Development and Evaluation of Highly Specific Monoclonal Antibodies against Human LGR5 for the Identification of Colon Cancer Stem Cells

Abstract

The cancer stem cells is a subpopulation of cancer cells which is responsible for cancer initiation, development and metastasis. Detection and identification of cancer stem cells have been considered as one of the most important objectives for clinical diagnostic and therapeutic purposes. Research evidences indicated that Leucine‐rich repeat containing G‐protein‐coupled receptor 5 (LGR5) is one of the biomarkers specifically expressed on colon cancer stem cells, which is activated by extracellular Wnt molecules to trigger canonical Wnt signaling and gene expression related to cancer development. Therefore, it is critical to develop an LGR5 antibody with great sensitivity and specificity to detect endogenous LGR5 expression in cancer stem cells.In this research, several LGR5 mouse monoclonal antibodies were generated for multiple applications. These LGR5 antibodies are also highly sensitive for flow application on LGR5 stable expression cells and proved to be highly specific with our proprietary high density protein microarray chip assay. Furthermore, we also performed immunohistochemistry assays on colon cancer tissue blocks for diagnostic application. These newly generated LGR5 antibodies could provide new tools for earlier diagnosis and therapeutic guidance on colon cancers.