Exploiting the epithelial-to-mesenchymal transition for the differentiation of cancer stem cells

项目摘要 大约15%-20%的乳腺癌患者属于基底样型，代表着不同的亚型。 这是以更具侵袭性的肿瘤为特征的，预后较差。死于这些疾病 癌症是由于疾病向远处的转移扩散和治疗耐药造成的， 导致癌症复发，形成难以控制的更具侵袭性的形式。这两个属性 归因于它们通过包括克隆进化在内的各种机制产生的细胞异质性 以及癌症干细胞(CSCs)的存在。上皮向间充质转化(EMT)是一种程序 我们已经证明对具有CSC样属性的细胞的产生负责。 我们目前的建议旨在通过诱导间充质干细胞向- 上皮转化(MET)。为了做到这一点，我们进行了一项筛选，以识别能够 诱导上皮/非CSC状态的标志E-钙粘蛋白的转录 间充质/CSC样细胞。通过这个筛选，我们确定了cAMP激活剂forsklin能够诱导 E-钙粘素转录和间充质/CSCs向更良性的上皮状态逆转。穿过 这项提案旨在揭示cAMP提高剂能够诱导MET的机制 通过完整地描述信号的重要下游成分，即蛋白激酶A (PKA)及其下游底物。我们的目标也是理解发生的表观遗传重新编程 在组蛋白修饰酶PHF2的作用下激活PKA。这两者都是 组件将解决将CSC区分为呈现它们的状态的机制 对阿霉素等化疗药物治疗高度敏感。 尽管经过了二十多年的研究，我们仍然缺乏针对CSCs的能力。通过研究 关于调节cAMP水平的磷酸二酯酶和G蛋白偶联受体(GPCRs)，我的目标是 开发专门诱导CSCs分化的方法，这些方法可以翻译成治疗用途。

Project Summary About 15-20% of breast cancer patients fall under the basal-like category, which represent a diverse subtype that is characterized by tumors that are more aggressive conferring poor prognosis. Deaths from these carcinomas result from metastatic spread of the disease to distant sites and from therapeutic resistance, which results in the relapse of cancers into more aggressive forms that are difficult to contain. Both these properties are attributed to their cellular heterogeneity that arises through various mechanisms including clonal evolution and the presence of cancer stem cells (CSCs). The epithelial-to-mesenchymal transition (EMT) is one program that we have shown to be responsible for the generation of cells that have CSC-like properties. Our current proposal aims to induce differentiation of these CSCs through the induction of a mesenchymal-to- epithelial transition (MET). To do this, we carried out a screen to identify compounds that are capable of inducing the transcription of E-cadherin, a hallmark of the epithelial/non-CSC state, in cells that are more mesenchymal/CSC-like. Through this screen we identified Forskolin, an activator of cAMP, to be able to induce E-cadherin transcription and a reversion of the mesenchymal/CSCs to a more benign epithelial state. Through this proposal we aim to uncover the mechanism by which cAMP-elevating agents are able to induce an MET by complete characterization of the essential downstream components of signalling, namely Protein Kinase A (PKA) and its downstream substrates. We also aim to understand the epigenetic reprogramming that occurs following activation of PKA through the functions of the histone-modifying enzyme PHF2. Both these components will address the mechanisms by which CSCs can be differentiated to a state that renders them highly sensitive to treatment with chemotherapeutic agents such as doxorubicin. Despite over two decades of research, our ability to specifically target CSCs is still lacking. Through the study of Phosphodiesterases and G-Protein Coupled Receptors (GPCRs) that modulate cAMP levels, I aim to develop ways to specifically induce differentiation of CSCs that can be translated for therapeutic utility.