Research Project 2: Targetin Tumor-Initiating Cell (TIC) Heterogeneity To Overcome Chemotherapy Resistance

项目摘要 我们和其他人已经表明，一个能够再生新肿瘤的肿瘤细胞亚群， 作为肿瘤起始细胞（TIC）或“癌症干细胞”（CSC），对目前的系统性免疫应答具有相对抗性。 化疗和放疗相对于肿瘤的体积。因此，我们在这方面工作的指导前提是， 在过去的十年中，治疗靶向TIC生存或功能所需的过程将允许 在原发部位和转移部位消除这些细胞，从而增强对电流的响应 全身治疗。然而，从几个实验室使用目前的细胞表面标记物， Wnt、Hedgehog和STAT 3介导的酶活性标记物和慢病毒信号转导报告基因 信号，TIC不仅在肿瘤之间是异质的，而且还表现出不同的行为，治疗 反应，以及在给定肿瘤模型内的原发和转移位点的报告基因表达。因此，在本发明中， 了解肿瘤内和肿瘤间TIC类型的多样性， 这些细胞在原发部位和转移部位之间的功能如何不同，以便有效地靶向它们- 特别是在“三阴性”乳腺癌（TNBC）中，对于其没有批准的靶向疗法。 我们假设TNBC中存在分子上不同类别的TIC。因此，差分 对个体化疗的反应部分取决于给定肿瘤中存在的TIC的种类。如果 真的，我们进一步断言，识别和定位类特定的TIC功能可能有助于克服 化疗耐药性 为了鉴定在PDX衍生的TIC谱中起作用的候选调控基因或途径， 从原发和转移部位分离，我们建议首先确定TIC是否来源于 原发或转移部位显示出相同或不同的信号网络激活模式， 使用对信号传导途径和转录因子特异的慢病毒荧光报告物的TIC功能 与TIC功能有关。然后，我们将确定候选的TIC活动所需的分子机制， 使用RNAseq的群体和单细胞水平。 为了确定体内靶向TIC相关基因/途径是否可以增强对TlC的应答， 卡铂，并导致消除不同类别的TIC在原发和转移部位，我们将 评价FDA批准的靶向TIC的药物单独或联合治疗增强治疗应答的能力 在原发和转移部位联合卡铂，并测定治疗对TIC的影响 在体内发挥作用。结果可用于指导人体临床试验的规划和执行，并为 精准医疗的努力

PROJECT SUMMARY We and others have shown that a subset of tumor cells capable of regenerating new tumors, termed variously as tumor-initiating cells (TIC) or “cancer stem cells” (CSC), are comparatively resistant to current systemic chemo- and radio-therapies relative to the bulk of the tumor. As such, the guiding premise for our work over the past decade, is that therapeutic targeting of processes required for survival or function of TIC will allow elimination of such cells at both the primary and metastatic sites, thereby enhancing response to current systemic therapies. However, it has become clear from several laboratories using current cell surface markers, enzymatic activity markers, and lentiviral signaling reporters for Wnt, Hedgehog, and STAT3-mediated signaling, that TIC are heterogeneous not only across tumors, but also show different behaviors, treatment responses, and reporter gene expression at the primary and metastatic sites within a given tumor model. Thus, it is critical to understand the diversity of TIC types both within and across tumors, as well as to understand how such cells differ in function between the primary and metastatic site, in order to target them effectively – particularly in “triple-negative” breast cancer (TNBC), for which there are no approved targeted therapies. We hypothesize that there exist molecularly distinct classes of TIC in TNBC. As a consequence, differential responses to individual chemotherapies depend, in part, on the class(es) of TIC present in a given tumor. If true, we further assert that identifying and targeting class-specific TIC functions may help overcome chemotherapy resistance. In order to identify candidate regulatory genes or pathways functioning in a spectrum of PDX-derived TIC isolated from primary and metastatic sites, we propose to determine first whether TIC derived from either the primary or metastatic site show identical, or different, patterns of activation of signaling networks implicated in TIC function using lentiviral fluorescent reporters specific for signaling pathways and transcription factors implicated in TIC function. We will then identify candidate molecular mechanisms required for TIC activity at the population and single cell levels using RNAseq. In order to determine whether in vivo targeting of TIC-related genes/pathways can augment response to carboplatin, and lead to elimination of different classes of TIC at both the primary and metastatic sites, we will evaluate the ability of FDA-approved agents targeting TIC to augment treatment response alone or in combination with carboplatin at the primary and metastatic sites, and assay the effect of treatment on TIC function in vivo. Results may be used to guide planning and execution of human clinical trials and inform precision medicine efforts.