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.
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.
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.
These data indicate that COX-2 is up-regulated in human thyroid cancer, but not in benign thyroid nodules, and suggest that COX-2 expression may serve as a marker of malignancy in thyroid nodules.
Collectively, these results suggest that overexpression of COX-2 is a frequent phenomenon in hypopharyngeal carcinoma and may play a role in tumorigenesis of this cancer.
This targeting method was then used to direct the expression of inducible forms of caspases 3 and 9 to Cox-2-overexpressing cancer cells of the bladder and prostate.
Aberrant upregulation of COX-2 enzyme resulting in accumulation of PGE2 in a cancer cell environment is a marker for progression of many cancers, including breast cancer.
Evidence includes a direct relationship between COX-2 expression and cancer incidence in humans and animal models, increased tumorigenesis after genetic manipulation of COX-2, and significant anti-tumor properties of non-steroidal anti-inflammatory drugs in animal models and in some human cancers.
Taken together, these results suggest that inhibition of COX-2 is one of the mechanisms by which the methanolic extract of adlay seed inhibits cancer growth and prevents lung tumorigenesis.
Several lines of evidence suggest that the cyclooxygenase enzymes (specifically COX-2) might be an important molecular target for the intervention of cancer at both early and late stages of some cancers, providing an opportunity for both cancer prevention and therapy.