CDK16 Phosphorylates and Degrades p53 to Promote Radioresistance and Predicts Prognosis in Lung Cancer.
CDK16 Phosphorylates and Degrades p53 to Promote Radioresistance and Predicts Prognosis in Lung Cancer.
复制标题
CDK16 磷酸化和降解 p53 以促进放射抗性并预测肺癌的预后
作者：
Xie J;Li Y;Jiang K;Hu K;Zhang S;Dong X;Dai X;Liu L;Zhang T;Yang K;Huang K;Chen J;Shi S;Zhang Y;Wu G;Xu S
理由：放射抗性被认为是肺癌局部复发的主要原因。然而，人们对放射抗性的分子机制仍知之甚少。本研究探讨 CDK16 在人肺癌细胞放射抗性中的作用。方法：采用免疫组化法检测肺癌组织及癌旁正常肺组织中CDK16的表达水平。利用免疫沉淀测定和 GST Pulldown 来检测蛋白质-蛋白质相互作用。通过体外激酶测定评估p53的磷酸化。通过体内泛素化测定检查 p53 的多聚泛素化。测量细胞生长和凋亡、ROS 水平和 DNA 损伤反应以进行功能分析。结果：我们发现CDK16在肺癌细胞和组织中经常过表达，高水平的CDK16与肺癌患者的淋巴结分期和不良预后相关。此外，我们提供了证据表明 CDK16 与 p53 Ser315 位点结合并磷酸化 p53，从而抑制 p53 的转录活性。此外，我们发现这种磷酸化修饰通过泛素/蛋白酶体途径加速 p53 降解。重要的是，我们证明 CDK16 通过抑制细胞凋亡和 ROS 产生以及以 p53 依赖性方式抑制肺癌细胞中的 DNA 损伤反应来促进放射抗性。结论：我们的研究结果表明，CDK16 负向调节 p53 信号通路以促进放射抗性，因此是肺癌放疗的一个有前途的治疗靶点。
Rationale: Radioresistance is considered the main cause of local relapse in lung cancer. However, the molecular mechanisms of radioresistance remain poorly understood. This study investigates the role of CDK16 in radioresistance of human lung cancer cells. Methods: The expression levels of CDK16 were determined by immunohistochemistry in lung cancer tissues and adjacent normal lung tissues. Immunoprecipitation assay and GST pulldown were utilized to detect the protein-protein interaction. The phosphorylation of p53 was evaluated by in vitro kinase assay. Poly-ubiquitination of p53 was examined by in vivo ubiquitination assay. Cell growth and apoptosis, ROS levels and DNA damage response were measured for functional analyses. Results: We showed that CDK16 is frequently overexpressed in lung cancer cells and tissues, and high levels of CDK16 are correlated with lymph node stage and poor prognosis in lung cancer patients. Furthermore, we provided evidence that CDK16 binds to and phosphorylates p53 at Ser315 site to inhibit transcriptional activity of p53. Moreover, we uncovered that this phosphorylation modification accelerates p53 degradation via the ubiquitin/proteasome pathway. Importantly, we demonstrated that CDK16 promotes radioresistance by suppressing apoptosis and ROS production as well as inhibiting DNA damage response in lung cancer cells in a p53-dependent manner. Conclusion: Our findings suggest that CDK16 negatively modulates p53 signaling pathway to promote radioresistance, and therefore represents a promising therapeutic target for lung cancer radiotherapy.
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DOI：
10.1042/bcj20160941
发表时间：
2017-02-20
期刊：
The Biochemical journal
影响因子：
--
作者：
Dixon-Clarke SE;Shehata SN;Krojer T;Sharpe TD;von Delft F;Sakamoto K;Bullock AN
通讯作者：
Bullock AN
影响因子：
13.6
作者：
Dai C;Gu W
通讯作者：
Gu W
影响因子：
11.4
作者：
Reinhardt, H. Christian;Schumacher, Bjoern
通讯作者：
Schumacher, Bjoern
影响因子：
4.6
作者：
Mokalled, Mayssa H.;Johnson, Aaron;Olson, Eric N.
通讯作者：
Olson, Eric N.
影响因子：
4.8
作者：
Cho, Hyun Jung;Oh, Yun Jung;Kim, Hongtae
通讯作者：
Kim, Hongtae