Niwa O, Sugahara T
J Natl Cancer Inst. 1979 Feb;62(2):329-35.
Cell lines from AKR and BALB/c mouse embryos were compared for their sensitivity to X-ray induction of endogenous type C virus. K-Balb cells, a Balb/3T3 cell line nonproductively transformed by Kirsten murine sarcoma virus, were found to be sensitive to X-irradiation. At a dose as low as 50 R, X-rays induced virus expression in K-Balb cells, and the induction frequency increased with increasing dose of X-rays up to 400 R. Among two classes of inducible endogenous viruses carried by K-Balb cells, only Balb:virus-2 was activated by X-irradiation, whereas both Balb:virus-1 and Balb:virus-2 were activated after the cells were treated with 5-iodo-2'-deoxyuridine. UV light and 4-nitroquinoline 1-oxide were also shown to induce virus expression in K-Balb cells. The virus-induction frequency for these physical and chemical carcinogens was much lower (approximately 3 times 10(-4)) than that for 5-bromo-2'-deoxyuridine (approximately 1 times 10(-1)).
比较了来自AKR和BALB/c小鼠胚胎的细胞系对X射线诱导内源性C型病毒的敏感性。发现K-Balb细胞，一种由 Kirsten 小鼠肉瘤病毒非生产性转化的Balb/3T3细胞系，对X射线照射敏感。在低至50 R的剂量下，X射线诱导K-Balb细胞中的病毒表达，并且诱导频率随着X射线剂量增加至400 R而增加。在K-Balb细胞携带的两类可诱导内源性病毒中，只有Balb:virus-2被X射线激活，而在用5-碘-2'-脱氧尿苷处理细胞后，Balb:virus-1和Balb:virus-2均被激活。紫外线和4-硝基喹啉1-氧化物也显示可诱导K-Balb细胞中的病毒表达。这些物理和化学致癌物的病毒诱导频率比5-溴-2'-脱氧尿苷的诱导频率低得多（约3×10⁻⁴）（约1×10⁻¹）。
