Overexpression of cyclooxygenase-2 (COX-2) has been implicated in carcinogenesis of human colorectal cancer which is one of the leading types of cancer in Western countries.
The results provide direct genetic evidence that COX-2 plays a key role in tumorigenesis, and indicate that COX-2-selective inhibitors can be a new class of therapeutic agents for colorectal polyposis and cancer.
Overexpression of COX-2 in cancer tissues compared with matched non-cancerous tissues was found in 70% of cases and was significantly associated with lymphatic involvement, lymph node metastasis and advanced tumor stage.
In the following article, the phenotypes of the two Ptgs (genes coding for COX-1 and COX-2) knockouts are summarized, and recent studies to investigate the effects of COX deficiency on cancer susceptibility, inflammatory response, gastric ulceration, and female reproductive processes are discussed.
Recent studies have shown increased levels of cyclooxygenase-2 (COX-2) in a variety of human malignancies including hepatocellular carcinoma (HCC), but little is known about the prognostic value of COX-2 in HCC or its associated nontumor liver tissue.
Cyclooxygenase-2 (COX-2) is overexpressed in various types of human malignancies including squamous cell carcinomas (SCCs) of the esophagus, but little is known about COX-2 expression in premalignant esophageal squamous dysplasia.
We investigated the expression of COX-2 and prostaglandin (PG) E((2)) production in two human skin epidermal cancer cell lines: cutaneous squamous cell carcinoma, HSC-5, and eccrine carcinoma, EcCa.
Both gastrin and CCK(B)-R mRNA were detected by RT-PCR in the cancer tissue and similarly COX-2 mRNA and protein were found in most of cancers and in the HP infected antral mucosa but not in HP eradicated patients in whom only cancer tissue but not gastric mucosa expressed COX-2.
Both gastrin and CCKB-R mRNA were detected in the cancer tissue and at the resection margin and similarly COX-2 mRNA was expressed in most cancers and resection margin but not in bronchial mucosa where only COX-1 was found.
Recent studies have shown overexpression of cyclooxygenase 2 (COX 2) and 5-lipoxygenase (5-lipox) in exocrine pancreatic carcinomas, suggesting a potential role of the arachidonic acid (AA) cascade in the regulation of this cancer type.
Cyclooxygenase (COX)-2 expression is elevated in some malignancies; however, information is scarce regarding COX-2 contributions to the development of prostate cancer and its regulation by inflammatory cytokines.
Two Cox genes have been cloned, and expression of Cox-2 mRNA and protein has been shown to be elevated in several human malignancies and in animal models of carcinogenesis.
We propose that pretreatment with selective Cox-2 inhibitors may be useful in the prevention of multidrug resistance in response to cancer chemotherapy and should be further evaluated.
These data suggest that COX-2 expression might regulate carcinogenesis of bile duct epithelial cells in inflammatory regions and tumor progression in this cancer.
Gastrin and CCK(B)-R mRNA were detected in the cancer tissue and the resection margin and similarly COX-2 mRNA was expressed in most of cancers and their resection margin but not in intact colonic mucosa where only COX-1 was detected.
Taken together, our results suggest that overexpression of mPGES in addition to COX-2 contributes to increased amounts of PGE(2) in colorectal adenomas and cancer.