ENDOGENOUS LAMININ EXPRESSION AND METASTASIS

层粘连蛋白是一种存在于基底膜中的高分子量糖蛋白， 已经显示出介导几种类型的细胞附着到 基底膜（IV型）胶原。 我们的初步研究显示 内源性层粘连蛋白样蛋白的表达 小鼠肿瘤细胞表面的物质和转移潜力。 假设这种物质的表达有助于 转移，可能通过促进转移细胞的附着 到基底膜。 这项工作的总体目标是提供直接的 有证据表明，细胞表面层粘连蛋白的表达有助于 转移潜能 将使用两种方法来做到这一点。 在 第一种方法，我们将检查未克隆的异质性小鼠肿瘤， 细胞表面层粘连蛋白表达的差异，分离和 从这些细胞中建立层粘连蛋白阳性和层粘连蛋白缺陷细胞系 人口。 将使用三种方法来做到这一点。 这些措施包括： (1)在亲和纯化的补体存在下的补体介导的细胞毒性 抗层粘连蛋白抗体;（2）流式细胞术;（3）胶原附着。 通过这些方法分离的层粘连蛋白阳性和层粘连蛋白缺陷细胞系 然后将在致瘤性和转移性方面进行比较 阵 在第二种方法中，我们将外源性层粘连蛋白加入到细胞中。 层粘连蛋白缺陷细胞。 然后比较层粘连蛋白处理的细胞 与未处理的对照细胞在体内行为方面的差异。 的 这项研究的意义在于，它将提供直接的 确定细胞表面层粘连蛋白的表达是否 肿瘤细胞的恶性程度增加了它们的恶性潜能。 （一）

Laminin, a high molecular weight glycoprotein found in basement membranes, has been shown to mediate the attachment of several types of cells to basement membrane (type IV) collagen. Our preliminary studies have shown a direct correlation between the expression of an endogenous laminin-like substance on the surface of murine tumor cells and metastatic potential. It is hypothesized that the expression of this substance contributes to metastasis, possibly by facilitating attachment of the metastasizing cells to basement membranes. The overall goal of this work is to provide direct evidence to show that the expression of cell surface laminin contributes to metastatic potential. Two approaches will be used to do this. In the first approach we will examine uncloned heterogeneous murine tumors for differences in expression of cell surface laminin, isolating and establishing laminin-positive and laminin-deficient cell lines from these populations. Three methods will be used to do this. These will include: (1)\complement-mediated cytotoxicity in the presence of affinity-purified antilaminin antibodies; (2)\flow cytometry; and (3)\collagen attachment. The laminin-positive and laminin-deficient cell lines isolated by these means will then be compared with regard to tumorigenicity and metastasis formation. In a second approach we will add exogenous laminin to the laminin-deficient cells. The laminin-treated cells will then be compared with untreated control cells with regard to in vivo behavior. The significance of this research lies in the fact that it will provide direct evidence to determine whether or not the expression or cell surface laminin by tumor cells contributes to their potential for malignancy. (A)