Refine
Has Fulltext
- yes (14)
Is part of the Bibliography
- yes (14)
Document Type
- Journal article (14)
Keywords
- DNA methylation (3)
- Bipolar disorder (2)
- Laborleistungstests (2)
- Minisequenzierung (2)
- Multiple myeloma (2)
- Pyrosequenzierung (2)
- laboratory proficiency testing (2)
- minisequencing (2)
- pyrosequencing (2)
- Angiopoietin-like 4 (1)
Institute
- Klinik und Poliklinik für Psychiatrie, Psychosomatik und Psychotherapie (5)
- Theodor-Boveri-Institut für Biowissenschaften (3)
- Institut für Humangenetik (2)
- Institut für Rechtsmedizin (2)
- Institut für Virologie und Immunbiologie (2)
- Medizinische Klinik und Poliklinik II (2)
- Institut für Psychologie (1)
- Klinik und Poliklinik für Kinder- und Jugendpsychiatrie, Psychosomatik und Psychotherapie (1)
- Lehrstuhl für Orthopädie (1)
- Pathologisches Institut (1)
Chemotherapy, the standard treatment for pancreatic ductal adenocarcinoma (PDAC), has only a modest effect on the outcome of patients with late-stage disease. Investigations of the genetic features of PDAC have demonstrated a frequent occurrence of mutations in genes involved in homologous recombination (HR), especially in the breast cancer susceptibility gene 2 (BRCA2). Olaparib, a poly(ADP-ribose) polymerase (PARP) inhibitor, is approved as a maintenance treatment for patients with advanced PDAC with germline BRCA1/2 mutations following a platinum-containing first-line regimen. Limitations to the use of PARP inhibitors are represented by the relatively small proportion of patients with mutations in BRCA1/2 genes and the modest capability of these substances of inducing objective response. We have previously shown that pancreatic cancer with BRCA2 mutations exhibits a remarkably enhanced sensitivity towards tumor-necrosis-factor-related apoptosis-inducing ligand (TRAIL) receptor-stimulating agents. We thus aimed to investigate the effect of combined treatment with PARP inhibitors and TRAIL receptor-stimulating agents in pancreatic cancer and its dependency on the BRCA2 gene status. The respective effects of TRAIL-targeting agents and the PARP inhibitor olaparib or of their combination were assessed in pancreatic cancer cell lines and patient-derived organoids. In addition, BRCA2-knockout and -complementation models were investigated. The effects of these agents on apoptosis, DNA damage, cell cycle, and receptor surface expression were assessed by immunofluorescence, Western blot, and flow cytometry. PARP inhibition and TRAIL synergized to cause cell death in pancreatic cancer cell lines and PDAC organoids. This effect proved independent of BRCA2 gene status in three independent models. Olaparib and TRAIL in combination caused a detectable increase in DNA damage and a concentration-dependent cell cycle arrest in the G2/M and S cell cycle phases. Olaparib also significantly increased the proportion of membrane-bound death receptor 5. Our results provide a preclinical rationale for the combination of PARP inhibitors and TRAIL receptor agonists for the treatment of pancreatic cancer and suggest that the use of PARP inhibitors could be extended to patients without BRCA2 mutations if used in combination with TRAIL agonists.
Mit der Entdeckung altersabhängiger epigenetischer Veränderungen, der DNA-Methylierung (DNAm), hat sich eine neue Möglichkeit aufgezeigt, das Alter eines Individuums zu schätzen. Die Methode wurde intensiv erforscht und ihre Anwendung in der forensischen Fallarbeit durch die Aktualisierung des § 81e der Strafprozessordnung (StPO) in Deutschland reguliert. Zur Untersuchung des DNAm-Grades müssen neue Techniken etabliert und validiert werden. Dies macht die Prüfung der Vergleichbarkeit von Messergebnissen aus verschiedenen forensischen Laboren erforderlich.
Hierzu führte die Arbeitsgruppe „Molekulare Altersschätzung“ der Deutschen Gesellschaft für Rechtsmedizin (DGRM) im Winter 2019/2020 den 2. Ringversuch (RV) zur quantitativen DNAm-Analyse mithilfe der Mini- und der Pyrosequenzierung durch. Dieser basierte auf den Erfahrungen des 1. RV 2018/2019, dessen Ergebnisse in dieser Ausgabe ebenfalls vorgestellt werden. Die aktuelle Studie umfasst Analyseergebnisse aus 12 Laboren (ingesamt 14 teilnehmende Labore), von denen einige beide Methoden angewandt haben. Zusätzlich führten 4 Labore eine Altersschätzung an den RV-Proben mit eigenen Markerkombinationen und Modellen durch. Da diese auf unterschiedlichen Referenzdaten und Markerkombinationen beruhen, erfolgte kein qualitativer Vergleich der Modelle, sondern das grundsätzliche Potenzial der Methodik wurde verdeutlicht. Ziele des RV waren die Evaluierung der Vergleichbarkeit der DNAm-Messungen und die Bewertung möglicher Einflussfaktoren, wie Extraktionsmethode und verwendetes Gerät.
Die Ergebnisse zeigen, dass sich die gemessenen DNAm-Werte der untersuchten Marker sowohl zwischen Mini- und Pyrosequenzierung als auch innerhalb der jeweiligen Methode zwischen den Laboren unterscheiden können, sodass mit Schwankungen gerechnet werden muss.
Multiple myeloma remains a largely incurable disease of clonally expanding malignant plasma cells. The bone marrow microenvironment harbors treatment-resistant myeloma cells, which eventually lead to disease relapse in patients. In the bone marrow, CD4\(^{+}\)FoxP3\(^{+}\) regulatory T cells (Tregs) are highly abundant amongst CD4\(^{+}\) T cells providing an immune protective niche for different long-living cell populations, e.g., hematopoietic stem cells. Here, we addressed the functional role of Tregs in multiple myeloma dissemination to bone marrow compartments and disease progression. To investigate the immune regulation of multiple myeloma, we utilized syngeneic immunocompetent murine multiple myeloma models in two different genetic backgrounds. Analyzing the spatial immune architecture of multiple myeloma revealed that the bone marrow Tregs accumulated in the vicinity of malignant plasma cells and displayed an activated phenotype. In vivo Treg depletion prevented multiple myeloma dissemination in both models. Importantly, short-term in vivo depletion of Tregs in mice with established multiple myeloma evoked a potent CD8 T cell- and NK cell-mediated immune response resulting in complete and stable remission. Conclusively, this preclinical in-vivo study suggests that Tregs are an attractive target for the treatment of multiple myeloma.
Using Illumina 450K arrays, 1.85% of all analyzed CpG sites were significantly hypermethylated and 0.31% hypomethylated in fetal Down syndrome (DS) cortex throughout the genome. The methylation changes on chromosome 21 appeared to be balanced between hypo- and hyper-methylation, whereas, consistent with prior reports, all other chromosomes showed 3-11times more hyper- than hypo-methylated sites. Reduced NRSF/REST expression due to upregulation of DYRK1A (on chromosome 21q22.13) and methylation of REST binding sites during early developmental stages may contribute to this genome-wide excess of hypermethylated sites. Upregulation of DNMT3L (on chromosome 21q22.4) could lead to de novo methylation in neuroprogenitors, which then persists in the fetal DS brain where DNMT3A and DNMT3B become downregulated. The vast majority of differentially methylated promoters and genes was hypermethylated in DS and located outside chromosome 21, including the protocadherin gamma (PCDHG) cluster on chromosome 5q31, which is crucial for neural circuit formation in the developing brain. Bisulfite pyrosequencing and targeted RNA sequencing showed that several genes of PCDHG subfamilies A and B are hypermethylated and transcriptionally downregulated in fetal DS cortex. Decreased PCDHG expression is expected to reduce dendrite arborization and growth in cortical neurons. Since constitutive hypermethylation of PCDHG and other genes affects multiple tissues, including blood, it may provide useful biomarkers for DS brain development and pharmacologic targets for therapeutic interventions.
Physical interaction of skeletal precursors with multiple myeloma cells has been shown to suppress their osteogenic potential while favoring their tumor-promoting features. Although several transcriptome analyses of myeloma patient-derived mesenchymal stem cells have displayed differences compared to their healthy counterparts, these analyses insufficiently reflect the signatures mediated by tumor cell contact, vary due to different methodologies, and lack results in lineage-committed precursors. To determine tumor cell contact-mediated changes on skeletal precursors, we performed transcriptome analyses of mesenchymal stem cells and osteogenic precursor cells cultured in contact with the myeloma cell line INA-6. Comparative analyses confirmed dysregulation of genes which code for known disease-relevant factors and additionally revealed upregulation of genes that are associated with plasma cell homing, adhesion, osteoclastogenesis, and angiogenesis. Osteoclast-derived coupling factors, a dysregulated adipogenic potential, and an imbalance in favor of anti-anabolic factors may play a role in the hampered osteoblast differentiation potential of mesenchymal stem cells. Angiopoietin-Like 4 (ANGPTL4) was selected from a list of differentially expressed genes as a myeloma cell contact-dependent target in skeletal precursor cells which warranted further functional analyses. Adhesion assays with full-length ANGPTL4-coated plates revealed a potential role of this protein in INA6 cell attachment. This study expands knowledge of the myeloma cell contact-induced signature in the stromal compartment of myelomatous bones and thus offers potential targets that may allow detection and treatment of myeloma bone disease at an early stage.
Normal human brain development is dependent on highly dynamic epigenetic processes for spatial and temporal gene regulation. Recent work identified wide-spread changes in DNA methylation during fetal brain development. We profiled CpG methylation in frontal cortex of 27 fetuses from gestational weeks 12-42, using Illumina 450K methylation arrays. Sites showing genome-wide significant correlation with gestational age were compared to a publicly available data set from gestational weeks 3-26. Altogether, we identified 2016 matching developmentally regulated differentially methylated positions (m-dDMPs): 1767 m-dDMPs were hypermethylated and 1149 hypomethylated during fetal development. M-dDMPs are underrepresented in CpG islands and gene promoters, and enriched in gene bodies. They appear to cluster in certain chromosome regions. M-dDMPs are significantly enriched in autism-associated genes and CpGs. Our results promote the idea that reduced methylation dynamics during fetal brain development may predispose to autism. In addition, m-dDMPs are enriched in genes with human-specific brain expression patterns and/or histone modifications. Collectively, we defined a subset of dDMPs exhibiting constant methylation changes from early to late pregnancy. The same epigenetic mechanisms involving methylation changes in cis-regulatory regions may have been adopted for human brain evolution and ontogeny.
Background: There is increasing evidence that glial cells play a role in the pathomechanisms of mood disorders and the mode of action of antidepressant drugs.
Methods: To examine whether there is a direct effect on the expression of different genes encoding proteins that have been implicated in the pathophysiology of affective disorders, primary astrocyte cell cultures from rats were treated with two different antidepressant drugs, imipramine and escitalopram, and the RNA expression of brain-derived neurotrophic factor (Bdnf), serotonin transporter (5Htt), dopamine transporter (Dat), and endothelial nitric oxide synthase (Nos3) was examined.
Results: Stimulation of astroglial cell culture with imipramine, a tricyclic antidepressant, led to a significant increase of the Bdnf RNA level whereas treatment with escitalopram did not. In contrast, 5Htt was not differentially expressed after antidepressant treatment. Finally, neither Dat nor Nos3 RNA expression was detected in cultured astrocytes.
Conclusion: These data provide further evidence for a role of astroglial cells in the molecular mechanisms of action of antidepressants.
Measles Virus Glycoprotein-Based Lentiviral Targeting Vectors That Avoid Neutralizing Antibodies
(2012)
Lentiviral vectors (LVs) are potent gene transfer vehicles frequently applied in research and recently also in clinical trials. Retargeting LV entry to cell types of interest is a key issue to improve gene transfer safety and efficacy. Recently, we have developed a targeting method for LVs by incorporating engineered measles virus (MV) glycoproteins, the hemagglutinin (H), responsible for receptor recognition, and the fusion protein into their envelope. The H protein displays a single-chain antibody (scFv) specific for the target receptor and is ablated for recognition of the MV receptors CD46 and SLAM by point mutations in its ectodomain. A potential hindrance to systemic administration in humans is pre-existing MV-specific immunity due to vaccination or natural infection. We compared transduction of targeting vectors and non-targeting vectors pseudotyped with MV glycoproteins unmodified in their ectodomains (MV-LV) in presence of \(\alpha\)-MV antibody-positive human plasma. At plasma dilution 1: 160 MV-LV was almost completely neutralized, whereas targeting vectors showed relative transduction efficiencies from 60% to 90%. Furthermore, at plasma dilution 1: 80 an at least 4-times higher multiplicity of infection (MOI) of MV-LV had to be applied to obtain similar transduction efficiencies as with targeting vectors. Also when the vectors were normalized to their p24 values, targeting vectors showed partial protection against \(\alpha\)-MV antibodies in human plasma. Furthermore, the monoclonal neutralizing antibody K71 with a putative epitope close to the receptor binding sites of H, did not neutralize the targeting vectors, but did neutralize MV-LV. The observed escape from neutralization may be due to the point mutations in the H ectodomain that might have destroyed antibody binding sites. Furthermore, scFv mediated cell entry via the target receptor may proceed in presence of a-MV antibodies interfering with entry via the natural MV receptors. These results are promising for in vivo applications of targeting vectors in humans.
Predominant polarity in bipolar disorder and validation of the polarity index in a German sample
(2014)
Background: A large number of patients with bipolar disorder (BD) can be characterized by predominant polarity (PP), which has important implications for relapse prevention. Recently, Popovic et al. (EUR NEUROPSYCHOPHARM 22(5): 339–346, 2012) proposed the Polarity Index (PI) as a helpful tool in the maintenance treatment of BD. As a numeric expression, it reflects the efficacy of drugs used in treatment of BD. In the present retrospective study, we aimed to validate this Index in a large and well characterized German bipolar sample.
Methods: We investigated 336 bipolar patients (BP) according to their PP and calculated the PI for each patient in order to prove if maintenance treatment differs according to their PP. Furthermore, we analysed whether PP is associated with demographic and clinical characteristics of BP.
Results: In our sample, 63.9% of patients fulfilled criteria of PP: 169 patients were classified as depressive predominant polarity (DPP), 46 patients as manic predominant polarity (MPP). The two groups differed significantly in their drug regime: Patients with DPP were more often medicated with lamotrigine and antidepressants, patients with MPP were more often treated with lithium, valproate, carbamazepine and first generation antipsychotics.
However, patients with DPP and MPP did not differ significantly with respect to the PI, although they received evidence-based and guideline-driven treatment.
Conclusion: The reason for this negative finding might well be that for several drugs, which were used frequently, no PI value is available. Nevertheless we suggest PP as an important concept in the planning of BD maintenance treatment.
Major depressive disorder and the anxiety disorders are highly prevalent, disabling and moderately heritable. Depression and anxiety are also highly comorbid and have a strong genetic correlation (r(g) approximate to 1). Cognitive behavioural therapy is a leading evidence-based treatment but has variable outcomes. Currently, there are no strong predictors of outcome. Therapygenetics research aims to identify genetic predictors of prognosis following therapy. We performed genome-wide association meta-analyses of symptoms following cognitive behavioural therapy in adults with anxiety disorders (n = 972), adults with major depressive disorder (n = 832) and children with anxiety disorders (n = 920; meta-analysis n = 2724). We (h(SNP)(2)) and polygenic scoring was used to examine genetic associations between therapy outcomes and psychopathology, personality and estimated the variance in therapy outcomes that could be explained by common genetic variants learning. No single nucleotide polymorphisms were strongly associated with treatment outcomes. No significant estimate of h(SNP)(2) could be obtained, suggesting the heritability of therapy outcome is smaller than our analysis was powered to detect. Polygenic scoring failed to detect genetic overlap between therapy outcome and psychopathology, personality or learning. This study is the largest therapygenetics study to date. Results are consistent with previous, similarly powered genome-wide association studies of complex traits.
Molecular-based subclassifications of breast cancer are important for identifying treatment options and stratifying the prognosis in breast cancer. This study aimed to assess the prognosis relative to disease-free survival (DFS) and overall survival (OS) in patients with triple-negative breast cancer (TNBC) and other subtypes, using a biomarker panel including cytokeratin 5 (CK5), cluster of differentiation 117 (CD117), and epidermal growth factor receptor (EGFR). This cohort–case study included histologically confirmed breast carcinomas as cohort arm. From a total of 894 patients, 572 patients with early breast cancer, sufficient clinical data, and archived tumor tissue were included. Using the immunohistochemical markers CK5, CD117, and EGFR, two subgroups were formed: one with all three biomarkers negative (TBN) and one with at least one of those three biomarkers positive (non-TBN). There were significant differences between the two biomarker subgroups (TBN versus non-TBN) in TNBC for DFS (p = 0.04) and OS (p = 0.02), with higher survival rates (DFS and OS) in the non-TBN subgroup. In this study, we found the non-TBN subgroup of TNBC lesions with at least one positive biomarker of CK5, CD117, and/or EGFR, to be associated with longer DFS and OS.
Background
The efficacy of parent-child training (PCT) regarding child symptoms may be reduced if the mother has attention-deficit/hyperactivity disorder (ADHD). The AIMAC study (ADHD in Mothers and Children) aimed to compensate for the deteriorating effect of parental psychopathology by treating the mother (Step 1) before the beginning of PCT (Step 2). This secondary analysis was particularly concerned with the additional effect of the Step 2 PCT on child symptoms after the Step 1 treatment.
Methods
The analysis included 143 mothers and children (aged 6–12 years) both diagnosed with ADHD. The study design was a two-stage, two-arm parallel group trial (Step 1 treatment group [TG]: intensive treatment of the mother including psychotherapy and pharmacotherapy; Step 1 control group [CG]: supportive counseling only for mother; Step 2 TG and CG: PCT). Single- and multi-group analyses with piecewise linear latent growth curve models were applied to test for the effects of group and phase. Child symptoms (e.g., ADHD symptoms, disruptive behavior) were rated by three informants (blinded clinician, mother, teacher).
Results
Children in the TG showed a stronger improvement of their disruptive behavior as rated by mothers than those in the CG during Step 1 (Step 1: TG vs. CG). In the CG, according to reports of the blinded clinician and the mother, the reduction of children’s disruptive behavior was stronger during Step 2 than during Step 1 (CG: Step 1 vs. Step 2). In the TG, improvement of child outcome did not differ across treatment steps (TG: Step 1 vs. Step 2).
Conclusions
Intensive treatment of the mother including pharmacotherapy and psychotherapy may have small positive effects on the child’s disruptive behavior. PCT may be a valid treatment option for children with ADHD regarding disruptive behavior, even if mothers are not intensively treated beforehand.
Trial registration
ISRCTN registry ISRCTN73911400. Registered 29 March 2007.
Die quantitative Analyse der relativen DNA-Methylierung gilt als eine der vielversprechendsten Methoden der molekularen Altersschätzung. Viele Studien der letzten Jahre identifizierten geeignete Positionen im Genom, deren DNA-Methylierung sich altersabhängig verändert. Für den Einsatz dieser Methode in der Routine- bzw. Fallarbeit ist es von großer Bedeutung, angewandte Analysetechniken zu validieren. Als ein Teilaspekt dieser Validierung sollte die Vergleichbarkeit der Analyseergebnisse zur DNA-Methylierung mithilfe der Mini- und Pyrosequenzierung zwischen verschiedenen Laboren evaluiert werden. Die Arbeitsgruppe „Molekulare Altersschätzung“ der Deutschen Gesellschaft für Rechtsmedizin (DGRM) führte hierzu den ersten, technischen Ringversuch durch, der 4 Positionen in den Genen PDE4C, EDARADD, SST und KLF14 umfasste. Diese Marker waren in vorangegangenen Studien als altersabhängige Biomarker charakterisiert worden. Am Ringversuch nahmen 12 Labore teil, wobei jedes die Wahl zwischen der Minisequenzierung und/oder der Pyrosequenzierung für die quantitative Methylierungsanalyse hatte. Jedem teilnehmenden Labor wurden Blut- und Speichelproben von 3 Personen unterschiedlichen Alters übersandt. Die Wahl der Reagenzien für die Probenbearbeitung wurde den Teilnehmern freigestellt.
Die Ergebnisse der Minisequenzierung zeigten systematische Abweichungen zwischen den Laboren, die am ehesten auf die Verwendung unterschiedlicher Reagenzien und Analyseplattformen zurückzuführen sein können. Die Resultate der Pyrosequenzierung hingegen wiesen nicht auf systematische Abweichungen zwischen den Laboren hin, hier zeigte sich jedoch die Tendenz einer markerabhängigen Abweichung. Darüber hinaus konnten Unterschiede hinsichtlich technischer Probleme zwischen Laboren mit mehr Erfahrung in der jeweiligen Sequenzierungsmethode und Laboren mit weniger Erfahrung festgestellt werden. Sowohl die Beobachtung von systematischen als auch die von markerabhängigen Abweichungen lässt den Schluss zu, dass eine Übertragung von Analysemethoden zwischen Laboren grundsätzlich möglich ist, eine Anpassung des jeweiligen Modells zur Altersschätzung jedoch notwendig sein kann.
Background
Several recent studies have investigated the role of C-reactive protein (CRP) in bipolar disorder (BD), but few studies have directly investigated the interaction between CRP genetic variants and peripheral CRP concentration across different phases of BD. In this study, we aimed to replicate previous findings that demonstrated altered CRP levels in BD, and to investigate whether there is an association of peripheral protein expression with genetic variants in the CRP gene.
Methods
221 patients were included in the study, of which 183 (all episodes, 46 not medicated, 174 medicated) were genotyped for CRP single-nucleotide polymorphisms (SNPs) shown to influence peripheral CRP protein expression (rs1800947, rs2808630, rs1417938, rs1205).
Results
There were no differences in CRP levels associated with the genotypes, only regarding the rs1205 SNP there were significantly different CRP protein expression between the genotypes when taking body mass index, age, BD polarity, subtype and leukocyte number into account. However, we could show significantly elevated CRP protein expression in manic patients compared to euthymic and depressed patients, independent from genotype. Medication was found to have no effect on CRP protein expression.
Conclusions
These results indicate that low grade inflammation might play a role in mania and might be rather a state than a trait marker of bipolar disorder.