Inhibitory effect of arginine restriction on hepatoma growth

The potential effects of arginine depletion on promotion of hepatocarcinogenesis and the proliferation of hepatoma cells was investigated. A promotional effect of an arginine-free diet on tumor incidence in liver and kidney was not detected in rats and mice treated with N-nitrosodimethylamine. Inhibitory effects of an arginine-deficient diet on the growth of transplanted hepatomas were observed. Relative to the effect on body weight, the inhibition was greater in mice than rats. The inhibitory effects of an arginine-deficient diet were not correlated with the arginase activity in the tumors. Studies with hepatoma cells treated with polyethyleneglycol-modified arginase indicated that the inhibitory effects of arginine-deprivation on DNA synthesis need not be related to depletion of polyamine precursors.