Expression of HLA class-I antigens on renal cell carcinoma and non-transformed renal tissue

To determine the HLA class-I antigen expression in renal cell carcinoma, the expression of beta-2-microglobulin (beta 2-m) was analyzed. 20 renal tumor specimens and 20 normal renal tissues were examined for beta 2-m expression by immunofluorescence. Homogenous staining of all normal renal tissues was observed, as expected. From the panel of 20 tumors, 17 also had a strong expression of beta 2-m. Furthermore, two newly established renal cancer cell lines exhibited a normal distribution of beta 2-m at two different passages. From these results we conclude that in most cases malignant transformation in renal cancer is not associated with a loss of HLA class-I antigens. This could be a favorable explanation for the restricted results of interferon-gamma in renal cell carcinoma, the main function of which is probably to enhance major histocompatibility complex class-I expression.