EMMPRIN: from biology to molecular mechanism

描述（由申请人提供）：细胞外基质金属蛋白酶诱导剂（EMMPRIN）在多种癌症和炎症性疾病中高度表达，刺激基质金属蛋白酶（MMP）和促炎细胞因子的分泌。EMMPRIN是作为跨膜蛋白存在但以多种未表征形式由细胞释放的独特蛋白质的子集之一。这些细胞外形式已经与至少六种癌症有关，并已被证明有助于癌症进展期间的正反馈循环。因此，识别EMMPRIN的特定细胞外形式，表征这些形式中的每一种如何促进疾病进展，并识别其细胞靶点将显著有助于我们对癌症和炎症的理解。 我们已经采取了一种综合的方法来充分表征EMMPRIN及其在疾病进展中的作用，结合生物学，生物化学和原子分辨率的研究。我们的生物学研究已经在人血液中鉴定了几种细胞外形式的EMMPRIN，并由癌细胞释放，这些形式分泌的特异性MMP/细胞因子将在这里得到充分表征（目的1）。为此，我们已经开发了重组表达系统，生产所有必需的蛋白质。然后，我们将通过利用我们的重组蛋白鉴定这些EMMPRIN形式的细胞靶点，并表征它们的相互作用（目的2）。最后，我们已经开始解决X射线晶体结构和表征视网膜特异性EMMPRIN亚型的溶液行为，这有助于视网膜母细胞瘤，在这里，我们将在生物病理学和生物学上表征这种亚型（目标3）。由于EMMPRIN过度表达导致与多种疾病进展密切相关的整个蛋白质家族失调，我们结合生物学和生物物理学方法将分别在生物学和分子水平上充分表征细胞外EMMPRIN。

DESCRIPTION (provided by applicant): The Extracellular Matrix Metalloproteinase Inducer (EMMPRIN) is highly expressed in multiple cancers and inflammatory disorders where it stimulates secretion of matrix metalloproteinases (MMPs) and pro-inflammatory cytokines. EMMPRIN is amongst a subset of unique proteins that exist as a transmembrane protein but is released by cells in multiple uncharacterized forms. These extracellular forms have already been linked to at least half a dozen cancers and have been shown to contribute to a positive feedback loop during cancer progression. Thus, identifying the specific extracellular forms of EMMPRIN, characterizing how each of these forms contributes to disease progression, and identifying their cellular targets would significantly contribute to our understanding of cancer and inflammation. We have taken an integrative approach to fully characterize EMMPRIN and its role in disease progression by combining biological, biochemical, and atomic resolution studies. Our biological studies have already identified several extracellular forms of EMMPRIN in human blood and released by cancer cells that and the specific MMPs/cytokines secreted by these forms will be fully characterized here (Aim 1). To this end, we have developed recombinant expression systems that produce all the necessary proteins. We will then identify the cellular targets of these EMMPRIN forms by utilizing our recombinant proteins and characterize their interactions (Aim 2). Finally, we have begun solving the X-ray crystal structure and characterizing the solution behavior of a retinal-specific EMMPRIN isoform that contributes to retinoblastoma and here we will characterize this isoform both biophysically and biologically (Aim 3). Since EMMPRIN over-expression results in the deregulation of entire protein families integrally involved in the progression of multiple diseases, our combined biological and biophysical approach will fully characterize extracellular EMMPRIN at the biological and molecular levels, respectively.