11218

DDX20

DEAD (Asp-Glu-Ala-Asp) box polypeptide 20;DDX20;DEAD (Asp-Glu-Ala-Asp) box polypeptide 20

DEAD box protein 20|DEAD box protein DP 103|DEAD-box protein DP103|DEAD/H (Asp-Glu-Ala-Asp/His) box polypeptide 20, 103kD|SMN-interacting protein|component of gems 3|gemin-3|probable ATP-dependent RNA helicase DDX20

1p21.1-p13.2

protein-coding

Despite advancement in breast cancer treatment, 30% of patients with early breast cancers experience relapse with distant metastasis. It is a challenge to identify patients at risk for relapse; therefore, the identification of markers and therapeutic targets for metastatic breast cancers is imperative. Here, we identified DP103 as a biomarker and metastasis-driving oncogene in human breast cancers and determined that DP103 elevates matrix metallopeptidase 9 (MMP9) levels, which are associated with metastasis and invasion through activation of NF-kappaB. In turn, NF-kappaB signaling positively activated DP103 expression. Furthermore, DP103 enhanced TGF-beta-activated kinase-1 (TAK1) phosphorylation of NF-kappaB-activating IkappaB kinase 2 (IKK2), leading to increased NF-kappaB activity. Reduction of DP103 expression in invasive breast cancer cells reduced phosphorylation of IKK2, abrogated NF-kappaB-mediated MMP9 expression, and impeded metastasis in a murine xenograft model. In breast cancer patient tissues, elevated levels of DP103 correlated with enhanced MMP9, reduced overall survival, and reduced survival after relapse. Together, these data indicate that a positive DP103/NF-kappaB feedback loop promotes constitutive NF-kappaB activation in invasive breast cancers and activation of this pathway is linked to cancer progression and the acquisition of chemotherapy resistance. Furthermore, our results suggest that DP103 has potential as a therapeutic target for breast cancer treatment.