KIAA1018/FAN1 nuclease protects cells against genomic instability induced by interstrand cross-linking agents
KIAA1018/FAN1 nuclease protects cells against genomic instability induced by interstrand cross-linking agents
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DOI：
10.1073/pnas.1011081107
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发表时间：
2010-12-14
影响因子：
11.1
通讯作者：
Jiricny, Josef
中科院分区：
文献类型：
--
作者：
Yoshikiyo, Kazunori;Kratz, Katja;Jiricny, Josef
Fanconi贫血(FA)是一种罕见的遗传性疾病，以先天性缺陷、骨髓衰竭、染色体不稳定和癌症易感性为特征。FA患者细胞的一个特点是对链间交联剂，如化疗药物顺铂和丝裂霉素C(MMC)高度敏感。我们最近鉴定了一种FANCD2/FANCI相关核酸酶KIAA1018/FAN1，它的耗尽使人细胞对这些药物敏感。然而，由于FAN1在人类细胞中的下调是由siRNA介导的，因此只是暂时的，我们无法研究FAN1缺失对染色体稳定性的长期影响。我们现在描述了鸡DT40B细胞的产生，在该细胞中，FAN1基因被基因打靶打乱。FAN1缺失细胞对顺铂和丝裂霉素高度敏感，但对电离辐射、紫外线辐射、甲磺酸甲酯或喜树碱不敏感。这些细胞没有表现出姐妹染色单体交换频率的升高，无论是零星的还是MMC诱导的。有趣的是，MMC治疗引起的染色体不稳定，在数量上，但不是定性上，与FA细胞中看到的相似。这一发现，再加上证据表明，与只缺乏FAN1的细胞相比，同时缺乏FAN1和FANCC或FAN1和FANCJ的DT40细胞对顺铂的敏感性更高，这表明，尽管与FANCD2/FANCI相关，DT40细胞中的FAN1也参与了链间交联剂诱导的损伤的处理，也不依赖经典的FA途径。
Fanconi anemia (FA) is a rare genetic disease characterized by congenital defects, bone marrow failure, chromosomal instability, and cancer susceptibility. One hallmark of cells from FA patients is hypersensitivity to interstrand cross-linking agents, such as the chemotherapeutics cisplatin and mitomycin C (MMC). We have recently characterized a FANCD2/FANCI-associated nuclease, KIAA1018/FAN1, the depletion of which sensitizes human cells to these agents. However, as the down-regulation of FAN1 in human cells was mediated by siRNA and thus only transient, we were unable to study the long-term effects of FAN1 loss on chromosomal stability. We now describe the generation of chicken DT40 B cells, in which the FAN1 locus was disrupted by gene targeting. FAN1-null cells are highly sensitive to cisplatin and MMC, but not to ionizing or UV radiation, methyl methanesulfonate, or camptothecin. The cells do not display elevated sister chromatid exchange frequencies, either sporadic or MMC-induced. Interestingly, MMC treatment causes chromosomal instability that is quantitatively, but not qualitatively, comparable to that seen in FA cells. This finding, coupled with evidence showing that DT40 cells deficient in both FAN1 and FANCC, or FAN1 and FANCJ, exhibited increased sensitivity to cisplatin compared with cells lacking only FAN1, suggests that, despite its association with FANCD2/FANCI, FAN1 in DT40 cells participates in the processing of damage induced by interstrand cross-linking-generating agents also independently of the classical FA pathway.