Tumor in Nude Mice

Erythropoietin was measured by exhypoxic polycythemic mouse method in the course of a 64-yr-old male with renal cell carcinoma associated with erythrocytosis. Serum erythropoietin fluctuated with progression of the disease. Preoperative elevated erythropoietin (0.1 1 U/mI. p < 0.05) subsided after nephrectomy and again increased with developing lung metastasis (0.1 U/mI, p < 0.02). Erythropoletin was markedly increased in the tumorous extracts from primary renal cell carcinoma in the kidney (0.2 U/g. p < 0.01) and lung metastasis (0.8 U/g. p < 0.01). Renal cell carcinoma from the lung metastasis was transplanted into nude mice. resulting in erythrocytosis in some of these mice. In the erythrocytotic mice, erythropoietin was elevated to levels of 0.25-0.9 U/g (p < 0.01 ) in the tumorous extracts and increased (0.67 U/mI, p < 0.02) in the serum. These results indicate that this renal cell carcinoma is an erythropoietinproducing tumor. and this tumor has been successfully transplanted in nude mice for the first time.