Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2017 Jun 27;8(42):72054-72068.
doi: 10.18632/oncotarget.18679. eCollection 2017 Sep 22.

Direct comparison study of DNA methylation markers in EpCAM-positive circulating tumour cells, corresponding circulating tumour DNA, and paired primary tumours in breast cancer

Maria Chimonidou  1 , Areti Strati  1 , Nikos Malamos  2 , Sophia Kouneli  2 , Vassilis Georgoulias  3 , Evi Lianidou  1
Affiliations

Direct comparison study of DNA methylation markers in EpCAM-positive circulating tumour cells, corresponding circulating tumour DNA, and paired primary tumours in breast cancer

Maria Chimonidou et al. Oncotarget. .

Abstract

Circulating Tumour Cells (CTCs) and circulating tumour DNA (ctDNA) represent a non-invasive liquid biopsy approach for the follow-up and therapy management of cancer patients. We evaluated whether DNA methylation status in CTCs and ctDNA is comparable and whether it reflects the status of primary tumours. We compared the methylation status of three genes, SOX17, CST6 and BRMS1 in primary tumours, corresponding CTCs and ctDNA in 153 breast cancer patients and healthy individuals, by using real time methylation specific PCR. We report a clear association between the EpCAM-positive CTC-fraction and ctDNA for SOX17 promoter methylation both for patients with early (P = 0.001) and metastatic breast cancer (P = 0.046) but not for CST6 and BRMS1. In early breast cancer, SOX17 promoter methylation in the EpCAM-positive CTC-fraction was associated with CK-19 mRNA expression (P = 0.006) and worse overall survival (OS) (P = 0.044). In the metastatic setting SOX17 promoter methylation in ctDNA was highly correlated with CK-19 (P = 0.04) and worse OS (Ρ = 0.016). SOX17 methylation status in CTCs and ctDNA was comparable and was associated with CK-19 expression but was not reflecting the status of primary tumours in breast cancer. DNA methylation analysis of SOX17 in CTCs and matched ctDNA provides significant prognostic value.

Keywords: breast cancer; circulating tumour DNA; circulating tumour cells; liquid biopsy; methylation specific PCR.

PubMed Disclaimer

Conflict of interest statement

CONFLICTS OF INTEREST None.

Figures

Figure 1
Figure 1. Workflow of the study
Figure 2
Figure 2
Heat map of SOX17, CST6 and BRMS1 promoter methylation and CK-19 expression in the EpCAM-positive CTC-fraction, and ctDNA in matched samples of patients with: (A) operable breast cancer (n = 92), (B) verified metastasis (n = 61), and (C) all samples including available FFPEs (n = 75). Color code: green: non-methylated/no-relapse/alive, red: methylated/relapse/dead.
Figure 3
Figure 3
Kaplan-Meier estimates of (A) Disease-free interval (DFI) in months for early breast cancer patients in respect to BRMS1 promoter methylation status in FFPEs (P = 0.042), (B) Overall survival (OS) in months for early breast cancer patients with clinically confirmed metastasis, in respect to SOX17 promoter methylation status in CTCs (P = 0.044), (C) Overall survival (OS) in months for breast cancer patients with clinically confirmed metastasis, in respect to the methylation of at least two genes in ctDNA (P = 0.011), (D) Overall survival (OS) in months for breast cancer patients with clinically confirmed metastasis, in respect to SOX17 promoter methylation status in ctDNA (P = 0.016).
See this image and copyright information in PMC

References

    1. Alix-Panabières C, Pantel K. Circulating tumor cells: liquid biopsy of cancer. Clin Chem. 2013;59:110–18. https://doi.org/10.1373/clinchem.2012.194258 - DOI - PubMed
    1. Lianidou ES, Mavroudis D, Georgoulias V. Clinical challenges in the molecular characterization of circulating tumour cells in breast cancer. Br J Cancer. 2013;108:2426–32. https://doi.org/10.1038/bjc.2013.265 - DOI - PMC - PubMed
    1. Schlange T, Pantel K. Potential of circulating tumor cells as blood-based biomarkers in cancer liquid biopsy. Pharmacogenomics. 2016;17:183–86. https://doi.org/10.2217/pgs.15.163 - DOI - PubMed
    1. Lianidou ES. Molecular characterization of circulating tumor cells: holy Grail for personalized cancer treatment? Clin Chem. 2014;60:1249–51. https://doi.org/10.1373/clinchem.2014.230144 - DOI - PubMed
    1. Lianidou ES, Strati A, Markou A. Circulating tumor cells as promising novel biomarkers in solid cancers. Crit Rev Clin Lab Sci. 2014;51:160–71. https://doi.org/10.3109/10408363.2014.896316 - DOI - PubMed