MiR-205-driven downregulation of cholesterol biosynthesis through SQLE-inhibition identifies therapeutic vulnerability in aggressive prostate cancer.

Prostate cancer (PCa) shows strong dependence on the androgen receptor (AR) pathway. Here, we show that squalene epoxidase (SQLE), an enzyme of the cholesterol biosynthesis pathway, is overexpressed in advanced PCa and its expression correlates with poor survival. SQLE expression is controlled by micro-RNA 205 (miR-205), which is significantly downregulated in advanced PCa. Restoration of miR-205 expression or competitive inhibition of SQLE led to inhibition of de novo cholesterol biosynthesis. Furthermore, SQLE was essential for proliferation of AR-positive PCa cell lines, including abiraterone or enzalutamide resistant derivatives, and blocked transactivation of the AR pathway. Inhibition of SQLE with the FDA approved antifungal drug terbinafine also efficiently blocked orthotopic tumour growth in mice. Finally, terbinafine reduced levels of prostate specific antigen (PSA) in three out of four late-stage PCa patients. These results highlight SQLE as a therapeutic target for the treatment of advanced PCa.

PIAS1 is a determinant of poor survival and acts as a positive feedback regulator of AR signaling through enhanced AR stabilization in prostate cancer.

Novel drugs like Abiraterone or Enzalutamide, which target androgen receptor (AR) signaling to improve androgen deprivation therapy (ADT), have been developed during the past years. However, the application of these drugs is limited because of occurrence of inherent or acquired therapy resistances during the treatment. Thus, identification of new molecular targets is urgently required to improve current therapeutic prostate cancer (PCa) treatment strategies. PIAS1 (protein inhibitor of activated STAT1 (signal transducer and activator of transcription-1)) is known to be an important cell cycle regulator and PIAS1-mediated SUMOylation is essential for DNA repair. In this context, elevated PIAS1 expression has already been associated with cancer initiation. Thus, in the present study, we addressed the question of whether PIAS1 targeting can be used as a basis for an improved PCa therapy in combination with anti-androgens. We show that PIAS1 significantly correlates with AR expression in PCa tissue and in cell lines and demonstrate that high PIAS1 levels predict shorter relapse-free survival. Our patient data are complemented by mechanistic and functional in vitro experiments that identify PIAS1 as an androgen-responsive gene and a crucial factor for AR signaling via prevention of AR degradation. Furthermore, PIAS1 knockdown is sufficient to decrease cell proliferation as well as cell viability. Strikingly, Abiraterone or Enzalutamide treatment in combination with PIAS1 depletion is even more effective than single-drug treatment in multiple PCa cell models, rendering PIAS1 as a promising target protein for a combined treatment approach to improve future PCa therapies.

The Use of Transitional Care Models in Patients With Stroke.

BACKGROUND: Transitional care (TC) models are used to reduce adverse outcomes and hospital readmissions. This article reviews the scholarly literature to identify TC models that have been used successfully in patients with stroke. METHODS: Literature in CINAHL, PubMed, and the Cochrane Database of Systematic Reviews from January 2000 to June 2013 was searched using the keywords "transitional care," "discharge planning," "care-coordination," "continuity of care," "follow-up after discharge," and "stroke." Web sites of established TC models were also reviewed to identify additional studies meeting review criteria. To be included in the review, studies must have been written in the English language and focused on adult patients aged 19 years and older with stroke, discharged from the hospital or acute rehabilitation facility to home. TC interventions were defined as those that employed one or more of the National Transitions of Care Coalition intervention categories: medication management, transition planning, patient and family engagement or education, information transfer, follow-up care, healthcare provider engagement, or shared accountability across providers and organizations (National Transitions of Care Coalition, 2011). The author examined the title and abstract of each study for eligibility against stated criteria. RESULTS: Thirteen articles representing 11 studies were found to meet the inclusion criteria. In the identified studies, TC was compared with usual care; however, what constituted usual care was not consistently elucidated. Fewer than half of the studies reported significantly improved results on selected outcomes. Across all the studies, TC did not result in a reported significant decrease in emergency department visits or hospital readmission rates. There was substantive heterogeneity in (a) intervention providers, (b) interventions used in TC, and (c) measures of outcome identified. Six of the 13 studies were identified as having successful interventions. CONCLUSION: Some evidence exists to support positive outcomes using TC in patients with stroke. Standardization of interventions and outcome measures is needed to determine the most effective interventions. Additional large-scale randomized, controlled trials should be undertaken to provide reliable data regarding effective TC interventions for persons after stroke.

EpCAM is overexpressed in local and metastatic prostate cancer, suppressed by chemotherapy and modulated by MET-associated miRNA-200c/205.

BACKGROUND: Expression of epithelial cell adhesion molecule (EpCAM) is deregulated in epithelial malignancies. Beside its role in cell adhesion, EpCAM acts as signalling molecule with tumour-promoting functions. Thus, EpCAM is part of the molecular network of oncogenic receptors and considered an interesting therapeutic target. METHODS: Here, we thoroughly characterised EpCAM expression on mRNA and protein level in comprehensive tissue studies including non-cancerous prostate specimens, primary tumours of different grades and stages, metastatic lesions, and therapy-treated tumour specimens, as well as in prostate cancer cell lines. RESULTS: Epithelial cell adhesion molecule was overexpressed at mRNA and at protein level in prostate cancer tissues and cell lines. Altered EpCAM expression was an early event in prostate carcinogenesis with an upregulation in low-grade cancers and further induction in high-grade tumours and metastatic lesions. Interestingly, EpCAM was repressed upon induction of epithelial-to-mesenchymal transition (EMT) following chemotherapeutic treatment with docetaxel. Oppositely, re-induction of the epithelial phenotype through miRNAs miR-200c and miR-205, two inducers of mesenchymal-to-epithelial transition (MET), led to re-induction of EpCAM in chemoresistant cells. Furthermore, we prove that EpCAM cleavage, the first step of EpCAM signalling takes place in prostate cancer cells but in contrast to other cancer entities, EpCAM has no measurable impact on the proliferative behaviour of prostate cells, in vitro. CONCLUSIONS: In conclusion, our data confirm that EpCAM overexpression is an early event during prostate cancer progression. Epithelial cell adhesion molecule displays a dynamic, heterogeneous expression and associates with epithelial cells rather than mesenchymal, chemoresistant cells along with processes of EMT and MET.

[Androgens stimulate the expression of SOCS-3 and inhibits their effect on proliferation and secretion]. / C. E. Alken Preis 2007: Androgene stimulieren die Expression von SOCS-3 und bewirken die Inhibition der Proliferation und Sekretion.

PURPOSE: Suppressors of cytokine signalling (SOCS) are induced by interleukins and peptide hormones. These molecules prevent the activation of diverse signalling pathways in benign and malignant cells. In previous studies, we showed that SOCS-3 is expressed in most prostate cancer cell lines and tissue specimens. In the present study we investigated the effects of androgen on the regulation of SOCS-3 in prostate cancer cell lines. MATERIALS AND METHODS: SOCS-3 expression was determined with PCR and Western blot techniques. The activity of the SOCS-3 promoter was measured with the luciferase test. We measured proliferation with (3)H-thymidine assay. RESULTS: We show that androgen induces the expression of SOCS-3 in two prostate cancer cell lines. The non-steroidal anti-androgen bicalutamide is able to block the induction of SOCS-3 -expression. Androgenic hormones did not induce the expression of SOCS-3 mRNA or its promoter activity. In LNCaP-IL-6- cells transfected with the inducible Tet-On construct SOCS-3 expression was induced. The effects of androgenic hormones on the proliferation and induction of PSA were -diminished in the presence of SOCS-3. CONCLUSIONS: Our results show that androgenic -regulation of SOCS-3 leads to inhibition of prolif-eration and secretion in human prostate cancer.