ROLE OF COLLAGENOLYTIC METALLOPROTEINASES IN METASTASES

为了研究基质金属蛋白酶（MMP）在肿瘤细胞中的作用， 肿瘤的侵袭和转移，我们关注的是多层次的 这些酶的调节。 研究表明，与 MMP酶家族的其他成员，72 kDa明胶酶A水平是 增加的TGF β 1，不受肿瘤促进 佛波醇酯，并且在结肠直肠，乳腺，甲状腺， 卵巢和膀胱肿瘤组织与邻近正常组织相比 粘膜组织 我们已经确定了一种细胞激活机制， 是细胞表面相关的，对72 kDa明胶酶A具有特异性 酶，并且其可以通过用佛波醇酯或 伴刀豆球蛋白A 这种细胞激活机制不影响其他细胞。 胶原酶基因家族的成员。 这种激活机制似乎 需要明胶酶A的细胞表面结合， 鉴定了一种假定的明胶酶A受体。 我们已经研究了潜在酶TIMP-2复合物的结构， 酶缺失突变体和酶抑制剂交联的产生 问题研究 这些研究表明，72 kDa明胶酶A具有在 至少两个TIMP-2结合结构域。 主要结合域位于 在C-末端，血红素样结构域的酶。 该结合位点 是以潜在酶的形式存在的。 第二个结合位点位于 酶活性位点，只有在有机汞 介导的酶激活。 最后，针对92 kDa明胶酶B， 间质胶原酶、溶基质素-1和溶基质素-2已经被 制备和表征。

In order to investigate the role of matrix metalloproteinases (MMP) in tumor invasion and metastases, we have focused on the multilevel regulation of these enzymes. Studies have shown that in contrast with other members of the MMP enzyme family, 72 kDa gelatinase A levels are increased in response to TGFbeta1, are unaffected by the tumor promoting phorbol esters, and show elevated levels in colorectal, breast, thyroid, ovarian and bladder tumor tissues when compared with adjacent normal mucosa tissues. We have identified a cellular activation mechanism which is cell surface associated and specific for the 72 kDa gelatinase A enzyme, and which can be induced by pretreatment with phorbol esters or concanavalin A. This cellular activation mechanism does not affect other members of the collagenase gene family. This activation mechanism appears to require cell surface binding of the gelatinase A enzyme, and we have identified a putative gelatinase A receptor. We have studied the structure of the latent enzyme TIMP-2 complex through production of enzyme deletion mutants and enzyme inhibitor cross linking studies. These studies demonstrate that the 72 kDa gelatinase A has at least two TIMP-2 binding domains. The principal binding domain is located in the C-terminal, hemopexin-like domain of the enzyme. This binding site is available in the latent enzyme form. The second binding site is at the enzyme active site and only becomes available following organomercurial mediated enzyme activation. Finally, antipeptide antibodies against the 92 kDa gelatinase B, interstitial collagenase, stromelysin-1 and stromelysin-2 have been prepared and characterized.