Expression data from human non-affected and cancerous colon

Innate lymphoid cells (ILCs) have the ability to sense and amplify inflammatory signals, and have been shown to exert bi-directional regulation with T helper cells in mice. However, how crosstalk between ILCs and CD4+ T cells influences immune function in humans is unknown. We observed that human intestinal ILCs co-localize with T cells in healthy and colorectal cancer tissue and display elevated HLA-DR expression in tumor and tumor-adjacent areas. Although mostly lacking co-stimulatory molecules ex vivo, intestinal and peripheral blood ILCs acquired antigen-presenting characteristics triggered by inflammasome-associated cytokines IL-1β and IL-18. This effect was strongly inhibited by the anti-inflammatory cytokine TGFβ. Here we wanted to investigate how the microenvironment in the colon would change in the cancer setting. We used microarrays to profile global gene expression changes in the human colon, extending from non-affected tissue with increasing proximity to cancerous tissue. Non-affected, tumor border and central tumor tissue was obtained from 3 patients undergoing colon cancer surgery. Muscle and adipose tissues were removed and a small piece (approximately 2x2mm) of the remaining non-affected as well as cancer-associated colon tissue was used for RNA extraction and hybridization on Affymetrix microarrays.