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1.
Cells ; 9(12)2020 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-33322746

RESUMO

Germline alterations in many genes coding for proteins regulating DNA repair and DNA damage response (DDR) to DNA double-strand breaks (DDSB) have been recognized as pathogenic factors in hereditary cancer predisposition. The ATM-CHEK2-p53 axis has been documented as a backbone for DDR and hypothesized as a barrier against cancer initiation. However, although CHK2 kinase coded by the CHEK2 gene expedites the DDR signal, its function in activation of p53-dependent cell cycle arrest is dispensable. CHEK2 mutations rank among the most frequent germline alterations revealed by germline genetic testing for various hereditary cancer predispositions, but their interpretation is not trivial. From the perspective of interpretation of germline CHEK2 variants, we review the current knowledge related to the structure of the CHEK2 gene, the function of CHK2 kinase, and the clinical significance of CHEK2 germline mutations in patients with hereditary breast, prostate, kidney, thyroid, and colon cancers.

2.
Biomedicines ; 8(10)2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33050356

RESUMO

Cutaneous melanoma is the deadliest skin malignity with a rising prevalence worldwide. Patients carrying germline mutations in melanoma-susceptibility genes face an increased risk of melanoma and other cancers. To assess the spectrum of germline variants, we analyzed 264 Czech melanoma patients indicated for testing due to early melanoma (at <25 years) or the presence of multiple primary melanoma/melanoma and other cancer in their personal and/or family history. All patients were analyzed by panel next-generation sequencing targeting 217 genes in four groups: high-to-moderate melanoma risk genes, low melanoma risk genes, cancer syndrome genes, and other genes with an uncertain melanoma risk. Population frequencies were assessed in 1479 population-matched controls. Selected POT1 and CHEK2 variants were characterized by functional assays. Mutations in clinically relevant genes were significantly more frequent in melanoma patients than in controls (31/264; 11.7% vs. 58/1479; 3.9%; p = 2.0 × 10-6). A total of 9 patients (3.4%) carried mutations in high-to-moderate melanoma risk genes (CDKN2A, POT1, ACD) and 22 (8.3%) patients in other cancer syndrome genes (NBN, BRCA1/2, CHEK2, ATM, WRN, RB1). Mutations in high-to-moderate melanoma risk genes (OR = 52.2; 95%CI 6.6-413.1; p = 3.2 × 10-7) and in other cancer syndrome genes (OR = 2.3; 95%CI 1.4-3.8; p = 0.003) were significantly associated with melanoma risk. We found an increased potential to carry these mutations (OR = 2.9; 95%CI 1.2-6.8) in patients with double primary melanoma, melanoma and other primary cancer, but not in patients with early age at onset. The analysis revealed affected genes in Czech melanoma patients and identified individuals who may benefit from genetic testing and future surveillance management of mutation carriers.

3.
Cancers (Basel) ; 12(4)2020 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-32295079

RESUMO

Ovarian cancer (OC) is the deadliest gynecologic malignancy with a substantial proportion of hereditary cases and a frequent association with breast cancer (BC). Genetic testing facilitates treatment and preventive strategies reducing OC mortality in mutation carriers. However, the prevalence of germline mutations varies among populations and many rarely mutated OC predisposition genes remain to be identified. We aimed to analyze 219 genes in 1333 Czech OC patients and 2278 population-matched controls using next-generation sequencing. We revealed germline mutations in 18 OC/BC predisposition genes in 32.0% of patients and in 2.5% of controls. Mutations in BRCA1/BRCA2, RAD51C/RAD51D, BARD1, and mismatch repair genes conferred high OC risk (OR > 5). Mutations in BRIP1 and NBN were associated with moderate risk (both OR = 3.5). BRCA1/2 mutations dominated in almost all clinicopathological subgroups including sporadic borderline tumors of ovary (BTO). Analysis of remaining 201 genes revealed somatic mosaics in PPM1D and germline mutations in SHPRH and NAT1 associating with a high/moderate OC risk significantly; however, further studies are warranted to delineate their contribution to OC development in other populations. Our findings demonstrate the high proportion of patients with hereditary OC in Slavic population justifying genetic testing in all patients with OC, including BTO.

4.
J Clin Oncol ; 38(7): 674-685, 2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-31841383

RESUMO

PURPOSE: To estimate age-specific relative and absolute cancer risks of breast cancer and to estimate risks of ovarian, pancreatic, male breast, prostate, and colorectal cancers associated with germline PALB2 pathogenic variants (PVs) because these risks have not been extensively characterized. METHODS: We analyzed data from 524 families with PALB2 PVs from 21 countries. Complex segregation analysis was used to estimate relative risks (RRs; relative to country-specific population incidences) and absolute risks of cancers. The models allowed for residual familial aggregation of breast and ovarian cancer and were adjusted for the family-specific ascertainment schemes. RESULTS: We found associations between PALB2 PVs and risk of female breast cancer (RR, 7.18; 95% CI, 5.82 to 8.85; P = 6.5 × 10-76), ovarian cancer (RR, 2.91; 95% CI, 1.40 to 6.04; P = 4.1 × 10-3), pancreatic cancer (RR, 2.37; 95% CI, 1.24 to 4.50; P = 8.7 × 10-3), and male breast cancer (RR, 7.34; 95% CI, 1.28 to 42.18; P = 2.6 × 10-2). There was no evidence for increased risks of prostate or colorectal cancer. The breast cancer RRs declined with age (P for trend = 2.0 × 10-3). After adjusting for family ascertainment, breast cancer risk estimates on the basis of multiple case families were similar to the estimates from families ascertained through population-based studies (P for difference = .41). On the basis of the combined data, the estimated risks to age 80 years were 53% (95% CI, 44% to 63%) for female breast cancer, 5% (95% CI, 2% to 10%) for ovarian cancer, 2%-3% (95% CI females, 1% to 4%; 95% CI males, 2% to 5%) for pancreatic cancer, and 1% (95% CI, 0.2% to 5%) for male breast cancer. CONCLUSION: These results confirm PALB2 as a major breast cancer susceptibility gene and establish substantial associations between germline PALB2 PVs and ovarian, pancreatic, and male breast cancers. These findings will facilitate incorporation of PALB2 into risk prediction models and optimize the clinical cancer risk management of PALB2 PV carriers.

5.
Sci Rep ; 9(1): 17050, 2019 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-31745173

RESUMO

The most common histological subtypes of cutaneous melanoma include superficial spreading and nodular melanoma. However, the spectrum of somatic mutations developed in those lesions and all potential druggable targets have not yet been fully elucidated. We present the results of a sequence capture NGS analysis of 114 primary nodular and superficial spreading melanomas identifying driver mutations using biostatistical, immunohistochemical and/or functional approach. The spectrum and frequency of pathogenic or likely pathogenic variants were identified across 54 evaluated genes, including 59 novel mutations, and the newly identified TP53 loss-of-function mutations p.(L194P) and p.(R280K). Frequently mutated genes most commonly affected the MAPK pathway, followed by chromatin remodeling, and cell cycle regulation. Frequent aberrations were also detected in the genes coding for proteins involved in DNA repair and the regulation and modification of cellular tight junctions. Furthermore, relatively frequent mutations were described in KDR and MET, which represent potential clinically important targets. Those results suggest that with the development of new therapeutic possibilities, not only BRAF testing, but complex molecular testing of cutaneous melanoma may become an integral part of the decision process concerning the treatment of patients with melanoma.


Assuntos
Predisposição Genética para Doença/genética , Mutação com Perda de Função/genética , Melanoma/genética , Neoplasias Cutâneas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Ciclo Celular/genética , Montagem e Desmontagem da Cromatina/genética , Reparo do DNA/genética , Feminino , Frequência do Gene/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Sistema de Sinalização das MAP Quinases/genética , Masculino , Melanoma/patologia , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas B-raf/genética , Neoplasias Cutâneas/patologia , Junções Íntimas/genética , Proteína Supressora de Tumor p53/genética , Adulto Jovem
6.
Cell Death Dis ; 10(11): 818, 2019 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-31659152

RESUMO

Protein phosphatase magnesium-dependent 1 delta (PPM1D) terminates cell response to genotoxic stress by negatively regulating the tumor suppressor p53 and other targets at chromatin. Mutations in the exon 6 of the PPM1D result in production of a highly stable, C-terminally truncated PPM1D. These gain-of-function PPM1D mutations are present in various human cancers but their role in tumorigenesis remains unresolved. Here we show that truncated PPM1D impairs activation of the cell cycle checkpoints in human non-transformed RPE cells and allows proliferation in the presence of DNA damage. Next, we developed a mouse model by introducing a truncating mutation in the PPM1D locus and tested contribution of the oncogenic PPM1DT allele to colon tumorigenesis. We found that p53 pathway was suppressed in colon stem cells harboring PPM1DT resulting in proliferation advantage under genotoxic stress condition. In addition, truncated PPM1D promoted tumor growth in the colon in Apcmin mice and diminished survival. Moreover, tumor organoids derived from colon of the ApcminPpm1dT/+ mice were less sensitive to 5-fluorouracil when compared to ApcminPpm1d+/+and the sensitivity to 5-fluorouracil was restored by inhibition of PPM1D. Finally, we screened colorectal cancer patients and identified recurrent somatic PPM1D mutations in a fraction of colon adenocarcinomas that are p53 proficient and show defects in mismatch DNA repair. In summary, we provide the first in vivo evidence that truncated PPM1D can promote tumor growth and modulate sensitivity to chemotherapy.


Assuntos
Proteína da Polipose Adenomatosa do Colo/genética , Neoplasias do Colo/tratamento farmacológico , Proteína Fosfatase 2C/genética , Proteína Supressora de Tumor p53/genética , Animais , Carcinogênese/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/genética , Proliferação de Células/efeitos dos fármacos , Cromatina/efeitos dos fármacos , Neoplasias do Colo/genética , Neoplasias do Colo/patologia , Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Éxons/genética , Fluoruracila/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Mutação/genética
7.
Klin Onkol ; 32(Supplementum2): 6-13, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31409076

RESUMO

An inherited predisposition to breast cancer underlies 5-10% of breast tumors. High-risk BRCA1 and BRCA2 genes result in an 85% lifetime risk of breast cancer and a 20-60% lifetime risk of ovarian cancer. Next-generation sequencing or massive parallel sequencing are now established testing methods that enable screening for many genes that predispose to heterogeneous hereditary cancer syndromes (22 genes are required by the health insurance companies). In addition to BRCA1 and BRCA2, inherited mutations in other genes predispose to breast and/or ovarian cancer. High-risk breast cancer genes include TP53, STK11, CDH1, PTEN, PALB2, and NF1, while moderate-risk (2-4 times increased risk) breast cancer genes include ATM, CHEK2, and NBN. Moderate risk is also suggested for Lynch syndrome, MUTYH, BRIP1, RAD51C, RAD51D, BARD1, FANCA, FANCC, FANCM, BLM, WRN genes. In heterozygotes for other recessive syndromes the risk of developing breast cancer is subject to current research. Low-risk genes are (mostly) irrelevant from a clinical perspective. Other genes that increase the risk of ovarian cancer include the genes for Lynch syndrome, the BRIP1, RAD51C and RAD51D genes. Preventive care should be proposed based on assumed cumulative breast cancer risk (see http: //www.mamo.cz): a risk of >20% for BRCA1/2, TP53, PTEN, STK11, CDH1, PALB2, CHEK2, ATM, and NF1; and a risk of 10-20% for BRIP1, RAD51C, RAD51B, BARD1, FANCA, FANCC, FANCM, NBN, BLM, and WRN. The genetic risk should be assessed by a geneticist and be based on inherited mutations and empirical risk according to family history. Prophylactic mastectomy is considered for high-risk gene carriers but not for moderate-risk gene carriers; however, it may be considered if there is an underlying family history, a risk of parenchyma of the mammary gland, or other risk factors. Ovarian cancer risk increases significantly in carriers of the BRIP1, RAD51C, and RAD51D genes. For prevention of ovarian cancer, prophylactic salpingo-oophorectomy is an important component of preventive care. In ovarian cancer families with no identified risk germline mutation, preventive salpingo-oophorectomy is not routinely recommended but may be considered as the only efficient method of prevention due to the increased empirical risk (4 times) of ovarian cancer in first-degree relatives. Supported by the grant project MH CZ - RVO (MMCI, 00209805), AZV 15-27695A and AZV 16-29959A. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 17. 5. 2019 Accepted: 31. 5. 2019.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/prevenção & controle , Predisposição Genética para Doença , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/prevenção & controle , Feminino , Humanos , Mastectomia Profilática , Fatores de Risco , Salpingo-Ooforectomia
8.
Klin Onkol ; 32(Supplementum2): 36-50, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31409080

RESUMO

BACKGROUND: Hereditary mutations in the CHEK2 gene (which encodes CHK2 kinase) contribute to a moderately increased risk of breast cancer (BC) and other cancers. Large variations in the frequency of CHEK2 mutations and the occurrence of variants of unknown clinical significance (VUS) complicate estimation of cancer risk in carriers of germline CHEK2 mutations. PATIENTS AND METHODS: We performed mutation analysis of 1,526 high-risk Czech BC patients and 3,360 Czech controls. Functional analysis was performed for identified VUS using a model system based on a human RPE1-CHEK2-KO cell line harboring biallelic inactivation of endogenous CHEK2. RESULTS: The frequency of ten truncating CHEK2 variants differed markedly between BC patients (2.26%) and controls (0.11%; p = 4.1 × 1012). We also found 23 different missense variants in 4.5% patients and in 4.0% of controls. The most common was p.I157T, which was found in patients and controls with the same frequency. Functional analysis identified nine functionally deleterious VUS, another nine functionally neutral VUS, and four intermediate VUS (including p.I157T). We found that carriers of truncating CHEK2 mutations had a high BC risk (OR 8.19; 95% CI 4.11-17.75), and that carriers of functionally deleterious missense variants had a moderate risk (OR 4.06; 95% CI, 1.37-13.39). Carriers of these mutations developed BC at 44.4 and 50.7 years, respectively. Functionally neutral and functionally intermediate missense variants did not increase the BC risk. BC in CHEK2 mutation carriers was frequently ER-positive and of higher grade. Notably, carriers of CHEK2 mutations developed second cancers more frequently than BRCA1/BRCA2/PALB2/p53 or mutation non-carriers. CONCLUSION: Hereditary CHEK2 mutations contribute to the development of hereditary BC. The associated cancer risk in mutation carriers increases with the number of affected individuals in a family. Annual follow-up with breast ultrasound, mammography, or magnetic resonance imaging is recommended for asymptomatic mutation carriers from the age of 40. Surgical prevention and specific follow-up of other tumors should be considered based on family cancer history. The work was supported by grants from the Czech Health Research Council of the Ministry of Health of the Czech Republic NR 15-28830A, 16-29959A, NV19-03-00279, projects of the PROGRES Q28/LF1, GAUK 762216, SVV2019 / 260367, PRIMUS/17/MED/9, UNCE/MED/016, Progress Q26, LQ1604 NPU II and project AVČR Qualitas. The analysis of a set of unselected controls was made possible by the existence and support of the scientific infrastructure of the National Center for Medical Genomics (LM2015091) and its project aimed at creating a reference database of genetic variants of the Czech Republic (CZ.02.1.01/0.0/0.0/16_013/0001634). The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 2. 4. 2019 Accepted: 14. 5. 2019.


Assuntos
Neoplasias da Mama/genética , Quinase do Ponto de Checagem 2/genética , Predisposição Genética para Doença , Linhagem Celular , República Tcheca , Feminino , Mutação em Linhagem Germinativa , Humanos , Fatores de Risco
9.
Klin Onkol ; 32(Supplementum2): 72-78, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31409082

RESUMO

BACKGROUND: Ovarian cancer is a disease with high mortality. Approximately 1,000 women are diagnosed with ovarian cancer in the Czech Republic annually. Women harboring a mutation in cancer-predisposing genes face an increased risk of tumor development. Mutations in BRCA1, BRCA2, BRIP1, and Lynch syndrome genes (RAD51C, RAD51D, and STK11) are associated with a high risk of ovarian cancer, and mutations in ATM, CHEK2, NBN, PALB2, and BARD1 appear to increase the risk. Our aim was to examine the frequency of mutations in cancer-predisposing genes in the Czech Republic. MATERIALS AND METHODS: We analyzed 1,057 individuals including ovarian cancer patients and 617 non-cancer controls using CZECANCA panel next-generation sequencing on the Illumina platform. Pathogenic mutations in high-risk genes, including CNVs, were detected in 30.6% of patients. The mutation frequency reached 25.0% and 18.2% in subgroups of unselected ovarian cancer patients and patients with a negative family cancer history, respectively. The most frequently mutated genes were BRCA1 and BRCA2. The overall frequency of mutations in non-BRCA genes was comparable to that in BRCA2. The mutation frequency in ovarian cancer patients aged >70 years was three times higher than that in patients diagnosed before the age of 30. CONCLUSION: Ovarian cancer is a heterogeneous disease with a high proportion of hereditary cases. The lack of efficient screening for early diagnosis emphasizes the importance of identifying carriers of mutations in ovarian cancer-predisposing genes; this is because proper follow-up and prevention strategies can reduce overall ovarian cancer-related mortality. This work was supported by grants AZV 15-27695A, SVV2019/260367, PROGRES Q28/LF1. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 7. 3. 2019 Accepted: 24. 4. 2019.


Assuntos
Proteína BRCA1/genética , Proteína BRCA2/genética , Predisposição Genética para Doença , Neoplasias Ovarianas/genética , República Tcheca , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Mutação
10.
Cancers (Basel) ; 11(6)2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31141992

RESUMO

Breast cancer (BC) prognosis in BRCA1 and BRCA2 mutation carriers has been reported contradictorily, and the significance of variables influencing prognosis in sporadic BC is not established in BC patients with hereditary BRCA1/BRCA2 mutations. In this retrospective cohort study, we analyzed the effect of clinicopathological characteristics on BC prognosis (disease-free survival [DFS] and disease-specific survival [DSS]) in hereditary BRCA1/BRCA2 mutation carriers. We enrolled 234 BRCA1/BRCA2 mutation carriers and 899 non-carriers, of whom 191 carriers and 680 non-carriers, with complete data, were available for survival analyses. We found that patients with ER-positive tumors developed disease recurrence 2.3-times more likely when they carried a BRCA1/BRCA2 mutation (23/60; 38.3% ER-positive carriers vs. 74/445; 16.6% ER-positive non-carriers; p < 0.001). ER-positive mutation carriers also had a 3.4-times higher risk of death due to BC compared with ER-positive non-carriers (13/60; 21.7% vs. 28/445; 6.3%; p < 0.001). Moreover, prognosis in ER-negative BRCA1/BRCA2 mutation carriers was comparable with that in ER-positive non-carriers. Our study demonstrates that ER-positivity worsens BC prognosis in BRCA1/BRCA2 mutation carriers, while prognosis for carriers with ER-negative tumors (including early-onset) is significantly better and comparable with that in ER-positive, older BC non-carriers. These observations indicate that BRCA1/BRCA2 mutation carriers with ER-positive BC represent high-risk patients.

11.
Int J Cancer ; 145(7): 1782-1797, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31050813

RESUMO

Germline mutations in checkpoint kinase 2 (CHEK2), a multiple cancer-predisposing gene, increase breast cancer (BC) risk; however, risk estimates differ substantially in published studies. We analyzed germline CHEK2 variants in 1,928 high-risk Czech breast/ovarian cancer (BC/OC) patients and 3,360 population-matched controls (PMCs). For a functional classification of VUS, we developed a complementation assay in human nontransformed RPE1-CHEK2-knockout cells quantifying CHK2-specific phosphorylation of endogenous protein KAP1. We identified 10 truncations in 46 (2.39%) patients and in 11 (0.33%) PMC (p = 1.1 × 10-14 ). Two types of large intragenic rearrangements (LGR) were found in 20/46 mutation carriers. Truncations significantly increased unilateral BC risk (OR = 7.94; 95%CI 3.90-17.47; p = 1.1 × 10-14 ) and were more frequent in patients with bilateral BC (4/149; 2.68%; p = 0.003), double primary BC/OC (3/79; 3.80%; p = 0.004), male BC (3/48; 6.25%; p = 8.6 × 10-4 ), but not with OC (3/354; 0.85%; p = 0.14). Additionally, we found 26 missense VUS in 88 (4.56%) patients and 131 (3.90%) PMC (p = 0.22). Using our functional assay, 11 variants identified in 15 (0.78%) patients and 6 (0.18%) PMC were scored deleterious (p = 0.002). Frequencies of functionally intermediate and neutral variants did not differ between patients and PMC. Functionally deleterious CHEK2 missense variants significantly increased BC risk (OR = 3.90; 95%CI 1.24-13.35; p = 0.009) and marginally OC risk (OR = 4.77; 95%CI 0.77-22.47; p = 0.047); however, carriers low frequency will require evaluation in larger studies. Our study highlights importance of LGR detection for CHEK2 analysis, careful consideration of ethnicity in both cases and controls for risk estimates, and demonstrates promising potential of newly developed human nontransformed cell line assay for functional CHEK2 VUS classification.


Assuntos
Neoplasias da Mama Masculina/genética , Neoplasias da Mama/genética , Quinase do Ponto de Checagem 2/genética , Mutação em Linhagem Germinativa , Neoplasias Ovarianas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Linhagem Celular , República Tcheca , Feminino , Técnicas de Inativação de Genes , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Deleção de Sequência , Adulto Jovem
12.
Hum Mutat ; 40(5): 631-648, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30851065

RESUMO

Genetic testing for cancer predisposition leads to the identification of a number of variants with uncertain significance. To some extent, variants of BRCA1/2 have been classified, in contrast to variants of other genes. CHEK2 is a typical example, in which a large number of variants of unknown clinical significance were identified and still remained unclassified. Herein, the CHEK2 variant assessment was performed through an in vivo, yeast-based, functional assay. In total, 120 germline CHEK2 missense variants, distributed along the protein sequence, and two large in-frame deletions were tested, originating from genetic test results in breast cancer families, or selected from the ClinVar database. Of these, 32 missense and two in-frame deletions behaved as non-functional, 73 as functional, and 15 as semi-functional, after comparing growth rates of each strain with positive and negative controls. The majority of non-functional variants were localized in the CHK2 kinase and forkhead-associated domains. In vivo results from the non-functional variants were in agreement with in silico predictions, and, where available, with strong breast cancer family history, to a great extent. The results of the largest, to date, yeast-based assay, evaluating CHEK2 variants, can complement and assist in the classification of rare CHEK2 variants with unclear clinical significance.


Assuntos
Quinase do Ponto de Checagem 2/genética , Mutação , Saccharomyces cerevisiae/genética , Alelos , Substituição de Aminoácidos , Quinase do Ponto de Checagem 2/metabolismo , Biologia Computacional/métodos , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Modelos Moleculares , Linhagem , Conformação Proteica , Saccharomyces cerevisiae/metabolismo
13.
Cancer Manag Res ; 11: 599-609, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30666157

RESUMO

Background: The principal aim of this report was to study second primary malignant neoplasms (SMNs) in long-term survivors of pancreatic ductal adenocarcinoma (PDAC) with regard to the germline genetic background. Patients and methods: A total of 118 PDAC patients after a curative-intent surgery who were treated between 2006 and 2011 were analyzed. Of the 22 patients surviving for >5 years, six went on to develop SMNs. A genetic analysis of 219 hereditary cancer-predisposition and candidate genes was performed by targeted next-generation sequencing in germline DNA from 20 of these patients. Results: Of all the radically resected PDAC patients, six patients went on to subsequently develop SMNs, which accounted for 27% of the long-term survivors. The median time to diagnosis of SMNs, which included two cases of rectal cancer, and one case each of prostate cancer, malignant melanoma, breast cancer, and urinary bladder cancer, was 52.5 months. At the time of analysis, none of these patients had died as a result of PDAC progression. We identified four carriers of germline pathogenic mutations in 20 analyzed long-term survivors. One carrier of the CHEK2 mutation was found among four analyzed patients who developed SMNs. Of the remaining 16 long-term PDAC survivors, 3 patients (19%) carried germline mutation(s) in the MLH1+ ATM, CHEK2, and RAD51D gene, respectively. Conclusion: This retrospective analysis indicates that SMNs in PDAC survivors are an important clinical problem and may be more common than has been acknowledged to be the case. In patients with good performance status, surgical therapy should be considered, as the SMNs often have a favorable prognosis.

14.
PLoS One ; 13(4): e0195761, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29649263

RESUMO

BACKGROUND: Carriers of mutations in hereditary cancer predisposition genes represent a small but clinically important subgroup of oncology patients. The identification of causal germline mutations determines follow-up management, treatment options and genetic counselling in patients' families. Targeted next-generation sequencing-based analyses using cancer-specific panels in high-risk individuals have been rapidly adopted by diagnostic laboratories. While the use of diagnosis-specific panels is straightforward in typical cases, individuals with unusual phenotypes from families with overlapping criteria require multiple panel testing. Moreover, narrow gene panels are limited by our currently incomplete knowledge about possible genetic dispositions. METHODS: We have designed a multi-gene panel called CZECANCA (CZEch CAncer paNel for Clinical Application) for a sequencing analysis of 219 cancer-susceptibility and candidate predisposition genes associated with frequent hereditary cancers. RESULTS: The bioanalytical and bioinformatics pipeline was validated on a set of internal and commercially available DNA controls showing high coverage uniformity, sensitivity, specificity and accuracy. The panel demonstrates a reliable detection of both single nucleotide and copy number variants. Inter-laboratory, intra- and inter-run replicates confirmed the robustness of our approach. CONCLUSION: The objective of CZECANCA is a nationwide consolidation of cancer-predisposition genetic testing across various clinical indications with savings in costs, human labor and turnaround time. Moreover, the unified diagnostics will enable the integration and analysis of genotypes with associated phenotypes in a national database improving the clinical interpretation of variants.


Assuntos
Biomarcadores Tumorais , Sequenciamento de Nucleotídeos em Larga Escala , Síndromes Neoplásicas Hereditárias/genética , Biologia Computacional/métodos , Variações do Número de Cópias de DNA , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Testes Genéticos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Sequenciamento de Nucleotídeos em Larga Escala/normas , Humanos , Mutação INDEL , Masculino , Mutação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
15.
Gene ; 637: 41-49, 2017 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-28919163

RESUMO

Alternative pre-mRNA splicing increases transcriptome plasticity by forming naturally-occurring alternative splicing variants (ASVs). Alterations of splicing processes, caused by DNA mutations, result in aberrant splicing and the formation of aberrant mRNA isoforms. Analyses of hereditary cancer predisposition genes reveal many DNA variants with unknown clinical significance (VUS) that potentially affect pre-mRNA splicing. Therefore, a comprehensive description of ASVs is an essential prerequisite for the interpretation of germline VUS in high-risk individuals. To identify ASVs in a gene of interest, we have proposed an approach based on multiplex PCR (mPCR) amplification of all theoretically possible exon-exon junctions and subsequent characterization of size-selected and pooled mPCR products by next-generation sequencing (NGS). The efficiency of this method is illustrated by a comprehensive analysis of BRCA1 ASVs in human leukocytes, normal mammary, and adipose tissues and stable cell lines. We revealed 94 BRCA1 ASVs, including 29 variants present in all tested samples. While differences in the qualitative expression of BRCA1 ASVs among the analyzed human tissues were minor, larger differences were detected between tissue and cell line samples. Compared with other ASV analysis methods, this approach represents a highly sensitive and rapid alternative for the identification of ASVs in any gene of interest.


Assuntos
Processamento Alternativo , Proteína BRCA1/genética , Neoplasias da Mama/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Reação em Cadeia da Polimerase Multiplex/métodos , Mutação , Biologia Computacional , Feminino , Humanos , Isoformas de RNA
16.
PLoS Genet ; 12(8): e1006248, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27504877

RESUMO

The increasing application of gene panels for familial cancer susceptibility disorders will probably lead to an increased proposal of susceptibility gene candidates. Using ERCC2 DNA repair gene as an example, we show that proof of a possible role in cancer susceptibility requires a detailed dissection and characterization of the underlying mutations for genes with diverse cellular functions (in this case mainly DNA repair and basic cellular transcription). In case of ERCC2, panel sequencing of 1345 index cases from 587 German, 405 Lithuanian and 353 Czech families with breast and ovarian cancer (BC/OC) predisposition revealed 25 mutations (3 frameshift, 2 splice-affecting, 20 missense), all absent or very rare in the ExAC database. While 16 mutations were unique, 9 mutations showed up repeatedly with population-specific appearance. Ten out of eleven mutations that were tested exemplarily in cell-based functional assays exert diminished excision repair efficiency and/or decreased transcriptional activation capability. In order to provide evidence for BC/OC predisposition, we performed familial segregation analyses and screened ethnically matching controls. However, unlike the recently published RECQL example, none of our recurrent ERCC2 mutations showed convincing co-segregation with BC/OC or significant overrepresentation in the BC/OC cohort. Interestingly, we detected that some deleterious founder mutations had an unexpectedly high frequency of > 1% in the corresponding populations, suggesting that either homozygous carriers are not clinically recognized or homozygosity for these mutations is embryonically lethal. In conclusion, we provide a useful resource on the mutational landscape of ERCC2 mutations in hereditary BC/OC patients and, as our key finding, we demonstrate the complexity of correct interpretation for the discovery of "bonafide" breast cancer susceptibility genes.


Assuntos
Neoplasias da Mama/genética , Predisposição Genética para Doença , Neoplasias Ovarianas/genética , Proteína Grupo D do Xeroderma Pigmentoso/genética , Neoplasias da Mama/patologia , Reparo do DNA/genética , Feminino , Mutação em Linhagem Germinativa , Heterozigoto , Humanos , Mutação de Sentido Incorreto , Neoplasias Ovarianas/patologia , Proteína Grupo D do Xeroderma Pigmentoso/química
17.
Breast ; 28: 136-44, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27318168

RESUMO

The presence of breast cancer in any first-degree female relative in general nearly doubles the risk for a proband and the risk gradually increases with the number of affected relatives. Current advances in molecular oncology and oncogenetics may enable the identification of high-risk individuals with breast-cancer predisposition. The best-known forms of hereditary breast cancer (HBC) are caused by mutations in the high-penetrance genes BRCA1 and BRCA2. Other genes, including PTEN, TP53, STK11/LKB1, CDH1, PALB2, CHEK2, ATM, MRE11, RAD50, NBS1, BRIP1, FANCA, FANCC, FANCM, RAD51, RAD51B, RAD51C, RAD51D, and XRCC2 have been described as high- or moderate-penetrance breast cancer-susceptibility genes. The majority of breast cancer-susceptibility genes code for tumor suppressor proteins that are involved in critical processes of DNA repair pathways. This is of particular importance for those women who, due to their increased risk of breast cancer, may be subjected to more frequent screening but due to their repair deficiency might be at the risk of developing radiation-induced malignancies. It has been proven that cancers arising from the most frequent BRCA1 gene mutation carriers differ significantly from the sporadic disease of age-matched controls in their histopathological appearances and molecular characteristics. The increased depth of mutation detection brought by next-generation sequencing and a better understanding of the mechanisms through which these mutations cause the disease will bring novel insights in terms of oncological prevention, diagnostics, and therapeutic options for HBC patients.


Assuntos
Neoplasias da Mama/genética , Predisposição Genética para Doença , Antígenos CD , Proteínas Mutadas de Ataxia Telangiectasia/genética , Biomarcadores , Neoplasias da Mama/patologia , Caderinas/genética , Quinase do Ponto de Checagem 2/genética , Proteína do Grupo de Complementação N da Anemia de Fanconi , Feminino , Genes BRCA1 , Genes BRCA2 , Humanos , Mutação , Proteínas Nucleares/genética , PTEN Fosfo-Hidrolase/genética , Penetrância , Proteínas Serina-Treonina Quinases/genética , Fatores de Risco , Proteína Supressora de Tumor p53/genética , Proteínas Supressoras de Tumor/genética
18.
Gene ; 587(2): 169-72, 2016 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-27150568

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is the sixth most frequent cancer type in the Czech Republic with a poor prognosis that could be improved by an early detection and subsequent surgical treatment combined with chemotherapy. Genetic factors play an important role in PDAC risk. We previously identified one PDAC patient harboring the Slavic founder deleterious mutation c.657del5 in the NBN gene, using a panel next-generation sequencing (NGS). A subsequent analysis of 241 unselected PDAC patients revealed other mutation carriers. The overall frequency of c.657del5 in unselected PDAC patients (5/241; 2.07%) significantly differed from that in non-cancer controls (2/915; 0.2%; P=0.006). The result indicates that the NBN c.657del5 variant represents a novel PDAC-susceptibility allele increasing PDAC risk (OR=9.7; 95% CI: 1.9 to 50.2). The increased risk of PDAC in follow-up recommendations for NBN mutation carriers should be considered if other studies also confirm an increased frequency of c.657del5 carriers in PDAC patients from other populations.


Assuntos
Adenocarcinoma/genética , Carcinoma Ductal Pancreático/genética , Proteínas de Ciclo Celular/genética , Deleção de Genes , Proteínas Nucleares/genética , Neoplasias Pancreáticas/genética , Tchecoslováquia , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem
19.
Lancet Oncol ; 16(16): 1639-50, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26603945

RESUMO

BACKGROUND: The best-known cause of intolerance to fluoropyrimidines is dihydropyrimidine dehydrogenase (DPD) deficiency, which can result from deleterious polymorphisms in the gene encoding DPD (DPYD), including DPYD*2A and c.2846A>T. Three other variants-DPYD c.1679T>G, c.1236G>A/HapB3, and c.1601G>A-have been associated with DPD deficiency, but no definitive evidence for the clinical validity of these variants is available. The primary objective of this systematic review and meta-analysis was to assess the clinical validity of c.1679T>G, c.1236G>A/HapB3, and c.1601G>A as predictors of severe fluoropyrimidine-associated toxicity. METHODS: We did a systematic review of the literature published before Dec 17, 2014, to identify cohort studies investigating associations between DPYD c.1679T>G, c.1236G>A/HapB3, and c.1601G>A and severe (grade ≥3) fluoropyrimidine-associated toxicity in patients treated with fluoropyrimidines (fluorouracil, capecitabine, or tegafur-uracil as single agents, in combination with other anticancer drugs, or with radiotherapy). Individual patient data were retrieved and analysed in a multivariable analysis to obtain an adjusted relative risk (RR). Effect estimates were pooled by use of a random-effects meta-analysis. The threshold for significance was set at a p value of less than 0·0167 (Bonferroni correction). FINDINGS: 7365 patients from eight studies were included in the meta-analysis. DPYD c.1679T>G was significantly associated with fluoropyrimidine-associated toxicity (adjusted RR 4·40, 95% CI 2·08-9·30, p<0·0001), as was c.1236G>A/HapB3 (1·59, 1·29-1·97, p<0·0001). The association between c.1601G>A and fluoropyrimidine-associated toxicity was not significant (adjusted RR 1·52, 95% CI 0·86-2·70, p=0·15). Analysis of individual types of toxicity showed consistent associations of c.1679T>G and c.1236G>A/HapB3 with gastrointestinal toxicity (adjusted RR 5·72, 95% CI 1·40-23·33, p=0·015; and 2·04, 1·49-2·78, p<0·0001, respectively) and haematological toxicity (adjusted RR 9·76, 95% CI 3·03-31·48, p=0·00014; and 2·07, 1·17-3·68, p=0·013, respectively), but not with hand-foot syndrome. DPYD*2A and c.2846A>T were also significantly associated with severe fluoropyrimidine-associated toxicity (adjusted RR 2·85, 95% CI 1·75-4·62, p<0·0001; and 3·02, 2·22-4·10, p<0·0001, respectively). INTERPRETATION: DPYD variants c.1679T>G and c.1236G>A/HapB3 are clinically relevant predictors of fluoropyrimidine-associated toxicity. Upfront screening for these variants, in addition to the established variants DPYD*2A and c.2846A>T, is recommended to improve the safety of patients with cancer treated with fluoropyrimidines. FUNDING: None.


Assuntos
Antimetabólitos Antineoplásicos/efeitos adversos , Antimetabólitos Antineoplásicos/farmacocinética , Di-Hidrouracila Desidrogenase (NADP)/genética , Gastroenteropatias/genética , Doenças Hematológicas/genética , Neoplasias/tratamento farmacológico , Polimorfismo Genético , Capecitabina/efeitos adversos , Capecitabina/farmacocinética , Di-Hidrouracila Desidrogenase (NADP)/metabolismo , Fluoruracila/efeitos adversos , Fluoruracila/farmacocinética , Gastroenteropatias/induzido quimicamente , Gastroenteropatias/diagnóstico , Predisposição Genética para Doença , Doenças Hematológicas/induzido quimicamente , Doenças Hematológicas/diagnóstico , Humanos , Análise Multivariada , Neoplasias/diagnóstico , Neoplasias/genética , Razão de Chances , Farmacogenética , Fenótipo , Medição de Risco , Fatores de Risco , Índice de Gravidade de Doença , Tegafur/efeitos adversos , Tegafur/farmacocinética
20.
PLoS One ; 10(10): e0140819, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26506619

RESUMO

The checkpoint kinase 2 gene (CHEK2) codes for the CHK2 protein, an important mediator of the DNA damage response pathway. The CHEK2 gene has been recognized as a multi-cancer susceptibility gene; however, its role in non-Hodgkin lymphoma (NHL) remains unclear. We performed mutation analysis of the entire CHEK2 coding sequence in 340 NHL patients using denaturing high-performance liquid chromatography (DHPLC) and multiplex ligation-dependent probe amplification (MLPA). Identified hereditary variants were genotyped in 445 non-cancer controls. The influence of CHEK2 variants on disease risk was statistically evaluated. Identified CHEK2 germline variants included four truncating mutations (found in five patients and no control; P = 0.02) and nine missense variants (found in 21 patients and 12 controls; P = 0.02). Carriers of non-synonymous variants had an increased risk of NHL development [odds ratio (OR) 2.86; 95% confidence interval (CI) 1.42-5.79] and an unfavorable prognosis [hazard ratio (HR) of progression-free survival (PFS) 2.1; 95% CI 1.12-4.05]. In contrast, the most frequent intronic variant c.319+43dupA (identified in 22% of patients and 31% of controls) was associated with a decreased NHL risk (OR = 0.62; 95% CI 0.45-0.86), but its positive prognostic effect was limited to NHL patients with diffuse large B-cell lymphoma (DLBCL) treated by conventional chemotherapy without rituximab (HR-PFS 0.4; 94% CI 0.17-0.74). Our results show that germ-line CHEK2 mutations affecting protein coding sequence confer a moderately-increased risk of NHL, they are associated with an unfavorable NHL prognosis, and they may represent a valuable predictive biomarker for patients with DLBCL.


Assuntos
Quinase do Ponto de Checagem 2/genética , Predisposição Genética para Doença , Linfoma não Hodgkin/genética , Prognóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise Mutacional de DNA , Reparo do DNA/genética , Feminino , Estudos de Associação Genética , Células Germinativas , Humanos , Linfoma não Hodgkin/patologia , Masculino , Pessoa de Meia-Idade , Mutação , Processamento de RNA/genética
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