O-GLYCOSYLATION OF HCG AND CANCER

提出的研究有三个目标，每个目标都有自己的目标。 方法学，但都有一个共同的临床目标-识别和 开发碳水化合物特异性肿瘤标志物，重点是hCG和 滋养层肿瘤的鉴别诊断。 1. O-连接糖单位在妊娠和肿瘤来源的 hCG。 在正常妊娠的尿液池中，12-14%的人 O-连接的糖单元（总共4个）是六糖结构， NeuAc-Gal-GlcNAc-（NeuAc-Gal）-GalNAc-。 相反，试点研究表明， 绒毛膜癌患者尿液中hCG上的结构 受试者（2名检查）和绒毛膜癌细胞的培养基中， 大约50%的六糖结构 唯一发表的研究结果， 这种结构已经出现在癌蛋白上。 为了证实hCG丰富 是绒毛膜癌的标志物，O-连接的结构 另外12-15名受试者的尿液中hCG分子上的糖将被 检查（方法：hCG免疫沉淀，β-消除/标记 O-连接糖单元的色谱分析，与寡糖的色谱分析比较 标准）。 为了确定六糖的丰度是否与 与滋养细胞疾病的发生密切相关， 来自患有更良性的侵袭性/部分/完全性痣的受试者的 接受检查。 非滋养层肿瘤hCG上的O-连接糖单位， 并对其它尿和组织糖蛋白进行检查。 2.滋养层疾病特异性检测方法的研究进展。 虽然 滋养层疾病在美国是罕见的（1500例妊娠中有1例），10 X 在一些非洲和亚洲国家发现的发生率较高。 到 产生疾病特异性测定，β亚基C-末端肽 将分离出绒毛膜癌hCG上含有六糖的细胞， 作为免疫原用于产生绵羊多克隆抗血清， 单克隆抗体方法，并作为凝集素-抗体系统的结构域。 3.正常、肿瘤和诱导或 转化细胞 为了研究这些疾病发生的途径或机制， 蛋白质糖基化的变化伴随癌症，糖基转移酶 将在滋养层外植体培养物中检测活性。 的影响 病毒和化学转化、生长因子等 细胞分化对酶活性的诱导剂/抑制剂将 在适当的情况下，活动变化的动力学方面， 将研究DNA、RNA和蛋白质合成抑制剂的作用。

There are three aims to the proposed research, each with its own methodology but all with a common clinical objective - to identify and develop carbohydrate-specific tumor markers, with emphasis on hCG and the differential diagnosis of trophoblastic neoplasms. 1. Distribution of O-linked sugar units on pregnancy- and tumor-derived hCG. On hCG in pools of urine from normal pregnancy, 12-14% of the O-linked sugar units (4 total) are a hexasaccharide structure, NeuAc-Gal-GlcNAc- (NeuAc-Gal)-GalNAc-. In contrast, pilot studies show that the structure of those on hCG in the urines of choriocarcinoma subjects (2 examined) and in the media from choriocarcinoma cells were around 50% this hexasaccharide structure. The only published findings of this structure have been on cancer proteins. To confirm that hCG abundant in hexasaccharides is a choriocarcinoma marker, the structures of O-linked sugars on hCG molecules in the urines of 12-15 additional subjects will be examined (methods: immunoprecipitation of hCG, beta-elimination/labeling of O-linked sugar units, chromatographic comparison with oligosaccharide standards). To determine if the abundance of hexasaccharide is correlated with the malignance of trophoblastic disease, that on urinary hCG molecules from subjects with the more benign invasive/partial/complete mole will also be examined. O-linked sugar units on hCG from nontrophoblastic neoplasms, and on other urinary and tissue glycoproteins will be examined. 2. Development on trophoblast disease-specific assays. Although trophoblast disease is rare in the U.S.A. (1 in 1500 pregnancies), a 10 X higher occurrence is found in several African and Asian nations. To generate a disease-specific assay, the beta subunit C-terminal peptide containing the hexasaccharides on choriocarcinoma hCG will be isolated and utilized as immunogen for generating sheep polyclonal antisera, for monoclonal antibody approaches, and as domain for a lectin-antibody system. 3. Glycosyltransferase activities in normal, neoplastic, and induced or transformed cells. To investigate the pathways or mechanisms by which changes in protein glycosylation accompany cancer, glycosyltransferase activities will be examined in trophoblast explant cultures. Effects of virus and chemical transformation, growth factors, and other inducers/suppressants of cellular differentiation on enzyme activities will be examined; where appropriate kinetic aspects of activity changes and effects of DNA, RNA and protein synthesis inhibitors will be investigated.