Abstract | BACKGROUND/AIMS: METHODS: Immunohistochemistry, immunofluorescence and western blotting were applied to detect the levels of oxidized ATM. Transwell assay was used to detect the cell migration and invasion abilities in different treatments. Quantitative phosphoproteome analysis was performed using hypoxic BT549 cells, in the presence or absence of Ku60019, a specific inhibitor of ATM kinase. The phosphorylated cortactin, the target protein of oxidized ATM, was confirmed by immunoprecipitation-western blots and in vitro kinase assay. The functions of phosphorylated cortactin were studied by specific short hairpin RNA, site-directed mutation, transwell assay, and actin polymerization assay. RESULTS: Enhanced oxidized ATM proteins were present not only in the advanced and invasive breast tumor tissues but also malignant hypoxic breast cancer cells, in the absence of DNA damage. Loss of ATM expression or inhibiting oxidized ATM kinase activity reduced breast cancer cell migration and invasion. Using quantitative phosphoproteomics approach, 333 oxidized ATM target proteins were identified, some of these proteins govern key signaling associated with gap junction, focal adhesion, actin cytoskeleton rearrangement. Cortactin, one of the biggest changed phospho- protein, is a novel oxidized ATM-dependent target in response to hypoxia. Mechanically, we reveal that hypoxia-activated ATM can enhance the binding affinity of cortactin with Arp2/3 complex by phosphorylating cortactin at serine 113, and as a result, in favor of breast cancer cell migration and invasion. CONCLUSION: Oxidized ATM can phosphorylate cortactin at serine 113, playing a critical role in promoting breast tumor cell mobility and invasion via actin polymerization.
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Authors | Lei Lang, Yixuan Hou, Yanlin Chen, Gang Tu, Jing Tao, Dan Yang, Lei Xi, Lixin Fu, Kexin Sun, Jiali Yin, Rui Chen, Meixi Peng, Shuiqing Liu, Manran Liu |
Journal | Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology
(Cell Physiol Biochem)
Vol. 51
Issue 6
Pg. 2972-2988
( 2018)
ISSN: 1421-9778 [Electronic] Germany |
PMID | 30562756
(Publication Type: Journal Article)
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Copyright | © 2018 The Author(s). Published by S. Karger AG, Basel. |
Chemical References |
- Actins
- CTTN protein, human
- Cortactin
- ATM protein, human
- Ataxia Telangiectasia Mutated Proteins
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Topics |
- Actins
(analysis, metabolism)
- Ataxia Telangiectasia Mutated Proteins
(analysis, metabolism)
- Breast Neoplasms
(metabolism, pathology)
- Cell Line, Tumor
- Cell Movement
- Cortactin
(analysis, metabolism)
- Disease Progression
- Female
- Humans
- Neoplasm Invasiveness
(pathology)
- Phosphorylation
- Polymerization
- Tumor Hypoxia
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