Rho Seung Bae, Chung Bo Mee, Lee Je-Ho
Molecular Therapy Research Center, Sungkyunkwan University, Samsung Medical Center Annex 8F, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710, South Korea.
J Cell Biochem. 2007 May 1;101(1):57-67. doi: 10.1002/jcb.21127.
The tissue inhibitors of metalloproteinases (TIMPs) are multifunctional proteins that specifically inhibit matrix metalloproteinases (MMPs) and regulate extracellular matrix (ECM) turnover and tissue remodeling. This is directed by forming tightly bound inhibitory complexes with MMPs. Recent years have revealed important differences of various biological activities between TIMP families but molecular mechanisms are not clear. To define the molecular mechanisms of TIMP-1-dependent biological processes, we used TIMP-1 as bait in a yeast two-hybrid screen, along with a human ovary cDNA library. Further characterization revealed the ninth zinc finger domain as an interacting domain of the promyelocytic leukemia zinc finger protein (PLZF). Interaction of PLZF with TIMP-1 in mammalian cells was also confirmed by co-immunoprecipitation and with in vitro binding assays. We investigated whether TIMP-1-mediated anti-apoptotic activity could promote the growth of ovarian cancer in an experimental model system. TIMP-1 treatment was found to be more effective at increasing ovarian cancer growth when compared with PLZF in parallel experiments. Subsequently, the efficacy of a combined treatment with TIMP-1 and PLZF was investigated. In the presence of both of these proteins, TIMP-1 significantly reduced apoptosis induced by PLZF in cervical carcinoma cells. These combined results indicate that TIMP-1 functions as an anti-activator of the transcriptional repressive activity of PLZF.
金属蛋白酶组织抑制剂（TIMPs）是多功能蛋白质，可特异性抑制基质金属蛋白酶（MMPs），并调节细胞外基质（ECM）周转和组织重塑。这是通过与MMPs形成紧密结合的抑制复合物来实现的。近年来，已揭示出TIMPs家族之间各种生物学活性的重要差异，但分子机制尚不清楚。为了确定TIMP-1依赖性生物学过程的分子机制，我们在酵母双杂交筛选中使用TIMP-1作为诱饵，并结合人卵巢cDNA文库。进一步的表征揭示第九个锌指结构域是早幼粒细胞白血病锌指蛋白（PLZF）的相互作用结构域。PLZF与TIMP-1在哺乳动物细胞中的相互作用也通过共免疫沉淀和体外结合试验得到证实。我们在实验模型系统中研究了TIMP-1介导的抗凋亡活性是否能促进卵巢癌的生长。在平行实验中发现，与PLZF相比，TIMP-1处理在促进卵巢癌生长方面更有效。随后，研究了TIMP-1与PLZF联合治疗的疗效。在这两种蛋白质同时存在的情况下，TIMP-1显著降低了PLZF诱导的宫颈癌细胞凋亡。这些综合结果表明，TIMP-1作为PLZF转录抑制活性的抗激活剂发挥作用。
