Class I histone deacetylases 1, 2 and 3 are highly expressed in renal cell cancer

Background Enhanced activity of histone deacetylases (HDAC) is associated with more aggressive tumour behaviour and tumour progression in various solid tumours. The over-expression of these proteins and their known functions in malignant neoplasms has led to the development of HDAC inhibitors (HDI) as new anti-neoplastic drugs. However, little is known about HDAC expression in renal cell cancer. Methods We investigated the expression of HDAC 1, 2 and 3 in 106 renal cell carcinomas and corresponding normal renal tissue by immunohistochemistry on tissue micro arrays and correlated expression data with clinico-pathological parameters including patient survival. Results Almost 60% of renal cell carcinomas expressed the HDAC isoforms 1 and 2. In contrast, HDAC 3 was only detected in 13% of all renal tumours, with particular low expression rates in the clear cell subtype. HDAC 3 was significantly higher expressed in pT1/2 tumours in comparison to pT3/4 tumours. Expression of class I HDAC isoforms correlated with each other and with the proliferative activity of the tumours. We found no prognostic value of the expression of any of the HDAC isoforms in this tumour entity. Conclusion Class I HDAC isoforms 1 and 2 are highly expressed in renal cell cancer, while HDAC 3 shows low, histology dependent expression rates. These unexpected differences in the expression patterns suggests alternative regulatory mechanisms of class I HDACs in renal cell cancer and should be taken into account when trials with isoform selective HDI are being planned. Whether HDAC expression in renal cancers is predictive of responsiveness for HDI will have to be tested in further studies

Der Einfluss von Ethanol auf die Autoimmunantwort an einem Mausmodell der rheumatoiden Arthritis

Rheumatoide Arthritis (RA) ist die häufigste chronische Autoimmunerkrankung der Gelenke. Hierbei kommt es zu einer Entzündung des Synoviums, was im Verlauf der Erkrankung Knorpelabbau und Knochenerosionen zur Folge hat und schließlich zum Funktionsverlust des betroffenen Gelenks führt. Mehrere Studien sehen einen Zusammenhang von moderatem Alkoholkonsum und einem protektiven Effekt auf die Entstehung und den Verlauf der RA. Auch im Mausmodell für RA erkranken durch Alkohol-Behandlung weniger Mäuse und rheumatische Symptome treten später und mit geringerer Ausprägung auf. Bislang konnten jedoch die Mechanismen der supprimierenden Wirkung des Alkohols auf das Immunsystem bei der RA nicht aufgeklärt werden. Im Rahmen dieser Doktorarbeit sollte daher der molekulare Mechanismus aufgedeckt werden, dem die Minderung der Inzidenz der Kollagen-induzierten Arthritis (CIA) durch Verabreichung von Ethanol zugrunde liegt, um mögliche neue therapeutische Ansätze für die Behandlung der RA zu finden. Dabei sollte zunächst der Phänotyp alkoholbehandelter CIA-Mäuse geprüft werden. Anschließend sollte der Einfluss von Alkohol auf Krankheitsmarker im Serum und die Immunzellen im Verlauf der CIA untersucht werden. Die Behandlung der CIA mit Ethanol im Trinkwasser resultierte in einer stark verminderten Inzidenz, wobei die gesunden CIA-Mäuse keine histologischen Anzeichen einer Gelenksentzündung aufwiesen. Auch die durchflusszytometrische Analyse entzündlicher Zellen zeigte kaum Einwanderung von neutrophilen Granulozyten in die Pfoten. Anhand der Bildgebung mittels µComputertomografie wurde auch die Integrität der Knochen in diesen Mäusen bestätigt. Die CIA-Mäuse, die final keine arthritischen Symptome unter Ethanol-Behandlung zeigten, wiesen ebenso eine reduzierte Akut-Phase-Reaktion auf, worauf geringere Konzentrationen von Serum Amyloid P hindeuteten. Zudem wurden zwei Wochen nach der ersten Immunisierung signifikant weniger lymphoide dendritische Zellen in der Milz dieser Mäuse identifiziert. Vermutlich hervorgerufen durch weniger IL-21 produzierende TFH-Zellen ließen die gesunden CIA-Mäuse ebenso eine herabgesetzte Keimzentrums-Reaktion erkennen, worauf kleinere Follikel und weniger Keimzentrums-B-Zellen in der Milz hinwiesen. Dieses resultierte in weniger Plasmazellen und Kollagen-Antikörper-produzierenden Zellen in Milz und Knochenmark. Entsprechend zeigten die gesunden CIA-Mäuse eine geringere Anzahl Kollagen-spezifischer Antikörper vom IgG1 Subtyp in der Zirkulation. Auch der Sialylierungs-Grad des gesamt-IgGs war in diesen Mäusen erhöht. Zusammen identifizieren die hier gezeigten Ergebnisse IL-21 als vielversprechenden Angriffspunkt für einen therapeutischen Ansatz zur Behandlung der RA.Rheumatoid Arthritis (RA) is the most common chronic autoimmune disease of the joints. This causes inflammation of the synovium, resulting in cartilage degradation and bone erosions in the course of the disease and finally leads to loss of function of the affected joint. Several studies show a relationship between moderate alcohol consumption and a protective effect on the development and the course of RA. Even in a mouse model for RA, fewer mice are affected by alcohol treatment and rheumatic symptoms occur later and with a lesser extent. To date, however, the mechanism of the suppressing effect of alcohol on the immune system in RA has not been elucidated. The scope of this thesis was to disclose the molecular mechanism which is based on the reduction of the incidence of collagen-induced arthritis (CIA) by administration of ethanol, to find possible new therapeutic approaches for the treatment of RA. Therefore, the phenotype of alcohol-treated CIA mice should be examined. Subsequently, the influence of alcohol on disease markers in the serum as well as on immune cells in the course of CIA should be investigated. Treatment of CIA with ethanol in drinking water resulted in a markedly reduced incidence, with no histological signs of joint inflammation in healthy CIA mice. Also the analysis of inflammatory cells by flow cytometry showed just few immigrated neutrophilic granulocytes in the paws. The integrity of the bones in these mice was also confirmed by using microcomputer tomography imaging. CIA mice which did not show any arthritic symptoms under ethanol treatment had also a reduced acute phase response, indicated by lower concentrations of serum amyloid P. Furthermore, two weeks after the first immunization, significantly less lymphoid dendritic cells were identified in the spleen of these mice. Presumably caused by less IL-21-producing TFH cells, healthy CIA mice also exhibited a decreased germinal center reaction, designated by smaller follicles and less germinal center B cells in the spleen. This resulted in fewer plasma cells and collagen-antibody-producing cells in spleen and bone marrow. Likewise, healthy CIA mice had smaller numbers of collagen-specific IgG1 antibodies in the circulation. Also the sialylation level of the total IgG was increased in these mice. Collectively, the results shown here identify IL-21 as a promising candidate for a therapeutic approach for the treatment of RA

Investigation of Wall Shear Stress in Cardiovascular Research and in Clinical Practice—From Bench to Bedside

In the 1900s, researchers established animal models experimentally to induce atherosclerosis by feeding them with a cholesterol-rich diet. It is now accepted that high circulating cholesterol is one of the main causes of atherosclerosis; however, plaque localization cannot be explained solely by hyperlipidemia. A tremendous amount of studies has demonstrated that hemodynamic forces modify endothelial athero-susceptibility phenotypes. Endothelial cells possess mechanosensors on the apical surface to detect a blood stream-induced force on the vessel wall, known as “wall shear stress (WSS)”, and induce cellular and molecular responses. Investigations to elucidate the mechanisms of this process are on-going: on the one hand, hemodynamics in complex vessel systems have been described in detail, owing to the recent progress in imaging and computational techniques. On the other hand, investigations using unique in vitro chamber systems with various flow applications have enhanced the understanding of WSS-induced changes in endothelial cell function and the involvement of the glycocalyx, the apical surface layer of endothelial cells, in this process. In the clinical setting, attempts have been made to measure WSS and/or glycocalyx degradation non-invasively, for the purpose of their diagnostic utilization. An increasing body of evidence shows that WSS, as well as serum glycocalyx components, can serve as a predicting factor for atherosclerosis development and, most importantly, for the rupture of plaques in patients with high risk of coronary heart disease

The Involvement of Cx43 in JNK1/2-Mediated Endothelial Mechanotransduction and Human Plaque Progression

Atherosclerotic lesions preferentially develop at bifurcations, characterized by non-uniform shear stress (SS). The aim of this study was to investigate SS-induced endothelial activation, focusing on stress-regulated mitogen-activated protein kinases (MAPK) and downstream signaling, and its relation to gap junction proteins, Connexins (Cxs). Human umbilical vein endothelial cells were exposed to flow (“mechanical stimulation”) and stimulated with TNF-α (“inflammatory stimulation”). Phosphorylated levels of MAPKs (c-Jun N-terminal kinase (JNK1/2), extracellular signal-regulated kinase (ERK), and p38 kinase (p38K)) were quantified by flow cytometry, showing the activation of JNK1/2 and ERK. THP-1 cell adhesion under non-uniform SS was suppressed by the inhibition of JNK1/2, not of ERK. Immunofluorescence staining and quantitative real-time PCR demonstrated an induction of c-Jun and c-Fos and of Cx43 in endothelial cells by non-uniform SS, and the latter was abolished by JNK1/2 inhibition. Furthermore, plaque inflammation was analyzed in human carotid plaques (n = 40) using immunohistochemistry and quanti-gene RNA-assays, revealing elevated Cx43+ cell counts in vulnerable compared to stable plaques. Cx43+ cell burden in the plaque shoulder correlated with intraplaque neovascularization and lipid core size, while an inverse correlation was observed with fibrous cap thickness. Our results constitute the first report that JNK1/2 mediates Cx43 mechanoinduction in endothelial cells by atheroprone shear stress and that Cx43 is expressed in human carotid plaques. The correlation of Cx43+ cell counts with markers of plaque vulnerability implies its contribution to plaque progression

MSI testing What is new? What should be considered? German version

Based on new trial data regarding immune checkpoint inhibitors (ICIs), the detection of high-grade microsatellite instability (MSI-H) or underlying deficient mismatch repair protein (dMMR) is now becoming increasingly important for predicting treatment response. For the first time, a PD-1 ICI (pembrolizumab) has been approved by the European Medicines Agency (EMA) for first-line treatment of advanced (stage IV) dMMR/MSI-H colorectal cancer (CRC). Further indications, such as dMMR/MSI-H endometrial carcinoma (EC), have already succeeded (Dostarlimab, 2nd line treatment) and others are expected to follow before the end of 2021. The question of optimal testing in routine diagnostics should therefore be re-evaluated. Based on a consideration of the strengths and weaknesses of the widely available methods (immunohistochemistry and PCR), a test algorithm is proposed that allows quality assured, reliable, and cost-effective dMMR/MSI-H testing. For CRC and EC, testing is therefore already possible at the primary diagnosis stage, in line with international recommendations (NICE, NCCN). The clinician is therefore enabled from the outset to consider not only the predictive but also the prognostic and predispositional implications of such a test when counseling patients and formulating treatment recommendations. As a basis for quality assurance, participation in interlaboratory comparisons and continuous documentation of results (e.g., QuIP Monitor) are strongly recommended

MSI testing What's new? What should be considered?

Based on new trial data regarding immune checkpoint inhibitors (ICIs), the detection of high-grade microsatellite instability (MSI-H) or underlying deficient mismatch repair protein (dMMR) is now becoming increasingly important for predicting treatment response. For the first time, a PD-1 ICI (pembrolizumab) has been approved by the European Medicines Agency (EMA) for first-line treatment of advanced (stage IV) dMMR/MSI-H colorectal cancer (CRC). Further indications, such as dMMR/MSI-H endometrial carcinoma (EC), have already succeeded (Dostarlimab, 2nd line treatment) and others are expected to follow before the end of 2021. The question of optimal testing in routine diagnostics should therefore be re-evaluated. Based on a consideration of the strengths and weaknesses of the widely available methods (immunohistochemistry and PCR), a test algorithm is proposed that allows quality assured, reliable, and cost-effective dMMR/MSI-H testing. For CRC and EC, testing is therefore already possible at the primary diagnosis stage, in line with international recommendations (NICE, NCCN). The clinician is therefore enabled from the outset to consider not only the predictive but also the prognostic and predispositional implications of such a test when counseling patients and formulating treatment recommendations. As a basis for quality assurance, participation in interlaboratory comparisons and continuous documentation of results (e.g., QuIP Monitor) are strongly recommended