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1.
Endocr Connect ; 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31336362

RESUMO

Breast cancer in men is a rare and still poorly characterized disease. Inherited mutations in BRCA1, BRCA2 and PALB2 genes, as well as common polymorphisms, play a role in male breast cancer genetic predisposition. Male breast cancer is considered a hormone-dependent tumor specifically related to hyperestrogenism. Polymorphisms in genes involved in estrogen biosynthesis and metabolism pathways, such as CYP17A1 and CYP1B1, have been associated with breast cancer risk. Here, we aimed to investigate the role of CYP17A1 and CYP1B1 polymorphisms in male breast cancer risk. A series of 597 male breast cancer cases and 1022 male controls, recruited within the Italian Multicenter Study on male breast cancer, was genotyped for CYP17A1 rs743572, CYP1B1 rs1056836 and rs1800440 polymorphisms by allelic discrimination real-time PCR with TaqMan probes. Associations with male breast cancer risk were estimated using logistic regression. No statistically significant associations between male breast cancer risk and the three analyzed polymorphisms emerged. Similar results were obtained also when BRCA1/2 mutational status was considered. No significant differences in the distribution of the genotypes according to estrogen receptor status emerged. In conclusion, our study, based on a large series of male breast cancer cases, is likely to exclude a relevant role of CYP17A1 and CYP1B1 polymorphisms in male breast cancer predisposition. Overall, these results add new data to the increasing evidence that polymorphisms in these genes may not be associated with breast cancer risk.

2.
Mol Genet Genomic Med ; 7(5): e587, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30916491

RESUMO

BACKGROUND: Inherited epimutations of Mismatch Repair (MMR) genes are responsible for Lynch Syndrome (LS) in a small, but well defined, subset of patients. Methylation of the MSH2 promoter consequent to the deletion of the upstream EPCAM gene is found in about 1%-3% of the LS patients and represents a classical secondary, constitutional and tissue-specific epimutation. Several different EPCAM deletions have been reported worldwide, for the most part representing private variants caused by an Alu-mediated recombination. METHODS: 712 patients with suspected LS were tested for MMR mutation in our Institute. EPCAM deletions were detected by multiplex ligation-dependent probe amplification (MLPA) and then defined by Long-Range polymerase chain reaction (PCR)/Sanger sequencing. A comprehensive molecular characterization of colorectal cancer (CRC) tissues was carried out by immunohistochemistry of MMR proteins, Microsatellite Instability (MSI) assay, methylation specific MLPA and transcript analyses. In addition, somatic deletions and/or variants were investigated by MLPA and next generation sequencing (NGS). RESULTS: An EPCAM deletion was found in five unrelated probands in Italy: variants c.556-490_*8438del and c.858+1193_*5826del are novel; c.859-1430_*2033del and c.859-670_*530del were previously reported. All probands were affected by CRC at young age; tumors showed MSI and abnormal MSH2/MSH6 proteins expression. MSH2 promoter methylation, as well as aberrant in-frame or out-of-frame EPCAM/MSH2 fusion transcripts, were detected in CRCs and normal mucosae. CONCLUSION: An EPCAM deletion was the causative variant in about 2% of our institutional series of 224 LS patients, consistent with previously estimated frequencies. Early age and multiple CRCs was the main clinical feature of this subset of patients.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/genética , Molécula de Adesão da Célula Epitelial/genética , Deleção de Genes , Frequência do Gene , Adulto , Metilação de DNA , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteína 2 Homóloga a MutS/genética , Proteína 2 Homóloga a MutS/metabolismo , Fenótipo
3.
Int J Cancer ; 145(2): 390-400, 2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-30613976

RESUMO

Breast cancer (BC) in men is rare and genetic predisposition is likely to play a relevant role in its etiology. Inherited mutations in BRCA1/2 account for about 13% of all cases and additional genes that may contribute to the missing heritability need to be investigated. In our study, a well-characterized series of 523 male BC (MBC) patients from the Italian multicenter study on MBC, enriched for non-BRCA1/2 MBC cases, was screened by a multigene custom panel of 50 cancer-associated genes. The main clinical-pathologic characteristics of MBC in pathogenic variant carriers and non-carriers were also compared. BRCA1/2 pathogenic variants were detected in twenty patients, thus, a total of 503 non-BRCA1/2 MBC patients were examined in our study. Twenty-seven of the non-BRCA1/2 MBC patients were carriers of germline pathogenic variants in other genes, including two APC p.Ile1307Lys variant carriers and one MUTYH biallelic variant carrier. PALB2 was the most frequently altered gene (1.2%) and PALB2 pathogenic variants were significantly associated with high risk of MBC. Non-BRCA1/2 pathogenic variant carriers were more likely to have personal (p = 0.0005) and family (p = 0.007) history of cancer. Results of our study support a central role of PALB2 in MBC susceptibility and show a low impact of CHEK2 on MBC predisposition in the Italian population. Overall, our data indicate that a multigene testing approach may benefit from appropriately selected patients with implications for clinical management and counseling of MBC patients and their family members.


Assuntos
Neoplasias da Mama Masculina/genética , Quinase do Ponto de Checagem 2/genética , Proteína do Grupo de Complementação N da Anemia de Fanconi/genética , Mutação , Análise de Sequência de DNA/métodos , Proteína da Polipose Adenomatosa do Colo/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , DNA Glicosilases/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Adulto Jovem
4.
Fam Cancer ; 2018 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-30196345

RESUMO

Relatively little is known on the genotype-phenotype correlations between SMAD4 gene mutations, juvenile polyposis of the intestine and Hereditary Hemorrhagic Teleangectasia. We describe a family in which the proband (a 46-year old woman) had massive polyposis of the stomach-leading to surgery-with high-grade dysplasia at histology. Molecular analysis was carried out using Next Generation sequencing techniques with Miseq Illumina Platforms and a minimal coverage of 40 reads. In the proband, the analysis showed the presence of a truncating mutation in the SMAD4 gene (c.1213dupC, a variant previously associated with juvenile polyposis and Hereditary Hemorrhagic Teleangectasia). The same mutation was detected in two other members of the family (father and brother of the proband), who showed massive polypoid involvement of the stomach at gastroscopy. By taking the family history, subtle evidence of Hereditary Teleangectasia was found (nasal bleeding and arterovenous malformations) in the three gene carriers. Colonoscopy showed polyp occurrence in all three affected members with SMAD4 mutation, with prevalence of adenomatous lesions in one (father), of hamartomas in the brother, and of a mix of histological types in the proband. The main features of the family can be summarized as follows: (A) In hereditary juvenile polyposis, lesions of different histology can be detected at colonoscopy; (B) In the gene carriers of SMAD4 mutations, lesions of the stomach require careful surveillance and, when necessary, surgical interventions; (C) Signs and symptoms of Hereditary Hemorrhagic Teleangectasia should be suspected (and searched) in individuals with SMAD4 constitutional mutations.

5.
Int J Mol Sci ; 19(6)2018 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-29882764

RESUMO

Lynch syndrome (LS) and familial adenomatous polyposis (FAP) are autosomal dominant hereditary diseases caused by germline mutations leading to the development of colorectal cancer. Moreover, these mutations result in the development of a spectrum of different tumors, including gastric cancers (GCs). Since the clinical characteristics of GCs associated with LS and FAP are not well known, we investigated clinical and molecular features of GCs occurring in patients with LS and FAP attending our Institution. The Hereditary Tumor Registry was established in 1994 at the Department of Oncologic Gastroenterology, CRO Aviano National Cancer Institute, Italy. It includes 139 patients with LS and 86 patients with FAP. Patients were recruited locally for prospective surveillance. Out of 139 LS patients, 4 developed GC—3 in the presence of helicobacter pylori infection and 1 on the background of autoimmune diseases. All GCs displayed a high microsatellite instability (MSI-H) and loss of related mismatch repair (MMR) protein. One of the FAP patients developed a flat adenoma, displaying low-grade dysplasia at the gastric body, and another poorly differentiated adenocarcinoma with signet ring cells like Krukenberg without HP infection. LS carriers displayed a risk of GC. The recognition of HP infection and autoimmune diseases would indicate those at higher risk for an endoscopic surveillance. Regarding FAP, the data suggested the need of suitable endoscopic surveillance in long survivals with diffuse fundic gland polyps.


Assuntos
Polipose Adenomatosa do Colo/patologia , Neoplasias Colorretais Hereditárias sem Polipose/patologia , Neoplasias Gástricas/patologia , Polipose Adenomatosa do Colo/genética , Adulto , Idoso , Antígenos CD , Caderinas/genética , Neoplasias Colorretais Hereditárias sem Polipose/genética , Reparo de Erro de Pareamento de DNA , Feminino , Mutação em Linhagem Germinativa , Humanos , Masculino , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Estudos Prospectivos , Neoplasias Gástricas/genética
6.
Breast ; 38: 92-97, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29287190

RESUMO

INTRODUCTION: Breast cancer (BC) in men is a rare disease, whose etiology appears to be associated with genetic factors. Inherited mutations in BRCA1/2 genes account for about 10-15% of all cases. FANCM, functionally linked to BRCA1/2, has been suggested as a novel BC susceptibility gene. Our aim was to test if FANCM germline mutations could further explain male BC (MBC) susceptibility. METHODS: We screened the entire coding region of FANCM in 286 MBCs by a multi-gene panel analysis, and compared these data with available whole exome sequencing data from 415 men used as population controls. Moreover, we genotyped the two most frequent FANCM mutations (c.5101C>T and c.5791C>T) in 506 MBCs and 854 healthy male controls. RESULTS: Two FANCM truncating mutations, the c.1432C>T (p.Arg478Ter) and c.1972C>T (p.Arg658Ter), were identified in two MBC cases (0.7%). When specifically considering cases at increased genetic risk for BC, FANCM mutation frequency raises up to 1%. One mutation, the c.2201_2202delCT (p.Ser734Terfs), was found among controls (0.24%). Mutation frequency in cases was higher than in controls, however this difference was not statistically significant. FANCM c.5101C>T was not present in any of the cases and controls analyzed, whereas FANCM c.5791C>T was found in two controls (0.23%). CONCLUSION: Rare FANCM truncating mutations, other than c.5101C>T and c.5791C>T, may have a role in MBC susceptibility. The inclusion of FANCM in gene panels for research purpose would allow for the identification of a higher number of mutation carriers, thus helping estimate BC risk associated with FANCM mutations.


Assuntos
Neoplasias da Mama Masculina/genética , DNA Helicases/genética , Predisposição Genética para Doença/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Estudos de Casos e Controles , Genótipo , Mutação em Linhagem Germinativa , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Sequenciamento Completo do Genoma , Adulto Jovem
7.
EBioMedicine ; 20: 39-49, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28551381

RESUMO

8-Oxoguanine, a common mutagenic DNA lesion, generates G:C>T:A transversions via mispairing with adenine during DNA replication. When operating normally, the MUTYH DNA glycosylase prevents 8-oxoguanine-related mutagenesis by excising the incorporated adenine. Biallelic MUTYH mutations impair this enzymatic function and are associated with colorectal cancer (CRC) in MUTYH-Associated Polyposis (MAP) syndrome. Here, we perform whole-exome sequencing that reveals a modest mutator phenotype in MAP CRCs compared to sporadic CRC stem cell lines or bulk tumours. The excess G:C>T:A transversion mutations in MAP CRCs exhibits a novel mutational signature, termed Signature 36, with a strong sequence dependence. The MUTYH mutational signature reflecting persistent 8-oxoG:A mismatches occurs frequently in the APC, KRAS, PIK3CA, FAT4, TP53, FAT1, AMER1, KDM6A, SMAD4 and SMAD2 genes that are associated with CRC. The occurrence of Signature 36 in other types of human cancer indicates that DNA 8-oxoguanine-related mutations might contribute to the development of cancer in other organs.


Assuntos
Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Dano ao DNA , DNA Glicosilases/genética , Guanina/análogos & derivados , Alelos , Neoplasias Colorretais/patologia , DNA Glicosilases/metabolismo , Análise Mutacional de DNA , Reparo do DNA , Frequência do Gene , Genes Supressores de Tumor , Estudos de Associação Genética , Predisposição Genética para Doença , Guanina/metabolismo , Humanos , Instabilidade de Microssatélites , Mutação , Taxa de Mutação , Oncogenes , Sequenciamento Completo do Exoma
8.
Int J Gynecol Cancer ; 27(7): 1543-1549, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28471861

RESUMO

OBJECTIVE: Recent data from the literature indicate gynecological cancers (GCs) as sentinel cancers for a diagnosis of Lynch syndrome (LS). Clinical approaches to identifying LS have low sensitivity, whereas somatic tests on GCs may be a more sensitive and cost-effective strategy. METHODS: A series of 78 GCs belonging to 74 patients sent to the Genetic Counselling Service were investigated using microsatellite instability, immunohistochemical expression of mismatch repair (MMR) genes, and MLH1 promoter methylation. RESULTS: The presence of microsatellite instability was observed in 67.5% of GCs, and the absence of immunohistochemical expression of at least 1 of the 4 MMR proteins was observed in 71.4% of GCs, showing 96.1% concordance between the methods. Methylation analysis using methylation specific multiplex ligation-dependent probe amplification performed on 35 samples revealed MLH1 promoter hypermethylation in 18 cases (54%). Molecular analysis identified 36 LS carriers of MMR variants (27 pathogenetic and 9 variants of uncertain significance), and, interestingly, 3 LS patients had MLH1 methylated GC.With regard to histological features, LS-related GCs included endocervical cancers and also histological types different from the endometrioid cancers. The presence of peritumoral lymphocytes in GCs was statistically associated with LS tumors. CONCLUSIONS: Somatic analysis is a useful strategy to distinguish sporadic from LS GC. Our data allow the identification of a subset of LS patients otherwise unrecognized on the basis of clinical or family history alone. In addition, our results indicate that some clinicopathological features including age of GC diagnosis; presence of peritumoral lymphocytes; isthmic, endocervical sites, and body mass index value could be useful criteria to select patients for genetic counseling.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Neoplasias dos Genitais Femininos/diagnóstico , Adulto , Idoso , Neoplasias Colorretais Hereditárias sem Polipose/genética , Neoplasias Colorretais Hereditárias sem Polipose/metabolismo , Metilação de DNA , Enzimas Reparadoras do DNA/biossíntese , Enzimas Reparadoras do DNA/genética , Feminino , Neoplasias dos Genitais Femininos/genética , Neoplasias dos Genitais Femininos/metabolismo , Humanos , Imuno-Histoquímica , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL/biossíntese , Proteína 1 Homóloga a MutL/genética , Regiões Promotoras Genéticas
9.
J Clin Oncol ; 35(20): 2240-2250, 2017 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-28448241

RESUMO

Purpose BRCA1/2 mutations increase the risk of breast and prostate cancer in men. Common genetic variants modify cancer risks for female carriers of BRCA1/2 mutations. We investigated-for the first time to our knowledge-associations of common genetic variants with breast and prostate cancer risks for male carriers of BRCA1/ 2 mutations and implications for cancer risk prediction. Materials and Methods We genotyped 1,802 male carriers of BRCA1/2 mutations from the Consortium of Investigators of Modifiers of BRCA1/2 by using the custom Illumina OncoArray. We investigated the combined effects of established breast and prostate cancer susceptibility variants on cancer risks for male carriers of BRCA1/2 mutations by constructing weighted polygenic risk scores (PRSs) using published effect estimates as weights. Results In male carriers of BRCA1/2 mutations, PRS that was based on 88 female breast cancer susceptibility variants was associated with breast cancer risk (odds ratio per standard deviation of PRS, 1.36; 95% CI, 1.19 to 1.56; P = 8.6 × 10-6). Similarly, PRS that was based on 103 prostate cancer susceptibility variants was associated with prostate cancer risk (odds ratio per SD of PRS, 1.56; 95% CI, 1.35 to 1.81; P = 3.2 × 10-9). Large differences in absolute cancer risks were observed at the extremes of the PRS distribution. For example, prostate cancer risk by age 80 years at the 5th and 95th percentiles of the PRS varies from 7% to 26% for carriers of BRCA1 mutations and from 19% to 61% for carriers of BRCA2 mutations, respectively. Conclusion PRSs may provide informative cancer risk stratification for male carriers of BRCA1/2 mutations that might enable these men and their physicians to make informed decisions on the type and timing of breast and prostate cancer risk management.


Assuntos
Neoplasias da Mama Masculina/genética , Genes BRCA1 , Genes BRCA2 , Herança Multifatorial , Mutação , Neoplasias da Próstata/genética , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Predisposição Genética para Doença , Testes Genéticos , Estudo de Associação Genômica Ampla , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Medição de Risco/métodos
10.
Cancer ; 123(2): 210-218, 2017 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-27648926

RESUMO

BACKGROUND: Male breast cancer (MBC) is a rare disease whose etiology appears to be largely associated with genetic factors. BRCA1 and BRCA2 mutations account for about 10% of all MBC cases. Thus, a fraction of MBC cases are expected to be due to genetic factors not yet identified. To further explain the genetic susceptibility for MBC, whole-exome sequencing (WES) and targeted gene sequencing were applied to high-risk, BRCA1/2 mutation-negative MBC cases. METHODS: Germ-line DNA of 1 male and 2 female BRCA1/2 mutation-negative breast cancer (BC) cases from a pedigree showing a first-degree family history of MBC was analyzed with WES. Targeted gene sequencing for the validation of WES results was performed for 48 high-risk, BRCA1/2 mutation-negative MBC cases from an Italian multicenter study of MBC. A case-control series of 433 BRCA1/2 mutation-negative MBC and female breast cancer (FBC) cases and 849 male and female controls was included in the study. RESULTS: WES in the family identified the partner and localizer of BRCA2 (PALB2) c.419delA truncating mutation carried by the proband, her father, and her paternal uncle (all affected with BC) and the N-acetyltransferase 1 (NAT1) c.97C>T nonsense mutation carried by the proband's maternal aunt. Targeted PALB2 sequencing detected the c.1984A>T nonsense mutation in 1 of the 48 BRCA1/2 mutation-negative MBC cases. NAT1 c.97C>T was not found in the case-control series. CONCLUSIONS: These results add strength to the evidence showing that PALB2 is involved in BC risk for both sexes and indicate that consideration should be given to clinical testing of PALB2 for BRCA1/2 mutation-negative families with multiple MBC and FBC cases. Cancer 2017;123:210-218. © 2016 American Cancer Society.


Assuntos
Neoplasias da Mama Masculina/genética , Exoma/genética , Predisposição Genética para Doença/genética , Proteínas Nucleares/genética , Proteínas Supressoras de Tumor/genética , Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias da Mama/genética , Estudos de Casos e Controles , Análise Mutacional de DNA/métodos , Proteína do Grupo de Complementação N da Anemia de Fanconi , Feminino , Humanos , Itália , Masculino , Mutação/genética , Linhagem
11.
J Hum Genet ; 62(2): 309-315, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27829682

RESUMO

To determine prevalence, spectrum and genotype-phenotype correlations of MUTYH variants in Italian patients with suspected MAP (MUTYH-associated polyposis), a retrospective analysis was conducted to identify patients who had undergone MUTYH genetic testing from September 2002 to February 2014. Results of genetic testing and patient clinical characteristics were collected (gender, number of polyps, age at polyp diagnosis, presence of colorectal cancer (CRC) and/or other cancers, family data). The presence of large rearrangements of the MUTYH gene was evaluated by Multiplex Ligation-dependent Probe Amplification analysis. In all, 299 patients with colorectal neoplasia were evaluated: 61.2% were males, the median age at polyps or cancer diagnosis was 50 years (16-80 years), 65.2% had <100 polyps and 51.8% had CRC. A total of 36 different MUTYH variants were identified: 13 (36.1%) were classified as pathogenetic, whereas 23 (63.9%) were variants of unknown significance (VUS). Two pathogenetic variants were observed in 78 patients (26.1%). A large homozygous deletion of exon 15 was found in one patient (<1.0%). MAP patients were younger than those with negative MUTYH testing at polyps diagnosis (P<0.0001) and at first cancer diagnosis (P=0.007). MAP patients carrying the p.Glu480del variant presented with a younger age at polyp diagnosis as compared to patients carrying p.Gly396Asp and p.Tyr179Cys variants. A high heterogeneity of MUTYH variants and a high rate of VUS were identified in a cohort of Italian patients with suspected MAP. Genotype-phenotype analysis suggests that the p.Glu480del variant is associated with a severe phenotype.


Assuntos
Pólipos do Colo/genética , DNA Glicosilases/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Pólipos do Colo/patologia , Neoplasias Colorretais/genética , Feminino , Testes Genéticos , Genótipo , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Multiplex , Mutação , Fenótipo , Estudos Retrospectivos , Adulto Jovem
12.
Cancer Biol Ther ; 17(10): 1017-1021, 2016 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-27561088

RESUMO

We report an interesting clinical case of a patient carrying a specific BRCA2 germline variant affected by bone and hepatic metastases from a high grade uterine stromal sarcoma who obtained a complete metabolic response after only 3 cycles of trabectedin treatment (1.5 mg/m2 given intravenously over 24 hours every 21 days). Molecular investigations linked this outstanding positive pharmacological response with the loss of heterozygosity (LOH) of the mutated BRCA2 gene. These data support the hypothesis that the response to trabectedin may be positively conditioned by the different DNA repair defects present in the neoplasm and that BRCAness tumor genotype is important in determining the efficacy of trabectedin-based chemotherapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Proteína BRCA2/genética , Neoplasias do Endométrio/tratamento farmacológico , Neoplasias do Endométrio/genética , Mutação de Sentido Incorreto , Sarcoma do Estroma Endometrial/tratamento farmacológico , Sarcoma do Estroma Endometrial/genética , Sequência de Bases , Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/genética , Neoplasias Ósseas/secundário , Dioxóis/administração & dosagem , Neoplasias do Endométrio/diagnóstico por imagem , Neoplasias do Endométrio/patologia , Epirubicina/administração & dosagem , Feminino , Genes BRCA2 , Mutação em Linhagem Germinativa , Humanos , Ifosfamida/administração & dosagem , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/secundário , Pessoa de Meia-Idade , Sarcoma do Estroma Endometrial/diagnóstico por imagem , Sarcoma do Estroma Endometrial/patologia , Tetra-Hidroisoquinolinas/administração & dosagem , Trabectedina
13.
BMC Med Genet ; 17: 11, 2016 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-26852130

RESUMO

BACKGROUND: About 20 % of hereditary breast cancers are caused by mutations in BRCA1 and BRCA2 genes. Since BRCA1 and BRCA2 mutations may be spread throughout the gene, genetic testing is usually performed by direct sequencing of entire coding regions. In some populations, especially if relatively isolated, a few number of recurrent mutations is reported, sometimes caused by founder effect. METHODS: BRCA1 and BRCA2 screening for mutations was carried out on 1114 breast and/or ovarian cancer patients complying with the eligibility criteria for BRCA testing. Haplotype analysis was performed on the probands carrying recurrent mutations and their relatives, using two sets of microsatellite markers covering the BRCA1 (D17S588, D17S806, D17S902, D17S1325, D17S855, D17S1328, D17S800, and D17S250) and BRCA2 (D13S220, D13S267, D13S171, D13S1701, D13S1698, D13S260, D13S290, D13S1246) loci. The DMLE + 2.2 software was used to estimate the age of BRCA1 c.676delT and BRCA2 c.7806-2A > G. A multiplex PCR and two different primer extension assays were optimized and used for genotyping the recurrent mutations of the two genes. RESULTS: In the time frame of almost 20 years of genetic testing, we have found that five BRCA1 and three BRCA2 mutations are recurrent in a substantial subset of carriers from North-East Italy and neighboring Istria, where they represent more than 50 % of all mutations. Microsatellite analyses identified a common haplotype of different length for each mutation. Age estimation of BRCA1 c.676delT and BRCA2 c.7806-2A > G mutations revealed that they arose in the Friuli Venezia Giulia area about 86 and 94 generations ago, respectively. Suggestion of an association between BRCA2 c.7806-2A > G and risk of breast cancer in males has emerged. Finally, we developed a simple and efficient pre-screening test, performing an in-house primer extension SNaPshot® assay for the rapid identification of the eight recurrent mutations. CONCLUSIONS: Proofs of common ancestry has been obtained for the eight recurrent mutations. The observed genotype-phenotype correlation and the proposed rapid mutation detection strategy could improve the clinical management of breast and ovarian patients in North-East of Italy and neighboring geographic areas.


Assuntos
Proteína BRCA1/genética , Proteína BRCA2/genética , Análise Mutacional de DNA , Adulto , Idoso , Alelos , Neoplasias da Mama/genética , Estudos de Casos e Controles , Feminino , Efeito Fundador , Testes Genéticos , Estudo de Associação Genômica Ampla , Técnicas de Genotipagem , Haplótipos , Humanos , Itália , Masculino , Repetições de Microssatélites , Pessoa de Meia-Idade , Mutação , Neoplasias Ovarianas/genética , Adulto Jovem
14.
Cancer Genet ; 209(3): 107-11, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26797314

RESUMO

Turcot syndrome (TS) refers to the combination of colorectal polyps and primary tumours of the central nervous system. TS is a heterogeneous genetic condition due to APC and/or mismatch repair germline mutations. When APC is involved the vast majority of mutations are truncating, but in approximately 20%-30% of patients with familial polyposis no germline mutation can be found. A 30-year-old Caucasian woman with a positive pedigree for TS was referred to our Genetic Counselling Service. She was negative for APC and MUTYH but showed a reciprocal balanced translocation t(5;7)(q22;p15) at chromosome analysis. FISH analysis using specific BAC probes demonstrated that 5q22 breakpoint disrupted the APC gene. Transcript analysis by MLPA and digital PCR revealed that the cytogenetic rearrangement involving the 3' end of the APC gene caused a defective expression of a truncated transcript. This result allowed cytogenetic analysis to be offered to all the other family members and segregation analysis clearly demonstrated that all the carriers were affected, whereas non-carriers did not have the polyposis. A cytogenetic approach permitted the identification of the mutation-causing disease in this family, and the segregation analysis together with the transcript study supported the pathogenetic role of this mutation. Karyotype analysis was used as a predictive test in all members of this family. This family suggests that clinically positive TS and FAP cases, which test negative with standard molecular analysis, could be easily and cost-effectively resolved by a classical and molecular cytogenetic approach.


Assuntos
Neoplasias Encefálicas/genética , Cromossomos Humanos Par 5 , Cromossomos Humanos Par 7 , Neoplasias Colorretais/genética , Genes APC , Síndromes Neoplásicas Hereditárias/genética , Translocação Genética , Adulto , Feminino , Humanos , Cariotipagem
15.
Oncotarget ; 6(40): 42892-904, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26503472

RESUMO

The DNA glycosylase gene MBD4 safeguards genomic stability at CpG sites and is frequently mutated at coding poly-A tracks in mismatch repair (MMR)-defective colorectal tumors (CRC). Mbd4 biallelic inactivation in mice provided conflicting results as to its role in tumorigenesis. Thus, it is unclear whether MBD4 alterations are only secondary to MMR defects without functional consequences or can contribute to the mutator phenotype. We investigated MBD4 variants in a large series of hereditary/familial and sporadic CRC cases. Whereas MBD4 frameshifts were only detected in tumors, missense variants were found in both normal and tumor DNA. In CRC with double-MBD4/MMR and single-MBD4 variants, transition mutation frequency was increased, indicating that MBD4 defects may affect the mutational landscape independently of MMR defect. Mbd4-deficient mice showed reduced survival when combined with Mlh1-/- genotype. Taken together, these data suggest that MBD4 inactivation may contribute to tumorigenesis, acting as a modifier of MMR-deficient cancer phenotype.


Assuntos
Carcinogênese/genética , Neoplasias Colorretais/genética , Reparo de Erro de Pareamento de DNA/genética , Endodesoxirribonucleases/genética , Animais , Análise Mutacional de DNA , Feminino , Humanos , Masculino , Camundongos , Camundongos Knockout , Mutação , Análise de Sequência com Séries de Oligonucleotídeos , Fenótipo , Reação em Cadeia da Polimerase
16.
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
17.
Carcinogenesis ; 36(4): 452-8, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25742745

RESUMO

Lynch syndrome (LS) is an inherited predisposition cancer syndrome, typically caused by germline mutations in the mismatch repair genes MLH1, MSH2, MSH6 and PMS2. In the last years, a role for epimutations of the same genes has also been reported. MLH1 promoter methylation is a well known mechanism of somatic inactivation in tumors, and more recently, several cases of constitutional methylation have been identified. In four subjects affected by multiple tumors and belonging to a suspected LS family, we detected a novel secondary MLH1 gene epimutation. The methylation of MLH1 promoter was always linked in cis with a 997 bp-deletion (c.-168_c.116+713del), that removed exon 1 and partially involved the promoter of the same gene. Differently from cases with constitutional primary MLH1 inactivation, this secondary methylation was allele-specific and CpGs of the residual promoter region were totally methylated, leading to complete allele silencing. In the colon tumor of the proband, MLH1 and PMS2 expression was completely lost as a consequence of a pathogenic somatic point mutation (MLH1 c.199G>A, p.Gly67Arg) that also abrogated local methylation by destroying a CpG site. The evidences obtained highlight how MLH1 mutations and epimutations can reciprocally influence each other and suggest that an altered structure of the MLH1 locus results in epigenetic alteration.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Adenosina Trifosfatases/genética , Neoplasias Colorretais Hereditárias sem Polipose/genética , Metilação de DNA/genética , Enzimas Reparadoras do DNA/genética , Proteínas de Ligação a DNA/genética , Proteínas Nucleares/genética , Regiões Promotoras Genéticas/genética , Proteínas Adaptadoras de Transdução de Sinal/biossíntese , Adenosina Trifosfatases/biossíntese , Sequência de Bases , Reparo de Erro de Pareamento de DNA , Enzimas Reparadoras do DNA/biossíntese , Proteínas de Ligação a DNA/biossíntese , Feminino , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Humanos , Endonuclease PMS2 de Reparo de Erro de Pareamento , Proteína 1 Homóloga a MutL , Proteínas Nucleares/biossíntese , Análise de Sequência de DNA , Deleção de Sequência/genética
18.
Nat Genet ; 47(2): 164-71, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25581431

RESUMO

Genome-wide association studies (GWAS) have identified 12 epithelial ovarian cancer (EOC) susceptibility alleles. The pattern of association at these loci is consistent in BRCA1 and BRCA2 mutation carriers who are at high risk of EOC. After imputation to 1000 Genomes Project data, we assessed associations of 11 million genetic variants with EOC risk from 15,437 cases unselected for family history and 30,845 controls and from 15,252 BRCA1 mutation carriers and 8,211 BRCA2 mutation carriers (3,096 with ovarian cancer), and we combined the results in a meta-analysis. This new study design yielded increased statistical power, leading to the discovery of six new EOC susceptibility loci. Variants at 1p36 (nearest gene, WNT4), 4q26 (SYNPO2), 9q34.2 (ABO) and 17q11.2 (ATAD5) were associated with EOC risk, and at 1p34.3 (RSPO1) and 6p22.1 (GPX6) variants were specifically associated with the serous EOC subtype, all with P < 5 × 10(-8). Incorporating these variants into risk assessment tools will improve clinical risk predictions for BRCA1 and BRCA2 mutation carriers.


Assuntos
Proteína BRCA1/genética , Proteína BRCA2/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla/métodos , Neoplasias Epiteliais e Glandulares/genética , Neoplasias Ovarianas/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Adulto , Alelos , Carcinoma Epitelial do Ovário , Feminino , Genes Reporter , Genótipo , Heterozigoto , Humanos , Mutação , Locos de Características Quantitativas , Risco , Adulto Jovem
19.
Genome Biol ; 15(8): 437, 2014 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-25175524

RESUMO

BACKGROUND: Mismatch repair deficient colorectal adenomas are composed of transformed cells that descend from a common founder and progressively accumulate genomic alterations. The proliferation history of these tumors is still largely unknown. Here we present a novel approach to rebuild the proliferation trees that recapitulate the history of individual colorectal adenomas by mapping the progressive acquisition of somatic point mutations during tumor growth. RESULTS: Using our approach, we called high and low frequency mutations acquired in the X chromosome of four mismatch repair deficient colorectal adenomas deriving from male individuals. We clustered these mutations according to their frequencies and rebuilt the proliferation trees directly from the mutation clusters using a recursive algorithm. The trees of all four lesions were formed of a dominant subclone that co-existed with other genetically heterogeneous subpopulations of cells. However, despite this similar hierarchical organization, the growth dynamics varied among and within tumors, likely depending on a combination of tumor-specific genetic and environmental factors. CONCLUSIONS: Our study provides insights into the biological properties of individual mismatch repair deficient colorectal adenomas that may influence their growth and also the response to therapy. Extended to other solid tumors, our novel approach could inform on the mechanisms of cancer progression and on the best treatment choice.


Assuntos
Adenoma/genética , Cromossomos Humanos X/genética , Neoplasias Colorretais/genética , Reparo de Erro de Pareamento de DNA , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Sequência de DNA/métodos , Adenoma/patologia , Adulto , Idoso , Algoritmos , Evolução Clonal , Neoplasias Colorretais/patologia , Humanos , Pessoa de Meia-Idade , Taxa de Mutação
20.
Hum Mol Genet ; 23(14): 3843-52, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24569162

RESUMO

The MUTYH DNA glycosylase counteracts mutagenesis by removing adenine misincorporated opposite DNA 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG). Biallelic germline mutations in MUTYH cause the autosomal recessive MUTYH-associated polyposis (MAP). The impact on genetic instability of the p.Tyr179Cys and p.Arg245His MUTYH variants was evaluated in lymphoblastoid cell lines (LCLs) derived from MAP patients and their relatives in comparison to wild-type LCLs. No difference in MUTYH expression was identified between wild type and LCLs with the p.Tyr179Cys, while the p.Arg245His mutation was associated with an unstable MUTYH protein. LCLs homozygous for the p.Tyr179Cys or the p.Arg245His variant contained increased DNA 8-oxodG levels and exhibited a mutator phenotype at the PIG-A gene. The extent of the increased spontaneous mutation frequency was 3-fold (range 1.6- to 4.6-fold) in four independent LCLs carrying the p.Tyr179Cys variant, while a larger increase (6-fold) was observed in two p.Arg245His LCLs. A similar hypermutability and S-phase delay following treatment with KBrO3 was observed in LCLs homozygous for either variant. When genetic instability was investigated in monoallelic p.Arg245His carriers, mutant frequencies showed an increase which is intermediate between wild-type and homozygous cells, whereas the mutator effect in heterozygous p.Tyr179Cys LCLs was similar to that in homozygotes. These findings indicate that the type of MUTYH mutation can affect the extent of genome instability associated with MUTYH inactivation. In addition, the mild spontaneous mutator phenotype observed in monoallelic carriers highlights the biological importance of this gene in the protection of the genome against endogenous DNA damage.


Assuntos
Polipose Adenomatosa do Colo/genética , DNA Glicosilases/genética , DNA Glicosilases/metabolismo , Instabilidade Genômica , Polipose Adenomatosa do Colo/sangue , Adulto , Bromatos/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Desoxiguanosina/análogos & derivados , Desoxiguanosina/análise , Variação Genética , Humanos , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Estabilidade Proteica , Adulto Jovem
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