Fig. 1

PTGS pathway expression profiling in colorectal cancer. a Preliminary analysis of a set of nine colorectal tumors by quantitative real-time PCR reveals overall imbalance of gene expression regulation in comparison with adjacent normal colonic mucosae, being most of the genes downregulated. Exceptionably, the expression of genes responsible for PGE₂ biosynthesis is maintained or increased. Absolute expression levels were calculated by the delta Ct method (see “Methods” section). Relative expression corresponds to tumor/adjacent mucosa ratio. b Microarray analysis performed on a cohort of 98 CRC patients (both tumor and adjacent mucosae) and 50 matched healthy donors. As in a, most genes are deregulated, with marked differences not only between tumors and their adjacent normal tissues, but also between normal tissues from patients and healthy individuals