Regulatory Mechanisms Controlling Breast Tissue Development and Transformation

我们试图了解控制乳腺组织发育的分子调控机制， 乳腺上皮细胞转化SWI/SNF染色质重塑酶控制细胞的可及性， 基因组染色质，并在启动多重分化程序， 调节细胞周期进程和基因表达。这些酶与肿瘤抑制剂相互作用， 而单个亚单位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发现，SWI/SNF ATP酶亚基之一的敲低导致了 在改变的核形状中，确定SWI/SNF酶是少数已知的核调节蛋白之一， 在核结构中起作用。Runx 2转录调节因子在哺乳动物中以升高的水平表达， 一些乳腺癌细胞和其他癌细胞。我们和其他P01研究人员证明，RUNX 2的功能是 一种致癌基因，通过促进乳腺上皮细胞转化的早期阶段， 取决于正确的亚核定位。我们建议从机制上解决SWI/SNF如何 酶和RUNX 2促进导致癌症的核和细胞结构的变化。以来 发展和恶性转化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，其重现组织的微环境， 允许细胞外基质和核基因表达之间的动态和相互串扰。在 在本申请中，我们将研究SWI/SNF酶在永生化， 单层和三维转化和转移的乳腺上皮细胞，重建 基底膜培养（Aim 1）。我们将进一步探讨这些酶在维持细胞核中的作用。 通过探索因子的损失如何影响核结构的各种参数（目的2）来确定形状。在目标3中， 我们将继续研究RUNX 2在乳腺上皮细胞肿瘤发生中的功能，并将探索如何 SWI/SNF和RUNX 2因子可能协同促进细胞转化。 相关性（参见说明）： 许多癌症的标志是细胞核形态和功能状态的改变。我们有 显示已知影响核结构参数的关键调节因子调节细胞 与乳腺上皮细胞分化相关的性质。我们试图了解分子 这些观察的基础。

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.