Open AccessDown‐regulation of cyclooxygenase‐2 expression but up‐regulation of cyclooxygenase‐1 in renal carcinomas of the Eker ( TSC 2 gene mutant) rat model
Author(s) -
Okamoto Toshihiro,
Hara Atsuko,
Hino Okio
Publication year - 2003
Publication title -
cancer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 1347-9032
DOI - 10.1111/j.1349-7006.2003.tb01346.x
Subject(s) - messenger rna , cyclooxygenase , gene expression , microbiology and biotechnology , cell culture , immunohistochemistry , kidney , gene , biology , cancer research , enzyme , immunology , endocrinology , biochemistry , genetics
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. (Cancer Sci 2003; 94: 22–25)