Established breast cancer stem cell markers do not correlate with in vivo tumorigenicity of tumor-initiating cells
Established breast cancer stem cell markers do not correlate with in vivo tumorigenicity of tumor-initiating cells
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DOI：
10.3892/ijo.2012.1654
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发表时间：
2012-12-01
影响因子：
5.2
通讯作者：
Kubbies, Manfred
中科院分区：
文献类型：
--
作者：
Lehmann, Christian;Jobs, Gabriele;Kubbies, Manfred
人类原发性乳腺癌细胞的肿瘤启动能力是通过体外培养这些细胞作为球体/聚集体来维持的。接种来自这些非粘附培养物的小细胞数量导致小鼠快速形成异种移植物肿瘤。因此，注射来自球体的分化程度更高的单层细胞可显著减缓肿瘤的生长。在我们的研究中，从原发肿瘤中产生了两种乳腺癌细胞系，并将其培养为乳腺球体或其粘附物。我们通过向免疫缺陷小鼠注射一系列稀释剂来检测这些细胞的体内致瘤性。无论细胞系或培养条件如何，每只小鼠接种10(6)个细胞导致肿瘤快速形成。然而，仅注射103个细胞后，仅球形细胞具有高度致瘤性。在体外，我们研究了分化标志物，建立了乳腺CSC标志物并进行了mRNA谱分析。细胞角蛋白5和18在两种单层细胞类型中均增加，表明分化程度更高。所有细胞系均为CD24(-)/CD44(+)，不表达CD133、CD326或E-cadherin。在所有细胞系中均未检测到ALDH1活性。球形细胞中存在维拉帕米敏感的赫斯特侧群体，但与体内的致瘤性无关。m RNA分析未显示相关转录因子的上调。体外细胞周期动力学和体内肿瘤倍增时间在球体和单层培养之间没有差异。我们的数据表明，研究的内在遗传和功能标记并不表明假定的乳腺肿瘤起始细胞的体内肿瘤原性。
The tumor-initiating capacity of primary human breast cancer cells is maintained in vitro by culturing these cells as spheres/aggregates. Inoculation of small cell numbers derived from these non-adherent cultures leads to rapid xenograft tumor formation in mice. Accordingly, injection of more differentiated monolayer cells derived from spheres results in significantly decelerated tumor growth. For our study, two breast cancer cell lines were generated from primary tumors and cultured as mammospheres or as their adherent counterparts. We examined the in vivo tumorigcnicity of these cells by injecting serial dilutions into immunodeficient mice. Inoculation of 10(6) cells per mouse led to rapid tumor formation, irrespective of cell line or culture conditions. However, after injection of only 103 cells, solely sphere cells were highly tumorigenic. In vitro, we investigated differentiation markers, established breast CSC markers and conducted mRNA profiling. Cytokeratin 5 and 18 were increased in both monolayer cell types, indicating a more differentiated phenotype. All cell lines were CD24(-)/CD44(+) and did not express CD133, CD326 or E-cadherin. ALDH1 activity was not detectable in any cell line. A verapamil-sensitive Hoechst side population was present in sphere cells, but there was no correlation with tumorigenicity in vivo. m RNA profiling did not reveal upregulation of relevant transcription factors. In vitro cell cycle kinetics and in vivo tumor doubling times displayed no difference between sphere and monolayer cultures. Our data indicate that intrinsic genetic and functional markers investigated are not indicative of the in vivo tumori-genicity of putative breast tumor-initiating cells.