ROLE OF POLYAMINES IN ESTROGEN FUNCTION IN BREAST CANCER

多胺在乳腺癌雌激素功能中的作用

• 批准号: 2090726
• 负责人: THRESIA THOMAS
• 金额: $ 20.84万
• 依托单位: UNIV OF MED/DENT NJ-R W JOHNSON MED SCH
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-04-15 至 1995-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2090726
• 关键词: MCF7 cell; acyltransferase; antineoplastics; breast neoplasms; cell cycle; circular dichroism; conformation; enzyme linked immunosorbent assay; estrogen receptors; estrogens; gel electrophoresis; hormone regulation /control mechanism; methionine adenosyltransferase; neoplastic growth; ornithine decarboxylase; plasmids; polyamines; spermidine; spermine; tamoxifen; tissue /cell culture

The overall goal of this proposal is to elucidate the mechanism of action of polyamines in estrogen-mediated growth of breast cancer cells. Polyamines are organic cations present in all cells. Estrogens play a key role in the origin and progression of breast cancer and an antiestrogen, tamoxifen, is the most effective form of therapy for a subset of human breast cancer. Mechanism of action of estrogen involves the interaction of the hormone to a specific intracellular protein, estrogen receptor (ER) followed by the recognition of ER to specific DNA sequences in the genome. Recognition of ER by these sequences, estrogen response elements (EREs), stimulates the transcription of responsive genes, DNA synthesis, and cell division. However, factors that modulate this interaction and the conformational alterations that are involved in transcriptional control of estrogenic function are not known. Previous studies from our laboratory and others have shown that polyamines play an essential role in estrogenic function. We hypothesize that polyamines are involved in the formation of high affinity complexes with ERE and thus modulate breast cancer cell growth. To test this hypothesis, we will quantity the effects of polyamines on ER-ERE interaction in terms of equilibrium binding constants and conformational alterations of ERE, using oligonucleotides and plasmids containing EREs. Polyamine structural specificity will be examined using homologs and derivatives of polyamines. The ability of polyamines and ER to provoke conformational alterations in ERE will be studied by circular dichroism spectroscopy, enzyme-linked immunosorbent assay, gel electrophoresis, and by chemical probes that detect single-stranded and left-handed (Z-DNA) regions in ERE. Polyamine analogs that do not support ER-ERE interactions will be studied in tissue culture experiments with an estrogen-responsive breast cancer cell line MCF-7. Possible additive/synergistic growth inhibitory effects of polyamine analogs will be studied in combination with tamoxifen. The uptake and mechanism of action of polyamine analogs will be further explored in terms of their ability to alter polyamine biosynthetic enzymes and inhibit cell cycle progression. An understanding of the mechanism of action of polyamines in ER-ERE recognition is critical to the understanding of transcriptional control of gene expression and cell growth in breast cancer. This information is important to the development of novel strategies for the treatment of breast cancer.

该提案的总体目标是阐明作用机制 多胺在雌激素介导的乳腺癌细胞生长中的作用。 多胺是存在于所有细胞中的有机阳离子。雌激素发挥关键作用 在乳腺癌的起源和进展中的作用和抗雌激素， 他莫昔芬，是对人类子集最有效的治疗形式 乳腺癌。 雌激素的作用机制涉及相互作用 激素与特定细胞内蛋白质（雌激素受体）的结合 (ER)，然后 ER 识别特定 DNA 序列 基因组。 通过这些序列、雌激素反应元件识别 ER (ERE)，刺激响应基因的转录、DNA 合成， 和细胞分裂。 然而，调节这种相互作用的因素和 转录过程中涉及的构象改变 雌激素功能的控制尚不清楚。 我们实验室和其他实验室之前的研究表明 多胺在雌激素功能中发挥重要作用。 我们假设 多胺参与高亲和力复合物的形成 与 ERE 结合，从而调节乳腺癌细胞的生长。 为了测试这个 假设，我们将量化多胺对 ER-ERE 的影响 平衡结合常数和构象方面的相互作用 使用含有 ERE 的寡核苷酸和质粒来改变 ERE。 将使用同系物和 多胺的衍生物。 多胺和 ER 引发 ER 的能力 ERE 中的构象变化将通过圆二色性进行研究 光谱学、酶联免疫吸附测定、凝胶电泳等 通过检测单链和左手 (Z-DNA) 的化学探针 ERE 中的区域。 不支持 ER-ERE 的多胺类似物 将在组织培养实验中研究相互作用 雌激素反应性乳腺癌细胞系MCF-7。 可能的 多胺类似物的加和/协同生长抑制作用将 与他莫昔芬联合研究。 吸收和机制 多胺类似物的作用将进一步探讨其作用 改变多胺生物合成酶和抑制细胞周期的能力 进展。 了解多胺在 ER-ERE 中的作用机制 识别对于理解转录控制至关重要 乳腺癌中基因表达和细胞生长的研究。 该信息是 对于制定新的治疗策略非常重要 乳腺癌。