Retinoblastoma is the prototype genetic cancer caused by mutations disrupting the RB1 tumor suppressor gene. Following loss of RB1, retinoblastoma acquires further genetic changes in a characteristic set of oncogenes and tumor suppressors including gains of the oncogenes KIF14, DEK, E2F3, and MYCN and loss of the tumor suppressor CDH11. The constellation of genetic changes is the postulated genetic pathway leading to retinoblastoma. However, advances in molecular diagnostic testing for RB1 gene mutations allows detection of at least one RB1 mutation in 98% of unilateral retinoblastomas leaving 2% of cases with undetectable RB1 mutations (RB1+/+ retinoblastoma). RB1+/+ retinoblastomas have high-level MYCN gene amplification (>30 copies) and few other genetic changes. In addition, RB1+/+ retinoblastoma present earlier than conventional RB1-/- retinoblastoma and show histologic features similar to MYCN-amplified neuroblastoma. Altogether, this study describes a distinct genetic subset of retinoblastoma characterized by wild-type RB1 gene and high-level MYCN gene amplification.

Retinoblastoma is the prototype genetic cancer caused by mutations disrupting the RB1 tumor suppressor gene. Following loss of RB1, retinoblastoma acquires further genetic changes in a characteristic set of oncogenes and tumor suppressors including gains of the oncogenes KIF14, DEK, E2F3, and MYCN and loss of the tumor suppressor CDH11. The constellation of genetic changes is the postulated genetic pathway leading to retinoblastoma. However, advances in molecular diagnostic testing for RB1 gene mutations allows detection of at least one RB1 mutation in 98% of unilateral retinoblastomas leaving 2% of cases with undetectable RB1 mutations (RB1+/+ retinoblastoma). RB1+/+ retinoblastomas have high-level MYCN gene amplification (>30 copies) and few other genetic changes. In addition, RB1+/+ retinoblastoma present earlier than conventional RB1-/- retinoblastoma and show histologic features similar to MYCN-amplified neuroblastoma. Altogether, this study describes a distinct genetic subset of retinoblastoma characterized by wild-type RB1 gene and high-level MYCN gene amplification.

Urinary bladder urothelial carcinoma is the most common cancer of the urinary tract. About 70% of the diagnosed tumors classified as Non-invasive tumor, which is usually multiple. Despite surgical removal and perioperative chemotherapy, tumor recurrence is not uncommon. However, the chance for such non-invasive tumors to advance to the muscle-invasive stage is relatively small and the 5-year survival rate approaches 95%. The rest 30% are classified as invasive tumors which usually pursue aggressive clinical course. In spite of radical cystectomy in conjunction with debilitating chemotherapy and/or radiotherapy, more than 50% of invasive tumors eventually spread to distant organs. The 5-year survival rate for patients with distant metastasis is only about 6%. The current challenge in the management of urinary bladder carcinoma is the lack of powerful prognostic marker and promising therapeutic agents. Accordingly, to identify novel biomarks to adjust therapeutic strategy is mandatory. The BCL6 proto-oncogene encodes a nuclear transcriptional repressor, it¡¦s inhibits DNA repair pathways and TP53. Perturbation of both these pathways may contribute to normal cell function by repressing DNA damage responses and permitting somatic hypermutation but , in the context of malignancy, this could lead to mutations promoting aggressive tumor. Several studies have demonstrated that BCL6 play a role in different cancer types, however, the function of BCL6 in bladder cancer is understood. Therefore, in this study, we will analyze the endogenous BCL6 mRNA and total/activated BCL6 protein in various bladder cancer cell lines, including BFTC905, and J82. Then we will knockdown of the BCL6 gene by shRNA interference and analyze how it implicates various cellular processes essential to cancerous states. And then we will be analyzed the affection of cell survival, migration and invasion. Conversely, Overexpression of BCL6 in bladder cancer cell lines will be assessed cell proliferation, migration and invasion. Finally, studying it¡¦s affection in vivo. We demonstrate that BCL6 is correlated with bladder cancer.

Un nouveau paradigme tente de s’imposer en oncologie ; identifier les anomalies moléculaires dans la tumeur d’un patient, et proposer une thérapie ciblée, en relation avec ces altérations moléculaires. Nous discutons ici des altérations moléculaires considérées pour une orientation thérapeutique, ainsi que de leurs méthodes d’identification : parmi les altérations recherchées, les anomalies de nombre de copies tiennent une place importante, et nous nous concentrons plus précisément sur leur identification par hybridation génomique comparative (aCGH). Nous montrons, d’abord à partir de lignées cellulaires caractérisées, que l’analyse du nombre de copies par aCGH n’est pas triviale et qu’en particulier le choix de la centralisation peut être déterminant ; différentes stratégies de centralisation peuvent conduire à des profils génomiques différents, certains aboutissant à des interprétations erronées. Nous montrons ensuite, à partir de cohortes de patients, qu’une conséquence majeure est de retenir ou non certaines altérations actionnables dans la prise de décision thérapeutique. Ce travail nous a conduit à développer un workflow complet dédié à l’analyse aCGH, capable de prendre en charge les sources de données les plus courantes. Ce workflow intègre les solutions discutées, assure une entière traçabilité des analyses, et apporte une aide à l’interprétation des profils grâce à des solutions interactives de visualisation. Ce workflow, dénommé rCH, a été implémenté sous forme d’un package R, et déposé sur le site Bioconductor. Les solutions de visualisation interactives sont disponibles en ligne. Le code de l’application est disponible pour une installation sur un serveur institutionnel. / In oncology, a new paradigm tries to impose itself ; analyzing patient’s tumors, and identifying molecular alterations matching with targeted therapies to guide a personalized therapeutic orientation. Here, We discuss the molecular alterations possibly relevant for a therapeutic orientation, as well as the methods used for their identification : among the alterations of interest, copy number variations are widely used, and we more specifically focus on comparative genomic hybridization (aCGH). We show, using well characterized cell lines, that identification of CNV is not trivial. In particular, the choice for centralizing profiles can be critical, and different strategies for adjusting profiles on a theoretical 2n baseline can lead to erroneous interpretations. Next, we show, using tumor samples, that a major consequence is to include, or miss, targetable alterations within the decision procedure. This work lead us to develop a comprehensive workflow, dedicated to aCGH analysis. This workflow supports the major aCGH platforms, ensure a full traceability of the entire process and provides interactive visualization tools to assist the interpretation. This workflow, called rCGH, has been implemented as a R package, and is available on Bioconductor. The interactive visualization tools are available on line, and are ready to be installed on any institutional server.

A perda auditiva é o defeito mais comum ao nascimento e cerca de 70 milhões de pessoas no mundo apresentam algum grau de perda auditiva. Além da alta incidência, as implicações da perda auditiva na linguagem, na cognição e no desenvolvimento emocional e social reforçam sua importância. No entanto, em grande parte dos pacientes, a causa da deficiência auditiva não é esclarecida. Nós usamos hibridação comparativa do genoma baseada em arrays (Array Comparative Genomic Hybridization aCGH) para investigar alterações no número de cópias de segmentos de DNA (Copy Number Variation CNV) em 31 indivíduos que apresentavam deficiência auditiva e sinais clínicos adicionais, mas que não puderam ser classificados em síndrome conhecida. A escolha de indivíduos sindrômicos se baseou no pressuposto de que, em média, apresentam alterações genômicas maiores e, portanto, mais provavelmente detectáveis com o uso de aCGH de 1 Mb, que era a plataforma disponível no início do projeto. CNVs não descrita em bancos de dados de indivíduos normais foram identificadas em oito pacientes, quatro delas ocorreram de novo enquanto as outras quatro foram herdadas de um genitor fenotipicamente normal. As alterações de novo definem segmentos cromossômicos que provavelmente contém genes relacionados à deficiência auditiva e sensíveis a dose, especificamente: 1q23.3-q25.2, 2q22q23, 6p25.3 e 11q13.2-q13.4. As alterações raras identificadas tanto nos pacientes quanto em um genitor normal poderiam ser um evento ao acaso, sem papel na deficiência auditiva; no entanto, a possibilidade de que essas alterações possam funcionar como fatores de predisposição não podem ser descartadas. Se considerarmos apenas as CNVs de novo como causativas dos fenótipos investigados, detectamos quatro pacientes portadores entre os 31 investigados (13%). Se considerarmos também as CNVs herdadas como possivelmente causativas, a taxa de desequilíbrios cromossômicos associados à surdez será de 26%. Esses resultados são provavelmente uma substimativa e esses números seriam possivelmente maiores com o uso de uma das plataformas de alta resolução disponíveis atualmente. Esses resultados, embora limitados, indicam que investigação por aCGH em pacientes com surdez sindrômica idiopática está entre os testes mais eficientes para detectar etiologia dos fenótipos, devendo ser incorporado à rotina no diagnóstico e aconselhamento genético. / Hearing loss is the most common congenital deficiency and about 70 million people worldwide present some degree of hearing impairment. In addition to its high incidence, hearing loss impacts language, cognition and social and emotional development. However, in a large proportion of patients, the cause of the hearing deficiency cannot be elucidated. We screened copy number changes by 1 Mb-array Comparative Genomic Hybridization (aCGH) in 31 individuals with syndromic hearing impairment whose clinical features were untypical for known disorders. The choice of evaluating syndromic rather than non-syndromic individuals was based on the assumption that they are more likely to carry larger genomic alterations which could be more easily detected by the comparatively low resolution 1 Mb aCCG, which was the available platform when this project started. Copy number changes (CNV) not documented in the database of normal individuals were detected in eight patients, four de novo imbalances and four inherited from a normal parent. The de novo alterations define candidate chromosome segments likely to harbor dosage sensitive genes related to hearing impairment, namely 1q23.3-q25.2, 2q22q23, 6p25.3 and 11q13.2- q13.4. The rare imbalances also present in normal parents might be casually associated with hearing impairment, but also have a possible role as a predisposition factor. When only the de novo CNVs were considered causative for the disease phenotypes, our study revealed relevant copy number changes in 4 patients (13%). If we also count the rare CNVs that had been inherited as possibly causative, the frequency of chromosome imbalances associated with syndromic deafness in our sample becomes 26%. These figures are probably underestimates and will probably become larger when high resolution oligoarray platforms are applied. These results indicate that aCGH is an efficient tool for defining the etiology of syndromic deafness and its use in routine diagnosis of hearing impairment and for genetic counseling is highly recommended.

A perda auditiva é o defeito mais comum ao nascimento e cerca de 70 milhões de pessoas no mundo apresentam algum grau de perda auditiva. Além da alta incidência, as implicações da perda auditiva na linguagem, na cognição e no desenvolvimento emocional e social reforçam sua importância. No entanto, em grande parte dos pacientes, a causa da deficiência auditiva não é esclarecida. Nós usamos hibridação comparativa do genoma baseada em arrays (Array Comparative Genomic Hybridization aCGH) para investigar alterações no número de cópias de segmentos de DNA (Copy Number Variation CNV) em 31 indivíduos que apresentavam deficiência auditiva e sinais clínicos adicionais, mas que não puderam ser classificados em síndrome conhecida. A escolha de indivíduos sindrômicos se baseou no pressuposto de que, em média, apresentam alterações genômicas maiores e, portanto, mais provavelmente detectáveis com o uso de aCGH de 1 Mb, que era a plataforma disponível no início do projeto. CNVs não descrita em bancos de dados de indivíduos normais foram identificadas em oito pacientes, quatro delas ocorreram de novo enquanto as outras quatro foram herdadas de um genitor fenotipicamente normal. As alterações de novo definem segmentos cromossômicos que provavelmente contém genes relacionados à deficiência auditiva e sensíveis a dose, especificamente: 1q23.3-q25.2, 2q22q23, 6p25.3 e 11q13.2-q13.4. As alterações raras identificadas tanto nos pacientes quanto em um genitor normal poderiam ser um evento ao acaso, sem papel na deficiência auditiva; no entanto, a possibilidade de que essas alterações possam funcionar como fatores de predisposição não podem ser descartadas. Se considerarmos apenas as CNVs de novo como causativas dos fenótipos investigados, detectamos quatro pacientes portadores entre os 31 investigados (13%). Se considerarmos também as CNVs herdadas como possivelmente causativas, a taxa de desequilíbrios cromossômicos associados à surdez será de 26%. Esses resultados são provavelmente uma substimativa e esses números seriam possivelmente maiores com o uso de uma das plataformas de alta resolução disponíveis atualmente. Esses resultados, embora limitados, indicam que investigação por aCGH em pacientes com surdez sindrômica idiopática está entre os testes mais eficientes para detectar etiologia dos fenótipos, devendo ser incorporado à rotina no diagnóstico e aconselhamento genético. / Hearing loss is the most common congenital deficiency and about 70 million people worldwide present some degree of hearing impairment. In addition to its high incidence, hearing loss impacts language, cognition and social and emotional development. However, in a large proportion of patients, the cause of the hearing deficiency cannot be elucidated. We screened copy number changes by 1 Mb-array Comparative Genomic Hybridization (aCGH) in 31 individuals with syndromic hearing impairment whose clinical features were untypical for known disorders. The choice of evaluating syndromic rather than non-syndromic individuals was based on the assumption that they are more likely to carry larger genomic alterations which could be more easily detected by the comparatively low resolution 1 Mb aCCG, which was the available platform when this project started. Copy number changes (CNV) not documented in the database of normal individuals were detected in eight patients, four de novo imbalances and four inherited from a normal parent. The de novo alterations define candidate chromosome segments likely to harbor dosage sensitive genes related to hearing impairment, namely 1q23.3-q25.2, 2q22q23, 6p25.3 and 11q13.2- q13.4. The rare imbalances also present in normal parents might be casually associated with hearing impairment, but also have a possible role as a predisposition factor. When only the de novo CNVs were considered causative for the disease phenotypes, our study revealed relevant copy number changes in 4 patients (13%). If we also count the rare CNVs that had been inherited as possibly causative, the frequency of chromosome imbalances associated with syndromic deafness in our sample becomes 26%. These figures are probably underestimates and will probably become larger when high resolution oligoarray platforms are applied. These results indicate that aCGH is an efficient tool for defining the etiology of syndromic deafness and its use in routine diagnosis of hearing impairment and for genetic counseling is highly recommended.

Étudiant en histoire à La Sorbonne, Henri Rollet (1917-2003) découvre l’action sociale de l’Église, grâce à Mgr Chaptal, évêque auxiliaire de Paris. Sa responsabilité de « patron » dans l’industrie ne l’empêche pas, en 1948, de soutenir une thèse de doctorat qui retrace l’action sociale des catholiques en France (1871-1901). Dès l’année suivante, il est nommé président du Secrétariat Social de Paris. Plus tard il deviendra président national, puis international de l’action catholique des hommes, auditeur laïc au Concile Vatican II, et ensuite président de l’Institut Catholique de Paris. Pendant cette période, il écrit plusieurs ouvrages souvent historiques sur le rôle des catholiques sociaux, rédige beaucoup d’articles, donne de très nombreuses conférences. C’est essentiellement à partir des informations et commentaires donnés par la presse sur ses livres, articles, et conférences, que l’on peut découvrir le comportement, les opinions, et les prises de position de ce laïc engagé. Comment, au cours de cette deuxième partie du XX° siècle, a-t-il conçu et exercé sa mission de laïc engagé ? Comment a-t-il porté témoignage de sa foi, en France, mais également dans d’autres pays ? Comment a-t-il milité pour donner au laïc un rôle plus important au sein de l’Église ? Comme on le verra, un certain nombre de sujets énoncés il y a cinquante ans, sont encore d’actualité ! À partir des documents retrouvés, ce travail tente de répondre à ces questions, en montrant toute l’importance et l’actualité de la Doctrine Sociale de l’Église. / While studying history at the Sorbonne, Henri Rollet (1917-2003) discovered the Church’s social teaching through Emmanuel Chaptal, an auxiliary bishop of Paris. Though he was an industry manager, he nevertheless submitted a doctoral thesis in 1948 on how Catholics had engaged with French society between 1871 and 1901. The following year, he was appointed President of the Secrétariat Social de Paris. Later he would become national President and then international President of Catholic Action for men, a lay auditor at Vatican II, and then president of the Institut Catholique de Paris. During this period he wrote several works on the role of socially engaged Catholics, mostly of a historical kind, as well as many articles; and he gave numerous conferences. It is essentially though press reports and commentaries on his books, articles and talks that one can discover who this committed lay person was: his attitudes, his opinions, the stands he took. How did this committed lay person conceive and carry out his mission in the second half of the 20th century? How did he bear witness to his faith, not only in France but also in other countries? How did he struggle to give the lay person a more significant role within the Church? As will be seen, a number of topics worked through fifty years ago are still all too relevant. Drawing on newly discovered documents, this study attempts to answer these questions, while bringing out the full importance and relevance of Catholic Social Teaching.

Aneuploidy frequency increases with advanced female age and results in infertility or live birth of affected individuals. Aneuploidies occur mainly during female meiosis. Polar bodies biosied from oocytes after first and second meiosis were analyzed using array comparative genomic hybridization testing for all chromosomes. More than a half of tested oocytes were aneuploid. Aneuploidies as a result of nondisjunction in meio-sis II were slightly more frequent than meiosis I errors. Premature chromatide predivisi-on was absolutely predominant among errors occurring during meiosis I. Despite the fact that aneuploidies were detected for each chromosome, most aneuploidies were detected for small acrocentric chromosomes. Possible mechanisms of aneuploidy formation are discussed in context of information obtained by the means of animal biotechnologies at different species of mammals.

Paediatric high grade glioma (HGG), including diffuse intrinsic pontine glioma (DIPG) are highly aggressive tumours with no effective cures. Lack of understanding of the molecular biology of these tumours, in part due to lack of well-characterised pre-clinical models, is a great challenge in the development of novel therapies. Analysis of paired cell culture/biopsy samples in this study revealed that paediatric HGG short-term cell cultures retain many of the tumour characteristics in vivo. Using a genome-wide approach, copy number, gene and miRNA expression, and methylation changes were characterised in 17 paediatric HGG-derived short-term cell cultures including 3 from DIPG. The majority of the genomic changes were unique from those arising in adult HGG. Approximately 65% (11/17) of paediatric HGG short-term cell cultures had balanced genetic profiles resembling normal karyotypes. The most frequent copy number gain and loss were detected at 14q11.2 (94%) and 8p11.23-p11.22 (59%), respectively. H3F3A (K27M) mutation was present in 2/17 (12%) cases and concurrent loss of CDKN2A and BRAFV600E in 1/17 (6%) case. Genes involved in reelin/PI3K signaling (DAB1), RTK signaling (PTPRE), and arginine biosynthesis (ASS1 and ASL) were frequently deregulated by methylation in these tumours. The anti-growth and anti-migratory properties of DAB1 and PTPRE were demonstrated in vitro. Preliminary investigations validated the therapeutic potential of ADI-PEG20 (arginine depletion), and PI-103 (PI3K/mTOR inhibition) in a subset of paediatric HGG short-term cell cultures. This study has identified novel genetic and epigenetic changes in paediatric HGG that may, following further validation, be translated into potential biomarkers and/or therapeutic targets.

The primary aim of this study was to determine the effectiveness of array-based technology for detecting and quantifying the presence of mosaicism. This aim was achieved by studying individuals having mosaicism for Down syndrome. SNP arrays were performed on 13 samples from individuals with mosaicism for trisomy 21, 13 samples from individuals with normal chromosome 21complements (negative controls) and 5 samples from individuals with full or partial trisomy 21 (positive controls). In addition, BAC arrays were processed on 6 samples from individuals with mosaicism for trisomy 21, 3 negative controls and 1 positive control. These studies have shown that array-based technology is effective for detecting mosaicism that is present in 20% or more cells with the results being consistent for both platforms. We also demonstrated the strength of array-based technology to identify previously unrecognized chromosomal mosaicism. A second aim of this study was to gain insight regarding the effect that trisomy 21 has on telomere attrition and the frequency of chromosomal instability. This study provides the first reported measure of both chromosome-specific telomere lengths and the frequency of acquired chromosome abnormalities in trisomic cells and isogenic euploid cells obtained from the same individuals. A chromosome-specific telomere length assay was performed on lymphocytes obtained from 24 young individuals with mosaicism for Down syndrome. While differences in overall telomere signal intensities were observed between the euploid and trisomic cells within a person, strikingly similar profiles for chromosome-specific telomere intensities were observed between the cell types within a person. Analyses were also completed on lymphoblast samples obtained from 8 older individuals with mosaicism for Down syndrome, including 5 individuals without dementia and 3 individuals with dementia. In the older study subjects, a significant inverse correlation was observed between telomere length and the frequency of micronuclei, suggesting that telomeric shortening is leading to an increased frequency of chromosomal instability, possibly through dicentric chromosome formation. However, further studies of more individuals, especially additional analyses of older individuals, are needed. These future studies may help to identify genomic regions of interest and serve to inform investigators of potential candidate genes in the etiology of dementia.