• Medientyp: E-Artikel
  • Titel: Gamma-Ray- and UV-Sensitive Strains of a Radioresistant Cell Line: Isolation and Cross-Sensitivity to Other Agents
  • Beteiligte: Koval, Thomas M.
  • Erschienen: Academic Press, Inc., 1991
  • Erschienen in: Radiation Research, 127 (1991) 1, Seite 58-63
  • Sprache: Englisch
  • ISSN: 0033-7587; 1938-5404
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  • Beschreibung: <p>Two γ-ray-sensitive and two ultraviolet (UV)-sensitive variants were isolated from the γ-ray- and UV-resistant TN-368 lepidopteran insect cell line. The isolation was performed by inducing mutations in the TN-368 cells using ethyl methanesulfonate, growing them for an expression period, irradiating with &lt;sup&gt;137&lt;/sup&gt; Cs γ rays or 254-nm UV radiation, allowing cells to incorporate 5-bromodeoxyuridine (BrdU) in the presence of hydroxyurea (DNA repair synthesis), and finally irradiating with 365-nm UV radiation to cause DNA strand breakage at sites of BrdU incorporation with the intent of killing those cells that have undergone DNA repair synthesis and sparing those cells which, for a variety of reasons, did not. The survival of the Cs2 and Cs7 variants exposed to X rays is significantly different from the parent TN-368 line at the P &lt; 0.0001 level. The survival of the UV10 and UV19 variants exposed to UV radiation is different from the parent at the P &lt; 0.0001 and P &lt; 0.003 levels, respectively. In cross-sensitivity testing of the γ-ray-sensitive variants, only Cs2 is more sensitive to 254-nm UV and only Cs7 is more sensitive to 44°C heating; both are sensitive to PUVA. The UV-sensitive mutants are both sensitive to X irradiation, PUVA, and mitomycin C. However, UV10 is not sensitive to 44°C heating while UV19 is, making UV19 the only variant strain sensitive to all agents examined. Despite the isolation procedure which was intended to select for DNA repair-deficient cells, the results suggest that a more general mechanism is responsible for the sensitivity of the variant cells to the agents tested.</p>