METASTATIS: BIOLOGICAL PHENOTYPE AND MODELS FOR THERAPY

从两个肿瘤进展的早期和晚期分离的细胞 人类不同胚胎学来源的恶性肿瘤，结直肠癌 和黑色素瘤，一直保存在组织培养中，用于免疫， 生物学和分子研究。拟议的研究旨在 为了从实验上剖析转移级联的顺序步骤， 即基底膜的附着和侵入，以及存活和 传播期间和传播后的增长。我们的工作假设是 原发病变的恶性细胞至少需要两种特性才能 进展到转移性表型：侵袭性，即 在营养耗竭的生长条件下以克隆密度生存和增殖 条件。我们的实验模型将是从 体外侵袭性原发非侵袭性病变的重建 无瘤裸小鼠的基底膜模型和体内实验。我们还有 从原发和转移建立的可用的细胞系 相同患者的病变。这些是自发的和实验的 派生的模型将为比较分析 金属蛋白酶和丝氨酸等蛋白水解酶的活性 蛋白水解酶及其与特定抑制剂的相互作用。内生性 生长因子，包括成纤维细胞生长因子和转化生长因子 因素，可能不仅是导致生长自主性转移的原因 但也可能通过激活细胞在侵袭中发挥调节作用 蛋白水解酶或酶抑制剂。 用单抗阻断肿瘤细胞与底物的黏附 抗体(单抗)可以有效地阻断转移级联反应。这个 神经节苷脂GD2和GD3的单抗阻断附着和 转移细胞在组织培养中的侵袭并抑制转移 肿瘤细胞在裸鼠模型中的扩散将被探索。一个新的阶层 利用单抗确定的基底膜相关抗原 神经节苷脂作为依附的受体，从而可能构成 转移细胞的附着因子。生化的，功能性的 分析与附着和入侵有关的抗原将有助于 确定侵袭性和免疫性的常见生物学和免疫学特性 转移性肿瘤细胞的体内外临床前研究 癌症患者治疗方法的发展。

Cells isolated from early and advanced stages of tumor progression of two human malignancies of different embryological origin, colorectal carcinoma and melanoma, have been maintained in tissue culture for immunological, biological, and molecular investigations. The proposed studies are intended to experimentally dissect the sequential steps of the metastatic cascade, i.e., attachment to and invasion of basement membranes, and survival and growth during and after dissemination. Our working hypothesis is that malignant cells from primary lesions require at least two properties for progression to the metastatic phenotype: invasiveness, i,e. the ability to survive and proliferate at clonal densities under nutrient-depleted growth conditions. Our experimental models will be cell variants selected from primary, non-invasive lesions that are invasive in vitro in reconstructed basement membrane models and in vivo in athymic nude mice. We also have cell lines available that were established from primary and metastatic lesions of the same patients. These spontaneously and experimentally derived models will provide the basis for a comparative analysis of the activity of proteolytic enzymes such as metalloproteinases and serine proteinases and of their interactions with specific inhibitors. Endogenous growth factors, including fibroblast growth factors and transforming growth factors, may not only be responsible for growth autonomy of metastatic cells but might also exert a regulatory role in invasion by activating either proteolytic enzymes or enzyme inhibitors. Blocking the attachment of tumor cells to substrate with monoclonal antibodies (MAbs) can effectively disrupt the metastatic cascade. The mechanisms by which MAbs to gangliosides GD2 and GD3 block attachment and invasion of metastatic cells in tissue culture and also inhibit metastatic tumor cell spread in the nude mouse model will be explored. A new class of basement membrane-related antigens as defined with MAbs mi utilize gangliosides as receptors for attachment and thereby may constitute attachment factors for metastasizing cells. The biochemical, and functional analysis of antigens involved in attachment and invasion will help to identify common biological and immunological properties of invasive and metastatic tumor cells in vitro and in vivo as a preclinical study for the development of therapeutic approaches in cancer patients.