Impact of JNK1, JNK2, and ligase Itch on reactive oxygen species formation and survival of prostate cancer cells treated with diallyl trisulfide
Impact of JNK1, JNK2, and ligase Itch on reactive oxygen species formation and survival of prostate cancer cells treated with diallyl trisulfide
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DOI：
10.1007/s00394-011-0241-0
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发表时间：
2012-08-01
影响因子：
5
通讯作者：
Antosiewicz, Jedrzej
中科院分区：
文献类型：
--
作者：
Sielicka-Dudzin, Alicja;Borkowska, Andzelika;Antosiewicz, Jedrzej
在我们之前的研究中，我们证明了二烯丙基三硫化物(DATS)诱导铁依赖的前列腺癌细胞周期的G2-M期停滞。此外，铁蛋白的降解和不稳定铁库的增加与JNK信号轴的激活有关。在目前的工作中，我们扩展了这项研究，以确定哪些c-jun激酶负责铁蛋白的降解，以及铁在DATS诱导的细胞死亡中的作用。我们假设JNK1激活瘙痒连接酶，这将导致铁蛋白泛素化，增加铁依赖的ROS形成和细胞死亡。本研究使用PC-3前列腺癌细胞。测定细胞存活率、ROS浓度、活性铁库、铁蛋白和P-Itch的变化及DNA损伤，观察DATS通过JNK、Itch信号轴诱导铁蛋白降解。在JNK1-dN细胞中，DATS不诱导ROS的形成，也不增加LIP。我们还观察到DATS增加了JNK依赖的E3连接酶Itch的激活磷酸化。转染失活型Itch的细胞对DATS的细胞毒性有较强的抵抗力，且DATS诱导的铁蛋白降解较低。去铁胺是一种特异性的铁螯合剂，对细胞活力和DNA损伤没有影响。这些结果表明，JNK1依赖的LIP增加是由Itch泛素连接酶介导的。
In our previous study, we demonstrated that diallyl trisulfide (DATS) induced iron-dependent G2-M arrest of prostate cancer cell cycle. Moreover, ferritin degradation and an increase of labile iron pool has been linked to the activation of the JNK signaling axis. In the present work, we extended this study to determine which of the c-jun kinases is responsible for ferritin degradation and the role of iron in DATS-induced cell death. We hypothesized that JNK1 activates Itch ligase which will lead to ferritin ubiquitination, an increase in iron-dependent ROS formation and cell death.PC-3 prostate cancer cells were used in this study. Cell viability, concentration of ROS, labile iron pool, and changes in ferritin and P-Itch and DNA damage were determined.We observed that DATS induced ferritin degradation through JNK, Itch signaling axis. DATS did not induce neither ROS formation nor increase the LIP in JNK1-DN transfected cells. We also observed that DATS increased JNK-dependent activating phosphorylation of E3ligase Itch. The cells transfected with inactive form of Itch were more resistant against cytotoxicity of DATS and showed lower DATS-induced ferritin degradation. Desferrioxamine a specific iron chelator had no effect neither on cell viability nor DNA damage evaluated by comet assay.These results suggest that JNK1-dependent increase in LIP is mediated by Itch ubiquitin ligase.