title: DNA methylating capacity in metastatic variants of a human melanoma cell line.
abstract: Certain highly metastatic (in athymic immunosuppressed "nude" mice) variants of the poorly metastatic human melanoma cell line MeWo have been found to contain dramatically reduced levels of DNA 5-methylcytosine compared to the parental cell line. To identify the underlying biochemical defect which could be responsible for the reduced DNA methylation within these cells, the intracellular ratio of S-adenosylmethionine/S-adenosylhomocysteine and level of extractable DNA-methyltransferase were examined. No significant difference in the ratio of S-adenosylmethionine/S-adenosylhomocysteine or extractable DNA-methyltransferase activity were found between the highly malignant variants and the parental cell line. Thus, stable alterations in these cellular parameters are not likely responsible for the reduction in DNA 5-methylcytosine content which appears to occur during "progression" of the MeWo tumor line from a relatively benign to highly malignant state.
authors.affiliation: Department of Experimental Oncology, Ottawa Regional Cancer Centre, Ontario, Canada.
authors.forename: R G
authors.initials: RG
authors.lastname: Liteplo
authors.forename: S
authors.initials: S
authors.lastname: Munro
mesh_terms: D002460:Cell Line; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000378:metabolism*; D004273:DNA, Neoplasm / Q000378:metabolism*; D014644:Genetic Variation; D006801:Humans; D008545:Melanoma / Q000378:metabolism*; D008745:Methylation; D012435:S-Adenosylhomocysteine / Q000032:analysis; D012436:S-Adenosylmethionine / Q000032:analysis
chemical_list: D004273:DNA, Neoplasm; D012436:S-Adenosylmethionine; D012435:S-Adenosylhomocysteine; D004248:DNA (Cytosine-5-)-Methyltransferases