title: Increased sensitivity of EBNA2-transformed rat fibroblasts to ionizing radiation.
abstract: To clarify whether expression of Epstein-Barr virus(EBV) nuclear antigen 2 (EBNA2) correlates with sensitivity to ionizing radiation, we tested EBNA2-transformed rat fibroblast clones for their radiosensitivity to X-rays. These transformed clones reproducibly generated tumors in mice. X-irradiation suppressed the growth of the tumors, and irradiated mice survived longer than non-irradiated ones. In contrast, tumors formed by activated H-ras or E6-E7 genes of human papillomavirus type 16 (HPV16) were strongly resistant to the same dose of X-irradiation. In in vitro culture, these EBNA2-expressing clones also showed higher radiosensitivity than cell lines transformed by activated H-ras and E6E7 genes. The averaged D(o) of EBNA2-expressing clones was 2.3 times lower than that of non-expressing and control clones. These results suggest that expression of EBNA2 is responsible for the radiosensitivity.
authors.affiliation: Clinical Research Institute, Osaka National Hospital, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Shimakage
authors.forename: Y
authors.initials: Y
authors.lastname: Miyata
authors.forename: H
authors.initials: H
authors.lastname: Inoue
authors.forename: M
authors.initials: M
authors.lastname: Yutsudo
authors.forename: A
authors.initials: A
authors.lastname: Hakura
mesh_terms: D000818:Animals; D002461:Cell Line, Transformed; D002472:Cell Transformation, Viral; D019309:Epstein-Barr Virus Nuclear Antigens / Q000235:genetics*; D005347:Fibroblasts / Q000528:radiation effects / Q000821:virology; D018014:Gene Transfer Techniques; D004854:Herpesvirus 4, Human; D006801:Humans; D051379:Mice; D051381:Rats
chemical_list: D019309:Epstein-Barr Virus Nuclear Antigens