There is an increasing evidence that alterations in chromatin remodeling play an important role in tumorigenesis. The SWI/SNF chromatin remodeling complexes contribute to the regulation of gene expression by altering the local chromatin structure. Depending on the context, they can act as either transcriptional activators or repressors. All SWI/SNF subcomplexes contain one of two ATPase subunits, Brm (Brahma) or Brg1 (Brahma related gene 1), which provide the energy for remodeling. Malignant melanoma is an aggressive cancer and is known for its notorious resistance to conventional anticancer therapies. MITF (microphthalmia-associated transcription factor) plays an essential role in melanoma biology and is placed on the central crossroad in the regulation of melanocyte development, differentation, maintenance of lineage identity, and survival of both normal and malignant melanocytes. Our results show that the active SWI/SNF complex is strictly required for the expression of MITF. This complex is also required for expression of some transcriptional MITF targets. The survival of melanoma cells is absolutely dependent on functional SWI/SNF complex and all subunits of this complex are expressed at high levels in melanoma cell lines. Primarily, Brg1-containing subcomplexes are more important for MITF...

Les principaux régulateurs de la prolifération cellulaire sont les Cdk (cyclin dependent kinase), dont l'activité dépend de leur association avec leurs partenaires, les cyclines. Le contrôle du niveau d'expression des cyclines représente le premier mécanisme par lequel l'activité des Cdk est régulée. Cette régulation est essentielle pour maintenir l'équilibre prolifération/différenciation de la peau. Cependant, les mécanismes mis en jeu restent peu connus.<br />Nous avons montré que Brm, protéine des complexes de remodelage de la chromatine SWI/SNF, est responsable de la répression de la cycline A par la mise en place ou le maintien de deux nucléosomes situés sur les sites d'initiation de la transcription. De plus, nous avons mis en évidence que l'absence de brm conduit à accélérer la progression des cellules dans le cycle cellulaire en jouant sur le déroulement de la phase S. Cependant, les cellules dépourvues de brm présentent également une mitose rallongée et des aberrations chromosomiques. Ceci pourrait être la conséquence de la dérégulation de trois oncogènes : c-myc, cycline A et cycline E et pourrait expliquer pourquoi brm est mutée dans de nombreux cancers.<br />Enfin, nous avons montré que l'entrée en différenciation des kératinocytes s'accompagne d'une forte expression de p21 qui entraîne un arrêt en G2/M en inhibant les complexes Cycline A/Cdk. Cependant, les kératinocytes en différenciation ne peuvent maintenir cet arrêt et entre dans un état G1 à 4N, caractérisé par une forte expression de la Cycline E et l'absence de Cyclines de G2/M.

Does the lead industry have a future, in the face of the developing environmental challenge? This thesis addresses this question and concludes, it should have for the foreseeable future, providing it adopts the changes detailed. These changes are posited within a framework, which consists of a strategy, approaches and tools. The changes are both technical and philosophical. They are technical, in the sense that the tools and approaches provide practical means whereby the environmental `risks' may be identified, assessed and managed. They are philosophical, because they set out and identify the features of a new conceptual paradigm, whose basis is in the concept of the `risk society'. The paradigm is significantly more holistic, multi-dimensional, inherently flexible, and is intended to be reflexive. Adoption of the elements of the framework, will facilitate a more effective establishment, and management of environmental `risk' credentials, which will help encourage better environmental decision making. Hence, it will facilitate, the balancing of resource consumption and environmental impact costs, versus social and economic benefits, in an improved manner. The modelling approaches, and selected inventory and environmental impact assessment tools, enclosed within this thesis, have been designed to facilitate the development of, and to function within, the new paradigm. These have been developed for BRM and MIM case studies, and function at the site-specific and the cradle-to-gate scales. The former consider the company site of Britannia Refined Metals (BRM) Ltd., where refining to produce primary and secondary refined lead products takes place, whilst the latter consider the life-cycle of the refined primary lead products of MIM Ltd. The modelling approaches have also been designed so, that they may be re-aggregated into models able to operate at many different scales, as required. The framework, and its elements, are applicable for all industries facing similar challenges.

Les sarcomes épithélioides sont caractérisés dans 85% des cas par une perte d'expression nucléaire de la protéine SMARCB1, codée par un gène suppresseur de tumeurs situés en 22q11 impliqué dans la génèse des tumeurs rhabdoides malignes. L'exploration par BAC-FISH (Bacterial Artificial Chromosome- Fluorescence In Situ Hybridization) d'une série de 40 sarcomes épithélioides a permis d'établir que cette perte d'expression était secondaire dans 85% des cas à des délétions homozygotes et a mis en évidence le premier cas de sarcome épithélioide associé à une délétion germinale de SMARCB1, altération jusqu'alors uniquement identifiée dans les tumeurs rhabdoides malignes. Nous avons par la suite testé le gène suppresseur de tumeurs SMARCA4 comme gène candidat impliqué dans les sarcomes épithélioides SMARCB1-conservés à partir d'une série rétrospective de 16 cas. SMARCA4 code la sous-unité ATPase du complexe BAF dont SMARCB1 représente une sous unité. Ce screening initial a permis d'identifier 6 cas de sarcomes SMARCA4-inactivés dont la localisation était exclusivement thoracique et dont les caractéristiques clinique et anatomopathologique stéréotypées ont permis le recrutement prospectif et rétrospectif de nouveaux cas. L'étude par RNA-sequencing d'une fraction de notre cohorte (n=13/19) a confirmé leur homogénéité transcriptomique et souligné leur parenté avec les tumeurs rhabdoides SMARCB1 et SMARCA4 déficientes. L'absence de mutation germinale fréquente (n=1/11) a fait proposer le terme de sarcome thoracique SMARCA4-déficient (SMARCA4-DTS) en proscrivant l'utilisation du qualificatif « rhabdoide ». La parenté transcriptomique de ces tumeurs laisse entrevoir des vulnérabilités thérapeutiques communes qui restent à identifier / Epithelioid sarcomas (ES) display loss of SMARCB1 nuclear expression in 85% of cases. SMARCB1 is encoded by a tumor suppressor gene located in 22q11 which was first linked to cancer in malignant rhabdoid tumors. While investigating a series of 40 epithelioid sarcomas with BAC-FISH (Bacterial Artificial Chromosome-Fluorescence In Situ Hybridization), we demonstrated that SMARCB1 loss in ES occurred through genomic deletions in 85% of cases. We were also able to highlight the first case of ES associated with a heterozygous SMARCB1 deletion in the germ line, which feature was previously thought to be restricted to malignant rhadboid tumors (MRT). We subsequently investigated a series of 16 SMARCB1-retained ES to identify its underlying culprit gene with a focus on the candidate tumor suppressor gene SMARCA4. SMARCA4 encodes one of the ATPase subunit of BAF complexes. Interestingly, SMARCB1 is also a core submit of these complexes which regulate chromatin remodeling. We were able to identify a set of 6 cases displaying SMARCA4 inactivation with this discovery cohort. The review of medical records highlighted these cases had similar presentation : all tumors presented with large compressive and aggressive mediastinopulmonary masses. We further recruited 13 cases based on these characteristics including 5 prospective cases. The characterization of their transcriptomes by RNA-sequencing (n=13/19) confirmed their remarkable homogeneity, all our samples clustering together with MRT. However our variant diverge from malignant rhabdoid tumors as it lacks SMARCA4 alteration in the germline (n=0/11) and displays complex polyploidy genetic profiles. We therefore called this new tumor variant “SMARCA4-deficient thoracic sarcoma” (SMARCA4-DTS). The transcriptomic vicinity of SMARCA4-DTS and MRT let foresee they share common therapeutic vulnerabilities

Purpose – This research aims to explore the effectiveness of utilising Benefits Realisation Management (BRM) as part of comprehensive success measures, emphasising the stage in-between appraisal and evaluation of projects in the UK public sector. Design/methodology/approach – The study is constructed as a qualitative case study. Semi-structured interviews are used as part of the inductive, exploratory approach to achieve the study's objectives. It employs an approach based on grounded theory for its analysis. Findings – This paper suggests that Benefits Realisation Management is not used effectively in the UK public sector during projects lifetime to control and monitor projects and ensure their success. The current reviews of projects and programmes, through their execution, may not be sufficient. Research limitations/implications – This study offers contributions to the project success literature and benefits management literature by adding empirically supported insights about BM utilisation during project reviews. The research may be limited primarily by the research method – predominantly the snow-balling data collection. The assumptions made about the UK public sector may limit the broader generalisation of the findings. Practical implications – This research may be used to advise the practising managers of the need to maintain benefits orientation after appraisal throughout a project's lifetime and after delivery. Project governance structures are advised to update and improve their current project review practices. The study additionally identifies possible obstacles to the process and biases. Originality/value – This paper attempts to fill a literature gap by providing empirical results that explore the success definition and measures and the effectiveness of BRM during project execution and gate reviews. Keywords: Benefits Management; Project Success; Project Performance; Performance Measurement; Public Sector. Paper type: Research Thesis