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

口腔癌是世界上第六大常见癌症，具有高度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MMP-2的高表达和活性与口腔癌的肿瘤扩张和转移增加有关。因此，MMP抑制剂的潜在效用导致了该领域的重大研究。尽管目前几种可用的抑制剂对MMPs有效，但由于MMPs之间催化活性位点的结构相似性，它们通常对单个MMPs的特异性较低。因此，由于非特异性的MMP抑制作用，使用此类抑制剂的临床癌症试验经历了显著的临床副作用。虽然在转录水平上对MMP-2几乎没有调节，但该酶在MMPs中受到独特的激活过程的影响。MMP-2激活发生在细胞膜相关复合物中，包括膜1型MMPs （MT1-MMPs）、基质金属蛋白酶-2的组织抑制剂（TIMP-2）和proMMP-2。在激活系统中添加过量的可溶性TIMP-2可以抑制MMP-2的激活，这为特异性抑制MMP-2提供了一种可能的新策略。该提议的假设是，可以确定肽阻断TIMP-2和proMMP-2之间的激活复合物的相互作用，从而抑制MMP-2的活性。该实验旨在利用先进的重组蛋白生化和分子生物学方法从随机短肽文库中鉴定抑制剂。具有适当结合特性的肽将被合成并在体外和癌细胞培养系统中进行测试，以确定肽是否抑制MMP-2的激活和活性，进而改变癌细胞的行为。所提出的实验将产生追求长期目标所需的信息，即详细探索MMP-2激活的结构-功能基础，并开发用于治疗口腔癌的新的MMP抑制剂和策略。被称为MMPs的酶可以降解组织，对口腔癌的进展很重要。该研究项目将测试抑制MMPs的新方法。目标是开发用于治疗口腔癌的MMP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.