title: Moloney murine leukemia virus-induced tumors: recombinant proviruses in active chromatin regions.
abstract: The DNase I sensitivity of chromosomal DNA regions carrying integrated proviral genomes of Moloney (M-MuLV) and AKR Murine Leukemia Virus (AKR-MuLV), and the cellular homologue of the mos-gene (c-mos) of Moloney Sarcoma Virus (MSV) were studied in tumor tissues of leukemic mice. The genetically transmitted sequences of M-MuLV, AKR-MuLV, and the c-mos gene are all in DNase I resistant chromatin conformations in M-MuLV-induced tumors. Each M-MuLV-induced tumor contained at least one somatically acquired integrated recombinant MuLV genome that displayed two main characteristic features of active chromatin: a) a configuration hypersensitive to DNase I, and b) extensive hypomethylation. DNase I hypersensitive sites were mapped at the junction of cellular sequences and the 5'-viral large terminal repeat (LTR). Expression of a recombinant MuLV seems therefore to be a necessary feature to maintain the transformed state.
mesh_terms: D000406:AKR murine leukemia virus / Q000235:genetics; D000818:Animals; D002460:Cell Line; D002467:Cell Nucleus / Q000502:physiology; D002471:Cell Transformation, Neoplastic; D002843:Chromatin / Q000502:physiology*; D004262:DNA Restriction Enzymes; D004274:DNA, Recombinant / Q000032:analysis*; D003850:Deoxyribonuclease I; D003851:Deoxyribonucleases; D004720:Endonucleases; D007942:Leukemia, Experimental / Q000382:microbiology*; D008745:Methylation; D051379:Mice; D008807:Mice, Inbred BALB C; D008979:Moloney murine leukemia virus / Q000235:genetics*
chemical_list: D002843:Chromatin; D004274:DNA, Recombinant; D003851:Deoxyribonucleases; D004720:Endonucleases; D004262:DNA Restriction Enzymes; D003850:Deoxyribonuclease I