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Cryobiology. 2010 Jun;60(3):308-14. doi: 10.1016/j.cryobiol.2010.02.005. Epub 2010 Feb 21.
Cancer stem cells are believed to be the driving force behind tumor progression and development. Despite extensive studies on the effects of cryopreservation on embryonic and hematopoietic stem cells there is only limited data that directly deals with in the cryopreservation of cancer stem cells. In this study, we looked at the effect of cryopreservation on breast cancer progenitor cells known as mammospheres, which are derived from the MCF7 breast carcinoma cell line. We focused on the effect of cryopreservation on the cell biology and function of tumor-initiating cells using a standard method of cryopreservation with 15% dimethyl sulfoxide (Me(2)SO). Cell proliferation and survival was analyzed by alamarBlue solution on cryopreserved cells stored for 1-12 weeks and also by the expression of Ki-67. To assess self-renewal, single cells were harvested by limiting dilution procedure and wells were scored once a week. In order to investigate senescence, the activity of beta-galactosidase was detected by histochemical staining. Our results indicate that cryopreservation of breast cancer initiating cells will not reduce the ability of the cells to proliferate following cryopreservation storage for up to 12 months. Similarly, self-renewal, a unique property of stem cells, was shown to be maintained during cryopreservation. In contrast, cryopreservation of the mammospheres significantly increases the rate of senescence-mediated pathways. These data suggest that although cryopreservation of tumor-initiating cells is feasible but further studies are necessary to achieve a trustable repository of tumor-initiating cells and the design of new therapeutic measures to specifically target these cells.
癌症干细胞被认为是肿瘤进展和发展的驱动力。尽管对冷冻保存对胚胎和造血干细胞的影响进行了广泛的研究，但只有有限的数据直接涉及癌症干细胞的冷冻保存。在这项研究中，我们研究了冷冻保存对乳腺癌祖细胞（称为乳腺球体）的影响，乳腺球体来源于 MCF7 乳腺癌细胞系。我们专注于冷冻保存对肿瘤起始细胞的细胞生物学和功能的影响，使用 15％二甲亚砜（Me 2 SO）的标准冷冻保存方法。通过 alamarBlue 溶液分析冷冻保存细胞的细胞增殖和存活，这些细胞在 1-12 周内储存，并通过 Ki-67 的表达进行分析。为了评估自我更新，通过有限稀释程序收获单细胞，并每周评分一次。为了研究衰老，通过组织化学染色检测β-半乳糖苷酶的活性。我们的结果表明，乳腺癌起始细胞的冷冻保存不会降低细胞在冷冻保存储存长达 12 个月后的增殖能力。同样，自我更新是干细胞的独特特性，在冷冻保存期间得到维持。相比之下，乳腺球体的冷冻保存显著增加了衰老介导的途径的速率。这些数据表明，虽然冷冻保存肿瘤起始细胞是可行的，但需要进一步的研究来实现肿瘤起始细胞的可靠储存库，并设计针对这些细胞的新治疗措施。
