Primäre und sekundäre Lymphome des zentralen Nervensystems (ZNS), PCNSL und SCNSL, sind schwer behandelbar und mit einer ungünstigen Prognose assoziiert. Der ZNS-Tropismus dieser Lymphome hängt mit einer Dysregulation von Genen zusammen, die für Immunabwehr, Chemotaxis, Zellmigration und die Blut-Hirn-Schranke (BBB) relevant sind. Zur Untersuchung der molekularen Mechanismen wurde das Eμ-myc-Mausmodell genutzt, um die Faktoren zu analysieren, die zur ZNS-Tropie beitragen, insbesondere jene, die die BBB destabilisieren und die Immunantwort beeinflussen. Eμ-myc-Lymphome wurden in C57BL/6-Mäuse transplantiert und ZNS-positive von ZNS-negativen Lymphomen histologisch unterschieden. RNA-Sequenzierungen identifizierten Signalwege, die mit dem ZNS-Tropismus korreliert sind. Der NF-κB-Signalweg zeigte hierbei besondere Relevanz: Seine Hemmung in ZNS-positiven Lymphomen verringerte die ZNS-Tropie und stabilisierte die BBB durch den Erhalt der Tight-Junction-Proteine. Zudem ergab sich eine Hochregulation von Gfrα-1 in ZNS-positiven Lymphomen, was eine verstärkte Zellmigration zu hirn-konditioniertem Medium bewirkte. Durch die Aktivierung von Astrozyten und GDNF-Hochregulation wurde die BBB zusätzlich destabilisiert. ZNS-trope Lymphome induzierten Immunmodulationen benachbarter Zellen, wie Mikroglia und Astrozyten, und verstärkten den ZNS-Tropismus durch post-seneszente Signaturen. Das Zusammenspiel zwischen Lymphomzellen und Astrozyten, die Aktivierung der GDNF/Gfrα-1/RET-Signalachse und die BBB-Störung gelten als zentrale Mechanismen der ZNS-Tropie bei DLBCL-ähnlichen Lymphomen. Die gezielte Modulation dieser molekularen Pfade könnte die ZNS-Beteiligung bei aggressiven B-Zell-Lymphomen reduzieren. Weitere Untersuchungen könnten therapeutische Ansätze zur Minderung der ZNS-Tropie und Verbesserung der klinischen Ergebnisse bieten. / Primary and secondary CNS lymphomas (PCNSL and SCNSL) are difficult to treat, with a poor prognosis. CNS tropism in these lymphomas involves immune evasion, chemotaxis, cell migration, and blood-brain barrier (BBB) integrity. This study aimed to identify factors behind CNS tropism using the Eμ-myc mouse lymphoma model to compare CNS-tropic and non-tropic lymphomas. Methods: Eμ-myc lymphomas were transplanted into immunocompetent mice, classified as CNS (+) or CNS (-) by histology. RNA sequencing identified pathways linked to CNS tropism, focusing on NF-κB, which was suppressed using IκBα∆N in CNS (+) lymphomas in vitro and in vivo. BBB disruption was assessed through astrocyte activation and ZO-1 degradation, while BBB permeability was evaluated with the Evans Blue assay. Lymphoma migration towards GDNF-conditioned medium was tested via Boyden chambers, with GDNF/Gfrα-1/RET pathway involvement assessed by knockdown and RET inhibition. Immune modulation was analyzed by PD-L1 expression in astrocytes and microglia co-cultured with CNS lymphomas. Results: RNA sequencing showed upregulation of NF-κB targets, pro-inflammatory cytokines, and SASP in CNS (+) lymphomas. NF-κB inhibition prevented CNS tropism and preserved BBB integrity by blocking ZO-1 degradation. CNS (+) lymphomas displayed Gfrα-1 upregulation and migration toward brain-conditioned medium. Astrocyte activation and GDNF upregulation by CNS (+) lymphomas further impaired BBB stability. CNS (+) lymphomas induced immune modulation in neighboring astrocytes and microglia, with a post-senescence signature linked to CNS tropism. Interactions between lymphoma cells, astrocytes, the GDNF/Gfrα-1/RET axis, and BBB disruption are key to CNS tropism in DLBCL-like lymphomas. Targeting these pathways may help prevent CNS involvement in aggressive B-cell lymphomas, offering potential therapeutic avenues to improve patient outcomes.

Lymphomas are malignant tumours arising from cells in the lymphatic system. They are classified as B-cell lymphomas, T-cell lymphomas and Hodgkin lymphoma (HL). Of the B-cell lymphomas, one of the most common is diffuse large B-cell lymphoma (DLBCL). Many patients with lymphomas can be successfully treated however patients who relapse or are refractory have a poor prognosis, warranting further investigations to identify potential targets and develop novel drugs. Picropodophyllin (PPP), a potent and selective inhibitor of IGF-1R, inhibits malignant cell growth with low or no toxicity on normal cells in preclinical models. In paper I, we investigated the potential benefits of using PPP against DLBCL and found that the anti-tumor effects of PPP might possibly be explained by IGF-1R-unrelated mechanism(s). However, the inhibitory effects of PPP on lymphoma cells together with its low toxicity in vivo makes it a promising drug candidate for treatment. Melflufen, a derivative of melphalan, is currently being evaluated in a clinical phase I/II trial in relapsed or refractory multiple myeloma. In paper II, we confirmed previous reports of superior potency of melflufen over melphalan. Being active in cell lines and primary cultures of lymphoma cells as well as in a xenograft model in mice, melflufen considered being a candidate for further evaluation in treatment. bAP-15, a novel inhibitor of proteasome activity, inhibits ubiquitin specific peptidase 14 (USP14) and ubiquitin carboxyl-terminal hydrolase L5 (UCHL5). In paper III, we investigated the activity of b-AP15 in DLBCL and HL cell lines and compared the results to standard drugs used in treatment. Results showed inhibition of the proteasome and growth inhibition/cytotoxicity with IC50-values in the micromolar range. Treatment failure and lack of clinical benefit of proteasome inhibitors like bortezomib in DLBCL patients inspired us investigating for possible new targets, with major focus on proteasome inhibitors in DLBCL. In paper IV, we suggested that UCHL5 and/or USP14, as new targets for proteasome inhibitors in DLBCL, be further evaluated. The findings in this thesis suggest that PPP, Melflufen and b-AP15 are potential candidates for clinical drug development and UCHL5 and/or USP14 are new potential targets for proteasome inhibitors in DLBCL.

Le Lymphome à Cellules du Manteau (LCM) est une entité récemment identifiée qui se caractérise par la translocation génétique t(11 ;14)(q13 ;q32) et compte pour 2 à 10 % de tous les Lymphomes non-Hodgkiniens. Avec une survie médiane entre 3 et 5 ans après le diagnostic, le LCM est une pathologie agressive et malgré les récentes avancées thérapeutiques, peu d’informations sont disponibles concernant ses facteurs pronostiques. Certaines études ont analysé le rôle des caractéristiques clinicopathologiques et des nouvelles stratégies thérapeutiques, mais on connait peut le rôle des facteurs environnementaux et du mode de vie sur le pronostic des patients atteints de LCM. Entre 2008 et 2012, le groupe LYSA a mené en France deux essais cliniques prospectifs multicentriques : LM manteau 2010 SA "RiBVD" (NCI01457144) et Manteau 2007 SJ "LyMa" (NCT00921414). Après une comparaison de ces patients avec les patients de population générale, l’effet de facteurs socioéconomiques et des habitudes de vie sur la survie des patients a été étudié à l’aide d’un questionnaire qualitatif administré à tous les volontaires après le diagnostic. Nos résultats suggèrent qu’un faible niveau d’éducation, un indice de masse corporelle élevé et de la consommation d’alcool sont associés à un risque de décès plus élevé chez les patients atteints de LCM. Toutefois, l’étude de tels facteurs et de leur influence sur un sous-type de LNH aussi rare requiert des échantillons d’étude de taille plus importante. L’élargissement des critères d’inclusion des patients dans les essais cliniques permettrait de sélectionner davantage de patients mais aussi des patients mieux représentatifs de la population générale. Enfin, l’intégration systématique de ce type de questionnaire dans les protocoles d’essais cliniques serait aussi un atout majeur. / Mantle Cell Lymphoma (MCL) is a recently defined entity, typically characterised by the genetic translocation t(11 ;14)(q13 ;q32) and counting for 2 - 10% of all non-Hodgkin Lymphomas. With a median survival between 3 and 5 years after diagnosis, MCL is an agressive disease and despite the recent therapeutic advances little in know about its prognostic factors. Some studies had investigated clinicopathological features and new treatment strategies, but there is a lack of knowledge regarding the impact of lifestyle and environnemental factors on outcome of MCL patients. From 2008 to 2012, the LYSA Group conducted in France two prospective multi center clinical trials on MCL : LM manteau 2010 SA "RiBVD" (NCI01457144) and Manteau 2007 SJ "LyMa" (NCT00921414). After a comparison of these patients with population-based data, socioeconomic factors, lifestyle factors and their influence on survival had been investigated through a qualitative survey administrated to each volunteer after diagnosis. Our findings suggest that low educational attainment, low body body mass index and alcohol consumption are associated with a higher risk of death in MCL. However, to investigate lifestyle factors in this rare NHL subtype, larger studies should be carried out. Clinical trial inclusion criteria must be widen to select more patients and patients more representative of general population. Implementation of these epidemiological studies in clinical practice should be considered.

No description available.

Nas últimas décadas, verificou-se diferenças nas classificações da World Health Organization (WHO) de 2001 e da European Organization for Research and Treatment of Cancer (EORTC) de 1997 para os linfomas cutâneos primários. Em 2005, representantes dessas classificações se reuniram e em consenso estabeleceram a classificação WHO-EORTC que foi adotada pela última classificação da WHO de 2008. O presente estudo visa a avaliar a aplicabilidade dessa nova classificação em casuística retrospectiva de um único centro de referência no diagnóstico e tratamento de linfomas cutâneos. Assim, todos os casos de linfoma cutâneo de células T, excluindo-se micose fungóide (MF) e síndrome de Sézary (SS), no período de 1986 a 2009, foram analisados em relação aos aspectos clínicos, histopatológicos e imunofenotípicos, incluindo-se a realização de novas reações imunoistoquímicas. Os casos foram, então, classificados de acordo com critérios estabelecidos na classificação WHO de 2008. Houve, assim, 33 casos de linfomas cutâneos de células T não-MF e não-SS, sendo 08 (24,2%) de linfoma cutâneo de grandes células anaplásicas, 05 (15,2%) de papulose linfomatóide, 06 (18,1%) de linfoma extranodal de células NK/T tipo nasal, 05 (15,2%) de neoplasia de células dendríticas plasmocitóides blásticas, 05 (15,2%) de linfoma/leucemia de células T do adulto e 04 (12,1%) de linfoma de células T periféricas, sem outra especificação. Portanto, a classificação WHO de 2008 é aplicável à maioria dos casos de linfoma cutâneo de células T não-MF e não-SS. Entretanto, permanecem casos não classificáveis, alguns dos quais com curso clínico agressivo / Recent years have witnessed differences between the World Health Organization (WHO) 2001 and the European Organization for Research and Treatment of Cancer (EORTC) 1997 classification systems of primary cutaneous lymphomas (PCLs). In 2005, a joint WHO-EORTC classification system for PCLs has been reached and was adopted by last WHO 2008 classification. This study was performed to assess the applicability of this new classification to a single referral center. All cutaneous T-cell lymphoma (CTCL) cases, excluding mycosis fungoides (MF) and Sezary syndrome (SS), who were referred from 1986 to 2009 were included. The clinical features, histological and immunohistochemical stainings were reviewed, and additional stains were performed as needed. The cases were then reclassified according to the WHO 2008 classification. There were 33 cases of non-MF and non-SS CTCL, included 08 (24.2%) CD30+ anaplastic large-cell lymphomas, 05 (15.2%) cases of lymphomatoid papulosis, 06 (18.1%) extranodal NK/T-cell lymphoma nasal type, 05 (15.2%) blastic plasmacytoid dendritic cell neoplasm, 05 (15.2%) adult T-cell lymphoma/leukemia and 04 (12.1%) peripheral T-cell lymphomas, unspecified. The new WHO 2008 classification is applicable to most nonMF and non-SS CTCL cases. However, there is still a substantial subset of T-cell PCLs which cannot be classified beyond the unspecified peripheral T-cell category, some of which may have an aggressive course

Evidence that radiation-related cardiovascular disease and second primary cancers can occur in cancer survivors following radiation therapy (RT) has emerged from several independent sources. Cardiotoxicity and second cancers are of particular concern for patients with good prognosis, such as those with Hodgkin lymphoma (HL). HL patients are among the youngest to receive RT, which means that those who are cured of their cancer have decades-long natural life-expectancies during which treatment-related long-term toxicities may cause years of excess morbidity or premature mortality. A considerable amount of research has been conducted to investigate the risk of radiation-related cardiotoxicity and second cancers. However, there are still substantial gaps in knowledge. It is therefore important to improve our understanding regarding these risks and develop treatment approaches and survivorship care to minimise their impact on patients' quality of life. In this thesis, I have investigated the risk of congestive heart failure (CHF) in a cohort of 2619 HL survivors and presented, for the first time, dose-response relationships for risk of CHF versus cardiac radiation doses. I also validated the radiation dosimetry method used to estimate the cardiac doses in this study as well as for other reconstruction methods, versus a gold standard based on the patients' own computed tomography scans. Additionally, I investigated what effect the dose reconstruction errors had on the dose-response relationships. I then focused on modern RT methods and specifically on proton RT. Based on published dose-response relationships (including that developed in this thesis) I predicted cardiovascular and second cancer risks for patients treated with advanced RT. This thesis has provided new knowledge in the study of late effects in HL patients who were treated decades ago as well as for patients treated more recently with advanced RT methods. The results here can be used to facilitate progress towards personalised RT in terms of choosing the appropriate RT method by integrating individualised risk prediction in advanced RT treatment planning. The research here provides the basis for further work towards evidence-based case selection for HL patients for the first NHS proton therapy centres in the UK, opening in 2018-2021.

Le syndrome de Williams-Beuren (SWB} est une maladie génétique rare causée par une microdélétion de la région 7q11.23. A la suite de l'observation clinique d'une jeune fille atteinte du SWB ayant développé un lymphome de Burkitt à l'âge de 7 ans, nous nous sommes intéressé au lien génétique entre SWB et cancer. L'étude d'une série de cas de cancers survenus chez des enfants atteints de SWB a montré que les lymphomes non-hodgkiniens de type B étaient surreprésentés dans cette population puisque 73% des cancers chez les enfants atteints du SWB étaient des LNH-B. La région critique du SWB a été explorée par CGH-array et séquencage haut-débit dans les échantillons sains et tumoraux de 2 patients atteints de SWB. Aucune perte d'hétérozygotie de la région 7q11.23 n'a été trouvé. En outre, une délétion somatique de la région 7q11.23 a été identifiée dans un lymphome de Burkitt sporadique (Guenat D et al., J Hematol Oncol, 2014). Nous avons ensuite exploré les mécanismes de réponses aux dommages à l'ADN dans des lignées de fibroblastes primaires dérivées de patients atteints du SWB ainsi que dans des lignées 293T traitées avec des siRNA ciblant RFC2, BAZ1B et GTF2/, 3 gènes localisés en 7q11.23 et codant des protéines de réparation de l'ADN. Les cellules dérivées de patients SWB ont montré un défaut de signalisation dans les voies ATM/ATR-dépendantes en réponse aux dommages à l'ADN (Guenat D et al., DNA repair, article soumis). L'haploinsuffisance de la région 7q11.23 associée au SWB pourrait donc jouer un rôle dans la lymphomagenèse B par l'altération de voies de réponse aux dommages à l'ADN ATM/ATR-dépendantes. Cependant, ces résultats mériteraient d'être confirmés dans des modèles murins reproduisant le génotype complet du SWB. Enfin, des données épidémiologiques exhaustives sur l'incidence des pathologies tumorales chez les individus atteints du SWB sont indispensables pour affirmer qu'une prédisposition au cancer existe chez ces patients / Williams-Beuren syndrome (WBS) is a genetic disorder caused by a microdeletion at 7q11.23. The case of a young girl with WBS who developed a Burkitt lymphoma at the age of 7 leads us to explore the genetic link between WBS and cancer. The study of a series of cancers occurred in WBS patients during childhood have shown that B-cell non hodgkin lymphoma are over-represented in this population since 73% cancer cases in WBS were B-NHL. The critical region of WBS was explored by array-CGH and high-throughput sequencing in normal and tumor samples from WBS patients. No loss of heterozygosity at 7q11.23 was found. ln addition, a somatic deletion at 7q11.23 was observed in a sporadic case of Burkitt lymphoma (Guenat D et al., J Hematol Oncol, 2014). DNA damage response mechanisms were then explored in primary fibroblast cell lines derived from WBS patients as well as in 293T cell line treated with siRNA targeting RFC2, GTF2/ and BAZ1 B, 3 genes mapping at 7q11.23 that encode proteins involved in DNA damage response. WBS patients cell lines have shown a defect in ATM/ ATR-dependent DNA damage response pathways (Guenat D et al., DNA Repair, article submitted). Haploinsufficiency of the 7q11.23 region associated with WBS might play a role in B-cell lymphomagenesis through the alteration of ATM/ATR-dependent DNA damage response pathways. However, these results deserve to be confirmed in mouse models that reproduce the complete genotype of human WBS. Finally, strong epidemiological data would be required to confirm the predisposition to cancer in WBS patients.

Dissertation (Ph.D.)--University of South Florida, 2009. / Title from PDF of title page. Document formatted into pages; contains 115 pages. Includes vita. Includes bibliographical references.

A previous population-based study of survival in Chronic Lymphocytic Leukemia (CLL) patients in the province of Manitoba demonstrated a lower five-year relative survival among CLL patients compared with the age- and gender-adjusted general population. This decreased relative survival was most pronounced among elderly male CLL patients. In this study, we have demonstrated that the reduced five-year relative survival observed in CLL patients compared to the general population of Manitoba may partially be attributed to increased risk of second cancers and non-referral to specialized CLL clinics. The increased risk of second cancers in CLL patients compared to Follicular Lymphoma (FL), a similar indolent B cell malignancy, was only observed after CLL diagnosis indicating that a CLL-specific factor may be responsible for the increased risk of second cancers in these patients. The risk of second cancers is independent of treatment and surveillance bias but is further increased with chemotherapy. A superior outcome in CLL patients who have been referred to the CancerCare Manitoba (CCMB) specialized CLL clinic was observed that was independent of age, gender, treatment and history of previous cancers. This superior outcome was most pronounced in the elderly CLL patients. We propose that CLL patients should be referred to CLL-specific hematologists and, where not possible, that guidelines created by such experts be followed. Appropriate screening for second cancers should be performed during routine follow up of CLL patients.

Lymphomas are neoplasms of the human immune system and can be divided into two categories, Hodgkin’s lymphoma (HL) and non-Hodgkin lymphoma (NHL). Anaplastic large cell lymphoma (ALCL) is a form of NHL that shares a common distinctive feature with HL, the overexpression CD30. The expression of cytokine receptor CD30 is restricted to proliferating B and T lymphocytes in healthy individuals while its overexpression is associated with several lymphoproliferative diseases such as ALCL and HL. The activation of CD30 via ligand or antibodies triggers various cellular responses ranging from apoptosis to cell proliferation and it is thought that the variable cellular response to CD30 activation may be due to cell surface levels of CD30. The human CD30 gene is regulated at the transcriptional level and previous studies characterising its promoter have identified several factors that regulate the expression this gene. However none of these identified factors explain for the high levels of CD30 observed in HL and ALCL. Therefore this study focused on the identification and functional analysis of transcriptionally active regions located up or downstream of the CD30 promoter region. The first aim for this study was to identify and characterise regions within the human CD30 gene that are involved in its transcriptional regulation. Phylogenetic footprinting identified several regions downstream of the CD30 promoter that displayed high levels of sequence homology indicating potential functional significance. Validation of these regions through two in vivo approaches, DNase 1 hypersensitivity assay and chromatin accessibility studies localised potential transcriptionally active regions to intron 1 of the CD30 gene.