CXCR4 EXPRESSION IN DIFFERENT SUBSETS OF CTCs AND SINGLE (DETACHED) BREAST CANCER CELLS

The aim of this study was to assess CXCR4 expression in different subsets of CTCs and single (detached) breast cancer cells.Materials and methods. Thirty five patients with invasive breast carcinoma of no specialtype (IC NST) (T1-4N0-2M0), between 29 and 69 years of age were included in this study. Different subsets of CTCs with CXCR4 expression were evaluated by flow cytometry. A confocal microscopy was used to assess CXCR4 expression in different subsets of single (detached) cancer cells in breast tissue.Results. The CXCR4 was expressed in CTCs without stem-like and EMT phenotype, in CTCs with EMT but not stem markers and in stem-like CTCs without EMT features. In all blood samples, the CXCR4 expression in CTCs with stem-like and EMT phenotype was absent. In breast tumor the CXCR4 was expressed in the non stemlike single (detached) breast cancer cells with EMT features, in the single (detached) breast cancer cells with stem and EMT features. In all tumor samples the stem-like or non stem-like single (detached) breast cancer cells without EMT features were absent.Conclusions. Different subsets of the CTCs exhibited CXCR4. The CXCR4 expression did not depend on the presence or absence of stem or/and EMT features in tumor cells. We showed that some subsets of single (detached) breast cancer cells in the primary tumor were characterized by the ability to express CXCR4 and may be a source of the respective CTC subsets.