Expression of cyclooxygenase-2 parallels expression of interleukin-1beta, interleukin-6 and NF-kappaB in human colorectal cancer

Elevated expression of cyclooxygenase-2 (COX-2), the inducible isoform of prostaglandin H synthase, has been found in several human cancers, including colorectal can-cer (CRC). This appears as a rationale for the chemopre-ventive effects of non-steroidal anti-inflammatory drugs in CRC. However, the reason for COX-2 overexpression is not fully understood. In cell culture experiments, COX-2 can be induced by proinflammatory cytokines, such as interleukin (IL)-1beta and IL-6. A crucial step in this sig-nalling pathway is thought to be activation of transcription factor NF-kB. Based on these findings, we hypothesized an association between COX-2 overexpression and expression of IL-1beta, IL-6 and the NF-kB subunit p65 in human CRC. To test the hypothesis, we performed immunohisto-chemistry for the respective antigens on colorectal cance