ALKYL PCDFS--INHIBITION OF MAMMARY CANCER

烷基PCDFS--抑制乳腺癌

• 批准号: 2390836
• 负责人: Stephen H. Safe
• 金额: $ 15.95万
• 依托单位: TEXAS A&M UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-04-14 至 1999-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2390836
• 关键词: MCF7 cell; analog; antineoplastics; aromatic hydrocarbon receptor; athymic mouse; benzanthracenes; bioassay; breast neoplasms; chemical related neoplasm /cancer; drug interactions; epidermal growth factor; estrogen inhibitor; estrogen receptors; flow cytometry; hormone related neoplasm /cancer; human genetic material tag; insulin; insulinlike growth factor; laboratory rat; neoplasm /cancer pharmacology; neoplastic cell; polychlorodibenzofuran; polymerase chain reaction; southern blotting; tamoxifen; transforming growth factors

Previous studies have demonstrated that 2,3,7,8-tetrachlorodibenzo-p- dioxin (TCDD) inhibits a broad spectrum of estrogen-induced responses in the female rat uterus and in MCF-7 human breast cancer cells. TCDD also inhibits mammary tumor formation in rats and in mice transplanted with MCF-7 cells. 6-Methyl-1,3,8-trichlorodibenzofuran (MCDF) and related alkyl polychlorodibenzofurans (PCDFs) are relatively non-toxic analogs of TCDD which exhibit comparable in vitro and in vivo antiestrogenic and antitumorigenic activities. Thus, the alkyl PCDFs represent a new class of antiestrogens which act through the aryl hydrocarbon (Ah) receptor signal transduction pathway and thus may have clinical potential as chemotherapeutic agents for treatment of breast cancer. TCDD and MCDF, are potent antiestrogens in T47D and MCF-7 human breast cancer cells (ER- and AhR-positive, ER+AhR+) but exhibit minimal activity in ER-AhR- MDA-MB-231 cells. The in vitro or in vivo effects of alkyl PCDFs or TCDD on ER-AhR+ or ER+AhR- cells have not been previously investigated due to the unavailability of these cell lines. Experiment 1 of this project will thoroughly characterize a series of ER-AhR+ and ER+AhR- variant breast cancer cell lines. ER+AhR- cells will be isolated by culturing MCF-7 and T47D cells in 1 micromole benzo[a]pyrene (BaP) and the ER+AhR- variant cell lines will be fully characterized. ER-AhR+ variant cells will be isolated from high passage T47D cells and from MDA-MB-231 cells (ER-AhR-) stably transfected with the human arnt gene which restores Ah- responsiveness in this cell line. The resultant stable transfectants will represent an ER-AhR+ phenotype which hitherto has not been described. Moreover, since MDA-MB-231 cells are resistant to endocrine and cytotoxic drug therapy, the ER-AhR+ cells will serve as a model for assessing the antitumorigenic and antiproliferative effects of AhR agonists (e.g. alkyl PCDFs) in these cells. Although the growth of MDA-MB-231 cells are estrogen-independent, various growth factors (IGF-l, EGF, TGFalpha, insulin) act as mitogens and, therefore, growth factor-induced proliferation and a number of other characteristics of the ER-AhR+ stable transfectant cell lines will be thoroughly.investigated. Immune deficient mice transplanted with breast cancer cells will be utilized in Experiment 2 to (a) determine the factors which control the development of tumors in athymic mice transplanted with the wild-type and variant breast cancer cell lines characterized in Experiment 1 and (b) assess the relative potencies of TCDD and the alkyl PCDFs as chemotherapeutic agents in this in vivo model. In parallel studies, the relative potencies of the alkyl PCDF as antiestrogens will also be determined in the female rat uterus. These short-term studies will provide critical relative potency data for this series of alkyl PCDFs in a well-established estrogen-responsive target organ and prioritize their use in in vivo studies (Experiment 4) on the antitumorigenicity of selected congeners in the DMBA-induced rat tumor model. These proposed studies will provide critical new data on the mechanism of action of AhR agonists as antiestrogens and antitumorigenic agents in two in vivo models and determine which alkyl PCDFs should be further investigated as potential chemotherapeutic agents for treatment of mammary cancer.

先前的研究表明，2,3,7,8-四氯二苯并-p- 二恶英 (TCDD) 广泛抑制雌激素诱导的反应 雌性大鼠子宫和 MCF-7 人乳腺癌细胞中。 TCDD 还 抑制大鼠和移植小鼠乳腺肿瘤的形成 MCF-7 细胞。 6-甲基-1,3,8-三氯二苯并呋喃 (MCDF) 及相关产品 烷基多​​氯二苯并呋喃 (PCDF) 是相对无毒的类似物 TCDD 在体外和体内表现出可比的抗雌激素和 抗肿瘤活性。因此，烷基 PCDF 代表了一类新的 通过芳烃 (Ah) 受体信号发挥作用的抗雌激素 转导途径，因此可能具有临床潜力 用于治疗乳腺癌的化疗剂。 TCDD 和 MCDF 是 T47D 和 MCF-7 人乳腺癌细胞（ER-和 AhR 阳性，ER+AhR+），但在 ER-AhR-MDA-MB-231 中表现出最小的活性 细胞。烷基 PCDF 或 TCDD 对 ER-AhR+ 的体外或体内影响 或 ER+AhR- 细胞之前尚未进行过研究，因为 这些细胞系的不可用性。本项目的实验1将 彻底表征一系列 ER-AhR+ 和 ER+AhR- 变异乳房 癌细胞系。 ER+AhR-细胞将通过培养MCF-7和 1 微摩尔苯并[a]芘 (BaP) 和 ER+AhR- 变体中的 T47D 细胞 细胞系将得到充分表征。 ER-AhR+ 变异细胞将 从高传代 T47D 细胞和 MDA-MB-231 细胞 (ER-AhR-) 中分离 稳定转染人类 arnt 基因，恢复 Ah- 该细胞系的反应性。所得的稳定转染子将 代表迄今为止尚未描述的ER-AhR+表型。 此外，由于 MDA-MB-231 细胞对内分泌和细胞毒性具有抵抗力 药物治疗后，ER-AhR+细胞将作为评估药物治疗效果的模型 AhR 激动剂（例如烷基 PCDF）在这些细胞中。尽管 MDA-MB-231 细胞的生长 不依赖雌激素的多种生长因子（IGF-1、EGF、TGFα、 胰岛素）作为有丝分裂原，因此，生长因子诱导 ER-AhR+ 稳定的增殖和许多其他特征 转染细胞系将被彻底研究。免疫缺陷 移植乳腺癌细胞的小鼠将用于实验 2至(a)确定控制肿瘤发展的因素 移植了野生型和变异型乳腺癌的无胸腺小鼠 实验 1 和 (b) 中表征的细胞系评估相对 TCDD 和烷基 PCDF 作为化疗药物的效力 体内模型。在平行研究中，烷基的相对效力 作为抗雌激素的 PCDF 也将在雌性大鼠子宫中进行测定。 这些短期研究将为以下方面提供关键的相对效力数据： 该系列烷基 PCDF 具有完善的雌激素反应性 目标器官并优先考虑其在体内研究（实验 4）中的使用 选定同系物在 DMBA 诱导的大鼠肿瘤中的抗肿瘤作用 模型。这些拟议的研究将提供关于 AhR 激动剂抗雌激素和抗肿瘤作用的作用机制 剂在两个体内模型中并确定哪些烷基 PCDF 应该是 进一步研究作为潜在的化疗药物治疗 乳腺癌。