Regulatory Mechanisms Controlling Breast Tissue Development and Transformation

我们试图了解控制乳房组织发育的分子调控机制 乳腺上皮细胞转化。SWI/SNF染色质重塑酶控制可及性 基因组染色质，在启动多个分化程序中至关重要，通过 调节细胞周期进程和基因表达。这些酶与肿瘤抑制因子相互作用， 而个别亚基本身就是肿瘤抑制因子。我们的研究表明，SWI/SNF酶可以 调节基因表达、核和细胞形态、增殖和组织发育 乳腺上皮细胞。我们还显示了SWI/SNFATPase亚基之一的敲除结果 在改变的核形状中，确定SWI/SNF酶是为数不多的已知的中性调节蛋白之一 这在核结构中起到了作用。Runx2转录调节因子在 一些乳腺和其他癌细胞。我们和其他P01研究人员证明了RUNX2的功能 一种通过完全促进乳腺上皮细胞转化的早期阶段的癌基因 依赖于适当的亚核定位。我们建议机械地解决SWI/SNF如何 酶和RUNX2促进导致癌症的核和细胞结构的变化。自.以来 发展和恶变发生在一个三维的背景下，我们正在利用模型 正常和转化的乳腺细胞系统，概括了组织的微环境和 允许细胞外基质和核基因表达之间的动态和相互串扰。在……里面 在这一应用中，我们将研究SWI/SNF酶在永生化、 单层和三维重组转化和转移的乳腺上皮细胞 基底膜培养(目标1)。我们将进一步探讨这些酶在维持核功能中的作用 通过探索这些因素的损失如何影响核结构的各种参数来塑造(目标2)。在《目标3》中， 我们将继续研究RUNX2在乳腺上皮细胞肿瘤发生中的作用，并将探索如何 SWI/SNF和RUNX2因子可能协同促进细胞转化。 相关性(请参阅说明)： 许多癌症的一个特点是细胞核的形态和功能状态发生了变化。我们有 已知影响核结构参数的关键调控因素调节细胞 与乳腺上皮细胞转化相关的特性。我们试图理解分子 为这些观察提供了依据。

We seek to understand molecular regulatory mechanisms controlling breast tissue development and mammary epithelial cell transformation. SWI/SNF chromatin remodeling enzymes control the accessibility of genomic chromatin and are vitally important in the initiation of multiple differentiation programmes through regulation of cell cycle progression and gene expression. These enzymes interact with tumor suppressors, and individual subunits are tumor suppressors themselves. Our studies indicate that SWI/SNF enzymes can modulate gene expression, nuclear and cellular morphology, proliferation, and tissue development in mammary epithelial cells. We also showed that knockdown of one ofthe SWI/SNF ATPase subunits results in altered nuclear shape, identifying SWI/SNF enzymes as one of the few known nudear regulatory proteins that has a role in nuclear structure. The Runx2 transcriptional regulator is expressed at elevated levels in some breast and other cancer cells. We and other P01 investigators demonstrated that RUNX2 functions as an oncogene by promoting early stages of mammary epithelial cell transformation in a manner entirely dependent on proper subnuclear localization. We propose to mechanistically address how SWI/SNF enzymes and RUNX2 promote changes in nuclear and cellular architecture that lead to cancer. Since development and malignant transformation take place in a three dimensional context, we are utilizing model systems of normal and transformed breast cells that recapitulate the microenvironment of a tissue and that permit the dynamic and reciprocal crosstalk between the extracellular matrix and nuclear gene expression. In this application, wewill investigate the physiological functions for SWI/SNF enzymes in immortalized, transformed, and metastatic mammary epithelial cells in monolayer and in three dimensional, reconstituted basement membrane culture (Aim 1). We will further probe the role ofthese enzymes in maintaining nuclear shape by exploring how loss of the factors affects various parameters of nuclear structure (Aim 2). In Aim 3, we will continue studies of RUNX2 function in mammary epithelial cell oncogenesis and will explore how SWI/SNF and RUNX2 factors may cooperate to promote cell transformation. RELEVANCE (See instructions): A hallmark of many cancers is the altered morphological and functional state ofthe cell nucleus. We have shown that key regulatory factors known to affect parameters of nuclear structure modulate cellular properties associated with mammary epithelial cell transfomation. We seek to understand the molecular basis for these observations.