STRUCTURE AND BIOSYNTHESIS OF SELECTIN LIGANDS

这项建议的主要目标是阐明结构和 选择素配体的生物合成及其碳水化合物的作用 肿瘤细胞黏附和转移中的相互作用。在过去几年里， 我们在这一领域取得了重大进展。首先，我们发现高度的 转移性结肠癌细胞对E-选择素的粘附力强于 低转移性对应物。第二，这种肿瘤细胞的黏附可以 被含唾液酸法的重组糖蛋白抑制。第三，我们 证明整体转移唾液酸法转移低聚糖 与E-选择素的粘附性。此外，我们 已经克隆了核心2和Iβ-16-N-乙酰氨基葡萄糖转移酶和 聚唾液酸基转移酶，在表达克隆方面获得了重要的专业知识。 根据这些研究结果，提出了以下三个主要方面： 1.小鼠体内选择素配体的阐明及其调控 通过基因转移获得配基。我们将阐明小鼠的中性粒细胞 低聚糖，因此是小鼠选择素的配体。此外，调制 糖基转移酶基因转移形成唾液酸法和唾液酸法 与E-选择素和P-选择素的黏附相关。 2.L-选择素配体的分子鉴定我们将确定是否 磺基唾液酸法实现L-选择素介导的黏附。我们还将克隆 编码磺基转移酶的cdna，形成磺基唾液酸赖氨酸，推测是L- 选择素配体。 3.糖类在肿瘤转移中的作用。我们将确定是否有唾液。 Lex(和sialyl Lea)在血源性肿瘤转移中起重要作用。 这些研究还将扩大到确定寡糖是否 结构在肿瘤转移中起着至关重要的作用。 这些研究将使我们了解其结构和生物合成 选择素配体及其在肿瘤中的作用 转移。

The primary objective of this proposal is to elucidate the structures and biosynthesis of selectin ligands, and the roles of selectin-carbohydrate interaction in tumor cell adhesion and metastasis. In the past few years, we have made critical progress in this field. First, we found that highly metastatic colonic carcinoma cells adhere more strongly to E-selectin than low metastatic counterparts. Second, such tumor cell adhesion can be inhibited by sialyl LeX-containing recombinant glycoproteins. Third, we demonstrated that en bloc transfer sialyl LeX oligosaccharide transferred on the cell surface results in adhesion to E-selectin. In addition, we have cloned the core 2 and I beta-16-N-acetylglucosaminyltransferases and polysialyltransferase, gaining significant expertise in expression cloning. Based on these findings, three major areas are proposed as follows: 1. Elucidation of selectin ligands in mice and modulation of selectin ligand by gene transfer. We will elucidate the mouse neutrophil oligosaccharides, thus mouse selectin ligands. In addition, modulation of sialyl LeX and sialyl Lea formation by glycosyltransferase gene transfer is correlated with adhesion to E- and P-selectin. 2. Molecular Identification of L-selectin ligands. We will determine if sulfo sialyl LeX achieves L-selectin-mediated adhesion. We will also clone cDNA encoding a sulfotransferase that forms sulfo sialyl LeX, a putative L- selectin ligand. 3. Roles of carbohydrates in tumor metastasis. We will determne if sialyl LeX (and sialyl Lea plays a major role in blood-borne tumor metastasis. The studies will also be extended to determine if oligosaccharide structures play a critical role in tumor metastasis. These studies will allow us to understand the structure and biosynthesis of selectin ligands and the roles selectin-mediated adhesion in tumor metastasis.