Background: Renal cell carcinomas have developed various strategies to escape immune cell recognition, including down-regulation or loss of classic HLA class I antigens (A, B, C) and aberrant expression of non-classic HLA class I antigens (G, E). In this study both classic and non-classic HLA class I antigens were tested in tumor specimens and established primary cell cultures derived from renal cell carcinoma patients.
Material/methods: HLA class I antigens were evaluated by immunohistochemical staining and the intensity of cytoplasmic staining was measured semiquantitatively. Renal tumor tissue obtained from nephrectomy was used for the explant culture. MTT assay was performed to test the chemoresistance of primary cell line cultures to common cytostatics.
Results: HLA-G and HLA-E were found in 62% and 100% of the analyzed tumor samples, respectively. Markedly higher levels of the non-classic HLA-G and -E antigens compared with the classic HLA-A, -B, and -C antigens were observed. The cells of the control renal tissues were HLA-A, -B, -C, and -E positive and HLA-G negative. Cell line cultures were successfully established in 85% of the renal cell carcinoma specimens. No or minimal changes in classic HLA-A, B, and C antigen staining were observed during cultivation of the primary cell line cultures. No correlation between HLA class I antigen expression and chemoresistance, histopathological stage, or nuclear grade was found.
Conclusions: These findings suggest that primary cell line cultures derived from surgical specimens of renal cell carcinomas are a feasible model for immunotherapy research through their high cultivation potential.