Effects of supplemental zinc on melanoma metastasis in mice

The influence of a single intraperitoneal injection of zinc (0.5, 1.5 and 4.5 mg/kg) on the metastasis and subsequent growth of radiolabelled melanoma cells was examined in mice receiving tumor cells s.c. or i.v. 24 h following zinc treatment. Parenteral zinc resulted in increased tumor cell survival in the liver, spleen and lungs of zinc-treated mice 1 day post-injection, while 21-day cell survival was enhanced in the spleens of s.c. injected, zinc-treated mice. Regardless of zinc exposure, relative numbers of s.c. injected tumor cells decreased with time in the lungs and spleen, while increasing in the liver and kidneys. A single dose of zinc can modify the organ distribution and viability of metastatic tumor cells in mice.