Cancer stem cells (CSCs) are tumor cells that share functional characteristics with normal and embryonic stem cells. CSCs have increased tumor-initiating capacity and metastatic potential and lower sensitivity to chemo- and radiotherapy, with important roles in tumor progression and the response to therapy. Thus, a current goal of cancer research is to eliminate CSCs, necessitating an adequate phenotypic and functional characterization of CSCs. Strategies have been developed to identify, enrich, and track CSCs, many of which distinguish CSCs by evaluating the expression of surface markers, the initiation of specific signaling pathways, and the activation of master transcription factors that control stemness in normal cells. We review and discuss the use of reporter gene systems for identifying CSCs. Reporters that are under the control of aldehyde dehydrogenase 1A1, CD133, Notch, Nanog homeobox, Sex-determining region Y-box 2, and POU class 5 homeobox can be used to identify CSCs in many tumor types, track cells in real time, and screen for drugs. Thus, reporter gene systems, in combination with in vitro and in vivo functional assays, can assess changes in the CSCs pool. We present relevant examples of these systems in the evaluation of experimental CSCs-targeting therapeutics, demonstrating their value in CSCs research.

中文翻译：

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用于识别和表征癌症干细胞的报告基因系统。

癌症干细胞（CSC）是与正常干细胞和胚胎干细胞具有相同功能特征的肿瘤细胞。CSC 具有增加的肿瘤起始能力和转移潜力以及对化疗和放疗的敏感性较低，在肿瘤进展和治疗反应中发挥重要作用。因此，癌症研究当前的目标是消除 CSC，因此需要对 CSC 进行充分的表型和功能表征。已经开发出识别、富集和追踪 CSC 的策略，其中许多策略通过评估表面标记的表达、特定信号通路的启动以及控制正常细胞干性的主转录因子的激活来区分 CSC。我们回顾并讨论了报告基因系统用于识别 CSC 的用途。受乙醛脱氢酶 1A1、CD133、Notch、Nanog 同源盒、性别决定区 Y-box 2 和 POU 5 类同源盒控制的报告基因可用于识别多种肿瘤类型中的 CSC、实时跟踪细胞和筛查毒品。因此，报告基因系统与体外和体内功能测定相结合，可以评估 CSC 库的变化。我们展示了这些系统在实验性 CSC 靶向疗法评估中的相关示例，证明了它们在 CSC 研究中的价值。