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Prostate-derived Ets transcription factor (PDEF) has recently been associated with invasive breast cancer, but no expression profile has been defined in clinical specimens. We undertook a comprehensive PDEF transcriptional expression study of 86 breast cancer clinical specimens, several cell lines, and normal tissues. PDEF expression profile was analyzed according to standard clinicopathologic parameters and compared with hormonal receptor and HER-2/neu status and to the expression of the new tumor biomarker Dikkopf-1 (DKK1). Wide ranging PDEF overexpression was observed in 74% of tested tumors, at higher levels than the average expression found in normal breasts. High PDEF expression was associated with hormone receptor positivity (P < .001), moderate to good differentiation (less than grade III, P = .01), and dissemination to axillary lymph nodes (P = .002). PDEF was an independent risk factor for nodal involvement (multivariate analysis, odds ratio 1.250, P = .002). It was expressed in a different subgroup compared to DKK1-expressing tumors (P < .001). Our data imply that PDEF mRNA expression could be useful in breast cancer molecular staging. Further insights into PDEF functions at the protein level, and possible links with hormone receptors biology, bear great potential for new therapeutic avenues.

Background: The increased synthesis of matrix metalloproteinases (MMPs) by aortic smooth muscle cells (SMCs) is thought to be involved in the etiopathogenesis of abdominal aortic aneurysms (AAAs), but the functional regulation and the activation states of these MMPs remain unclear. In this study, we assessed the expression levels and the functional regulation of several MMPs in the pathogenesis of AAAs. Methods: Human healthy aorta and AAA specimens were homogenized, and the proteolytic activities of MMP-2 and MMP-9 and of the macrophage metalloelastase (MMP-12) were assessed with zymography. Protein expression of MMP-1, MMP-12, membrane-type 1 MMP (MT1-MMP), tissue inhibitor of MMP 1 (TIMP-1), TIMP-2, TIMP-3, α-actin, and β-actin was analyzed with electrophoresis on sodium dodecyl sulfate gels and immunoblotting. Results: MMP-1, MMP-9, and MMP-12 zymogen levels and proteolytic activities were increased in AAAs when compared with healthy aorta. A severe reduction in α-actin–positive vascular SMCs was observed in all the AAA specimens and was correlated with an increase in TIMP-3 but not TIMP-1 or TIMP-2 potential activities. Although pro–MMP-2 activity was decreased, the extent of activated MMP-2 remained unaffected in the AAAs. In accordance with this result, a highly activated MT1-MMP form was also observed in AAAs. Conclusion: These data suggest that chronic aortic wall inflammation is mediated by macrophage infiltration, which may account for the destruction of medial elastin, as reflected by SMC down regulation, through increased levels of active MMP-1 and MMP-12. Moreover, altered MT1-MMP proteolytic turnover and differential regulation of TIMP expression in AAAs suggest that tight regulatory mechanisms are involved in the molecular regulation of MMP activation processes in the pathogenesis of AAAs. (J Vasc Surg 2002;35:539-46.)