NMR Group Project: Preparation and Properties of Novel M

NMR 课题组项目：Novel M 的制备及性能

• 批准号: 7338768
• 负责人: Joseph John Barchi
• 金额: --
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7338768
• 关键词: NMR; Group; Project; Preparation; Properties

An established hallmark of tumorigenesis is the biosynthesis of aberrant glycan chains due to changes in the expression of glycoprocessing enzymes in tumor tissue. These aberrations become more marked as the tumor acquires a more aggressive phenotype. Tumor cell-surface carbohydrates play important roles in the motility and metastasis of many different cancer cells. In addition, many of these aberrant glycans are tumor-associated carbohydrate antigens (TACA) and have been used in the development of tumor vaccines. Since most of the cellular interactions with TACA's are not well understood, there is an urgent need to better characterize the specific molecular interactions that occur during these events. One feature of carbohydrate binding to macromolecules that is well understood is the concept of multivalency: Monomer carbohydrates bind to proteins very weakly while "clustering" of a monomer raises this affinity as much as a million-fold. We have prepared the important Thomsen-Friedenreich (Tf) antigen (Gal(beta)1-3GalNAc(alpha)-O-Ser/Thr) on very specific templates to take advantage of this so-called "cluster glycoside effect". As mentioned in the last report, we have prepared gold self-assembled nanospheres and quantum dots containing sugar derivative and reported preliminary details on their function. The in vivo experiments with our gold nanospheres in mice were repeated twice with varying results. However, these were caused by the use of a tumor cells that had had a different genetic makeup than the original and an error in the amount of tumor used. We have done further in vitro characterization of the gold particles and found them to act differently than monovalent sugar molecules. A large in vivo study has yielded conflicting but highly provocative results with varying concentrations of particles being tested against control (linker-only) nanoparticles. We seem to be able to inhibit primary tumor growth in vivo, but we possibly promote metastasis with particles of larger hydrodynamic volume. In the last report we reported synthesis of mucin glycopeptides and developed new linker technology to attach these to gold particles. Synthesis of gold particles with 2 glycopeptides has been achieved and characterization is in full swing. Preliminary in vitro testing showed funcytional sugar untis on the gold particles. In our quantum dots (qdots) work, we showed that contain Tf antigen-containing Qdots are functional but we needed to develop technology that removed the negative charge on our original design. WE now feel that our qdots may be more stable than commercial qdots since ours do not precipitate on size exclusion membranes during concentration experiments. We are scaling up our process and will supply several collaborators with material for labeling studies. We are very excited about the prospects for both families of particles that are being developed.

肿瘤发生的一个既定标志是由于肿瘤组织中糖加工酶表达的变化而生物合成异常聚糖链。当肿瘤获得更具侵袭性的表型时，这些畸变变得更加明显。肿瘤细胞表面碳水化合物在许多不同癌细胞的运动和转移中发挥重要作用。此外，许多异常聚糖是肿瘤相关糖抗原（TACA），已用于肿瘤疫苗的开发。由于大多数细胞与 TACA 的相互作用尚不清楚，因此迫切需要更好地表征这些事件期间发生的特定分子相互作用。碳水化合物与大分子结合的一个众所周知的特征是多价概念：单体碳水化合物与蛋白质的结合非常弱，而单体的“聚集”则将这种亲和力提高了数百万倍。我们在非常特异的模板上制备了重要的 Thomsen-Friedenreich (Tf) 抗原（Gal(beta)1-3GalNAc(alpha)-O-Ser/Thr），以利用这种所谓的“簇糖苷效应”。正如上一篇报告中提到的，我们制备了金自组装纳米球和含有糖衍生物的量子点，并报告了其功能的初步细节。我们的金纳米球在小鼠体内的体内实验重复了两次，结果各不相同。然而，这些都是由于使用的肿瘤细胞的基因组成与原始细胞不同以及肿瘤细胞用量的错误造成的。我们对金颗粒进行了进一步的体外表征，发现它们的作用与单价糖分子不同。一项大型体内研究产生了相互矛盾但极具争议性的结果，其中针对对照（仅连接体）纳米粒子测试了不同浓度的粒子。我们似乎能够抑制体内原发性肿瘤的生长，但我们可能会用较大流体动力学体积的颗粒促进转移。在上一份报告中，我们报道了粘蛋白糖肽的合成，并开发了新的连接技术将其附着到金颗粒上。已实现金颗粒与2种糖肽的合成，表征工作正在紧锣密鼓地进行中。初步体外测试显示金颗粒上存在功能性糖。在我们的量子点 (qdot) 工作中，我们证明含有 Tf 抗原的 Qdot 是有功能的，但我们需要开发技术来消除我们原始设计上的负电荷。我们现在认为我们的量子点可能比商业量子点更稳定，因为我们的量子点在浓度实验期间不会沉淀在尺寸排阻膜上。我们正在扩大我们的流程，并将向一些合作者提供用于标签研究的材料。我们对正在开发的这两个粒子家族的前景感到非常兴奋。