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Cancer is considered by not only multiple genetic but also epigenetic amendments that drive malignant cell propagation and consult chemo-resistance. The ability to correct or ablate such mutations holds enormous promise for battling cancer. Recently, because of its great efficiency and feasibility, the CRISPR-Cas9 advanced genome editing technique has been extensively considered for therapeutic investigations of cancers. Several studies have used the CRISPR-Cas9 technique for editing cancer cell genomic DNA in cells and animal cancer models and have shown therapeutic potential in intensifying anti-cancer protocols. Moreover, CRISPR-Cas9 may be used to correct oncogenic mutations, discover anticancer drugs, and engineer immune cells and oncolytic viruses for immunotherapeutic treatment of cancer. We herein discuss the challenges and opportunities for translating therapeutic methods with CRISPR-Cas9 for clinical use and suggest potential directions of the CRISPR-Cas9 system for future cancer therapy.
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The United Arab Emirates (UAE) is one of the fastest growing economies with consequent increase in non-communicable diseases including cancer. The number of reported cases and mortality have been increasing in the UAE over the years, despite screening and early detection efforts which appear to be far from target coverage of the intended population. In this work, we highlight key elements of a proposed national cancer control plan for the UAE. The plan is still a work in progress and has not yet been officially adopted. A comprehensive and effective control plan requires accurate data, a reliable cancer registry, and periodic monitoring and evaluation. The UAE cancer control plan is being prepared in line with the WHO and EMRO framework, with defined objectives and goals. The objectives are to combat cancer, reduce incidence, control mortality, and improve outcomes and quality of life for cancer patients. There is also a focus on improving public health education, prevention, early detection, prompt diagnosis, treatment facilitation, continuity of care, performance evaluation, training of workforce, and research.
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BACKGROUND: Epertinib (S-222611) is a potent reversible inhibitor of HER2, EGFR and HER4. This trial evaluated the safety, tolerability, pharmacokinetics and antitumour activity of daily oral epertinib combined with trastuzumab (arm A), with trastuzumab plus vinorelbine (arm B) or with trastuzumab plus capecitabine (arm C), in patients with HER2-positive metastatic breast cancer (MBC). METHODS: Eligible patients, with or without brain metastases, had received prior HER2-directed therapy. A dose-escalation phase determined the tolerability of each combination and established a dose for further study. Further, patients were recruited to expansion cohorts in each of the 3 arms to further explore efficacy and safety. RESULTS: The recommended doses of epertinib were 600 mg, 200 mg and 400 mg in arms A, B and C, respectively. The most frequent grade 3/4 adverse event (AE) was diarrhoea in all arms, which was manageable with medical intervention and dose modification. The objective response rate (complete response [CR] plus partial response [PR]) in heavily pre-treated HER2-positive MBC patients at the recommended doses of epertinib combined with trastuzumab was 67% (N = 9), with trastuzumab plus vinorelbine was 0% (N = 5) and with trastuzumab plus capecitabine was 56% (N = 9). Notably, 4 of 6 patients previously treated with T-DM1 responded in the arm A expansion cohort (epertinib plus trastuzumab). In the arm C expansion cohort (epertinib plus trastuzumab plus capecitabine), 4 of 7 patients responded despite previous exposure to capecitabine. Measurable regression of brain metastases was observed in patients with CNS target lesions treated in both arms A and C. CONCLUSION: We observed safety, tolerability and encouraging antitumour activity of epertinib combined with trastuzumab, or with trastuzumab plus capecitabine. This supports further evaluation of these combinations in patients with pre-treated HER2-positive MBC, with or without brain metastases. TRIAL REGISTRATION: EudraCT Number: 2013-003894-87; registered 09-September-2013.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Quinazolinas/uso terapêutico , Receptor ErbB-2/metabolismo , Trastuzumab/uso terapêutico , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/secundário , Neoplasias da Mama/patologia , Capecitabina/administração & dosagem , Capecitabina/efeitos adversos , Capecitabina/uso terapêutico , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Quinazolinas/administração & dosagem , Quinazolinas/efeitos adversos , Receptor ErbB-2/antagonistas & inibidores , Trastuzumab/administração & dosagem , Trastuzumab/efeitos adversos , Resultado do Tratamento , Vinorelbina/administração & dosagem , Vinorelbina/efeitos adversos , Vinorelbina/uso terapêuticoRESUMO
The British Gynaecological Cancer Society has issued the first Endometrial (Uterine) Cancer guidelines as recommendation for practice for the UK.
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Neoplasias Uterinas/terapia , Biópsia , Diagnóstico por Imagem , Neoplasias do Endométrio/diagnóstico , Neoplasias do Endométrio/patologia , Neoplasias do Endométrio/terapia , Feminino , Preservação da Fertilidade , Neoplasias dos Genitais Femininos , Humanos , Terapia Neoadjuvante , Cuidados Pré-Operatórios , Fatores de Risco , Reino Unido , Neoplasias Uterinas/diagnóstico , Neoplasias Uterinas/prevenção & controleRESUMO
BACKGROUND: The PARP inhibitor olaparib was recently granted Food and Drug Administration (FDA) accelerated approval in patients with advanced BRCA1/2 mutation ovarian cancer. However, antitumor responses are observed in only approximately 40% of patients and the impact of baseline clinical factors on response to treatment remains unclear. Although platinum sensitivity has been suggested as a marker of response to PARP inhibitors, patients with platinum-resistant disease still respond to olaparib. RESULTS: 108 patients with advanced BRCA1/2 mutation ovarian cancers were included. The interval between the end of the most recent platinum chemotherapy and PARPi (PTPI) was used to predict response to olaparib independent of conventional definition of platinum sensitivity. RECIST complete response (CR) and partial response (PR) rates were 35% in patients with platinum-sensitive versus 13% in platinum-resistant (p<0.005). Independent of platinum sensitivity status, the RECIST CR/PR rates were 42% in patients with PTPI greater than 52 weeks and 18% in patients with PTPI less than 52 weeks (p=0.016). No association was found between baseline clinical factors such as FIGO staging, debulking surgery, BRCA1 versus BRCA2 mutations, prior history of breast cancer and prior chemotherapy for breast cancer, and the response to olaparib. METHODS: We conducted an international multicenter retrospective study to investigate the association between baseline clinical characteristics of patients with advanced BRCA1/2 mutation ovarian cancers from eight different cancer centers and their antitumor response to olaparib. CONCLUSION: PTPI may be used to refine the prediction of response to PARP inhibition based on the conventional categorization of platinum sensitivity.
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Antineoplásicos/uso terapêutico , Proteína BRCA1/genética , Proteína BRCA2/genética , Mutação em Linhagem Germinativa , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Ftalazinas/uso terapêutico , Piperazinas/uso terapêutico , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Adulto , Idoso , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Feminino , Humanos , Pessoa de Meia-Idade , Gradação de Tumores , Metástase Neoplásica , Estadiamento de Neoplasias , Neoplasias Ovarianas/mortalidade , Neoplasias Ovarianas/patologia , Ftalazinas/administração & dosagem , Ftalazinas/efeitos adversos , Piperazinas/administração & dosagem , Piperazinas/efeitos adversos , Inibidores de Poli(ADP-Ribose) Polimerases/administração & dosagem , Inibidores de Poli(ADP-Ribose) Polimerases/efeitos adversos , Prognóstico , Recidiva , Análise de Sobrevida , Resultado do TratamentoRESUMO
Talazoparib inhibits PARP catalytic activity, trapping PARP1 on damaged DNA and causing cell death in BRCA1/2-mutated cells. We evaluated talazoparib therapy in this two-part, phase I, first-in-human trial. Antitumor activity, MTD, pharmacokinetics, and pharmacodynamics of once-daily talazoparib were determined in an open-label, multicenter, dose-escalation study (NCT01286987). The MTD was 1.0 mg/day, with an elimination half-life of 50 hours. Treatment-related adverse events included fatigue (26/71 patients; 37%) and anemia (25/71 patients; 35%). Grade 3 to 4 adverse events included anemia (17/71 patients; 24%) and thrombocytopenia (13/71 patients; 18%). Sustained PARP inhibition was observed at doses ≥0.60 mg/day. At 1.0 mg/day, confirmed responses were observed in 7 of 14 (50%) and 5 of 12 (42%) patients with BRCA mutation-associated breast and ovarian cancers, respectively, and in patients with pancreatic and small cell lung cancer. Talazoparib demonstrated single-agent antitumor activity and was well tolerated in patients at the recommended dose of 1.0 mg/day.Significance: In this clinical trial, we show that talazoparib has single-agent antitumor activity and a tolerable safety profile. At its recommended phase II dose of 1.0 mg/day, confirmed responses were observed in patients with BRCA mutation-associated breast and ovarian cancers and in patients with pancreatic and small cell lung cancer. Cancer Discov; 7(6); 620-9. ©2017 AACR.This article is highlighted in the In This Issue feature, p. 539.
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Antineoplásicos/uso terapêutico , Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias/tratamento farmacológico , Ftalazinas/uso terapêutico , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacologia , Feminino , Mutação em Linhagem Germinativa , Humanos , Leucócitos Mononucleares/enzimologia , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Neoplasias/enzimologia , Neoplasias/genética , Ftalazinas/administração & dosagem , Ftalazinas/efeitos adversos , Ftalazinas/farmacologia , Poli(ADP-Ribose) Polimerase-1/sangue , Inibidores de Poli(ADP-Ribose) Polimerases/administração & dosagem , Inibidores de Poli(ADP-Ribose) Polimerases/efeitos adversos , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Resultado do Tratamento , Adulto JovemRESUMO
Drug resistance to conventional anticancer therapies is almost inevitable in patients with advanced ovarian cancer (AOC), limiting their available treatment options. Novel phase I trial therapies within a dedicated drug development unit may represent a viable alternative; however, there is currently little evidence for patient outcomes in such patients. To address this, we undertook a retrospective review of patients with AOC allocated to phase I trials in the Drug Development Unit at Royal Marsden Hospital (RMH) between June 1998 and October 2010. A total of 200 AOC patients with progressive disease were allocated to ≥1 trial each, with a total of 281 allocations. Of these, 135 (68%) patients commenced ≥1 trial (mean 1.4 [1-8]), totaling 216 allocated trials; 65 (32%) patients did not start due to deterioration resulting from rapidly progressive disease (63 patients) or patient choice (2 patients). Response Evaluation Criteria in Solid Tumours (RECIST) complete/partial responses (CR/PR) were observed in 43 (20%) of those starting trials, including those on poly(ADP-ribose) polymerase (PARP) inhibitors (18/79 [23%]), antiangiogenics (9/65 [14%]) and chemotherapy combinations (14/43 [33%]). Factors associated with CR/PR included: fewer prior treatments, platinum-sensitive disease, CR/PR with prior therapy, (the United States-based) Eastern Cooperative Oncology Group (ECOG) performance status score, fewer metastatic sites, higher albumin and haemoglobin levels, lower white cell counts and baseline CA125 levels, germline BRCA1/2 mutations and better RMH Prognostic Score. Mean survival was 32° months for patients who achieved CR/PR. Treatments were generally well tolerated. Most patients with AOC (134/200 [67%]) received ≥1 subsequent line of therapy after phase I trials. Our data suggest that phase I trial referrals should be considered earlier in the AOC treatment pathway and before the onset of rapid disease progression particularly with the emergence of promising novel agents in the era of precision medicine.
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Adenocarcinoma de Células Claras/tratamento farmacológico , Antineoplásicos/uso terapêutico , Carcinoma Endometrioide/tratamento farmacológico , Carcinossarcoma/tratamento farmacológico , Ensaios Clínicos Fase I como Assunto , Tumor de Células da Granulosa/tratamento farmacológico , Neoplasias Císticas, Mucinosas e Serosas/tratamento farmacológico , Neoplasias Ovarianas/tratamento farmacológico , Adenocarcinoma de Células Claras/genética , Adenocarcinoma de Células Claras/metabolismo , Adenocarcinoma de Células Claras/patologia , Adulto , Idoso , Antígeno Ca-125/metabolismo , Carcinoma Endometrioide/genética , Carcinoma Endometrioide/metabolismo , Carcinoma Endometrioide/patologia , Carcinossarcoma/genética , Carcinossarcoma/metabolismo , Carcinossarcoma/patologia , Descoberta de Drogas , Inglaterra , Feminino , Genes BRCA1 , Genes BRCA2 , Tumor de Células da Granulosa/genética , Tumor de Células da Granulosa/metabolismo , Tumor de Células da Granulosa/patologia , Hemoglobinas/metabolismo , Síndrome Hereditária de Câncer de Mama e Ovário/genética , Humanos , Contagem de Leucócitos , Proteínas de Membrana/metabolismo , Pessoa de Meia-Idade , Metástase Neoplásica , Neoplasias Císticas, Mucinosas e Serosas/genética , Neoplasias Císticas, Mucinosas e Serosas/metabolismo , Neoplasias Císticas, Mucinosas e Serosas/patologia , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Prognóstico , Estudos Retrospectivos , Albumina Sérica/metabolismo , Índice de Gravidade de Doença , Taxa de Sobrevida , Resultado do TratamentoRESUMO
PURPOSE: To investigate the safety and efficacy of durvalumab, a human monoclonal antibody that binds programmed cell death ligand-1 (PD-L1), and the role of PD-L1 expression on clinical response in patients with advanced urothelial bladder cancer (UBC). METHODS: A phase 1/2 multicenter, open-label study is being conducted in patients with inoperable or metastatic solid tumors. We report here the results from the UBC expansion cohort. Durvalumab (MEDI4736, 10 mg/kg every 2 weeks) was administered intravenously for up to 12 months. The primary end point was safety, and objective response rate (ORR, confirmed) was a key secondary end point. An exploratory analysis of pretreatment tumor biopsies led to defining PD-L1-positive as ≥ 25% of tumor cells or tumor-infiltrating immune cells expressing membrane PD-L1. RESULTS: A total of 61 patients (40 PD-L1-positive, 21 PD-L1-negative), 93.4% of whom received one or more prior therapies for advanced disease, were treated (median duration of follow-up, 4.3 months). The most common treatment-related adverse events (AEs) of any grade were fatigue (13.1%), diarrhea (9.8%), and decreased appetite (8.2%). Grade 3 treatment-related AEs occurred in three patients (4.9%); there were no treatment-related grade 4 or 5 AEs. One treatment-related AE (acute kidney injury) resulted in treatment discontinuation. The ORR was 31.0% (95% CI, 17.6 to 47.1) in 42 response-evaluable patients, 46.4% (95% CI, 27.5 to 66.1) in the PD-L1-positive subgroup, and 0% (95% CI, 0.0 to 23.2) in the PD-L1-negative subgroup. Responses are ongoing in 12 of 13 responding patients, with median duration of response not yet reached (range, 4.1+ to 49.3+ weeks). CONCLUSION: Durvalumab demonstrated a manageable safety profile and evidence of meaningful clinical activity in PD-L1-positive patients with UBC, many of whom were heavily pretreated.
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Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/uso terapêutico , Antígeno B7-H1/antagonistas & inibidores , Neoplasias da Bexiga Urinária/tratamento farmacológico , Urotélio/efeitos dos fármacos , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais/efeitos adversos , Antineoplásicos/efeitos adversos , Antígeno B7-H1/metabolismo , Biópsia , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Resultado do Tratamento , Neoplasias da Bexiga Urinária/metabolismo , Neoplasias da Bexiga Urinária/mortalidade , Neoplasias da Bexiga Urinária/patologia , Urotélio/metabolismo , Urotélio/patologiaRESUMO
PURPOSE: Novel antitumor therapies against the PI3K-AKT-mTOR pathway are increasingly used to treat cancer, either as single agents or in combination with chemotherapy or other targeted therapies. Although these agents are not known to be myelosuppressive, an increased risk of infection has been reported with rapamycin analogues. However, the risk of infection with new inhibitors of this pathway such as PI3K, AKT, mTORC 1/2, or multikinase inhibitors is unknown. EXPERIMENTAL DESIGN: In this retrospective case-control study, we determined the incidence of infection in a group of 432 patients who were treated on 15 phase I clinical trials involving PI3K-AKT-mTOR pathway inhibitors (cases) versus a group of 100 patients on 10 phase I clinical trials of single agent non-PI3K-AKT-mTOR pathway inhibitors (controls) which did not involve conventional cytotoxic agents. We also collected data from 42 patients who were treated with phase I trials of combinations of PI3K-AKT-mTOR inhibitors and MEK inhibitors and 24 patients with combinations of PI3K-AKT-mTOR inhibitors and cytotoxic chemotherapies. RESULTS: The incidence of all grade infection was significantly higher with all single-agent PI3K-AKT-mTOR inhibitors compared with the control group [27% vs. 8%, respectively, OR, 4.26; 95% confidence intervals (CI), 1.9-9.1, P = 0.0001]. The incidence of grade 3 and 4 infection was also significantly higher with PI3K-AKT-mTOR inhibitors compared with the control group (10.3% vs. 3%, OR, 3.74; 95% CI, 1.1-12.4; P = 0.02). Also, the combination of PI3K-AKT-mTOR inhibitors and chemotherapy was associated with a significantly higher incidence of all grade (OR, 4.79; 95% CI, 2.0-11.2; P = 0.0001) and high-grade (OR, 2.87; 95% CI, 1.0-7.6; P = 0.03) infection when compared with single-agent PI3K-AKT-mTOR inhibitors. CONCLUSIONS: Inhibitors of the PI3K-AKT-mTOR pathway can be associated with a higher risk of infection. Combinations of PI3K-AKT-mTOR inhibitors and cytotoxic chemotherapy significantly increase the risk of infection. This should be taken into consideration during the design and conduct of trials involving PI3K-AKT-mTOR pathway inhibitors, particularly when combined with chemotherapy or myelosuppressive agents.
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Antineoplásicos/uso terapêutico , Infecções/epidemiologia , Infecções/etiologia , Neoplasias/complicações , Neoplasias/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores , Estudos de Casos e Controles , Ensaios Clínicos Fase I como Assunto , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Estadiamento de Neoplasias , Neoplasias/diagnóstico , Neoplasias/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/efeitos adversos , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Estudos Retrospectivos , Risco , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/antagonistas & inibidores , Adulto JovemRESUMO
Until recently, the weight of evidence has supported the discontinuation of chemotherapy in advanced non-small-cell lung cancer (NSCLC) after 4-6 cycles of induction therapy. This allows patients with limited life expectancy a "treatment holiday." A minority of cases then go on to receive second-line therapy, although many deteriorate rapidly and never receive further active treatment. There has been renewed interest in the concept of maintenance from trials with pemetrexed and erlotinib. Both these agents can be given for long periods without serious cumulative toxicity in most patients. Both trials have shown significant extension of progression free survival in placebo-controlled trials. In cases who are not receiving pemetrexed as induction therapy, a statistically significant 5-month prolongation of overall survival in nonsquamous NSCLC has been reported. Treatment was well tolerated. This effect may reflect the early administration of an active second-line agent and it remains to be seen whether similar benefits will accrue to patients having pemetrexed as induction therapy.
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The XRCC3 variant T241M, but not D213N, has been reported to be associated with an increased risk of some cancers. XRCC3 is one out of five RAD51 paralogues and is involved in homologous recombination, as are the BRCA1 and BRCA2 proteins. However, in contrast to mutations in BRCA1 and BRCA2, the XRCC3(T241M) protein is proficient in homologous recombination and reverts sensitivity to mitomycin C found in XRCC3-deficient cells, whereas XRCC3(D213N) is defective in homologous recombination. Here, we report that both the XRCC3 D213N and T241M alleles are associated with an increase in centrosome number and binucleated cells. However, only the D213N allele gives an increase in spontaneous levels of apoptosis. We suggest that the inability of XRCC3 T241M to apoptotically eliminate aberrant cells with mitotic defects could increase cancer susceptibility in individuals carrying this variant. In contrast, cells carrying the XRCC3 D213N variant are able to eliminate aberrant cells by apoptosis, and consistent with this observation, this variant does not seem to be associated with cancer susceptibility.
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Proteínas de Ligação a DNA/genética , Suscetibilidade a Doenças/metabolismo , Mitose , Neoplasias/genética , Alelos , Animais , Apoptose/genética , Células CHO , Linhagem Celular , Células Cultivadas , Centrossomo/metabolismo , Cricetinae , Proteínas de Ligação a DNA/metabolismo , Suscetibilidade a Doenças/embriologia , Imunofluorescência , Variação Genética , Humanos , Mitose/genética , Neoplasias/metabolismoRESUMO
Inherited mutations of the BRCA1 and BRCA2 genes, whose protein products are necessary for the homology-directed DNA repair pathway, confer a dominant susceptibility to cancer. We have investigated whether mutations of genes encoding other components of the same DNA repair pathway can also affect cancer susceptibility. We have identified three novel non-synonymous substitutions in one such gene, encoding the RAD51-related protein XRCC3. One of these variants, D213N, occurs in a highly conserved ATP-binding domain and completely abrogates the ability of the transfected gene to correct the phenotype of XRCC3 deficient cells. The D213N variant was found in the heterozygous state in DNA from 3/1577 healthy individuals. However, we did not detect this variant at all amongst 187 breast cancer families and 1300 unrelated patients with common cancers. Thus we have no evidence that D213N increases the risk of cancer. We propose that not all components of the homologous recombination repair complex can act as cancer susceptibility genes.
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Trifosfato de Adenosina/metabolismo , Reparo do DNA , Proteínas de Ligação a DNA/genética , Neoplasias/genética , Sequência de Aminoácidos , Sequência Conservada , Predisposição Genética para Doença , Variação Genética , Humanos , Dados de Sequência Molecular , Mutação , Recombinação Genética , Alinhamento de Sequência , TransfecçãoRESUMO
An acquired genetic instability, resulting from the loss of some types of DNA repair, is an early event in the development of a subset of human cancers. The involvement of BRCA1 and BRCA2 in the homologous recombination repair (HRR) of double-strand breaks in DNA implicates this pathway in the suppression of breast cancer. A family of proteins related to human RAD51, including XRCC2, are essential components of this repair pathway. Using site-directed mutagenesis of XRCC2, we show that non-conservative substitution or deletion of amino acid 188 of XRCC2 can significantly affect cellular sensitivity to DNA damage, and that a polymorphic variant at this site (R188H ), present on 6% of chromosomes in the population, has a weak effect on damage sensitivity. We tested the hypothesis that the R188H polymorphism could be a low-penetrance susceptibility factor for breast cancer, by genotyping 521 women with breast cancer and a total of 895 control women. Carriage of the rare allele of XRCC2 R188H was associated with breast cancer overall [odds ratio 1.3; 95% confidence interval (CI)=(1.0, 1.8)] and when younger-onset cases with a positive family history were compared with older controls with no family history [odds ratio 1.9; 95% CI=(1.0, 3.8)]. These results support the hypothesis that subtle variation in DNA repair capacity may influence cancer susceptibility in the population.