title: Dietary sphingomyelin inhibits colonic tumorigenesis with an up-regulation of alkaline sphingomyelinase expression in ICR mice.
abstract: BACKGROUND
  Sphingomyelin (SM) hydrolysis generates biologically active products regulating cell growth, differentiation and apoptosis. Dietary SM has been found to inhibit colonic tumorigenesis. Alkaline sphingomyelinase (alk-SMase) is the key enzyme responsible for sphingomyelin digestion in the gut. Whether or not dietary sphingomyelin affects alk-SMase expression was examined in a colon cancer animal model.
  
  
  METHODS
  Imprinting control region (ICR) mice were injected with 1,2-dimethylhydrazine (DMH) and then fed a diet with or without SM (0.5 g/kg in diet) for 22 weeks. The colonic tumorigenesis and alk-SMase activity were determined and alk-SMase expression was examined by Western blot and PCR.
  
  
  RESULTS
  Dietary SM inhibited the tumorigenesis and increased the alk-SMase activity in the colon by 65%. The increased activity was associated with increased enzyme protein and mRNA expression. No changes of acid and neutral sphingomyelinase activities were found.
  
  
  CONCLUSIONS
  Long-term supplementation with dietary sphingomyelin up-regulates colonic alk-SMase expression, which may contribute to the inhibitory effects of sphingomyelin against colonic carcinogenesis.
authors.affiliation: Department of Hygienic Toxicology, Public Health College, Harbin Medical University, 150081 Harbin, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Zhang
authors.forename: Baixiang
authors.initials: B
authors.lastname: Li
authors.forename: Shuying
authors.initials: S
authors.lastname: Gao
authors.forename: Rui-Dong
authors.initials: RD
authors.lastname: Duan
mesh_terms: D019813:1,2-Dimethylhydrazine; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002273:Carcinogens; D002471:Cell Transformation, Neoplastic / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D003106:Colon / Q000187:drug effects / Q000201:enzymology; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000201:enzymology / Q000235:genetics / Q000517:prevention & control*; D019587:Dietary Supplements; D005260:Female; D006863:Hydrogen-Ion Concentration; D007413:Intestinal Mucosa / Q000187:drug effects / Q000201:enzymology; D051379:Mice; D008813:Mice, Inbred ICR; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011897:Random Allocation; D013108:Sphingomyelin Phosphodiesterase / Q000096:biosynthesis* / Q000235:genetics; D013109:Sphingomyelins / Q000008:administration & dosage*; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D002273:Carcinogens; D012333:RNA, Messenger; D013109:Sphingomyelins; D013108:Sphingomyelin Phosphodiesterase; D019813:1,2-Dimethylhydrazine