PHOSPHATIDYLETHANOLAMINE AND CELL PROLIFERATION

我们研究的长期目标是了解监管机构 乳腺上皮细胞增殖分化机制的研究进展 细胞。培养中的哺乳动物细胞可归类为乙醇胺 (ETN)-响应型和非响应型关于增长 回应。ETN反应型包括正常大鼠乳腺上皮细胞 细胞和一些人和大鼠乳腺癌细胞。ETN-响应性 乳腺细胞系的催乳素反应性似乎是偶联的： 一些乳腺细胞系对这两种药物都有反应，而另一些则是这样 没有回应他们中的任何一个。当ETN反应细胞在 ETN缺乏培养基膜中磷脂酰乙醇胺(PE)含量 磷脂显著减少，表明ETN反应细胞 如果没有外源的，就不能合成或维持足够量的PE ETN，PE缺陷膜不适合正常使用 生物功能。 我们目前的目标是：1)阐明生物化学机制 ETN反应性和2)研究PE缺乏对机体的影响 催乳素作用和细胞代谢的其他方面。ETN响应 和-无反应的大鼠乳腺癌细胞株将用于 学习。 为了实现第一个目标，各种合成和周转过程 将对体育进行检查。其中包括对下列活动的审查： 磷脂酰丝氨酸脱羧酶和将ETN结合到PE中的酶， 鞘磷脂和胆碱在PE合成中的作用 单个磷脂的合成/周转率。实现第二个 目的：检测催乳素、胰岛素和佛波酯的结合情况； 主动转运；大分子合成；膜相关酶 在ETN存在或不存在的情况下，ETN反应细胞的活性。 这些研究将有助于理解膜的作用。 磷脂，特别是PE的磷脂，对各种细胞的调节 代谢过程、细胞增殖和分化。

The long term objective of our research is to understand the regulatory mechanisms of cell proliferation and differentiation of mammary epithelial cells. Mammalian cells in culture can be classified as ethanolamine (Etn)-responsive and -nonresponsive type with regard to the growth response. The Etn-responsive type includes normal rat mammary epithelial cells and some human and rat mammary carcinoma cells. Etn-responsiveness and prolactin-responsiveness of a mammary cell line seem to be coupled: some mammary cell lines are responsive to both agents and some others do not respond to either one of them. When Etn-responsive cells grow in Etn-deficient medium, phosphatidylethanolamine (PE) content in membrane phospholipid significantly reduces, suggesting that Etn-responsive cells can not synthesize or maintain adequate amounts of PE without the exogenous Etn, and that the PE-deficient membrane is not suitable for proper biological functions. Our immediate objective is 1) to elucidate the biochemical mechanism of Etn-responsiveness and 2) to examine the effect of PE-deficiency on prolactin action and other aspects of cellular metabolism. Etn-responsive and -nonresponsive rat mammary carcinoma cell lines will be used for the study. To achieve the first objective, various synthetic and turnover processes of PE will be examined. These include the examination of the activities of phosphatidylserine decarboxylase and enzymes that incorporate Etn into PE, the role of sphingomyelin and choline on PE synthesis, and the synthetic/turnover rate of individual phospholipids. To achieve the second objective, we will examine prolactin, insulin and phorbol ester bindings; active transport; macromolecular synthesis; and membrane associated enzyme activities of Etn-responsive cells grown in the presence or absence of Etn. These studies will contribute in understanding the role of the membrane phospholipids, particularly of PE, in regulation of various cellular metabolic processes, cell proliferation and differentiation.