title: Different manner of DNA synthesis in polyploidizations of meth-A and B16F10 cell lines.
abstract: Polyploidization of Meth-A and B16-F10 cells by demecolcine was examined using flow cytometry (FCM). In the presence of demecolcine, both cell lines were polyploidized to more than 16c DNA content. A marked difference was observed in the durations of S phase of polyploidy. The S-phase duration of Meth-A cells was doubly increased with ploidy, but that of B16F10 cells remained constant. When the rate of DNA synthesis in the polyploidizing cells was examined through the BrdU-uptake experiments, it was confirmed that the level of DNA-synthesis rate was constant in Meth-A cells but increased in B16F10 cells. The cellular content of c-Myc protein in polyploidized cells was also examined using anti-c-Myc monoclonal antibody. The c-Myc level of Meth-A cells was constant regardless of the ploidy but that of B16F10 cells increased with ploidy. Thus, the c-Myc content seems to be related to the duration of S phase in polyploidy.
authors.affiliation: Division of Basic Science, Research Institute of Medical Science, Ishikawa, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Fujikawa-Yamamoto
authors.forename: Z
authors.initials: Z
authors.lastname: Zong
authors.forename: M
authors.initials: M
authors.lastname: Murakami
authors.forename: S
authors.initials: S
authors.lastname: Odashima
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine; D002453:Cell Cycle / Q000235:genetics; D004247:DNA / Q000096:biosynthesis*; D003703:Demecolcine / Q000494:pharmacology; D005434:Flow Cytometry; D019084:Fluorescent Antibody Technique, Indirect; D051379:Mice; D011123:Polyploidy; D016271:Proto-Oncogene Proteins c-myc / Q000032:analysis; D016196:S Phase / Q000235:genetics; D014407:Tumor Cells, Cultured
chemical_list: D016271:Proto-Oncogene Proteins c-myc; D004247:DNA; D001973:Bromodeoxyuridine; D003703:Demecolcine