Flow cytometric detection of circulating tumor cells using a candidate stem cell marker, p75 neurotrophin receptor (p75NTR)

Abstract

The most widely studied detection for circulating tumor cells (CTCs) in peripheral blood of cancer patients has been based on immunomagnetic enrichment using antibodies against epithelial cell adhesion molecule (EpCAM), which is overexpressed in epithelial cells. A neurotrophin receptor p75 (p75NTR) is expressed in a candidate stem cell fraction in esophageal squamous cell carcinoma (ESCC), which shows significantly higher colony formation, enhanced tumor formation in mice, along with strong expression of epithelial mesenchymal transition-related genes. Here, we describe a method to detect CTCs in ESCC based on the combined expression of EpCAM and p75NTR using flow cytometry, demonstrating the feasibility of expression analysis of multiple cell surface markers in viable cells.