Induction of DNA Damage and G2 Cell Cycle Arrest by Diepoxybutane through the Activation of the Chk1-Dependent Pathway in Mouse Germ Cells
Induction of DNA Damage and G2 Cell Cycle Arrest by Diepoxybutane through the Activation of the Chk1-Dependent Pathway in Mouse Germ Cells
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DOI：
10.1021/tx500489r
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发表时间：
2015-03-01
影响因子：
4.1
通讯作者：
Ao, Lin
中科院分区：
文献类型：
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作者：
Dong, Jianyun;Wang, Zhi;Ao, Lin
1，2：3，4-二环氧丁烷（DEB）是1，3-丁二烯（BD）的主要致癌代谢产物，其潜在的遗传毒性可导致细胞DNA链断裂。DEB对雄性生殖细胞DNA损伤的不良影响尚未得到深入研究，相关机制尚未阐明：使用小鼠精母细胞衍生的GC-2细胞，我们在本研究中证明，DEB引起增殖抑制和细胞周期阻滞在G2期，但没有凋亡。DEB也可诱导DNA损伤，如γ-H2 AX表达、彗星试验和微核试验所证明。同时，DEB还激活了Chk 1/Cdc 25 c/Cdc 2信号通路，UCN-01或Chk 1 siRNA可阻断该通路。DEB -1处理的GC_2细胞产生活性氧，N-乙酰-L-半胱氨酸预处理可部分减轻DEB-1诱导的DNA损伤，并使G_2期阻滞。此外，睾丸细胞的测量显示，在给予DEB的小鼠中，四倍体细胞的比例增加，同时p-Chk 1的表达增强。此外，还观察到精子活动力降低、消耗性畸形增加和睾丸组织学异常等生殖缺陷表型。总之，这些结果表明，DEB诱导DNA损伤和G（2）细胞周期阻滞通过激活Chk 1-clependent途径，而氧化应激可能与引发雄性生殖细胞的毒性。
1,2:3,4-Diepoxybutane (DEB) is a major carcinogenic metabolite of 1,3-butadiene (BD), 'which has been shown to cause DNA strand breaks in cells through its potential genotoxicity. The adverse effect of DEB on male reproductive cells in response to DNA damage has not been thoroughly studied, and the related mechanism is yet to be elucidated: Using mouse spermatocyte-derived GC-2 cells, we demonstrated in the present study that DEB caused the proliferation inhibition and matked cell cycle arrest at the G2 phase but not apoptosis. DEB alSO induced DNA damage as evidenced by gamma-H2AX expression, the comet assay, and the cytokinesis-block micronucleus assay. Meanwhile; DEB triggeted the Chk1/Cdc25c/Cdc2 signal pathway, which could be abated in the presenCe of UCN-01 or Chk1 siRNA. GC,2 cells exposed to DEB -experienced ROS generation and pretreatrnent of N-acetyl-L-cysteine, partly attenuated DEB-induced DNA damage, and G(2) arrest. Furthermore, measurement of testicular cells showed an increased proportion of tetraploid cells in mice administrated with DEB, alongside the enhanced expression of p-Chk1. Also, the defective reproductive phenotypes, including reduced sperm motility, increased spent Malformation, and histological abnormality of testes, Were observed. In conclusion, these results suggest DEB induces DNA damage and G(2) cell cycle arrest by activating the Chk1-clependent pathway, while oxidative stress may be associated with eliciting toxicity in male reproductive cells.