Visualization and characterization of cancer stem-like cells in cervical cancer
Visualization and characterization of cancer stem-like cells in cervical cancer
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DOI：
10.3892/ijo.2014.2670
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发表时间：
2014-12-01
影响因子：
5.2
通讯作者：
Ogawa, Kazuhiko
中科院分区：
文献类型：
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作者：
Hayashi, Kazuhiko;Tamari, Keisuke;Ogawa, Kazuhiko
肿瘤干细胞(CSCs)由其分化能力、自我更新能力和维持增殖能力决定，已在包括宫颈癌在内的许多肿瘤中被发现。目前的研究通过几种特定的生物标志物来识别宫颈干细胞，然而，在体外和体内实时监测宫颈干细胞是困难的。最近的研究报道了利用绿色荧光蛋白ZsGreen与可被蛋白酶体破坏的退化基序鸟氨酸脱羧酶(ODC)融合，在乳腺癌和胶质瘤中显示CSCs。因此，CSCs具有较低的26S蛋白酶体活性，而非CSCs具有较高的26S蛋白酶体活性。因此，通过积聚荧光的Zs绿蛋白来观察CSCs是可能的。在这项研究中，我们使用两个人宫颈癌细胞系CaSki和HeLa来研究评估CSCs的光学成像参数。我们将群体定义为具有高和低ZsGreen-cODC(分别为高和低Zs)表达水平的细胞类型。球体形成分析结果表明，高Zs群体的自我更新能力显著高于低Zs群体。致瘤性分析证实，高Zs人群比低Zs人群表现出更高的致瘤潜力。克隆存活实验和四唑盐染色实验分别证实HeLa和CaSki细胞高Zs群体的放射抗性和CaSki细胞高Zs群体的化疗抗性。这些结果表明，HeLa和CaSki细胞系的高Zs群体都具有CSC样特性和治疗耐药性。总之，我们成功地使用荧光蛋白系统显示了CSC样细胞。
Cancer stem cells (CSCs), defined by their differentiation capacity, self-renewal capacity, and maintenance of proliferation, have been identified in many tumors, including cervical cancer. Current studies identify CSCs by several specific biomarkers; however, it is difficult to monitor cervical CSCs in real-time in vitro and in vivo. Recent research reported the visualization of CSCs in breast cancer and gliomas using green fluorescent protein, ZsGreen, fused to a degron motif ornithine decarboxylase (ODC), which is destroyed by proteasomes. Accordingly, CSCs have low 26S proteasome activity, whereas non-CSCs have high 26S proteasome activity. Therefore, it is possible to observe CSCs by their accumulation of the fluorescent Zs Green protein. In this study, we investigated optical imaging parameters to evaluate CSCs using two human cervical cancer cell lines: CaSki and HeLa. We defined populations as cell types having high- and low ZsGreen-cODC (high- and low-Zs, respectively) expression levels. The results of a sphere-forming assay revealed that the self-renewal ability of the high-Zs population was significantly higher than that of the low-Zs population. A tumorigenicity assay confirmed that the high-Zs population exhibited higher tumorigenic potential than the low-Zs population. The radioresistance of the high-Zs population of both HeLa and CaSki cells and the chemoresistance of the high-Zs population of CaSki cells were confirmed by a clonogenic survival assay and the tetrazolium dye assay, respectively. These results indicate that high-Zs populations of both the HeLa and CaSki cell lines possess CSC-like properties and therapeutic resistance. In conclusion, we successfully visualized CSC-like cells using a fluorescent protein system.