ENDOGENOUS LAMININ EXPRESSION AND METASTASIS

层粘连蛋白是一种发现于基底膜的高相对分子质量糖蛋白， 已被证明可以调节几种类型的细胞与 基底膜(IV型)胶原。我们的初步研究表明， 内源性层粘连蛋白样蛋白的表达与 小鼠肿瘤细胞表面物质与转移潜能。 据推测，这种物质的表达有助于 转移，可能是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 有证据表明，细胞表面层粘连蛋白的表达有助于 转移潜能。将使用两种方法来实现这一点。在 第一种方法，我们将检查未克隆的异种小鼠肿瘤 细胞表面层粘连蛋白的表达差异 建立层粘连蛋白阳性和缺陷层粘连蛋白细胞系 人口。将使用三种方法来实现这一点。这些措施包括： (1)亲和纯化的补体介导的细胞毒作用 抗层粘连蛋白抗体；(2)流式细胞术；(3)胶原附着。 用这些方法分离的层粘连蛋白阳性和缺陷层粘连蛋白细胞系 然后，我们将比较这两种方法的致瘤性和转移性。 队形。在第二种方法中，我们将外源层粘连蛋白添加到 层粘连蛋白缺乏的细胞。然后将层粘连蛋白处理过的细胞进行比较 与未经处理的对照细胞在体内的行为。这个 这项研究的意义在于它将为 确定表达或细胞表面层叠是否存在的证据 肿瘤细胞的致癌性有助于其恶变的可能性。(A)

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)