%0 Journal Article
%T Epithelial Mesenchymal Transition: A New Insight into the Detection of Circulating Tumor Cells
%A Guislaine Barri¨¨re
%A Michel Tartary
%A Michel Rigaud
%J ISRN Oncology
%D 2012
%R 10.5402/2012/382010
%X Many research groups reported on the relation between circulating tumor cells (CTCs) in peripheral blood and worse prognosis for metastatic cancer patients. These results are based on CTCs counting and did not take into account molecular characteristics of cells. To establish CTCs as a reliable and accurate biological marker, new technologies must be focused on CTC subpopulations: dedifferentiated circulating tumor cells (ddCTCs) arising from epithelial mesenchymal transition (EMT). To select and detect them, different methods have been proposed but none has still reached the goal. Technical progress and translational research are expected to establish CTCs as a real marker. Thus CTC evaluation profiling for each patient will lead to personalize followup and therapy. 1. Introduction Human cells can be classified as either epithelial or mesenchymal and are molecularly characterized by specific expression of genes. In early embryonic morphogenesis, epithelial cells give rise to mesenchymal cells by a reversible reaction, epithelial mesenchymal transition (EMT), between the two phenotypes. Analogous cell status modification is observed in human cancer cells [1¨C3]. Numerous studies have established a link between EMT markers in primary tumor cells and aggressive clinical behaviour [4, 5]. Spread of epithelial tumors to an anatomically distant site seems to occur almost totally via the process of hematogeneous dissemination [6, 7]. Moreover, the initiation of metastasis may be an early event in tumor biology. Circulating tumor cells (CTCs) have been postulated to be critical to this process. In 1869, Ashworth discovered analogous cells to those of a primary tumour in the postmortem patient¡¯s blood and named them Circulating Tumor Cells [8]. Today, the term CTC encompasses all types of cells, which are considered as foreign entities in the blood having some cancerous characters. Evidence has emerged that CTCs present a heterogeneity as the one described for primary tumor cells. Among CTC subpopulations, cancer stem and mesenchymal cells have to be taken into account. We proposed to name these cells dedifferentiated circulating tumor cells (ddCTCs). CTC analysis is generally based on numeration, which is considered to have a prognostic value, and the CellSearch system (Veridex corporation, USA) has been cleared by FDA as an aid to monitor patients with metastatic breast, prostate, and colon cancer [17¨C19]. The surface epithelial cell adhesion molecule (EpCAM) identifies epithelial cells circulating within the blood. Cells lacking CD45 but expressing
%U http://www.hindawi.com/journals/isrn.oncology/2012/382010/