteries exist in HCC, which is very different from normal arteries. We also found that macrophages and CXCR3 expression have a negative correlation with the prognosis of patients. Furthermore, tumor progression could be suppressed through the elimination of macrophages in experimental hepatocellular carcinoma model. In this study, we focus on the following aspects: (1) investigate the relationship between tumor related macrophage expressing CCR2 and CXCR3 and tumor arteriogenesis and outcomes in a prospective corhot of HCC patients; (2)compare the effect of tumor associated macrophages and normal macrophages on vascular smooth muscle cell proliferation, migration and phenotype. Furthermore, we will explore the effect of CCR2 and CXCR3 pathway on the above-mentioned process; (3)applying monocyte/macrophage deficient mice hepatocellular carcinoma model, to clarify the regulatory function of above-mentioned pathways to arteriogenesis through the adoptive transfusion of the gene deficient monocytes respectively; ⑷ in order to demonstrate the role of arteriogenesis in HCC progression, we will compare the effect on tumor progression by either simple blocking angiogenesis or combination of blocking angiogenesis and arteriogenesis. Our results will be helpful to reveal the mechanism of arteriogenesis and provide new ideas for the treatment of HCC..

绝大多数肝癌血供来自动脉。但肝癌动脉生成的调控机制、及其在肿瘤进展中的确切作用尚不清楚。已知在动脉阻塞性疾病中，侧支动脉生成依赖于表达CCR2和CXCR3的巨噬细胞介导的血管壁重构。最近我们观察到:?肝癌中也存在大量的新生动脉，其形态与正常动脉有很大差异；?肿瘤相关巨噬细胞参与了实验性肝癌的动脉生成和肿瘤进展。本课题拟：⑴进一步分析临床肝癌组织标本中的巨噬细胞及相关分子的表达与动脉生成的相关性。⑵比较肿瘤相关巨噬细胞与正常巨噬细胞对血管平滑肌细胞增殖和功能的影响。并探讨CCR2和CXCR3信号通路在该过程中的作用和机制。⑶应用条件性单核/巨噬细胞缺陷小鼠肝癌模型，分别输注上述基因缺陷的单个核细胞，从而阐明上述通路对肿瘤动脉生成及形态的调控作用；⑷联合阻断动脉生成及微血管生成，与单纯阻断微血管生成比较，论证动脉生成在肝癌进展中的作用。本课题有助于揭示肿瘤动脉生成的机制，为治疗肝癌提供新思路。

肝癌动脉生成对肿瘤血供起着重要的作用，揭示动脉生成的调控机制对肿瘤治疗具有十分重要的意义。本课题分别从临床与基础层面，研究了肝癌的动脉生成对肿瘤进展的影响，并深入探讨了动脉生成的机制：①首先通过前瞻性多中心随机对照试验发现：对比于单纯碘油化疗，碘油化疗+明胶海绵栓塞显著的提高了肿瘤坏死率。这表明动脉生成在肝癌的进展中起重要作用，而“去动脉化”可有效导致肿瘤坏死、阻止肝癌的进展；另一项临床研究也证实了术前栓塞化疗可有效阻断肝癌的动脉生成，并可显著提高肝癌患者的临床预后；②其次，我们验证了外周血的单核细胞中CXCR2, CCR2, EP400这三个基因能够准确预测肝癌，初步揭示了肝癌的单核细胞与正常的单核细胞的不同；③开展了肝癌动脉生成血管标记物的研究，结果显示α-SMA、SPARCL1及MEP1A基因有较好的血管共定位表达，可以用来标记肝癌内有动脉功能的血管；④我们进一步对乏血供和富血供的肝癌进行了基因表达差异分析，筛选出了关键基因MEP1A，并通过功能实验证实了MEP1A基因在肝癌发生转移及血管生成中起着重要的作用。总的来说，我们的研究阐明了动脉生成在肝癌进展中的重要意义，探索了肝癌患者单核细胞与正常单核细胞基因表达的不同，并验证了MEP1A基因在肝癌进展及动脉生成中的作用。