Expression data from epithelial cells during the process of multistep pancreatic carcinogenesis

The host antitumor immunity changes drastically during carcinogenesis. Intraductal papillary-mucinous neoplasm (IPMN) of the pancreas is a precursor lesion of pancreatic cancer and progresses according to adenoma-carcinoma sequence. We found that the host antitumor immune reaction changes from an immune response to immune tolerance between intraductal papillary-mucinous adenoma (IPMA) and intraductal papillary-mucinous carcinoma (IPMC). In order to determine molecules affecting intraepithelial DC infiltration in IPMNs during multistep carcinogenesis, we examined the gene-expression profiles of entire transcripts of neoplastic cells at different stages. We collected normal and neoplastic epithelial cells from frozen tissue sections (normal main pancreatic duct, IPMA, IPMC, and invasive carcinoma originating in IPMN) by laser microdissection, extracted total RNA from them, and analyzed their gene expression profiles using Affymetrix microarrays.