S100A4 (metastasin-1), a metastasis-associated protein and marker of the epithelial to mesenchymal transition, contributes to several hallmarks of cancer and has been implicated in the progression of several types of cancer. However, the impacts of S100A4 signaling in lung cancer progression and its potential use as a target for therapy in lung cancer have not been properly explored. Using established lung cancer cell lines, we demonstrate that S100A4 knockdown reduces cell proliferation, invasion and three-dimensional invasive growth, while overexpression of S100A4 increases invasive potential. In patient-derived tissues, S100A4 is preferentially elevated in lung adenocarcinoma. This elevation is associated with lymphovascular invasion and decreased overall survival. In addition, depletion of S100A4 by shRNA inhibits NF-κB activity and decreases TNFα-induced MMP9 expression. Furthermore, inhibition of the NF-κB/MMP9 axis decreases lung carcinoma invasive potential. Niclosamide, a reported inhibitor of S100A4, blocks expression and function of S100A4 with a reduction in proliferation, invasion and NF-κB-mediated MMP9 expression. Collectively, this study highlights the importance of the S100A4/NF-κB/MMP9 axis in lung cancer invasion and provides a rationale for targeting S100A4 to combat lung cancer.

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Background: Integrin ␣6␤4 is overexpressed in pancreatic cancer and enhances invasion. Results: Integrin ␣6␤4 coordinately up-regulates AREG, EREG, and MMP1 through DNA demethylation and NFAT5 that in turn enhances HGF-mediated invasion. Conclusion: Integrin ␣6␤4 stimulates HGF-dependent invasion through autocrine EGFR signaling. Significance: HGF-stimulated invasion is dependent on autocrine EGFR signaling, thus implicating why EGFR inhibitors are effective in a complex tumor microenvironment.