The intestinal stem cell signature identifies colorectal cancer stem cells and predicts disease relapse

Using EphB2 or the ISC marker Lgr5, we have FACS-purified and profiled intestinal stem cells (ISCs), crypt proliferative progenitors and late transient amplifying cells to define a gene expression program specific for normal ISCs. A frequent complication in colorectal cancer (CRC) is regeneration of the tumor after therapy. The intestinal stem cell signature predicts disease relapse in CRC and identifies a stem cell-like population that displays robust tumor- initiating capacity in immunodeficient mice as well as long-term self-renewal potential. We FACS purified mouse intestinal crypt cells according to their EphB2 or Lgr5 contents. We used Affymetrix chips to hybridize 2 samples from EphB2 high, 2 samples from EphB2 medium and 2 samples from EphB2 low cells (one sample from each group in a first hybridization on February 2009 plus an additional sample from each group on March 2009). Additionally, we hybridized one sample from Lgr5-EGFP high and one sample from Lgr5-EGFP low cells, obtained from Lgr5-EGFP knock-in mice (Barker et al., 2007).