Impact of fractalkin and mfg-e8 on platelet activation and their interaction with pharmacologic platelet inhibitors

Die genauen Mechanismen der frühen Atheroskleroseentstehung sind Thema intensiver Forschungsarbeit. Hierbei hat sich in den letzten Jahren eine zunehmend wichtige Rolle für Thrombozyten herauskristallisiert. Sie spielen nicht nur in der Hämostase, sondern auch bei immunologischen und entzündlichen Erkrankungen eine wichtige Rolle. Aktivierte Blutplättchen interagieren auf vielfältige Weise mit unterschiedlichen Zellen ihrer Umgebung – Endothelzellen, glatten Muskelzellen oder Leukozyten – wodurch es auf beiden Seiten zur Freisetzung von Botenstoffen und nachfolgend zur Aktivierung diverser Signalwege kommt. Auf der Thrombozytenoberfläche finden sich u.a. Rezeptoren für das Chemokin Fractalkin (CX3CL1). Dieses wurde bereits mit Thrombozytenaktivierung und Leukozytenadhäsion am Endothel in Verbindung gebracht. In dieser Arbeit konnte erstmals gezeigt werden, dass der thrombozytäre ADP-Rezeptor P2Y12 und der Rezeptor für Fractalkin, CX3CR1, eine ähnliche intrazelluläre G-Protein-Kopplung und Signalkaskade aufweisen, die in der Aktivierung der PI3K mündet. Der Effekt ist unabhängig von einer ADP-Zugabe und wird über G vermittelt, so dass hierüber eine Blockung des P2Y12-Rezeptors durch z.B. Clopidogrel umgangen werden könnte. Des Weiteren ist bekannt, dass Fractalkin die Expression des Glykoproteins mfg-e8 beeinflusst. Inwiefern mfg-e8 einen Einfluss auf Thrombozyten hat, ist bislang nur unzureichend erforscht. In der vorliegenden Arbeit konnte eine proaktivierende Wirkung von mfg-e8 auf Thrombozyten nachgewiesen werden: Sowohl im Western blot (Aktivierung der PI3K) wie auch durchflusszytometrisch (Aktivierung des GPIIb/IIIa). Unter arteriellen Flussbedingungen schwächte mfg-e8 die Bindung von Thrombozyten an Fibrinogen-beschichtete Oberflächen ab. Welche Rezeptoren an dieser Interaktion beteiligt sind, ist derzeit nicht geklärt. Sowohl mfg-e8 als auch Fractalkin stellen interessante, thrombozytenaktivierenden Substanzen dar, deren Einfluss aufeinander und auf das Gefäßsystem weiterführender Untersuchung bedarf.Platelets are crucially involved in early development of atherosclerosis. They interact with multiple cells in their environment which activates diverse signalling pathways. On the platelet surface chemokine receptors, amongst others, receptors for fractalkine (CX3CL1), can be found. Here, we show for the first time that ADP-receptor P2Y12 and fractalkine-receptor CX3CR1 have a similar intracellular pathway which leads to activation of PI3K. Once released from an atherosclerotic lesion, this mechanism could contribute locally to impaired clopidogrel responsiveness at the vulnerable plaque. Furthermore, fractalkine influences the expression of glycoprotein mfg-e8. We prove a pro-activating effect of mfg-e8 on platelets in Western Blot and flow cytometry. Yet, the detailed mechanism and the involved receptors still remain unclear

Holmium Laser Enucleation of the Prostate Provides Similar Incidental Prostate Cancer Detection Rates as Open Prostatectomy: A Matched Pair Analysis

Introduction: Whereas the excellent functional outcomes after Holmium laser enucleation of the prostate (HoLEP) and its equivalency to open prostatectomy (OP) have been studied in detail in the past years, the oncological equivalency has yet to be investigated. Therefore, we conducted a matched pair analysis to evaluate and compare incidental prostate cancer detection rates after HoLEP and OP. Patients and methods: Preoperative patient age, total prostate-specific antigen (PSA), and prostate volume were used as primary matching criteria. Descriptive statistics were used to confirm matching quality. Statistical analyses were performed using Fisher ' s exact test and T-test or Mann-Whitney U-test for dichotomous and continuous variables, respectively. Results: After the matching procedure, 72 out of 145 patients after HoLEP and 72 out of 477 patients after OP were included. Mean patient age (70 vs. 71 years), median prostate volume (106 vs. 107 mL), and median preoperative total PSA (4.32 vs. 4.36 ng/mL) were almost identical. The amount of removed tissue did not differ between HoLEP and OP. Incidental prostate cancer detection rate was similar with 9.7% after HoLEP and 8.3% after OP (p = 1.000). Conclusion: This first matched pair analysis shows that HoLEP does not have a disadvantage regarding cancer detection rate during desobstructive surgery for large prostates. (C) 2018 S. Karger AG, Basel

Strong Expression of Cancertestis Antigens CTAG1B and MAGEA3 Is Correlated with Unfavourable Histopathological Features and MAGEA3 Is Associated with Worse Progression-Free Survival in Urothelial Bladder Cancer

Background: Cancer/testis antigens (CTA) are expressed in urothelial bladder cancer (UBC). Their therapeutical and prognostic relevance remains unclear. We studied the correlation of MAGEA3 and CTAG1B with histopathological factors in UBC and their prognostic value. Methods: Retrospective analysis of 93 patients who underwent treatment for UBC was conducted. Besides clinical and histopathological parameters, the expression of MAGEA3 and CTAG1B was assessed by immunohistochemistry. Results: Median follow-up was 75 months. Fifteen per cent of patients showed strong positive reaction to MAGEA3 staining. These tumours were statistically and significantly more often correlated with unfavourable World Health Organization (WHO) grading (G1: 0%, G2: 10.3%, G3: 23.4%, p = 0.048; low grade 0%, high grade 18.4%, p = 0.046 respectively). Correlation of CTAG1B with WHO grading was impressive with strong expression in no G1, 31.1% of G2 and 51.1% of G3 tumours (low grade 0%, high grade 43.4%, p = 0.001, respectively). Concomitant carcinoma in situ (Cis) was associated with strong CTAG1B expression (54.2% in concomitant Cis vs. 29% without concomitant Cis, p = 0.026). Kaplan-Meier analysis revealed statistically and significantly worse 5 years progression-free survival (PFS) associated with a strong expression of MAGEA3 (59 vs. 84%, p = 0.032). Conclusions: Strong CTA expression was correlated with unfavourable histopathological features. A strong expression of MAGEA3 was statistically and significantly associated with worse PFS across all stages of UBC. (C) 2018 S Karger AG, Base

Impact of E-Cadherin and β-Catenin as Prognostic Factor in Renal Cell Carcinoma with Tumor Thrombus of the Vena Cava

Purpose: Renal cell carcinoma (RCC) forming tumor thrombus (TT) of vena cava (VC) is characterized by poor prognosis. Nevertheless, the outcome of patients after radical surgery varies. To date only limited data concerning prognostic biomarkers in this RCC subgroup are available. Methods: Out of 159 patients with pT3b/c RCC, 95 patients without synchronous distant metastases at time of diagnosis were included in the study cohort. After immunohistochemical (IHC) evaluation of E-cadherin and beta-Catenin expression, association with clinical, histopathological and survival was assessed by univariate analysis, multivariate analysis, and Kaplan-Meier-analysis. Cancer-specific survival (CSS) rates and overall survival (OS) rates were estimated using Kaplan-Meier analysis and compared using Log rank test. Results: We found a significant correlation between E-cadherin overexpression and initial lymph node metastasis (rho = 0.300, p = 0.003), positive surgical margins (rho = 0.210, p = 0.043), and the development of distant metastases (rho = 0.258, p = 0.012). Furthermore, we observed a significant correlation of beta-Catenin overexpression with higher tumor stage pT3c (rho = 0.230, p = 0.028) and initial lymph node metastases (rho = 0.236, p = 0.025). Survival analysis revealed a statistically significant association of both E-cadherin and beta-Catenin overexpression with worse CSS (p < 0.001 and p = 0.007, respectively) and OS (p < 0.001 and p = 0.041, respectively). Multivariate analysis revealed initial lymph node metastasis as the only predictive factor for worse OS (HR 4.54, 95% CI 2.30-8.93; p < 0.001). E-Cadherin and beta-Catenin expression failed to be significant in multivariable analysis for OS and CSS. Conclusions: In a large series of RCC with TT of VC high IHC expression of E-cadherin and beta-Catenin was associated with initial lymph node metastasis and with both worse OS and worse CSS. This might help to identify patients at risk for recurrence who might benefit from adjuvant therapy or stricter follow-up. (c) 2019 S. Karger AG, Base

Improved prediction of nephron-sparing surgery versus radical nephrectomy by the optimized R.E.N.A.L. Score in patients undergoing surgery for renal masses

BACKGROUND: One major objective of currently available morphometric scores (MS) for renal masses, i.e., R.E.N.A.L., PADUA classification, Centrality-Index, is the prediction of type of surgery (nephron-sparin surgery [NSS] or radical nephrectomy [RN]). METHODS: Based on a prospective study protocol, various MS were assigned and calculated for 108 patients undergoing surgical treatment for renal masses at a single academic center. MS calculation was based on preoperative computed-tomography or magnet-resonance-imaging and performed by two independent readers blinded for surgical approach and outcome. Multivariable logistic-regression- and ROC-analyses were performed to assess the predictive value of various MS for surgical approach and the correlation of clinical parameters with nephrectomy type. Furthermore, the association with perioperative outcome parameters was evaluated. RESULTS: None of the tested MS was significantly superior to tumor size alone (area under the curve [AUC]=0.82) in predicting RN, with Centrality-Index showing the best association (AUC-0.88). Based on these findings, a simplified and optimized R.E.N.A.L. Score (optR.E.N.A.L.) was developed with different weightings of included parameters, which did not only show a significantly enhanced association with surgery type (AUC=0.93) than tumor size, but also outperformed all 1st and 2nd generation MS tested in the study cohort. Besides a modest correlation with postoperative change in renal function, no association with perioperative outcome variables was found for all MS including optR.E.N.A.L.. CONCLUSIONS: optR.E.N.A.L. represents a promising improvement of the preexisting R.E.N.A.L. Score with higher predictive ability for nephrectomy type than established MS and may serve as a benchmarking tool for nephrectomy assessment and comparison of surgical strategies