Nous avons étudié le transcriptome de neuf échantillons d'ARN extraits de cultures primaires de cellules non tumorales de l’épithélium de surface de l’ovaire (NOSE) provenant de quatre donneuses non porteuses de mutation, deux mutées sur BRCA1 et trois sur BRCA2, ainsi que de quatre échantillons d’ARN extraits de cultures primaires de cellules tumorales de l’ovaire (TOV) provenant de trois donneuses porteuses de mutation sur BRCA1 et une sur BRCA2. Nous avons identifié, pour la première fois, les signatures moléculaires associées à la présence d’une mutation de BRCA1 et BRCA2 dans les cellules NOSEs ainsi que la signature associée à la transformation tumorale des cellules NOSEs en TOVs chez les porteuses de mutation de BRCA1. Nous avons également localisé les domaines chromosomiques comportant des gènes corégulés en association avec la présence d’une mutation de BRCA1 dans les cellules NOSEs. Les allèles sauvage et muté de BRCA2 étaient exprimés dans les cellules TOVs provenant des porteuses de la mutation 8765delAG sur BRCA2. Nous avons observé que le niveau d’expression des transcrits de BRCA2 était plus élevé dans les cellules provenant des tumeurs ovariennes les plus agressives chez les femmes porteuses de la mutation 8765delAG sur BRCA2, les transcrits correspondants à l’allèle muté contribuant avec un pourcentage élevé du niveau d’expression total du gène. Le phénotype tumoral observé chez les Canadiennes Françaises porteuses de cette mutation pourrait résulter d’un effet de dosage de l’allèle muté. / We analyzed the transcriptome of nine primary cultures of non-tumor ovarian surface epithelium cells (NOSE) from four non-carriers, two BRCA1 and three BRCA2 carriers, and four primary cultures of tumor ovarian cells (TOV) from three BRCA1 and one BRCA2 carriers. We identified the first molecular signatures associated with the presence of BRCA1 and BRCA2 mutations in NOSEs and the first molecular signature associated with the transformation from NOSEs to TOVs in French Canadian women carriers of BRCA1 mutation. Moreover, we localized some co-regulated chromosomal domains associated with the presence of a BRCA1 mutation in NOSE cells. Wild-type and mutated BRCA2 allelic transcripts were expressed in tumor cells from 8765delAG BRCA2 mutation carriers, with the highest level of BRCA2 transcript expression and the highest contribution of the mutated allele in cells originating from the most aggressive ovarian tumors. The observed phenotype in BRCA2-mutated cells as well as the aggressiveness of the tumor could result from a dosage effect of the BRCA2 mutated allele.

Les femmes porteuses d'une mutation du gène BRCA1 ou BRCA2 ont un risque de cancer du sein (CS) très élevé dont les estimations varient beaucoup d'une étude à l'autre. L'objectif principal de cette étude est de mieux estimer le risque de CS associé aux gènes BRCA1/2 en tenant compte de la variabilité des mutations et des facteurs " environnementaux/style de vie " et de leur éventuelle interaction. Nous avons analysé les données de la cohorte GENEPSO composée de femmes porteuses d'une mutation du gène BRCA1 ou BRCA2 à l'aide d'un modèle de Cox pondéré. L'analyse des facteurs de risque gynéco-obstétrique et de " style de vie " a permis de mettre en évidence une association entre le risque de CS et les radiations ionisantes, la consommation de tabac, l'indice de masse corporelle, l'âge aux premières règles, la parité, les interruptions de grossesse, la contraception orale, la ménopause et les traitements hormonaux substitutifs. Cette étude confirme l'existence d'une zone centrale à moindre risque de CS dans les gènes BRCA1/2 et de décrire une nouvelle région à haut risque située dans la région 3' du gène BRCA2. Cette étude montre également une interaction entre la localisation des mutations et la parité ainsi que la ménopause. Cette étude montre l'importance de la prise en compte simultanée des facteurs de risque " non génétiques " et de la localisation des mutations dans les gènes BRCA1/2 dans l'estimation des risques de CS. Si nos résultats sont confirmés sur de plus larges données, cette étude pourrait aider ces femmes dans le choix du type de stratégie de surveillance ou de prévention le mieux adapté à leur situation.

Abstract The purpose of this study was to develop a hypothetical model of genetic counseling for male hereditary breast cancer mutation (BRCA1/2) carriers. The methodological approach involved mixed methods. The aim of the first phase was to describe male BRCA1/2 mutation carriers’ genetic counseling, experiences and needs for developing genetic counseling. Quantitative data were acquired using a patient counseling questionnaire (n=35) based on consecutive sampling, whereas theme-based interviews (n=31) were conducted as a qualitative approach. In the second phase, the theme-based interview data were used to describe males’ experiences after identification as BRCA1/2 mutation carriers and effects of identification as a carrier on their lives (n=31). The data were analyzed using descriptive statistics and inductive content analysis. The results of the study were combined into a model describing genetic counseling for male BRCA1/2 mutation carriers. Based on the quantitative data, the genetic counseling was evaluated as good. Psychosocial support was insufficient. According to the qualitative data, there was lack of noticing individual wishes and needs during the genetic counseling process. Operational conditions of departments of clinical genetics and genetic healthcare professionals’ readiness to provide gentic counseling were varied. Identification as a BRCA1/2 mutation carrier caused varied emotional reactions associated with identification as a carrier, hereditary transmission of the mutation, cancer risks and possibility of developing cancer. However, the duration of the reactions varied. Identification as a carrier had effects on male carriers’ health and social wellbeing. According to the hypothetical model, genetic counseling was based on the backgrounds and individual needs of the male BRCA1/2 mutation carriers, which was implemented with appropriate operational conditions. It included sufficient psychological support, which genetics healthcare professionals had professional responsibility for implementing. The information study provided can be used to broaden the knowledge base of nursing science in clinical genetics. The information may also be utilized in continued nursing education. / Tiivistelmä Tutkimuksen tarkoituksena oli kehittää periytyvän rintasyöpäalttiusmutaation (BRCA1/2) kantajamiesten hypoteettinen perinnöllisyysneuvontamalli. Tutkimuksessa käytettiin monimenetelmämetodologiaa. Ensimmäisessä vaiheessa kuvattiin BRCA1/2-alttiusmutaation kantajamiesten perinnöllisyysneuvontaa, perinnöllisyysneuvontakokemuksia ja kehittämistarpeita. Aineisto kerättiin kokonaisotannalla kvantitatiivisesti Potilasohjaus-kyselylomakkeella (n=35) ja kvalitatiivisesti teemahaastatteluilla (n=31). Toisessa vaiheessa kuvattiin ensimmäisessä vaiheessa kerätyllä haastatteluaineistolla kantajamiesten kokemuksia alttiusmutaation kantajuudesta ja kantajuuden vaikutuksista elämään (n=31). Tutkimuksen aineistot analysoitiin tilastollisin menetelmin ja induktiivisella sisällönanalyysillä. Tutkimuksen tulosten perusteella muodostettiin BRCA1/2-alttiusmutaation kantajamiesten perinnöllisyysneuvontamalli. Kvantitatiivisen tutkimuksen perusteella perinnöllisyysneuvonta arvioitiin hyväksi. Psykososiaalisen tuen saaminen oli vähäistä. Kvalitatiivisen tutkimuksen mukaan kantajamiesten yksilöllisten toiveiden ja tarpeiden huomioiminen perinnöllisyysneuvontaprosessin aikana oli puutteellista. Kliinisen genetiikan yksiköiden toimintaedellytyksissä ja perinnöllisyysneuvonnan antajien ohjausvalmiuksissa oli vaihtelevuutta. BRCA1/2-alttiusmutaation kantajuus aiheutti kantajamiehille eriasteisia ja -kestoisia emotionaalisia tunteita, jotka liittyivät kantajuuteen, alttiusmutaation periytymiseen, syöpäriskiin ja syöpään sairastumiseen. Kantajuudella oli lisäksi vaikutusta kantajamiesten terveydelliseen ja sosiaaliseen hyvinvointiin. Periytyvän rintasyöpäalttiusgeenin hypoteettisen mallin perusteella perinnöllisyysneuvonta oli BRCA1/2-alttiusmutaation kantajamiehen taustatilanteeseen ja yksilölliseen tarpeeseen perustuva neuvonta, joka oli toteutettu asianmukaisin toimintaedellytyksin. Se sisälsi riittävästi psykososiaalista tukea ja sen antajalla oli ammatillinen vastuu perinnöllisyysneuvonnan toteuttamisesta. Tutkimuksessa tuotetun tiedon avulla lisätään hoitotieteellistä tietoperustaa perinnöllisyyslääketieteen alueelle. Tietoa voidaan hyödyntää myös hoitotyön täydennyskoulutuksessa.

Abstract In Western countries, breast and ovarian cancer are among the most frequent malignancies affecting women. Approximately 5–10% of the cases in the general population have been suggested to be attributed to inherited disease susceptibility. BRCA1 and BRCA2 are the main genes associated with predisposition to breast and ovarian cancer. Mutations in these two genes explain a major part of the families displaying a large number of early-onset breast and/or ovarian cancers, but at least one third of the cases appear to be influenced by other, as yet unidentified genes. Therefore, it is likely that defects in other cancer predisposing genes, perhaps associated with lower disease penetrance and action in a polygenic context, will also be discovered. In the present study, the contribution of germline mutations in putative breast and/or ovarian cancer susceptibility genes, based on their biological function, has been investigated in Finnish breast cancer families. The role of large genomic deletions or other rearrangements in the BRCA1 and BRCA2 genes was evaluated by Southern blot analysis, and mutation analysis of TP53, RAD51, the BRC repeats of BRCA2, and 53BP1 was performed by conformation sensitive gel electrophoresis and DNA sequencing. Germline TP53 mutations were searched for in 108 Finnish breast cancer families without BRCA1 or BRCA2 alterations. In this study, the pathogenic TP53 germline mutation, Arg248Gln, was identified in only one family. This family showed a strong family history of breast cancer and other cancers also fulfilling the criteria for Li-Fraumeni-like syndrome. Germline TP53 mutations are expected to be found in cancer families with clinical features seen in Li-Fraumeni or Li-Fraumeni-like syndromes. In this study, large deletions in BRCA1 and BRCA2 were not observed in 82 breast and/or ovarian cancer families. Likewise, no disease-related aberrations were detected in RAD51, the BRC repeats of BRCA2 or 53BP1 in the 126 breast and/or ovarian cancer families studied. The obtained results were validated by comparing to the occurrence in 288–300 female cancer-free control individuals. These results do not support the hypothesis that alterations in these particular genomic regions play a significant role in breast cancer predisposition in Finland. Thus, there are still genes to be discovered to explain the molecular background of breast cancer.

No description available.

Inherited mutations in the BRCA2 gene predispose individuals to the development of breast and ovarian cancers. The BRCA2 protein plays a fundamental role in the repair of DNA double strand breaks by homologous recombination (HR). BRCA2 mediates the recruitment of the RAD51 recombinase to DNA damage sites, which in turn promotes homologous pairing and strand exchange during HR. It has been reported that increased BRCA2 mRNA levels correlate with poor cancer prognosis, and recently it has been shown that increased levels of BRCA2 suppress HR. As HR is regulated through the cell cycle and can only be employed during S and G2 phases of the cell cycle, in this study, the cell cycle-dependent regulation of BRCA2, as a key player of HR, was investigated. In this study I report that BRCA2 stability is regulated by the ubiquitin-proteasome system (UPS), which has become increasingly evident as an important regulator of DNA repair. In line with this, I found that BRCA2 can be ubiquitylated in vivo and that it interacts with proteins of the UPS. Interestingly, I observed that BRCA2 levels and its ubiquitylation status change during the cell cycle. Using a siRNA-based approach, I identified a candidate E3 ubiquitin ligase, the SCF^FBXW7 complex, which is also a known major cell cycle regulator. siRNA-mediated knockdown of FBXW7 led to stabilization of BRCA2 and overexpression of FBXW7 resulted in BRCA2 ubiquitylation in vivo. Furthermore, I have refined the regions that the SCF^FBXW7 interacts with on BRCA2, which likely occurs in a phosphorylation-dependent manner. Taken together, these observations suggest that BRCA2 stability is regulated by the UPS in a cell cycle-dependent manner, which may be an important regulatory mechanism for BRCA2 function.

Many breast cancer diagnoses and second cancers are associated with BRCA gene mutations. Early detection of cancer is necessary to improve health outcomes, particularly with second cancers. Little is known about the influence of risk factors on time to diagnosis of second primary cancers after diagnosis with BRCA-related breast cancer. The purpose of this cohort study was to examine the risk of diagnosis of second primary cancers among women diagnosed with breast cancer after adjusting for BRCA status, age, and ethnicity. The study was guided by the empirical evidence supporting the mechanism of action in the mutation of BRCA leading to the development of cancer. Composite endpoint was used to define second primary cancer occurrences, and Kaplan-Meier survival curves were used to compare the median time-to-event among comparison groups and BRCA gene mutation status. Cox proportional hazards was used to examine the relationships between age at diagnosis, ethnicity, BRCA gene mutation status, and diagnosis of a second primary cancer. The overall median time to event for diagnosis of second primary cancers was 14 years. The hazard ratios for BRCA2 = 1.47, 95% CI [1.03 - 2.11], White = 1.511, 95% CI [1.18 - 1.94], and American Indian/Hawaiian = 1.424, 95% CI [1.12 -1.81] showing positive significant associations between BRCA2 mutation status and risk of diagnosis of second primary colorectal, endometrial, cervical, kidney, thyroid, and bladder cancers. Data on risk factors for development of second cancers would allow for identification of appropriate and timely screening procedures, determining the best course of action for prevention and treatment, and improving quality of life among breast cancer survivors.

Thesis (Ph.D. in Experimental Pathology, Program in Cancer Biology) -- University of Colorado Denver, 2007. / Typescript. Includes bibliographical references (leaves 144-158). Free to UCD affiliates. Online version available via ProQuest Digital Dissertations;

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-04-17T23:12:48Z No. of bitstreams: 1 AnaRafaelaDeSouzaTimoteo_TESE.pdf: 3659954 bytes, checksum: d2c8b061166b6be5547b4452cf6fed7b (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-04-20T21:54:51Z (GMT) No. of bitstreams: 1 AnaRafaelaDeSouzaTimoteo_TESE.pdf: 3659954 bytes, checksum: d2c8b061166b6be5547b4452cf6fed7b (MD5) / Made available in DSpace on 2017-04-20T21:54:51Z (GMT). No. of bitstreams: 1 AnaRafaelaDeSouzaTimoteo_TESE.pdf: 3659954 bytes, checksum: d2c8b061166b6be5547b4452cf6fed7b (MD5) Previous issue date: 2016-12-12 / A S?ndrome de c?ncer de mama e ov?rio heredit?rio corresponde a 10-15% de todos os casos diagnosticados de c?ncer de mama no mundo. A maioria das muta??es germinativas s?o identificadas nos genes BRCA1 e BRCA2, contudo, a aplica??o de pain?is multig?nicos tem aumentado o n?mero de variantes patog?nicas detectadas em outros genes supressores de tumor. De acordo com a vers?o atual do protocolo americano NCCN (National Comprehensive Cancer Network), as muta??es em BRCA1 e BRCA2, TP53 e PTEN conferem alto risco de desenvolver c?ncer de mama, e muta??es em CDH1, CHEK2, PALB2, ATM e BRIP podem aumentar em 20% o risco para o desenvolvimento desta doen?a. Neste estudo foram analisados 157 indiv?duos com hist?rico pessoal e/ou familiar de c?ncer de mama. O DNA gen?mico foi isolado a partir de sangue perif?rico por meio de extra??o ? base de solu??o salina e as amostras foram analisadas usando o sequenciamento de nova gera??o (NGS). Foram identificadas 15 variantes patog?nicas e 4 VUS (Variants of Uncertain Significance) em 27 indiv?duos (27/157; 17%), dos quais tr?s s?o assintom?ticos. Foram identificadas sete novas variantes em 4 genes: BRCA1_c.3409A>G; BRCA2_g.26826_30318del, BRCA2_c.5800C>T; BRCA2_c.5228G>A; BRCA2_c.5305delG; ATM_c.634delT e ATR_c.3043C>T. Sessenta e oito por cento (13/19; 68%) de variantes foi detectada nos genes BRCA1 e BRCA2, enquanto 32% (6/19) foram identificados nos genes de risco moderado ATM (2/19); ATR (1/19); CDH1 (1/19); MLH1 (1/19) e MSH6 (1/19). Os indiv?duos foram separados em dois grupos para a an?lise comparativa: portadores de muta??o nos genes de alto risco e nos genes de risco moderado. Entre os tr?s indiv?duos assintom?ticos, duas variantes est?o presentes nos genes de risco moderado ATM e MLH1. Entre os indiv?duos com c?ncer de mama, dezoito pacientes (18/24; 75%) apresentaram muta??es em genes de alto risco, enquanto seis (6/24; 25%) s?o portadores de muta??es em genes de risco moderado. Ambos os grupos apresentaram alta incid?ncia de c?ncer de mama precocemente (83% dos indiv?duos). O grupo de portadores de muta??o nos genes de alto risco apresentaram maior ocorr?ncia de tumores de alto grau (83% vs 67%, P = 0,0090). No grupo de indiv?duos com muta??es em genes de risco moderado, os tumores apresentaram um fen?tipo mais agressivo com c?ncer bilateral (33% versus 11%, P = 0,0002), ocorr?ncia de met?stases (33% vs 5,6%, P <0,0001) e ?bito (33% vs 5,6%, P <0,0001). Ao todo, 1/3 de variantes foram identificadas em genes de risco moderado em pacientes com c?ncer mais agressivo. Estes resultados refor?am a import?ncia da aplica??o de an?lise multig?nica em indiv?duos em situa??o de risco para c?ncer de mama, especialmente em uma popula??o heterog?nea como brasileira. / Hereditary breast and ovarian cancer (HBOC) corresponds to 10-15% of all diagnosed cases of breast cancer in the world. The majority germline mutations are identified in BRCA1 and BRCA2 genes, however the application of multigene panels has increased the number of pathogenic variations detected in DNA repair genes. According to the current version of NCCN (National Comprehensive Cancer Network) Guideline, mutations in BRCA1, BRCA2, TP53 and PTEN confers high risk to develop breast cancer, and mutations in CDH1, CHEK2, PALB2, ATM and BRIP can increases over than 20% this risk. We analyzed 157 individuals with personal and/or familial breast cancer history. Genomic DNA was isolated from peripheral blood through saline-based extraction and samples were analyzed using next-generation sequencing (NGS). We identified 15 pathogenic variants and 4 VUS (Variants of Uncertain Significance) in 27 individuals (27/157; 17%), in which three are asymptomatic. Seven novel variants in 4 genes were identified: BRCA1_c.3409A>G; BRCA2_g.26826_30318del, BRCA2_c.5800C>T; BRCA2_c.5228G>A; BRCA2_c.5305delG; ATM_c.634delT and ATR_c.3043C>T. Sixty-eight percent (13/19; 68%) of variants was detected in BRCA1 and BRCA2 genes, while 32% (6/19) were identified in moderate risk genes ATM (2/19); ATR (1/19); CDH1 (1/19); MLH1 (1/19) and MSH6 (1/19). The individuals were separated in two groups for comparative analysis: high-risk genes and moderate risk genes. Among three asymptomatic individuals, two present variants in moderate risk genes ATM and MLH1. Among breast cancer individuals, eighteen patients (18/24; 75%) presented mutations in high-risk genes, while six (6/24; 25%) harbored mutations in moderate risk genes. Both groups had a high incidence of early-onset breast cancer, 83%. The group of individuals harboring variants in high-risk genes presented a greater occurrence of high-grade tumors (83% vs. 67%, P= 0.0090). In the group of individuals harboring mutation in moderate risk genes, tumors presented a more aggressive phenotype with bilateral cancer (33% vs. 11%, P= 0.0002), occurrence of metastasis (33% vs. 5.6%, P<0.0001) and incidence of deaths (33% vs. 5.6%, P<0.0001). Altogether, 1/3 of variants were identified in moderate risk genes in patients presenting a more aggressive phenotype. These results reinforce the importance of applying multigene analysis in individuals at-risk for breast cancer, especially in a heterogeneous population as Brazilian.

Summary: Background: An increased risk for development of hereditary breast cancer is associated with germline mutations in BRCA1/2 and the influence of NBN mutations is also supposed. The aim of this study is to specify the frequency of recurrent mutations in BRCA1/2 in unselected breast cancer patients and the frequency of most common pathogenic mutations in NBN in Czech republic, to assess current criteria for genetic testing and to consider the addition of NBN to the tested genes. Methods: Screening for recurrent mutations 5382insC and 300T>G in BRCA1 was performed by RFLP, screening for mutations in exon 11 of BRCA1 was performed by PTT, screening for mutations in a selected region of exon 11 of BRCA2 by DHPLC, and screening for mutations in exon 6 of NBN by HRMA. All the mutations were confirmed by direct sequencing. Results: In 679 unselected breast cancer patients 7 carriers of 5382insC, 3 of 300T>G, and 4 of other mutations in BRCA1 were identified. 2 locally prevalent mutations were found in BRCA2. In 730 controls only one 5382insC BRCA1 mutation was identified. Out of 5 NBN mutations found in 600 high-risk patients two were 657del5 and one R215W. A total of 8 NBN mutation carriers were identified among 703 breast cancer patients, 2 of them 657del5 carriers and three R215W carriers. In 915...