title: Alterations of mouse proto-oncogenes in sarcomas induced after transplantation of human tumors in athymic nude mice.
abstract: During serial subcutaneous transplantation of several types of human tumors into nude mice, the local development of malignant mouse-specific sarcomas has been observed. Although the frequency of sarcoma induction is low, this phenomenon is very important because the mouse-specific sarcomas completely replaced the human tumors during serial transplantation. The DNA of five independently induced mouse-specific sarcomas was transfected into NIH/3T3 cells in order to detect oncogenes associated with mouse-specific sarcoma induction. Two of these DNAs were found to carry activated mouse c-N-ras and c-Ki-ras genes. The sequence analysis of the molecularly cloned mouse c-N-ras oncogene showed a single nucleotide transition from G to A at the 12th codon. This results in substitution of aspartic acid for glycine at this position. The mouse c-myc gene was also found to be amplified in a sarcoma. In these mouse sarcoma DNAs, human Alu sequences were not detected. These data strongly suggest that the mouse-specific sarcomas were not induced by the transfer of human transforming sequences but by the alterations of mouse proto-oncogenes.
authors.affiliation: Department of Hygiene and Oncology, Tokyo Medical and Dental University School of Medicine.
authors.forename: Y
authors.initials: Y
authors.lastname: Yuasa
authors.forename: H
authors.initials: H
authors.lastname: Yamazaki
authors.forename: K
authors.initials: K
authors.lastname: Maruo
authors.forename: Y
authors.initials: Y
authors.lastname: Ueyama
authors.forename: M
authors.initials: M
authors.lastname: Shibuya
authors.forename: N
authors.initials: N
authors.lastname: Tamaoki
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D003001:Cloning, Molecular; D004273:DNA, Neoplasm / Q000235:genetics; D005354:Fibrosarcoma / Q000235:genetics; D005784:Gene Amplification; D011905:Genes, ras / Q000235:genetics; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009368:Neoplasm Transplantation; D011519:Proto-Oncogenes / Q000235:genetics*; D015183:Restriction Mapping; D012513:Sarcoma, Experimental / Q000235:genetics*; D014162:Transfection
chemical_list: D004273:DNA, Neoplasm