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1.
Clin Gastroenterol Hepatol ; 18(2): 368-374.e1, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31220642

RESUMO

BACKGROUND & AIMS: Lynch syndrome is characterized by DNA mismatch repair (MMR) deficiency. Some patients with suspected Lynch syndrome have DNA MMR deficiencies but no detectable mutations in genes that encode MMR proteins-this is called Lynch-like syndrome (LLS). There is no consensus on management of patients with LLS. We collected data from a large series of patients with LLS to identify clinical and pathology features. METHODS: We collected data from a nationwide-registry of patients with colorectal cancer (CRC) in Spain. We identified patients whose colorectal tumors had loss of MSH2, MSH6, PMS2, or MLH1 (based on immunohistochemistry), without the mutation encoding V600E in BRAF (detected by real-time PCR), and/or no methylation at MLH1 (determined by methylation-specific multiplex ligation-dependent probe amplification), and no pathogenic mutations in MMR genes, BRAF, or EPCAM (determined by DNA sequencing). These patients were considered to have LLS. We collected data on demographic, clinical, and pathology features and family history of neoplasms. The χ2 test was used to analyze the association between qualitative variables, followed by the Fisher exact test and the Student t test or the Mann-Whitney test for quantitative variables. RESULTS: We identified 160 patients with LLS; their mean age at diagnosis of CRC was 55 years and 66 patients were female (41%). The Amsterdam I and II criteria for Lynch syndrome were fulfilled by 11% of cases and the revised Bethesda guideline criteria by 65% of cases. Of the patients with LLS, 24% were identified in universal screening. There were no proportional differences in sex, indication for colonoscopy, immunohistochemistry, pathology findings, or personal history of CRC or other Lynch syndrome-related tumors between patients who met the Amsterdam and/or Bethesda criteria for Lynch syndrome and patients identified in universal screening for Lynch syndrome, without a family history of CRC. CONCLUSIONS: Patients with LLS have homogeneous clinical, demographic, and pathology characteristics, regardless of family history of CRC.

2.
Artigo em Inglês | MEDLINE | ID: mdl-30675318

RESUMO

Background: Approximately 5 to 10% of all cancers are caused by inherited germline mutations, many of which are associated with different Hereditary Cancer Syndromes (HCS). In the context of the Program of Hereditary Cancer of the Valencia Community, individuals belonging to specific HCS and their families receive genetic counselling and genetic testing according to internationally established guidelines. The current diagnostic approach is based on sequencing a few high-risk genes related to each HCS; however, this method is time-consuming, expensive and does not achieve a confirmatory genetic diagnosis in many cases. This study aims to test the level of improvement offered by a Next Generation Sequencing (NGS) gene-panel compared to the standard approach in a diagnostic reference laboratory setting. Methods: A multi-gene NGS panel was used to test a total of 91 probands, previously classified as non-informative by analysing the high-risk genes defined in our guidelines. Results: Nineteen deleterious mutations were detected in 16% of patients, some mutations were found in already-tested high-risk genes (BRCA1, BRCA2, MSH2) and others in non-prevalent genes (RAD51D, PALB2, ATM, TP53, MUTYH, BRIP1). Conclusions: Overall, our findings reclassify several index cases into different HCS, and change the mutational status of 14 cases from non-informative to gene mutation carriers. In conclusion, we highlight the necessity of incorporating validated multi-gene NGS panels into the HCSs diagnostic routine to increase the performance of genetic diagnosis.

3.
Micromachines (Basel) ; 9(3)2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30424062

RESUMO

The use of blood samples as liquid biopsy is a label-free method for cancer diagnosis that offers benefits over traditional invasive biopsy techniques. Cell sorting by acoustic waves offers a means to separate rare cells from blood samples based on their physical properties in a label-free, contactless and biocompatible manner. Herein, we describe a flow-through separation approach that provides an efficient separation of tumor cells (TCs) from white blood cells (WBCs) in a microfluidic device, "THINUS-Chip" (Thin-Ultrasonic-Separator-Chip), actuated by ultrasounds. We introduce for the first time the concept of plate acoustic waves (PAW) applied to acoustophoresis as a new strategy. It lies in the geometrical chip design: different to other microseparators based on either bulk acoustic waves (BAW) or surface waves (SAW, SSAW and tSAW), it allows the use of polymeric materials without restrictions in the frequency of work. We demonstrate its ability to perform high-throughput isolation of TCs from WBCs, allowing a recovery rate of 84% ± 8% of TCs with a purity higher than 80% and combined viability of 85% at a flow rate of 80 µL/min (4.8 mL/h). The THINUS-Chip performs cell fractionation with low-cost manufacturing processes, opening the door to possible easy printing fabrication.

4.
Br J Cancer ; 119(8): 978-987, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30283143

RESUMO

BACKGROUND: Constitutional MLH1 epimutations are characterised by monoallelic methylation of the MLH1 promoter throughout normal tissues, accompanied by allele-specific silencing. The mechanism underlying primary MLH1 epimutations is currently unknown. The aim of this study was to perform an in-depth characterisation of constitutional MLH1 epimutations targeting the aberrantly methylated region around MLH1 and other genomic loci. METHODS: Twelve MLH1 epimutation carriers, 61 Lynch syndrome patients, and 41 healthy controls, were analysed by Infinium 450 K array. Targeted molecular techniques were used to characterise the MLH1 epimutation carriers and their inheritance pattern. RESULTS: No nucleotide or structural variants were identified in-cis on the epimutated allele in 10 carriers, in which inter-generational methylation erasure was demonstrated in two, suggesting primary type of epimutation. CNVs outside the MLH1 locus were found in two cases. EPM2AIP1-MLH1 CpG island was identified as the sole differentially methylated region in MLH1 epimutation carriers compared to controls. CONCLUSION: Primary constitutional MLH1 epimutations arise as a focal epigenetic event at the EPM2AIP1-MLH1 CpG island in the absence of cis-acting genetic variants. Further molecular characterisation is needed to elucidate the mechanistic basis of MLH1 epimutations and their heritability/reversibility.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/genética , Neoplasias Colorretais/genética , Metilação de DNA/genética , Epigênese Genética/genética , Predisposição Genética para Doença/genética , Proteína 1 Homóloga a MutL/genética , Sequência de Bases , Neoplasias Colorretais/epidemiologia , Ilhas de CpG/genética , Feminino , Haplótipos/genética , Humanos , Masculino , Mutação/genética , Regiões Promotoras Genéticas/genética , Análise de Sequência de DNA
5.
PLoS One ; 13(9): e0203051, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30188916

RESUMO

OBJECTIVE: The aim of this study was to validate a molecular classification of colorectal cancer (CRC) based on microsatellite instability (MSI), CpG island methylator phenotype (CIMP) status, BRAF, and KRAS and investigate each subtype's response to chemotherapy. DESIGN: This retrospective observational study included a population-based cohort of 878 CRC patients. We classified tumours into five different subtypes based on BRAF and KRAS mutation, CIMP status, and MSI. Patients with advanced stage II (T4N0M0) and stage III tumours received 5-fluoruracil (5-FU)-based chemotherapy or no adjuvant treatment based on clinical criteria. The main outcome was disease-free survival (DFS). RESULTS: Patients with the combination of microsatellite stable (MSS) tumours, BRAF mutation and CIMP positive exhibited the worst prognosis in univariate (log rank P<0.0001) and multivariate analyses (hazard ratio 1.75, 95% CI 1.05-2.93, P = 0.03) after adjusting for age, sex, chemotherapy, and TNM stage. Treatment with 5-FU-based regimens improved prognosis in patients with the combination of MSS tumours, KRAS mutation and CIMP negative (log rank P = 0.003) as well as in patients with MSS tumours plus BRAF and KRAS wild-type and CIMP negative (log-rank P<0.001). After adjusting for age, sex, and TNM stage in the multivariate analysis, only patients with the latter molecular combination had independently improved prognosis after adjuvant chemotherapy (hazard ratio 2.06, 95% CI 1.24-3.44, P = 0.005). CONCLUSION: We confirmed the prognostic value of stratifying CRC according to molecular subtypes using MSI, CIMP status, and somatic KRAS and BRAF mutation. Patients with traditional chromosomally unstable tumours obtained the best benefit from adjuvant 5-FU-based chemotherapy.


Assuntos
Antimetabólitos Antineoplásicos/uso terapêutico , Neoplasias Colorretais/classificação , Neoplasias Colorretais/tratamento farmacológico , Fluoruracila/uso terapêutico , Adulto , Idoso , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Ilhas de CpG , Metilação de DNA , Feminino , Humanos , Masculino , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Mutação , Estadiamento de Neoplasias , Prognóstico , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Estudos Retrospectivos
6.
Gastroenterology ; 153(1): 106-112.e2, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28400194

RESUMO

BACKGROUND & AIMS: We investigated whether patients with multiple serrated polyps, but not meeting the World Health Organization criteria for serrated polyposis syndrome, and their relatives have similar risks for colorectal cancer (CRC) as those diagnosed with serrated polyposis. METHODS: We collected data from patients with more than 10 colonic polyps, recruited in 2008-2009 from 24 hospitals in Spain for a study of causes of multiple colonic polyps. We analyzed data from 53 patients who met the criteria for serrated polyposis and 145 patients who did not meet these criteria, but who had more than 10 polyps throughout the colon, of which more than 50% were serrated. We calculated age- and sex-adjusted standardized incidence ratios (SIRs) for CRC in both groups, as well as in their first-degree relatives. RESULTS: The prevalence of CRC was similar between patients with confirmed serrated polyposis and multiple serrated polyps (odds ratio, 1.35; 95% confidence interval [CI], 0.64-2.82; P = .40). The SIR for CRC in patients with serrated polyposis (0.51; 95% CI, 0.01-2.82) did not differ significantly from the SIR for CRC in patients with multiple serrated polyps (0.74; 95% CI, 0.20-1.90; P = .70). The SIR for CRC also did not differ significantly between first-degree relatives of these groups (serrated polyposis: 3.28, 95% CI, 2.16-4.77; multiple serrated polyps: 2.79, 95% CI, 2.10-3.63; P = .50). Kaplan-Meier analysis showed no differences in the incidence of CRC between groups during the follow-up period (log-rank, 0.6). CONCLUSIONS: The risk of CRC in patients with multiple serrated polyps who do not meet the criteria for serrated polyposis, and in their first-degree relatives, is similar to that of patients diagnosed with serrated polyposis.


Assuntos
Adenoma/diagnóstico , Pólipos do Colo/genética , Pólipos do Colo/patologia , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/epidemiologia , Vigilância da População , Adenoma/patologia , Adulto , Idoso , Pólipos do Colo/diagnóstico , Colonoscopia , Neoplasias Colorretais/patologia , DNA Glicosilases/genética , Análise Mutacional de DNA , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Mutação , Linhagem , Prevalência , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Fatores de Risco , Síndrome , Carga Tumoral
7.
PLoS One ; 12(3): e0174305, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28355283

RESUMO

There is an unambiguous association of Streptococcus gallolyticus infection with colorectal cancer, although there is limited information about epidemiology or interaction between molecular and environmental factors. We performed an original quantitative analysis of S. gallolyticus in unselected colorectal cancer patients (n = 190) and their association with clinical, pathological tumor molecular profiles (microsatellite instability, hypermethylator phenotype and chromosomal instability pathways), and other biological factors in colorectal tumor and normal tissues (cytomegalovirus and Epstein-Barr virus infection). We developed a new quantitative method to assess bacterial load. Analytical validation was reached with a very high sensitivity and specificity. Our results showed a 3.2% prevalence of S. gallolyticus infection in our unselected cohort of colorectal cancer cases (6/190). The average S. gallolyticus copy number was 7,018 (range 44-34,585). No previous reports relating to S. gallolyticus infection have been published for unselected cohorts of patients. Finally, and despite a low prevalence of S. gallolyticus in this study, we were able to define a specific association with tumor tissue (p = 0.03) and with coinfection with Epstein-Barr virus (p = 0.042; OR: 9.49; 95% IC: 1.1-82.9). The prevalence data provided will be very useful in the design of future studies, and will make it possible to estimate the sample size needed to assess precise objectives. In conclusion, our results show a low prevalence of S. gallolyticus infection in unselected colorectal cancer patients and an association of positive S. gallolyticus infection with tumor tissue and Epstein-Barr virus coinfection. Further studies will be needed to definitively assess the prevalence of S. gallolyticus in colorectal cancer and the associated clinicopathological and molecular profiles.


Assuntos
Neoplasias Colorretais/microbiologia , Infecções Estreptocócicas/complicações , Streptococcus gallolyticus/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Colo/microbiologia , Colo/patologia , Neoplasias Colorretais/genética , Feminino , Humanos , Masculino , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Infecções Estreptocócicas/genética
8.
J Gene Med ; 19(4)2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28306219

RESUMO

BACKGROUND: We identified a new and a recurrent POLD1 mutation associated with predisposition to colorectal cancer (CRC). We characterized the molecular and clinical nature of the potential POLD1 founder mutation in families from Valencia (Spain). METHODS: Clinical and molecular data were collected from four independent families known to have a POLD1 Leu474Pro mutation. To establish its founder effect, haplotype construction was performed using 14 flanking POLD1 polymorphic markers. We calculated penetrance estimates and clinical expressivity, globally and stratified by age and sex. RESULTS: We included 32 individuals from the four families: 20 carriers and 12 noncarriers. A common haplotype was identified in these families in a region comprising 2,995 Mb, confirming L474P as the first founder POLD1 mutation identified. Thirteen tumors diagnosed in 10 POLD1 carriers: eight CRC, three endometrial and two other tumors were considered. The median age of cancer onset for POLD1 mutation carriers was 48 years. The observed penetrance was 50% and the cumulative risk at age of 50 years was 30%. CONCLUSIONS: The findings of the present study contribute to a better understanding of CRC genetics in the Spanish population. The clinical phenotype for this mutation is similar to that in Lynch syndrome. Future studies using next generation sequencing with large gene panels for any hereditary cancer condition will offer the possibility of detecting POLE/POLD1 mutations in unsuspected clinical situations, demonstrating a more real and unbiased picture of the associated phenotype.


Assuntos
DNA Polimerase III/genética , Grupo com Ancestrais do Continente Europeu/genética , Efeito Fundador , Genética Populacional , Mutação de Sentido Incorreto , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Neoplasias Colorretais Hereditárias sem Polipose/epidemiologia , Neoplasias Colorretais Hereditárias sem Polipose/genética , Feminino , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Haplótipos , Heterozigoto , Humanos , Masculino , Repetições de Microssatélites , Pessoa de Meia-Idade , Penetrância , Fenótipo , Polimorfismo de Nucleotídeo Único , Vigilância da População , Espanha , Adulto Jovem
9.
Hum Mol Genet ; 25(12): 2600-2611, 2016 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-26936820

RESUMO

DNA methylation (DNAm) has been linked to changes in chromatin structure, gene expression and disease. The DNAm level can be affected by genetic variation; although, how this differs by CpG dinucleotide density and genic location of the DNAm site is not well understood. Moreover, the effect of disease causing variants on the DNAm level in a tissue relevant to disease has yet to be fully elucidated. To this end, we investigated the phenotypic profiles, genetic effects and regional genomic heritability for 196080 DNAm sites in healthy colorectum tissue from 132 unrelated Colombian individuals. DNAm sites in regions of low-CpG density were more variable, on average more methylated and were more likely to be significantly heritable when compared with DNAm sites in regions of high-CpG density. DNAm sites located in intergenic regions had a higher mean DNAm level and were more likely to be heritable when compared with DNAm sites in the transcription start site (TSS) of a gene expressed in colon tissue. Within CpG-dense regions, the propensity of the DNAm level to be heritable was lower in the TSS of genes expressed in colon tissue than in the TSS of genes not expressed in colon tissue. In addition, regional genetic variation was associated with variation in local DNAm level no more frequently for DNAm sites within colorectal cancer risk regions than it was for DNAm sites outside such regions. Overall, DNAm sites located in different genomic contexts exhibited distinguishable profiles and may have a different biological function.


Assuntos
Colo/metabolismo , Metilação de DNA/genética , Epigênese Genética , Reto/metabolismo , Pólipos do Colo/genética , Pólipos do Colo/metabolismo , Ilhas de CpG/genética , Feminino , Regulação da Expressão Gênica , Genoma Humano , Genômica , Humanos , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Regiões Promotoras Genéticas
10.
J Med Genet ; 52(7): 498-502, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25908759

RESUMO

BACKGROUND: The prevalence of MLH1 constitutional epimutations in the general population is unknown. We sought to analyse the prevalence of MLH1 constitutional epimutations in unselected and selected series of patients with colorectal cancer (CRC). METHODS: Patients with diagnoses of CRC (n=2123) were included in the unselected group. For comparison, a group of 847 selected patients with CRC who fulfilled the revised Bethesda guidelines (rBG) were also included. Somatic and constitutional MLH1 methylation was assayed via methylation-specific multiplex ligation-dependent probe amplification of cases lacking MLH1 expression. Germline alterations in mismatch-repair (MMR) genes were assessed via Sanger sequencing and methylation-specific multiplex ligation-dependent probe amplification. RESULTS: Loss of MLH1 expression occurred in 5.5% of the unselected series and 12.5% of the selected series (p<0.0001). No constitutional epimutations in MLH1 were detected in the unselected population (0/62); five cases from the selected series were positive for MLH1 epimutations (15.6%, 5/32; p=0.004). CONCLUSIONS: Our results suggest a negligible prevalence of MLH1 constitutional epimutations in unselected cases of CRC. Therefore, MLH1 constitutional epimutation analysis should be conducted only for patients who fulfil the rBG and who lack MLH1 expression with methylated MLH1.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Neoplasias Colorretais Hereditárias sem Polipose/epidemiologia , Neoplasias Colorretais Hereditárias sem Polipose/genética , Metilação de DNA/genética , Epigênese Genética/genética , Mutação/genética , Proteínas Nucleares/genética , Sequência de Bases , Reparo de Erro de Pareamento de DNA/genética , Testes Genéticos/normas , Humanos , Repetições de Microssatélites/genética , Dados de Sequência Molecular , Proteína 1 Homóloga a MutL , Prevalência , Regiões Promotoras Genéticas/genética , Análise de Sequência de DNA , Estatísticas não Paramétricas
11.
BMC Cancer ; 15: 240, 2015 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-25885658

RESUMO

BACKGROUND: Colorectal carcinoma is a common cause of cancer. Adjuvant treatments include: 5-fluorouracil administered together with folinic acid, or more recently, oral fluoropyrimidines such as capecitabine, in combination with oxaliplatin or irinotecan. Metastatic colorectal cancer patients can benefit from other additional treatments such as cetuximab or bevacizumab. METHODS: Using cell culture techniques, we isolated clonal populations from primary cultures of ascitic effusion derived from a colon cancer patient and after several passages an established cell line, HGUE-C-1, was obtained. Genetic analysis of HGUE-C-1 cells was performed by PCR of selected exons and sequencing. Cell proliferation studies were performed by MTT assays and cell cycle analyses were performed by flow cytometry. Retinoblastoma activity was measured by luciferase assays and proteins levels and activity were analysed by Western blot or immunohistochemistry. RESULTS: We have established a new cell line from ascitic efussion of a colon cancer patient who did not respond to 5-fluorouracil or irinotecan. HGUE-C-1 cells did not show microsatellite instability and did not harbour mutations in KRAS, BRAF, PI3KCA or TP53. However, these cells showed loss of heterozygosity affecting Adenomatous Polyposis Coli and nuclear staining of ß-catenin protein. The HGUE-C-1 cell line was sensitive to erlotinib, gefitinib, NVP-BEZ235, rapamycin and trichostatin, among other drugs, but partially resistant to heat shock protein inhibitors and highly resistant to AZD-6244 and oxaliplatin, even though the patient from which this cell line was derived had not been exposed to these drugs. Molecular characterization of this cell line revealed low expression levels and activity of Retinoblastoma protein and elevated basal levels of Erk1/2 activity and p70S6K expression and activity, which may be related to chemoresistance mechanisms. CONCLUSIONS: HGUE-C-1 represents a novel and peculiar colon carcinoma model to study chemoresistance to chemotherapeutic agents and to novel anti-neoplasic drugs that interrupt signalling pathways such as the APC/ßcatenin, Ras/Raf/Mek/Erk, PI3K/mTOR/p70S6K pathways as well as histone regulation mechanisms.


Assuntos
Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Idoso , Antineoplásicos/farmacologia , Biomarcadores , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/patologia , Análise Mutacional de DNA , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos , Expressão Gênica , Humanos , Masculino , Instabilidade de Microssatélites , Mutação , Fenótipo , Inibidores de Proteínas Quinases/farmacologia , Transdução de Sinais
12.
Eur J Cancer ; 50(13): 2241-50, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24953332

RESUMO

BACKGROUND AND AIMS: Individuals with tumours showing mismatch repair (MMR) deficiency not linked to germline mutations or somatic methylation of MMR genes have been recently referred as having 'Lynch-like syndrome' (LLS). The genetic basis of these LLS cases is unknown. MUTYH-associated polyposis patients show some phenotypic similarities to Lynch syndrome patients. The aim of this study was to investigate the prevalence of germline MUTYH mutations in a large series of LLS patients. METHODS: Two hundred and twenty-five probands fulfilling LLS criteria were included in this study. Screening of MUTYH recurrent mutations, whole coding sequencing and a large rearrangement analysis were undertaken. Age, sex, clinical, pathological and molecular characteristics of tumours including KRAS mutations were assessed. RESULTS: We found a prevalence of 3.1% of MAP syndrome in the whole series of LLS (7/225) and 3.9% when only cases fulfilling clinical criteria were considered (7/178). Patients with MUTYH biallelic mutations had more adenomas than monoallelic (P=0.02) and wildtype patients (P<0.0001). Six out of nine analysed tumours from six biallelic MUTYH carriers harboured KRAS-p.G12C mutation. This mutation was found to be associated with biallelic MUTYH germline mutation when compared with reported series of unselected colorectal cancer cohorts (P<0.0001). CONCLUSIONS: A proportion of unexplained LLS cases is caused by biallelic MUTYH mutations. The obtained results further justify the inclusion of MUTYH in the diagnostic strategy for Lynch syndrome-suspected patients.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/genética , DNA Glicosilases/genética , Mutação em Linhagem Germinativa , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas p21(ras) , Proteínas ras/genética
13.
Hum Mol Genet ; 23(13): 3506-12, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24501277

RESUMO

Germline mutations in DNA polymerase ɛ (POLE) and δ (POLD1) have been recently identified in families with multiple colorectal adenomas and colorectal cancer (CRC). All reported cases carried POLE c.1270C>G (p.Leu424Val) or POLD1 c.1433G>A (p.Ser478Asn) mutations. Due to the scarcity of cases reported so far, an accurate clinical phenotype has not been defined. We aimed to assess the prevalence of these recurrent mutations in unexplained familial and early-onset CRC and polyposis, and to add additional information to define the clinical characteristics of mutated cases. A total of 858 familial/early onset CRC and polyposis patients were studied: 581 familial and early-onset CRC cases without mismatch repair (MMR) deficiency, 86 cases with MMR deficiency and 191 polyposis cases. Mutation screening was performed by KASPar genotyping assays and/or Sanger sequencing of the involved exons. POLE p.L424V was identified in a 28-year-old polyposis and CRC patient, as a de novo mutation. None of the 858 cases studied carried POLD1 p.S478N. A new mutation, POLD1 c.1421T>C (p.Leu474Pro), was identified in a mismatch repair proficient Amsterdam II family. Its pathogenicity was supported by cosegregation in the family, in silico predictions, and previously published yeast assays. POLE and POLD1 mutations explain a fraction of familial CRC and polyposis. Sequencing the proofreading domains of POLE and POLD1 should be considered in routine genetic diagnostics. Until additional evidence is gathered, POLE and POLD1 genetic testing should not be restricted to polyposis cases, and the presence of de novo mutations, considered.


Assuntos
Polipose Adenomatosa do Colo/genética , Neoplasias Colorretais/genética , DNA Polimerase III/genética , DNA Polimerase II/genética , Mutação em Linhagem Germinativa/genética , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas de Ligação a Poli-ADP-Ribose
14.
Clin Cancer Res ; 20(5): 1158-68, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-24470512

RESUMO

PURPOSE: The present study aimed to determine the prevalence of MUTYH mutations in patients with multiple colonic polyps and to explore the best strategy for diagnosing MUTYH-associated polyposis (MAP) in these patients. EXPERIMENTAL DESIGN: This study included 405 patients with at least 10 colonic polyps each. All cases were genetically tested for the three most frequent MUTYH mutations. Whole-gene analysis was performed in heterozygous patients and in 216 patients lacking the three most frequent mutations. Polyps from 56 patients were analyzed for the KRAS-Gly12Cys and BRAF V600E somatic mutations. RESULTS: Twenty-seven (6.7%) patients were diagnosed with MAP, of which 40.8% showed serrated polyps. The sensitivity of studying only the three common variants was 74.1%. Of 216 patients without any monoallelic mutation in common variants, whole-gene analysis revealed biallelic pathogenic mutation in only one. G396D mutation was associated with serrated lesions and older age at diagnosis. There was a strong association between germinal MUTYH mutation and KRAS Gly12Cys somatic mutation in polyps. BRAF V600E mutation was found in 74% of serrated polyps in MUTYH-negative patients and in none of the polyps of MAP patients. CONCLUSIONS: We observed a low frequency of MUTYH mutations among patients with multiple adenomatous and serrated polyps. The MAP phenotype frequently included patients with serrated polyps, especially when G396D mutation was involved. Our results show that somatic molecular markers of polyps can be useful in identifying MAP cases and support the need for the complete MUTYH gene analysis only in patients heterozygous for recurrent variants.


Assuntos
Polipose Adenomatosa do Colo/diagnóstico , Polipose Adenomatosa do Colo/genética , Pólipos do Colo/genética , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/genética , DNA Glicosilases/genética , Mutação , Adolescente , Adulto , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Pólipos do Colo/patologia , Feminino , Genes ras , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Prevalência , Proteínas Proto-Oncogênicas B-raf/genética , Adulto Jovem
15.
PLoS One ; 8(11): e79737, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24244552

RESUMO

BACKGROUND: Lynch syndrome (LS) is a hereditary condition that increases the risk for endometrial and other cancers. The identification of endometrial cancer (EC) patients with LS has the potential to influence life-saving interventions. We aimed to study the prevalence of LS among EC patients in our population. METHODS: Universal screening for LS was applied for a consecutive series EC. Tumor testing using microsatellite instability (MSI), immunohistochemistry (IHC) for mismatch-repair (MMR) protein expression and MLH1-methylation analysis, when required, was used to select LS-suspicious cases. Sequencing of corresponding MMR genes was performed. RESULTS: One hundred and seventy-three EC (average age, 63 years) were screened. Sixty-one patients (35%) had abnormal IHC or MSI results. After MLH1 methylation analysis, 27 cases were considered suspicious of LS. From these, 22 were contacted and referred for genetic counseling. Nineteen pursued genetic testing and eight were diagnosed of LS. Mutations were more frequent in younger patients (<50 yrs). Three cases had either intact IHC or MSS and reinforce the need of implement the EC screening with both techniques. CONCLUSION: The prevalence of LS among EC patients was 4.6% (8/173); with a predictive frequency of 6.6% in the Spanish population. Universal screening of EC for LS is recommended.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/complicações , Neoplasias Colorretais Hereditárias sem Polipose/epidemiologia , Neoplasias do Endométrio/complicações , Proteínas Adaptadoras de Transdução de Sinal/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Metilação de DNA , Reparo de Erro de Pareamento de DNA , Neoplasias do Endométrio/diagnóstico , Feminino , Mutação em Linhagem Germinativa , Humanos , Imuno-Histoquímica , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL , Gradação de Tumores , Estadiamento de Neoplasias , Proteínas Nucleares/genética , Prevalência
16.
APMIS ; 121(12): 1139-43, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23510386

RESUMO

Circulating tumor cell (CTC) enumeration is important clinically for identifying prognostic and predictive factors in patients with solid cancers. The CellSearch device (Veridex) is an immunomagnetic CTC selection and enumeration system used in clinical practice. The ImageStream (Amnis) combines the strengths of flow cytometry and fluorescent microscopy in a single platform and has potential application for CTC counting. The performance in CTC enumeration was compared between the ImageStream and CellSearch systems. Various numbers of PANC-1 tumor cells were spiked into 7.5 mL of peripheral blood from a healthy donor. Before cell analysis by the ImageStream, tumor cell enrichment was performed by immunomagnetic selection with anti-EpPCAM. Anti-CD45 and anti-CK markers were used to discriminate between tumor cells and leukocytes. The ratios of tumor cells recovered from each dilution were calculated for both methods. The Wilcoxon rank test was applied to compare the results of the two methods and the reference value. The results of the two tested methods differed significantly from the reference value, but did not differ between them. Nevertheless, lower level of trueness and precision was observed in ImageStream when fewer numbers of CTCs were analyzed. Our results suggest that ImageStream platform for CTC enumeration has a potential value for the early diagnosis of disseminated disease, but needs an improvement of precision for the enumeration of low number of CTC.


Assuntos
Biomarcadores Tumorais/sangue , Citometria por Imagem/métodos , Células Neoplásicas Circulantes/imunologia , Neoplasias Pancreáticas/sangue , Anticorpos Monoclonais , Antígenos de Neoplasias/imunologia , Moléculas de Adesão Celular/imunologia , Contagem de Células/métodos , Linhagem Celular Tumoral , Separação Celular , Molécula de Adesão da Célula Epitelial , Humanos , Antígenos Comuns de Leucócito/imunologia , Leucócitos/imunologia
17.
Gastroenterology ; 144(5): 926-932.e1; quiz e13-4, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23354017

RESUMO

BACKGROUND & AIMS: Colorectal cancers (CRCs) with microsatellite instability (MSI) and a mismatch repair (MMR) immunohistochemical deficit without hypermethylation of the MLH1 promoter are likely to be caused by Lynch syndrome. Some patients with these cancers have not been found to have pathogenic germline mutations and are considered to have Lynch-like syndrome (LLS). The aim of this study was to determine the risk of cancer in families of patients with LLS. METHODS: We studied a population-based cohort of 1705 consecutive patients, performing MSI tests and immunohistochemical analyses of MMR proteins. Patients were diagnosed with Lynch syndrome when they were found to have pathogenic germline mutations. Patients with MSI and loss of MSH2 and/or MSH6 expression, isolated loss of PMS2 or loss of MLH1 without MLH1 promoter hypermethylation, and no pathogenic mutation were considered to have LLS. The clinical characteristics of patients and the age- and sex-adjusted standardized incidence ratios (SIRs) of cancer in families were compared between groups. RESULTS: The incidence of CRC was significantly lower in families of patients with LLS than in families with confirmed cases of Lynch syndrome (SIR for Lynch syndrome, 6.04; 95% confidence interval [CI], 3.58-9.54; SIR for LLS, 2.12; 95% CI, 1.16-3.56; P < .001). However, the incidence of CRC was higher in families of patients with LLS than in families with sporadic CRC (SIR for sporadic CRC, 0.48; 95% CI, 0.27-0.79; P < .001). CONCLUSIONS: The risk of cancer in families with LLS is lower that of families with Lynch syndrome but higher than that of families with sporadic CRC. These results confirm the need for special screening and surveillance strategies for these patients and their relatives.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Neoplasias Colorretais Hereditárias sem Polipose/epidemiologia , DNA de Neoplasias/genética , Proteínas Nucleares/genética , Vigilância da População , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Neoplasias Colorretais Hereditárias sem Polipose/genética , Reparo de Erro de Pareamento de DNA , Reparo do DNA , Feminino , Mutação em Linhagem Germinativa , Humanos , Imuno-Histoquímica , Incidência , Masculino , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL , Proteínas Nucleares/metabolismo , Fatores de Risco , Espanha/epidemiologia
19.
PLoS One ; 7(1): e30812, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22292045

RESUMO

In colorectal cancer (CRC), an inherited susceptibility risk affects about 35% of patients, whereas high-penetrance germline mutations account for <6% of cases. A considerable proportion of sporadic tumors could be explained by the coinheritance of multiple low-penetrance variants, some of which are common. We assessed the susceptibility to CRC conferred by genetic variants at the TGFBR1 locus. We analyzed 14 polymorphisms and the allele-specific expression (ASE) of TGFBR1 in 1025 individuals from the Spanish population. A case-control study was undertaken with 504 controls and 521 patients with sporadic CRC. Fourteen polymorphisms located at the TGFBR1 locus were genotyped with the iPLEX Gold (MassARRAY-Sequenom) technology. Descriptive analyses of the polymorphisms and haplotypes and association studies were performed with the SNPator workpackage. No relevant associations were detected between individual polymorphisms or haplotypes and the risk of CRC. The TGFBR1*9A/6A polymorphism was used for the ASE analysis. Heterozygous individuals were analyzed for ASE by fragment analysis using cDNA from normal tissue. The relative level of allelic expression was extrapolated from a standard curve. The cutoff value was calculated with Youden's index. ASE was found in 25.4% of patients and 16.4% of controls. Considering both bimodal and continuous types of distribution, no significant differences between the ASE values of patients and controls were identified. Interestingly, a combined analysis of the polymorphisms and ASE for the association with CRC occurrence revealed that ASE-positive individuals carrying one of the most common haplotypes (H2: 20.7%) showed remarkable susceptibility to CRC (RR: 5.25; 95% CI: 2.547-5.250; p<0.001) with a synergy factor of 3.7. In our study, 54.1% of sporadic CRC cases were attributable to the coinheritance of the H2 haplotype and TGFBR1 ASE. These results support the hypothesis that the allelic architecture of cancer genes, rather than individual polymorphisms, more accurately defines the CRC risk.


Assuntos
Carcinoma/genética , Neoplasias Colorretais/genética , Epistasia Genética/fisiologia , Loci Gênicos , Proteínas Serina-Treonina Quinases/genética , Receptores de Fatores de Crescimento Transformadores beta/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma/epidemiologia , Estudos de Casos e Controles , Neoplasias Colorretais/epidemiologia , Feminino , Loci Gênicos/genética , Loci Gênicos/fisiologia , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético/fisiologia , Proteínas Serina-Treonina Quinases/fisiologia , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptores de Fatores de Crescimento Transformadores beta/fisiologia , Fatores de Risco , Adulto Jovem
20.
Gut ; 61(6): 865-72, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21868491

RESUMO

BACKGROUND: The selection of patients for genetic testing to rule out Lynch syndrome is currently based on fulfilment of at least one of the revised Bethesda criteria followed by mismatch repair (MMR) status analysis. A study was undertaken to compare the present approach with universal MMR study-based strategies to detect Lynch syndrome in a large series of patients with colorectal cancer (CRC). METHODS: 2093 patients with CRC from the EPICOLON I and II cohorts were included. Immunohistochemistry for MMR proteins and/or microsatellite instability (MSI) analysis was performed in tumour tissue. Germline MLH1 and MSH2 mutation analysis was performed in patients whose tumours showed loss of MLH1 or MSH2 staining, respectively. MSH6 genetic testing was done in patients whose tumours showed lack of MSH6 expression or a combined lack of MSH2 and MSH6 expression but did not have MSH2 mutations. PMS2 genetic testing was performed in patients showing isolated loss of PMS2 expression. In patients with MSI tumours and normal or not available MMR protein expression, all four MMR genes were studied. RESULTS: A total of 180 patients (8.6%) showed loss of expression of some of the MMR proteins and/or MSI. Four hundred and eighty-six patients (23.2%) met some of the revised Bethesda criteria. Of the 14 (0.7%) patients who had a MMR gene mutation, 12 fulfilled at least one of the revised Bethesda criteria and two (14.3%) did not. CONCLUSIONS: Routine molecular screening of patients with CRC for Lynch syndrome using immunohistochemistry or MSI has better sensitivity for detecting mutation carriers than the Bethesda guidelines.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Neoplasias Colorretais/diagnóstico , Proteínas Adaptadoras de Transdução de Sinal/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Neoplasias Colorretais Hereditárias sem Polipose/genética , Neoplasias Colorretais Hereditárias sem Polipose/patologia , Metilação de DNA , Reparo de Erro de Pareamento de DNA/genética , Feminino , Triagem de Portadores Genéticos/métodos , Testes Genéticos/métodos , Mutação em Linhagem Germinativa/genética , Humanos , Imuno-Histoquímica/métodos , Masculino , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL , Proteína 2 Homóloga a MutS/genética , Proteínas Nucleares/genética , Guias de Prática Clínica como Assunto
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