Quantitative Analysis of Transforming Growth Factor-beta1 in Renal Cell Carcinoma

Oh, Bong Ryoul; Kim, Sung Jin; Lee, Jae Gue; Kwon, Dong Deuk; Ryu, Soo Bang; Park, Yang Il

Abstract

Purpose
The transforming growth factor-beta (TGF-beta) is a peptide that has diverse biologic actions in human tissue and is thought to contribute to tumor development and progression. Increased TGF-beta1 levels were found in several types of malignant tumors. TGF-beta1 expression in RCC and adjacent normal kidney tissues was examined to determine the TGF-beta1 in renal cell carcinoma (RCC).
MATERIALS AND METHODS
The TGF-beta1 protein levels in cancer and a normal portion of a specimen were analyzed in 61 radical nephrectomized clear cell type RCC by an enzyme-linked immunosorbent assay (ELISA), with the results compared with the clinicopathological characteristics. Immunohistochemical staining was performed to localize their expression.
RESULTS
Compared with non-tumor kidney specimens, primary renal cell carcinoma demonstrated a significantly higher TGF-beta1 protein level (p<0.001). There were significant differences in the TGF-beta1 level among the histological grade (p<0.01). The tissue TGF-beta1 level was the highest in T4 stage, but there was no statistical significance between the T stages. Immunohistochemical analysis demonstrated that TGF-beta1 was localized to the tumor cytoplasm and their intensity reflected the protein expression level in these tissues.
CONCLUSIONS
These results suggest that enhanced TGF-beta1 expression contributes to carcinogenesis and tumor progression in the later stages of renal cell carcinoma.