Expression of thyroid hormone receptors is disturbed in human renal clear cell carcinoma

Human renal clear cell carcinoma (RCCC) accounts for up to 2% of human canc ers. To find out if thyroid hormone (T3) and its receptors (TRs) play a rol e in tumorigenesis of RCCC, the expression of TRs was evaluated on mRNA and protein level. It was found that TR alpha (both alpha1 and alpha2) mRNA am ount was significantly decreased in tumors while compared with healthy kidn ey tissue, and this decrease was deepest in G1 (well differentiated) RCCCs. In contrast, TR alpha1 protein was 1.6 x overexpressed in tumors. TR beta1 mRNA amount was overexpressed in 30% and significantly decreased in 70% of examined tumors. On the protein level, TR beta1 amount was 1.7 x lower in tumors than in healthy controls. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.