title: Disruption of the ARF transcriptional activator DMP1 facilitates cell immortalization, Ras transformation, and tumorigenesis.
abstract: The DMP1 transcription factor induces the ARF tumor suppressor gene in mouse fibroblasts, leading to cell cycle arrest in a p53-dependent manner. We disrupted sequences encoding the DNA-binding domain of DMP1 in mouse embryonic stem cells and derived animals lacking the functional protein. DMP1-null animals are small at birth, and males develop more slowly than their wild-type littermates. Some adult animals exhibit seizures and/or obstuctive uropathy, each of unknown cause. The growth of explanted DMP1-null mouse embryo fibroblasts (MEFs) is progressively retarded as cells are passaged in culture on defined transfer protocols; but, unlike the behavior of normal cells, p19(ARF), Mdm2, and p53 levels remain relatively low and DMP1-null MEFs do not senesce. Whereas the establishment of cell lines from MEFs is usually always accompanied by either p53 or ARF loss of function, continuously passaged DMP1-null cells readily give rise to established 3T3 and 3T9 cell lines that retain wild-type ARF and functional p53 genes. Early-passage DMP1-null cells, like MEFs from either ARF-null or p53-null mice, can be morphologically transformed by oncogenic Ha-Ras (Val-12) alone. Splenic lymphocytes harvested from both DMP1-null and ARF-null mice exhibit enhanced proliferative responses in long-term cultures when stimulated to divide with antibody to CD3 and interleukin-2. Although only 1 of 40 DMP1-null animals spontaneously developed a tumor in the first year of life, neonatal treatment with dimethylbenzanthracene or ionizing radiation induced tumors of various histologic types that were not observed in similarly treated DMP1(+/+) animals. Karyotypic analyses of MEFs and lymphomas from DMP1-null animals revealed pseudodiploid chromosome numbers, consistent with the retention of wild-type p53. Together, these data suggest that ARF function is compromised, but not eliminated, in animals lacking functional DMP1.
authors.affiliation: Department of Tumor Cell Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA.
authors.forename: K
authors.initials: K
authors.lastname: Inoue
authors.forename: R
authors.initials: R
authors.lastname: Wen
authors.forename: J E
authors.initials: JE
authors.lastname: Rehg
authors.forename: M
authors.initials: M
authors.lastname: Adachi
authors.forename: J L
authors.initials: JL
authors.lastname: Cleveland
authors.forename: M F
authors.initials: MF
authors.lastname: Roussel
authors.forename: C J
authors.initials: CJ
authors.lastname: Sherr
mesh_terms: D016475:3T3 Cells; D000367:Age Factors; D000818:Animals; D002455:Cell Division; D002478:Cells, Cultured; D018076:DNA, Complementary / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D015723:Gene Library; D005838:Genotype; D006579:Heterozygote; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008957:Models, Genetic; D016297:Mutagenesis, Site-Directed; D009374:Neoplasms, Experimental / Q000139:chemically induced / Q000235:genetics; D010641:Phenotype; D011506:Proteins / Q000378:metabolism*; D013601:T-Lymphocytes / Q000166:cytology; D013997:Time Factors; D014018:Tissue Distribution; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology; D014170:Transformation, Genetic; D025803:Tumor Suppressor Protein p14ARF; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D018631:ras Proteins / Q000378:metabolism*
chemical_list: C491126:DMTF1 protein, human; D018076:DNA, Complementary; C102116:Dmtf1 protein, mouse; D007376:Interleukin-2; D011506:Proteins; D014157:Transcription Factors; D025803:Tumor Suppressor Protein p14ARF; D016159:Tumor Suppressor Protein p53; D018631:ras Proteins