| First Author | Bist P | Year | 2011 |
| Journal | Oncogene | Volume | 30 |
| Issue | 28 | Pages | 3174-85 |
| PubMed ID | 21383699 | Mgi Jnum | J:174635 |
| Mgi Id | MGI:5140266 | Doi | 10.1038/onc.2011.28 |
| Citation | Bist P, et al. (2011) Annexin-1 interacts with NEMO and RIP1 to constitutively activate IKK complex and NF-kappaB: implication in breast cancer metastasis. Oncogene 30(28):3174-85 |
| abstractText | The molecular mechanisms underlying constitutive nuclear factor-kappaB (NF-kappaB) activation in solid tumors has not been elucidated. We show that Annexin-1 (ANXA1) is involved in this process, and suppression of ANXA1 in highly metastatic breast cancer cells impedes migration and metastasis capabilities in vitro and in vivo. ANXA1 expression correlates with NF-kappaB activity, suggesting that ANXA1 may be required for the constitutive activity of IkappaB kinase (IKK) and NF-kappaB in highly metatstatic breast cancer. Gel-filtration analysis demonstrated that ANXA1 co-elutes with the members of the IKK complex and NF-kappaB signaling pathway, and immunoprecipitation confirmed that ANXA1 can bind to and interact with IKKgamma or NEMO, but not IKKalpha or IKKbeta. Importantly, silencing of ANXA1 prevents the interaction of NEMO and RIP1, which indicates that ANXA1 is required for the recruitment of RIP1 to the IKK complex, which may be important for the activation of NF-kappaB. Downstream targets of NF-kappaB include uPA and CXCR4, which can be modulated by ANXA1 silencing. CXCR4-mediated migration of breast cancer cell lines in response to CXCL12 was significantly modulated by ANXA1, indicating its importance in the tissue-specific migration of breast cancer cells. Chromatin immunoprecipitation experiments confirmed that in ANXA1 overexpressed cells, NF-kappaB was recruited to CXCR4 promoter without external stimulation, indicating that ANXA1 is critical for the constitutive activation of NF-kappaB in breast cancer to promote metastasis. Finally, we show that ANXA1 overexpression enhances metastasis and reduces survival in an intracardiac metastasis model, while ANXA1-deficient mice crossed with MMTV-PyMT mice display significantly less metastasis than their heterozygous littermates, indicating that ANXA1 is an important gene in breast cancer metastasis. Our data reveal that ANXA1 can constitutively activate NF-kappaB in breast cancer cells through the interaction with the IKK complex, and suggests that modulating ANXA1 levels has therapeutic potential to suppress breast cancer metastasis. |
