Molecular integrity and global gene expression of breast and lung cancer stem cells under long-term storage and recovery

Victoria Zadorozhny,Habib Fakhrai,Feridoun Karimi-Busheri,Ewa Carrier

doi:10.1007/s10561-012-9315-3

Victoria Zadorozhny, Habib Fakhrai

Open Access

https://doi.org/10.1007/s10561-012-9315-3

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Abstract

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.

Highlights

Cryopreservation has played a significant role in the advancement of modern science, in particular in biological science, since its application in mid twentieth century by James Lovelock (Mazur 1970)
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 aldehyde dehydrogenase (ALDH) that are used as biomarkers of a wide range of cancer stem cells

Summary

Introduction

Cryopreservation has played a significant role in the advancement of modern science, in particular in biological science, since its application in mid twentieth century by James Lovelock (Mazur 1970). Cancer stem cells known as tumor-initiating cells is an emerging field of study that has extensively expanded our vision on cancer development, progression and metastasis (Karimi-Busheri et al 2010a, b; Pardal et al 2003; Zhang and Rosen 2006; O’Brien et al 2009; Monteiro and Fodde 2010) These cells have been isolated from almost all malignancies including hematopoietic, breast, brain, pancreas, and prostate cancer (Notta et al 2011; Al-Hajj et al 2003; Eyler et al 2011; Lonardo et al 2010; Lang et al 2009). Cancer stem cells have been shown to produce cytokines, chemokines, angiogenic factors (Levina et al 2008; Hermann et al 2007), and possess up-regulated signaling cascades essential for cancer metastasis, including hedgehog, epidermal growth factor receptor, NOTCH, and Bmi-1 (Mimeault and Batra 2010; Simeone 2008)

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