Monoclonal Antibodies Against Lgr5 Identify Human Colorectal Cancer Stem Cells

• Published in: Stem cells (Dayton, Ohio) Vol. 30; no. 11; pp. 2378 - 2386
• Main Authors: Kemper, Kristel, Prasetyanti, Pramudita R., De Lau, Wim, Rodermond, Hans, Clevers, Hans, Medema, Jan Paul
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01-11-2012; Oxford University Press
• Subjects: Animals; Antibodies, Monoclonal, Murine-Derived - chemistry; Antibodies, Monoclonal, Murine-Derived - immunology; Antibody; Biomarkers, Tumor - genetics; Biomarkers, Tumor - immunology; Biomarkers, Tumor - metabolism; Cancer stem cell; Cell Differentiation; Cell Separation; Cell Transformation, Neoplastic - metabolism; Colorectal; Colorectal cancer; Colorectal Neoplasms - pathology; Epitope Mapping; Flow Cytometry; Fluorescent Antibody Technique, Indirect; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; Lgr5; Male; Medical research; Mice; Mice, Nude; Mucin-2 - metabolism; Neoplasm Transplantation; Neoplastic Stem Cells - metabolism; Neoplastic Stem Cells - physiology; Rats; Receptors, G-Protein-Coupled - genetics; Receptors, G-Protein-Coupled - immunology; Receptors, G-Protein-Coupled - metabolism; Spheroids, Cellular - metabolism; Stem cells; Tumor Cells, Cultured; Wnt Signaling Pathway
• ISSN: 1066-5099; 1549-4918
• DOI: 10.1002/stem.1233

In colorectal cancer (CRC), a subpopulation of tumor cells, called cancer stem cell (CSC) fraction, is suggested to be responsible for tumor initiation, growth, and metastasis. The search for a reliable marker to identify these CSCs is ongoing as current markers, like CD44 and CD133, are more broadly expressed and therefore are not highly selective and currently also lack function in CSC biology. Here, we analyzed whether the Wnt target Lgr5, which has earlier been identified as a marker for murine intestinal stem cells, could potentially serve as a functional marker for CSCs. Fluorescence‐activated cell sorting‐based detection of Lgr5, using three newly developed antibodies, on primary colorectal tumor cells revealed a clear subpopulation of Epcam+Lgr5+ cells. Similarly, primary CRC‐derived spheroid cultures, known to be enriched for CSCs, contain high levels of Lgr5+ cells, which decrease upon in vitro differentiation of these CSCs. Selection of the Lgr5high CRC cells identified the clonogenic fraction in vitro as well as the tumorigenic population in vivo. Finally, we confirm that Lgr5 expression is dependent on the Wnt pathway and show that Lgr5 overexpression induces clonogenic growth. We thus provide evidence that Lgr5 is, next to a functional intestinal stem cell marker, a selective marker for human colorectal CSCs. STEM CELLS2012;30:2378–2386