Abstract
Circulating tumour cells (CTCs) can provide valuable prognostic information in a number of epithelial cancers. However, their detection is hampered due to their molecular heterogeneity, which can be induced by the epithelial-mesenchymal transition (EMT) process. Therefore, current knowledge about CTCs from clinical samples is often limited due to an inability to isolate wide spectrum of CTCs phenotypes. In the current work, we aimed at isolation and molecular characterization of CTCs with different EMT status in order to establish their clinical significance in early breast cancer patients. We have obtained CTCs-enriched blood fraction from 83 breast cancer patients in which we have tested the expression of epithelial, mesenchymal and general breast cancer CTCs markers (MGB1/HER2/CK19/CDH1/CDH2/VIM/PLS3), cancer stem cell markers (CD44, NANOG, ALDH1, OCT-4, CD133) and cluster formation gene (plakoglobin). We have shown that in the CTCs-positive patients, epithelial, epithelial-mesenchymal and mesenchymal CTCs markers were detected at a similar rate (in 28%, 24% and 24%, respectively). Mesenchymal CTCs were characterized by the most aggressive phenotype (significantly higher expression of CXCR4, uPAR, CD44, NANOG, p < 0.05 for all), presence of lymph node metastases (p = 0.043), larger tumour size (p = 0.023) and 7.33 higher risk of death in the multivariate analysis (95% CI 1.06–50.41, p = 0.04). Epithelial-mesenchymal subtype, believed to correspond to highly plastic and aggressive state, did not show significant impact on survival. Gene expression profile of samples with epithelial-mesenchymal CTCs group resembled pure epithelial or pure mesenchymal phenotypes, possibly underlining degree of EMT activation in particular patient’s sample. Molecular profiling of CTCs EMT phenotype provides more detailed and clinically informative results, proving the role of EMT in malignant cancer progression in early breast cancer.
Highlights
Circulating tumour cells (CTCs) are detected in peripheral blood and are prognostic in patients with different solid tumours including breast [1,2], colorectal [3,4], lung [5], prostate [6] cancer and hepatocellular carcinoma [7]
The best known phenomenon, which is involved in introducing such heterogeneity is epithelial-mesenchymal transition (EMT), a physiological process hijacked by cancer cells
Results of further gene expression analysis of the MGB1 and/or HER2-positive preamplified samples allowed for classification into three EMT classes—epithelial (CK19- and/or CDH1-positive), mesenchymal (VIM- and/or CDH2- and/or Plastin 3 (PLS3)-positive) and epithelial-mesenchymal group in which both epithelial (CK19 and/or CDH1) and mesenchymal markers (VIM and/or CDH2 and/or PLS3) were co-expressed
Summary
Circulating tumour cells (CTCs) are detected in peripheral blood and are prognostic in patients with different solid tumours including breast [1,2], colorectal [3,4], lung [5], prostate [6] cancer and hepatocellular carcinoma [7]. The dynamically developing field of CTCs detection and characterization revealed that CTCs exhibit inter- and intra-patient heterogeneity, in terms of markers that are used to define CTCs presence [14,17]. This heterogeneity can impact ability to detect CTCs, which is especially important in early stage disease, when CTCs are rare (1–2 cells/7.5 mL of blood) and could be lost due to lack of specific marker expression [1,18,19]. Upon disease progression fraction of mesenchymal CTCs increases [17] and is linked with the development of distant metastases [24]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
