cAMP signaling inhibits radiation-induced ATM phosphorylation leading to the augmentation of apoptosis in human lung cancer cells.
cAMP signaling inhibits radiation-induced ATM phosphorylation leading to the augmentation of apoptosis in human lung cancer cells.
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DOI：
10.1186/1476-4598-13-36
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发表时间：
2014-02-24
期刊：
影响因子：
37.3
通讯作者：
Juhnn YS
中科院分区：
文献类型：
--
作者：
Cho EA;Kim EJ;Kwak SJ;Juhnn YS
共济失调-毛细血管扩张突变 (ATM) 蛋白激酶在协调细胞对辐射引起的 DNA 损伤的反应中发挥着核心作用。 cAMP 信号传导调节各种细胞反应，包括代谢和基因表达。本研究旨在探讨 cAMP 信号传导调节 ATM 激活和肺癌细胞对电离辐射的细胞反应的机制。用组成型活性刺激G蛋白（GαsQL）转染肺癌细胞，并用γ射线照射。通过蛋白质印迹分析ATM和蛋白磷酸酶2A的磷酸化，并通过蛋白质印迹、流式细胞术和TUNNEL染色评估细胞凋亡。通过双荧光素酶报告基因测定测定 NF-κB 启动子活性。用毛喉素治疗 BALB/c 小鼠以评估对肺组织的影响。 GαsQL 的瞬时表达显着抑制 H1299 人肺癌细胞中辐射诱导的 ATM 磷酸化。用冈田酸处理或敲低 PP2A B56δ 亚基消除了 Gαs 对辐射诱导的 ATM 磷酸化的抑制作用。 GαsQL 的表达增加了 B56δ 的磷酸化和 PP2A 活性，而 PKA 的抑制则阻止了 Gαs 诱导的 PP2A 激活。 GαsQL 增强了辐射诱导的 caspase-3 和 PARP 裂解，并增加了早期凋亡细胞的数量。通过使用 PDTC 抑制 NF-κB 或使用 KU55933 或针对 ATM 的 siRNA 抑制 ATM，可以增加辐射诱导的细胞凋亡。用毛喉素预处理 BALB/c 小鼠可刺激 PP2A B56δ 的磷酸化，抑制 ATM 和 NF-κB 的激活，并增强辐射诱导的肺组织细胞凋亡。 H1299 细胞经 γ 射线照射后，GαsQL 表达降低了 p50 和 p65 亚基的核水平以及 NF-κB 依赖性活性。前列腺素 E2 或异丙肾上腺素预处理可增加 B56δ 磷酸化，减少辐射诱导的 ATM 磷酸化并增加细胞凋亡。 cAMP 信号传导通过 PKA 依赖性的 PP2A 激活来抑制辐射诱导的 ATM 激活，并且这种信号传导机制通过减少肺癌细胞中 ATM 依赖性的 NF-κB 激活来增强辐射诱导的细胞凋亡。
The ataxia–telangiectasia mutated (ATM) protein kinase plays a central role in coordinating the cellular response to radiation-induced DNA damage. cAMP signaling regulates various cellular responses including metabolism and gene expression. This study aimed to investigate the mechanism through which cAMP signaling regulates ATM activation and cellular responses to ionizing radiation in lung cancer cells. Lung cancer cells were transfected with constitutively active stimulatory G protein (GαsQL), and irradiated with γ-rays. The phosphorylation of ATM and protein phosphatase 2A was analyzed by western blotting, and apoptosis was assessed by western blotting, flow cytometry, and TUNNEL staining. The promoter activity of NF-κB was determined by dual luciferase reporter assay. BALB/c mice were treated with forskolin to assess the effect in the lung tissue. Transient expression of GαsQL significantly inhibited radiation-induced ATM phosphorylation in H1299 human lung cancer cells. Treatment with okadaic acid or knock down of PP2A B56δ subunit abolished the inhibitory effect of Gαs on radiation-induced ATM phosphorylation. Expression of GαsQL increased phosphorylation of the B56δ and PP2A activity, and inhibition of PKA blocked Gαs-induced PP2A activation. GαsQL enhanced radiation-induced cleavage of caspase-3 and PARP and increased the number of early apoptotic cells. The radiation-induced apoptosis was increased by inhibition of NF-κB using PDTC or inhibition of ATM using KU55933 or siRNA against ATM. Pretreatment of BALB/c mice with forskolin stimulated phosphorylation of PP2A B56δ, inhibited the activation of ATM and NF-κB, and augmented radiation-induced apoptosis in the lung tissue. GαsQL expression decreased the nuclear levels of the p50 and p65 subunits and NF-κB-dependent activity after γ-ray irradiation in H1299 cells. Pretreatment with prostaglandin E2 or isoproterenol increased B56δ phosphorylation, decreased radiation-induced ATM phosphorylation and increased apoptosis. cAMP signaling inhibits radiation-induced ATM activation by PKA-dependent activation of PP2A, and this signaling mechanism augments radiation-induced apoptosis by reducing ATM-dependent activation of NF-κB in lung cancer cells.
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影响因子：
13.8
作者：
Ditch, Scott;Paull, Tanya T.
通讯作者：
Paull, Tanya T.
影响因子：
4.3
作者：
Golding, Sarah E.;Rosenberg, Elizabeth;Valerie, Kristoffer
通讯作者：
Valerie, Kristoffer
影响因子：
5.7
作者：
Choi, Yoon Jung;Oh, Jung-Min;Juhnn, Yong-Sung
通讯作者：
Juhnn, Yong-Sung
影响因子：
7.2
作者：
Lee, Y;McKinnon, PJ
通讯作者：
McKinnon, PJ
DOI：
10.1111/j.1748-1716.2011.02273.x
发表时间：
2012-02
期刊：
Acta physiologica (Oxford, England)
影响因子：
--
作者：
Insel PA;Zhang L;Murray F;Yokouchi H;Zambon AC
通讯作者：
Zambon AC