"A molecular approach toward elucidating the role of the mucin glycocalyx in canc

描述(由申请人提供)：细胞-表面多糖在不同的细胞表面相互作用中扮演着重要的角色，然而糖生物学的研究由于多糖呈递的多样性和动态性质而变得复杂。精确修饰和设计细胞表面多糖的新技术对于深入了解免疫细胞激活、胚胎发育和癌症进展等过程至关重要。糖生物学挑战的一个例证是与膜相关的粘蛋白糖蛋白MUC1。MUC1在大约90%的乳腺癌、卵巢癌、肺癌、结肠癌和胰腺癌中高度过度表达和异常糖基化，是检测上皮组织源性癌症的生物标志物，也是癌症疫苗的靶点。MUC1的研究因其庞大的大小(150-300 kDa)、多态和可变的糖基化模式，以及因为胞内和胞外区域都可以参与影响细胞生存和迁移的信号而变得复杂。人们普遍认为，与癌症相关的粘蛋白可以立体地阻止细胞表面黏附分子进入细胞外基质，并保护癌细胞免受免疫系统的影响；然而，分子证据缺乏，最近的证据表明，它发挥了更复杂的作用。这项拟议的研究试图通过使用一种新的细胞表面工程方法来理解癌症相关粘蛋白过度表达的功能意义，该方法将使糖基化的细微变化与生化作用相关联。一座图书馆 将合成模拟MUc1‘S胞外糖结构域的糖共聚体，附着在膜锚定脂质或工程MUc1蛋白嵌合体上，并在活细胞上展示。使用显微镜和生化方法，我将研究粘蛋白糖基化的变化如何影响整合素聚集、局灶性黏附形成的机械调节，以及对细胞黏附、存活和迁移具有下游影响的信号。这项研究可能导致对糖基化如何影响与癌症进展相关的细胞外基质相互作用的新理解。此外，我们的细胞表面工程方法的发展在研究不同的细胞表面相互作用方面具有强大的应用潜力。总体而言，这种跨学科的方法将结合技术 在聚合物化学和细胞生物学领域，回答仅靠生物学方法无法解决的有关癌症进展的重要问题。

DESCRIPTION (provided by applicant): Cell-surface glycans play essential roles in diverse cell surface interactions, yet glycobiology studies are complicated by the varied and dynamic nature of glycan presentation. New techniques to precisely modify and engineer glycans on the cell surface are of paramount importance for crucial insights into processes such as immune cell activation, embryonic development, and cancer progression. An illustrative example of the glycobiology challenge is the membrane associated mucin glycoprotein MUC1. MUC1 is highly over-expressed and aberrantly glycosylated on ca. 90% of breast, ovarian, lung, colon, and pancreatic carcinomas, is a biomarker for detection of epithelial tissue derived cancers, and is a target for cancer vaccines. MUC1 studies have been complicated by its sheer size (150-300 kDa), polymorphism, variable glycosylation patterns, and because both the cytosolic and extracellular domains can participate in signaling that affects cell survival and migration. There is a widespread assumption that cancer-associated mucins sterically block access of cell surface adhesion molecules to the extracellular matrix and shield cancer cells from the immune system; yet molecular evidence is lacking and recent evidence has suggested more sophisticated roles. The proposed research seeks to understand the functional significance of cancer-associated mucin overexpression by using a new method of cell surface engineering that will enable correlation of subtle changes in glycosylation with biochemical actions. A library of synthetic glycopolymer mimics of MUC1's extracellular glycodomain will be prepared, attached to membrane anchoring lipids or engineered MUC1 protein chimeras, and displayed on live cells. Using microscopic and biochemical methods, I will investigate how changes in the mucin glycocalyx influence mechanical regulation of integrin clustering, focal adhesion formation, and signaling that has downstream effects on cellular adhesion, survival, and migration. This research could lead to a new understanding of how the glycocalyx affects extracellular matrix interactions pertinent to cancer progression. Additionally, development of our cell surface engineering method has strong potential for broad applications in studying diverse cell surface interactions. Overall, this interdisciplinary approach will combine techniques in polymer chemistry and cell biology to answer important questions about cancer progression that cannot be undertaken by biological methods alone.