Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 104
Filtrar
1.
Eur J Cancer Care (Engl) ; : e13173, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31571365

RESUMO

BACKGROUND: We performed a comprehensive assessment of the psychometrics of the "Psychosocial Aspects in Hereditary Cancer" (PAHC) questionnaire in French, German and Spanish. METHODS: Women consecutively approached in Cancer Genetic Clinics completed the PAHC, distress and satisfaction questionnaires at pre-testing (T1) and after test result disclosure (T2). In addition to standard psychometric attributes, we assessed the PAHC ability to respond to change (i.e. improvement or deterioration from T1 to T2) in perceived difficulties and computed minimal important differences (MID) in PAHC scores as compared with self-reported needs for additional counselling. RESULTS: Of 738 eligible counselees, 214 (90%) in France (Paris), 301 (92%) in Germany (Cologne) and 133 (77%) in Spain (Barcelona) completed the PAHC. A six-factor revised PAHC model yielded acceptable CFA goodness-of-fit indexes and good all scales internal consistencies. PAHC scales demonstrated expected conceptual differences with distress and satisfaction with counselling. Different levels of psychosocial difficulties were evidenced between counselees' subgroups and over time (p-values < .05). MID estimates ranged from 8 to 15 for improvement and 9 to 21 for deterioration. CONCLUSION: The PAHC French, German and Spanish versions are reliable and valid for evaluating the psychosocial difficulties of women at high BC risk attending genetic clinics.

3.
J Med Genet ; 2019 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-31494577

RESUMO

INTRODUCTION: Lynch syndrome (LS) and constitutional mismatch repair deficiency (CMMRD) are hereditary cancer syndromes associated with mismatch repair (MMR) deficiency. Tumours show microsatellite instability (MSI), also reported at low levels in non-neoplastic tissues. Our aim was to evaluate the performance of high-sensitivity MSI (hs-MSI) assessment for the identification of LS and CMMRD in non-neoplastic tissues. MATERIALS AND METHODS: Blood DNA samples from 131 individuals were grouped into three cohorts: baseline (22 controls), training (11 CMMRD, 48 LS and 15 controls) and validation (18 CMMRD and 18 controls). Custom next generation sequencing panel and bioinformatics pipeline were used to detect insertions and deletions in microsatellite markers. An hs-MSI score was calculated representing the percentage of unstable markers. RESULTS: The hs-MSI score was significantly higher in CMMRD blood samples when compared with controls in the training cohort (p<0.001). This finding was confirmed in the validation set, reaching 100% specificity and sensitivity. Higher hs-MSI scores were detected in biallelic MSH2 carriers (n=5) compared with MSH6 carriers (n=15). The hs-MSI analysis did not detect a difference between LS and control blood samples (p=0.564). CONCLUSIONS: The hs-MSI approach is a valuable tool for CMMRD diagnosis, especially in suspected patients harbouring MMR variants of unknown significance or non-detected biallelic germline mutations.

4.
BMJ Open ; 9(9): e029926, 2019 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-31551380

RESUMO

OBJECTIVES AND SETTING: Advances in multigene panel testing for cancer susceptibility has increased the complexity of counselling, requiring particular attention to counselees' psychosocial needs. Changes in psychosocial problems before and after genetic testing were prospectively compared between genetic test results in women tested for breast or ovarian cancer genetic susceptibility in French, German and Spanish clinics. PARTICIPANTS AND MEASURES: Among 752 counselees consecutively approached, 646 (86%) were assessed after the initial genetic consultation (T1), including 510 (68%) affected with breast cancer, of which 460 (61%) were assessed again after receiving the test result (T2), using questionnaires addressing genetic-specific psychosocial problems (Psychosocial Aspects of Hereditary Cancer (PAHC)-six scales). Sociodemographic and clinical data were also collected. RESULTS: Seventy-nine (17.2%), 19 (4.1%), 259 (56.3%), 44 (9.6%) and 59 (12.8%) women received a BRCA1/2, another high/moderate-risk pathogenic variant (PV), negative uninformative, true negative (TN) or variant of uncertain significance result (VUS), respectively. On multiple regression analyses, compared with women receiving another result, those with a VUS decreased more in psychosocial problems related to hereditary predisposition (eg, coping with the test result) (ß=-0.11, p<0.05) and familial/social issues (eg, risk communication) (ß=-0.13, p<0.05), almost independently from their problems before testing. Women with a PV presented no change in hereditary predisposition problems and, so as women with a TN result, a non-significant increase in familial/social issues. Other PAHC scales (ie, emotions, familial cancer, personal cancer and children-related issues) were not affected by genetic testing. CONCLUSIONS: In women tested for breast or ovarian cancer genetic risk in European genetics clinics, psychosocial problems were mostly unaffected by genetic testing. Apart from women receiving a VUS result, those with another test result presented unchanged needs in counselling in particular about hereditary predisposition and familial/social issues.

5.
Cancer Epidemiol ; 61: 129-132, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31238232

RESUMO

INTRODUCTION: The current availability of genomic information represents an opportunity to develop new strategies for early detection of cancer. New molecular tests for endometrial cancer may improve performance and failure rates of histological aspirate-based diagnosis, and provide promising perspectives for a potential screening scenario. However, the selection of relevant biomarkers to develop efficient strategies can be a challenge. MATERIALS AND METHODS: We developed an algorithm to identify the largest number of patients with endometrial cancer using the minimum number of somatic mutations based on The Cancer Genome Atlas (TCGA) dataset. RESULTS: The algorithm provided the number of subjects with mutations (sensitivity) for a given number of biomarkers included in the signature. For instance, by evaluating the 50 most representative point mutations, up to 81.9% of endometrial cancers can be identified in the TCGA dataset. At gene level, a 92.9% sensitivity can be obtained by interrogating five genes. DISCUSSION: We developed a computational method to aid in the selection of relevant genomic biomarkers in endometrial cancer that can be adapted to other cancer types or diseases.

6.
Food Chem Toxicol ; 131: 110529, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31150784

RESUMO

The health promoting effects of extra virgin olive oil (EVOO) relate to its unique repertoire of phenolic compounds. Here, we used a chemoinformatics approach to computationally identify endogenous ligands and assign putative biomolecular targets to oleacein, one of the most abundant secoiridoids in EVOO. Using a structure-based virtual profiling software tool and reference databases containing more than 9000 binding sites protein cavities, we identified 996 putative oleacein targets involving more than 700 proteins. We subsequently identified the high-level functions of oleacein in terms of biomolecular interactions, signaling pathways, and protein-protein interaction (PPI) networks. Delineation of the oleacein target landscape revealed that the most significant modules affected by oleacein were associated with metabolic processes (e.g., glucose and lipid metabolism) and chromatin-modifying enzymatic activities (i.e., histone post-translational modifications). We experimentally confirmed that, in a low-micromolar physiological range (<20 µmol/l), oleacein was capable of inhibiting the catalytic activities of predicted metabolic and epigenetic targets including nicotinamide N-methyltransferase, ATP-citrate lyase, lysine-specific demethylase 6A, and N-methyltransferase 4. Our computational de-orphanization of oleacein provides new mechanisms through which EVOO biophenols might operate as chemical prototypes capable of modulating the biologic machinery of healthy aging.


Assuntos
Aldeídos/metabolismo , Fenóis/metabolismo , Proteômica/métodos , ATP Citrato (pro-S)-Liase/química , ATP Citrato (pro-S)-Liase/metabolismo , Aldeídos/química , Domínio Catalítico , Ensaios Enzimáticos , Epigenômica/métodos , Ontologia Genética/estatística & dados numéricos , Histona Desmetilases/química , Histona Desmetilases/metabolismo , Humanos , Informática/métodos , Metiltransferases/química , Metiltransferases/metabolismo , Simulação de Acoplamento Molecular , Nicotinamida N-Metiltransferase/química , Nicotinamida N-Metiltransferase/metabolismo , Olea/química , Azeite de Oliva/química , Fenóis/química , Ligação Proteica , Mapeamento de Interação de Proteínas , Software
7.
Br J Cancer ; 121(2): 180-192, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31213659

RESUMO

BACKGROUND: Height and body mass index (BMI) are associated with higher ovarian cancer risk in the general population, but whether such associations exist among BRCA1/2 mutation carriers is unknown. METHODS: We applied a Mendelian randomisation approach to examine height/BMI with ovarian cancer risk using the Consortium of Investigators for the Modifiers of BRCA1/2 (CIMBA) data set, comprising 14,676 BRCA1 and 7912 BRCA2 mutation carriers, with 2923 ovarian cancer cases. We created a height genetic score (height-GS) using 586 height-associated variants and a BMI genetic score (BMI-GS) using 93 BMI-associated variants. Associations were assessed using weighted Cox models. RESULTS: Observed height was not associated with ovarian cancer risk (hazard ratio [HR]: 1.07 per 10-cm increase in height, 95% confidence interval [CI]: 0.94-1.23). Height-GS showed similar results (HR = 1.02, 95% CI: 0.85-1.23). Higher BMI was significantly associated with increased risk in premenopausal women with HR = 1.25 (95% CI: 1.06-1.48) and HR = 1.59 (95% CI: 1.08-2.33) per 5-kg/m2 increase in observed and genetically determined BMI, respectively. No association was found for postmenopausal women. Interaction between menopausal status and BMI was significant (Pinteraction < 0.05). CONCLUSION: Our observation of a positive association between BMI and ovarian cancer risk in premenopausal BRCA1/2 mutation carriers is consistent with findings in the general population.

8.
Int J Cancer ; 145(12): 3194-3206, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31199503

RESUMO

Due to the anatomical continuity of the uterine cavity with the cervix, genomic exploitation of material from routine Pap smears and other noninvasive sampling methods represent a unique opportunity to detect signs of disease using biological material shed from the upper genital tract. Recent research findings offer a promising perspective in the detection of endometrial cancer, but certain questions need to be addressed in order to accelerate the implementation of novel technologies in a routine screening or clinical setting. We discuss here new perspectives on detection of endometrial cancer using genomic and other biomarkers in minimally invasive sampling methods with a special focus on public health classic screening criteria, highlighting current gaps in knowledge.

9.
Hum Mutat ; 40(11): 1910-1923, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31243857

RESUMO

Technological advances have allowed the identification of new adenomatous and serrated polyposis genes, and of several candidate genes that require additional supporting evidence of causality. Through an exhaustive literature review and mutational screening of 177 unrelated polyposis patients, we assessed the involvement of MCM9, FOCAD, POLQ, and RNF43 in the predisposition to (nonserrated) colonic polyposis, as well as the prevalence of NTHL1 and MSH3 mutations among genetically unexplained polyposis patients. Our results, together with previously reported data and mutation frequency in controls, indicate that: MCM9 and POLQ mutations are not associated with polyposis; germline RNF43 mutations, with a prevalence of 1.5-2.5% among serrated polyposis patients, do not cause nonserrated polyposis; MSH3 biallelic mutations are highly infrequent among European polyposis patients, and the prevalence of NTHL1 biallelic mutations among unexplained polyposes is ~2%. Although nonsignificant, FOCAD predicted deleterious variants are overrepresented in polyposis patients compared to controls, warranting larger studies to provide definite evidence in favor or against their causal association with polyposis predisposition.

10.
Sci Rep ; 9(1): 9020, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31227763

RESUMO

The cancer-predisposing syndrome caused by biallelic mutations in NTHL1 may not be a solely colorectal cancer (CRC) and polyposis syndrome but rather a multi-tumor recessive disease. The presence of ≤10 adenomas in several mutation carriers suggests a possible causal role of NTHL1 in hereditary or early-onset nonpolyposis CRC. The involvement of NTHL1 in serrated/hyperplastic polyposis remains unexplored. The aim of our study is to elucidate the role of NTHL1 in the predisposition to personal or familial history of multiple tumor types, familial/early-onset nonpolyposis CRC, and serrated polyposis. NTHL1 mutational screening was performed in 312 cancer patients with personal or family history of multiple tumor types, 488 with hereditary nonpolyposis CRC, and 96 with serrated/hyperplastic polyposis. While no biallelic mutation carriers were identified in patients with personal and/or family history of multiple tumor types or with serrated polyposis, one was identified among the 488 nonpolyposis CRC patients. The carrier of c.268C>T (p.Q90*) and 550-1G>A was diagnosed with CRC and meningioma at ages 37 and 45 respectively, being reclassified as attenuated adenomatous polyposis after the cumulative detection of 26 adenomas. Our findings suggest that biallelic mutations in NTHL1 rarely cause CRC, a personal/familial multi-tumor history, or serrated polyposis, in absence of adenomas.

11.
Hum Mutat ; 40(9): 1557-1578, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31131967

RESUMO

The multifactorial likelihood analysis method has demonstrated utility for quantitative assessment of variant pathogenicity for multiple cancer syndrome genes. Independent data types currently incorporated in the model for assessing BRCA1 and BRCA2 variants include clinically calibrated prior probability of pathogenicity based on variant location and bioinformatic prediction of variant effect, co-segregation, family cancer history profile, co-occurrence with a pathogenic variant in the same gene, breast tumor pathology, and case-control information. Research and clinical data for multifactorial likelihood analysis were collated for 1,395 BRCA1/2 predominantly intronic and missense variants, enabling classification based on posterior probability of pathogenicity for 734 variants: 447 variants were classified as (likely) benign, and 94 as (likely) pathogenic; and 248 classifications were new or considerably altered relative to ClinVar submissions. Classifications were compared with information not yet included in the likelihood model, and evidence strengths aligned to those recommended for ACMG/AMP classification codes. Altered mRNA splicing or function relative to known nonpathogenic variant controls were moderately to strongly predictive of variant pathogenicity. Variant absence in population datasets provided supporting evidence for variant pathogenicity. These findings have direct relevance for BRCA1 and BRCA2 variant evaluation, and justify the need for gene-specific calibration of evidence types used for variant classification.

12.
Aging (Albany NY) ; 11(9): 2874-2888, 2019 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-31076561

RESUMO

Certain dietary interventions might improve the therapeutic index of cancer treatments. An alternative to the "drug plus diet" approach is the pharmacological reproduction of the metabolic traits of such diets. Here we explored the impact of adding metformin to an established therapeutic regimen on the systemic host metabolism of cancer patients. A panel of 11 serum metabolites including markers of mitochondrial function and intermediates/products of folate-dependent one-carbon metabolism were measured in paired baseline and post-treatment sera obtained from HER2-positive breast cancer patients randomized to receive either metformin combined with neoadjuvant chemotherapy and trastuzumab or an equivalent regimen without metformin. Metabolite profiles revealed a significant increase of the ketone body ß-hydroxybutyrate and of the TCA intermediate α-ketoglutarate in the metformin-containing arm. A significant relationship was found between the follow-up levels of homocysteine and the ability of treatment arms to achieve a pathological complete response (pCR). In the metformin-containing arm, patients with significant elevations of homocysteine tended to have a higher probability of pCR. The addition of metformin to an established anti-cancer therapeutic regimen causes a fasting-mimicking modification of systemic host metabolism. Circulating homocysteine could be explored as a clinical pharmacodynamic biomarker linking the antifolate-like activity of metformin and biological tumor response.

13.
Food Chem Toxicol ; 128: 35-45, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30935952

RESUMO

Catechol-containing polyphenols present in coffee and tea, while serving as excellent substrates for catechol-O-methyltransferase (COMT)-catalyzed O-methylation, can also operate as COMT inhibitors. However, little is known about the relationship between COMT and the characteristic phenolics present in extra virgin olive oil (EVOO). We here selected the EVOO dihydroxy-phenol oleacein for a computational study of COMT-driven methylation using classic molecular docking/molecular dynamics simulations and hybrid quantum mechanical/molecular mechanics, which were supported by in vitro activity studies using human COMT. Oleacein could be superimposed onto the catechol-binding site of COMT, maintaining the interactions with the atomic positions involved in methyl transfer from the S-adenosyl-L-methionine cofactor. The transition state structure for the meta-methylation in the O5 position of the oleacein benzenediol moiety was predicted to occur preferentially. Enzyme analysis of the conversion ratio of catechol to O-alkylated guaiacol confirmed the inhibitory effect of oleacein on human COMT, which remained unaltered when tested against the protein version encoded by the functional Val158Met polymorphism of the COMT gene. Our study provides a theoretical determination of how EVOO dihydroxy-phenols can be metabolized via COMT. The ability of oleacein to inhibit COMT adds a new dimension to the physiological and therapeutic utility of EVOO secoiridoids.


Assuntos
Aldeídos/farmacologia , Inibidores de Catecol O-Metiltransferase/farmacologia , Catecol O-Metiltransferase/metabolismo , Azeite de Oliva/química , Fenóis/farmacologia , Aldeídos/isolamento & purificação , Catecol O-Metiltransferase/genética , Catecóis/metabolismo , Humanos , Metionina/genética , Metilação , Simulação de Acoplamento Molecular , Fenóis/isolamento & purificação , Polimorfismo Genético , Especificidade por Substrato , Valina/genética
14.
Int J Cancer ; 145(10): 2682-2691, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30927264

RESUMO

Multigene panels provide a powerful tool for analyzing several genes simultaneously. We evaluated the frequency of pathogenic variants (PV) in customized predefined panels according to clinical suspicion by phenotype and compared it to the yield obtained in the analysis of our clinical research gene panel. We also investigated mutational yield of opportunistic testing of BRCA1/2 and mismatch repair (MMR) genes in all patients. A total of 1,205 unrelated probands with clinical suspicion of hereditary cancer were screened for germline mutations using panel testing. Overall, 1,048 females and 157 males were analyzed, mean age at cancer diagnosis was 48; 883 had hereditary breast/ovarian cancer-suspicion, 205 hereditary nonpolyposis colorectal cancer (HNPCC)-suspicion, 73 adenomatous-polyposis-suspicion and 44 with other/multiple clinical criteria. At least one PV was found in 150 probands (12%) analyzed by our customized phenotype-driven panel. Tumoral MMR deficiency predicted for the presence of germline MMR gene mutations in patients with HNPCC-suspicion (46/136 vs. 0/56 in patients with and without MMR deficiency, respectively). Opportunistic testing additionally identified five MSH6, one BRCA1 and one BRCA2 carriers (0.6%). The analysis of the extended 24-gene panel provided 25 additional PVs (2%), including in 4 out of 51 individuals harboring MMR-proficient colorectal tumors (2 CHEK2 and 2 ATM). Phenotype-based panels provide a notable rate of PVs with clinical actionability. Opportunistic testing of MMR and BRCA genes leads to a significant straightforward identification of MSH6, BRCA1 and BRCA2 mutation carriers, and endorses the model of opportunistic testing of genes with clinical utility within a standard genetic counseling framework.

15.
Nat Commun ; 10(1): 431, 2019 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-30683880

RESUMO

Quantifying the genetic correlation between cancers can provide important insights into the mechanisms driving cancer etiology. Using genome-wide association study summary statistics across six cancer types based on a total of 296,215 cases and 301,319 controls of European ancestry, here we estimate the pair-wise genetic correlations between breast, colorectal, head/neck, lung, ovary and prostate cancer, and between cancers and 38 other diseases. We observed statistically significant genetic correlations between lung and head/neck cancer (rg = 0.57, p = 4.6 × 10-8), breast and ovarian cancer (rg = 0.24, p = 7 × 10-5), breast and lung cancer (rg = 0.18, p =1.5 × 10-6) and breast and colorectal cancer (rg = 0.15, p = 1.1 × 10-4). We also found that multiple cancers are genetically correlated with non-cancer traits including smoking, psychiatric diseases and metabolic characteristics. Functional enrichment analysis revealed a significant excess contribution of conserved and regulatory regions to cancer heritability. Our comprehensive analysis of cross-cancer heritability suggests that solid tumors arising across tissues share in part a common germline genetic basis.


Assuntos
Neoplasias da Mama/genética , Neoplasias Colorretais/genética , Neoplasias de Cabeça e Pescoço/genética , Padrões de Herança , Neoplasias Pulmonares/genética , Neoplasias Ovarianas/genética , Neoplasias da Próstata/genética , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/etnologia , Neoplasias da Mama/patologia , Estudos de Casos e Controles , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/etnologia , Neoplasias Colorretais/patologia , Grupo com Ancestrais do Continente Europeu , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Neoplasias de Cabeça e Pescoço/diagnóstico , Neoplasias de Cabeça e Pescoço/etnologia , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/etnologia , Neoplasias Pulmonares/patologia , Masculino , Transtornos Mentais/etnologia , Transtornos Mentais/genética , Transtornos Mentais/fisiopatologia , Proteínas de Neoplasias/genética , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/etnologia , Neoplasias Ovarianas/patologia , Fenótipo , Polimorfismo de Nucleotídeo Único , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/etnologia , Neoplasias da Próstata/patologia , Fumar/etnologia , Fumar/genética , Fumar/fisiopatologia
16.
Cancer Lett ; 447: 86-92, 2019 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-30677446

RESUMO

Somatic epigenetic inactivation of the DNA repair protein O6-methylguanine DNA methyltransferase (MGMT) is frequent in colorectal cancer (CRC); however, its involvement in CRC predisposition remains unexplored. We assessed the role and relevance of MGMT germline mutations and epimutations in familial and early-onset CRC. Mutation and promoter methylation screenings were performed in 473 familial and/or early-onset mismatch repair-proficient nonpolyposis CRC cases. No constitutional MGMT inactivation by promoter methylation was observed. Of six rare heterozygous germline variants identified, c.346C > T (p.H116Y) and c.476G > A (p.R159Q), detected in three and one families respectively, affected highly conserved residues and showed segregation with cancer in available family members. In vitro, neither p.H116Y nor p.R159Q caused statistically significant reduction of MGMT repair activity. No evidence of somatic second hits was found in the studied tumors. Case-control data showed over-representation of c.346C > T (p.H116Y) in familial CRC compared to controls, but no overall association of MGMT mutations with CRC predisposition. In conclusion, germline mutations and constitutional epimutations in MGMT are not major players in hereditary CRC. Nevertheless, the over-representation of c.346C > T (p.H116Y) in our familial CRC cohort warrants further research.

17.
J Med Genet ; 56(8): 521-525, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30580288

RESUMO

IMPORTANCE: Genetic testing of hereditary cancer using comprehensive gene panels can identify patients with more than one pathogenic mutation in high and/or moderate-risk-associated cancer genes. This phenomenon is known as multilocus inherited neoplasia alleles syndrome (MINAS), which has been potentially linked to more severe clinical manifestations. OBJECTIVE: To determine the prevalence and clinical features of MINAS in a large cohort of adult patients with hereditary cancer homogeneously tested with the same gene panel. PATIENTS AND METHODS: A cohort of 1023 unrelated patients with suspicion of hereditary cancer was screened using a validated panel including up to 135 genes associated with hereditary cancer and phakomatoses. RESULTS: Thirteen (1.37%) patients harbouring two pathogenic mutations in dominant cancer-predisposing genes were identified, representing 5.7% (13/226) of patients with pathogenic mutations. Most (10/13) of these cases presented clinical manifestations associated with only one of the mutations identified. One case showed mutations in MEN1 and MLH1 and developed tumours associated with both cancer syndromes. Interestingly, three of the double mutants had a young age of onset or severe breast cancer phenotype and carried mutations in moderate to low-risk DNA damage repair-associated genes; two of them presented biallelic inactivation of CHEK2. We included these two patients for the sake of their clinical interest although we are aware that they do not exactly fulfil the definition of MINAS since both mutations are in the same gene. CONCLUSIONS AND RELEVANCE: Genetic analysis of a broad cancer gene panel identified the largest series of patients with MINAS described in a single study. Overall, our data do not support the existence of more severe manifestations in double mutants at the time of diagnosis although they do confirm previous evidence of severe phenotype in biallelic CHEK2 and other DNA repair cancer-predisposing genes.

18.
Artigo em Inglês | MEDLINE | ID: mdl-30459716

RESUMO

Metformin has been proposed to operate as an agonist of SIRT1, a nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase that mimics most of the metabolic responses to calorie restriction. Herein, we present an in silico analysis focusing on the molecular docking and dynamic simulation of the putative interactions between metformin and SIRT1. Using eight different crystal structures of human SIRT1 protein, our computational approach was able to delineate the putative binding modes of metformin to several pockets inside and outside the central deacetylase catalytic domain. First, metformin was predicted to interact with the very same allosteric site occupied by resveratrol and other sirtuin-activating compounds (STATCs) at the amino-terminal activation domain of SIRT1. Second, metformin was predicted to interact with the NAD+ binding site in a manner slightly different to that of SIRT1 inhibitors containing an indole ring. Third, metformin was predicted to interact with the C-terminal regulatory segment of SIRT1 bound to the NAD+ hydrolysis product ADP-ribose, a "C-pocket"-related mechanism that appears to be essential for mechanism-based activation of SIRT1. Enzymatic assays confirmed that the net biochemical effect of metformin and other biguanides such as a phenformin was to improve the catalytic efficiency of SIRT1 operating in conditions of low NAD+ in vitro. Forthcoming studies should confirm the mechanistic relevance of our computational insights into how the putative binding modes of metformin to SIRT1 could explain its ability to operate as a direct SIRT1-activating compound. These findings might have important implications for understanding how metformin might confer health benefits via maintenance of SIRT1 activity during the aging process when NAD+ levels decline.

19.
Hum Mutat ; 2018 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-30362666

RESUMO

We describe a family in which four siblings exhibited multiple or classic colonic polyposis with or without colorectal carcinoma (CRC). One female developed three primary tumors, including CRC and carcinomas of the ovary and breast. Whole-exome sequencing of germline DNA from affected and unaffected individuals revealed a novel missense mutation in the exonuclease domain of POLE (c.833C>A; p.Thr278Lys) associated with a highly penetrant, autosomal-dominant inheritance pattern. Functional studies in yeast and demonstration of a high mutational burden in the available tumors confirmed the pathogenicity of the novel variant. Prominent POLE-deficient somatic mutational signatures were seen in the CRCs, but in contrast, a mutational signature typical of concomitant tumoral loss of POLE and mismatch-repair function (POLE-exo* /MSI) was noted in the breast cancer. The breast cancer also showed distinctive pathological characteristics that reflect the presence of both the germline POLE variant and the secondary somatic MMR alterations.

20.
J Natl Cancer Inst ; 2018 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-30312457

RESUMO

Background: BRCA1/2 mutations confer high lifetime risk of breast cancer, although other factors may modify this risk. Whether height or body mass index (BMI) modifies breast cancer risk in BRCA1/2 mutation carriers remains unclear. Methods: We used Mendelian randomization approaches to evaluate the association of height and BMI on breast cancer risk, using data from the Consortium of Investigators of Modifiers of BRCA1/2 with 14 676 BRCA1 and 7912 BRCA2 mutation carriers, including 11 451 cases of breast cancer. We created a height genetic score using 586 height-associated variants and a BMI genetic score using 93 BMI-associated variants. We examined both observed and genetically determined height and BMI with breast cancer risk using weighted Cox models. All statistical tests were two-sided. Results: Observed height was positively associated with breast cancer risk (HR = 1.09 per 10 cm increase, 95% confidence interval [CI] = 1.0 to 1.17; P = 1.17). Height genetic score was positively associated with breast cancer, although this was not statistically significant (per 10 cm increase in genetically predicted height, HR = 1.04, 95% CI = 0.93 to 1.17; P = .47). Observed BMI was inversely associated with breast cancer risk (per 5 kg/m2 increase, HR = 0.94, 95% CI = 0.90 to 0.98; P = .007). BMI genetic score was also inversely associated with breast cancer risk (per 5 kg/m2 increase in genetically predicted BMI, HR = 0.87, 95% CI = 0.76 to 0.98; P = .02). BMI was primarily associated with premenopausal breast cancer. Conclusion: Height is associated with overall breast cancer and BMI is associated with premenopausal breast cancer in BRCA1/2 mutation carriers. Incorporating height and BMI, particularly genetic score, into risk assessment may improve cancer management.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA