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1.
Medicine (Baltimore) ; 99(8): e19281, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32080141

RESUMO

BACKGROUND: The aim of this meta-analysis was to assess the clinicopathological features and to confirm prognostic value of POLE exonuclease domain mutations (EDM) in endometrial carcinoma patients. METHODS: The PubMed, Web of Science, the data of China National Knowledge Infrastructure, and Wan fang Medical Network were systematically searched for relevant articles without a cut-off date. The keywords for the search were "endometrial cancer," "endometrial carcinoma," "EC," "POLE mutations," "POLE exonuclease domain mutations," "POLE-mutant," "clinical characteristics" "prognostic." Pooled hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated by using Review manager 5.3 and Stata 14.0 statistical software. RESULTS: Six cohort studies assessing 179 EC patients with POLE EDMs were included. The results indicated a favorable progression-free survival in POLE-mutant patients (HR = 0.32; 95% CI: = [0.09-1.18]). Furthermore, the overall survival was great in patients with POLE-mutant (HR = 0.68; 95% CI = [0.41-1.13]). It was shown that a significantly higher incidence of POLE mutations with Federation of International of Gynecologists and Obstetricians (FIGO) I group compared to FIGO II-IV group (pooled ORs: 0.34, 95% CI: [0.12-0.94], P = .04), POLE-mutant EC was not significantly associated with histology (OR = 0.56,95% CI: 0.29-1.23), tumor grade (OR = 1.22,95% CI:0.85-1.74), lymph-vascular space invasion (OR = 0.40,95% 0.06-2.42), depth of myometrial invasion (OR = 0.70,95% CI: 0.41-1.18), lymph node status (OR = 0.41, 95% 0.04-4.50), and European Society for Medical Oncology risk groups (OR = 0.68,95% CI: 0.37-1.26). CONCLUSION: This meta-analysis has confirmed POLE EDMs may serve as a predictive biomarker of favorable prognosis. Further studies are needed to explore the appropriate clinical utility of POLE EDMs in EC.


Assuntos
DNA Polimerase II/genética , Neoplasias do Endométrio/genética , Neoplasias do Endométrio/mortalidade , Mutação , Proteínas de Ligação a Poli-ADP-Ribose/genética , Biomarcadores Tumorais/genética , Neoplasias do Endométrio/patologia , Feminino , Humanos , Linfonodos/patologia , Miométrio/patologia , Invasividade Neoplásica , Prognóstico , Intervalo Livre de Progressão
2.
PLoS Genet ; 16(2): e1008572, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32012149

RESUMO

Cancer genomes with mutations in the exonuclease domain of Polymerase Epsilon (POLE) present with an extraordinarily high somatic mutation burden. In vitro studies have shown that distinct POLE mutants exhibit different polymerase activity. Yet, genome-wide mutation patterns and driver mutation formation arising from different POLE mutants remains unclear. Here, we curated somatic mutation calls from 7,345 colorectal cancer samples from published studies and publicly available databases. These include 44 POLE mutant samples including 9 with whole genome sequencing data available. The POLE mutant samples were categorized based on the specific POLE mutation present. Mutation spectrum, associations of somatic mutations with epigenomics features and co-occurrence with specific driver mutations were examined across different POLE mutants. We found that different POLE mutants exhibit distinct mutation spectrum with significantly higher relative frequency of C>T mutations in POLE V411L mutants. Our analysis showed that this increase frequency in C>T mutations is not dependent on DNA methylation and not associated with other genomic features and is thus specifically due to DNA sequence context alone. Notably, we found strong association of the TP53 R213* mutation specifically with POLE P286R mutants. This truncation mutation occurs within the TT[C>T]GA context. For C>T mutations, this sequence context is significantly more likely to be mutated in POLE P286R mutants compared with other POLE exonuclease domain mutants. This study refines our understanding of DNA polymerase fidelity and underscores genome-wide mutation spectrum and specific cancer driver mutation formation observed in POLE mutant cancers.


Assuntos
Carcinogênese/genética , Neoplasias Colorretais/genética , DNA Polimerase II/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Domínios Proteicos/genética , Proteína Supressora de Tumor p53/genética , Ilhas de CpG/genética , Citosina/metabolismo , Metilação de DNA/genética , Análise Mutacional de DNA/estatística & dados numéricos , DNA Polimerase II/genética , Bases de Dados Genéticas/estatística & dados numéricos , Conjuntos de Dados como Assunto , Epigênese Genética , Humanos , Mutação , Proteínas de Ligação a Poli-ADP-Ribose/genética , Sequenciamento Completo do Genoma/estatística & dados numéricos
3.
Gynecol Oncol ; 156(1): 194-202, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31757464

RESUMO

OBJECTIVES: Assess outcomes of a clinical cohort of patients with endometrioid endometrial cancer (EEC) harboring somatic POLE exonuclease domain mutations (EDMs). METHODS: Patients were consented to a protocol of tumor-normal massively parallel sequencing of 410-468 cancer related genes. EECs subjected to sequencing from 2014 to 2018 were reviewed. Tumors with somatic POLE EDMs were identified. EECs were assessed for microsatellite instability (MSI) using MSIsensor and immunohistochemical analysis for mismatch repair (MMR) proteins. RESULTS: Of the 451 EECs sequenced, 23 had a POLE EDM (5%): 20 primary and 3 recurrent tumors sequenced. Nineteen cases (83%) were stage I/II and 4 (17%) were stages III/IV. Thirteen EECs (57%) were of FIGO grades 1/2, 10 (43%) grade 3. All patients were treated with surgery and 17 (89%) received adjuvant therapy. Five (22%) demonstrated loss of DNA MMR protein expression, none were due to Lynch syndrome. MSIsensor scores were conclusive for 21 samples: 19 were microsatellite stable and 2 MSI-high. After median follow-up of 30 months, 4/23 (17%) developed recurrences: 3 with initial grade 3 stage I and 1 with grade 1 stage III disease. One patient with grade 2 stage IV EEC had progressive disease after treatment. CONCLUSIONS: Patients with POLE EDM EEC have been shown to have a favorable prognosis. In this real-world cohort of patients, de novo metastatic disease and recurrences in initially uterine-confined cases were observed. Further research is warranted before incorporating the presence of POLE EDM into decision-making regarding adjuvant therapy.


Assuntos
Carcinoma Endometrioide/genética , DNA Polimerase II/genética , Neoplasias do Endométrio/genética , Proteínas de Ligação a Poli-ADP-Ribose/genética , Adulto , Idoso , Carcinoma Endometrioide/enzimologia , Carcinoma Endometrioide/patologia , Carcinoma Endometrioide/terapia , Estudos de Coortes , Reparo de Erro de Pareamento de DNA , DNA Polimerase II/metabolismo , Neoplasias do Endométrio/enzimologia , Neoplasias do Endométrio/patologia , Neoplasias do Endométrio/terapia , Feminino , Humanos , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Mutação , Gradação de Tumores , Metástase Neoplásica , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Prognóstico , Estudos Prospectivos
4.
BMC Med Genet ; 20(1): 202, 2019 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-31864301

RESUMO

BACKGROUND: The morbidity and mortality of endometrial tumors, a common type of malignant cancer in women, have increased in recent years. POLE encodes the DNA polymerase ε, which is responsible for the leading strand DNA replication. Somatic mutations of POLE have been acknowledged in numerous cancers, resulting in the accumulation of DNA errors, leading to ultra-mutated tumors. Mutations in the exonuclease domain of POLE have been reported to improve progression-free survival in endometrial cancer. However, the potential relationship and underlying mechanism between POLE mutations and the prognosis of endometrial cancer patients remains unclear. METHODS: The whole exome sequencing data, RNA sequencing data, and clinical information were obtained from the TCGA database and employed for the analyses in this study. The detailed mutational information was analyzed using whole exome sequencing data and the mutated genes were shown with OncoPlot. The survival curves and cox proportional hazards regression analysis were used to accessed patient prognosis, the association of clinical characteristics and prognosis. Differentially expressed genes were analyzed by the edgeR R/Bioconductor package, then the GSEA Pre-ranked tool was used for Gene Set Enrichment Analysis (GSEA) to estimate the function of genes. Expression values were clustered using hierarchical clustering with Euclidean distance and ward linkage by the dendextend R package. RESULTS: POLE mutational status was proven to be an independent prognostic factor for endometrial cancer patients. Patients with somatic POLE mutations presented a favorable prognosis. POLE mutations regulated glycolysis and cytokine secretion, affecting cell metabolism and immune response. Autocrine motility factor (AMF)/PGI and AMFR/gp78 exhibited higher expression levels in POLE mutant patients. The comprehensive high expressions of AMFR/gp78 and low expression of POLE were associated with the favorable prognosis of endometrial cancer patients. CONCLUSIONS: This study showed the POLE mutations a vital factor in endometrial cancer patients, leading to a higher expression of AMF/PGI and AMFR/gp78. These results suggested comprehensive consideration of the POLE mutations, expression of AMF/PGI and AMFR/gp78 may provide a more feasible and effective approach for the treatment of endometrial cancer, which might improve the prognosis.


Assuntos
DNA Polimerase II/genética , Neoplasias do Endométrio/genética , Glucose-6-Fosfato Isomerase/metabolismo , Mutação , Proteínas de Ligação a Poli-ADP-Ribose/genética , Receptores do Fator Autócrino de Motilidade/metabolismo , Transdução de Sinais , Replicação do DNA/genética , Intervalo Livre de Doença , Neoplasias do Endométrio/metabolismo , Neoplasias do Endométrio/patologia , Feminino , Glucose/metabolismo , Humanos , Pessoa de Meia-Idade , Prognóstico
5.
PLoS Genet ; 15(11): e1008426, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31765372

RESUMO

DNA polymerase epsilon (Pol ε) is critical for genome duplication, but little is known about how post-translational modification regulates its function. Here we report that the Pol ε catalytic subunit Pol2 in yeast is sumoylated at a single lysine within a catalytic domain insertion uniquely possessed by Pol2 family members. We found that Pol2 sumoylation occurs specifically in S phase and is increased under conditions of replication fork blockade. Analyses of the genetic requirements of this modification indicate that Pol2 sumoylation is associated with replication fork progression and dependent on the Smc5/6 SUMO ligase known to promote DNA synthesis. Consistently, the pol2 sumoylation mutant phenotype suggests impaired replication progression and increased levels of gross chromosomal rearrangements. Our findings thus indicate a direct role for SUMO in Pol2-mediated DNA synthesis and a molecular basis for Smc5/6-mediated regulation of genome stability.


Assuntos
Proteínas de Ciclo Celular/genética , DNA Polimerase II/genética , DNA/biossíntese , Proteínas de Saccharomyces cerevisiae/genética , Sumoilação/genética , Domínio Catalítico/genética , DNA/genética , Replicação do DNA/genética , Instabilidade Genômica/genética , Lisina/genética , Complexos Multiproteicos/genética , Mutação/genética , Fase S/genética , Saccharomyces cerevisiae/genética , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/genética , Telômero/genética
6.
PLoS Genet ; 15(11): e1008427, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31765407

RESUMO

Replication fork stalling and accumulation of single-stranded DNA trigger the S phase checkpoint, a signalling cascade that, in budding yeast, leads to the activation of the Rad53 kinase. Rad53 is essential in maintaining cell viability, but its targets of regulation are still partially unknown. Here we show that Rad53 drives the hyper-SUMOylation of Pol2, the catalytic subunit of DNA polymerase ε, principally following replication forks stalling induced by nucleotide depletion. Pol2 is the main target of SUMOylation within the replisome and its modification requires the SUMO-ligase Mms21, a subunit of the Smc5/6 complex. Moreover, the Smc5/6 complex co-purifies with Pol ε, independently of other replisome components. Finally, we map Pol2 SUMOylation to a single site within the N-terminal catalytic domain and identify a SUMO-interacting motif at the C-terminus of Pol2. These data suggest that the S phase checkpoint regulate Pol ε during replication stress through Pol2 SUMOylation and SUMO-binding ability.


Assuntos
Proteínas de Ciclo Celular/genética , Quinase do Ponto de Checagem 2/genética , DNA Polimerase II/genética , DNA/biossíntese , Proteína SUMO-1/genética , Proteínas de Saccharomyces cerevisiae/genética , Sumoilação/genética , Domínio Catalítico/genética , DNA/genética , Replicação do DNA/genética , Complexos Multiproteicos/genética , Ligação Proteica , Fase S/genética , Saccharomyces cerevisiae/genética , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/genética
7.
Mol Cell ; 76(3): 371-381.e4, 2019 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-31495565

RESUMO

Break-induced replication (BIR) is a pathway of homology-directed repair that repairs one-ended DNA breaks, such as those formed at broken replication forks or uncapped telomeres. In contrast to conventional S phase DNA synthesis, BIR proceeds by a migrating D-loop and results in conservative synthesis of the nascent strands. DNA polymerase delta (Pol δ) initiates BIR; however, it is not known whether synthesis of the invading strand switches to a different polymerase or how the complementary strand is synthesized. By using alleles of the replicative DNA polymerases that are permissive for ribonucleotide incorporation, thus generating a signature of their action in the genome that can be identified by hydrolytic end sequencing, we show that Pol δ replicates both the invading and the complementary strand during BIR. In support of this conclusion, we show that depletion of Pol δ from cells reduces BIR, whereas depletion of Pol ε has no effect.


Assuntos
Quebras de DNA , DNA Polimerase III/metabolismo , Replicação do DNA , DNA Fúngico/biossíntese , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/enzimologia , DNA Ligase Dependente de ATP/genética , DNA Ligase Dependente de ATP/metabolismo , DNA Polimerase I/genética , DNA Polimerase I/metabolismo , DNA Polimerase II/genética , DNA Polimerase II/metabolismo , DNA Polimerase III/genética , DNA Fúngico/genética , Células HEK293 , Células HeLa , Humanos , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética
8.
J Hum Genet ; 64(8): 729-740, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31089268

RESUMO

Polymerase proofreading-associated polyposis (PPAP) is a disease caused by germline variations in the POLE and POLD1 genes that encode catalytic subunits of DNA polymerases. Studies of cancer genomes have identified somatic mutations in these genes, suggesting the importance of polymerase proofreading of DNA replication in suppressing tumorigenesis. Here, we identified a germline frameshift variation in the POLE gene (c.4191_4192delCT, p.Tyr1398*) in a case with multiple adenomatous polyps and three synchronous colon cancers. Interestingly, one of the colon cancers showed microsatellite instability-high (MSI-H) and another microsatellite stable. Immunohistochemical staining revealed that the MSI-H tumor cells lost the expression of MLH1 protein. Whole genome sequencing of the MSI-H tumor did not find pathogenic somatic mutations in mismatch repair genes but found frameshift mutations in the TET genes that catalyze 5-methylcytosine hydroxylation. Bisulfite sequencing of the tumor corroborated an increase in the number of hypermethylated regions including the MLH1 promoter. These data indicate that PPAP patients might develop MSI-positive tumors through epigenetic silencing of MLH1. These findings will contribute to comprehensive understanding of the molecular basis of tumors that involve deficiency of proofreading activity of DNA polymerases.


Assuntos
Neoplasias do Colo/genética , Neoplasias Colorretais Hereditárias sem Polipose/genética , Metilação de DNA , Estudos de Associação Genética , Predisposição Genética para Doença , Instabilidade de Microssatélites , Idoso , Alelos , Neoplasias do Colo/diagnóstico , Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Análise Mutacional de DNA , DNA Polimerase II/genética , DNA Polimerase II/metabolismo , Feminino , Mutação da Fase de Leitura , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Genótipo , Mutação em Linhagem Germinativa , Humanos , Imuno-Histoquímica , Masculino , Estadiamento de Neoplasias , Linhagem , Fenótipo , Proteínas de Ligação a Poli-ADP-Ribose/genética , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Proteínas Repressoras/genética , Sequenciamento Completo do Genoma
9.
Clin Exp Med ; 19(3): 393-400, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31049795

RESUMO

The colorectal cancer harbor germline, somatic or epimutations in mismatch repair genes, MUTYH or POLE gene, which lead to the hypermutated and ultramutator phenotypes with increased immune response. The mutations in POLE gene were reported to occur more frequently in early-onset colorectal cancer (EOCRC), and the patients are strong candidates for checkpoint inhibitor therapy. Here, we report mutation analysis within the endonuclease domain of the POLE gene in the cohort of patients with EOCRC in order to identify recurrent or new mutations and evaluate their association with the presence of tumor-infiltrating lymphocytes (TILs) and peritumoral lymphoid reaction. We have shown a significant association between MSI tumors and TILs (p = 0.004). Using sensitive single-tube nested PCR with subsequent Sanger sequencing, we have found in one female patient diagnosed at age 48 with rectal adenocarcinoma with mucinous elements staged pT3pN2pM1 a silent variant within the exon 9 NM_006231.3 c.849 C > T, NP_00622.2 p.Leu283 = recorded in dSNP as rs1232888774 with MAF = 0.00002. In silico prediction, result showed possible involvement into splicing; therefore, this rare variant can be involved into EOCRC pathogenesis. In the time of precise medicine, it is important to develop screening strategies also for less common conditions such as EOCRC allowing to predict tailored therapy for younger patients suffering from CRC that harbor mutations in the POLE gene.


Assuntos
Neoplasias Colorretais/genética , DNA Polimerase II/genética , Mutação , Proteínas de Ligação a Poli-ADP-Ribose/genética , Adulto , Feminino , Técnicas de Genotipagem , Humanos , Masculino , Pessoa de Meia-Idade
10.
Fam Cancer ; 18(3): 343-348, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31114938

RESUMO

A high colorectal cancer (CRC) incidence is observed in Tunisia, with a relatively high proportion of patients developing CRC before the age of 40. While this suggests a genetic susceptibility, only a few Tunisian Lynch Syndrome families have been described. In this study we aimed to identify the underlying genetic cause in 32 patients with early onset CRC and/or a positive family history. Of twenty-four patients' tumor or biopsies could be analyzed with immunohistochemical staining to detect loss of expression of one of the MMR proteins. Ten tumors showed loss of expression, of which one tumor was from a patient where a germline pathogenic MSH2 variant was detected previously with Sanger sequencing. Next generation sequencing of the MMR, POLE and POLD1 genes was performed in leukocyte and tumor DNA of the remaining nine patients, as well as in two patients with MMR-proficient tumors, but with severe family history. In six of 11 patients a germline variant was detected in MLH1 (n = 5) or MSH2 (n = 1). Two of six patients were from the same family and both were found to carry a novel in-frame MLH1 deletion, predicted to affect MLH1 function. All MLH1 variant carriers had loss of heterozygosity with retention of the variant in the tumors, while a somatic pathogenic variant was detected in the patient with the germline MSH2 variant.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/genética , Mutação em Linhagem Germinativa , Sequenciamento de Nucleotídeos em Larga Escala , Adulto , Idoso , Neoplasias Colorretais/genética , DNA Polimerase II/genética , DNA Polimerase III/genética , Saúde da Família , Feminino , Deleção de Genes , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL/genética , Proteína 2 Homóloga a MutS/genética , Linhagem , Proteínas de Ligação a Poli-ADP-Ribose/genética , Tunísia , Adulto Jovem
11.
Gynecol Oncol ; 153(3): 471-478, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30935717
12.
Future Oncol ; 15(12): 1335-1346, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30887833

RESUMO

Aim: To compare endocrine characteristics of  endometrial cancer (EC) patients based on recent molecular EC types classification. Materials & methods: A total of 234 treatment-naive EC patients as well their tumors were studied. Results: Patients with POLE mutations demonstrated tendency to lower body mass index (BMI) and higher serum estradiol. Patients with p53 overexpression were older and had higher diabetes incidence. In the without characteristic molecular profile group there was no difference in fasting serum insulin, estradiol and testosterone levels between women with BMI ≥30.0 and <30.0. The mismatch repair deficient group patients had a tendency toward later menarche compared with the without characteristic molecular profile group one. Conclusion: Studied endocrine characteristics are associated with BMI or tumor molecular-biological type that might be relevant to EC genesis, course and prognosis.


Assuntos
Índice de Massa Corporal , Sistema Endócrino/metabolismo , Neoplasias do Endométrio/metabolismo , Endométrio/patologia , Obesidade/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Reparo de Erro de Pareamento de DNA/genética , DNA Polimerase II/genética , Neoplasias do Endométrio/sangue , Neoplasias do Endométrio/genética , Neoplasias do Endométrio/patologia , Endométrio/cirurgia , Estradiol/sangue , Feminino , Humanos , Histerectomia , Insulina/sangue , Leptina/sangue , Pessoa de Meia-Idade , Mutação , Obesidade/sangue , Obesidade/genética , Proteínas de Ligação a Poli-ADP-Ribose/genética , Testosterona/sangue
13.
Gynecol Oncol ; 153(3): 487-495, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30922603

RESUMO

OBJECTIVE: Approximately 15% of endometrial carcinomas (ECs) arise in young women who may wish to avoid surgical menopause and/or preserve fertility. Our aim was to evaluate the prognostic significance of Proactive Molecular risk classifier for Endometrial Carcinoma (ProMisE) in young (<50 yo) women with EC. METHODS: ProMisE was applied to a retrospective cohort of women with ECs <50 yo at diagnosis, and associations between the four ProMisE molecular subtypes (MMR deficient (MMRd), POLE mutated (POLE), p53 wild type (p53wt), and p53 abnormal (p53abn)) and clinicopathological parameters, including outcomes, were assessed. RESULTS: Of 257 ECs, there were 48 (19%) MMRd, 34 (13%) POLE, 164 (64%) p53wt and 11 (4%) p53abn. ProMisE subtypes were associated with differences in all measured clinicopathological parameters except for presence of synchronous ovarian tumours and fertility. Age at diagnosis was youngest and BMI highest in women with p53wt ECs. MMRd and p53abn tumours were more likely to be advanced stage (III/IV), high-risk (ESMO), and receive chemotherapy. ProMisE subtypes were strongly associated with outcomes (overall, disease-specific, and progression-free survival (p < 0.0001 for all)). Advanced stage, grade, LVSI, myometrial invasion and ESMO risk groups showed associations with some but not all survival parameters. ProMisE maintained a strong association with OS and DSS on multivariable analysis. CONCLUSIONS: ProMisE molecular classification is prognostic in young women with EC, enabling early stratification and risk assignment to direct care. Further studies can assess response to therapy, fertility, and cancer-related outcomes within the framework of molecular subtype.


Assuntos
Carcinoma/classificação , DNA Polimerase II/genética , Proteínas de Ligação a DNA/metabolismo , Neoplasias do Endométrio/classificação , Endonuclease PMS2 de Reparo de Erro de Pareamento/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/genética , Proteína Supressora de Tumor p53/metabolismo , Adulto , Fatores Etários , Índice de Massa Corporal , Carcinoma/genética , Carcinoma/metabolismo , Carcinoma/secundário , Neoplasias do Endométrio/genética , Neoplasias do Endométrio/metabolismo , Neoplasias do Endométrio/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , Intervalo Livre de Progressão , Estudos Retrospectivos , Taxa de Sobrevida
14.
PLoS One ; 14(3): e0214318, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30917185

RESUMO

BACKGROUND AND PURPOSE: Individualized therapy in endometrial cancer, the most common gynaecologic cancer in the developed world, focuses on identifying specific molecular subtypes. Mutations in the exonuclease domain of the DNA polymerase epsilon (POLE) gene define one such subtype, which causes an ultra-mutated tumour phenotype. These tumours may have an improved progression-free survival and may be receptive to specific therapies. However, the clinical phenotype of these tumours is unknown. The objective of this study was to evaluate the clinical and genetic features of POLE-mutated tumours from a large cohort of women whose cases are characterized by: (1) the availability of detailed clinical and lifestyle data; (2) mutation analysis; and (3) long-term follow-up. METHODS: A total of 604 patients with endometrial cancer were included in the study. Data from a detailed questionnaire, including lifestyle and family history information, provided extensive pertinent information on the patients. Sequencing of exons 9-14 of the POLE gene was performed. Follow-up data were gathered and analysed. RESULTS: Hotspot pathogenic POLE mutations were identified in N = 38/599 patients (6.3%). Patients with a POLE-mutated tumour were significantly younger, were more often nulliparous, and had a history of smoking. POLE-mutated tumours were more frequently aneuploid. Prognosis for patients with hotspot POLE-mutated tumours was significantly better in comparison with patients with non-mutated tumours; however careful selection of pathogenic mutations is essential to the definition of this prognostically favourable group. CONCLUSIONS: This study demonstrates that POLE-mutated endometrial cancer is significantly associated with previously unknown clinicopathologic characteristics. Outcome in POLE-mutated tumours was excellent in cases with hotspot mutations. Our results suggest that prediction of excellent outcome in cases of POLE-mutated EMCA should be restricted to cases of EMCA with hotspot mutations until further data are available on the rising number of mutations with unknown significance.


Assuntos
DNA Polimerase II/genética , Neoplasias do Endométrio/genética , Mutação , Proteínas de Ligação a Poli-ADP-Ribose/genética , Análise de Sequência de DNA/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias do Endométrio/patologia , Éxons , Feminino , Humanos , Pessoa de Meia-Idade , Paridade , Fenótipo , Medicina de Precisão , Prognóstico , Fatores de Risco , Fumar/efeitos adversos , Fumar/epidemiologia , Análise de Sobrevida
15.
Gynecol Oncol ; 153(3): 517-520, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30910249

RESUMO

OBJECTIVES: Stage I, grade 1 endometrial cancers have low recurrence rates and often do not receive adjuvant therapy. We compared recurrent cases to matched non-recurrent controls to evaluate for molecular markers associated with higher risk of recurrence. METHODS: A case-control study including all cases of recurrent stage I, grade 1 endometrioid endometrial cancer at one institution in a ten-year period. Cases were matched to controls by age, BMI, weight and stage. Molecular testing and immunohistochemistry were performed on archival tumor specimens: microsatellite instability (MSI-H), mismatch repair status, POLE mutational status, and next-generation sequencing. RESULTS: 15 stage I, grade 1 endometrial cancer cases with recurrent disease and available tumor specimens were identified. CTNNB1 and MSI-H were present at significantly higher rates in cases than controls (CTNNB1 60% vs. 28%, OR 3.9, 95%CI 1.1-14.7, p = 0.04 and MSI-H 53% vs. 21%, OR 4.4, 95%CI 1.1-17.0, p = 0.03). POLE mutations were found in 0% of cases vs. 7% of controls (p = 0.54). Among specimens demonstrating microsatellite stability (MSS), 100% of cases vs. 26% of controls had CTNNB1 mutations (p < 0.001). CTNNB1 wild type tumors were MSI-H in 100% of cases vs. 19% of controls (p < 0.001). CONCLUSIONS: Compared to controls, CTNNB1 mutation is present at significantly higher rates in recurrent stage I, grade 1 endometrial cancers and is found most commonly in MSS tumors. MSI-H is also present at significantly higher rates in recurrent cases. These markers may be useful for prognostic risk stratification and adjuvant therapy decision-making in this otherwise low-risk population.


Assuntos
Carcinoma Endometrioide/genética , Neoplasias do Endométrio/genética , Recidiva Local de Neoplasia/genética , beta Catenina/genética , Adulto , Idoso , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma Endometrioide/patologia , Estudos de Casos e Controles , Classe I de Fosfatidilinositol 3-Quinases/genética , DNA Polimerase II/genética , Neoplasias do Endométrio/patologia , Feminino , Humanos , Proteínas de Membrana/genética , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Mutação , Gradação de Tumores , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , PTEN Fosfo-Hidrolase/genética , Proteínas de Ligação a Poli-ADP-Ribose/genética , Proteína Supressora de Tumor p53/genética
16.
Mol Genet Genomic Med ; 7(4): e00603, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30827058

RESUMO

BACKGROUND: Germline mutations affecting the exonuclease domains of POLE and POLD1 predispose to colorectal adenomas and carcinoma. Here, we aimed to screen the exonuclease domains to find the genetic causes of multiple colorectal polyps in unexplained cases. METHODS: Using a custom next-generation sequencing panel, we sequenced the exonuclease domains of POLE and POLD1 in 332 index patients diagnosed with multiple colorectal polyps without germline alteration in colorectal polyposis predisposing genes. RESULTS: We identified two variants of unknown significance. One germline POLD1 c.961G>A, p.(Gly321Ser) variant was found in two cases. The first patient was diagnosed with multiple polyps at age 35 and colorectal cancer (CRC) at age 37, with no known family history of CRC. The second patient was diagnosed with CRC at age 44 and cumulatively developed multiple polyps; this patient had two sisters with endometrial cancer who did not carry the variant. Furthermore, we identified a novel POLD1 c.955 T>G, p.(Cys319Gly) variant in a patient diagnosed with multiple colorectal adenomas at age 40. Co-segregation analysis showed that one sister who cumulatively developed multiple adenomas from age 34, and another sister who developed CRC at age 38 did not carry the variant. We did not identify pathogenic variants in POLE and POLD1. CONCLUSION: This study confirms the low frequency of causal variants in these genes in the predisposition for multiple colorectal polyps, and also establishes that these genes are a rare cause of the disease.


Assuntos
Pólipos do Colo/genética , Neoplasias Colorretais/genética , DNA Polimerase III/genética , DNA Polimerase II/genética , Taxa de Mutação , Proteínas de Ligação a Poli-ADP-Ribose/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Domínio Catalítico , DNA Polimerase II/química , DNA Polimerase III/química , Feminino , Mutação em Linhagem Germinativa , Humanos , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Proteínas de Ligação a Poli-ADP-Ribose/química
17.
Hum Genomics ; 13(1): 4, 2019 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-30630526

RESUMO

BACKGROUND: Germline BRCA1/2 prevalence is relatively low in sporadic triple-negative breast cancer (TNBC). We hypothesized that non-BRCA genes may also have significant germline contribution to Chinese sporadic TNBC, and the somatic mutational landscape of TNBC may vary between ethnic groups. We therefore conducted this study to investigate germline and somatic mutations in 43 cancer susceptibility genes in Chinese sporadic TNBC. PATIENTS AND METHODS: Sixty-six Chinese sporadic TNBC patients were enrolled in this study. Germline and tumor DNA of each patient were subjected to capture-based next-generation sequencing using a 43-gene panel. Standard bioinformatic analysis and variant classification were performed to identify deleterious/likely deleterious germline mutations and somatic mutations. Mutational analysis was conducted to identify significantly mutated genes. RESULTS: Deleterious/likely deleterious germline mutations were identified in 27 (27/66, 40.9%) patients. Among the 27 patients, 9 (9/66, 13.6%) were TP53 carriers, 5 (5/66, 7.6%) were MSH6 carriers, and 5 (5/66, 7.6%) were BRCA1 carriers. Somatic mutations were identified in 64 (64/66, 97.0%) patients. TP53 somatic mutations occurred in most of the patients (45/66, 68.2%) and with highest mean allele frequency (28.1%), while NF1 and POLE were detected to have the highest mutation counts. CONCLUSIONS: Our results supported our hypotheses and suggested great potentials of TP53 and MSH6 as novel candidates for TNBC predisposition genes. The high frequency of somatic NF1 and POLE mutations in this study showed possibilities for clinical benefits from androgen-blockade therapies and immunotherapies in Chinese TNBC patients. Our study indicated necessity of multi-gene testing for TNBC prevention and treatment.


Assuntos
Proteínas de Ligação a DNA/genética , Mutação em Linhagem Germinativa , Neoplasias de Mama Triplo Negativas/genética , Proteína Supressora de Tumor p53/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Grupo com Ancestrais do Continente Asiático/genética , Proteínas Mutadas de Ataxia Telangiectasia/genética , DNA Polimerase II/genética , Feminino , Humanos , Pessoa de Meia-Idade , Neurofibromina 1/genética , Proteínas de Ligação a Poli-ADP-Ribose/genética
18.
Nat Commun ; 10(1): 374, 2019 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-30670691

RESUMO

Alterations in the exonuclease domain of DNA polymerase ε (Polε) cause ultramutated tumors. Severe mutator effects of the most common variant, Polε-P286R, modeled in yeast suggested that its pathogenicity involves yet unknown mechanisms beyond simple proofreading deficiency. We show that, despite producing a catastrophic amount of replication errors in vivo, the yeast Polε-P286R analog retains partial exonuclease activity and is more accurate than exonuclease-dead Polε. The major consequence of the arginine substitution is a dramatically increased DNA polymerase activity. This is manifested as a superior ability to copy synthetic and natural templates, extend mismatched primer termini, and bypass secondary DNA structures. We discuss a model wherein the cancer-associated substitution limits access of the 3'-terminus to the exonuclease site and promotes binding at the polymerase site, thus stimulating polymerization. We propose that the ultramutator effect results from increased polymerase activity amplifying the contribution of Polε errors to the genomic mutation rate.


Assuntos
Substituição de Aminoácidos , DNA Polimerase II/genética , DNA Polimerase II/metabolismo , Neoplasias/genética , Neoplasias/metabolismo , Sequência de Aminoácidos , Arginina , Sequência de Bases , DNA/química , Dano ao DNA , Enzimas Reparadoras do DNA , Replicação do DNA , DNA Polimerase Dirigida por DNA/metabolismo , Genes Fúngicos , Humanos , Mutagênese , Mutação , Taxa de Mutação , Fenótipo , Domínios Proteicos/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética
19.
Nat Commun ; 10(1): 373, 2019 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-30670696

RESUMO

The most frequently recurring cancer-associated DNA polymerase ε (Pol ε) mutation is a P286R substitution in the exonuclease domain. While originally proposed to increase genome instability by disrupting exonucleolytic proofreading, the P286R variant was later found to be significantly more pathogenic than Pol ε proofreading deficiency per se. The mechanisms underlying its stronger impact remained unclear. Here we report the crystal structure of the yeast orthologue, Pol ε-P301R, complexed with DNA and an incoming dNTP. Structural changes in the protein are confined to the exonuclease domain, with R301 pointing towards the exonuclease site. Molecular dynamics simulations suggest that R301 interferes with DNA binding to the exonuclease site, an outcome not observed with the exonuclease-inactive Pol ε-D290A,E292A variant lacking the catalytic residues. These results reveal a distinct mechanism of exonuclease inactivation by the P301R substitution and a likely basis for its dramatically higher mutagenic and tumorigenic effects.


Assuntos
DNA Polimerase II/genética , DNA Polimerase II/metabolismo , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/metabolismo , Sequência de Aminoácidos , Carcinogênese , DNA , Reparo de Erro de Pareamento de DNA , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Exonucleases/genética , Exonucleases/metabolismo , Humanos , Simulação de Dinâmica Molecular , Mutagênese , Mutação , Neoplasias/genética , Neoplasias/metabolismo , Conformação Proteica , Domínios Proteicos/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Alinhamento de Sequência
20.
Nucleic Acids Res ; 47(8): 3986-3995, 2019 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-30698744

RESUMO

The four B-family DNA polymerases α, δ, ϵ and ζ cooperate to accurately replicate the eukaryotic nuclear genome. Here, we report that a Saccharomyces cerevisiae strain encoding the pol2-16 mutation that lacks Pol ϵ's polymerase and exonuclease activities has increased dNTP concentrations and an increased mutation rate at the CAN1 locus compared to wild type yeast. About half of this mutagenesis disappears upon deleting the REV3 gene encoding the catalytic subunit of Pol ζ. The remaining, still strong, mutator phenotype is synergistically elevated in an msh6Δ strain and has a mutation spectrum characteristic of mistakes made by Pol δ. The results support a model wherein slow-moving replication forks caused by the lack of Pol ϵ's catalytic domains result in greater involvement of mutagenic DNA synthesis by Pol ζ as well as diminished proofreading by Pol δ during replication.


Assuntos
DNA Polimerase II/genética , DNA Fúngico/genética , DNA Polimerase Dirigida por DNA/genética , Regulação Fúngica da Expressão Gênica , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Sistemas de Transporte de Aminoácidos Básicos/genética , Sistemas de Transporte de Aminoácidos Básicos/metabolismo , Domínio Catalítico , DNA Polimerase II/metabolismo , Replicação do DNA , DNA Fúngico/metabolismo , DNA Polimerase Dirigida por DNA/deficiência , Deleção de Genes , Taxa de Mutação , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo
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