title: Establishment and characterization of a SV40 T-antigen immortalized epithelial-like cell line derived from the newborn rat colorectum and its malignant transformation by the ras oncogene.
abstract: Epithelial-like cells from the colorectum of one-day-old newborn rats were immortalized by transfection with the simian virus 40 (SV40) T-antigen gene, and a cell line OUMS-25 was established. The cells were positive for the SV40 T-antigen, and immunoreactive to a colonic epithelial cell monoclonal antibody and a keratin-18 monoclonal antibody. Ultrastructural studies revealed the presence of microvilli on the cell surface and desmosomes between the adjacent cells. Karyotypic analysis showed that OUMS-25 cells were aneuploid. Cloning efficiency of the cells was 0.01% in soft agar. However, the cells were not tumorigenic in the syngeneic newborn rats. The cells were further transformed by transfection with the cloned activated c-Ha-ras oncogene containing a point mutation within codon 61. Characteristics of the activated-c-Ha-ras transfected cells (OUMS-25/RAS) were different in some respects from those of the parent cells (OUMS-25). OUMS-25/RAS cells demonstrated more malignant morphology, elevated cloning efficiency in soft agar, and tumorigenicity. This is the first report on the immortalization and malignant transformation of colorectal epithelial-like cells by transfection with a combination of SV40 T-antigen gene and cloned activated c-Ha-ras oncogene.
authors.affiliation: Department of Cell Biology, Okayama University Medical School, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Seshimo
authors.forename: M
authors.initials: M
authors.lastname: Miyazaki
authors.forename: M
authors.initials: M
authors.lastname: Mori
authors.forename: K
authors.initials: K
authors.lastname: Orita
authors.forename: M
authors.initials: M
authors.lastname: Namba
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000952:Antigens, Polyomavirus Transforming / Q000235:genetics*; D001483:Base Sequence; D002461:Cell Line, Transformed; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D003106:Colon / Q000166:cytology* / Q000648:ultrastructure; D015179:Colorectal Neoplasms / Q000235:genetics; D011905:Genes, ras / Q000235:genetics*; D007413:Intestinal Mucosa / Q000166:cytology; D008969:Molecular Sequence Data; D051381:Rats; D012007:Rectum / Q000166:cytology* / Q000648:ultrastructure; D014162:Transfection
chemical_list: D000952:Antigens, Polyomavirus Transforming