title: Methylation status of c-myc oncogene in leukemic cells: hypomethylation in acute leukemia derived from myelodysplastic syndromes.
abstract: DNA methylation plays an important role in gene regulation. We have analyzed the methylation status of CCGG sites in and around the human proto-oncogene c-myc in blood cells from patients with acute and chronic leukemias and with myelodysplastic syndromes using restriction endonucleases. The 5' region of c-myc was unequivocally hypomethylated in all the 58 specimens studied, including 10 from normal bone marrow and 1 from human placenta. In contrast, the 3' region was hypermethylated in a great majority of cases. However, this region was hypomethylated in 1 of 12 patients with de novo acute myeloid leukemia, 1 of 6 patients with chronic myeloid leukemia, and 4 of 5 patients with acute myeloid leukemia preceded by a documented stage of myelodysplastic syndromes. One possible mechanism for the 3' region of c-myc to have remained hypomethylated may be a "delayed methylation" during transforming events toward a more aggressive stage of the disease, but the precise mechanism is unknown.
authors: Third Department of Internal Medicine, Gunma University School of Medicine, Japan.
authors: N
authors: N
authors: Tsukamoto
authors: K
authors: K
authors: Morita
authors: M
authors: M
authors: Karasawa
authors: M
authors: M
authors: Omine
mesh_terms: D000208:Acute Disease; D001483:Base Sequence; D015139:Blotting, Southern; D004273:DNA, Neoplasm / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D016259:Genes, myc / Q000235:genetics*; D006801:Humans; D007951:Leukemia, Myeloid / Q000209:etiology / Q000235:genetics* / Q000378:metabolism; D008745:Methylation; D009190:Myelodysplastic Syndromes / Q000150:complications / Q000235:genetics* / Q000378:metabolism; D000090063:Proto-Oncogene Mas; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism
chemical_list: D004273:DNA, Neoplasm; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D016271:Proto-Oncogene Proteins c-myc