Suppression of metastasis of intratesticular inoculation of B16FO melanoma cells by a novel nutrient mixture in male athymic nude mice

Metastasis, commonly to the lung, is the major cause of mortality from testicular cancer. The aim of the present study was to examine the effect of a novel nutrient mixture (NM) containing ascorbic acid, amino acids and green tea extract on the inhibition of melanoma growth and metastasis using a model of intratesticular inoculation of B16FO cells into nude mice. Male athymic mice (n=12), 10–12 weeks of age, were inoculated with 5×10(5) B16FO melanoma cells in 100 μl of PBS into the right testis, while the left testis was left untreated. Following inoculation, the mice were randomly divided into two groups. The control group (n=6) was fed a regular mouse chow diet and the NM 1% group (n=6) the same diet, but supplemented with 1% NM. Four weeks later the mice were sacrificed and the abdominal cavity was opened. Mice in the control group exhibited extensive metastasis in the peritoneal cavity and severely enlarged right testes and necrotic seminiferous tubules. By contrast, in the NM 1% fed group there was no evidence of peritoneal metastasis in 50% of the animals and mild metastasis in the remaining 50%. The right testes were enlarged and seminiferous tubules in the area of invasion showed evidence of degeneration. No metastasis to the liver, kidney or spleen were evident in either group. However, severe lung metastasis was observed in 2 of 6 mice in the control group and mild metastasis in 2 of 6 mice in the NM 1% group. In conclusion, these results confirm earlier studies and verify the anti-metastatic potential of NM.