title: Up-regulation of cell cycle-associated genes by p53 in apoptosis of an erythroleukemic cell line.
abstract: A murine erythroleukemic cell line (1-2-3) which expresses only the temperature-sensitive mutant p53 gene (Ala-to-Val substitution at codon 135) was established. When these cells were cultured at 32 degrees C, the growth rate was reduced significantly and DNA fragmentation, a typical character of apoptosis, was observed. In this process, p53 migrated from cytoplasm to nucleus and protein complexes binding to the p53-responsive element were detected in nuclear extracts of the cells cultured at 32 degrees C by gel-shift assay and transactivation from the p53-responsive element was detected. The expression of the p21 (waf1/cip1/sdi1), cyclin G and gadd45 genes was increased (about 3 to 4 fold that at 37 degrees C), when the cells were cultured at 32 degrees C. However, the expression of the bax gene was increased slightly (about 1.5 fold that at 37 degrees C) and no significant change was detected in expression of the mdm2 gene. No change in the amount of Fas antigen was observed by flow cytometric analysis. Transcripts of the bcl-2 and fasl gene were not detected in the cells both at 37 degrees C and 32 degrees C. These results suggest that up-regulation of the genes associated with the cell cycle and/or DNA replication, such as p21, cyclinG and gadd45 rather than bax, fas, fasl and bcl-2 may be important for induction of apoptosis of this erythroleukemic cell line by p53.
authors.affiliation: Molecular Oncology Laboratory, Tsukuba Life Science Center, RIKEN, Ibaraki, Japan.
authors.forename: M V
authors.initials: MV
authors.lastname: Kato
authors.forename: H
authors.initials: H
authors.lastname: Sato
authors.forename: H
authors.initials: H
authors.lastname: Anzai
authors.forename: M
authors.initials: M
authors.lastname: Nagayoshi
authors.forename: Y
authors.initials: Y
authors.lastname: Ikawa
mesh_terms: D000818:Animals; D017209:Apoptosis; D002453:Cell Cycle; D002460:Cell Line; D056746:Cyclin G; D056766:Cyclin G1; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000096:biosynthesis; D053938:DNA Fragmentation; D004261:DNA Replication; D004791:Enzyme Inhibitors; D015972:Gene Expression Regulation, Neoplastic; D016158:Genes, p53; D047908:Intracellular Signaling Peptides and Proteins; D004915:Leukemia, Erythroblastic, Acute / Q000235:genetics* / Q000473:pathology*; D051379:Mice; D017354:Point Mutation; D014176:Protein Biosynthesis; D011506:Proteins; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis*; D000097642:GADD45 Proteins
chemical_list: D056746:Cyclin G; D056766:Cyclin G1; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D011506:Proteins; D016159:Tumor Suppressor Protein p53; D000097642:GADD45 Proteins; C534703:Ccng1 protein, mouse; C493957:Cdkn1a protein, mouse