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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Išplitusio kiaušidžių vėžio BRCA1/2 genų mutacijų įvairovė ir jų prognozinė reikšmė ligos berecidyviam ir bendrajam pacienčių išgyvenamumui / BRCA1/2 mutation spectrum and its prognostic significance for progression-free and overall survival in advanced ovarian cancer

Rudaitis, Vilius 25 September 2014 (has links)
Bendrojoje populiacijoje 1 iš 72 moterų suserga kiaušidžių vėžiu ir 1 iš 95 moterų miršta nuo šios ligos. Tyrimų duomenys rodo, kad ligos eiga nėra priklausoma vien tik nuo klasikinių prognozinių rodiklių, tokių kaip histologinis naviko tipas, naviko diferenciacija, ligos stadija, taikytas gydymas.Prognozinių veiksnių paieška krypstą link genetinių veiksnių galinčių įtakoti ligos eigą. Literatūros duomenys apie klinikinę BRCA1/2 genų reikšmę yra kontroversiški – nuo visiškai bereikšmio iki ženkliai teigiamo poveikio ligos eigai prognoziniu požiūriu.. Mūsų tyrėjų grupės atlikto tyrimo tikslas buvo nustatyti BRCA1/2 genų mutacijų dažnį ir jų įvairovę tarp pacienčių, sergančių išplitusiu kiaušidžių vėžiu, ir įvertinti šių mutacijų įtaką berecidyviam ir bendrajam išgyvenamumui. Mes nustatėme , kad tarp pacienčių sergančių išplitusių epiteliniu kiaušidžių vėžiu buvo net 51,4 proc. BRCA 1/2 mutacijų genuose turinčių pacienčių. 98,2 proc. šių pacienčių sirgo serozine papiline adenokarcinoma. Šios histologinės formos kiaušidžių vėžio buvo ženkliai daugiau mutuotų BRCA1/2 genų pacienčių grupėje nei tarp pacienčių be mutacijų (p-0,029). Tyrimo metu nustatėme dažniausiai sutinkamą arba bendro protėvio BRCA 1 4035 delA mutaciją bei taip kad statistiškai reikšmingos įtakos sergančiųjų išplitusiu kiaušidžių vėžiu berecidyviam išgyvenamumui turi pacienčių amžius (p=0,005), BRCA1/2 genų mutacijos(p=0,049) bei operacijos apimtis (p<0,0001), o bendrajam išgyvenamumui – tik operacijos... [toliau žr. visą tekstą] / In general population 1 of 72 women develop ovarian cancer and to 1 of 95 women this disease is lethal. A great number of clinical trials have shown that the course of the disease is not dependent only on the classical prognostic indicators such as histological tumor type, tumor differentiation, stage of the disease or treatment modalities. More than two decades ago the first publications on heredity factors indicated similarity among the patients diagnosed ovarian malignancies and their first degree relatives. The first genetic autosomal dominant inheritance was determined in the high-risk cancer tumor suppressor BRCA1/2 genes. In spite of the abundant number of trials studying the BRCA1/2 genes role in breast and ovarian carcinogenesis still it is not sufficiently clear the influence of these genes for the disease prognosis. The aim of our conducted trial was to determine the BRCA1/2 genes prognostic significance for progression-free and overall survival in the event of advanced ovarian cancer. In case of advanced ovarian cancer the BRCA1/2 mutation frequency was 51,4 %. Among all determined BRCA1/2 gene mutations BRCA1 4035delA or founder mutation was most frequent. It amounted to 63.6%. Non-optimal cytoreduction (p<0,0001 ) , patients’ older age (p=0,005) and absence of BRCA1/2 mutations (p=0,049) are closely connected with a shorter PFS and OS. Only non-optimal cytoreduction was related to a shorter OS (p=0,010).
32

Tools and Strategies That a BRCA Positive Population Considers to be Useful in the Result Disclosure Process to Family Members

Snyder, Justine A., B.A. 24 September 2012 (has links)
No description available.
33

Borde jag ta bort mina bröst? : Aspekter som påverkar kvinnors beslutsfattande vid profylaktisk mastektomi / Should I remove my breasts? : Aspects influencing women's decision-making regarding prophylactic mastectomy

Abrahamsson, Anna, Carlsson, Lina January 2024 (has links)
Bakgrund: Bröstcancer är den vanligaste cancerdiagnosen och mutation av BRCA 1/2-gener ökar bröstcancerrisken. Drabbade kvinnor får information kring behandlingsstrategier vilka diskuteras med eventuella närstående samt vårdpersonal och grundlägger val av behandling. Kvinnors upplevelser av profylaktisk mastektomi påverkas av flera aspekter, och påvisar därmed vikten av sjuksköterskans kompetens inom omvårdnad. Syfte: Att sammanställa och syntetisera kvalitativ forskning som utforskat vad som påverkar kvinnors beslutsfattande vid profylaktisk mastektomi vid risk för bröstcancer eller vid befintlig ensidig bröstcancer. Metod: En litteraturöversikt med kvalitativ ansats utifrån 13 originalartiklar vilka analyserades med tematisk innehållsanalys. Resultat: Tre teman identifierades; ”Existentiella val”, ”Informationens betydelse” samt ”Kroppslig påverkan”. Temat ”Existentiella val” gav två subteman, ”Mastektomi som oroslindrande” samt ”Minska risk för (åter)insjuknande”. Ur temat ”Informationens betydelse” identifierades två subteman, ”Informationsbehov” samt ”Omgivningens erfarenheter/åsikter” och temat ”Kroppslig påverkan” resulterade i subtemana ”Synen på kropp och kvinnlighet” och ”Amning”.  Slutsats: Litteraturstudien påvisar kvinnors beslutsfattande avseende profylaktisk mastektomi såsom rädslor, otillräckligt anpassad information samt kroppsliga aspekter. Resultatet påvisar ett behov av vidare forskning avseende dessa kvinnors upplevelser för att ge en djupare förståelse och ökad kompetens inom vården för att möjliggöra en personcentrerad och holistisk vård. / Background: Breast cancer is the most common cancer diagnosis, and BRCA 1/2 gene mutations increases breast cancer risk. Affected women receive information about treatment strategies, which are discussed with relatives and healthcare professionals and lay the foundation for treatment choices. Women´s experiences of prophylactic mastectomy are affected by many aspects, highlighting the importance of nursing competence.  Aim: To synthesize qualitative research exploring aspects affecting women´s decision-making regarding prophylactic mastectomy in case of increased breast cancer risk or existing unilateral breast cancer.    Method: A literature review with a qualitative approach based on 13 original articles, analyzed using thematic content analysis.   Result: Three themes were identified; “Existential choices”, “The importance of information” and “Physical impact”. “Existential choices” resulted in the subthemes, “Mastectomy as anxiety reliever” and “Reducing the risk of (re)occurrence”. “The importance of information” presented the subthemes “Informational needs” and “The experiences/opinions of others”. “Physical impact” offered subthemes “View of body and femininity” and “Breastfeeding”.   Conclusion: Aspects influencing women's decision-making regarding prophylactic mastectomy were revealed, e.g. fears, information and physical aspects. The results indicate a need for further research to deepen understanding and enhance healthcare competence for person-centered and holistic care.
34

Étude cas témoin de la nutrition, du style de vie et du cancer du sein chez les femmes Canadiennes Françaises porteuses d’une mutation fondatrice sur un des gènes BRCA 1 ou BRCA 2

Houssaini, Najlaa 04 1900 (has links)
Le cancer du sein est une maladie multifactorielle, plusieurs facteurs socio-économiques, alimentaires ainsi que le style de vie ayant été incriminés dans son développement. Une mutation germinale sur un des gènes BRCA1 ou BRCA2 serait responsable d’une augmentation du risque de développer un cancer du sein de 50 à 80% chez les femmes porteuses d’une mutation sur BRCA1 ou BRCA2 par comparaison aux non- porteuses. Plusieurs études rapportant l’existence d’une association entre la fréquence des cancers du sein sporadiques, les habitudes alimentaires et le style de vie des femmes atteintes, ceci, nous a amené à nous interroger sur le rôle que pourrait jouer ces mêmes facteurs chez les femmes porteuses d’une mutation sur BRCA1 ou BRCA2. Pour répondre à cette question, nous avons effectué une étude cas-témoin. Nos quarante-quatre cas sont porteuses d’une mutation germinale parmi 6 des 14 mutations fondatrices sur BRCA1 et BRCA2 les plus fréquentes dans la population Canadienne Française. Elles sont issues d’une cohorte de plus de 1000 femmes Canadiennes Françaises atteintes de cancers du sein recrutées depuis 1994 et testées pour ces 6 mutations. Les témoins sont recrutés parmi des femmes de la population Canadienne Française, également porteuses d’une de ces six mutations fondatrices de BRCA1 ou BRCA2, mais indemnes de cancers. Quinze d’entre elles ont été recrutées dans les familles des cas de l’étude initiale. Vingt-neuf ont été recrutées à la clinique des cancers familiaux du CHUM, nous permettant ainsi de totaliser 44 témoins. Deux questionnaires ont été administrés aux cas et aux témoins. Le premier, dit Questionnaire de base, a servi à recenser les informations sociodémographiques et le style de vie, couvrant ainsi les deux années précédant la découverte du cancer du sein pour les cas et les deux années précédant la découverte de la mutation pour les témoins. Le deuxième questionnaire, Questionnaire de nutrition, a permis de colliger les informations sur les habitudes alimentaires durant la même période de recueil de données. Une association positive et significative entre le risque de cancer du sein et le niveau d’éducation a été observé parmi les sujets de niveau universitaire (>14 années d’étude) comparés aux sujets n’ayant pas dépassé le niveau d’études secondaires (<11 années d’études) [OR= 7,82; IC95% : (1,99-30,69); p=0,003]. Nous avons mis en évidence que le risque de cancer du sein augmentait lorsque les sujets atteignaient leur poids maximum à un âge avancé > 48 ans [OR = 4,27 ; IC 95% : (0,82-22,25)]. Nous avons montré que le risque du cancer du sein diminuait pour une durée d’allaitement supérieure à 7 mois par comparaison aux femmes n’ayant jamais allaité [OR= 0,35; IC 95% : (0,12-1,06)] mais cette association est non significative. Les porteuses qui pratiquent plus de 22,45 Met-h-sem d’activité physique modérée, comparativement à celles qui pratiquent moins de 11,45 Met-h-sem voient leur risque de cancer du sein diminué de 72% [OR=0,28- IC 95% : (0,08-0,95); p=0,04]. Celles qui pratiquent plus de 31,95 Met-h-sem d’activité physique totale comparativement à celles qui pratiquent moins de 16,40 Met-h-sem voient leur risque de cancer du sein réduit de 79 % [OR=0,21; IC 95% : (0,06-0,75); p= 0,02]. L’analyse des macro et micronutriments et des groupes alimentaires a démontré qu’une consommation de plus de 23,20 g/j d’acide gras monoinsaturés est responsable d’une augmentation du risque de cancer du sein de 6 fois par comparaison à une consommation inférieure à 17,08 g/j [OR=6,00; IC 95% : (0,97-37,02); p=0,05]. Une consommation de plus de 221,79 µg/j de vitamine K réduit le risque du cancer du sein de 83 % par comparaison à une consommation inférieure à 143,57 µg/j [OR= 0,17; IC95% : (0,05-0,61) ; p=0,007]. La consommation de fruits est associée à une réduction du risque de cancer du sein de 73% chez les porteuses de mutations qui en consomment plus de 563,31 g/j comparée à celles qui en consomment moins de 356,18 g/j [OR= 0,27; IC 95% : (0,07-1,01) ; p=0,05]. Nos résultats confortent l’hypothèse selon laquelle le style de vie et les habitudes alimentaires jouent un rôle dans le développement du cancer du sein chez les Canadiennes Françaises porteuses de mutations d’une des 6 mutations fondatrices de BRCA1 ou 2 étudiées. En effet, un niveau d’éducation élevé, un gain de poids sont associés à un risque élevé de développer un cancer du sein. De plus la pratique de l’allaitement et d’une activité physique modérée sont associées à une réduction de ce risque. Nous montrons aussi que la consommation d’acides gras monoinsaturés est responsable d’une augmentation du risque de ce cancer et que la consommation de vitamine K et de fruits permet de réduire ce risque. Nos résultats ouvrent une nouvelle voie de recherche par rapport au rôle de certains nutriments dans le développement du cancer du sein chez les porteuses de mutation d’un des gènes BRCA. Cette voie pourrait également être explorée chez les non porteuses. / Breast cancer is a multifactorial disease and several dietary and lifestyle factors have been implicated in the development of breast cancer. Women carriers of a BRCA1 or BRCA2 germline mutation have a lifetime risk of 50 to 80% to develop breast cancer compared with 11 % in non carriers. Several studies have reported the existence of an association between the incidence of sporadic breast cancers, dietary factors and lifestyle which lead us to investigate the effects of these factors on breast cancer risk in women carriers of a BRCA1 or BRCA2 mutation. We have carried out a case-control study among French Canadian women in Montreal. Cases were from a cohort of around 1000 women affected with breast cancer, recruited since 1994. We have identified 44 affected women who have been tested for BRCA1 and BRCA2 for six founders mutations in the French Canadian population. All these cases were carriers of one of the six mentioned mutations. Controls were also women carriers of one of these six in BRCA1 or BRCA2 mutations but, unaffected with cancers. Fifteen of them coming from the same families of the studied cases and twenty-nine were identified at the familial cancer clinic of the CHUM, resulting in a total of 44 controls. A core questionnaire was administered to both cases and controls to gather information on socio-demographic and lifestyle risk factors covering the two years preceding the diagnosis of breast cancer for cases and the two years before the discovery of the mutation for controls. A validated semi-quantitative food frequency questionnaire was administered to ascertain dietary intake corresponding to the same period of time for both cases and controls. A positive and significant association between breast cancer risk and higher education was observed among subjects with a universitary education (> 14 years of study) compared with subjects who had no more than high school education (<11 years of studies) [OR = 7.82, 95% CI :( 1.99-30.69), p = 0.003]. We have found that breast cancer risk increased when gene mutation carriers reached their maximum weight at age> 48 years [OR = 4.27; 95% CI (0.82-22.25)]. In this study it was observed that breast cancer risk in carriers decreased with more than 7 months breast feeding compared with no breastfeeding [OR = 0.35, 95% CI = (0.12-1.06)] but this association was not significant. Women who practiced more than 22.45 MET-hours per week of moderate physical activity, compared with those practicing less than 11.45 MET-hours per week had a cancer risk decreased by 72% [OR = 0,28 - 95% IC (0.08-0.95), p = 0.04]. Those who practiced more than 31.95 MET-hours per week of total physical activity compared with less than 16.40 showed a risk reduced of around 79% [OR = 0.21; 95% CI:(0.06-0.75), p = 0.02]. The analysis of macro and micro-nutrients and food groups showed that consumption of more than 23.20 g/d of monounsaturated fatty acid increased the risk of breast cancer significantly compared with a consumption of less than 17.08 g/d [OR = 6.00, 95% CI:(0.97-37.02), p = 0.05]. We also observed that an intake of more 221.79 mg/d of vitamin K reduced the risk of breast cancer by 83% compared with those consuming less than 143.57 mg/d [OR = 0.17, 95% (0.05-0.61), p = 0.007]. High intake of fruits was associated with a lower risk of breast cancer risk (73%) among carriers who consumed more than 563.31 g / d compared with less than 356.18 g/d [OR = 0.27; 95% CI :(0.07-1.01), p = 0.05]. The results of our study support the role of lifestyle and dietary habits in the aetiology of breast cancer among French Canadian with a BRCA1 or BRCA2 mutation. In general, we have observed that a high level of educational and weight gain increased the risk of breast cancer among gene mutation carriers, while breastfeeding and a moderate physical activity reduced this risk. Regarding food habits and nutrition, our results suggest that high intake of mono-unsaturated fatty acids increased the risk of breast cancer. The higher intake of vitamin K and fruits showed a protective role against breast cancer. In our knowledge, this is the first finding of the possible relationship between nutrition, lifestyle and risk of breast cancer among French Canadian carriers of BRCA1 or BRCA2 mutation. Due to the small sample size of our study, more investigations are needed in the future to clarify this relationship.
35

Chemo-enzymatische Werkzeuge zur Untersuchung von nicht-codierender RNA

Hesse, Marlen 30 March 2017 (has links)
Nicht-codierende RNAs sind ein bedeutender Bestandteil genregulatorischer Prozesse. Ihre Fehlregulierung wird mit zellulärer Dysfunktion und der Entstehung von Krankheiten in Zusammenhang gebracht. Ziel dieser Arbeit war die Entwicklung verschiedener Testsysteme zur Untersuchung nicht codierender RNAs mit dem Schwerpunkt microRNA (miRNA), precursor miRNA (pre-miRNA) und circular RNA (circRNA). Für eine Zyklisierung und Funktionalisierung von circRNA mittels Cu-katalysierter Click-Chemie zur Identifizierung zellulärer Interaktionspartner und zugehöriger Wirkmechanismen wurden die Termini linearer RNA-Template modifiziert. Mit Hilfe enzymatischer Techniken wie Transkription und Ligation konnte in vitro die Inkorporation Azid- und Alkin-funktionalisierter Nukleotid-Bausteine am 5‘- und 3‘-Terminus gezeigt werden. Zur Untersuchung der miRNA-Reifung in cellulo wurde die pre-miRNA-134 unter Verwendung chemo-enzymatischer Methoden mit einem Fluorophor/Quencher-Paar an den Termini ausgestattet. Durch intrazelluläre Reifung der gelabelten pre-miRNA mit einhergehender Fluoreszenzfreisetzung sollte die Visualisierung und damit die Lokalisierung des miRNA-Reifungsortes innerhalb von Neuronen realisiert werden. Zudem gelang die Entwicklung eines auf branched rolling-circle amplification (BRCA) basierenden Argonaute2(Ago2)-vermittelten Spaltungsassays. Ein Enzymkomplex aus rekombinantem, humanem Ago2 und der miRNA miR 122, genannt minimal RISC, wurde dabei zur Substrat-Spaltung eingesetzt. Zur Etablierung des BRCA-basierenden Ago2-vermittelten Spaltungsassays als Screening-Tool für die Identifizierung potentieller Inhibitoren der mRNA-Spaltung wurden exemplarisch sechs Testsubstanzen aus der Gruppe der Aminoglykoside untersucht. Der BRCA-basierende Ago2-vermittelte Spaltungsassay stellte eine einfache und zuverlässige Detektionsmethode dar, der die Untersuchung einer größeren Probenzahl mit geringem Aufwand und ohne Verwendung von fluorogen gelabeltem Substrat ermöglichte. / Non-coding RNAs are an important factor in gene regulation in which their deregulation is associated with cellular dysfunction and disease. Here, the development of different test systems for the investigation of non-coding RNAs, namely microRNA (miRNA), precursor miRNA (pre-miRNA), and circular RNA (circRNA), was on focus. In order to circularize and functionalize circRNA with the purpose of identifying cellular interaction partners and possible mechanisms of action, 5‘- and 3‘-terminal modifications were added to a linear RNA template. This was accomplished by using azide- and alkyne-functionalized nucleotides which were incorporated by enzymatic approaches like transcription and ligation to be followed by Cu-catalyzed click chemistry for circularization. For investigating miRNA maturation in neuronal cells, pre-miR-134 was modified by chemo-enzymatic approach with fluorophore and quencher at its 5‘ and 3‘ ends, respectively. Intracellular maturation of labeled pre-miRNA would produce a fluorescent signal upon cleavage, thus enabling visualization and localization of miRNA maturation in neuronal cells. Furthermore, the development of Ago2-mediated mRNA cleavage assay based on branched rolling-circle amplification (BRCA) was accomplished. A complex of recombinant human Ago2 and miRNA miR-122, called minimal RISC, was used for substrate cleavage. To establish this assay as adequate screening method for identifying potential inhibitors of mRNA cleavage, a group of six aminoglycosides was tested. The BRCA-based Ago2-mediated cleavage assay showed to be a simple and reliable detection method and screening tool for small molecule binders with little effort and without fluorescent labeling of substrate.
36

Caracterização do impacto dos regimes quimioterápicos na reserva ovariana de pacientes com câncer de mama / The impact of adjuvant breast cancer chemotherapy on ovarian reserve and menses

Giuliano Marchetti Bedoschi 24 October 2018 (has links)
Parte das mulheres com câncer de mama na menacme gostariam de tentar preservar sua fertilidade após o tratamento oncológico. Entretanto, as informações disponíveis sobre a extensão do dano aos ovários após o tratamento quimioterápico são insuficientes para estimar o risco de comprometimento da reserva ovariana. Dessa forma, como objetivo primário deste estudo propusemos caracterizar o impacto dos regimes quimioterápicos mais comumente utilizados no tratamento do câncer de mama em mulheres na menacme sobre a reserva ovariana avaliada por meio da aferição das concentrações séricas de hormônio antiMulleriano (HAM) e calendário menstrual, analisados antes e um ano após o término da quimioterapia. Cento e trinta e quatro pacientes foram analisadas para o objetivo primário do estudo. As concentrações séricas de HAM foram dosadas por meio do teste ELISA e foram representadas pela mediana e intervalo interquartil. Os testes não paramétricos de MannWhitney e de Kruskal-Wallis foram utilizados para comparar as medidas de HAM em relação as variáveis categóricas. A idade média foi de 36,67 anos (DP 3,95), sendo que 104 mulheres realizaram quimioterapia com regime antracíclico (AC-T), 13 regime não antracíclico (CMF) e 17 outros regimes quimioterápicos. Os níveis de HAM após 1 ano do término da quimioterapia reduziram de maneira significativa (mediana 0,13 ng/ml, intervalo interquartil 0,02; 0,35 ng/ml) quando comparados aos níveis basais (mediana 2,84 ng/ml, intervalo interquartil 1,26; 4,65 ng/ml; p<0,0001). Apesar da redução significativa dos níveis de HAM, 74,7% das mulheres apresentavam ciclos menstruais um ano após o término da quimioterapia. O tipo de regime quimioterápico influenciou de maneira significativa a redução dos níveis do HAM após 1 ano do término da quimioterapia. O grupo de tratamento que utilizou CMF apresentou maior redução da reserva ovariana quando comparado com o grupo de tratamento que utilizou outros regimes quimioterápicos. O uso adjuvante de tamoxifeno não alterou os níveis de HAM aferidos após 1 ano do término do tratamento quimioterápico. As concentrações séricas de HAM basais (p<0,0001), a idade (p=0,0438) e o regime de tratamento realizado (p=0,0259) foram relacionados com a redução dos níveis de HAM após um ano do término da quimioterapia. Mulheres com mutações BRCA apresentam menores concentrações basais de HAM e menores taxas de recuperação ovariana após otérmino do tratamento quimioterápico quando comparadas a mulheres sem a mutação e mulheres não testadas por apresentarem baixo risco de mutação. Esse estudo longitudinal demonstrou que o tratamento quimioterápico promoveu redução significativa das concentrações séricas de HAM um ano após o término do tratamento. O fato da maioria das pacientes apresentar ciclos menstruais, apesar dos baixos níveis de HAM, sugere que a presença de menstruação não é um marcador acurado de reserva ovariana. O tipo de regime quimioterápico utilizado no tratamento oncológico demonstrou influenciar o comprometimento da reserva ovariana. O tratamento adjuvante com tamoxifeno parece não exacerbar o comprometimento da reserva ovariana. Demonstramos que a idade, os níveis basais de HAM e o tipo de regime quimioterápico são os fatores de predição mais importantes da reserva ovariana após o tratamento citotóxico. Sendo assim, geramos o primeiro nomograma para predizer o impacto da quimioterapia na reserva ovariana. O nomograma descrito deve ser validado prospectivamente em novos estudos. Além disso, a presença de mutações BRCA pode colocar as mulheres em desvantagem reprodutiva quando expostas ao estresse genotóxico. Essas informações podem ser utilizadas para aconselhamento individual de mulheres em idade reprodutiva em relação a necessidade de tratamentos para tentativa de preservação da fertilidade. / Some women of reproductive age diagnosed with breast cancer wish to preserve their fertility and ovarian function after their oncological treatment. However, information available on the likelihood and extent of ovarian damage from chemotherapy is insufficient to predict the risk of ovarian reserve damage for individual women. Thus, the primary goal of this study is to delineate the extent of ovarian damage from chemotherapeutic treatment regimens by using serum AMH and menstrual calendars analyzed before and one year after the end of chemotherapy treatment. A prospective longitudinal IRB-approved study was performed. One hundred and thirty-four patients fulfilled the eligibility criteria and accepted to participate in the study, presenting blood samples with AMH measurement before and after one year of chemotherapy treatment. Serum AMH concentrations were measured by ELISA and were represented by median and interquartile range. The nonparametric tests of MannWhitney and Kruskal-Wallis were used to compare AMH concentrations in relation to the categorical variables. The mean age was 36.67 years (SD 3.95), and 104 women underwent chemotherapeutic regimen with anthracyclic regimen (AC-T), 13 non-anthracyclic regimen (CMF) and 17 other chemotherapeutic regimens. In the 134 women analyzed, the AMH levels after 1 year of chemotherapy were significantly reduced (median 0.13 ng/ml, interquartile range 0.02; 0.35 ng/ml) when compared to levels before chemotherapy (median 2.84 ng/ml, interquartile range 1.26; 4.65 ng/ml; p<0.0001). Despite the significant reduction in AMH levels, 74.7% of the women had return of menses by 1-year post treatment. The treatment regimen significantly influenced the reduction of AMH levels after 1-year post chemotherapy treatment. The CMF treatment group demonstrated a greater ovarian reserve reduction when compared to other chemotherapeutic regimens treatment group. Our study did not show statistical difference when other comparisons were made between the treatment groups. In addition, adjuvant tamoxifen use did not alter AMH levels 1-year post chemotherapy. Mixed effect model analysis confirmed that, for all the analyzed women (N=134), baseline serum AMH levels (p<0.0001), age (p=0.0438), and regimen (p=0.0259) were related to the reduction in AMH levels 1-year after chemotherapy treatment. Women treated for breast cancer with BRCA mutations have lower baseline serum AMH levels and lower rates of ovarian recovery after chemotherapy treatment compared to non-mutatedwomen and untested women with low risk of mutation. This longitudinal study demonstrated that chemotherapy regimens commonly used in the treatment of breast cancer in postmenopausal women significantly reduced serum concentrations of AMH 1-year after the end of treatment, suggesting a significant impairment of the ovarian reserve. The fact that most of the patients present menstrual cycles, despite the low levels of AMH, suggests that the presence of menstruation is not an accurate marker of ovarian reserve. The type of chemotherapy regimen used in oncological treatment has been shown to influence the ovarian reserve impairment. Adjuvant treatment with tamoxifen does not exacerbate the impairment of the chemotherapy-induced damage to ovarian reserve. We have shown that age, baseline AMH levels, and type of chemotherapy regimen are the most important predictors of ovarian reserve after cytotoxic treatment. In addition, we generated the first nomogram to predict the impact of chemotherapy on ovarian reserve in women diagnosed with breast cancer at reproductive age who will undergo chemotherapy. The nomogram described should be prospectively validated in new studies. In addition, the presence of mutations in BRCA may place women at reproductive disadvantage when exposed to genotoxic stress. These findings have significant bearing both on fertility preservation counseling as well as reproductive aging research and treatment.
37

Caracterização do impacto dos regimes quimioterápicos na reserva ovariana de pacientes com câncer de mama / The impact of adjuvant breast cancer chemotherapy on ovarian reserve and menses

Bedoschi, Giuliano Marchetti 24 October 2018 (has links)
Parte das mulheres com câncer de mama na menacme gostariam de tentar preservar sua fertilidade após o tratamento oncológico. Entretanto, as informações disponíveis sobre a extensão do dano aos ovários após o tratamento quimioterápico são insuficientes para estimar o risco de comprometimento da reserva ovariana. Dessa forma, como objetivo primário deste estudo propusemos caracterizar o impacto dos regimes quimioterápicos mais comumente utilizados no tratamento do câncer de mama em mulheres na menacme sobre a reserva ovariana avaliada por meio da aferição das concentrações séricas de hormônio antiMulleriano (HAM) e calendário menstrual, analisados antes e um ano após o término da quimioterapia. Cento e trinta e quatro pacientes foram analisadas para o objetivo primário do estudo. As concentrações séricas de HAM foram dosadas por meio do teste ELISA e foram representadas pela mediana e intervalo interquartil. Os testes não paramétricos de MannWhitney e de Kruskal-Wallis foram utilizados para comparar as medidas de HAM em relação as variáveis categóricas. A idade média foi de 36,67 anos (DP 3,95), sendo que 104 mulheres realizaram quimioterapia com regime antracíclico (AC-T), 13 regime não antracíclico (CMF) e 17 outros regimes quimioterápicos. Os níveis de HAM após 1 ano do término da quimioterapia reduziram de maneira significativa (mediana 0,13 ng/ml, intervalo interquartil 0,02; 0,35 ng/ml) quando comparados aos níveis basais (mediana 2,84 ng/ml, intervalo interquartil 1,26; 4,65 ng/ml; p<0,0001). Apesar da redução significativa dos níveis de HAM, 74,7% das mulheres apresentavam ciclos menstruais um ano após o término da quimioterapia. O tipo de regime quimioterápico influenciou de maneira significativa a redução dos níveis do HAM após 1 ano do término da quimioterapia. O grupo de tratamento que utilizou CMF apresentou maior redução da reserva ovariana quando comparado com o grupo de tratamento que utilizou outros regimes quimioterápicos. O uso adjuvante de tamoxifeno não alterou os níveis de HAM aferidos após 1 ano do término do tratamento quimioterápico. As concentrações séricas de HAM basais (p<0,0001), a idade (p=0,0438) e o regime de tratamento realizado (p=0,0259) foram relacionados com a redução dos níveis de HAM após um ano do término da quimioterapia. Mulheres com mutações BRCA apresentam menores concentrações basais de HAM e menores taxas de recuperação ovariana após otérmino do tratamento quimioterápico quando comparadas a mulheres sem a mutação e mulheres não testadas por apresentarem baixo risco de mutação. Esse estudo longitudinal demonstrou que o tratamento quimioterápico promoveu redução significativa das concentrações séricas de HAM um ano após o término do tratamento. O fato da maioria das pacientes apresentar ciclos menstruais, apesar dos baixos níveis de HAM, sugere que a presença de menstruação não é um marcador acurado de reserva ovariana. O tipo de regime quimioterápico utilizado no tratamento oncológico demonstrou influenciar o comprometimento da reserva ovariana. O tratamento adjuvante com tamoxifeno parece não exacerbar o comprometimento da reserva ovariana. Demonstramos que a idade, os níveis basais de HAM e o tipo de regime quimioterápico são os fatores de predição mais importantes da reserva ovariana após o tratamento citotóxico. Sendo assim, geramos o primeiro nomograma para predizer o impacto da quimioterapia na reserva ovariana. O nomograma descrito deve ser validado prospectivamente em novos estudos. Além disso, a presença de mutações BRCA pode colocar as mulheres em desvantagem reprodutiva quando expostas ao estresse genotóxico. Essas informações podem ser utilizadas para aconselhamento individual de mulheres em idade reprodutiva em relação a necessidade de tratamentos para tentativa de preservação da fertilidade. / Some women of reproductive age diagnosed with breast cancer wish to preserve their fertility and ovarian function after their oncological treatment. However, information available on the likelihood and extent of ovarian damage from chemotherapy is insufficient to predict the risk of ovarian reserve damage for individual women. Thus, the primary goal of this study is to delineate the extent of ovarian damage from chemotherapeutic treatment regimens by using serum AMH and menstrual calendars analyzed before and one year after the end of chemotherapy treatment. A prospective longitudinal IRB-approved study was performed. One hundred and thirty-four patients fulfilled the eligibility criteria and accepted to participate in the study, presenting blood samples with AMH measurement before and after one year of chemotherapy treatment. Serum AMH concentrations were measured by ELISA and were represented by median and interquartile range. The nonparametric tests of MannWhitney and Kruskal-Wallis were used to compare AMH concentrations in relation to the categorical variables. The mean age was 36.67 years (SD 3.95), and 104 women underwent chemotherapeutic regimen with anthracyclic regimen (AC-T), 13 non-anthracyclic regimen (CMF) and 17 other chemotherapeutic regimens. In the 134 women analyzed, the AMH levels after 1 year of chemotherapy were significantly reduced (median 0.13 ng/ml, interquartile range 0.02; 0.35 ng/ml) when compared to levels before chemotherapy (median 2.84 ng/ml, interquartile range 1.26; 4.65 ng/ml; p<0.0001). Despite the significant reduction in AMH levels, 74.7% of the women had return of menses by 1-year post treatment. The treatment regimen significantly influenced the reduction of AMH levels after 1-year post chemotherapy treatment. The CMF treatment group demonstrated a greater ovarian reserve reduction when compared to other chemotherapeutic regimens treatment group. Our study did not show statistical difference when other comparisons were made between the treatment groups. In addition, adjuvant tamoxifen use did not alter AMH levels 1-year post chemotherapy. Mixed effect model analysis confirmed that, for all the analyzed women (N=134), baseline serum AMH levels (p<0.0001), age (p=0.0438), and regimen (p=0.0259) were related to the reduction in AMH levels 1-year after chemotherapy treatment. Women treated for breast cancer with BRCA mutations have lower baseline serum AMH levels and lower rates of ovarian recovery after chemotherapy treatment compared to non-mutatedwomen and untested women with low risk of mutation. This longitudinal study demonstrated that chemotherapy regimens commonly used in the treatment of breast cancer in postmenopausal women significantly reduced serum concentrations of AMH 1-year after the end of treatment, suggesting a significant impairment of the ovarian reserve. The fact that most of the patients present menstrual cycles, despite the low levels of AMH, suggests that the presence of menstruation is not an accurate marker of ovarian reserve. The type of chemotherapy regimen used in oncological treatment has been shown to influence the ovarian reserve impairment. Adjuvant treatment with tamoxifen does not exacerbate the impairment of the chemotherapy-induced damage to ovarian reserve. We have shown that age, baseline AMH levels, and type of chemotherapy regimen are the most important predictors of ovarian reserve after cytotoxic treatment. In addition, we generated the first nomogram to predict the impact of chemotherapy on ovarian reserve in women diagnosed with breast cancer at reproductive age who will undergo chemotherapy. The nomogram described should be prospectively validated in new studies. In addition, the presence of mutations in BRCA may place women at reproductive disadvantage when exposed to genotoxic stress. These findings have significant bearing both on fertility preservation counseling as well as reproductive aging research and treatment.
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Étude cas témoin de la nutrition, du style de vie et du cancer du sein chez les femmes Canadiennes Françaises porteuses d’une mutation fondatrice sur un des gènes BRCA 1 ou BRCA 2

Houssaini, Najlaa 04 1900 (has links)
Le cancer du sein est une maladie multifactorielle, plusieurs facteurs socio-économiques, alimentaires ainsi que le style de vie ayant été incriminés dans son développement. Une mutation germinale sur un des gènes BRCA1 ou BRCA2 serait responsable d’une augmentation du risque de développer un cancer du sein de 50 à 80% chez les femmes porteuses d’une mutation sur BRCA1 ou BRCA2 par comparaison aux non- porteuses. Plusieurs études rapportant l’existence d’une association entre la fréquence des cancers du sein sporadiques, les habitudes alimentaires et le style de vie des femmes atteintes, ceci, nous a amené à nous interroger sur le rôle que pourrait jouer ces mêmes facteurs chez les femmes porteuses d’une mutation sur BRCA1 ou BRCA2. Pour répondre à cette question, nous avons effectué une étude cas-témoin. Nos quarante-quatre cas sont porteuses d’une mutation germinale parmi 6 des 14 mutations fondatrices sur BRCA1 et BRCA2 les plus fréquentes dans la population Canadienne Française. Elles sont issues d’une cohorte de plus de 1000 femmes Canadiennes Françaises atteintes de cancers du sein recrutées depuis 1994 et testées pour ces 6 mutations. Les témoins sont recrutés parmi des femmes de la population Canadienne Française, également porteuses d’une de ces six mutations fondatrices de BRCA1 ou BRCA2, mais indemnes de cancers. Quinze d’entre elles ont été recrutées dans les familles des cas de l’étude initiale. Vingt-neuf ont été recrutées à la clinique des cancers familiaux du CHUM, nous permettant ainsi de totaliser 44 témoins. Deux questionnaires ont été administrés aux cas et aux témoins. Le premier, dit Questionnaire de base, a servi à recenser les informations sociodémographiques et le style de vie, couvrant ainsi les deux années précédant la découverte du cancer du sein pour les cas et les deux années précédant la découverte de la mutation pour les témoins. Le deuxième questionnaire, Questionnaire de nutrition, a permis de colliger les informations sur les habitudes alimentaires durant la même période de recueil de données. Une association positive et significative entre le risque de cancer du sein et le niveau d’éducation a été observé parmi les sujets de niveau universitaire (>14 années d’étude) comparés aux sujets n’ayant pas dépassé le niveau d’études secondaires (<11 années d’études) [OR= 7,82; IC95% : (1,99-30,69); p=0,003]. Nous avons mis en évidence que le risque de cancer du sein augmentait lorsque les sujets atteignaient leur poids maximum à un âge avancé > 48 ans [OR = 4,27 ; IC 95% : (0,82-22,25)]. Nous avons montré que le risque du cancer du sein diminuait pour une durée d’allaitement supérieure à 7 mois par comparaison aux femmes n’ayant jamais allaité [OR= 0,35; IC 95% : (0,12-1,06)] mais cette association est non significative. Les porteuses qui pratiquent plus de 22,45 Met-h-sem d’activité physique modérée, comparativement à celles qui pratiquent moins de 11,45 Met-h-sem voient leur risque de cancer du sein diminué de 72% [OR=0,28- IC 95% : (0,08-0,95); p=0,04]. Celles qui pratiquent plus de 31,95 Met-h-sem d’activité physique totale comparativement à celles qui pratiquent moins de 16,40 Met-h-sem voient leur risque de cancer du sein réduit de 79 % [OR=0,21; IC 95% : (0,06-0,75); p= 0,02]. L’analyse des macro et micronutriments et des groupes alimentaires a démontré qu’une consommation de plus de 23,20 g/j d’acide gras monoinsaturés est responsable d’une augmentation du risque de cancer du sein de 6 fois par comparaison à une consommation inférieure à 17,08 g/j [OR=6,00; IC 95% : (0,97-37,02); p=0,05]. Une consommation de plus de 221,79 µg/j de vitamine K réduit le risque du cancer du sein de 83 % par comparaison à une consommation inférieure à 143,57 µg/j [OR= 0,17; IC95% : (0,05-0,61) ; p=0,007]. La consommation de fruits est associée à une réduction du risque de cancer du sein de 73% chez les porteuses de mutations qui en consomment plus de 563,31 g/j comparée à celles qui en consomment moins de 356,18 g/j [OR= 0,27; IC 95% : (0,07-1,01) ; p=0,05]. Nos résultats confortent l’hypothèse selon laquelle le style de vie et les habitudes alimentaires jouent un rôle dans le développement du cancer du sein chez les Canadiennes Françaises porteuses de mutations d’une des 6 mutations fondatrices de BRCA1 ou 2 étudiées. En effet, un niveau d’éducation élevé, un gain de poids sont associés à un risque élevé de développer un cancer du sein. De plus la pratique de l’allaitement et d’une activité physique modérée sont associées à une réduction de ce risque. Nous montrons aussi que la consommation d’acides gras monoinsaturés est responsable d’une augmentation du risque de ce cancer et que la consommation de vitamine K et de fruits permet de réduire ce risque. Nos résultats ouvrent une nouvelle voie de recherche par rapport au rôle de certains nutriments dans le développement du cancer du sein chez les porteuses de mutation d’un des gènes BRCA. Cette voie pourrait également être explorée chez les non porteuses. / Breast cancer is a multifactorial disease and several dietary and lifestyle factors have been implicated in the development of breast cancer. Women carriers of a BRCA1 or BRCA2 germline mutation have a lifetime risk of 50 to 80% to develop breast cancer compared with 11 % in non carriers. Several studies have reported the existence of an association between the incidence of sporadic breast cancers, dietary factors and lifestyle which lead us to investigate the effects of these factors on breast cancer risk in women carriers of a BRCA1 or BRCA2 mutation. We have carried out a case-control study among French Canadian women in Montreal. Cases were from a cohort of around 1000 women affected with breast cancer, recruited since 1994. We have identified 44 affected women who have been tested for BRCA1 and BRCA2 for six founders mutations in the French Canadian population. All these cases were carriers of one of the six mentioned mutations. Controls were also women carriers of one of these six in BRCA1 or BRCA2 mutations but, unaffected with cancers. Fifteen of them coming from the same families of the studied cases and twenty-nine were identified at the familial cancer clinic of the CHUM, resulting in a total of 44 controls. A core questionnaire was administered to both cases and controls to gather information on socio-demographic and lifestyle risk factors covering the two years preceding the diagnosis of breast cancer for cases and the two years before the discovery of the mutation for controls. A validated semi-quantitative food frequency questionnaire was administered to ascertain dietary intake corresponding to the same period of time for both cases and controls. A positive and significant association between breast cancer risk and higher education was observed among subjects with a universitary education (> 14 years of study) compared with subjects who had no more than high school education (<11 years of studies) [OR = 7.82, 95% CI :( 1.99-30.69), p = 0.003]. We have found that breast cancer risk increased when gene mutation carriers reached their maximum weight at age> 48 years [OR = 4.27; 95% CI (0.82-22.25)]. In this study it was observed that breast cancer risk in carriers decreased with more than 7 months breast feeding compared with no breastfeeding [OR = 0.35, 95% CI = (0.12-1.06)] but this association was not significant. Women who practiced more than 22.45 MET-hours per week of moderate physical activity, compared with those practicing less than 11.45 MET-hours per week had a cancer risk decreased by 72% [OR = 0,28 - 95% IC (0.08-0.95), p = 0.04]. Those who practiced more than 31.95 MET-hours per week of total physical activity compared with less than 16.40 showed a risk reduced of around 79% [OR = 0.21; 95% CI:(0.06-0.75), p = 0.02]. The analysis of macro and micro-nutrients and food groups showed that consumption of more than 23.20 g/d of monounsaturated fatty acid increased the risk of breast cancer significantly compared with a consumption of less than 17.08 g/d [OR = 6.00, 95% CI:(0.97-37.02), p = 0.05]. We also observed that an intake of more 221.79 mg/d of vitamin K reduced the risk of breast cancer by 83% compared with those consuming less than 143.57 mg/d [OR = 0.17, 95% (0.05-0.61), p = 0.007]. High intake of fruits was associated with a lower risk of breast cancer risk (73%) among carriers who consumed more than 563.31 g / d compared with less than 356.18 g/d [OR = 0.27; 95% CI :(0.07-1.01), p = 0.05]. The results of our study support the role of lifestyle and dietary habits in the aetiology of breast cancer among French Canadian with a BRCA1 or BRCA2 mutation. In general, we have observed that a high level of educational and weight gain increased the risk of breast cancer among gene mutation carriers, while breastfeeding and a moderate physical activity reduced this risk. Regarding food habits and nutrition, our results suggest that high intake of mono-unsaturated fatty acids increased the risk of breast cancer. The higher intake of vitamin K and fruits showed a protective role against breast cancer. In our knowledge, this is the first finding of the possible relationship between nutrition, lifestyle and risk of breast cancer among French Canadian carriers of BRCA1 or BRCA2 mutation. Due to the small sample size of our study, more investigations are needed in the future to clarify this relationship.
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Les dysplasies tubo-ovariennes : contribution à une meilleure compréhension de la carcinogenèse ovarienne / Ovarian and tubal dysplasia : an early event in the pathogenesis of epithelial ovarian cancer

Chêne, Gautier 14 June 2011 (has links)
Introduction : l’analyse histopathologique des pièces d’annexectomie prophylactique(pBSO) pour risque génétique (mutations BRCA) a pu révéler des anomalies cytologiques etarchitecturales interprétées comme potentiellement pré-cancéreuses et dénommées « dysplasieovarienne et tubaire ». Nous proposons d’étudier les aspects morphologiques,immunohistochimiques et moléculaires des dysplasies tubo-ovariennes.Matériels & Méthodes : l’analyse morphologique a été réalisée dans un premier grouped’annexectomies après stimulation de l’ovulation (protocole de Fécondation in vitro).L’évaluation morphologique et immunohistochimique (expression de Ki67, p53, Bcl2, PAX2et ALDH1) a par la suite concerné 111pBSO, 42 annexectomies exposées au Tamoxifène et116 témoins non cancéreux et spontanément fertiles (nBSO). Les analyses ont été réaliséespar deux pathologistes en aveugle. Les cellules épithéliales d’intérêt ovariennes et tubairesprovenant du groupe pBSO ont été microdisséquées par laser ; l’ADN extrait a été étudié parhybridation génomique comparative (CGH array). La longueur des télomères a été évaluéepar PCR quantitative en temps réel.Résultats : les scores moyens de dysplasie ovarienne et tubaire étaient significativement plusélevés dans les groupes stimulation de l’ovulation et génétique par rapport aux témoins. Seulle score de dysplasie tubaire était supérieur aux témoins pour le groupe Tamoxifène. Onretrouvait une surexpression de ALDH1 dans les groupes pBSO et tBSO alors que Ki67, p53,bcl2 et PAX2 étaient faiblement exprimés dans les groupes pBSO et tBSO. D’ailleurs,l’expression d’ALDH1 était faible dans l’épithélium non dysplasique, forte dans la dysplasieet constamment faible dans les carcinomes occultes. De subtiles altérations génomiques et desraccourcissements télomériques ont été mis en évidence au niveau des dysplasies génétiques.Conclusions : les scores élevés de dysplasie, la forte expression d’ALDH1 et les altérationsmoléculaires provenant du groupe à risque génétique pourraient supporter le conceptd’instabilité génétique. La dysplasie tubo-ovarienne pourrait être une étape importante etprécoce de la carcinogenèse ovarienne. Nos résultats suggèrent également qu’un certainnombre de cancers de l’ovaire pourrait avoir pour origine la trompe de Fallope. Le marqueurde cellules souches ALDH1 pourrait constituer une cible dans la prévention et le diagnosticprécoce des cancers de l’ovaire. / Background: Histopathological examination of material from prophylactic salpingooophorectomies(pBSO) performed in patients at genetic risk has revealed frequentabnormalities interpreted as possible pre-cancerous “ovarian and tubal dysplasia” lesions. Wesought to study the morphologic, immunohistochemical and molecular features in ovarian andtubal dysplasiaMaterials and methods : Morphologic analysis was evaluated in 37 oophorectomies afterovulation induction (iBSO). Morphologic features and immunohistochemical expressionpatterns of Ki-67, p53, Bcl2, PAX2 and ALDH1 (an enzyme significantly associated withearly-stage ovarian cancer) were evaluated in 111 pBSO, 42 salpingo-oophorectomiesexposed with Tamosifen (tBSO) and 116 normal salpingo-oophorectomies (nBSO).Representative slides from formalin-fixed, paraffin-embedded tissue blocks were read blindlyby two gynaecological pathologists. Tubal and ovarian epitheliums from normal anddysplastic tissues (from pBSO) were laser microdissected and studied by comparativegenomic hybridization (array CGH). Telomere length was performed using quantitative realtimePCR.Results: Mean ovarian and tubal dysplasia score were significantly higher in the ovulationinduction group and in the genetic risk group than in controls. Only tubal dysplasia score wassignificantly higher in the Tamoxifen group. Increased ALDH1 expression was observed inpBSO and tBSO compared with nBSO whereas expression patterns of Ki67, p53, bcl2 andPAX2 were low at moderate in pBSO and tBSO group. Interestingly, ALDH1 expression waslow in non dysplastic epithelium, high in dysplasia and constantly low in the carcinoma foundincidentally on pBSO. Subtle genomic alterations were found in the dysplastic ovarian andtubal epitheliums. Shortened telomeres were found in dysplastic tissues from pBSO.Conclusion: The increased dysplasia scores, the strong ALDH1 expression and the geneticalterations in ovaries and tubes from BRCA 1/2 carriers could support the genetic instabilityof dysplasia and might be consistent with progression towards neoplastic transformation andcould justify the use of the term “dysplasia”. Ovarian and tubal dysplasia may be a premalignant,non-invasive histopathological abnormalitie that could be an important step in11early ovarian neoplasia. Our results suggest that a greater percentage of ovarian cancers thanoriginally thought may actually have a fallopian origin with metastasis to the ovary. The stemcell marker ALDH1 activation in pBSO could be considered as a target for early diagnosisand prevention of ovarian cancers.
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Régulation, par les microARNs, des gènes de prédisposition au cancer du sein BRCA / Regulation by microRNA of the breast cancer predisposition genes BRCA

Garcia, Amandine 29 September 2011 (has links)
Une absence ou une réduction de l’expression des gènes de prédisposition au cancer du sein BRCA1 et BRCA2 est retrouvée dans un tiers des cancers du sein sporadiques. Cependant, les mécanismes entraînant une inactivation de leur expression déjà identifiés comme la présence de mutations somatiques, l’hyperméthylation de leur promoteur ou encore la perte d’hétérozygotie (LOH) ne suffisent pas, à eux-seuls, à expliquer cette forte diminution. Nous avons donc émis l’hypothèse d’une régulation de l’expression des gènes BRCA par les microARNs (miR). Suite à une analyse bioinformatique, validée par des tests luciférase, nous avons montré l’interaction directe de miR-146a et miR-146b-5p avec la 3’UTR de BRCA1. Ces miRs diminuent le taux de protéine BRCA1 lors de leur surexpression et l’augmentent lors de leur inhibition. Nous avons montré également le rôle joué par ces miRs dans la prolifération cellulaire et dans la réparation par recombinaison homologue, fonctions pour lesquelles BRCA1 est requise. Nous avons retrouvé ces 2 miRs surexprimés dans les lignées mammaires et les tumeurs triple-négatives qui ont un profil semblable aux tumeurs développées chez les porteuses de mutations BRCA1. Dans une deuxième partie nous avons analysé si ces deux microARNs jouaient aussi un rôle dans les cancers du sein familiaux. Notre étude du SNP rs2910164 : G>C situé dans le gène de miR-146a, nous a permis de montrer que sa présence ne modifie pas le risque de développer un cancer du sein chez les porteuses de mutation BRCA1 et BRCA2. Nous avons également entrepris de rechercher si certains gènes codant pour des miRs pouvaient être de nouveaux gènes modificateurs du risque tumoral chez les porteuses BRCA, et/ou de nouveaux allèles de prédisposition au cancer du sein / An absence or a reduction of the expression of the BRCA1 and BRCA2 breast cancer predisposition genes is found in one third of sporadic breast cancers. However, the mechanisms leading to the inactivation of their expression that have been already identified like the presence of somatic mutations, hypermethylation of the promoter or loss of heterozygosity at the BRCA loci are not sufficient to explain this large diminution. We therefore hypothesised that the expression of the BRCA genes could be regulated by microRNAs (miR). Following a bioinformatics analysis, validated by luciferase tests, we have shown a direct interaction of miR-146a and miR-146-b-5p with the 3’UTR of BRCA1. These miRs decrease the BRCA1 protein rate when they are overexpressed and increase it when they are inhibited. Furthermore we have demonstrated the role played by these miRs in cell proliferation and DNA repair by homologous recombination, two mechanisms for which BRCA1 is required. We have found these two miRs overexpressed in mammary cell lines and in triple-negative breast tumors that have a profile similar to that of the tumors developed by BRCA1 mutation carriers. In a second part, we analysed if these two microRNAs also play a role in familial breast cancers. An association study of the rs2910164 : G>C SNP located in the gene for miR-146a, has permitted us to show that its presence does not seem to modify the risk to develop breast cancer in BRCA1 and BRCA2 mutation carriers. We have also undertaken to determine if some miR genes could modify tumor risk in BRCA mutation carriers, and/or could represent new breast cancer predisposing alleles

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