Investigation of molecular mechanisms of TIMP-1-induced metastasis via shRNA technology

金属蛋白酶组织抑制因子-1(TIMP-1)是一种天然的广谱金属蛋白酶抑制因子，与癌症患者预后不良、生存期短有关。在前两个资助时期，我们可以证明，全身TIMP-1水平的升高不仅增加了肿瘤细胞的内在转移潜能，而且还诱导了肝脏转移前生态位的形成，在那里，中性粒细胞(NGS)充当了增加肝转移的功能介质。我们未发表的数据表明，TIMP-1不仅影响肝脏中NG的动态平衡，还会导致外周血中NG数量的增加。这是有趣的，因为高血NGS被描述为促进特别是肝转移。此外，NGS可以通过分泌细胞因子或蛋白来促进肿瘤转移的局部微环境。因此，在上一个资助期间，我们希望澄清血液中NG数量的增加是否与TIMP-1诱导的肝转移有关，以及TIMP-1在何种水平上对血液和肝脏中NG的动态平衡产生影响。主要问题是：1.TIMP-1诱导血NGS增加的机制是什么？2.NGS在TIMP-1诱导的肝脏转移前生态位中有什么促转移作用？3.肿瘤细胞与血液中NGS的相互作用是否在TIMP-1诱导的肝转移中起作用？从这些结果中，我们期待对局部组织稳态、免疫隔膜和肿瘤细胞之间的相互作用有更深入的了解。这将解释在炎症和癌症进展的背景下关于TIMP-1的临床观察。

Tissue inhibitor of metalloproteinases-1 (TIMP-1), a natural broad spectrum inhibitor of metalloproteinases, is associated with poor prognosis and short survival of cancer patients. In the previous two funding periods we could show that elevated systemic TIMP-1 levels not only increase the tumor cell-intrinsic metastatic potential, but also induce the formation of a pre-metastatic niche in the liver, where neutrophil granulocytes (NGs) act as functional mediators of increased liver metastasis. Our un-published data indicate that TIMP-1 affects NG homeostasis not only in the liver, but also leads to increased NG counts in peripheral blood. This is interesting as high blood NGs are described to promote particularly liver metastasis. Furthermore, NGs can contribute to a pro-metastatic local microenvironment by secreting cytokines or proteases.In the last funding period we would therefore like to clarify whether the increase of NG numbers in the blood contributes to TIMP-1-induced liver metastasis, and at what level TIMP-1 impacts on NG homeostasis in the blood as well as in the liver. The main questions are:1. What is the mechanism of TIMP-1-induced increase of blood NGs?2. What are the pro-metastatic effects of NGs in the TIMP-1-induced pre-metastatic niche in the liver?3. Does interaction of tumor cells with NGs in the blood contribute to TIMP-1-induced liver metastasis?From the results we expect a deeper understanding of the interplay of local tissue homeostasis, the immune compartment, and tumor cells. This will explain clinical observations concerning TIMP-1 in the context of inflammation and cancer progression.