Mammary basal/stem cell plasticity and regulation

项目摘要 将无数分化的细胞重新编程回到多能干细胞状态的能力突出了 体细胞具有显著的可塑性需要努力更好地了解组织的内在可塑性 干细胞以及潜在的调节机制，这样我们就可以了解如何控制细胞 组织工程和再生医学的未来长期以来，人们都知道上皮细胞具有固有的 可塑性，最好的表现是它们能够成为间充质细胞，以及恢复到一个 在适当的刺激下，上皮状态。这种可塑性对于生成间充质细胞类型很重要 在胚胎发生期间，并且被认为是恶性癌细胞形成远处转移所必需的。 最近的研究激发了一种假设，即调节这种可塑性的机制被用于 定向组织上皮细胞来控制干细胞的命运。乳腺上皮细胞是一个很好的模型 系统来测试这一假设，由于既定的方法，前瞻性地隔离和功能 表征其驻留干细胞。乳腺上皮基底层有多能干 细胞和在移植和妊娠等条件下可以转化为干细胞的细胞。我们 将有机地联合收割机尖端的单细胞分析与国家或最先进的技术，如组织特异性 基因敲除和诱导性过表达、体内和离体干细胞测定以及分子研究 为了解决以下基本重要的问题：1）有多少细胞类型子集或细胞状态 存在于乳腺基底细胞群中，这些状态是否对应于光谱中的不同位置 上皮细胞/EMT可塑性2)是多能干细胞还是有能力成为这种干细胞的细胞 部分由其高可塑性定义，即采用间充质样和终末 上皮细胞的命运3)调节这种可塑性的关键分子回路是什么，以及这种分子回路是否/如何调节这种可塑性。 电路决定了基底细胞处于干细胞状态？

PROJECT SUMMARY The ability to reprogram myriad differentiated cells back into a pluripotent stem cell state highlights the remarkable plasticity of somatic cells. Effort is needed to better understand the inherent plasticity of tissue stem cells as well as the underlying regulatory mechanisms, so that we can learn about how to control cell fates in tissue engineering and regenerative medicine. Epithelial cells are long known to possess inherent plasticity, best manifested by their ability to become mesenchymal cells as well as to revert back to an epithelial state, under appropriate stimuli. This plasticity is important for generating mesenchymal cell types during embryogenesis, and is thought to be required for malignant cancer cells to form distant metastases. Recent studies have inspired the hypothesis that the mechanisms that regulate this plasticity are used in committed tissue epithelial cells to control stem cell fates. The mammary epithelia serve an outstanding model system to test this hypothesis, owing to the well-established methods to prospectively isolate and functionally characterize their residential stem cells. The basal layer of the mammary epithelia harbors multipotent stem cells and cells that can turn into such stem cells under conditions such as transplantation and pregnancy. We will organically combine cutting-edge single-cell analysis with state-or-art technology such as tissue-specific gene knockout and inducible overexpression, in vivo and ex vivo stem cell assays, as well as molecular studies to address the following fundamentally important questions: 1) How many cell type subsets or cellular states exist in the mammary basal cell population and do these states correspond to distinct positions in the spectrum of epithelial/EMT plasticity? 2) Are multipotent stem cells or cells with the capacity to become such stem cells defined in part by their high plasticity, namely the potential to adopt both mesenchymal-like and terminal epithelial fates? 3) What is the key molecular circuitry that regulates such plasticity, and whether/how this circuitry dictates the stay of a basal cell in a stem cell state?