DDX17-Mediated Upregulation of CXCL8 Promotes Hepatocellular Carcinoma Progression via Co-activating β-catenin/NF-κB Complex.

Abstract

Hepatocellular carcinoma (HCC) is a well-known inflammation-related cancer, that accounts for fifth most prevalent neoplasm and the third major driver of cancer associated fatality globally. Accumulating evidence has elucidated that C-X-C motif chemokine ligands (CXCLs) are aberrantly upregulated in HCC and are involved in inflammation-induced hepatocarcinogenesis and metastasis. Herein, we identified a novel function of DEAD-box RNA helicase 17 (DDX17) as an oncogenic factor via transactivating CXCL8 in HCC. Unlike the adjacent nontumor tissues, DDX17 was highly expressed in tumor tissues compared in two independent cohorts and that it acts as an independent prognostic indicator for patients who have HCC. Mechanistically, DDX17 interacts with β-catenin and NF-κB, and promotes their nuclear translocation to promote the transcription of the inflammatory gene CXCL8, thus promoting HCC proliferation and invasion in vitro and in vivo. More interestingly, stimulation with recombinant human CXCL8 augmented the interaction of NF-κB with DDX17/β-catenin and enhanced its autocrine activation by promoting the phosphorylation of IκBα. Furthermore, blocking the association of the DDX17/β-catenin/NF-κB complex with a CXCR1/2 inhibitor markedly abrogated DDX17-mediated HCC proliferation and metastasis. Overall, this study provided new insights into DDX17-mediated pro-inflammatory chemokine activation, which unveiled the association between DDX17 and β-catenin/ NF-κB complex in transactivating the expression of CXCL8. The usage of CXCR1/2 inhibitor to block DDX17-induced CXCL8 signaling activation might be a potential therapeutic approach for HCC treatment.