肿瘤相关成纤维细胞促进肝癌恶性行为学的作用和机制研究

Tumor-associated fibroblasts (TAFs) is one of the most important components of tumor microenvironment. It has been reported that TAFs could promote the progression of various solid tumors. Nevertheless, the role of TAFs in hepatocellular carcinoma (HCC) and its regulatory role in liver cancer stem cells (CSC) remains obscure. In previous study, we successfully isolated and purified primary TAFs from human HCC tissues. We found that TAFs-derived cytokines could enhance the malignant behavior of HCC cells and influence the phenotype of liver CSCs. In this project, classic co-culture model, CSC-specific techniques and in vivo imaging system will be used to investigate the role of TAFs in HCCs. Furthermore, high-throughput screening and classic signaling-associated techniques will also be used to identify the TAFs-secreted critical cytokines, which mediated the phenotype change of HCC cells and liver CSCs. The signaling pathway involved in the regulation of HCC cells and liver CSCs by TAFs-secreted critical cytokines will also be investigated. In addition, the correlation between the amount of TAFs, the levels of those critical cytokines, and the activated pathways in HCC with the clinicopathological characteristics and the prognosis of HCCs will be studied in order to identify a novel biomarker for the prognosis of HCCs.

肿瘤相关成纤维细胞（TAFs）是肿瘤微环境的重要组分，已有研究显示TAFs可以调控多种实体肿瘤的进展，但其在肝癌中的作用尚不清楚。项目组前期成功分离了人肝癌组织中的原代TAFs，并发现TAFs分泌的细胞因子可能促进肝癌细胞和肝癌干细胞的恶性生物学行为。本项目将利用经典的共培养模型、肿瘤干细胞研究技术和活体成像系统，深入研究TAFs对肝癌恶性行为学的调控作用。利用高通量筛选结合经典的细胞生物学技术，找到由TAFs分泌的对肝癌细胞和肝癌干细胞具有调控作用的“重要细胞因子”，再结合高通量筛选与信号转导研究技术，探明“重要细胞因子”促进肝癌细胞和肝癌干细胞恶性表型依赖的“关键信号通路”，从而阐明TAFs促进肝癌恶性行为学的机制。通过分析500例肝癌组织中TAFs的数量、“重要细胞因子”的表达水平和“关键信号通路”的活化程度与肝癌临床病理和患者预后的相关性，探讨其作为肝癌预后判断标志物的可行性。

肿瘤相关成纤维细胞（TAFs）是肿瘤微环境的重要组分，研究报道TAFs可以调控多种实体肿瘤的进展，但其在肝癌中的作用尚不清楚。项目组前期成功分离出人肝癌组织中的原代TAFs，并证实与肿瘤旁成纤维细胞（PTFs）相比TAFs有促进肝癌细胞侵袭转移的作用。进一步利用趋化因子芯片筛选出在TAFs和PTFs中差异表达的趋化因子CCL2，CCL5，CCL7和CXCL16。研究结果显示TAFs通过分泌上述4种趋化因子促进肝癌细胞和肝癌干细胞的恶性生物学行为。机制研究发现CCL2和CCL5通过激活hedgehog（Hh）信号通路，而CCL7和CXCL16通过活化HCC中细胞转化生长因子-β（TGF-β）通路活性发挥其促肝癌细胞转移的作用。同时，趋化因子的中和抗体可显著减弱TAFs对肝癌转移的促进作用，并抑制HCC细胞Hh和TGF-β途径的激活。综上所述，TAFs分泌的CCL2、CCL5、CCL7和CXCL16通过对Hh和TGF-β途径的共同激活促进肝癌细胞的转移。本项目明确了TAFs在促进肝癌细胞恶性行为学的作用及分子机制，为肝癌治疗提供了新的靶点。