MOLECULAR BIOLOGY OF STEROID HORMONE ACTION

类固醇激素通过特定的受体发挥作用，对 基因在几乎所有动物细胞中的表达。我们建议研究 糖皮质激素在明确组织培养中作用的分子生物学 从小鼠乳腺癌和大鼠肝癌细胞衍生的系统。这个 刺激小鼠乳腺肿瘤病毒(MMTV)RNA的产生 乳腺细胞和MMTV感染的大鼠肝癌中的糖皮质激素 细胞。使用各种分子技术(包括核酸 杂交和RNA测序)我们将通过以下方式研究生化过程 病毒的RNA合成受到刺激；尤其是，我们将尝试 确定启动病毒核糖核酸合成的启动子位置(S)。 病毒基因的转录将在分离的细胞核和染色质中进行研究 为了最终重建激素依赖的转录系统 体外培养。利用免疫学选择技术，大鼠的基因突变 肝癌细胞将在其中涉及一种或多种成分 在类固醇反应方面有缺陷。这些突变体将被用来识别 参与荷尔蒙作用的分子成分，并作为遗传 控制将生化观察与发生在 活着。这些方法不仅可以用来阐明分子机制 类固醇激素的作用，但也提供了一些进一步的见解 真核基因调控及其导致病毒诱导的事件 肿瘤发生学。

Steroid hormones function via specific receptors to exert dramatic effects on gene expression in virtually all animal cells. We propose to study the molecular biology of glucocorticoid action in well-defined tissue culture systems derived from mouse mammary carcinoma and rat hepatoma cells. The production of mouse mammary tumor virus (MMTV) RNA is stimulated by glucocorticoid hormones in the mammary cells and in MMTV-infected rat hepatoma cells. Using a variety of molecular techniques (including nucleic acid hybridization and RNA sequencing) we will study the biochemical processes by which viral RNA synthesis is stimulated; in particular, we will attempt to identify the promotor site(s) at which viral RNA synthesis is initiated. Transcription of viral genes will be studied in isolated nuclei and chromatin in order to eventually reconstruct hormone dependent transcription systems in vitro. Using immunological selection techniques, genetic mutants of the rat hepatoma cells will be developed in which one or more of the components involved in the steroid response is defective. These mutants would be used to identify the molecular components involved in hormone action and to serve as genetic controls in correlating biochemical observations with the events which occur in vivo. These approaches may serve not only to elucidate the molecular mechanisms of steroid hormone action but also to provide some further insights into eukaryotic gene regulation in general and the events leading to virally induced tumorigenesis.