Mechanistic Analysis of TIMP-1 Induction of EMT

描述(申请人提供)：基质金属蛋白酶组织抑制因子-1(TIMP-1)通常被认为是通过阻断基质金属蛋白酶(MMPs)的降解活性来抑制恶性表型的作用。然而，最近的临床观察表明，TIMP-1在大多数肿瘤中过表达，且往往与预后不良有关，提示TIMP可能具有促癌作用。TIMP-1可诱导MCF10A乳腺上皮细胞发生上皮间充质转化(EMT)，这是导致肿瘤转移的第一步。这些研究的目的是确定TIMP-1能够诱导EMT的机制，并提供关于TIMP-1替代促癌活性的重要信息。我们将使用一个可诱导的载体系统来过表达TIMP-1，以评估其在调节转化生长因子-β信号转导过程中的潜在作用。此外，还将通过siRNA技术评估PAI-1在TIMP-1介导的EMT中的潜在作用和必要性。最后，这些体外观察将与临床数据相关联，以评估TIMP-1、E-钙粘蛋白、β-连环蛋白、PAI-1与乳腺癌患者预后和死亡率的潜在相关性。

DESCRIPTION (provided by applicant): Tissue Inhibitor of Matrix Metalloproteinase-1 (TIMP-1) is commonly believed to function as an inhibitor of the malignant phenotype by blocking the degradative activity of Matrix Metalloproteinases (MMPs). However, recent clinical observations have demonstrated that TIMP-1 is overexpressed in a majority of tumors and is often associated with a poor prognosis, suggesting that TIMPs may possess a pro-malignant function. TIMP-1 is able to induce Epithelial to Mesenchymal Transition (EMT) in MCF10A breast epithelial cells, an initial step leading to metastasis. The goals of these studies are to determine the mechanism by which TIMP-1 is able to induce EMT and provide important information about the alternative pro-malignant activity of TIMP-1. An inducible vector system will be used to overexpress TIMP-1 to assess its potential role in regulating TGF-Beta signaling, an important mediator of EMT. In addition, studies will be performed to assess the potential role and necessity of PAI-1 in TIMP-1 mediated EMT through siRNA techniques. Finally, these in vitro observations will be related to clinical data to assess potential correlations between TIMP-1, E-cadherin, Beta-catenin, PAI-1 and prognosis and mortality of breast carcinoma patients.