Taylor A M, Laher H B, Morgan G R
Carcinogenesis. 1985 Jun;6(6):945-7. doi: 10.1093/carcin/6.6.945.
Streptonigrin is an antitumour antibiotic, which at low doses produces DNA strand breaks in cultured cells leading, e.g., to decreased colony-forming ability and decreased rates of DNA synthesis. At higher doses the drug can induce unscheduled DNA synthesis (UDS) presumably as a consequence of excision of large DNA adducts. Ataxia telangiectasia (A-T) cells are unusually sensitive to streptonigrin, but we show here that they can perform excision repair, as demonstrated by UDS, at the same level as normal cells following exposure to the drug. This result suggests that of the apparent two modes of action of streptonigrin it is the DNA strand-breaking capacity to which A-T cells are unusually sensitive. This is consistent with previous reports suggesting some form of DNA strand break in A-T cells is deficiently repaired.
链黑菌素是一种抗肿瘤抗生素，低剂量时可在培养细胞中产生DNA链断裂，例如导致集落形成能力下降和DNA合成速率降低。高剂量时，该药物可诱导DNA修复合成（UDS），这可能是切除大的DNA加合物的结果。共济失调毛细血管扩张症（A-T）细胞对链黑菌素异常敏感，但我们在此表明，它们能够进行切除修复，如UDS所示，在接触该药物后与正常细胞处于相同水平。这一结果表明，在链黑菌素明显的两种作用模式中，A-T细胞对其DNA链断裂能力异常敏感。这与之前的报道一致，即A-T细胞中某种形式的DNA链断裂修复不足。
