Matrix metalloproteinases (MMPs) play an important role in tumor progression and metastasis. Here, we investigated the prognostic relevance of MMP‐7 in urinary bladder cancer. MMP‐7 gene expression was measured in tissue samples of 101 patients using quantitative real‐time PCR. Circulating MMP‐7 serum levels of 98 individuals (79 patients and 19 controls) were analyzed by enzyme‐linked immunosorbent assay. The results were compared with the clinical follow‐up data, performing Kaplan–Meier log‐rank test as well as univariate and multivariate Cox analysis. In representative cases, immunohistochemical analysis for MMP‐7 was performed. We detected significantly elevated MMP‐7 levels both in tissue and serum samples of patients with metastatic disease (P = 0.001 and P = 0.002). Multivariate analysis revealed that high MMP‐7 tissue expression and serum concentration are stage‐ and grade‐independent predictors of both metastasis‐free (hazard ratio [HR] = 3.80, 95% confidence interval [CI], 1.29–11.23, P = 0.016, and HR = 2.53, 95% CI, 1.01–6.37, P = 0.048) and disease‐specific survival (HR = 1.89, 95% CI, 1.00–3.55, P = 0.050 and HR = 1.95, 95% CI, 1.03–3.71, P = 0.041). Based on these findings, we conclude that MMP‐7 is a promising marker to detect present and to predict future metastasis. Serum MMP‐7 analysis provides information about the risk of metastasis before surgery which could help to optimize therapeutic procedures. Furthermore, high MMP‐7 tissue and/or serum levels could identify patients most likely to benefit from early adjuvant chemotherapy.(Cancer Sci 2010; 101: 1300–1308)

Urothelial carcinoma (UC) is the fifth most common cancer in the developed world. Delineation of differentiation subtypes in UC highlighted the importance of aberrant differentiation. Understanding underlying mechanisms may facilitate diagnosis and development of efficient therapy strategies. It is well accepted that epigenetic mechanisms are involved. Long noncoding RNAs (lncRNAs), a new class of epigenetic factors, are thought to mediate molecular differences between cell types to control cellular identity. The present study focuses on the lncRNA HOTAIR, originating from the HOXC locus. Its overexpression induces an aggressive phenotype in many cancers and aberrant expression of homeotic HOX transcription factors, especially HOXD10, that regulate differentiation and tissue homeostasis. The aim of the present study was to determine the functional role of HOTAIR in UC with regard to aggressive phenotype, regulation of aberrant differentiation and altered HOX gene expression. We determined RNA expression levels of HOTAIR and HOX genes in UC tissues and cell lines. Knockdown of HOTAIR and ectopic overexpression was performed to determine the effect on reported target genes in UC. Cell lines were stably transfected with HOTAIR to investigate changes in phenotype and HOX gene expression. HOTAIR was overexpressed in approximately half of UC tissues and cell lines. Effects of HOTAIR overexpression differed between cell lines. Whereas VM-CUB1 cells acquired the expected phenotype with increased proliferation, clonogenicity, anchorage independent growth, migratory activity and epithelial-to-mesenchymal transition, 5637 cells grew more slowly displaying induction of senescence and related immune response genes. Other UC lines showed intermediate effects. Expression profiling revealed divergent effects on HOX genes, cell cycle regulators and differentiation according with the phenotypic differences between HOTAIR-overexpressing VM-CUB1 and 5637 cells. Our data indicate that HOTAIR overexpression may affect differentiation state and aggressiveness of UC cells, but in a cell-type dependent manner. Our functional studies and the comparison of our expression data sets with those from other cancer cell types, which revealed minimal overlaps, indicate that effects of HOTAIR are strongly tissue-dependent and can even differ within one cancer type. Thus, HOTAIR functions and target genes cannot simply be transferred from one cancer type to the other.

Prostate-specific membrane antigen (PSMA)-directed radioligand therapy (RLT) prolongs overall survival in men with metastatic castration-resistant prostate cancer (mCRPC). However, men with low PSMA expression are excluded from RLT. We explored the effect of androgen receptor blockade with enzalutamide on PSMA expression. Assessment of PSMA and androgen receptor (AR) expression on the human PC cell lines 22Rv1, C4-2, and LNCaP by immunohistochemistry and flow cytometry revealed low (22Rv1) and high (C4-2 and LNCaP) PSMA expression, and high, comparable AR positivity. Treatment with enzalutamide increased PSMA levels in 22Rv1, C4-2, and LNCaP (2.2/2.3/2.6-fold, p = 0.0005/0.03/0.046) after one week compared to DMSO-treated controls as assessed by flow cytometry. NOD/Scid mice bearing 22Rv1 tumors were treated with enzalutamide for two weeks. Positron emission tomography/computed tomography (PET/CT) demonstrated higher tumor uptake of ⁶⁸Ga-PSMA after enzalutamide treatment (p = 0.004). Similarly, a clinical case with low baseline PSMA avidity demonstrated increased uptake of ⁶⁸Ga-PSMA after enzalutamide on PET/CT and post-therapeutic ¹⁷⁷Lu-PSMA scintigraphy in a patient with mCRPC. Enzalutamide induced PSMA expression in the 22Rv1 xenograft model and in an mCRPC patient, both with low baseline tumoral PSMA levels. Therefore, enzalutamide pre-treatment might render patients with low PSMA expression eligible for ¹⁷⁷Lu-PSMA RLT.

Elevated matrix metalloproteinase‐7 (MMP‐7) tissue expression and serum concentration have been shown to be associated with cancer progression and metastasis. The aim of our study was to assess the prognostic value of preoperative circulating MMP‐7 levels in serum samples of patients with clinically localized prostate cancer. Furthermore, we compared the serum MMP‐7 levels between patients with organ confined and metastatic prostate cancer. MMP‐7 levels were measured in 93 patients with localized prostate cancer, 13 patients with distant bone metastasis and in sera of 19 controls using enzyme‐linked immunosorbent assay. The results were compared to the clinical follow‐up data. We did not find any significant difference in MMP‐7 serum levels between patients and controls (p = 0.268). Circulating MMP‐7 serum concentration was significantly elevated in patients with distant metastasis (p < 0.001). For the detection of distant prostate cancer metastasis, using a cut‐off value of 3.7 ng/ml, a specificity of 69% and a sensitivity of 92% were observed. Multivariate analysis identified high MMP‐7 serum concentration as an independent risk factor for prostate cancer‐related death both in a preoperative and a postoperative model (p = 0.003 and 0.018, respectively). Furthermore, the evaluation of predictive models revealed that addition of serum MMP‐7 levels to the preoperatively available predictors improves prognostic accuracy (the concordance index increased from 0.631 to 0.734 when MMP‐7 was included). Based on these, we concluded that MMP‐7 is a potential marker to identify patients with metastatic prostate cancer. In clinically localized prostate cancer, MMP‐7 may provide independent prognostic information, thereby helping to optimize therapy decisions.