Description
To examine the role of Rb1 in gastrointestinal (GI) tumors we generated mice with an Apc1638N allele, Rbtm2brn floxed alleles, and a villlin-cre transgene (RBVCA). These mice had reduced median survival due to an increase in tumor incidence and multiplicity in the cecum and the proximal colon; they differed from murine intestinal tumors of the Apc1638N type which normally arise solely in the small intestine. We have examined by micro-array analysis three cecal tumors from these mice (probable adenomas), and compared them to three duodenal tumors (probable adenocarcinomas). Expression profiles of duodenal and cecal tumors relative to each other show unique gene subsets up and down regulated. The two tumor types were subsequently shown to differentially regulate distinct sets of genes over expressed in a majority of human colorectal carcinomas.