Characterization of estrogen and progesterone receptors and the dissociated regulation of growth and progesterone receptor stimulation by estrogen in MDA-MB-134 human breast cancer cells.
Characterization of estrogen and progesterone receptors and the dissociated regulation of growth and progesterone receptor stimulation by estrogen in MDA-MB-134 human breast cancer cells.
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发表时间：
1986-03
期刊：
影响因子：
11.2
通讯作者：
Georg C. A. Reiner;B. Katzenellenbogen
中科院分区：
文献类型：
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作者：
Georg C. A. Reiner;B. Katzenellenbogen
我们研究了MDA-MB-134人乳腺细胞中雌激素受体和孕激素受体的特性，并评估了雌激素对这些细胞中细胞增殖和孕激素受体水平的影响，作为激素敏感性的指标。这些细胞含有高水平的雌激素受体（约1.5 pmol/mg DNA）和低水平的孕酮受体（0.15 pmol/mg DNA）。在没有雌激素的情况下，超过80%的雌激素受体存在于细胞核部分，雌二醇受体的Kd约为1.5 × 10 - 10 M。暴露于雌二醇后，受体被占据，但细胞核或总细胞雌激素受体含量没有加工或明显减少，如在MCF-7人乳腺癌细胞中所见。核雌激素受体在高盐蔗糖梯度上以4.6 S物质沉淀，并且可以在十二烷基硫酸钠-聚丙烯酰胺凝胶免疫印迹分析上检测到其为分子量65，000的物质，与MCF-7雌激素受体的分子量相同，使用针对MCF-7雌激素受体制备的单克隆抗体D 75 P3 γ和H222 Sp γ。雌激素受体显示出对雌激素和抗雌激素的结合选择性，并且其对配体的亲和力遵循己烯雌酚（190%）大于雌二醇（100%）大于雌三醇（13%）大于他莫昔芬（3%）的顺序，如对雌激素受体的预期。因此，该受体在其许多理化性质以及其对雌激素和抗雌激素的结合亲和力和特异性方面表现正常。对照细胞含有低水平的孕激素受体，对合成孕激素R5020表现出高亲和力（Kd = 6 X 10（-9）M），但暴露于雌二醇（10（-11）-10（-7）M）未能增加细胞孕激素受体水平。相反，雌二醇显著刺激细胞增殖的速率，而他莫昔芬抑制对照和雌二醇处理的细胞的生长。因此，我们的数据表明，这些细胞，其中含有大量的雌激素受体水平，响应雌激素与增强的细胞增殖，但不能有他们的孕酮受体水平调节雌二醇。这些细胞代表了一个有趣的和不寻常的情况下，雌激素调节增殖和孕酮受体的刺激是分离的。这些细胞应证明在进一步评估雌激素调节细胞增殖和特定的蛋白质合成在人类乳腺癌中是有用的。
We have examined the properties of the estrogen receptor and progesterone receptor in MDA-MB-134 human breast cells and have evaluated the effects of estrogen on cell proliferation and progesterone receptor levels in these cells as indices of hormonal sensitivity. These cells contain high levels of estrogen receptor (approximately 1.5 pmol/mg DNA) and low levels of progesterone receptor (0.15 pmol/mg DNA). More than 80% of the estrogen receptor is found in the nuclear fraction in the absence of estrogen, and the Kd of the receptor for estradiol is approximately 1.5 X 10(-10) M. Upon exposure to estradiol, the receptors become occupied, but there is no processing or apparent decrease in either nuclear or total cellular estrogen receptor content, as can be seen in MCF-7 human breast cancer cells. The nuclear estrogen receptor sediments as a 4.6 S species on high salt sucrose gradients, and it can be detected on sodium dodecyl sulfate-polyacrylamide gel immunoblot analysis as a species of molecular weight 65,000, identical to that of the MCF-7 estrogen receptor, using the monoclonal antibodies D75P3 gamma and H222Sp gamma prepared against the MCF-7 estrogen receptor. The estrogen receptor shows binding selectivity for estrogens and antiestrogens, and its affinity for ligands follows the order diethylstilbestrol (190%) greater than estradiol (100%) greater than estriol (13%) greater than tamoxifen (3%), as expected for estrogen receptor. Hence the receptor appears normal in many of its physicochemical properties and in terms of its binding affinity and specificity for estrogens and antiestrogens. Control cells contain low levels of progesterone receptor that display high affinity (Kd = 6 X 10(-9) M) for the synthetic progestin R5020, but exposure to estradiol (10(-11)-10(-7)M) fails to increase cellular progesterone receptor levels. In contrast, estradiol markedly stimulates the rate of cell proliferation, while tamoxifen suppresses the growth of control and of estradiol treated cells. Hence, our data show that these cells, which contain substantial levels of estrogen receptor, respond to estrogen with enhanced cell proliferation but fail to have their progesterone receptor level modulated by estradiol. These cells represent an interesting and unusual situation in which estrogenic regulation of proliferation and the stimulation of progesterone receptor are dissociated. These cells should prove useful in further evaluation of estrogenic regulation of cell proliferation and specific protein synthesis in human breast cancer.