title: The elevated requirement for methionine by transformed rat liver epithelial cells in vitro.
abstract: Growth constants appear to constitute a useful tool in comparing the behavior for transformed and untransformed cells in culture. The substitution of homocysteine for methionine in culture medium caused a greater depression of growth with 3/4 of the transformed epithelial and with 10/14 other cell lines tested compared to the growth depression seen in similar untransformed lines. The greater growth depression exhibited by transformed lines on methionine-deficient, homocysteine-supplemented medium could generally be attributed to: 1. Greater growth of transformed cells in complete medium, and 2. The lower levels of methyltransferase generally found in the transformed lines. Finally methyltransferase appears to be a major determinant of growth of both normal an transformed cells growing in a methionine-deficient, homocysteine-supplemented medium.
mesh_terms: D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase / Q000378:metabolism; D000818:Animals; D002455:Cell Division; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D003470:Culture Media; D006710:Homocysteine; D007700:Kinetics; D008099:Liver / Q000166:cytology*; D008715:Methionine / Q000494:pharmacology*; D051381:Rats
chemical_list: D003470:Culture Media; D006710:Homocysteine; D008715:Methionine; D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase