title: Down-regulation of cyclooxygenase-2 expression but up-regulation of cyclooxygenase-1 in renal carcinomas of the Eker (TSC2 gene mutant) rat model.
abstract: Although it is generally accepted that cyclooxygenase (Cox)-2 is overexpressed in carcinomas, few studies have examined Cox-2 expression in renal carcinoma (RC). The Eker rat RC is an example of a Mendelian dominantly inherited carcinoma, and in the present study, expression of Cox-2 in the Eker rat RC was examined. Reverse transcription polymerase chain reaction indicated constitutive expression of Cox-2 mRNA in the normal control kidney and non-tumor part of Eker rat kidney. Unexpectedly, expression of Cox-2 mRNA was down-regulated in four Eker RCs from two Eker rats, and in the cell line Lk9ds. Immunohistochemical analysis failed to reveal Cox-2 protein staining in Eker RCs. As a control to Cox-2 expression, Cox-1 expression was examined. Interestingly, in contrast to the down-regulated Cox-2 expression, Cox-1 mRNA expression was induced in these four Eker RCs and cell lines. Cox-2 and Cox-1 expression were further examined in six additional Eker RCs. In total, Cox-2 mRNA expression was down-regulated in eight out of ten Eker RCs and cell lines, while Cox-1 mRNA expression was up-regulated in nine out of ten Eker RCs and cell lines.
authors.affiliation: Research Laboratories, Nippon Chemiphar Co., Ltd., Saitama 341-0005.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Okamoto
authors.forename: Atsuko
authors.initials: A
authors.lastname: Hara
authors.forename: Okio
authors.initials: O
authors.lastname: Hino
mesh_terms: D000818:Animals; D002292:Carcinoma, Renal Cell / Q000201:enzymology* / Q000235:genetics; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D004195:Disease Models, Animal; D004790:Enzyme Induction; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D005799:Genes, Dominant; D007527:Isoenzymes / Q000096:biosynthesis* / Q000235:genetics; D007668:Kidney / Q000201:enzymology; D007680:Kidney Neoplasms / Q000201:enzymology* / Q000235:genetics; D008565:Membrane Proteins; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D012334:RNA, Neoplasm / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D011922:Rats, Mutant Strains; D012097:Repressor Proteins / Q000235:genetics; D014402:Tuberous Sclerosis; D000077005:Tuberous Sclerosis Complex 2 Protein; D014407:Tumor Cells, Cultured / Q000201:enzymology; D025521:Tumor Suppressor Proteins
chemical_list: D007527:Isoenzymes; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D012097:Repressor Proteins; C000624655:Tsc2 protein, rat; D000077005:Tuberous Sclerosis Complex 2 Protein; D025521:Tumor Suppressor Proteins; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases; C496513:Ptgs1 protein, rat