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Sonstige beteiligte Institutionen
- Center for Interdisciplinary Clinical Research, Würzburg University, Würzburg, Germany (1)
- Department of Paediatric Radiology, Institute of Diagnostic and Interventional Radiology, Josef-Schneider-Straße 2, Wuerzburg 97080, Germany (1)
- IZKF Nachwuchsgruppe Geweberegeneration für muskuloskelettale Erkrankungen (1)
- Lehrstuhl für Regeneration Muskuloskelettaler Gewebe (1)
- Muskuloskelettales Centrum Würzburg (MCW) (1)
„Black esophagus“ oder „akute Ösophagusnekrose“ (AÖN) ist eine seltene Erkrankung, die sich makroskopisch durch eine zirkumferente Schwarzverfärbung der Ösophagusmukosa mit abruptem Ende am gastroösophagealen Übergang auszeichnet. Die genaue Pathogenese ist unbekannt; es werden multifaktorielle Einflüsse wie z. B. Säurereflux, Ischämie und verringerte Schutzmechanismen der Mukosa als mögliche Ursachen diskutiert.
Vorgestellt werden 2 Obduktionsfälle, die typische Befunde einer AÖN aufwiesen. Zusätzlich hatten Fall 1 eine Candida-Infektion und Fall 2 eine Appendizitis, sodass eine infektiöse Genese in beiden Fällen eine Rolle gespielt haben könnte.
In der vorliegenden Arbeit wurde das Vorkommen neu erworbener N-Glykosylierungsmotive in t(14;18)-positiven und -negativen FL der lokalisierten (FL I/II) und fortgeschrittenen Stadien (FL III/IV), sowie zum Zeitpunkt der Primärdiagnose und des Rezidivs untersucht. Dabei wurde der jeweilige Haupttumorklon mit Hilfe von „Next Generation Sequencing“ und unter Verwendung des „LymphoTrack® Assays“ in einer Serie von 68 kryoasservierten FL identifiziert 36 t(14;18)-negative und 32 t(14;18)-positive FL. Die Frequenz neu erworbener N-Glykosylierungsmotive unterschied sich signifikant zwischen t(14;18)-positiven und -negativen PD/R-FL III/IV, während man zwischen t(14;18)-positiven und -negativen PD/R-FL I/II keinen Unterschied beobachten konnte. Des Weiteren zeigten t(14;18)-negative PD/R-FL I-IV im Vergleich zu t(14;18)-positiven PD/R-FL I-IV signifikant häufiger einen Zugewinn neuer N-Glykosylierungsmotive in der FR3 Region des BCL2 Gens, sowie eine vermehrte Nutzung des IGHV4-34 Keimbahngens. Interessanterweise beschränkte sich die Nutzung des IGHV4-34 Gens auf PD-FL und konnte in R-FL nicht nachgewiesen werden. Da sowohl das Vorkommen neu erworbener N-Glykosylierungsmotive in FR3 als auch die Nutzung von IGHV4-34 im Zusammenhang mit Autoimmunerkrankungen beschrieben wurden, deuten unsere Ergebnisse darauf hin, dass die Subgruppe der t(14;18)-negativen FL im pathologischen Prozess der Onkogenese mehr auf die Stimulation durch (Auto)-Antigene als durch die Stimulation des B-Zell Rezeptors mit Lektinen (DC-SIGN) angewiesen sein könnte.
(1) Background: C-X-C Motif Chemokine Receptor 4 (CXCR4) and Fibroblast Activation Protein Alpha (FAP) are promising theranostic targets. However, it is unclear whether CXCR4 and FAP positivity mark distinct microenvironments, especially in solid tumors. (2) Methods: Using Random Forest (RF) analysis, we searched for entity-independent mRNA and microRNA signatures related to CXCR4 and FAP overexpression in our pan-cancer cohort from The Cancer Genome Atlas (TCGA) database — representing n = 9242 specimens from 29 tumor entities. CXCR4- and FAP-positive samples were assessed via StringDB cluster analysis, EnrichR, Metascape, and Gene Set Enrichment Analysis (GSEA). Findings were validated via correlation analyses in n = 1541 tumor samples. TIMER2.0 analyzed the association of CXCR4 / FAP expression and infiltration levels of immune-related cells. (3) Results: We identified entity-independent CXCR4 and FAP gene signatures representative for the majority of solid cancers. While CXCR4 positivity marked an immune-related microenvironment, FAP overexpression highlighted an angiogenesis-associated niche. TIMER2.0 analysis confirmed characteristic infiltration levels of CD8+ cells for CXCR4-positive tumors and endothelial cells for FAP-positive tumors. (4) Conclusions: CXCR4- and FAP-directed PET imaging could provide a non-invasive decision aid for entity-agnostic treatment of microenvironment in solid malignancies. Moreover, this machine learning workflow can easily be transferred towards other theranostic targets.
Allogenic hematopoietic stem cell transplantation (allo-HCT) is a curative therapy for the treatment of malignant and non-malignant bone marrow diseases. The major complication of this treatment is a highly inflammatory reaction known as Graft-versus-Host Disease (GvHD). Cyclosporin A (CsA) and tacrolimus are used to treat GvHD which limits inflammation but also interferes with the anticipated Graft-versus-Leukemia (GvL) effect. These drugs repress conventional T cells (Tcon) along with regulatory T cells (Treg), which are important for both limiting GvHD and supporting GvL. Both of these drugs inhibit calcineurin (CN), which dephosphorylates and activates the nuclear factor of activated T-cells (NFAT) family of transcription factors. Here, we make use of our Cd4cre.Cas9+ mice and developed a highly efficient non-viral CRISPR/Cas9 gene editing method by gRNA-only nucleofection. Utilizing this technique, we demonstrated that unstimulated mouse T cells upon NFATc1 or NFATc2 ablation ameliorated GvHD in a major mismatch mouse model. However, in vitro pre-stimulated mouse T cells could not achieve long-term protection from GvHD upon NFAT single-deficiency. This highlights the necessity of gene editing and transferring unstimulated human T cells during allo-HCT. Indeed, we established a highly efficient ribonucleoprotein (RNP)-mediated CRISPR/Cas9 gene editing for NFATC1 and/or NFATC2 in pre-stimulated as well as unstimulated primary human T cells. In contrast to mouse T cells, not NFATC1 but NFATC2 deficiency in human T cells predominantly affected proinflammatory cytokine production. However, either NFAT single-knockout kept cytotoxicity of human CD3+ T cells untouched against tumor cells in vitro. Furthermore, mouse and human Treg were unaffected upon the loss of a single NFAT member. Lastly, NFATC1 or NFATC2-deficient anti-CD19 CAR T cells, generated with our non-viral ‘one-step nucleofection’ method validated our observations in mouse and human T cells. Proinflammatory cytokine production was majorly dependent on NFATC2 expression, whereas, in vitro cytotoxicity against CD19+ tumor cells was undisturbed in the absence of either of the NFAT members. Our findings emphasize that NFAT single-deficiency in donor T cells is superior to CN-inhibitors as therapy during allo-HCT to prevent GvHD while preserving GvL in patients.
Active vitamin D (1,25(OH)2D3) is known to exert direct anti-cancer actions on various malignant tissues through binding to the vitamin D receptor (VDR). These effects have been demonstrated in breast, prostate, renal and thyroid cancers, which all have a high propensity to metastasise to bone. In addition, there is evidence that vitamin D catabolism via 24-hydroxylase (CYP24A1) is altered in tumour cells, thus, reducing local active vitamin D levels in cancer cells. The aim of this study was to assess VDR and CYP24A1 expression in various types of bone metastases by using immunohistochemistry. Overall, a high total VDR protein expression was detected in 59% of cases (39/66). There was a non-significant trend of high-grade tumours towards the low nuclear VDR expression (p = 0.07). Notably, patients with further distant metastases had a reduced nuclear VDR expression (p = 0.03). Furthermore, a high CYP24A1 expression was detected in 59% (39/66) of bone metastases. There was a significant positive correlation between nuclear VDR and CYP24A1 expression (p = 0.001). Collectively, the VDR and CYP24A1 were widely expressed in a multitude of bone metastases, pointing to a potential role of vitamin D signalling in cancer progression. This is of high clinical relevance, as vitamin D deficiency is frequent in patients with bone metastases.
Machine-Learning-Based Identification of Tumor Entities, Tumor Subgroups, and Therapy Options
(2023)
Molecular genetic analyses, such as mutation analyses, are becoming increasingly important in the tumor field, especially in the context of therapy stratification. The identification of the underlying tumor entity is crucial, but can sometimes be difficult, for example in the case of metastases or the so-called Cancer of Unknown Primary (CUP) syndrome. In recent years, methylome and transcriptome utilizing machine learning (ML) approaches have been developed to enable fast and reliable tumor and tumor subtype identification. However, so far only methylome analysis have become widely used in routine diagnostics.
The present work addresses the utility of publicly available RNA-sequencing data to determine the underlying tumor entity, possible subgroups, and potential therapy options. Identification of these by ML - in particular random forest (RF) models - was the first task. The results with test accuracies of up to 99% provided new, previously unknown insights into the trained models and the corresponding entity prediction. Reducing the input data to the top 100 mRNA transcripts resulted in a minimal loss of prediction quality and could potentially enable application in clinical or real-world settings.
By introducing the ratios of these top 100 genes to each other as a new database for RF models, a novel method was developed enabling the use of trained RF models on data from other sources.
Further analysis of the transcriptomic differences of metastatic samples by visual clustering showed that there were no differences specific for the site of metastasis. Similarly, no distinct clusters were detectable when investigating primary tumors and metastases of cutaneous skin melanoma (SKCM).
Subsequently, more than half of the validation datasets had a prediction accuracy of at least 80%, with many datasets even achieving a prediction accuracy of – or close to – 100%.
To investigate the applicability of the used methods for subgroup identification, the TCGA-KIPAN dataset, consisting of the three major kidney cancer subgroups, was used. The results revealed a new, previously unknown subgroup consisting of all histopathological groups with clinically relevant characteristics, such as significantly different survival. Based on significant differences in gene expression, potential therapeutic options of the identified subgroup could be proposed.
Concludingly, in exploring the potential applicability of RNA-sequencing data as a basis for therapy prediction, it was shown that this type of data is suitable to predict entities as well as subgroups with high accuracy. Clinical relevance was also demonstrated for a novel subgroup in renal cell carcinoma. The reduction of the number of genes required for entity prediction to 100 genes, enables panel sequencing and thus demonstrates potential applicability in a real-life setting.
Background: Primary cutaneous follicular B-cell lymphoma (PCFBCL) represents an indolent subtype of Non-Hodgkin’s lymphomas, being clinically characterized by slowly growing tumors of the skin and common cutaneous relapses, while only exhibiting a low propensity for systemic dissemination or fatal outcome. Up to now, only few studies have investigated underlying molecular alterations of PCFBCL with respect to somatic mutations. Objectives: Our aim was to gain deeper insight into the pathogenesis of PCFBCL and to delineate discriminatory molecular features of this lymphoma subtype. Methods: We performed hybridization-based panel sequencing of 40 lymphoma-associated genes of 10 cases of well-characterized PCFBCL. In addition, we included two further ambiguous cases of atypical B-cell-rich lymphoid infiltrate/B-cell lymphoma of the skin for which definite subtype attribution had not been possible by routine investigations. Results: In 10 out of 12 analyzed cases, we identified genetic alterations within 15 of the selected 40 target genes. The most frequently detected alterations in PCFBCL affected the TNFRSF14, CREBBP, STAT6 and TP53 genes. Our analysis unrevealed novel mutations of the BCL2 gene in PCFBCL. All patients exhibited an indolent clinical course. Both the included arbitrary cases of atypical B-cell-rich cutaneous infiltrates showed somatic mutations within the FAS gene. As these mutations have previously been designated as subtype-specific recurrent alterations in primary cutaneous marginal zone lymphoma (PCMZL), we finally favored the diagnosis of PCMZL in these two cases based on these molecular findings. Conclusions: To conclude, our molecular data support that PCFBCL shows distinct somatic mutations which may aid to differentiate PCFBCL from pseudo-lymphoma as well as from other indolent and aggressive cutaneous B-cell lymphomas. While the detected genetic alterations of PCFBCL did not turn out to harbor any prognostic value in our cohort, our molecular data may add adjunctive discriminatory features for diagnostic purposes on a molecular level.
(1) Background: molecular tumor boards (MTBs) are crucial instruments for discussing and allocating targeted therapies to suitable cancer patients based on genetic findings. Currently, limited evidence is available regarding the regional impact and the outreach component of MTBs; (2) Methods: we analyzed MTB patient data from four neighboring Bavarian tertiary care oncology centers in Würzburg, Erlangen, Regensburg, and Augsburg, together constituting the WERA Alliance. Absolute patient numbers and regional distribution across the WERA-wide catchment area were weighted with local population densities; (3) Results: the highest MTB patient numbers were found close to the four cancer centers. However, peaks in absolute patient numbers were also detected in more distant and rural areas. Moreover, weighting absolute numbers with local population density allowed for identifying so-called white spots—regions within our catchment that were relatively underrepresented in WERA MTBs; (4) Conclusions: investigating patient data from four neighboring cancer centers, we comprehensively assessed the regional impact of our MTBs. The results confirmed the success of existing collaborative structures with our regional partners. Additionally, our results help identifying potential white spots in providing precision oncology and help establishing a joint WERA-wide outreach strategy.
NFATc3 in der akuten GvHD
(2023)
Bei Leukämien, Lymphomen und dem Multiplen Myelom stellt die allogene hämatopoetische Stammzelltransplantation (allo-HCT) oft die letzte kurative Therapieoption dar. Spender-T-Zellen (v.a. CD8+-T-Zellen), die im Transplantat enthalten sind, erkennen nach Chemo-/Strahlentherapie verbliebene Reste des entarteten Empfängergewebes, eradizieren dieses und verhindern somit ein Tumorrezidiv (Graft-versus-Leukämie Reaktion/GvL). Häufig attackieren Spender-T-Zellen (v.a. CD4+-Th1-Zellen) aber auch nicht-malignes Gewebe (z.B. Haut, Leber und Darm), was bis zum Tod des Patienten führen kann (Graft-versus-Host Disease/GvHD). Calcineurin-Inhibitoren wie Cyclosporin A (CsA) und Tacrolimus, die oft schon prophylaktisch verabreicht werden, verhindern über eine unselektive Inhibition aller Mitglieder der NFAT-Transkriptionsfaktorfamilie (Nuclear factor of activated T-cells) die Aktivierung der Spender-T-Zellen. Es folgt eine klinische Besserung der GvHD-Symptomatik, während jedoch der GvL-Effekt ebenfalls supprimiert wird. Bisherige Untersuchungen unserer Arbeitsgruppe am Mausmodell hatten gezeigt, dass die selektive Inhibition eines NFAT-Familienmitgliedes (NFATc1 oder NFATc2) in den Donor-T-Zellen zu einer signifikanten Besserung der aGvHD bei jedoch erhaltener GvL führt. Es wurde nun der Einfluss des dritten, in Lymphozyten exprimierten NFAT-Mitglieds NFATc3 im Kontext der aGvHD untersucht.
Zur Basisanalyse der neu kreierten Nfatc3fl/fl.Cd4cre- und Nfatc1fl/fl.Nfatc3fl/fl.Cd4cre-Mauslinien erfolgten durchflusszytometrische und Western-Blot-Analysen. Anschließend wurden In-vivo-Untersuchungen unter Verwendung eines etablierten major-mismatch-aGvHD-Modells (H-2b→H-2d) durchgeführt.
Es konnte gezeigt werden, dass durch eine NFATc3- (+/- NFATc1-) Defizienz direkt ex vivo die CD4+/CD8+-Ratio durch Abnahme der CD4+- hin zu den CD8+-T-Zellen verschoben wird. Auch zeigte sich in den entsprechenden Genotypen eine Abnahme der naiven- und dafür vice versa eine Zunahme der Effektor-T-Zellen. In den wiederholt durchgeführten aGvHD-Versuchen zeigte sich in vivo als Korrelat der (ebenfalls erneut nachgewiesenen) Abnahme des CD4+/CD8+-Quotienten in den Zielorganen eine geringere Expansion der NFAT-defizienten als der wildtypischen T-Zellen. Leider spiegelte sich dies nicht in dem clinical score zur Quantifizierung der aGvHD-Symptomatik wider. Auch das Körpergewicht der Versuchsgruppe nahm rapide ab. Ursächlich hierfür ist – als Korrelat zur direkt ex vivo nachgewiesenen Aktivierungsneigung – ein vermehrter Th1-Shift der NFATc3 (+/-NFATc1-) defizienten T-Zellen.
Eine Inhibierung von NFATc3 – im Gegensatz zu NFATc1 und NFATc2 – ist demzufolge kein sinnvoller Ansatzpunkt für eine mögliche, zielgerichtetere aGvHD-Therapie. Der positive Effekt der reduzierten Proliferationsneigung der NFATc3-defizienten Lymphozyten wird durch deren vermehrte Aktivierungsneigung mit erhöhter Sekretion von pro-inflammatorischen Zytokinen zunichte gemacht.
Glioblastoma leads to a fatal course within two years in more than two thirds of patients. An essential cornerstone of therapy is chemotherapy with temozolomide (TMZ). The effect of TMZ is counteracted by the cellular repair enzyme O\(^6\)-methylguanine-DNA methyltransferase (MGMT). The MGMT promoter methylation, the main regulator of MGMT expression, can change from primary tumor to recurrence, and TMZ may play a significant role in this process. To identify the potential mechanisms involved, three primary stem-like cell lines (one astrocytoma with the mutation of the isocitrate dehydrogenase (IDH), CNS WHO grade 4 (HGA)), and two glioblastoma (IDH-wildtype, CNS WHO grade 4) were treated with TMZ. The MGMT promoter methylation, migration, proliferation, and TMZ-response of the tumor cells were examined at different time points. The strong effects of TMZ treatment on the MGMT methylated cells were observed. Furthermore, TMZ led to a loss of the MGMT promoter hypermethylation and induced migratory rather than proliferative behavior. Cells with the unmethylated MGMT promoter showed more aggressive behavior after treatment, while HGA cells reacted heterogenously. Our study provides further evidence to consider the potential adverse effects of TMZ chemotherapy and a rationale for investigating potential relationships between TMZ treatment and change in the MGMT promoter methylation during relapse.