ONCOGENE AND HSP-70 EXPRESSION IN PRIMARY TUMOR-CELL CULTURES OF RENAL-CELL CARCINOMA COMPARED TO THEIR CORRESPONDING CELL-LINE

Background: Tumor progression in renal cell carcinoma (RCC) can be exp lained by a multistep model in which the activation of certain oncogen es such as c-neu and c-fos appear to be early events in tumorigenesis, while the expression of p53 and pan-ras are found in advanced stages. Material and Methods: The expression of oncogenes and growth factors was examined in 29 primary tumor cell cultures (PTCC) of RCC using imm unocytochemistry. Results: rn PTCC high expression of c-neu and c-fos was present in all tumors, whereas mdr, TGF-a, EGF, c-myc, pan-ras, p5 3 and HSP-70 was detected at low expression levels. In 27% (8/29) of P TCC, cell lines (CL) were established. Oncogene expression was increas ed in CL compared to PTCC. Conclusion: The pattern of oncogene express ions found in CL is similar to findings described in highly malignant tumors in vivo. Therefore, the establishment of CL seems to depend on a selective recruitment of tumor cells with an upregulated oncogene ex pression.