Colorectal Cancer Cell Lines aCGH

Somatic DNA alteration underlies tumor development and progression, and gives rise to tumors with diverse genetic contexts. Here, we identify in a collection of 29 colorectal cancer cell lines and 226 primary colorectal tumors recurrent amplification of chromosome 13, an alteration highly restricted to colorectal-derived cancers. A minimal region of amplification on 13q12.2 pinpoints caudal type homeobox transcription factor CDX2, a master regulator of anterior-posterior patterning, midgut development, and intestinal epithelial cell differentiation and maintenance. In contrast to its described role as a colorectal tumor suppressor, we show that in the context of genomic amplification, CDX2 is required for proliferation and anchorage-independent growth of colorectal cancer cells. By genome-wide expression and location analysis, we reveal that CDX2 directly promotes expression of Wnt pathway genes. Further results suggest that CDX2 induces expression of intestinal differentiation markers and modulates b-catenin transcriptional activity. These data characterize CDX2 as a novel lineage-survival oncogene deregulated in colorectal cancer. comparative genomic hybridization by array