巨噬细胞移动抑制因子在肝细胞癌侵袭转移中的作用及机制

Invasion and metastasis is the root cause of treatment failure in hepatocellular carcinoma (HCC) patients. Our preliminary study showed that the expression level of macrophage migration inhibitory factor (MIF) was significantly higher in HCC cells with highly metastatic potential than those with lowly metastatic potential, and MIF knockdown could inhibit the invasion and metastasis of HCC cells via decreasing the level of matrix metalloproteinases (MMPs) and vascular endothelial growth factor (VEGF) in tumor microenvironment. It is indicated that MIF is associated with the invasion and metastasis ability of HCC cells. Therefore, we hypothesize that MIF interacting with tumor microenvironment could regulate the invasiveness ans metastasis of HCC cells. In the current study, the role of MIF played in HCC invasion and metastasis will be determined by MIF supression and overexpression in HCC cells with different metastasis potentials. And small molecule inhibitors of key kinases will be employed to identify MIF-dependent signaling pathways involed in the progress. Moreover, the changes of tumor microenvironment, such as tumor associcated macrophages and tumor infiltrating lymphocytes, induced by MIF expression levels, will be analyzed to explore the potential mechanism of HCC invasion and metastasis, which may provide a novel therapeutic target and gain new insights into the prevention of HCC invasion and metastasis.

侵袭转移是导致肝细胞癌（HCC）患者治疗失败的根本原因。我们前期研究发现，高转移潜能HCC细胞株高表达巨噬细胞移动抑制因子（MIF），下调MIF表达可抑制HCC细胞侵袭转移，提示MIF与HCC的侵袭转移能力密切相关，且可能是通过下调肿瘤微环境中基质金属蛋白酶（MMPs）和血管内皮生长因子（VEGF）的水平发挥作用；据此，我们推测"MIF可能通过与肿瘤微环境相互作用调控HCC的侵袭转移"。本课题拟在细胞水平和动物水平，通过调控不同转移潜能人HCC细胞株中MIF的表达水平，检测其对HCC细胞侵袭转移能力的影响，并筛选MIF依赖的主要信号传导通路；通过分析MIF表达水平变化诱导肿瘤微环境（包括肿瘤相关巨噬细胞和肿瘤浸润淋巴细胞等）的改变，探讨MIF与肿瘤微环境相互作用影响HCC侵袭转移的机制，为防治HCC侵袭转移提供新靶点和新思路。

侵袭转移是导致肝细胞癌（HCC）患者治疗失败的根本原因。我们前期研究发现，高转移潜能HCC细胞株高表达巨噬细胞移动抑制因子（MIF），下调MIF表达可抑制HCC细胞侵袭转移，提示MIF与HCC的侵袭转移能力密切相关。.本课题采用过表达技术，建立稳定高表达MIF的MHCC97L细胞株，检测其体外增殖、侵袭迁移能力变化，结果发现：MIF过表达可显著增强MHCC97L细胞的侵袭迁移能力，而对其增殖能力无明显影响；采用基因沉默技术，建立稳定低表达MIF的HCCLM9细胞株，检测其体外增殖、侵袭迁移能力变化，结果发现：MIF低表达可显著降低HCCLM9细胞的侵袭迁移能力，而对其增殖能力无明显影响；为探索MIF促进HCC细胞侵袭迁移的机制，采用Intracellular signaling array检测HCCLM9细胞内信号通路关键信号分子的变化，结果发现：MIF下调抑制HCCML9细胞侵袭迁移能力是通过p38 MAPKs信号通路实现的。建立HCC原位移植瘤模型，检测MIF对HCC细胞体内侵袭转移能力的影响，结果发现：MIF表达下调可显著抑制肿瘤生长及肺转移的发生，可能是通过抑制血管生成（VEGF）及MMP-9的分泌发挥作用。在组织标本水平，发现MIF蛋白表达水平与HCC术后的转移复发相关，并可能因此而影响了HCC患者的预后，可能成为预测HCC术后转移复发的新指标。进一步采用基于基因表达谱芯片的Ssignaling pathway array技术，解析MIF发挥作用的下游信号通路，结果发现：与阴性对照组NC相比，过表达组OE细胞上调基因数为529，下调基因数为428，有待进一步验证。.本课题通过研究，明确了MIF与HCC细胞侵袭转移能力的正性相关关系，初步阐释了MIF促进HCC细胞侵袭转移的分子机制，为HCC侵袭转移的防治提供新思路和新靶点。