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1.
Hum Mutat ; 39(5): 593-620, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29446198

RESUMO

The prevalence and spectrum of germline mutations in BRCA1 and BRCA2 have been reported in single populations, with the majority of reports focused on White in Europe and North America. The Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) has assembled data on 18,435 families with BRCA1 mutations and 11,351 families with BRCA2 mutations ascertained from 69 centers in 49 countries on six continents. This study comprehensively describes the characteristics of the 1,650 unique BRCA1 and 1,731 unique BRCA2 deleterious (disease-associated) mutations identified in the CIMBA database. We observed substantial variation in mutation type and frequency by geographical region and race/ethnicity. In addition to known founder mutations, mutations of relatively high frequency were identified in specific racial/ethnic or geographic groups that may reflect founder mutations and which could be used in targeted (panel) first pass genotyping for specific populations. Knowledge of the population-specific mutational spectrum in BRCA1 and BRCA2 could inform efficient strategies for genetic testing and may justify a more broad-based oncogenetic testing in some populations.

2.
Nat Genet ; 49(12): 1767-1778, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29058716

RESUMO

Most common breast cancer susceptibility variants have been identified through genome-wide association studies (GWAS) of predominantly estrogen receptor (ER)-positive disease. We conducted a GWAS using 21,468 ER-negative cases and 100,594 controls combined with 18,908 BRCA1 mutation carriers (9,414 with breast cancer), all of European origin. We identified independent associations at P < 5 × 10-8 with ten variants at nine new loci. At P < 0.05, we replicated associations with 10 of 11 variants previously reported in ER-negative disease or BRCA1 mutation carrier GWAS and observed consistent associations with ER-negative disease for 105 susceptibility variants identified by other studies. These 125 variants explain approximately 16% of the familial risk of this breast cancer subtype. There was high genetic correlation (0.72) between risk of ER-negative breast cancer and breast cancer risk for BRCA1 mutation carriers. These findings may lead to improved risk prediction and inform further fine-mapping and functional work to better understand the biological basis of ER-negative breast cancer.


Assuntos
Proteína BRCA1/genética , Neoplasias da Mama/genética , Predisposição Genética para Doença/genética , Mutação , Polimorfismo de Nucleotídeo Único , Neoplasias da Mama/etnologia , Neoplasias da Mama/metabolismo , Grupo com Ancestrais do Continente Europeu/genética , Feminino , Predisposição Genética para Doença/etnologia , Estudo de Associação Genômica Ampla/métodos , Heterozigoto , Humanos , Receptores Estrogênicos/metabolismo , Fatores de Risco
3.
Sci Rep ; 6: 36874, 2016 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-27845421

RESUMO

NBS1, also known as NBN, plays an important role in maintaining genomic stability. Interestingly, rs2735383 G > C, located in a microRNA binding site in the 3'-untranslated region (UTR) of NBS1, was shown to be associated with increased susceptibility to lung and colorectal cancer. However, the relation between rs2735383 and susceptibility to breast cancer is not yet clear. Therefore, we genotyped rs2735383 in 1,170 familial non-BRCA1/2 breast cancer cases and 1,077 controls using PCR-based restriction fragment length polymorphism (RFLP-PCR) analysis, but found no association between rs2735383CC and breast cancer risk (OR = 1.214, 95% CI = 0.936-1.574, P = 0.144). Because we could not exclude a small effect size due to a limited sample size, we further analyzed imputed rs2735383 genotypes (r2 > 0.999) of 47,640 breast cancer cases and 46,656 controls from the Breast Cancer Association Consortium (BCAC). However, rs2735383CC was not associated with overall breast cancer risk in European (OR = 1.014, 95% CI = 0.969-1.060, P = 0.556) nor in Asian women (OR = 0.998, 95% CI = 0.905-1.100, P = 0.961). Subgroup analyses by age, age at menarche, age at menopause, menopausal status, number of pregnancies, breast feeding, family history and receptor status also did not reveal a significant association. This study therefore does not support the involvement of the genotype at NBS1 rs2735383 in breast cancer susceptibility.


Assuntos
Neoplasias da Mama/genética , Proteínas de Ciclo Celular/genética , MicroRNAs/metabolismo , Proteínas Nucleares/genética , Regiões 3' não Traduzidas , Alelos , Proteína BRCA1/genética , Proteína BRCA2/genética , Sítios de Ligação , Neoplasias da Mama/patologia , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Razão de Chances , Polimorfismo de Nucleotídeo Único , Fatores de Risco
4.
Nat Commun ; 7: 12675, 2016 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-27601076

RESUMO

A locus at 19p13 is associated with breast cancer (BC) and ovarian cancer (OC) risk. Here we analyse 438 SNPs in this region in 46,451 BC and 15,438 OC cases, 15,252 BRCA1 mutation carriers and 73,444 controls and identify 13 candidate causal SNPs associated with serous OC (P=9.2 × 10(-20)), ER-negative BC (P=1.1 × 10(-13)), BRCA1-associated BC (P=7.7 × 10(-16)) and triple negative BC (P-diff=2 × 10(-5)). Genotype-gene expression associations are identified for candidate target genes ANKLE1 (P=2 × 10(-3)) and ABHD8 (P<2 × 10(-3)). Chromosome conformation capture identifies interactions between four candidate SNPs and ABHD8, and luciferase assays indicate six risk alleles increased transactivation of the ADHD8 promoter. Targeted deletion of a region containing risk SNP rs56069439 in a putative enhancer induces ANKLE1 downregulation; and mRNA stability assays indicate functional effects for an ANKLE1 3'-UTR SNP. Altogether, these data suggest that multiple SNPs at 19p13 regulate ABHD8 and perhaps ANKLE1 expression, and indicate common mechanisms underlying breast and ovarian cancer risk.


Assuntos
Alelos , Neoplasias da Mama/genética , Cromossomos Humanos Par 19/genética , Predisposição Genética para Doença , Neoplasias Ovarianas/genética , Polimorfismo de Nucleotídeo Único , Grupo com Ancestrais do Continente Africano/genética , Grupo com Ancestrais do Continente Asiático/genética , Feminino , Estudo de Associação Genômica Ampla , Genótipo , Humanos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
5.
Nat Commun ; 7: 11375, 2016 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-27117709

RESUMO

Common variants in 94 loci have been associated with breast cancer including 15 loci with genome-wide significant associations (P<5 × 10(-8)) with oestrogen receptor (ER)-negative breast cancer and BRCA1-associated breast cancer risk. In this study, to identify new ER-negative susceptibility loci, we performed a meta-analysis of 11 genome-wide association studies (GWAS) consisting of 4,939 ER-negative cases and 14,352 controls, combined with 7,333 ER-negative cases and 42,468 controls and 15,252 BRCA1 mutation carriers genotyped on the iCOGS array. We identify four previously unidentified loci including two loci at 13q22 near KLF5, a 2p23.2 locus near WDR43 and a 2q33 locus near PPIL3 that display genome-wide significant associations with ER-negative breast cancer. In addition, 19 known breast cancer risk loci have genome-wide significant associations and 40 had moderate associations (P<0.05) with ER-negative disease. Using functional and eQTL studies we implicate TRMT61B and WDR43 at 2p23.2 and PPIL3 at 2q33 in ER-negative breast cancer aetiology. All ER-negative loci combined account for ∼11% of familial relative risk for ER-negative disease and may contribute to improved ER-negative and BRCA1 breast cancer risk prediction.


Assuntos
Neoplasias da Mama/genética , Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla/métodos , Receptores Estrogênicos/genética , Proteína BRCA1/genética , Cromossomos Humanos Par 2/genética , Ciclofilinas/genética , Feminino , Genótipo , Heterozigoto , Humanos , Mutação , Polimorfismo de Nucleotídeo Único , Fatores de Risco , tRNA Metiltransferases
6.
J Cancer Res Clin Oncol ; 142(3): 633-48, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26577826

RESUMO

BACKGROUND: Subjects referred to genetic counselling for cancer may have heightened perceptions of illness and death, even though they are healthy and this may cause anxiety and reluctance to follow through with consultation. We investigated such perceptions before and after counselling and genetic testing for cancer in a cohort of Italian women. We sought to understand the situation of the women referred by designing questionnaires administered to women at high risk of breast and/or ovarian cancer (those who had had a pathogenic mutation identified in a family member via diagnostic testing). We also assessed women after the diagnosis of breast cancers, but free of disease, to help determine risks in their families. METHODS: The first questionnaires were administered before initial counselling, and the second were completed within 20 days after the counselling. When a genetic test was proposed, the individual was asked to fill in a third questionnaire; the final questionnaire was administered after the person had received the results of the genetic test. RESULTS: We evaluated 204 subjects. Before counselling, 89 % of the subjects were worried about their risk of disease, 52 % felt "different" because of their personal and family history, and 39 % declared that their life choices were influenced by their fear of cancer. After counselling, 82 % of the subjects felt more relived about their pre-existing fears and stated that this process of being seen in a clinic with genetic expertise had clarified the meaning of disease risk for them, and for 50 %, this experience had positively influenced their life choices. Thirty percentage of the subjects had a positive test; all of them felt safer in being cared for by specifically trained staff. Fifty percentage had a less informative test (e.g. "wild-type" gene found); 84 % of them were not worried by the uncertainty, and overall, 96 % considered counselling to be very useful. CONCLUSION: Candidates for genetic counselling frequently had heightened their perception of being ill, which influenced their ability to make life decisions. Genetic counselling often improves this perception, especially in subjects who have negative tests and this knowledge facilitates their life plans. After testing, most women felt satisfied and safer because of being properly followed by professionally trained and sympathetic staff. In conclusion, knowledge of the real individual risk, the presence of a professional team, and the possibility of entering a programme of controlled screening enable patients rather than living in fear and uncertainty to be less anxious about their state of health and to live with the knowledge that they are doing everything possible to care for themselves, aided by a specialized team, and that, if necessary, they would be able to take part in investigational studies.


Assuntos
Neoplasias da Mama/psicologia , Aconselhamento Genético/psicologia , Neoplasias Ovarianas/psicologia , Percepção , Inquéritos e Questionários , Ansiedade/epidemiologia , Neoplasias da Mama/genética , Escolaridade , Feminino , Nível de Saúde , Humanos , Itália , Neoplasias Ovarianas/genética , Fatores de Risco
7.
Eur J Cancer ; 51(16): 2289-95, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26248686

RESUMO

Increasing evidence indicates that common genetic variants may contribute to the heritable risk of breast cancer (BC). In this study, we investigated whether single nucleotide polymorphisms (SNPs), within the 8q24.21 multi-cancer susceptibility region and within BC-associated loci widespread in the genome, may influence the risk of BC in men, and whether they may be associated with specific clinical-pathologic characteristics of male BC (MBC). In the frame of the ongoing Italian Multicenter Study on MBC, we performed a case-control study on 386 MBC cases, including 50 BRCA1/2 mutation carriers, and 1105 healthy male controls, including 197 unaffected BRCA1/2 mutation carriers. All 1491 subjects were genotyped by Sequenom iPLEX technology for a total of 29 susceptibility SNPs. By logistic regression models, we found a significant association with MBC risk for five SNPs: rs1562430 (p=0.002) and rs445114 (p=0.026) both within the 8q24.21 region; rs1011970/9p21.3 (p=0.011), rs614367/11q13.3 (p=0.016) and rs1314913/14q24.1 (p<0.0001). Differences in the distribution of rs614367/11q13.3 genotypes according to oestrogen receptor (ER) status (p=0.006), and of rs1011970/9p21.3 genotypes according to human epidermal growth factor receptor 2 (HER2) status (p=0.002) emerged. Association of rs1011970/9p21.3 risk genotype with HER2+MBC was confirmed by a multivariate analysis. rs1314913/14q24.1 was associated with increased MBC risk in analyses restricted to male BRCA1/2 mutation carriers (p=0.041). In conclusion, we provided the first evidence that the 8q24.21 region is associated with MBC risk. Furthermore, we showed that the SNPs rs1562430/8q24.21 and rs1314913/14q24.1 strongly influence BC risk in men and suggested that the SNP rs1314913/14q24.1 may act as a risk modifier locus in male BRCA1/2 mutation carriers.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias da Mama Masculina/genética , Cromossomos Humanos Par 11 , Cromossomos Humanos Par 14 , Cromossomos Humanos Par 8 , Cromossomos Humanos Par 9 , Polimorfismo de Nucleotídeo Único , Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias da Mama Masculina/patologia , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , Frequência do Gene , Predisposição Genética para Doença , Heterozigoto , Homozigoto , Humanos , Itália , Modelos Lineares , Modelos Logísticos , Masculino , Análise Multivariada , Mutação , Razão de Chances , Fenótipo , Valor Preditivo dos Testes , Fatores de Risco
8.
Genet Med ; 16(9): 688-94, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24556926

RESUMO

PURPOSE: Monoallelic germ-line deleterious mutations of PALB2 (partner and localizer of BRCA2) are associated with breast cancer risk and have been found in several populations, with carrier frequencies of ~1-2%. Initially, these mutations were considered to have moderate penetrance, but accumulating evidence now indicates that they are associated with much higher risk. METHODS: In this study, we sequenced the PALB2 coding regions unlinked to BRCA (breast cancer) genes in 575 probands from Italian breast cancer families recruited in Milan. RESULTS: We found 12 carriers (2.1%) of deleterious mutations, and none of the mutations was found in 784 controls collected in Milan. One of these mutations, the c.1027C>T (p.Gln343X), was found to be recurrent in the province of Bergamo in northern Italy, being detected in 6/113 (5.3%) familial breast cancer cases and 2/477 (0.4%) controls recruited in this area (Fisher's exact test: P < 0.01). CONCLUSIONS: Our data provide confirmatory findings that, in the Italian population also, deleterious mutations of PALB2 are relatively frequent predisposing factors for breast cancer and may be associated with high risk of the disease.


Assuntos
Grupo com Ancestrais do Continente Europeu/genética , Mutação , Proteínas Nucleares/genética , Proteínas Supressoras de Tumor/genética , Alelos , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Estudos de Casos e Controles , Análise Mutacional de DNA , Proteína do Grupo de Complementação N da Anemia de Fanconi , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Itália , Polimorfismo Genético
9.
PLoS One ; 9(2): e86924, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24516540

RESUMO

The identification of founder mutations in cancer predisposing genes is important to improve risk assessment in geographically defined populations, since it may provide specific targets resulting in cost-effective genetic testing. Here, we report the characterization of the BRCA1 c.190T>C (p.Cys64Arg) mutation, mapped to the RING-finger domain coding region, that we detected in 43 hereditary breast/ovarian cancer (HBOC) families, for the large part originating from the province of Bergamo (Northern Italy). Haplotype analysis was performed in 21 families, and led to the identification of a shared haplotype extending over three BRCA1-associated marker loci (0.4 cM). Using the DMLE+2.2 software program and regional population demographic data, we were able to estimate the age of the mutation to vary between 3,100 and 3,350 years old. Functional characterization of the mutation was carried out at both transcript and protein level. Reverse transcriptase-PCR analysis on lymphoblastoid cells revealed expression of full length mRNA from the mutant allele. A green fluorescent protein (GFP)-fragment reassembly assay showed that the p.Cys64Arg substitution prevents the binding of the BRCA1 protein to the interacting protein BARD1, in a similar way as proven deleterious mutations in the RING-domain. Overall, 55 of 83 (66%) female mutation carriers had a diagnosis of breast and/or ovarian cancer. Our observations indicate that the BRCA1 c.190T>C is a pathogenic founder mutation present in the Italian population. Further analyses will evaluate whether screening for this mutation can be suggested as an effective strategy for the rapid identification of at-risk individuals in the Bergamo area.


Assuntos
Proteína BRCA1/química , Proteína BRCA1/genética , Efeito Fundador , Predisposição Genética para Doença , Mutação/genética , Adulto , Fatores Etários , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Segregação de Cromossomos/genética , Éxons/genética , Família , Feminino , Regulação Neoplásica da Expressão Gênica , Geografia , Proteínas de Fluorescência Verde/metabolismo , Haplótipos/genética , Humanos , Itália , Pessoa de Meia-Idade , Taxa de Mutação , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Ligação Proteica , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Domínios RING Finger , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina-Proteína Ligases/metabolismo
10.
Genes Chromosomes Cancer ; 53(5): 432-45, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24493355

RESUMO

Germline inactivation of the E-cadherin gene (CDH1) is associated with hereditary diffuse gastric cancer (HDGC), a rare autosomal dominant syndrome predisposing to both diffuse gastric cancer (DGC) and lobular breast cancer (LBC). We searched for CDH1 germline defects in 32 HDGC Italian probands selected according to international consensus criteria and in 5 selected relatives. We used a series of molecular methods, including: DNA sequencing, multiplex ligation-dependent probe amplification, single-nucleotide primer extension, bisulfite sequencing, reverse-transcription PCR, and bioinformatics tools. We identified pathogenic mutations in 6 out of 32 probands (19%): one truncating and two missense mutations, one large deletion, one allelic expression imbalance and one splicing defect. Three out of six CDH1 constitutive alterations were novel. Our data support the need for a multimethod approach for CDH1 genetic testing, demonstrating that both DNA and RNA analyses are required to increase the detection rate of pathogenic mutations, thus reducing the number of patients without a clear molecular diagnosis. On the whole, our results indicate that not only DGC patients, but also subjects with personal or family history of LBC might benefit from CDH1 genetic testing. Moreover, our findings support the notion that prophylactic gastrectomy should be offered to asymptomatic CDH1 mutation carriers; indeed, while endoscopic analysis with histological examination of random gastric biopsies can miss cancer foci, gastrectomy performed in these subjects always revealed foci of cancer cells.


Assuntos
Caderinas/genética , Heterogeneidade Genética , Neoplasias Gástricas/genética , Adulto , Desequilíbrio Alélico , Antígenos CD , Neoplasias da Mama/genética , Carcinoma Lobular/genética , Feminino , Deleção de Genes , Mutação em Linhagem Germinativa , Humanos , Itália , Pessoa de Meia-Idade , Linhagem , Regiões Promotoras Genéticas
11.
PLoS One ; 8(2): e57173, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23451180

RESUMO

Several unclassified variants (UVs) have been identified in splicing regions of disease-associated genes and their characterization as pathogenic mutations or benign polymorphisms is crucial for the understanding of their role in disease development. In this study, 24 UVs located at BRCA1 and BRCA2 splice sites were characterized by transcripts analysis. These results were used to evaluate the ability of nine bioinformatics programs in predicting genetic variants causing aberrant splicing (spliceogenic variants) and the nature of aberrant transcripts. Eleven variants in BRCA1 and 8 in BRCA2, including 8 not previously characterized at transcript level, were ascertained to affect mRNA splicing. Of these, 16 led to the synthesis of aberrant transcripts containing premature termination codons (PTCs), 2 to the up-regulation of naturally occurring alternative transcripts containing PTCs, and one to an in-frame deletion within the region coding for the DNA binding domain of BRCA2, causing the loss of the ability to bind the partner protein DSS1 and ssDNA. For each computational program, we evaluated the rate of non-informative analyses, i.e. those that did not recognize the natural splice sites in the wild-type sequence, and the rate of false positive predictions, i.e., variants incorrectly classified as spliceogenic, as a measure of their specificity, under conditions setting sensitivity of predictions to 100%. The programs that performed better were Human Splicing Finder and Automated Splice Site Analyses, both exhibiting 100% informativeness and specificity. For 10 mutations the activation of cryptic splice sites was observed, but we were unable to derive simple criteria to select, among the different cryptic sites predicted by the bioinformatics analyses, those actually used. Consistent with previous reports, our study provides evidences that in silico tools can be used for selecting splice site variants for in vitro analyses. However, the latter remain mandatory for the characterization of the nature of aberrant transcripts.


Assuntos
Genes BRCA1 , Genes BRCA2 , Mutação , Processamento de RNA , Linhagem Celular Transformada , Humanos , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
12.
Exp Dermatol ; 21(9): 718-20, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22804906

RESUMO

Host, environmental and genetic factors differently modulate cutaneous melanoma (CM) risk across populations. Currently, the main genetic risk determinants are germline mutations in the major known high-risk susceptibility genes, CDKN2A and CDK4, and variants of the low-risk gene MC1R, which is key in the pigmentation process. This case-control study aimed at investigating the influence of the main host and environmental risk factors and of MC1R variation on CM risk in 390 CDKN2A-negative and 49 CDKN2A-positive Italian individuals. Multivariate analysis showed that MC1R variation, number of nevi and childhood sunburns doubled CM risk in CDKN2A-negative individuals. In CDKN2A-positive individuals, family history of CM and presence of atypical nevi, rather than MC1R status, modified risk (20.75- and 2.83-fold, respectively). Occupational sun exposure increased CM risk (three to sixfold) in both CDKN2A-negative and CDKN2A-positive individuals, reflecting the occupational habits of the Ligurian population and the geographical position of Liguria.


Assuntos
Genes p16 , Melanoma/genética , Exposição Ocupacional/efeitos adversos , Receptor Tipo 1 de Melanocortina/genética , Neoplasias Cutâneas/genética , Luz Solar/efeitos adversos , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Intervalos de Confiança , Feminino , Humanos , Itália , Masculino , Melanoma/etiologia , Pessoa de Meia-Idade , Análise Multivariada , Mutação , Nevo/patologia , Razão de Chances , Fatores de Risco , Neoplasias Cutâneas/etiologia , Queimadura Solar/complicações , Adulto Jovem
13.
Hum Mutat ; 33(12): 1665-75, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22753153

RESUMO

Mutations in the BRCA1 gene confer a substantial increase in breast cancer risk, yet routine clinical genetic screening is limited to the coding regions and intron-exon boundaries, precluding the identification of mutations in noncoding and untranslated regions (UTR). As 3'UTR mutations can influence cancer susceptibility by altering protein and microRNA (miRNA) binding regions, we screened the BRCA1 3'UTR for mutations in a large series of BRCA-mutation negative, population and clinic-based breast cancer cases, and controls. Fifteen novel BRCA1 3'UTR variants were identified, the majority of which were unique to either cases or controls. Using luciferase reporter assays, three variants found in cases, c.* 528G>C, c.* 718A>G, and c.* 1271T>C and four found in controls, c.* 309T>C, c.* 379G>A, c.* 823C>T, and c.* 264C>T, reduced 3'UTR activity (P < 0.02), whereas two variants found in cases, c.* 291C>T and c.* 1139G>T, increased 3'UTR activity (P < 0.01). Three case variants, c.* 718A>G, c.* 800T>C, and c.* 1340_1342delTGT, were predicted to create new miRNA binding sites and c.* 1340_1342delTGT caused a reduction (25%, P = 0.0007) in 3'UTR reporter activity when coexpressed with the predicted targeting miRNA, miR-103. This is the most comprehensive identification and analysis of BRCA1 3'UTR variants published to date.


Assuntos
Regiões 3' não Traduzidas , Proteína BRCA1/genética , Neoplasias da Mama/genética , Regulação Neoplásica da Expressão Gênica , Mutação em Linhagem Germinativa , MicroRNAs/genética , Adulto , Pareamento de Bases , Sequência de Bases , Sítios de Ligação , Estudos de Casos e Controles , Linhagem Celular Tumoral , Sequência Conservada , Análise Mutacional de DNA , Proteínas ELAV , Feminino , Frequência do Gene , Estudos de Associação Genética , Humanos , Conformação de Ácido Nucleico , Polimorfismo de Nucleotídeo Único , Ligação Proteica , Interferência de RNA , RNA Mensageiro/genética
14.
Breast Cancer Res Treat ; 134(1): 411-8, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22527108

RESUMO

Recently, the number of studies on male breast cancer (MBC) has been increasing. However, as MBC is a rare disease there are difficulties to undertake studies to identify specific MBC subgroups. At present, it is still largely unknown whether BRCA-related breast cancer (BC) in men may display specific characteristics as it is for BRCA-related BC in women. To investigate the clinical-pathologic features of MBC in association with BRCA mutations we established a collaborative Italian Multicenter Study on MBC with the aim to recruit a large series of MBCs. A total of 382 MBCs, including 50 BRCA carriers, were collected from ten Italian Investigation Centres covering the whole country. In MBC patients, BRCA2 mutations were associated with family history of breast/ovarian cancer (p<0.0001), personal history of other cancers (p=0.044) and contralateral BC (p=0.001). BRCA2-associated MBCs presented with high tumor grade (p=0.001), PR-(p=0.026) and HER2+ (p=0.001) status. In a multivariate logistic model BRCA2 mutations showed positive association with personal history of other cancers (OR 11.42, 95% CI 1.79-73.08) and high tumor grade (OR 4.93, 95% CI 1.02-23.88) and inverse association with PR+ status (OR 0.19, 95% CI 0.04-0.92). Based on immunohistochemical (IHC) profile, four molecular subtypes of MBC were identified. Luminal A was the most common subtype (67.7%), luminal B was observed in 26.5% of the cases and HER2 positive and triple negative were represented by 2.1% and 3.7% of tumors, respectively. Intriguingly, we found that both luminal B and HER2 positive subtypes were associated with high tumor grade (p=0.003 and 0.006, respectively) and with BRCA2 mutations (p=0.016 and 0.001, respectively). In conclusion, our findings indicate that BRCA2-related MBCs represent a subgroup of tumors with a peculiar phenotype characterized by aggressive behavior. The identification of a BRCA2-associated phenotype might define a subset of MBC patients eligible for personalized clinical management.


Assuntos
Neoplasias da Mama Masculina/genética , Carcinoma Ductal de Mama/genética , Genes BRCA1 , Genes BRCA2 , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama Masculina/patologia , Carcinoma Ductal de Mama/patologia , Análise Mutacional de DNA , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Adulto Jovem
15.
PLoS One ; 7(2): e31038, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22383991

RESUMO

Breast cancer can be caused by germline mutations in several genes that are responsible for different hereditary cancer syndromes. Some of the genes causing the Fanconi anemia (FA) syndrome, such as BRCA2, BRIP1, PALB2, and RAD51C, are associated with high or moderate risk of developing breast cancer. Very recently, SLX4 has been established as a new FA gene raising the question of its implication in breast cancer risk. This study aimed at answering this question sequencing the entire coding region of SLX4 in 526 familial breast cancer cases from Italy. We found 81 different germline variants and none of these were clearly pathogenic. The statistical power of our sample size allows concluding that in Italy the frequency of carriers of truncating mutations of SLX4 may not exceed 0.6%. Our results indicate that testing for SLX4 germline mutations is unlikely to be relevant for the identification of individuals at risk of breast cancer, at least in the Italian population.


Assuntos
Neoplasias da Mama/genética , Recombinases/genética , Análise de Sequência de DNA , Análise Mutacional de DNA , Saúde da Família , Feminino , Deleção de Genes , Predisposição Genética para Doença , Humanos , Itália , Modelos Estatísticos , Mutação , Filogenia
17.
Breast Cancer Res Treat ; 134(1): 131-7, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22228432

RESUMO

Triple-negative breast cancers are characterized by the triple-negative (ER/PgR/Her2 negative) phenotype, are frequently associated with BRCA gene mutation, and are not candidate to currently available endocrine and HER2-targeted treatments. MGMT is involved in direct DNA repair exerted by cleavage of mutagenic alkyl adducts within DNA, and its epigenetic silencing confers susceptibility to DNA-damaging alkylating agents in glioblastomas and melanomas. MGMT methylation status has not been extensively investigated in breast cancer patients. The goal of our study was to evaluate the MGMT methylation status in TNBC patients, for most of which BRCA1 and BRCA2 mutational status was known. We evaluated MGMT methylation status by methylation-specific PCR (MSP) in formalin-fixed and paraffin-embedded tumor specimens from 92 TNBC patients. By using the GelDoc system (Biorad) software, the cases were further classified as follows: 0 (absence of methylated signal), 1 (prevalence of unmethylated signal, U/M ratio>1), 2 (prevalence of methylated signal, U/M ratio<1), and 3 (absence of unmethylated signal). MSP products were obtained in 89 (96.7%) of the cases. Overall, 15 (16.9%) cases were classified as 0, 33 (37.1%) cases as 1, 39 (43.8%) cases as 2, and 2 (2.2%) cases as 3. The 48 cases classified as 0 and 1 were considered as MGMT unmethylated, and the 41 cases classified as 2 and 3 as MGMT methylated. The prevalence of MGMT methylation in patients with BRCA1 mutated, wild-type, and unknown was 30.2% (13/43), 63.6% (14/22), and 58.3% (14/24), respectively. MGMT methylation was unrelated to the main clinical pathological characteristics, with the exception of a weak association with advanced age. In conclusion, our data suggest that in TNBC with wild-type BRCA1, the direct DNA repair system may be frequently (63.6%) silenced by MGMT methylation. The evaluation of the MGMT status could offer a new adjunct in predicting tumor response to alkylating drugs in TNBC patients.


Assuntos
Neoplasias da Mama/genética , Metilação de DNA , Metilases de Modificação do DNA/genética , Enzimas Reparadoras do DNA/genética , Regulação Neoplásica da Expressão Gênica , Regiões Promotoras Genéticas , Proteínas Supressoras de Tumor/genética , Adulto , Idoso , Proteína BRCA1/genética , Neoplasias da Mama/metabolismo , Análise Mutacional de DNA , Feminino , Humanos , Pessoa de Meia-Idade , Receptor ErbB-2/metabolismo , Receptores Estrogênicos/metabolismo , Receptores de Progesterona/metabolismo , Estudos Retrospectivos
18.
Cancer Epidemiol Biomarkers Prev ; 21(1): 134-47, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22144499

RESUMO

BACKGROUND: Previously, small studies have found that BRCA1 and BRCA2 breast tumors differ in their pathology. Analysis of larger datasets of mutation carriers should allow further tumor characterization. METHODS: We used data from 4,325 BRCA1 and 2,568 BRCA2 mutation carriers to analyze the pathology of invasive breast, ovarian, and contralateral breast cancers. RESULTS: There was strong evidence that the proportion of estrogen receptor (ER)-negative breast tumors decreased with age at diagnosis among BRCA1 (P-trend = 1.2 × 10(-5)), but increased with age at diagnosis among BRCA2, carriers (P-trend = 6.8 × 10(-6)). The proportion of triple-negative tumors decreased with age at diagnosis in BRCA1 carriers but increased with age at diagnosis of BRCA2 carriers. In both BRCA1 and BRCA2 carriers, ER-negative tumors were of higher histologic grade than ER-positive tumors (grade 3 vs. grade 1; P = 1.2 × 10(-13) for BRCA1 and P = 0.001 for BRCA2). ER and progesterone receptor (PR) expression were independently associated with mutation carrier status [ER-positive odds ratio (OR) for BRCA2 = 9.4, 95% CI: 7.0-12.6 and PR-positive OR = 1.7, 95% CI: 1.3-2.3, under joint analysis]. Lobular tumors were more likely to be BRCA2-related (OR for BRCA2 = 3.3, 95% CI: 2.4-4.4; P = 4.4 × 10(-14)), and medullary tumors BRCA1-related (OR for BRCA2 = 0.25, 95% CI: 0.18-0.35; P = 2.3 × 10(-15)). ER-status of the first breast cancer was predictive of ER-status of asynchronous contralateral breast cancer (P = 0.0004 for BRCA1; P = 0.002 for BRCA2). There were no significant differences in ovarian cancer morphology between BRCA1 and BRCA2 carriers (serous: 67%; mucinous: 1%; endometrioid: 12%; clear-cell: 2%). CONCLUSIONS/IMPACT: Pathologic characteristics of BRCA1 and BRCA2 tumors may be useful for improving risk-prediction algorithms and informing clinical strategies for screening and prophylaxis.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Genes BRCA1 , Genes BRCA2 , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Adulto , Idoso , Feminino , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Humanos , Pessoa de Meia-Idade , Gradação de Tumores
20.
Hum Mol Genet ; 20(16): 3304-21, 2011 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-21593217

RESUMO

Two single nucleotide polymorphisms (SNPs) at 6q25.1, near the ESR1 gene, have been implicated in the susceptibility to breast cancer for Asian (rs2046210) and European women (rs9397435). A genome-wide association study in Europeans identified two further breast cancer susceptibility variants: rs11249433 at 1p11.2 and rs999737 in RAD51L1 at 14q24.1. Although previously identified breast cancer susceptibility variants have been shown to be associated with breast cancer risk for BRCA1 and BRCA2 mutation carriers, the involvement of these SNPs to breast cancer susceptibility in mutation carriers is currently unknown. To address this, we genotyped these SNPs in BRCA1 and BRCA2 mutation carriers from 42 studies from the Consortium of Investigators of Modifiers of BRCA1/2. In the analysis of 14 123 BRCA1 and 8053 BRCA2 mutation carriers of European ancestry, the 6q25.1 SNPs (r(2) = 0.14) were independently associated with the risk of breast cancer for BRCA1 mutation carriers [hazard ratio (HR) = 1.17, 95% confidence interval (CI): 1.11-1.23, P-trend = 4.5 × 10(-9) for rs2046210; HR = 1.28, 95% CI: 1.18-1.40, P-trend = 1.3 × 10(-8) for rs9397435], but only rs9397435 was associated with the risk for BRCA2 carriers (HR = 1.14, 95% CI: 1.01-1.28, P-trend = 0.031). SNP rs11249433 (1p11.2) was associated with the risk of breast cancer for BRCA2 mutation carriers (HR = 1.09, 95% CI: 1.02-1.17, P-trend = 0.015), but was not associated with breast cancer risk for BRCA1 mutation carriers (HR = 0.97, 95% CI: 0.92-1.02, P-trend = 0.20). SNP rs999737 (RAD51L1) was not associated with breast cancer risk for either BRCA1 or BRCA2 mutation carriers (P-trend = 0.27 and 0.30, respectively). The identification of SNPs at 6q25.1 associated with breast cancer risk for BRCA1 mutation carriers will lead to a better understanding of the biology of tumour development in these women.


Assuntos
Alelos , Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias da Mama/genética , Cromossomos Humanos/genética , Predisposição Genética para Doença , Mutação/genética , Adulto , Idoso , Cromossomos Humanos Par 1/genética , Cromossomos Humanos Par 6/genética , Feminino , Heterozigoto , Humanos , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/genética , Fatores de Risco
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