MECHANISM OF HORMONE ACTION ON TARGET CELLS IN CULTURE

这项建议的长远目标是以机械方式界定 调节正常和肿瘤组织中的细胞增殖。 人血清 抑制雌激素敏感的人乳腺癌细胞的增殖; 雌激素以特定的方式克服这种作用。 其他性类固醇 并且生长因子在逆转这种抑制方面完全无效。 抑制作用似乎是由于热稳定，蛋白酶敏感， 表观分子量= 70-90 kDa的分子和等电点 打印4.5-4.8。 本申请的具体目的是进一步 使用多种方法纯化这种特异性抑制剂，包括： 疏水作用和螯合色谱法，制备型 等电聚焦，凝胶过滤，二维聚丙烯酰胺凝胶 电泳、HPLC/FPLC和单克隆和多克隆抗体。 的 生物测定以测量纯化级分的抑制性质 利用MCF 7人类乳腺肿瘤细胞。 这些生理抑制剂的潜在临床意义 乳腺癌细胞的增殖是多方面的。 这些措施包括： 更准确地说明乳腺肿瘤对治疗药物的反应， 在读取组织病理学样本时做出的决定; 血浆抑制剂被认为是一种更可靠的标记物， 预后比现在使用的探针（雌激素受体等）。 同样 重要的是，我们正在纯化的抑制剂的可用性，将允许 现在提出的假设测试，以解释控制 雌激素敏感细胞增殖。

The long term objective of this proposal is to define mechanistically the regulation of cell proliferation in normal and tumor tissues. Human serum inhibits the proliferation of estrogen-sensitive human breast cancer cells; estrogens overcome this effect in a specific manner. Other sex steroids and growth factors are completely ineffective in reversing this inhibition. The inhibitory effect seems to be due to a heat-stable, protease-sensitive molecule of an apparent molecular weight = 70-90 kDa and an isoelectric print of 4.5-4.8. The specific aim of this application is to further purify this specific inhibitor using a variety of procedures including: hydrophobic interaction and chelating chromatography, preparative isoelectric focusing, gel filtration, 2 dimensional polyacrylamide gel electrophoresis, HPLC/FPLC and mono and polyclonal antibodies. The bioassay to measure the inhibitory properties of the purified fractions makes use of MCF7 human breast tumor cells. The potential clinical relevance of these physiologic inhibitors of the proliferation of breast cancer cells are manifold. They include ways to more accurately prognosticate the response of breast tumors to therapeutic decisions taken when histopathological samples are read; receptors for the plasma-borne inhibitors are anticipated to be a more reliable marker of prognosis than probes used now (estrogen receptor, etc.). Equally important, availability of the inhibitory we are purifying, will allow for testing of hypotheses now being proposed to explain the control of estrogen-sensitive cell proliferation.