Matrix metalloproteinase 9 is a mediator of epidermal growth factor-dependent e-cadherin loss in ovarian carcinoma cells

Abstract Epidermal growth factor (EGF) receptor (EGFR) is frequently elevated in epithelial ovarian cancer, and E-cadherin expression is often reduced in advanced disease. In this study, we investigated a mechanism by which EGFR activation promotes disruption of adherens junctions through induction of matrix metalloproteinase 9 (MMP-9). We show that EGFR activation down-modulates E-cadherin, and broad spectrum MMP inhibition ameliorates EGF-stimulated junctional disruption and loss of E-cadherin protein. MMP-9 involvement in EGFdependent down-regulation of E-cadherin was determined by siRNA specifically directed against MMP-9. Furthermore, treatment with recombinant MMP-9 or transient expression of MMP-9 is sufficient to reduce E-cadherin levels in differentiated ovarian tumor cells. Stable overexpression of MMP-9 led to a loss of E-cadherin and junctional integrity, and promoted a migratory and invasive phenotype. Thus, elevated MMP-9 protein expression is sufficient for junctional disruption and loss of E-cadherin in these cells. The associations between EGFR activation, MMP-9 expression, and E-cadherin were investigated in human ovarian tumors and paired peritoneal metastases wherein immunohistochemical staining for activated (phospho) EGFR and MMP-9 colocalized with regions of reduced E-cadherin. These data suggest that regulation of MMP-9 by EGFR may represent a novel mechanism for downmodulation of E-cadherin in ovarian cancer. [Cancer Res 2008;68(12):4606-13

Urothelial-Type adenocarcinoma of the prostate mimicking metastatic colorectal adenocarcinoma

Adenocarcinoma arising in urinary bladder or prostatic urethra is uncommon. When they occur, the tumor can be mistaken for metastatic lesions, especially from the colon. Here we report the fifth case of a primary urothelial-type adenocarcinoma arising in the prostate which showed enteric differentiation. The patient was a 55 year-old male whose prostatic needle core biopsy showed a high grade adenocarcinoma which was initially thought to be metastatic colon cancer. A follow-up colonoscopy was unremarkable. Subsequent prostatectomy revealed a high grade adenocarcinoma which was positive for cytokeratins 7 and 20, carcinoembryonic antigen, CDX2, and high molecular weight cytokeratin, and negative for prostate specific antigen, prostate specific acid phosphatase and AMACR. A diagnosis of urothelial-type adenocarcinoma of the prostate was rendered. We review the literature regarding this entity, and discuss the differential diagnosis, emphasizing utility of immunohistochemistry in making the diagnosis. Finally, we speculate on the behavior of these rare tumors