Influence of inorganic and organic iron compounds on parameters of cell growth and survival in human colon cells.
Increased risk for development of colon cancer is associated with red meat intake and iron toxicity is discussed for one underlying mechanism. Anyhow, for iron itself only limited evidence is found. In this study, effects of different iron compounds on proliferation of HT29 carcinoma and LT97 adenoma human colon cells were investigated. After treatment of cells with inorganic (ferrous sulfate: FeSO4 and ferric nitrilotriacetate: FeNTA) and organic (hemoglobin and hemin) iron sources (24-72 h), number of cells and metabolic activity were measured. Under normal cell culture conditions, neither iron compound elevated cell growth in either cell line with the exception of FeNTA which induced LT97 cell growth significantly. Distinct inhibition of cell proliferation was measured for organic iron. Serum-free incubation of HT29 cells revealed growth promoting properties of iron under deficiency. Even though organic iron, especially hemin, was a potent growth factor, both substances showed also dose-dependent cytotoxic effects. In conclusion, these data emphasize that not iron itself, but merely organic iron may promote carcinogenic events. Since promotion of proliferation was only detectable under deficiency, cytotoxic properties of organic iron may be of more importance in colon carcinogenesis.
Klenow
Stefanie
S
Friedrich-Schiller-University Jena, Department of Nutritional Toxicology, Institute for Nutritional Sciences, Dornburger Str. 24, 07743 Jena, Germany. steffi.klenow@gmx.net
Pool-Zobel
Beatrice L
BL
Glei
Michael
M
D000328:Adult; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003106:Colon / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D005260:Female; D005290:Ferric Compounds / Q000633:toxicity; D005296:Ferrous Compounds / Q000633:toxicity; D019073:HT29 Cells; D006427:Hemin / Q000633:toxicity*; D006454:Hemoglobins / Q000633:toxicity*; D006801:Humans; D058085:Iron Compounds / Q000633:toxicity*; D009571:Nitrilotriacetic Acid / Q000031:analogs & derivatives / Q000633:toxicity
D005290:Ferric Compounds; D005296:Ferrous Compounds; D006454:Hemoglobins; D058085:Iron Compounds; C020748:ferrous sulfate; C024823:ferric sulfate; D006427:Hemin; D009571:Nitrilotriacetic Acid; C020326:ferric nitrilotriacetate