Dl. Dillehay et al., DIETARY SPHINGOMYELIN INHIBITS 1,2-DIMETHYLHYDRAZINE-INDUCED COLON-CANCER IN CF1 MICE, The Journal of nutrition, 124(5), 1994, pp. 615-620
Sphingolipids are in all eukaryotic cells and modulate cell growth, di
fferentiation, and transformation; however, little is known about the
physiological effects of their consumption. Mice were fed diets supple
mented with milk sphingomyelin to determine effects on colon carcinoge
nesis. Cancer was initiated in CF1 mice by 1,2-dimethylhydrazine. Mice
were then fed AIN76A diets supplemented with 0.025 to 0.1 g sphingomy
elin/100 g for 28 wk until the supply of sphingomyelin was depleted an
d then fed unsupplemented diet for 24 wk. Sphingomyelin did not affect
weight gain. Mice fed sphingomyelin had a 20% incidence of colon tumo
rs compared with 47% in controls (P = 0.08 for all sphingomyelin-fed m
ice vs. controls). Tumors were adenomas or adenocarcinomas and located
in the distal third of the colon. In shorter-term studies, colonic ep
ithelial cell proliferation was significantly greater than controls in
mice fed 0.025 g sphingomyelin/100 g diet, but not in those fed highe
r amounts of sphingomyelin. The number of aberrant crypts was signific
antly lower in 1,2-dimethylhydrazine-treated mice fed 0.05 g sphingomy
elin/100 g diet than in controls. These results demonstrate that consu
mption of sphingomyelin affects the behavior of colonic cells. Because
sphingolipids are present in food, the reduction in 1,2-dimethylhydra
zine-induced premalignant lesions and the incidence of colon tumors in
CF1 mice implies that these compounds may be another important class
of nutritional modulators of carcinogenesis.