Epithelial-mesenchymal transition in stem cell induction and maintenance

描述(由申请人提供)：了解诱导和维持癌症干细胞(CSCs)的机制对于开发能够有效靶向CSCs的治疗方法至关重要。越来越多的证据表明，CSCs和正常干细胞通常都有这样的机制。因此，对正常干细胞的研究对癌症干细胞生物学产生了重要的见解。上皮-间充质转化已被证明赋予分化的乳腺上皮细胞干细胞样属性(Mani等人。单元格2008)。然而，EMT是否在真正的乳腺干细胞诱导和维持中发挥作用尚不清楚。目前还没有严格的证据表明EMT可以诱导乳腺癌干细胞。此外，EMT激活干细胞程序的机制尚不清楚。为了研究EMT在干细胞诱导中的作用，我们将诱导原代乳腺上皮细胞(MECs)和癌细胞经历短暂的EMT，然后测试干细胞活性的增加。还将测试EMT将分化细胞转化为干细胞的能力。包括基因敲除和敲除在内的功能丧失方法将被用来测试在维持乳腺干细胞和乳腺癌干细胞中对EMT诱导因子的需求。干细胞相关信号通路在调节EMT激活干细胞程序中的作用也将在这项提案中进行研究。这些研究的积极结果将有助于更好地了解正常干细胞和癌症干细胞的生物学，并有助于开发癌症干细胞靶向治疗。此外，了解EMT和真性干细胞之间的联系将有助于产生用于研究和治疗的正常上皮干细胞。

DESCRIPTION (provided by applicant): Understanding the mechanisms involved in the induction and maintenance of cancer stem cells (CSCs) is critical for developing therapies that can target CSCs effectively. Increasing evidence has suggested such mechanisms are often shared by both CSCs and normal stem cells. Therefore, studies in normal stem cells yield important insights into the cancer stem cell biology. The epithelial-mesenchymal transition has been shown to confer differentiated mammary epithelial cells stem cell-like properties (Mani et al. Cell 2008). However, it is not clear whether the EMT plays a role in bona fide mammary stem cell induction and maintenance. It is also not yet rigorously demonstrated that the EMT can induce breast cancer stem cells. In addition, the mechanism by which the EMT activates stem-cell program is unknown. To examine the role of the EMT in the induction of stem cells, primary mammary epithelial cells (MECs) and cancer cells will be induced to undergo transient EMTs, and then tested for increases in stem cell activities. The ability of EMTs in converting differentiated cells into stem cells will also be tested. Loss-of-function approaches, including gene knock-out and knock-down, will be used to test the requirement of EMT- inducing factors in the maintenance of mammary stem cells and breast cancer stem cells. The involvement of stem cell-related signaling pathways in mediating the activation of the stem-cell program by the EMT will be also examined in this proposal. Positive outcomes ofthese studies will lead to better understanding ofthe biology of normal stem cells and cancer stem cells and help developing cancer stem cell-targeted therapies. In addition, understanding the link of EMT and bona fide stem cells will help generating normal epithelial stem cells for research and therapeutic uses.