Comparative studies of aromatase inhibitors in cultured human breast cancer cells.
Comparative studies of aromatase inhibitors in cultured human breast cancer cells.
复制标题
芳香酶抑制剂在培养的人乳腺癌细胞中的比较研究。
作者：
J. MacIndoe;G. Woods;L. A. Etre;D. Covey
MCF-7人乳腺癌细胞中芳香化酶活性、雌激素受体和雌激素反应性的存在使得该细胞系被用作研究潜在治疗芳香化酶抑制剂生物活性的独特体外系统。我们现在报告了在MCF-7单层培养物中检测氨酰硫胺、1,2-脱氢睾内酯（睾内酯）、二氢睾酮、4-羟基-4-雄烯-3,17-二酮和10-异丙酯-4-烯-3,17-二酮的细胞毒性、抗芳香酶和内在雌激素活性的研究结果。通过台盼蓝排除法测定细胞活力，通过定量测定由[3H]睾酮生成的[3H]雌二醇的量来评估芳香酶活性。在5天的潜伏期内，通过检测每种抑制剂增加细胞质孕酮受体和消耗细胞质雌激素受体浓度的能力来评估雌激素活性。细胞质孕酮和雌激素受体分别以[17 α -甲基-3H]-17 α， 21-二甲基-19-去甲孕酮-4,9-二烯-3,20-二酮和[3H]雌二醇为标记配体，采用单饱和剂量技术进行测定。结果表明，这些化合物在MCF-7细胞中都是无细胞毒性的芳香酶抑制剂，但它们的抑制效力有显著差异（10-丙炔-4-烯-3,17-二酮大于4-羟基-4-雄烯-3,17-二酮，大于二氢睾酮，大于睾酮内酯=氨酰硫胺）。与4-羟基-4-雄烯-3,17-二酮孵育的细胞导致细胞质孕酮和雌激素受体的反应，其程度与在其他培养物中观察到的与等摩尔浓度的雌二醇孵育的反应相似。其他四种药物在该系统中均未显示出雌激素活性。然而，我们之前已经观察到双氢睾酮在该系统中具有实质性的抗雌激素作用。综上所述，这些结果表明，一些芳香酶抑制剂可能通过不止一种机制影响人类乳腺癌细胞的激素调节。
The presence of aromatase activity, estrogen receptors, and estrogenic responsiveness in MCF-7 human breast cancer cells has allowed this cell line to be used as a unique in vitro system for investigating the biological activities of potentially therapeutic aromatase inhibitors. We now report the results of studies which have examined the cytotoxicity, antiaromatase, and intrinsic estrogenic activities of aminoglutethimide, 1,2-dehydrotestolactone (testolactone), dihydrotestosterone, 4-hydroxy-4-androstene-3,17-dione, and 10-propargylestr-4-ene-3,17-dione within MCF-7 monolayer cultures. Cell viability was determined by trypan blue exclusion, and aromatase activity was assessed by quantifying the amounts of [3H]estradiol formed from [3H]testosterone. Estrogenic activity was assessed by examining the ability of each inhibitor to increase cytoplasmic progesterone receptor and deplete cytoplasmic estrogen receptor concentrations in these cells during a 5-day incubation period. Cytoplasmic progesterone and estrogen receptors were measured by the single-saturating-dose technique using [17 alpha-methyl-3H]-17 alpha, 21-dimethyl-19-norpregna-4,9-diene-3,20-dione and [3H]estradiol as the labeled ligands for each assay, respectively. The results showed that all of these compounds were noncytotoxic aromatase inhibitors in MCF-7 cells but that these agents demonstrated marked differences in inhibitory potency (10-propargylestr-4-ene-3,17-dione greater than 4-hydroxy-4-androstene-3,17-dione much greater than dihydrotestosterone much greater than testolactone = aminoglutethimide). The incubation of cells with 4-hydroxy-4-androstene-3,17-dione resulted in cytoplasmic progesterone and estrogen receptor responses that were similar in magnitude to those observed in other cultures incubated with equimolar concentrations of estradiol. None of the other four agents demonstrated estrogenic activity in this system. However, we have previously observed that dihydrotestosterone has substantial antiestrogenic action in this system. Taken together, these results indicate that some aromatase inhibitors may influence the hormonal regulation of human breast cancer cells by more than one mechanism.