INHIBITION OF CELL-MEDIATED PROMMP-2 ACTIVATION IN ORAL CANCER

描述(申请人提供)：口腔癌是世界上第六大常见癌症，具有高局部侵袭性和高转移率的特点。基质金属蛋白酶(MMPs)家族成员基质金属蛋白酶-2的高水平表达和活性与口腔癌的肿瘤扩大和转移密切相关。因此，基质金属蛋白酶抑制剂的潜在用途导致了这一领域的重大研究。虽然目前已有的几种抑制剂对MMPs是有效的，但由于MMPs之间催化活性部位的结构相似，它们对单个MMPs的特异性一般较低。因此，使用这种抑制剂的临床癌症试验已经经历了由于非特异性的基质金属蛋白酶抑制而产生的显著的临床副作用。虽然在转录水平上对基质金属蛋白酶-2的调控很少，但这种酶在基质金属蛋白酶中经历了一个独特的激活过程。基质金属蛋白酶-2的激活发生在细胞膜相关的复合体中，包括膜类型1的基质金属蛋白酶(MT1-MMPs)、基质金属蛋白酶组织抑制因子-2(TIMP-2)和原基质金属蛋白酶-2。在激活系统中加入过量的可溶性TIMP-2可抑制基质金属蛋白酶-2的激活，这可能是一种针对特定基质金属蛋白酶-2的抑制的新策略。这一设想的假设是，可以识别出可以阻断TIMP-2和ProMMP2之间激活复合体中相互作用的多肽，从而抑制MMP2的活性。这些实验旨在使用先进的重组蛋白质、生物化学和分子生物学方法，从短肽的随机库中识别抑制剂。具有合适结合特性的多肽将被合成并在体外和癌细胞培养系统中进行测试，以确定这些多肽是否抑制了基质金属蛋白酶-2的激活和活性，进而改变了癌细胞的行为。这些拟议的实验将产生实现长期目标所需的信息，即详细探索基质金属蛋白酶-2激活的结构-功能基础，并开发用于口腔癌治疗的新的基质金属蛋白酶抑制剂和策略。被称为MMPs的酶可以降解组织，对口腔癌的进展非常重要。这项研究项目将测试抑制MMPs的新方法。其目标是开发治疗口腔癌的基质金属蛋白酶抑制剂。

DESCRIPTION (provided by applicant): Oral cancer is the sixth most common cancer in the world and characterized by a high degree of local invasiveness and a high rate of metastasis. High level expression and activity of MMP-2, a member of the family of matrix metalloproteinases (MMPs), has been associated with increased tumor expansion and metastasis of oral cancers. The potential utility of MMP inhibitors has therefore lead to significant research in the area. Although several currently available inhibitors are efficient on MMPs, they generally have low specificity for individual MMPs due to the structural similarity of the catalytically active sites among the MMPs. Consequently, clinical cancer trials with such inhibitors have experienced significant clinical side effects due to the non-specific MMP inhibition. While there is little regulation of MMP-2 at the transcriptional level, this enzyme is subject to a unique activation process among the MMPs. MMP-2 activation occurs in a cell membrane-associated complex involving membrane type 1 MMPs (MT1-MMPs), tissue inhibitor of matrix metalloproteinase-2 (TIMP-2), and proMMP-2. That addition of excess soluble TIMP-2 added to the activation system inhibits MMP-2 activation points to a possible novel strategy for specific MMP-2 inhibition. The hypothesis of this proposal is that peptides may be identified which block interactions in the activation complex between TIMP-2 and proMMP-2 and thereby inhibit the MMP-2 activities. The experiments are designed to use advanced recombinant protein biochemical and molecular biological approaches to identify inhibitors from random libraries of short peptides. Peptides with the appropriate binding characteristics will be synthesized and tested in vitro and in a cancer cell culture system to determine whether the peptides inhibit the MMP-2 activation and activity, and in turn alter cancer cell behavior. The proposed experiments will generate the information required to pursue the long-term goal which is to explore in detail the structure-function basis of MMP-2 activation and to develop new MMP inhibitors and strategies for use in treatment of oral cancer. Enzymes called MMPs can degrade tissues and are important for progression of oral cancer. This research project will test new approaches to inhibit MMPs. The goal is to develop MMP inhibitors for treatment of oral cancer.