Cadherin-11 (Cad11) for detection of epithelial-mesenchymal transition (EMT) in circulating prostate cancer (PCa) cells.

e22047 Background: CTC are believed to require EMT to metastasize. Cells undergoing EMT may lack or express low levels of epithelial markers such as EpCAM and cytokeratins (CK) and experience a cadherin switch from epithelial to mesenchymal. However, most current detection methods only rely on epithelial markers for enrichment, resulting in failure to recognize other CTC phenotypes. We previously showed that PCa cells expressing the mesenchymal (osteoblast-lineage) marker Cad11 are more likely to home to and colonize bone (Cancer Res 2010). Whether Cad11+ PCa CTC lose CK expression is uncertain. Since Cad11 is an EMT marker relevant to the bone tropism of PCa, we characterized its expression in CTC from patients (pts) with bone metastasis. Methods: Blood from PCa pts (n=86) with different extents of bone involvement was analyzed employing Biocept’s microfluidic CTC technology. For cell capture, we used a PCa CTC-optimized cocktail of antibodies that included epithelial, mesenchymal and putative stem cell ...