1. Interaction with cyclin H/cyclin-dependent kinase 7 (CCNH/CDK7) stabilizes C-terminal binding protein 2 (CtBP2) and promotes cancer cell migration
- Author
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Qinlei Hang, Yingying Wang, Fang Liu, Xiaodong Huang, Song He, Yuchan Wang, Huijie Wang, Feng Mao, Chun Cheng, Tianyi Zhang, Aiguo Shen, and Guangfei Xu
- Subjects
Cyclin H ,Proteasome Endopeptidase Complex ,genetic processes ,Repressor ,Nerve Tissue Proteins ,Biology ,Transfection ,Biochemistry ,environment and public health ,Cyclin-dependent kinase ,Cell Movement ,Cell Line, Tumor ,Neoplasms ,Protein Interaction Mapping ,Humans ,Cycloheximide ,Neoplasm Metastasis ,Molecular Biology ,Protein Synthesis Inhibitors ,Kinase ,Cell migration ,Cell Biology ,Cyclin-Dependent Kinases ,Cell biology ,Protein Structure, Tertiary ,Gene Expression Regulation, Neoplastic ,stomatognathic diseases ,enzymes and coenzymes (carbohydrates) ,Alcohol Oxidoreductases ,HEK293 Cells ,Cancer cell ,Cancer research ,biology.protein ,Cyclin-dependent kinase 7 ,biological phenomena, cell phenomena, and immunity ,Co-Repressor Proteins ,Cyclin-Dependent Kinase-Activating Kinase ,Protein Binding - Abstract
CtBP2 has been demonstrated to possess tumor-promoting capacities by virtue of up-regulating epithelial-mesenchymal transition (EMT) and down-regulating apoptosis in cancer cells. As a result, cellular CtBP2 levels are considered a key factor determining the outcome of oncogenic transformation. How pro-tumorigenic and anti-tumorigenic factors compete for fine-tuning CtBP2 levels is incompletely understood. Here we report that the cyclin H/cyclin-dependent kinase 7 (CCNH/CDK7) complex interacted with CtBP2 in vivo and in vitro. Depletion of either CCNH or CDK7 decreased CtBP2 protein levels by accelerating proteasome-dependent CtBP2 clearance. Further analysis revealed that CCNH/CDK7 competed with the tumor repressor HIPK2 for CtBP2 binding and consequently inhibited phosphorylation and dimerization of CtBP2. Phosphorylation-defective CtBP2 interacted more strongly with CCNH/CDK7 and was more resistant to degradation. Finally, overexpression of CtBP2 increased whereas depletion of CtBP2 dampened the invasive and migratory potential of breast cancer cells. CtBP2 promoted the invasion and migration of breast cancer cells in a CCNH-dependent manner. Taken together, our data have delineated a novel pathway that regulates CtBP2 stability, suggesting that targeting the CCNH/CDK7-CtBP2 axis may yield a viable anti-tumor strategy.
- Published
- 2013