Karimi-Busheri Feridoun, Zadorozhny Victoria, Carrier Ewa, Fakhrai Habib
Stem Cell Department, NovaRx Corporation, San Diego, CA 92121, USA.
Cell Tissue Bank. 2013 Jun;14(2):175-86. doi: 10.1007/s10561-012-9315-3. Epub 2012 May 18.
Cryopreservation is a common procedure widely used in biological and clinical sciences. Similar protocols are also applied in preserving cancer stem cells, a field with high promises and challenges. Specific cell surface membrane proteins are considered to be biomarkers of cancer stem cells and they may play a critical role in differentiating stem cells from non stem cells. We have looked at the possible effect of long-term cryopreservation on the molecular integrity of breast MCF7 and lung, A549 and H460, cancer stem cells and to assess if these cells are more sensitive to long-term storage process. We analyzed the expression of CD24 and CD38 as two potent biomarkers of lung cancer stem cells and EpCAM and ALDH that are used as biomarkers of a wide range of cancer stem cells. We also selected three genes essential for the normal functioning of the cells, Fos, MUC1, and HLA. Our results indicate a pattern of down-regulation in the expression of the genes following freezing, in particular among cell surface marker proteins. Global gene expression of the post-thaw breast and lung cancer stem cells also reveals a significant down-regulation in freeze-thaw cells independent from each other. Analyzing the canonical pathways between two populations reveals a significant alteration in the gene expression of the pathways involved in cell cycle, mitosis, and ataxia telangiectasia mutated pathways. Overall, our results indicate that current protocols for long-term storage of lung and breast cancer stem cells may substantially influence the activity and function of genes.
冷冻保存是生物和临床科学中广泛使用的常见程序。类似的方案也应用于保存癌症干细胞，这是一个充满希望和挑战的领域。特定的细胞表面膜蛋白被认为是癌症干细胞的生物标志物，它们可能在区分干细胞和非干细胞方面发挥关键作用。我们研究了长期冷冻保存对乳腺癌MCF7细胞以及肺癌A549和H460癌症干细胞分子完整性的可能影响，并评估这些细胞是否对长期储存过程更敏感。我们分析了作为肺癌干细胞两种有效生物标志物的CD24和CD38以及用作多种癌症干细胞生物标志物的EpCAM和ALDH的表达。我们还选择了细胞正常功能所必需的三个基因，即Fos、MUC1和HLA。我们的结果表明，冷冻后这些基因的表达呈现下调模式，尤其是在细胞表面标记蛋白中。解冻后的乳腺癌和肺癌干细胞的整体基因表达也显示，冻融细胞之间存在显著的相互独立的下调。分析两个群体之间的典型信号通路发现，参与细胞周期、有丝分裂和共济失调毛细血管扩张突变信号通路的基因表达发生了显著改变。总体而言，我们的结果表明，目前用于长期储存肺癌和乳腺癌干细胞的方案可能会对基因的活性和功能产生重大影响。
