Comparison of gene expression patterns between Lgr5 positive cells in adenomas and small intestine

The generation of the Lgr5_EGFP_ires_CreERT2 knock-in mouse allows marking of Lgr5 positive cells of different tissues by GFP expression. Here we use these mice to sort GFP positive cells from intestinal adenomas and compare those to GFP positive cells from normal small intestine. In Lgr5_EGFP_ires_CreERT2 knock-in mice, GFP is expressed under the control of the Lgr5 promoter, leading to high GFP levels in Lgr5 positive cells (GFP-high). In normal small intestine, GFP-high cells mark crypt base columnar cells, the stem cells of small intestine. Intestinal adenomas can be generated in these mice when crossed to Apc_fl/fl mice by inducing Apc deletion through the Lgr5 driven Cre. We isolated GFP-high cells both from intestinal adenomas and normal small intestine of Lgr5-ki mice without the Apc_fl/fl allele and compared them to each other on 4X44K Agilent Whole Mouse Genome dual colour Microarrays (G4122F). Three independent sorts were performed and RNA of GFP-high adenoma cells hybridized directly against RNA of GFP-high cells from normal small intestine in three dye swap experiments, resulting in six individual arrays.