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

项目总结 我们和其他人已经证明，一组能够再生新肿瘤的肿瘤细胞亚群，有不同的名称 作为肿瘤起始细胞(TIC)或“癌症干细胞”(CSC)，对当前的系统性 与肿瘤大部分相关的化疗和放射治疗。因此，我们工作的指导前提是 过去十年，对TIC生存或功能所需过程的治疗靶向是否将允许 消除原发和转移部位的这种细胞，从而增强对电流的反应 系统性治疗。然而，从几个使用当前细胞表面标记的实验室中可以明显看出， Wnt、Hedgehog和STAT3介导的酶活性标记和慢病毒信号报告 信号表明，TIC不仅在肿瘤之间是异质性的，而且表现出不同的行为、治疗 在给定的肿瘤模型中，原始和转移部位的反应和报告基因的表达。因此， 了解肿瘤内部和跨肿瘤的TIC类型的多样性以及了解 这些细胞在原发灶和转移灶之间的功能差异，以便有效地靶向它们- 特别是在“三阴性”乳腺癌(TNBC)方面，目前还没有批准的靶向治疗方法。 我们假设在TNBC中存在分子上不同类型的TIC。因此，差异化 对个体化化疗的反应部分取决于特定肿瘤中存在的TIC的类别。如果 是的，我们进一步断言，识别和定位特定于类的TIC函数可能有助于克服 化疗耐药。 为了确定在PDX衍生的TIC谱中起作用的候选调控基因或通路 从原发和转移部位分离出来，我们建议首先确定TIC是否来源于 原发灶或转移灶表现出相同或不同的信号网络激活模式 慢病毒特异性信号通路和转录因子荧光报告系统的TIC功能 与TIC功能有关。然后，我们将确定TIC活性所需的候选分子机制 用RNAseq. 为了确定体内靶向TIC相关基因/通路是否可以增强对 卡铂，并导致消除不同类别的TIC在原发灶和转移灶，我们将 评估FDA批准的针对TIC的药物单独或联合应用增强治疗反应的能力 原发灶和转移灶联合卡铂治疗，观察治疗对TIC的影响 在体内发挥作用。结果可用于指导人类临床试验的计划和执行，并提供信息 精准医疗发力。

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.