CRYPT CELL ANTIGENS AS MARKERS FOR COLON CANCER

我们实验室目前的研究已经确定了一组7 抗刷状缘膜单克隆抗体 胎儿和新生大鼠肠细胞的组成部分， 人结肠肿瘤细胞系CaCo-2，其定义了癌胚 胎儿肠细胞表达的抗原，成人小隐窝 肠细胞以及人和大鼠结肠腺癌。 的 被这些抗体识别的抗原，称为“隐窝细胞” 抗原，已被确定为高分子量 糖蛋白 拟议研究的长期目标 主要有：1）进一步明确这些隐窝细胞的结构 人结肠癌细胞表达的抗原和二甲基 肼（DMH）诱导的大鼠结肠肿瘤; 2）相关， 大鼠模型系统，“隐窝细胞”抗原的表达 具有不同的癌变阶段和组织学特征 3）检测其在不同正常组织中的表达， 和患病的人体组织 本文中描述的大多数研究 建议将集中在使用单克隆抗体和 凝集素作为鉴定细胞和组织中特异性抗原的工具， 免疫荧光染色，并纯化“隐窝细胞” 通过亲和色谱法测定抗原。 纯化的抗原将 通过平板凝胶电泳、蛋白质印迹和 肽图谱 部分氨基酸序列将被 确定，和相关的糖苷链的结构 将研究CaCo-2细胞产生的抗原。 我们的7种单克隆抗体识别 与抗原相关的碳水化合物基团将被 测定 从手术中获得的结肠癌样品 标本，以及邻近和远端的大体正常粘膜将 用于将抗原的分布与各种 原发性肿瘤的组织学特征。 我们还将使用 来自患有家族性息肉病的患者的样本， 志愿者亲属有同样的疾病风险。 这些研究可能 导致了一种测试的发展，这种测试将允许临床医生 预测谁的亲属在风险最终将发展 疾病的表型表现，并有助于以下- 腺瘤性息肉复发的患者中， 结肠，因为他们属于“高风险”组容易发展 结肠癌 总体而言，拟议的研究应提供 关于“地穴”潜在作用的宝贵信息 结肠癌发生中的“细胞”抗原及其作为 结肠癌的组织学和临床标志物。

Current research in our laboratory has identified a group of 7 monoclonal antibodies, produced against brush border membrane components of fetal and newborn rat intestinal cells, and the human colon tumor cell line CaCo-2, which define oncofetal antigens expressed by fetal intestinal cells, adult crypt small intestinal cells, and human and rat colonic adenocarcinomas. The antigens recognized by these antibodies, called "Crypt Cell" antigens, have been identified as high molecular weight glycoproteins. The long term objectives of the proposed research are: 1) To further define the structure of these crypt cell antigens expressed by human colon tumor cells and dimethyl hydrazine (DMH)-induced rat colonic tumors; 2) To correlate, in the rat model system, expression of the "Crypt Cell" antigens with different stages of carcinogenesis and histological features of the tumors; 3) To evaluate their expression in various normal and diseased human tissues. Most studies described in this proposal will be centered on the use of monoclonal antibodies and lectins as tools to identify specific antigens in cells and tissues by immunofluorescence staining, and to purify the "Crypt Cell" antigens by affinity chromatography. The purified antigens will be compared by slab gel electrophoresis, Western blotting and peptide mapping. Partial amino acid sequences will be determined, and the structure of the glycosidic chains associated with the antigens produced by CaCo-2 cells will be investigated. The ability of our 7 monoclonal antibodies to recognize carbohydrate groups associated with the antigens will be determined. Samples of colon cancer obtained from surgical specimens, and of adjacent and distal grossly normal mucosa will be used to correlate the distribution of the antigens to the various histological features of the primary tumors. We will also use specimens from patients suffering from Familial Polyposis and volunteer relatives at risk of the same disease. These studies may lead to the development of a test which would permit clinicians to predict who to the relatives at risk will eventually develop the phenotypic manifestation of the disease, and to aid in the follow- up of patients with recurrent formation of adenomatous polyps in the colon, as they belong to the "high risk" group prone to develop colon carcinoma. Overall, the proposed studies should provide valuable information regarding the potential role of the "Crypt Cell" antigens in colon carcinogenesis, and their use as histological and clinical markers of colon cancer.