Characterization of the cork oak transcriptome dynamics during acorn development

Background: Cork oak (Quercus suber L.) has a natural distribution across western Mediterranean regions and is a keystone forest tree species in these ecosystems. The fruiting phase is especially critical for its regeneration but the molecular mechanisms underlying the biochemical and physiological changes during cork oak acorn development are poorly understood. In this study, the transcriptome of the cork oak acorn, including the seed, was characterized in five stages of development, from early development to acorn maturation, to identify the dominant processes in each stage and reveal transcripts with important functions in gene expression regulation and response to water. Results: A total of 80,357 expressed sequence tags (ESTs) were de novo assembled from RNA-Seq libraries representative of the several acorn developmental stages. Approximately 7.6 % of the total number of transcripts present in Q. suber transcriptome was identified as acorn specific. The analysis of expression profiles during development returned 2,285 differentially expressed (DE) transcripts, which were clustered into six groups. The stage of development corresponding to the mature acorn exhibited an expression profile markedly different from other stages. Approximately 22 % of the DE transcripts putatively code for transcription factors (TF) or transcriptional regulators, and were found almost equally distributed among the several expression profile clusters, highlighting their major roles in controlling the whole developmental process. On the other hand, carbohydrate metabolism, the biological pathway most represented during acorn development, was especially prevalent in mid to late stages as evidenced by enrichment analysis. We further show that genes related to response to water, water deprivation and transport were mostly represented during the early (S2) and the last stage (S8) of acorn development, when tolerance to water desiccation is possibly critical for acorn viability. Conclusions: To our knowledge this work represents the first report of acorn development transcriptomics in oaks. The obtained results provide novel insights into the developmental biology of cork oak acorns, highlighting transcripts putatively involved in the regulation of the gene expression program and in specific processes likely essential for adaptation. It is expected that this knowledge can be transferred to other oak species of great ecological value.Fundação para a Ciência e a Tecnologi

Ovarian cancer

Ovarian cancer is not a single disease and can be subdivided into at least five different histological subtypes that have different identifiable risk factors, cells of origin, molecular compositions, clinical features and treatments. Ovarian cancer is a global problem, is typically diagnosed at a late stage and has no effective screening strategy. Standard treatments for newly diagnosed cancer consist of cytoreductive surgery and platinum-based chemotherapy. In recurrent cancer, chemotherapy, anti-angiogenic agents and poly(ADP-ribose) polymerase inhibitors are used, and immunological therapies are currently being tested. High-grade serous carcinoma (HGSC) is the most commonly diagnosed form of ovarian cancer and at diagnosis is typically very responsive to platinum-based chemotherapy. However, in addition to the other histologies, HGSCs frequently relapse and become increasingly resistant to chemotherapy. Consequently, understanding the mechanisms underlying platinum resistance and finding ways to overcome them are active areas of study in ovarian cancer. Substantial progress has been made in identifying genes that are associated with a high risk of ovarian cancer (such as BRCA1 and BRCA2), as well as a precursor lesion of HGSC called serous tubal intraepithelial carcinoma, which holds promise for identifying individuals at high risk of developing the disease and for developing prevention strategies

Chirurgie annexielle prophylactique des femmes à risque héréditaire : vers de nouvelles pistes ?

International audienceHereditary ovarian carcinomas represent 10% of cases of the around 4,500 yearly ovarian cancers in France. They principally consist of high-grade serous carcinomas. They are especially observed in mutation carriers on genes BRCA1 or 2 and, at a lesser degree, on genes of the hereditary non-polyposis colorectal cancer (HNPCC) syndrome. Due to the absence of an effective screening method for this highly lethal disease, laparoscopic prophylactic adnexectomy is strongly recommended as soon as possible, after a genetic counselling session. However, not all women accept the outcomes of an early menopause, especially if a substitutive treatment is contra-indicated. Recent data obtained from the thorough examination of risk-reducing salpingo-oophorectomy (RRSO) specimens highlight the pivotal role of the Fallopian tube in the pathogenesis of most ovarian carcinomas, especially its fimbrial end for the high-grade serous subtype, so frequent with mutation carriers. Thus, for these at-risk women, reluctant to RRSO, the idea of a temporary prophylactic surgery, limited to a bilateral radical fimbriectomy until oophorectomy at menopause, is being assessed in a prospective study. Meanwhile, due to these informations, it is advocated as well to perform salpingectomies in non-at-risk patients, candidates for a conservative hysterectomy or a surgical tubal ligation, as a primary prophylaxis of this dreadful disease.Les carcinomes ovariens héréditaires représentent environ 10 % des 4 500 nouveaux carcinomes ovariens annuels. Ils sont généralement liés à des mutations sur les gènes BRCA (1 ou 2) ou, à un moindre degré, sur ceux impliqués dans le syndrome HNPCC. En raison d’un dépistage insuffisamment efficace à ce jour, et du haut risque pour ces femmes de développer cette redoutable maladie, il est recommandé, après consultation d’oncogénétique, de procéder dès que possible à une annexectomie bilatérale prophylactique. Toutefois, certaines n’acceptent pas les conséquences de cette castration précoce, spécialement dans les cas où le traitement substitutif ne peut être délivré. Ce faisant, elles s’exposent à un risque croissant avec le temps de voir se développer cette maladie. Des données récentes, issues de l’examen précis des spécimens d’annexectomie prophylactique, ont révélé une fréquence anormale d’anomalies histologiques développées au niveau des trompes alors que les ovaires sont normaux. Une compréhension nouvelle de la pathogenèse des carcinomes ovariens fait désormais jouer un rôle central à la trompe de Fallope, en particulier à son extrémité terminale le pavillon ou fimbria, dans la survenue des carcinomes de haut grade séreux pelviens, de loin les plus fréquents chez ces femmes à risque héréditaire. D’où l’idée de tester dans le cadre d’une étude contrôlée, pour celles qui seraient réticentes à la réalisation de l’annexectomie bilatérale dans la crainte des effets secondaires d’une ménopause précoce, l’efficacité d’une chirurgie prophylactique limitée dans un premier temps à l’exérèse des deux trompes, en attendant la ménopause naturelle pour effectuer l’ovariectomie bilatérale complémentaire