Gene expression of erythropoietin in renal cell carcinoma

A 57-year-old man with renal cell carcinoma and erythrocytosis showed a hig h serum level of erythropoietin (EPO). High EPO signal was observed on Nort hern blot analysis and RT-PCR in the total RNA extracted from the renal tum or. Immunohistochemical staining also demonstrated tumor tissue with high i mmunostaining of EPO, Nucleotide sequences of EPO cDNA in the tumor were no rmal. To date, only one report has discussed the nucleotide sequences of a tumor's EPO gene; it showed mutant EPO cDNA in hepatocellular carcinoma tis sue. This is the first demonstration of normal EPO cDNA in renal cell carci noma.