Regulation of MT-MMPs by Trafficking in Cancer Cells

我们的长期目标是确定膜型基质金属蛋白酶（MT-MMPs）如何调节 肿瘤侵袭和转移。虽然基质金属蛋白酶（MMPs）参与了肿瘤的生长， 恶性肿瘤的进展，肿瘤细胞部署这些破坏性蛋白酶的机制 仍然没有解决。MT-MMPs是MMPs的一个亚类，具有能够聚焦的跨膜结构域。 这些酶在质膜上对抗细胞外基质（ECM）屏障，代表了一种新的 肿瘤细胞如何在肿瘤侵袭和转移期间部署蛋白水解活性的范例。我们有 最近证实MT 1-MMP受网格蛋白包被的囊泡内吞作用的调节， 蛋白水解活性。我们确定其胞质结构域是胞吞作用所必需的 并且其去除产生该酶的功能获得性突变体。这种内吞缺陷突变体 在促进前列腺癌细胞的侵袭性方面比野生型MT 1-MMP更有效，这表明 肿瘤细胞的侵袭性可以通过MT-MMPs的运输来调节。使用奇美拉 在MT 1-MMP和MT3-MMP之间，我们获得了第一个证据，即内化的MT-MMP可以是 再循环回到细胞表面。在本申请中，我们建议整合MT 1-MMP和MT3-MMP的研究。 MMP检测肿瘤细胞通过控制MT-1的运输来调节其侵袭性的假设。 MMPs通过其胞质结构域。首先，我们将定义MT 1-MMP和MT3-MMP的贩运 从细胞表面到各种细胞内区室，并表征生长因子的影响， 细胞外基质对其运输的影响。其次，我们将定义MT 1 - 3细胞质结构域的作用。 MMP和MT3-MMP介导它们的运输/再循环，并表征它们与细胞的相互作用。 件.第三，我们将明确运输对MT 1-MMP和MT3-MMP介导的调节作用。 细胞在三维I型胶原基质内或通过三维I型胶原基质生长和侵袭。从这些 这些方法可能有助于了解肿瘤细胞是如何通过调节肿瘤细胞的生长和侵袭优势的。 MT-MMPs的运输和这样的见解可能导致开发用于治疗的新药， 癌症的化学预防

Our long term objective is to determine how membrane-type matrix metalloproteinases (MT-MMPs) regulate tumor invasion and metastasis. Although matrix metalloproteinases (MMPs) have been implicated in the progression of malignant cancer, the mechanism by which tumor cells deploy these destructive proteinases remains unresolved. MT-MMPs are a subset of MMPs with transmembrane domains capable of focusing these enzymes on plasma membrane against extracellular matrix (ECM) barriers, representing a novel paradigm on how tumor cells deploy proteolytic activity during tumor invasion and metastasis. We have recently demonstrated that MT1-MMP is regulated by endocytosis in clathrin- coated vesicles to control its proteolytic activity on cell surface. We established that its cytoplasmic domain is required for endocytosis and its removal gave rise to a gain-of-function mutant of this enzyme. This endocytosis-deficient mutant is more potent than wild type MT1-MMP in promoting invasiveness in prostate cancer cells, suggesting that the invasiveness of tumor cells can be regulated through the trafficking of MT-MMPs. Employing a chimera between MT1-MMP and MT3-MMP, we obtained the first evidence that internalized MT-MMPs can be recycled back to cell surface. In this application, we propose to integrate the studies of MT1-MMP and MT3- MMP to test the hypothesis that tumor cells modulate their invasiveness by controlling the trafficking of MT- MMPs through their cytoplasmic domains. First, we will define the trafficking of MT1-MMP and MT3-MMP from cell surface to various intracellular compartmetns and characterize the impact of growth factors and extracellular matrix on their trafficking. Secondly, we will define the role of cytoplasmic domains of MT1- MMP and MT3-MMP in mediating their trafficking/recycling and characterize their interactions with cellular components. Thirdly, we will define the regulatory role of trafficking on MT1-MMP and MT3-MMP mediated cell growth and invasion within or through 3-dimensional type I collagen matrix. Results from these approaches may yield insights on how tumor cells gain a growth and invasive advantage by regulating the trafficking of MT-MMPs and such insights may lead to the development of novel drugs for therapy and chemoprevention against cancer.