Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Med Genet ; 61(5): 483-489, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38160042

RESUMO

BACKGROUND: BRCA1/2 testing is crucial to guide clinical decisions in patients with hereditary breast/ovarian cancer, but detection of variants of uncertain significance (VUSs) prevents proper management of carriers. The ENIGMA (Evidence-based Network for the Interpretation of Germline Mutant Alleles) BRCA1/2 Variant Curation Expert Panel (VCEP) has recently developed BRCA1/2 variant classification guidelines consistent with ClinGen processes, specified against the ACMG/AMP (American College of Medical Genetics and Genomics/Association for Molecular-Pathology) classification framework. METHODS: The ClinGen-approved BRCA1/2-specified ACMG/AMP classification guidelines were applied to BRCA1/2 VUSs identified from 2011 to 2022 in a series of patients, retrieving information from the VCEP documentation, public databases, literature and ENIGMA unpublished data. Then, we critically re-evaluated carrier families based on new results and checked consistency of updated classification with main sources for clinical interpretation of BRCA1/2 variants. RESULTS: Among 166 VUSs detected in 231 index cases, 135 (81.3%) found in 197 index cases were classified by applying BRCA1/2-specified ACMG/AMP criteria: 128 (94.8%) as Benign/Likely Benign and 7 (5.2%) as Pathogenic/Likely Pathogenic. The average time from the first report as 'VUS' to classification using this approach was 49.4 months. Considering that 15 of these variants found in 64 families had already been internally reclassified prior to this work, this study provided 121 new reclassifications among the 151 (80.1%) remaining VUSs, relevant to 133/167 (79.6%) families. CONCLUSIONS: These results demonstrated the effectiveness of new BRCA1/2 ACMG/AMP classification guidelines for VUS classification within a clinical cohort, and their important clinical impact. Furthermore, they suggested a cadence of no more than 3 years for regular review of VUSs, which however requires time, expertise and resources.


Assuntos
Proteína BRCA1 , Proteína BRCA2 , Neoplasias da Mama , Variação Genética , Humanos , Proteína BRCA1/genética , Proteína BRCA2/genética , Predisposição Genética para Doença , Testes Genéticos/métodos
2.
Int J Mol Sci ; 24(10)2023 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-37240284

RESUMO

Despite significant therapeutic advances, metastatic CRPC (mCRPC) remains a lethal disease. Mutations in homologous recombination repair (HRR) genes are frequent in mCRPC, and tumors harboring these mutations are known to be sensitive to PARP inhibitors. The aim of this study was to verify the technical effectiveness of this panel in the analysis of mCRPC, the frequency and type of mutations in the BRCA1/BRCA2 genes, as well as in the homologous recombination repair (HRR) genes. A total of 50 mCRPC cases were analyzed using a multi-gene next-generation sequencing panel evaluating a total of 1360 amplicons in 24 HRR genes. Of the 50 cases, 23 specimens (46.0%) had an mCRPC harboring a pathogenic variant or a variant of uncertain significance (VUS), whereas in 27 mCRPCs (54.0%), no mutations were detected (wild-type tumors). BRCA2 was the most commonly mutated gene (14.0% of samples), followed by ATM (12.0%), and BRCA1 (6.0%). In conclusion, we have set up an NGS multi-gene panel that is capable of analyzing BRCA1/BRCA2 and HRR alterations in mCRPC. Moreover, our clinical algorithm is currently being used in clinical practice for the management of patients with mCRPC.


Assuntos
Genes BRCA2 , Neoplasias de Próstata Resistentes à Castração , Masculino , Humanos , Neoplasias de Próstata Resistentes à Castração/patologia , Reparo de DNA por Recombinação/genética , Mutação em Linhagem Germinativa , Biomarcadores Tumorais/genética , Sequenciamento de Nucleotídeos em Larga Escala , Proteína BRCA1/genética , Proteína BRCA2/genética
3.
Biomedicines ; 11(3)2023 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-36979683

RESUMO

Hearing loss is the most frequent sensorineural disorder, affecting approximately 1:1000 newborns. Hereditary forms (HHL) represent 50-60% of cases, highlighting the relevance of genetic testing in deaf patients. HHL is classified as non-syndromic (NSHL-70% of cases) or syndromic (SHL-30% of cases). In this study, a multistep and integrative approach aimed at identifying the molecular cause of HHL in 102 patients, whose GJB2 analysis already showed a negative result, is described. In NSHL patients, multiplex ligation probe amplification and long-range PCR analyses of the STRC gene solved 13 cases, while whole exome sequencing (WES) identified the genetic diagnosis in 26 additional ones, with a total detection rate of 47.6%. Concerning SHL, WES detected the molecular cause in 55% of cases. Peculiar findings are represented by the identification of four subjects displaying a dual molecular diagnosis and eight affected by non-syndromic mimics, five of them presenting Usher syndrome type 2. Overall, this study provides a detailed characterisation of the genetic causes of HHL in the Italian population. Furthermore, we highlighted the frequency of Usher syndrome type 2 carriers in the Italian population to pave the way for a more effective implementation of diagnostic and follow-up strategies for this disease.

4.
Cancers (Basel) ; 15(5)2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36900320

RESUMO

BRCA testing is recommended in all Ovarian Cancer (OC) patients, but the optimal approach is debated. The landscape of BRCA alterations was explored in 30 consecutive OC patients: 6 (20.0%) carried germline pathogenic variants, 1 (3.3%) a somatic mutation of BRCA2, 2 (6.7%) unclassified germline variants in BRCA1, and 5 (16.7%) hypermethylation of the BRCA1 promoter. Overall, 12 patients (40.0%) showed BRCA deficit (BD), due to inactivation of both alleles of either BRCA1 or BRCA2, while 18 (60.0%) had undetected/unclear BRCA deficit (BU). Regarding sequence changes, analysis performed on Formalin-Fixed-Paraffin-Embedded tissue through a validated diagnostic protocol showed 100% accuracy, compared with 96.3% for Snap-Frozen tissue and 77.8% for the pre-diagnostic Formalin-Fixed-Paraffin-Embedded protocol. BD tumors, compared to BU, showed a significantly higher rate of small genomic rearrangements. After a median follow-up of 60.3 months, the mean PFS was 54.9 ± 27.2 months in BD patients and 34.6 ± 26.7 months in BU patients (p = 0.055). The analysis of other cancer genes in BU patients identified a carrier of a pathogenic germline variant in RAD51C. Thus, BRCA sequencing alone may miss tumors potentially responsive to specific treatments (due to BRCA1 promoter methylation or mutations in other genes) while unvalidated FFPE approaches may yield false-positive results.

5.
Dig Dis ; 40(4): 517-525, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34515093

RESUMO

BACKGROUND: Endoscopic surveillance in patients with Lynch syndrome (LS) is crucial due to a genetically based high risk of colorectal cancer (CRC). We aimed to compare the adenoma detection rate (ADR) between high-resolution white light endoscopy (WLE) alone and WLE plus dye chromoendoscopy (CE) in a cohort of LS patients. METHODS: In a context of real-world data, we retrospectively enrolled 50 LS patients who had non-randomly undergone WLE versus CE surveillance examinations from 2007 to 2019. The 2 groups were compared at baseline (BL) in terms of the rate of patients with lesions and the number of lesions, and at follow-up (FU), to evaluate a possible enhanced detection rate. Longitudinal analysis of the effect of the endoscopy type on the main outcomes was performed by generalized linear mixed models. RESULTS: Forty-two patients had undergone at least one diagnostic colonoscopy. At BL and at FU analysis, we found no significant differences in detection rates and clinical-pathological features between WLE and CE groups. At the longitudinal analysis, an increase in the endoscopy rank (i.e., the position of each colonoscopy for all the colonoscopies that a patient had undergone) was associated with an increase in polyp detection rate (p = 0.006) and ADR (p = 0.005), while a trend toward significance (p = 0.069) was found for endoscopy type (CE vs. WLE) in the detection of serrated lesions. CONCLUSIONS: CE is not superior to high-resolution WLE in increasing the ADR. Even under standard WLE, an active and careful endoscopic surveillance of LS patients can prevent CRC.


Assuntos
Adenoma , Neoplasias Colorretais Hereditárias sem Polipose , Neoplasias Colorretais , Adenoma/diagnóstico , Adenoma/patologia , Colonoscopia , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/patologia , Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Neoplasias Colorretais Hereditárias sem Polipose/genética , Neoplasias Colorretais Hereditárias sem Polipose/patologia , Humanos , Estudos Retrospectivos
6.
Front Med (Lausanne) ; 8: 688105, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34386506

RESUMO

Germline PTEN pathogenic variants cause a spectrum of disorders collectively labeled PTEN Hamartoma Tumor Syndrome (PHTS) and featured by hamartomas, developmental anomalies and increased cancer risk. Studies on experimental models provided evidence that PTEN is a "haploinsufficient" tumor-suppressor gene, however, mechanisms involved in the pathogenesis of clinical manifestations in PHTS patients remain elusive. Beyond analyzing clinical and molecular features of a series of 20 Italian PHTS patients, we performed molecular investigations to explore the mechanisms involved in the pathogenesis of PTEN-associated manifestations, with special focus on mucocutaneous manifestations. Typical mucocutaneous features were present in all patients assessed, confirming that these are the most important clue to the diagnosis. The most frequent were papules located in the trunk or extremities (73.7%), oral mucosa papules (68.4%), acral/palmoplantar keratosis and facial papules (both 57.9%), according with literature data. Molecular analyses on one trichilemmoma suggested that the wild-type PTEN allele was retained and expressed, reinforcing the evidence that PTEN does not require a second somatic hit to initiate pathogenic processes. Unexpectedly, one patient also displayed a cutaneous phenotype consistent with atypical mole/melanoma syndrome; no variants were detected in known melanoma genes, but Whole Exome Sequencing showed the rare truncating variant c.495G>A in the CDH13 gene that might have cooperated with PTEN-haploinsufficiency to generate such phenotype. Our findings confirm the reproducibility of known PHTS manifestations in real-world practice, highlighting the role of mucocutaneous manifestations in facilitating prompt diagnosis of the syndrome, and provide some insights into the pathogenic process induced by PTEN alterations, which may contribute to its understanding.

7.
J Popul Econ ; 34(4): 1189-1217, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34177122

RESUMO

Estimates of the real death toll of the COVID-19 pandemic have proven to be problematic in many countries, Italy being no exception. Mortality estimates at the local level are even more uncertain as they require stringent conditions, such as granularity and accuracy of the data at hand, which are rarely met. The "official" approach adopted by public institutions to estimate the "excess mortality" during the pandemic draws on a comparison between observed all-cause mortality data for 2020 and averages of mortality figures in the past years for the same period. In this paper, we apply the recently developed machine learning control method to build a more realistic counterfactual scenario of mortality in the absence of COVID-19. We demonstrate that supervised machine learning techniques outperform the official method by substantially improving the prediction accuracy of the local mortality in "ordinary" years, especially in small- and medium-sized municipalities. We then apply the best-performing algorithms to derive estimates of local excess mortality for the period between February and September 2020. Such estimates allow us to provide insights about the demographic evolution of the first wave of the pandemic throughout the country. To help improve diagnostic and monitoring efforts, our dataset is freely available to the research community. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00148-021-00857-y.

8.
Pathol Res Pract ; 218: 153339, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33482532

RESUMO

Cowden Syndrome (CS) is an autosomal dominant disorder characterized by hamartomatous growth in several organs and by an increased risk of malignancies, which makes its recognition essential to undertake risk reduction measures. Although the involvement of gastrointestinal tract is extremely common, awareness of this entity among gastroenterologists appears limited. We report on two unrelated patients: a 46-year-old male and a 38-year-old woman, who were referred to the Genetic Clinic because of the endoscopic finding of multiple colorectal polyps. Despite both displayed striking clinical (and, in the first case, familial) manifestations of Cowden Syndrome (PTEN Hamartoma Tumor Syndrome-PHTS), they had not been recognized before. Diagnosis of PHTS was confirmed by the detection of causative PTEN variants. Pathological examination of the polyps showed multiple histology types: hyperplastic, juvenile, serrated and lymphoid. Hyperplastic polyps analyzed from both patients failed to show BRAF V600E and KRAS codon 12/13 mutations, which provides evidence against their potential to evolve to colorectal cancer through the serrated pathway. We then reviewed the literature on gastrointestinal polyps detected in patients with Cowden Syndrome, in order to provide a comprehensive scenario of presentations: among a total of 568 patients reported in the literature, 91.7 % presented with colon polyps, with 63.0 % having two or more different histological types of polyps; besides, 58.5 % had extra-colonic polyps (located either in stomach and/or in small intestine). Finding multiple polyps with mixed and/or unusual histology should alert gastroenterologists and pathologists about the possible diagnosis of Cowden Syndrome and prompt the search for other manifestations of this condition in the patient.


Assuntos
Pólipos do Colo/diagnóstico , Neoplasias Colorretais/diagnóstico , Síndrome do Hamartoma Múltiplo/diagnóstico , Polipose Intestinal/diagnóstico , Adulto , Biomarcadores Tumorais/genética , Pólipos do Colo/genética , Pólipos do Colo/patologia , Pólipos do Colo/cirurgia , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Neoplasias Colorretais/cirurgia , Feminino , Predisposição Genética para Doença , Síndrome do Hamartoma Múltiplo/genética , Síndrome do Hamartoma Múltiplo/patologia , Síndrome do Hamartoma Múltiplo/cirurgia , Humanos , Polipose Intestinal/genética , Polipose Intestinal/patologia , Polipose Intestinal/cirurgia , Masculino , Pessoa de Meia-Idade , Mutação , PTEN Fosfo-Hidrolase/genética , Fenótipo
9.
Ital J Dermatol Venerol ; 156(5): 599-605, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-32221274

RESUMO

BACKGROUND: The incidence of cutaneous melanoma (cM) has increased in the last decades. Germline mutations in the high-penetrance melanoma susceptibility gene CDKN2A (Cyclin-dependent kinase inhibitor 2A) are associated with a younger age at diagnosis and an increased risk to develop pancreatic cancer. METHODS: We retrospectively analyzed the data of patients with prior diagnosis of cM referring to our service from January 2005 to May 2017. The aim was to investigate the rate of multiple cMs (MPM), assessing their clinical/pathological features. Moreover, the genetic tests of patients who had undergone CDKN2A/CDKN2B, CDK4 and MITF screening were evaluated. RESULTS: One hundred fifteen patients (9.26%) were diagnosed with MPMs: 70 males (60.87%) and 45 women (39.13%). 75 patients (43 males and 32 females) underwent genetic screening for germline mutations. The screening revealed that 4/75 patients (5.33%) were carriers of the non-synonymous missense variation c.442G>A (p.Ala148Thr) in CDKN2A exon 2 in heterozygosis, 3 of whom had at least one in-situ melanoma. In 1 patient (1.33%) we detected the variation c.249C>A, p.His83Gln in CDKN2A exon 2 in heterozygosis and in 1 patient (1.33%) the mutation c.952G>A (p.Glu318Lys) in MITF gene was found. CONCLUSIONS: This study confirms the need for a full body skin examination and a prolonged surveillance in patients affected by cM, as MPMs were detected in up to 10% of total cases in our series and synchronous lesions in 1/5. Moreover, it reflects the great variability of cM high-susceptibility genes mutational status within the Italian territory. Patients carrying c.952G>A (p.Glu318Lys) MITF mutation have a higher risk to develop a nodular cM.


Assuntos
Inibidor p16 de Quinase Dependente de Ciclina , Melanoma , Fator de Transcrição Associado à Microftalmia , Neoplasias Primárias Múltiplas , Neoplasias Cutâneas , Quinase 4 Dependente de Ciclina/genética , Inibidor p16 de Quinase Dependente de Ciclina/genética , Feminino , Humanos , Itália/epidemiologia , Masculino , Melanoma/genética , Fator de Transcrição Associado à Microftalmia/genética , Neoplasias Primárias Múltiplas/genética , Estudos Retrospectivos , Neoplasias Cutâneas/genética
10.
J Genet Couns ; 30(3): 665-675, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33142017

RESUMO

Exome/genome sequencing (ES/GS) is increasingly becoming routine in clinical genetic diagnosis, yet issues regarding how to disclose and manage secondary findings (SFs) remain to be addressed, and limited evidence is available on patients' preferences. We carried out semi-structured interviews with 307 individuals undergoing clinical genetic testing to explore their preferences for return of SFs in the hypothetical scenario that their test would be performed using ES/GS. Participants were 254 females (82.7%) and 53 males (17.3%), aged 18-86 years; 73.9% (81.1% of those with lower education levels) reported no prior knowledge of ES/GS. Prior knowledge of ES/GS was more common among patients tested for Mendelian conditions (34.5%), compared to those undergoing cancer genetic testing (22.3%) or carrier screening (7.4%). Despite this reported lack of knowledge, most participants (213, 69.6%) stated they would prefer to be informed of all possible results. Reasons in favor of disclosure included wanting to be aware of any risks (168; 83.6%) and to help relatives (23; 11.4%), but also hope that preventive measures might become available in the future (10, 5%). Conversely, potential negative impact on quality of life was the commonest motivation against disclosure. Among 179 participants seen for cancer genetic counseling who were interviewed again after test disclosure, 81.9% had not heard about ES/GS in the meantime; however, the proportion of participants opting for disclosure of any variants was lower (116; 64.8%), with 36 (20.1%) changing opinion compared to the first interview. Based on these findings, we conclude that genetic counseling for ES/GS should involve enhanced education and decision-making support to enable informed consent to SFs disclosure.


Assuntos
Exoma , Qualidade de Vida , Feminino , Testes Genéticos , Humanos , Itália , Masculino , Sequenciamento do Exoma
11.
Front Genet ; 9: 378, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30254663

RESUMO

Background: Detection of variants of uncertain significance (VUSs) in BRCA1 and BRCA2 genes poses relevant challenges for counseling and managing patients. VUS carriers should be managed similarly to probands with no BRCA1/2 variants detected, and predictive genetic testing in relatives is discouraged. However, miscomprehension of VUSs is common and can lead to inaccurate risk perception and biased decisions about prophylactic surgery. Therefore, efforts are needed to improve VUS evaluation and communication at an individual level. Aims: We aimed at investigating whether cosegregation analysis, integrated with a careful review of available functional data and in silico predictions, may improve VUSs interpretation and counseling in individual families. Methods: Patients with Breast Cancer (BC) and/or Ovarian Cancer (OC) fulfilling established criteria were offered genetic counseling and BRCA1/2 testing; VUSs identified in index cases were checked in other relatives affected by BC/OC whenever possible. As an alternative, if BC/OC clustered only in one branch of the family, the parental origin of the VUS was investigated. Public prediction tools and databases were used to collect additional information on the variants analyzed. Results: Out of 1045 patients undergoing BRCA1/2 testing in the period October 2011-April 2018, 66 (6.3%) carried class 3 VUSs. Cosegregation analysis was performed for 13 VUSs in 11 kindreds. Seven VUSs (53.8%) did not cosegregate with breast/ovarian cancer in the family, which provided evidence against their role in cancer clustering in those families. Among the 6 cosegregating VUSs, for two (BRCA1 c.5152+2T>G and BRCA2 c.7975A>G) additional evidence exists from databases and in silico tools supporting their pathogenicity, which reinforces the hypothesis they may have had a predisposing effect in respective families. For the remaining four VUSs (31%), cosegregation analysis failed to provide relevant information. Conclusion: Our findings suggest that cosegregation analysis in a clinical context may be helpful to improve test result interpretation in the specific family and, therefore, should be offered whenever possible. Besides, obtaining and sharing cosegregation data helps gathering evidence that may eventually contribute to VUS classification.

12.
Mol Cancer Res ; 16(12): 1965-1976, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30072583

RESUMO

Adenomatous Polyposis Coli (APC) gene mutations are responsible for the onset of familial adenomatous polyposis (FAP) and sporadic colorectal cancer and have been associated with miRNAs dysregulation. The capacity of miR-155, a cancer-related miRNA, to target components of the WNT/ß-CATENIN pathway suggests that APC gene mutations, controlling miRNAs expression, may critically regulate WNT/ß-CATENIN signaling. To this end, APC gene target sequencing was performed on colonic adenomatous polyps and paired normal mucosa clinical specimens from FAP patients (n = 9) to elucidate the role of miR-155-5p in APC-mutant setting. The expression of selected miRNAs and WNT/ß-CATENIN signaling components was characterized in FAP patients and non-FAP control subjects (n = 5). miR-155-5p expression and functional effects on WNT cascade, cell survival, growth, and apoptosis were investigated in different colorectal cancer cell lines. A somatic second hit in the APC gene was found in adenomatous polyps from 6 of 9 FAP patients. Heterozygous APC gene mutations in FAP patients were associated with altered expression of candidate miRNAs and increased levels of AXIN1 and AXIN2 mRNAs. miR-155-5p was downregulated in FAP patients and in the APC and ß-CATENIN-mutant colorectal cancer cell lines, and critically regulates WNT/ß-CATENIN cascade by targeting both AXIN1 and TCF4. Importantly, miR-155-5p may sustain long-term WNT/ß-CATENIN activation in colorectal cancer cells upon WNT3A stimulation. IMPLICATIONS: This study supports a key role of miR-155-5p in modulating WNT/ß-CATENIN signaling in colorectal cancer and unravels a new mechanism for AXIN1 regulation which represents a potential therapeutic target in specific tumor subtypes.


Assuntos
Proteína da Polipose Adenomatosa do Colo/genética , Polipose Adenomatosa do Colo/genética , Proteína Axina/genética , Regulação para Baixo , MicroRNAs/genética , Proteína 2 Semelhante ao Fator 7 de Transcrição/genética , Células CACO-2 , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica , Células HCT116 , Humanos , Masculino , Mutação , Análise de Sequência de RNA/métodos , Via de Sinalização Wnt
13.
Eur J Hum Genet ; 26(3): 387-395, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29367705

RESUMO

Germline variants in the APC gene cause familial adenomatous polyposis. Inherited variants in MutYH, POLE, POLD1, NTHL1, and MSH3 genes and somatic APC mosaicism have been reported as alternative causes of polyposis. However, ~30-50% of cases of polyposis remain genetically unsolved. Thus, the aim of this study was to investigate the genetic causes of unexplained adenomatous polyposis. Eight sporadic cases with >20 adenomatous polyps by 35 years of age or >50 adenomatous polyps by 55 years of age, and no causative germline variants in APC and/or MutYH, were enrolled from a cohort of 56 subjects with adenomatous colorectal polyposis. APC gene mosaicism was investigated on DNA from colonic adenomas by Sanger sequencing or Whole Exome Sequencing (WES). Mosaicism extension to other tissues (peripheral blood, saliva, hair follicles) was evaluated using Sanger sequencing and/or digital PCR. APC second hit was investigated in adenomas from mosaic patients. WES was performed on DNA from peripheral blood to identify additional polyposis candidate variants. We identified APC mosaicism in 50% of patients. In three cases mosaicism was restricted to the colon, while in one it also extended to the duodenum and saliva. One patient without APC mosaicism, carrying an APC in-frame deletion of uncertain significance, was found to harbor rare germline variants in OGG1, POLQ, and EXO1 genes. In conclusion, our restrictive selection criteria improved the detection of mosaic APC patients. In addition, we showed for the first time that an oligogenic inheritance of rare variants might have a cooperative role in sporadic colorectal polyposis onset.


Assuntos
Polipose Adenomatosa do Colo/genética , Genes APC , Mosaicismo , Herança Multifatorial , Polipose Adenomatosa do Colo/patologia , Adulto , DNA Glicosilases/genética , Enzimas Reparadoras do DNA/genética , DNA Polimerase Dirigida por DNA/genética , Exodesoxirribonucleases/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , DNA Polimerase teta
14.
Oncotarget ; 8(14): 22640-22648, 2017 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-28186987

RESUMO

We have investigated the clinical significance of the BRCA1 variant p.His1673del in 14 families from the Emilia-Romagna region of Italy, including 20 breast and 23 ovarian cancer cases; four families displayed site-specific ovarian cancer.The variant, absent in human variation databases, has been reported three times in BRCA1 specific databases; all probands shared the same rare haplotype at the BRCA1 locus, consistent with a common ancestor.The multifactorial likelihood method by Goldgar, used to estimate the probability of the variant being causative, gave a ratio of 2,263,474:1 in favor of causality. Moreover, in silico modeling suggested that His1673-lacking BRCA1 protein may have a decreased ability to bind BARD1 and other related proteins. All six ovarian carcinomas and two out of four breast carcinomas available showed a loss of the BRCA1 wild-type allele, which in three out of four ovarian carcinomas analyzed by FISH was associated with duplication of the chromosome 17 containing the variant. Although the pathogenicity of the allele is strongly supported by the multifactorial ratio,we cannot exclude that p.His1673del is not itself deleterious, but is linked to another undetected mutation on the same ancestral allele.


Assuntos
Proteína BRCA1/genética , Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Neoplasias Ovarianas/genética , Deleção de Sequência/genética , Adulto , Idoso , Neoplasias da Mama/patologia , Feminino , Predisposição Genética para Doença , Testes Genéticos , Haplótipos/genética , Humanos , Perda de Heterozigosidade , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Ovarianas/patologia , Linhagem , Fenótipo , Prognóstico
15.
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
17.
Endocrinology ; 151(11): 5255-66, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20881252

RESUMO

The small ubiquitin-like modifier-conjugating enzyme UBC9, involved in protein modification through covalent attachment of small ubiquitin-like modifier and other less defined mechanisms, has emerged as a key regulator of cell proliferation and differentiation. To explore the role of UBC9 in adipocyte differentiation, the UBC9 protein levels were examined in differentiating 3T3-L1 cells. UBC9 mRNA and protein levels were increased 2.5-fold at d 2 and then gradually declined to basal levels at d 8 of differentiation. In addition, UBC9 was expressed predominantly in the nucleus of preadipocytes but shifted to cytoplasmic compartments after d 4, after induction of differentiation. UBC9 knockdown was then achieved in differentiating 3T3-L1 preadipocytes using a specific small interfering RNA. Oil-Red-O staining demonstrated accumulation of large triglyceride droplets in approximately 90% of control cells, whereas lipid droplets were smaller and evident in only 30% of cells treated with the UBC9-specific small interfering RNA. CCAAT/enhancer-binding protein (C/EBP)-δ, peroxisome proliferator-activated receptor-γ, and C/EBPα mRNA levels were increased severalfold 2-6 d after induction of differentiation in control cells, whereas the expression of these transcription factors was significantly lower in the presence of UBC9 gene silencing. Adenovirus-mediated overexpression of a catalytically inactive mutant UBC9 protein in 3T3-L1 cells resulted in no changes in expression of adipogenic transcription factors and conversion to mature adipocytes as compared with control. In conclusion, UBC9 appears to play an important role in adipogenesis. The temporal profile of UBC9 induction and its ability to affect C/EBPδ mRNA induction support a role for this protein during early adipogenesis.


Assuntos
Adipócitos/metabolismo , Adipogenia/fisiologia , Enzimas de Conjugação de Ubiquitina/metabolismo , Células 3T3-L1 , Adipócitos/citologia , Análise de Variância , Animais , Western Blotting , Proteína alfa Estimuladora de Ligação a CCAAT/genética , Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Núcleo Celular/genética , Núcleo Celular/metabolismo , Imunofluorescência , Camundongos , PPAR gama/genética , PPAR gama/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Enzimas de Conjugação de Ubiquitina/genética
18.
Mov Disord ; 25(9): 1269-73, 2010 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-20629122

RESUMO

SCA12 is an autosomal dominant cerebellar ataxia characterized by onset in the fourth decade of life with action tremor of arms and head, mild ataxia, dysmetria, and hyperreflexia. The disease is caused by an expansion of >or=51 CAGs in the 5' region of the brain- specific phosphatase 2 regulatory subunit B-beta isoform (PPP2R2B) gene. SCA12 is very rare, except for a single ethnic group in India. We screened 159 Italian ataxic patients for SCA12 and identified two families that segregated an expanded allele of 57 to 58 CAGs, sharing a common haplotype. The age at onset, phenotype, and variability of symptoms were compatible with known cases. In one family, the disease was apparently sporadic due to possible incomplete penetrance and/or late age at onset. Our data indicate that SCA12 is also present in Italian patients, and its genetic testing should be applied to both sporadic and familial ataxias.


Assuntos
Ataxia/fisiopatologia , Proteínas do Tecido Nervoso/genética , Proteína Fosfatase 2/genética , Ataxias Espinocerebelares/diagnóstico , Expansão das Repetições de Trinucleotídeos/genética , Adolescente , Adulto , Idoso , Saúde da Família , Feminino , Humanos , Itália , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons/métodos , Prótons , Estudos Retrospectivos , Ataxias Espinocerebelares/genética , Adulto Jovem
19.
Endocrinology ; 149(3): 1302-13, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18079194

RESUMO

IGF-I regulates bone acquisition and maintenance, even though the cellular targets and signaling pathways responsible for its action in human bone cells are poorly understood. Whether abnormalities in IGF-I action and signaling occur in human osteoblasts under conditions of net bone loss has not been determined. Herein we carried out a comparative analysis of IGF-I signaling in primary cultures of human osteoblasts from osteoporotic and control donors. In comparison with control cells, osteoporotic osteoblasts showed increased tyrosine phosphorylation of the IGF-I receptor in the basal state and blunted stimulation of receptor phosphorylation by IGF-I. Augmentation of basal IGF-I receptor phosphorylation was associated with coordinate increases in basal tyrosine phosphorylation of insulin receptor substrate (IRS)-2 and activation of Erk, which were also minimally responsive to IGF-I stimulation. By contrast, phosphorylation levels of IRS-1, Akt, and glycogen synthase kinase-3 were similar in the basal state in control and osteoporotic osteoblasts and showed marked increases after IGF-I stimulation in both cell populations, even though these responses were significantly lower in the osteoporotic osteoblasts. The IGF-I signaling abnormalities in osteoporotic osteoblasts were associated with reduced DNA synthesis both under basal conditions and after stimulation with IGF-I. Interestingly, treatment of the osteoporotic osteoblasts with the MAPK kinase inhibitor PD098059 reduced the elevated levels of Erk phosphorylation and increased basal DNA synthesis. Collectively, our data show that altered osteoblast proliferation in human osteoporosis may result from dysregulation of IGF-I receptor signaling, including constitutive activation of the IRS-2/Erk signaling pathway, which becomes unresponsive to IGF-I, and defective induction of the IRS-1/Akt signaling pathway.


Assuntos
Proliferação de Células/efeitos dos fármacos , Fator de Crescimento Insulin-Like I/fisiologia , Osteoblastos/patologia , Osteoporose/fisiopatologia , Transdução de Sinais/fisiologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adulto , Idoso , Estudos de Casos e Controles , Células Cultivadas , Feminino , Quinase 3 da Glicogênio Sintase/metabolismo , Humanos , Proteínas Substratos do Receptor de Insulina , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Pessoa de Meia-Idade , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Osteoporose/metabolismo , Fosfoproteínas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor IGF Tipo 1/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...