Expression of the glucocorticoid receptor in renal cell neoplasms: an immunohistochemical and quantitative reverse transcriptase polymerase chain reaction study.

摘要

Glucocorticoid receptors mediate the action of steroid hormones in a variety of tissues, including the kidney. Our goal was to determine the expression pattern and prognostic significance of glucocorticoid receptor in renal cell neoplasms. Paraffin-embedded microarrays from 200 patients with RCNs including 147 clear cell renal cell carcinomas, 23 papillary, 16 chromophobe renal cell carcinoma, and 14 oncocytomas were analyzed for glucocorticoid receptor expression by immunohistochemistry. Glucocorticoid receptor expression was also quantitated by real-time reverse transcriptase polymerase chain reaction in 45 cases (33 clear cell renal cell carcinomas, 5 chromophobe renal cell carcinomas, and 3 oncocytomas). Strong nuclear glucocorticoid receptor expression was present in normal glomeruli and in the proximal convoluted tubules. Nuclear glucocorticoid receptor expression was found in most clear cell renal cell carcinomas (66%), in 26% of papillary renal cell carcinomas, and in only 6% of chromophobe renal cell carcinomas and 14% of oncocytoma (P < .005). Within the clear cell renal cell carcinoma group, most positive cases (87%) demonstrated strong immunoreactivity (2+ and 3+), whereas only 1 papillary renal cell carcinoma, 1 chromophobe renal cell carcinoma, and none of the oncocytomas showed strong expression. Glucocorticoid receptor alpha messenger RNA expression was significantly higher in clear cell renal cell carcinoma than in chromophobe renal cell carcinoma, oncocytoma, or in the normal kidney. Significantly more frequent glucocorticoid receptor expression was associated with tumors of low nuclear grade (Fuhrman grade 1 and 2) and low stage (stages 1 and 2; P = .0068 and P = .0002). Survival analysis revealed a significant direct correlation between glucocorticoid receptor expression and overall survival in clear cell renal cell carcinoma (P = .01). In summary, strong glucocorticoid receptor expression was most commonly seen in clear cell renal cell carcinoma and only rarely seen in other subtypes. The glucocorticoid receptor expression pattern in RCNs seems to reflect the histogenetic origin of clear cell renal cell carcinoma from the proximal nephron. Finally, glucocorticoid receptor expression proved to be a marker of less aggressive behavior in clear cell renal cell carcinoma.