Genome-wide gene expression analysis of lasermicrodissected L&H cells: histogenetic origin and pathogenesis of nodular lymphocyte-predominant Hodgkin lymphoma

Das Hodgkin-Lymphom (HL), eines der häufigsten malignen Lymphome, umfasst zwei Entitäten, das klassische HL (cHL) und das noduläre lymphozyten-prädominante HL (NLPHL). Die Tumorzellen – Hodgkin-Reed/Sternberg (HRS) Zellen des cHL und die „lymphocytic & histiocytic“ (L&H) Zellen des NLPHL – repräsentieren üblicherweise weni-ger als 1% der Zellen im Tumor, verstreut in einem inflammatorischen zellulären Hinter-grund. Die Tumorzellen beider Entitäten stammen von Keimzentrums-(GC)-B-Zellen ab, sind aber genetisch, morphologisch und phänotypisch unterschiedlich. Die Pathogenese des NLPHL und seine Verwandtschaft zu anderen Lymphomen sind weitestgehend unbe-kannt. Dies liegt zum Teil in der technischen Herausforderung begründet, diese seltenen neoplastischen L&H-Zellen zu analysieren und daher ist bislang keine systematische Gen-expressionsstudie von L&H-Zellen im großen Rahmen durchgeführt worden. In der vorliegenden Arbeit konnte eine verlässliche Methode zur Lasermikrodissektion primärer L&H-Zellen aus Gefrierschnitten, die RNA-Isolation aus diesen Zellen und die Analyse ihrer globalen Genexpression nach einer 2-Runden in vitro Transkription im Ver-gleich zu normalen und anderen malignen B-Zellen erfolgreich etabliert werden. Diese genomweite Expressionsanalyse ergab wichtige neue Einsichten in die Natur und Patho-genese von L&H-Zellen des NLPHL. Obwohl L&H-Zellen klar GC-B-Zellen in vielen phäno-typischen und genetischen Aspekten ähneln, scheint ihr Genexpressionsprofil sie am Ü-bergang von GC-B-Zellen zu Gedächtnis-B-Zellen zu platzieren. Mehrere pathogenetische Mechanismen konnten im NLPHL identifiziert werden, einschließlich der starken NF-κB-Aktivität und der Aktivierung des ERK-Signalweges. Die Aktivierung dieser Signalwege steht in Verbindung mit der Pathogenese vieler Krebserkrankungen. Ihre aberrante Akti-vierung in L&H-Zellen war bislang unbekannt und könnte von pathogener Relevanz sein und zu neuen therapeutischen Strategien führen. Weitere pathogenetische Mechanismen beinhalten die Unterdrückung von Apoptose und die Kreierung eines immunsupprimie-renden Mikromilieus um der Immunüberwachung zu entkommen. Die Rolle anderer Ge-ne, die sich als spezifisch in L&H-Zellen dereguliert erwiesen, muss noch weitergehend untersucht werden. Da HRS- und L&H-Zellen markante Unterschiede in immunhistoche-mischen Analysen zeigen, war ihre enge Verwandtschaft bezüglich ihres Genexpressi-onsprofils überraschend. Die Ähnlichkeiten dieser Tumorzellen schließen die konstitutive NF-κB-Aktivität und ERK-Signaltransduktion ein, was nahe legt, dass NLPHL und cHL ähnliche pathogenetische Mechanismen teilen. Die Genexpressionsprofile von HRS- und L&H-Zellen ähneln sich auch in Bezug auf die Runterregulation von B-Zellmarkern, ob-wohl dieses Ereignis in L&H-Zellen nicht so schwerwiegend wie in HRS-Zellen ist. L&H-Zellen zeigten bezüglich ihrer Genexpression sogar noch größere Ähnlichkeit zu TCRBL (und einer Untergruppe von DLBCL). Da die Unterscheidung von NLPHL und TCRBL je-doch klinisch wichtig ist, könnten die Gene, die zwischen L&H-Zellen und den Lymphom-zellen des TCRBL unterscheiden, wertvolle Marker für die Differentialdiagnose von NLPHL und TCRBL werden.Hodgkin lymphoma (HL), one of the most common malignant lymphomas, comprises two entities, classical HL (cHL) and nodular lymphocyte-predominant HL (NLPHL). The tumor cells - Hodgkin and Reed/Sternberg (HRS) cells in cHL and “lymphocytic and histiocytic” (L&H) cells in NLPHL - usually represent less than 1% of cells in the tumor, being dis-persed in a prominent inflammatory cellular background. Tumor cells of both entities are derived from germinal center (GC) B cells, but they are genetically, morphologically and phenotypically different. The pathogenesis of NLPHL and its relationship to other lym-phomas are largely unknown. This is partly due to the technical challenge of analyzing its rare neoplastic L&H cells and therefore, no systematic large-scale gene expression study of L&H cells has been performed so far. In the present study, a reliable method to lasermicrodissect primary L&H cells from fro-zen tissue sections, isolate RNA from the cells and analyse their global gene expression after a two-rounded in vitro transcription in comparison to normal and other malignant B cells was successfully established. This genome-wide expression analysis revealed impor-tant novel insights into the nature and pathogenesis of the L&H cells in NLPHL. Although L&H cells clearly resemble GC B cells in many phenotypic and genetic aspects, their gene expression profile seems to place them at the transition of GC B cells to memory B cells. Several pathogenetic mechanisms were identified in NLPHL, including strong constitutive activity of NF-κB and activation of the ERK signaling pathway. Activation of these path-ways has been implicated in the pathogenesis of several cancers. Their aberrant activa-tion in L&H cells was previously unknown and might be of pathogenic relevance and could lead to novel therapeutic strategies. Further pathogenetic mechanisms in NLPHL involve the suppression of apoptosis and the creation of an immunosuppressive environ-ment to escape from immune surveillance. The role of other genes which emerged to be specifically deregulated in L&H cells requires to be further investigated. Since HRS and L&H cells show marked differences at immunohistochemical analysis, their close related-ness in terms of gene expression profile appears surprising. Similarities among these tumor cells include constitutive NF-κB activity and ERK signaling, which suggest NLPHL and cHL may share similar pathogenetic mechanisms. The gene expression profile of HRS and L&H cells also resemble each another because of downregulation of B lineage-specific genes, although this event is not as severe in L&H cells as in HRS cells. L&H cells turned out to be even more similar to TCRBL (and a subset of DLBCL) in terms of gene expres-sion. As the distinction between NLPHL and TCRBL is, however, clinically important, the genes discriminating between L&H cells and TCRBL identified here may become valuable markers for the differential diagnosis of NLPHL and TCRBL

Origin and pathogenesis of nodular lymphocyte–predominant Hodgkin lymphoma as revealed by global gene expression analysis

The pathogenesis of nodular lymphocyte–predominant Hodgkin lymphoma (NLPHL) and its relationship to other lymphomas are largely unknown. This is partly because of the technical challenge of analyzing its rare neoplastic lymphocytic and histiocytic (L&H) cells, which are dispersed in an abundant nonneoplastic cellular microenvironment. We performed a genome-wide expression study of microdissected L&H lymphoma cells in comparison to normal and other malignant B cells that indicated a relationship of L&H cells to and/or that they originate from germinal center B cells at the transition to memory B cells. L&H cells show a surprisingly high similarity to the tumor cells of T cell–rich B cell lymphoma and classical Hodgkin lymphoma, a partial loss of their B cell phenotype, and deregulation of many apoptosis regulators and putative oncogenes. Importantly, L&H cells are characterized by constitutive nuclear factor {kappa}B activity and aberrant extracellular signal-regulated kinase signaling. Thus, these findings shed new light on the nature of L&H cells, reveal several novel pathogenetic mechanisms in NLPHL, and may help in differential diagnosis and lead to novel therapeutic strategies

Origin and pathogenesis of nodular lymphocyte–predominant Hodgkin lymphoma as revealed by global gene expression analysis

The pathogenesis of nodular lymphocyte–predominant Hodgkin lymphoma (NLPHL) and its relationship to other lymphomas are largely unknown. This is partly because of the technical challenge of analyzing its rare neoplastic lymphocytic and histiocytic (L&H) cells, which are dispersed in an abundant nonneoplastic cellular microenvironment. We performed a genome-wide expression study of microdissected L&H lymphoma cells in comparison to normal and other malignant B cells that indicated a relationship of L&H cells to and/or that they originate from germinal center B cells at the transition to memory B cells. L&H cells show a surprisingly high similarity to the tumor cells of T cell–rich B cell lymphoma and classical Hodgkin lymphoma, a partial loss of their B cell phenotype, and deregulation of many apoptosis regulators and putative oncogenes. Importantly, L&H cells are characterized by constitutive nuclear factor κB activity and aberrant extracellular signal-regulated kinase signaling. Thus, these findings shed new light on the nature of L&H cells, reveal several novel pathogenetic mechanisms in NLPHL, and may help in differential diagnosis and lead to novel therapeutic strategies

Mutations in the genes coding for the NF-κB regulating factors IκBα and A20 are uncommon in nodular lymphocyte-predominant Hodgkin’s lymphoma

Nodular lymphocyte-predominant Hodgkin’s lymphoma (NLPHL) shows constitutive NF-κB activity in the malignant lymphocyte-predominant (LP) cells. Constitutive NF-κB activity also plays a central pathogenetic role in classical Hodgkin’s lymphoma (cHL), where inactivating mutations in the NFKBIA and TNFAIP3 genes, coding for the negative NF-κB regulators IκBα and A20, respectively, contribute to NF-κB activation. To determine whether mutations in NFKBIA and TNFAIP3 are also involved in the pathogenesis of NLPHL these genes were sequenced from microdissected LP cells of 10 primary NLPHL. We also studied DEV, the only cell line proposedly derived from LP cells, after we had confirmed its derivation from NLPHL by gene expression analysis. A heterozygous somatic missense mutation in the NFKBIA gene was found in one NLPHL, and a heterozygous, possibly subclonal, two base pair insertion in TNFAIP3 in another case. The low mutation frequency and the absence of biallelic destructive mutations propose a minor contribution of NFKBIA and TNFAIP3 mutations to the NF-κB activity of NLPHL, suggesting different mechanisms of NF-κB activation in NLPHL and cHL

Analyzing primary Hodgkin and Reed-Sternberg cells to capture the molecular and cellular pathogenesis of classical Hodgkin lymphoma

The pathogenesis of classical Hodgkin lymphoma (cHL), the most common lymphoma in the young, is still enigmatic, largely because its Hodgkin and Reed-Sternberg (HRS) tumor cells are rare in the involved lymph node and therefore difficult to analyze. Here, by overcoming this technical challenge and performing, for the first time, a genome-wide transcriptional analysis of microdissected HRS cells compared with other B-cell lymphomas, cHL lines, and normal B-cell subsets, we show that they differ extensively from the usually studied cHL cell lines, that the lost B-cell identity of cHLs is not linked to the acquisition of a plasma cell-like gene expression program, and that Epstein-Barr virus infection of HRS cells has a minor transcriptional influence on the established cHL clone. Moreover, although cHL appears a distinct lymphoma entity overall, HRS cells of its histologic subtypes diverged in their similarity to other related lymphomas. Unexpectedly, we identified 2 molecular subgroups of cHL associated with differential strengths of the transcription factor activity of the NOTCH1, MYC, and IRF4 proto-oncogenes. Finally, HRS cells display deregulated expression of several genes potentially highly relevant to lymphoma pathogenesis, including silencing of the apoptosis-inducer BIK and of INPP5D, an inhibitor of the PI3K-driven oncogenic pathway. (Blood. 2012; 120(23):4609-4620

Are th...

We operationalize scientific output in a region by means of the number of articles (as in the SciSearch database) per year and technology output by means of the number of patent applications (as in the database of the European Patent Office) per priority year. All informetric analyses were done using the DIALOG online-system. The main research questions are the following: Which scientific and technological fields or topics are most influent within a region and which institutions or companies are mainly publishing articles or holding patents? Do the distributions of regional science and technology fields and of publishing institutions follow the well-known informetric function? Are there – as it is expected – only few fields and few institutions which dominate th

Querschnittskompetenzen im Lehramt – und darüber hinaus. Tagungsband zum Tag der Lehre und des Lernens 2022

Der "Tag der Lehre und des Lernens 2022" (TdL 2022) an der Pädagogischen Hochschule Freiburg, auf den sich diese Publikation bezieht, stand unter dem Thema "Querschnittskompetenzen im Lehramt – und darüber hinaus" und fand am 19.01.2022 live im Online-Format (Plenums- und Session-Videokonferenzen) statt. Die Wahl dieses Formats war zum einen bestimmt von der Überlegung, die Durchführung dieses Tages auch dann sicherzustellen, wenn die Coronaregelungen zum Zeitpunkt des Ereignisses keine größeren Zusammenkünfte in Präsenz erlauben. Zum anderen sollte durch die niederschwelligen Zugangsmöglichkeiten in einem Online-Setting größere Teilnehmer*innenzahlen als in den früheren Jahren erreicht werden. Die Veranstaltung war aus Sicht der Herausgebenden ein Erfolg. Insgesamt wurden von Lehrenden und Studierenden der Hochschule über 35 Sessions angeboten, mit einer Dauer von jeweils 45 bzw. 90 Minuten. Die Quantität der Angebote zeigt die Relevanz des Themas. Dadurch bedingt mussten allerdings viele Sessions parallel stattfinden, womit eine (Live-)Teilnahme an allen Angeboten leider nicht möglich war. Mit der vorliegenden Publikation soll nun die Gelegenheit geschaffen werden, (noch einmal, auf andere Weise oder auch erstmalig) Einblicke in die Vielfalt aller vorliegenden Konzepte, Forschungsergebnisse und Erkenntnisse aus offenen Diskussionsrunden zu unserem TdL-Schwerpunktthema "Querschnittskompetenzen im Lehramt – und darüber hinaus" zu erhalten. Die Beträge gliedern sich entlang der folgenden Kategorien: • Beiträge aus der Forschung • Beiträge aus der Praxis, inkl. Konzeptentwicklungen • Beiträge aus den offenen DiskussionsrundenDidactic Conference at the University of Education at Freiburg: "Day of Teaching and Learning 2022: Transversal Competencies in Teacher Education (and beyond)" Since the 2000s, school curricula as well as framework curricula for teacher education worldwide have increasingly called for a transformative, transversal and globally oriented educational policy and practice. Thus, relevant reference papers – for the Baden-Württemberg context, for example, the Framework Ordinance for Teacher Education of 2015 or the Education Plan for School Curricula of 2016 – also contain, in addition to subject-specific competence definitions, quite explicitly supra-disciplinary educational goals, which are identified as "guiding perspectives" (e.g. education for sustainable development, media education, etc.) or "transversal competencies". This novel set of educational requirements was the conceptual starting point for designing and organizing the 2022 edition of the University of Education at Freiburg's didactic conference "Day of Teaching and Learning". The publication at hand presents the gist of the conference's workshops and sessions, condensed in the individual written contributions of the participating authors. Its introductory chapter puts the developments in a broader, also international educational policy context, discusses different conceptual interpretations and asks about the conditions for success of a possible implementation of the educational policy recommendations in practice – in the field of teacher education and beyond