PROTEOGLYCAN INFLUENCE ON MAMMARY CELL DIFFERENTIATION

本研究的目的是明确基底膜的作用， 蛋白多糖在乳腺上皮细胞调控中的作用 分化 它们对细胞附着和形态的影响将 也被研究。 从长远来看，预计调查 将有助于更好地全面了解地下室的作用 膜在分化和发育中的作用。 此外，研究 这将有助于确定蛋白聚糖的一些未知功能， 上皮组织，并揭示了这些组织的一些基本功能， 无处不在的分子 将使用小鼠乳腺上皮细胞培养物进行实验 从晚期妊娠小鼠和最近分离的小鼠中分离的细胞 乳腺上皮细胞株COMMA-1-D。 当培养在合适的 基质，即浮动胶原蛋白（I型）凝胶，细胞合成 许多牛奶蛋白质，也组装一个独特的基膜。 因此 它们构成了可以容易地调节的实验系统。 将采取三种办法解决这一问题： 1.对硝基苯基-β-木糖苷，一种高度特异性的蛋白聚糖抑制剂 合成将用于干扰蛋白聚糖和糖胺聚糖 代谢和细胞分化的相应变化 通过跟踪乳蛋白合成来监测。 2.将在纯化的蛋白聚糖和蛋白聚糖上培养细胞 与其他基底膜成分（而不是基质基质）复合 组件）。 他们的影响将再次通过检查牛奶来评估 蛋白质合成 3.将针对纯化的基底产生单克隆抗体 膜蛋白聚糖，并将用于免疫细胞化学实验 研究基底膜蛋白多糖与细胞凋亡的关系， 组成和上皮细胞分化的发展腺体 本身 希望本研究能对一些基本的机制有所帮助 控制细胞分化和细胞生理学。 但 这些信息对于肿瘤生物学也是重要， 糖胺聚糖的代谢和细胞分化 经常发生在肿瘤的发展过程中。 不管这两个参数 在正常的细胞过程中是相互关联的，因此可能是 对肿瘤生物学有很大的兴趣。

The objectives of this study are to define the roles of basement membrane proteoglycans in the regulation of mammary epithelial cell differentiation. Their influence on cell attachment and morphology will also be studied. In the long term it is expected that the investigations will contribute to a better general understanding of the role of basement membranes in differentiation and development. In addition, the study should help define some of the unknown functions of proteoglycans in epithelial tissue, and reveal some of the basic functions of these ubiquitous molecules. Experiments will be carried out using cultures of mouse mammary epithelial cells isolated from late pregnant mice and a recently isolated mouse mammary epithelial cell line, COMMA-1-D. When cultured on a suitable substratum, namely floating collagen (type I) gels, the cells synthesise many milk proteins and also assemble a distinct basement membrane. As such they constitute an experimental system that can be readily modulated. Three approaches to the problem will be pursued: 1. p-Nitrophenyl-Beta-xyloside, a highly specific inhibitor of proteoglycan synthesis will be used to perturb proteoglycan and glycosaminoglycan metabolism and the consequential changes in cellular differentiation monitored by following milk protein synthesis. 2. Cells will be cultured on purified proteoglycans and on proteoglycans complexed to other basement membrane components (rather than stromal matrix components). Again their effects will be assessed by examining milk protein synthesis. 3. Monoclonal antibodies will be produced against purified basement membrane proteoglycans and will be used in immunocytochemical experiments to study the relationship between basement membrane proteoglycan composition and epithelial cell differentiation in the developing gland itself. It is expected that this study will shed light on some basic mechanisms controlling cell differentiation and cell physiology. However, the information should also be important for tumor biology in that alterations of glycosaminoglycan metabolism and cellular differentiation both frequently occur in tumor development. Whether or not these two parameters are interrelated in normal cellular processes is thus likely to be of considerable interest to tumor biology.