Ultrasound activates ataxia telangiectasia mutated- and Rad-3 related (ATR)-checkpoint kinase 1 (Chk1) pathway in human leukemia Jurkat cells
Ultrasound activates ataxia telangiectasia mutated- and Rad-3 related (ATR)-checkpoint kinase 1 (Chk1) pathway in human leukemia Jurkat cells
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超声激活人白血病 Jurkat 细胞中共济失调毛细血管扩张突变和 Rad-3 相关 (ATR) 检查点激酶 1 (Chk1) 通路
DOI：
10.1016/j.ultsonch.2012.04.003
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发表时间：
2012
影响因子：
8.4
通讯作者：
and Kondo T
中科院分区：
文献类型：
--
作者：
Furusawa Y;Iizumi T;Fujiwara Y;Hassan MA;Tabuchi Y;Nomura T;and Kondo T
低强度超声（US）已被证明可诱导癌细胞死亡;然而，其潜在机制仍不清楚。在这里，我们提供了新的证据，通过选择性抑制剂或小干扰RNA（siRNA）抑制检查点激酶1（Chk 1）增强了US诱导的Jurkat细胞凋亡。Jurkat细胞在任何施加强度的US后立即显示不显著的溶解，而在0.4W/cm 2的US后30分钟，约70%的细胞为γ H2 AX阳性。关于DNA损伤反应（DDR），Chk 1，已知为共济失调毛细血管扩张症突变（ATM）和rad 3相关（ATR）的靶标，在US暴露后在细胞中被磷酸化。ATM抑制剂对Chk 1磷酸化几乎没有影响，而显示ATR抑制作用的化学物质显着消除了磷酸化，表明Chk 1磷酸化在暴露于US的细胞中优先依赖于ATR而不是ATM。Chk 1的药理学抑制促进了caspase-3的切割，并增加了超声暴露后SubG 1细胞的百分比。针对Chk 1的siRNA消除了约55%的Chk 1表达，并且还促进了细胞凋亡，这表明Chk 1响应于US而发挥抗细胞凋亡作用。这些发现首次揭示了超声依赖于ATR激活Chk 1，并且激活的Chk 1参与了暴露于超声的细胞的凋亡。此外，我们认为Chk 1可能是超声辅助治疗的一个有前途的靶点。
Low-intensity ultrasound (US) has been shown to induce death of cancer cells; however, the underlying mechanism remains unclarified. Here, we provide novel evidence that the inhibition of checkpoint kinase 1 (Chk1) by a selective inhibitor or small interfering RNA (siRNA) enhances US-induced apoptosis in Jurkat cells. Jurkat cells showed insignificant lysis immediately after US at any applied intensity, whereas approximately 70% of the cells were γH2AX-positive 30min after US at 0.4W/cm2. Regarding DNA damage response (DDR), Chk1, known as a target of ataxia telangiectasia mutated (ATM) and rad3-related (ATR), was phosphorylated in cells after US exposure. An ATM inhibitor showed nearly no effect on Chk1 phosphorylation, whereas chemicals showing the ATR inhibitory effect markedly abrogated the phosphorylation, indicating that Chk1 phosphorylation is preferentially more dependent on ATR than on ATM in cells exposed to US. The pharmacological inhibition of Chk1 promoted caspase-3 cleavage and increased the percentage of cells in SubG1 after US exposure. siRNA targeting Chk1 abrogated approximately 55% of Chk1 expression and also promoted apoptosis, suggesting that Chk1 plays anti-apoptotic roles in response to US. These findings revealed, for the first time, that US activates Chk1 dependently on ATR and the activated Chk1 is involved in apoptosis of cells exposed to US. Moreover, we propose that Chk1 may be a promising target in US-aided therapy.