Dickkopf-3 (Dkk-3) is a secreted protein whose expression is downregulated in many types of cancer. Endogenous Dkk-3 is required for formation of acini in 3D cultures of prostate epithelial cells, where it inhibits transforming growth factor (TGF)-β/Smad signaling. Here, we examined the effects of Dkk-3 on the expression and activity of matrix metalloproteases (MMPs), which mediate the effects of TGF-β on extracellular matrix disassembly during tissue morphogenesis and promote invasion of tumor cells. Silencing of Dkk-3 in prostate epithelial cells resulted in increased expression and enzyme activity of MMP-2 and MMP-9. Inhibition of MMP-9 partially restored normal acinar morphogenesis in Dkk-3-silenced RWPE-1 prostate epithelial cells. In PC3 prostate cancer cells, Dkk-3 inhibited TGF-β-dependent migration and invasion. Inhibition was mediated by the Dkk-3 C-terminal cysteine-rich domain (Cys2), which also inhibited TGF-β-induced expression of MMP9 and MMP13. In contrast, Dkk-3, but not Cys2, increased formation of normal acini in Dkk-3-silenced prostate epithelial cells. These observations highlight a role for Dkk-3 in modulating TGF-β/MMP signals in the prostate, and suggest that the Dkk-3 Cys2 domain can be used as a basis for therapies that target the tumor promoting effects of TGF-β signaling in advanced prostate cancer.
This article discusses the results of two collection assessments conducted at the University of Illinois at Urbana-Champaign. The library s Preservation Committee completed the first assessment and reported its results in College & Research Libraries in 1989. The second assessment was completed in 2002 and accompanies the institution’s initiative to establish the library’s first centralized preservation and conservation program. Both assessments focused on the central stacks collection, a repository collection serving the institution’s forty-two branch and departmental libraries. Although a reanalysis of the first assessment s data was impossible, the authors attempted to draw comparisons between the two assessments’ results. After thirteen years without a preservation program and without any significant facilities improvements, the results provide insight into the results of deferred collections care and facilities maintenance and offer guidance for conducting similar studies with other research library collections.
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