Expression data from colorectal tumors of mice

Myeloid cells can inhibit the anti-tumor responses of T cells. The mechanism for this cross-talk is not fully elucidated but is known to require STAT3. We employed mice with conditional deletion of STAT3 in myeloid cells to investigate myeloid STAT3 functions in colitis-associated colorectal tumors in mice. We found that STAT3 is required for suppression of anti-tumor T cell responses in the tumor stroma and identified several signaling pathways in tumor cells that might be implicated in immune escape. Azoxymethane/Dextransulfate (AOM/DSS)-induced colitis-associated colorectal tumors were obtained from wild-type mice and mice with conditional deletion of STAT3 in myeloid cells. Tumor and stroma tissue from colorectal tumors was separated by laser-capture-microdissection and corresponding RNA was used for Affymetrix microarray experiments to identify stromal changes that depent on STAT3 signaling in the myeloid compartment.