Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
1.
Oncogene ; 43(8): 608-614, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38200229

RESUMO

In this study we conducted the first investigation to assess the efficacy of a novel therapeutic antibody developed to target annexin-A1 (ANXA1). ANXA1 is an immunomodulatory protein which has been shown to be overexpressed in, and promote the development and progression of, several cancer types. In particular, high ANXA1 expression levels correlate with poorer overall survival in pancreatic and triple-negative breast cancers, two cancers with considerable unmet clinical need. MDX-124 is a humanised IgG1 monoclonal antibody which specifically binds to ANXA1 disrupting its interaction with formyl peptide receptors 1 and 2 (FPR1/2). Here we show that MDX-124 significantly reduced proliferation (p < 0.013) in a dose-dependent manner across a panel of human cancer cell lines expressing ANXA1. The anti-proliferative effect of MDX-124 is instigated by arresting cell cycle progression with cancer cells accumulating in the G1 phase of the cell cycle. Furthermore, MDX-124 significantly inhibited tumour growth in both the 4T1-luc triple-negative breast and Pan02 pancreatic cancer syngeneic mouse models (p < 0.0001). These findings suggest ANXA1-targeted therapy is a viable and innovative approach to treat tumours which overexpress ANXA1.


Assuntos
Anexina A1 , Neoplasias , Animais , Humanos , Camundongos , Anexina A1/antagonistas & inibidores , Anexina A1/metabolismo , Linhagem Celular
2.
BMJ Ment Health ; 26(1)2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37907331

RESUMO

BACKGROUND: People with severe mental illness (SMI) have a higher prevalence of several chronic physical health conditions, and the prevalence of physical multimorbidity is expected to rise. The aim of this study was to assess the strength of the association between SMI and physical multimorbidity. STUDY SELECTION AND ANALYSIS: We systematically searched PubMed/Medline, Scopus, Embase, Web of Science, PsycINFO and the behavioural sciences collection databases, from inception to 31 January 2023, for studies that investigated the association between SMI and physical multimorbidity. Humans of any age either clinically diagnosed and/or currently receiving treatment for SMI, specified as schizophrenia (and related psychotic disorders), bipolar disorder and psychotic depression, were eligible. Data from studies selected for inclusion were converted into ORs, with a subsequent meta-analysis conducted. FINDINGS: We included 19 studies with a total of 194 123 patients with SMI with different diagnoses and drawn from the general population. The pooled OR for physical multimorbidity in people with versus without SMI was 1.84 (95% CI 1.33 to 2.54), with the analysis indicating a high level of heterogeneity (98.38%). The other 15 studies included in the systematic review for which it was not possible to conduct a meta-analysis showed strong associations between SMI and physical multimorbidity. CONCLUSIONS: The current evidence highlights the link between SMI and physical multimorbidity. A multidisciplinary approach is now urgent to develop the best models of services tailored to patients with SMI with physical multimorbidities to improve physical, mental and social outcomes. PROSPERO registration number CRD42023395165.


Assuntos
Transtorno Bipolar , Transtornos Mentais , Transtornos Psicóticos , Esquizofrenia , Humanos , Multimorbidade , Transtornos Mentais/epidemiologia , Transtornos Psicóticos/epidemiologia , Doença Crônica
3.
Eat Weight Disord ; 28(1): 72, 2023 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-37676625

RESUMO

PURPOSE: People with eating disorders may be at increased risk for physical health problems, but there are no data on the relationship between eating disorders and physical multimorbidity (i.e., ≥ 2 physical conditions) and its potential mediators. Thus, we investigated this association in a representative sample of adults from the UK, and quantified the extent to which this can be explained by various psychological and physical conditions, and lifestyle factors. METHODS: Cross-sectional data of the 2007 Adult Psychiatric Morbidity Survey were analyzed. Questions from the five-item SCOFF screening instrument were used to identify possible eating disorder. Respondents were asked about 20 physical health conditions. Multivariable logistic regression and mediation analysis were conducted. RESULTS: Data on 7403 individuals aged ≥ 16 years were analyzed [mean (SD) age 46.3 (18.6) years; 48.6% males]. After adjustment, possible eating disorder was associated with 2.11 (95%CI = 1.67-2.67) times higher odds for physical multimorbidity. Anxiety disorder explained the largest proportion this association (mediated percentage 26.3%), followed by insomnia (21.8%), perceived stress (13.4%), depression (13.1%), obesity (13.0%), and alcohol dependence (4.3%). CONCLUSION: Future longitudinal studies are warranted to understand potential causality and the underlying mechanisms in the association between eating disorder and multimorbidity, and whether addressing the identified potential mediators in people with eating disorders can reduce multimorbidity.


Assuntos
Alcoolismo , Transtornos da Alimentação e da Ingestão de Alimentos , Adulto , Masculino , Humanos , Feminino , Estudos Transversais , Multimorbidade , Transtornos da Alimentação e da Ingestão de Alimentos/epidemiologia , Estilo de Vida
5.
Curr Oncol ; 30(2): 1805-1817, 2023 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-36826101

RESUMO

Depression is a common and disabling disorder in later life, particularly among people with poor physical health. There are many screening tools available that can be used to examine depressive symptoms; however, not all of them may be appropriate or accurate for older adults with cancer. This pilot study was designed to test the diagnostic performance of two screening tools and their short versions in a cohort of vulnerable (G8 score ≤ 14/17) older patients with cancer undergoing comprehensive geriatric assessment (CGA). The prospective analysis covered 50 vulnerable patients with cancer aged ≥70 years. The diagnostic performance of the Geriatric Depression Scale (GDS)-15, GDS-4, Patient Health Questionnaire (PHQ)-9 and PHQ-2 was compared to the 'gold standard' Structured Clinical Interview for DSM-5 Disorders (SCID-5-S) depression module A. The sensitivity and specificity in detecting depressive symptoms were the highest in the case of PHQ-2, with an area under the receiver operating characteristic curve (AUROC) of 92.7%. The AUROC for the 9-item version, PHQ-9, was 90.2%. For the GDS-15 and GDS-4, the AUROC was only 56.2% and 62.0%, respectively. The SCREEN pilot study illustrates the potential benefit of using a shorter screening tool, PHQ-2, to identify older patients with cancer who would benefit from a more in-depth emotional evaluation as part of a CGA.


Assuntos
Depressão , Neoplasias , Idoso , Humanos , Depressão/diagnóstico , Avaliação Geriátrica , Projetos Piloto , Detecção Precoce de Câncer
6.
Geriatrics (Basel) ; 8(1)2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36826360

RESUMO

Whilst cancer remains a very serious health problem at any stage, cancer combined with increasing age creates an even more challenging situation for health care providers [...].

7.
Cancers (Basel) ; 14(23)2022 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-36497363

RESUMO

Psychosocial oncology is coming of age [...].

8.
Microorganisms ; 10(8)2022 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-36014051

RESUMO

Recently, numerous cases of monkeypox were reported from several non-endemic countries in Europe, North America, and Oceania, suggesting an unusual and alarming public health issue, particularly considering that the disease is not directly related to human or animal travels. Attention is currently being drawn to this phenomenon since more than 70% of the global population is no longer vaccinated against smallpox. Indeed, the smallpox vaccination also confers some indirect degree of protection against other poxviruses, including monkeypox. We performed a narrative review to describe the existing literature with regard to monkeypox using the MEDLINE, EMBASE, and Scopus databases. This review aims to provide updated evidence of findings on the epidemiology, clinical features, diagnosis, management, and prevention of monkeypox, also considering the concurrent zoonotic pandemic caused by the COVID-19 coronavirus, SARS-CoV-2.

10.
J Urol ; 206(6): 1361-1372, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34288714

RESUMO

PURPOSE: Ejaculatory dysfunction (EjD) and erectile dysfunction after cancer treatment are clinically important complications, but their exact prevalence by various kinds of cancer site and type of treatment is unknown. The aim of this systematic review and meta-analysis was to examine the available evidence and provide pooled estimates for prevalence of EjD and erectile dysfunction in relation to all cancer sites and identify characteristics associated with EjD in cancer patients. MATERIALS AND METHODS: We performed a systematic review and meta-analysis of cross-sectional and case-control studies. We searched 4 electronic databases (Medline®, CINAHL, PsychInfo and Embase®) until July 22, 2020. All retrospective or prospective studies reporting the prevalence of EjD in male patients with cancer were included in this review. A random effects meta-analysis was conducted calculating prevalence proportions with 95% confidence intervals. Prevalence proportions were calculated for the incidences of EjD by cancer site and type of treatment. RESULTS: A total of 64 studies (a total of 10,057 participants) were included for analysis. The most common cancer sites were bladder, colon, testis and rectum. The prevalence rates of EjD after surgical intervention ranged from 14.5% (95% CI 2.2-56.3) in colon cancer to 53.0% (95% CI 23.3-80.7) in bladder cancer. The prevalence rates of erectile dysfunction ranged from 6.8% (95% CI 0.8-39.1) in bladder cancer to 68.7% (95% CI 55.2-79.6) in cancer of the rectum. CONCLUSIONS: In a large study-level meta-analysis, we looked at a high prevalence of EjD and erectile dysfunction at various cancer sites and across different treatment types. Prospective studies of EjD and erectile dysfunction after various kinds of cancer treatments are warranted.


Assuntos
Ejaculação , Disfunção Erétil/epidemiologia , Disfunção Erétil/etiologia , Neoplasias/complicações , Disfunções Sexuais Fisiológicas/epidemiologia , Disfunções Sexuais Fisiológicas/etiologia , Humanos , Masculino , Prevalência
11.
Br J Gen Pract ; 71(706): e372-e380, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33926885

RESUMO

BACKGROUND: Prevalence of erectile dysfunction (ED) in male survivors of cancer across cancer types has not been systematically analysed. AIM: To estimate the prevalence of ED in all types of cancer and identify characteristics associated with ED in survivors of cancer. DESIGN AND SETTING: Systematic review and meta-analysis (MA) of cross-sectional studies. METHOD: MEDLINE, CINAHL, PsycINFO, and EMBASE were searched, targeting reports published from inception to 1 February 2020. All retrospective or prospective studies reporting prevalence of ED in male patients with cancer and using a validated tool for detection of ED were included. A random-effects MA model was used to pool prevalence of ED as absolute estimates at three different stages, that is, 'healthy', 'at diagnosis', and 'after treatment'. A univariate MA regression including the three-level group variable as the only independent variable was used to assess the difference in ED prevalence across the three groups. Further MAs were conducted for studies involving patients at diagnosis and after treatment, and statistical inferences were made with setting for multiple testing controlling for a false discovery rate (FDR) <0.05. RESULTS: In total, 1301 studies were assessed for inclusion. Of these, 141 were potentially eligible and subsequently scrutinised in full text. Finally, 43 studies were included with a total of 13 148 participants. Overall, pooled data of the included studies showed an ED prevalence of 40.72% (95% confidence interval [CI] = 31.80 to 50.29) in patients with cancer, with prevalences of 28.60% (95% CI = 12.10 to 53.83) at time of diagnosis and 42.70% (95% CI = 32.97 to 53.03) after treatment, with significant difference between these two stages and across cancer locations, controlling for an FDR <0.05. CONCLUSION: Erectile dysfunction was particularly high in male survivors of cancer and was associated with cancer treatment, cancer site, and age.


Assuntos
Disfunção Erétil , Neoplasias , Estudos Transversais , Disfunção Erétil/epidemiologia , Disfunção Erétil/etiologia , Humanos , Masculino , Prevalência , Estudos Prospectivos , Estudos Retrospectivos , Sobreviventes
12.
Clin Exp Med ; 20(3): 409-416, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32219665

RESUMO

The objective of the present study was to investigate the association between angiotensin-converting enzyme (ACE) inhibitor use and cancer incidence (overall, and breast, prostate, and colorectal cancers specifically) in a large representative sample of US adults. Cross-sectional data on cancer diagnosis, timing of cancer diagnosis, ACE inhibitor use, and other characteristics were extracted from 49 512 adults aged ≥ 20 years participating in the National Health and Nutrition Examination Survey (1999-2016). Multivariable-logistic and propensity score matching (PSM) regressions examined the relationship between pre-diagnosis use of ACE inhibitors and diagnosis of all cancers, and breast, prostate, and colorectal cancers specifically. Overall, we observed an increased likelihood of cancer diagnosis [odds ratio (OR) 1.269, 95% confidence interval (CI) 1.088-1.480] among those who used ACE inhibitors compared to non-ACE inhibitor use, and for prostate cancer diagnosis (OR 1.438, 95% CI 1.090-1.897), after adjusting for age, sex, body mass index, race/ethnicity, educational attainment, physical activity, alcohol drinking status, smoking status, and high blood pressure. PSM regression retrieved more conservative estimates such that the increased likelihood of cancer diagnosis was only observed when comparing ACE inhibitor users with non-drug users (OR 1.022, 95% CI 1.016-1.027). Compared with non-ACE inhibitor use, ACE inhibitor use was associated with an increased risk of prostate cancer. In conclusion, in this large representative sample of US adults, it was found that ACE inhibitor use may have a marginal influence on some cancers.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/efeitos adversos , Neoplasias da Mama/epidemiologia , Neoplasias Colorretais/epidemiologia , Neoplasias da Próstata/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/induzido quimicamente , Neoplasias Colorretais/induzido quimicamente , Estudos Transversais , Feminino , Humanos , Incidência , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/induzido quimicamente , Fatores de Risco , Inquéritos e Questionários , Estados Unidos/epidemiologia
13.
Cancers (Basel) ; 11(8)2019 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-31405192

RESUMO

Liquid biopsy (LB) is a non-invasive approach representing a promising tool for new precision medicine strategies for cancer treatment. However, a comprehensive analysis of its reliability for pancreatic cancer (PC) is lacking. To this aim, we performed the first meta-analysis on this topic. We calculated the pooled sensitivity, specificity, positive (LR+) and negative (LR-) likelihood ratio, and diagnostic odds ratio (DOR). A summary receiver operating characteristic curve (SROC) and area under curve (AUC) were used to evaluate the overall accuracy. We finally assessed the concordance rate of all mutations detected by multi-genes panels. Fourteen eligible studies involving 369 patients were included. The overall pooled sensitivity and specificity were 0.70 and 0.86, respectively. The LR+ was 3.85, the LR- was 0.34 and DOR was 15.84. The SROC curve with an AUC of 0.88 indicated a relatively high accuracy of LB for molecular characterization of PC. The concordance rate of all mutations detected by multi-genes panels was 31.9%. LB can serve as surrogate for tissue in the molecular profiling of PC, because of its relatively high sensitivity, specificity and accuracy. It represents a unique opportunity to be further explored towards its introduction in clinical practice and for developing new precision medicine approaches against PC.

14.
J Cancer ; 8(19): 4048-4056, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29187880

RESUMO

The use of polyADPribose polymerase inhibitors in cancer treatment provides a unique opportunity to target DNA repair processes in cancer cells while leaving normal tissue intact. The PARP-1 enzyme repairs DNA single strand breaks (SSB). Therefore PARP-1 inhibition in BRCA1 negative cancers results in the formation of cytotoxic DNA double strand breaks (DSB) causing synthetic lethality. The use of PARP1 inhibitors is gaining momentum in the treatment of a variety of tumours with BRCA1 involvement including breast, ovarian, pancreatic and prostate cancer. Our previous work showed that the PARP-1 inhibitor Olaparib causes both hypersensitivity of BRCA1+/- cells following exposure to gamma radiation due to the persistence of DNA strand breaks in cells, measured by the DNA damage biomarker γ-H2AX. Therefore dual treatment of cancers with radiotherapy and PARP1 inhibition may lead to cases of increased normal tissue toxicity in cancer patients. In this study we exposed two normal lymphoblastoid cell lines and three heterozygous BRCA1 lymphoblastoid cell lines to the PARP-1 inhibitor Olaparib and gamma radiation and after measured BRCA1 protein expression and apoptosis levels following treatment. BRCA1 protein foci analysis was performed on cells exposed to 2 Gy radiation in the presence or absence of 5 µM Olaparib. Using immunofluorescence and imaging flow cytometry, foci were measured in untreated cells and at 0.5, 3, 5 and 24 hours post-irradiation. Exposing normal and BRCA1+/- cells to Olaparib followed by gamma radiation results in a dramatic change in BRCA1 protein foci expression, with a significant reduction in BRCA1 protein expression observed in the heterozygote cells, together with an increase in apoptosis levels in these cells. In conclusion, combining PARP1 inhibitors with radiotherapy in treating of BRCA1-related cancers has clinical relevance, however this study and our previous publications serve to highlight the potential problems of increased side effects in these scenarios.

15.
Am J Physiol Heart Circ Physiol ; 311(5): H1297-H1310, 2016 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-27638881

RESUMO

The effect of endurance exercise on circulating microvesicle dynamics and their impact on surrounding endothelial cells is unclear. Here we tested the hypothesis that exercise intensity modulates the time course of platelet (PMV) and endothelial-derived (EMV) microvesicle appearance in the circulation through hemodynamic and biochemical-related mechanisms, and that microvesicles formed during exercise would stimulate endothelial angiogenesis in vitro. Nine healthy young men had venous blood samples taken before, during, and throughout the recovery period after 1 h of moderate [46 ± 2% maximal oxygen uptake (V̇o2max)] or heavy (67 ± 2% V̇o2max) intensity semirecumbent cycling and a time-matched resting control trial. In vitro experiments were performed by incubating endothelial cells with rest and exercise-derived microvesicles to examine their effects on cell angiogenic capacities. PMVs (CD41+) increased from baseline only during heavy exercise (from 21 ± 1 × 103 to 55 ± 8 × 103 and 48 ± 6 × 103 PMV/µl at 30 and 60 min, respectively; P < 0.05), returning to baseline early in postexercise recovery (P > 0.05), whereas EMVs (CD62E+) were unchanged (P > 0.05). PMVs were related to brachial artery shear rate (r2 = 0.43) and plasma norepinephrine concentrations (r2 = 0.21) during exercise (P < 0.05). Exercise-derived microvesicles enhanced endothelial proliferation, migration, and tubule formation compared with rest microvesicles (P < 0.05). These results demonstrate substantial increases in circulating PMVs during heavy exercise and that exercise-derived microvesicles stimulate human endothelial cells by enhancing angiogenesis and proliferation. This involvement of microvesicles may be considered a novel mechanism through which exercise mediates vascular healing and adaptation.


Assuntos
Plaquetas/fisiologia , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Micropartículas Derivadas de Células/fisiologia , Células Endoteliais/fisiologia , Exercício Físico/fisiologia , Neovascularização Fisiológica/fisiologia , Adulto , Artéria Braquial , Voluntários Saudáveis , Humanos , Técnicas In Vitro , Masculino , Norepinefrina/sangue , Consumo de Oxigênio , Resistência Física , Descanso/fisiologia , Adulto Jovem
16.
Cytometry A ; 87(8): 717-23, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26087127

RESUMO

Accurate and rapid methods for the detection of DNA damage foci in eukaryotic cells are central to DNA repair studies, which identify differences in DNA repair capacity in cell lines. Such assays have been important in delineating mechanisms of DNA repair in human cells. Previously we were the first to demonstrate the use of imaging flow cytometry for the detection of γ-H2AX foci in cells exposed to ionizing radiation causing the induction of DNA strand breaks. In this report we extend these studies and show an enhancement of foci quantitation and image resolution using next generation imaging flow cytometry with the Amnis Imagestream(X) Mark II. We demonstrate using cell lines derived from normal individuals, and DNA double strand break repair defective cells that the number of foci observed is significantly increased when using 60× as compared to 40× magnification. Also, foci numbers and resolution is further increased with the application of the focus stacking (Extended Depth of Field-EDF) capacity activated. This report represents the first such demonstration of multimagnification and EDF for the enhanced quantitation of DNA damage in cells and provides a level of resolution, which near matches in situ microscopy methods for the detection of γ-H2AX foci.


Assuntos
Dano ao DNA/genética , Histonas/genética , Linhagem Celular , Quebras de DNA de Cadeia Dupla/efeitos da radiação , Reparo do DNA/genética , Citometria de Fluxo/métodos , Humanos , Citometria por Imagem/métodos , Radiação Ionizante
17.
Chemotherapy ; 60(5-6): 310-20, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-26138778

RESUMO

Chemotherapeutic anticancer drugs mediate cytotoxicity by a number of mechanisms. However, alkylating agents which induce DNA interstrand crosslinks (ICL) are amongst the most effective anticancer agents and often form the mainstay of many anticancer therapies. The effectiveness of these drugs can be limited by the development of drug resistance in cancer cells and many studies have demonstrated that alterations in DNA repair kinetics are responsible for drug resistance. In this study we developed two cell lines resistant to the alkylating agents nitrogen mustard (HN2) and cisplatin (Pt). To determine if drug resistance was associated with enhanced ICL DNA repair we used immunocytochemistry and imaging flow cytometry to quantitate the number of γ-H2AX and Rad51 foci in the nuclei of cells after drug exposure. γ-H2AX was used to evaluate DNA strand breaks caused by repair incision nucleases and Rad51 was used to measure the activity of homologous recombination in the repair of ICL. In the drug-resistant derivative cell lines there was overall a significant increase in the number and persistence of both γ-H2AX and Rad51 foci in the nuclei of cells over a 72-hour period, when compared to the non-resistant parental cell lines (ANOVA p < 0.0001). In a Pt-resistant ovarian cancer cell line (A2780cis(R)) a similar enhancement of DNA repair was observed when compared to the non-drug-resistant wild-type ovarian cancer cells (A2780) following exposure to HN2. Our data suggest that using DNA repair biomarkers to evaluate mechanisms of resistance in cancer cell lines and human tumours may be of experimental and clinical benefit. We concede, however, that examination of a larger population of cell lines and tumours is required to fully evaluate the validity of this approach.


Assuntos
Cisplatino/farmacologia , Reparo do DNA/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Histonas/biossíntese , Mecloretamina/farmacologia , Rad51 Recombinase/biossíntese , Antineoplásicos/farmacologia , Biomarcadores Tumorais/biossíntese , Biomarcadores Tumorais/genética , Linhagem Celular Transformada , Linhagem Celular Tumoral , Reparo do DNA/fisiologia , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos/fisiologia , Regulação Neoplásica da Expressão Gênica , Histonas/genética , Humanos , Rad51 Recombinase/genética
18.
Cytometry A ; 81(2): 130-7, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22170789

RESUMO

The measurement of γ-H2AX foci induction in cells provides a sensitive and reliable method for the quantitation of DNA damage responses in a variety of cell types. Accurate and rapid methods to conduct such observations are desirable. In this study, we have employed the novel technique of multispectral imaging flow cytometry to compare the induction and repair of γ-H2AX foci in three human cell types with different capacities for the repair of DNA double strand breaks (DSB). A repair normal fibroblast cell line MRC5-SV1, a DSB repair defective ataxia telangiectasia (AT5BIVA) cell line, and a DNA-PKcs deficient cell line XP14BRneo17 were exposed to 2 Gy gamma radiation from a (60)Cobalt source. Thirty minutes following exposure, we observed a dramatic induction of foci in the nuclei of these cells. After 24 hrs, there was a predictable reduction on the number of foci in the MRC5-SV1 cells, consistent with the repair of DNA DSB. In the AT5BIVA cells, persistence of the foci over a 24-hr period was due to the failure in the repair of DNA DSB. However, in the DNA-PKcs defective cells (XP14BRneo17), we observed an intermediate retention of foci in the nuclei indicative of partial repair of DNA DSB. In summary, the application of imaging flow cytometry has permitted an evaluation of foci in a large number of cells (20,000) for each cell line at each time point. This provides a novel method to determine differences in repair kinetics between different cell types. We propose that imaging flow cytometry provides an alternative platform for accurate automated high through-put analysis of foci induction in a variety of cell types.


Assuntos
Quebras de DNA de Cadeia Dupla , Reparo do DNA , Citometria de Fluxo/métodos , Histonas/metabolismo , Citometria por Imagem/métodos , Linhagem Celular , Núcleo Celular/metabolismo , Núcleo Celular/efeitos da radiação , Quebras de DNA de Cadeia Dupla/efeitos da radiação , Reparo do DNA/efeitos da radiação , Relação Dose-Resposta à Radiação , Fluorescência , Raios gama , Humanos
19.
Int J Cancer ; 129(12): 2928-34, 2011 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-21491423

RESUMO

The normal tissue tolerance levels to fractionated radiotherapy have been appreciated by a century of careful clinical observations and radiobiological studies in animals. During clinical fractionated radiotherapy, these normal tissue tolerance levels are respected, and severe sequelae of radiotherapy are avoided in the majority of patients. Notwithstanding, a minority of patients experience unexpectedly severe normal tissue reactions. The ability to predict which patients might form this minority would be important. We have conducted a study to develop a rapid and reliable diagnostic test to predict excessive normal tissue toxicity (NTT) in radiotherapy patients. A flow cytometric immunocytochemical assay was used to measure DNA damage in peripheral blood lymphocytes (PBL) from cancer patients exposed to 2-Gy gamma radiation. DNA damage and repair was measured by induction of cellular γ-H2AX in unirradiated and exposed cells at specific time points following exposure. In 12 cancer patients that experienced severe atypical NTT following radiotherapy, there was a failure to repair DNA double-strand breaks (DSB) as measured by γ-H2AX induction and persistence. In ten cancer patients that experienced little or no NTT and in seven normal (noncancer controls), efficient repair of DNA DSB was observed in the γ-H2AX assay. We conclude that a flow cytometric assay based on γ-H2AX induction in PBL of radiotherapy patients may represent a robust, rapid and reliable biomarker to predict NTT during radiotherapy. Further research is required with a larger patient cohort to validate this important study.


Assuntos
Histonas/metabolismo , Radioterapia/efeitos adversos , Adulto , Biomarcadores/metabolismo , Quebras de DNA de Cadeia Dupla , Dano ao DNA , Reparo do DNA , Relação Dose-Resposta à Radiação , Feminino , Raios gama , Humanos , Linfócitos/efeitos da radiação , Masculino , Pessoa de Meia-Idade
20.
J Med Genet ; 47(3): 176-81, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19797196

RESUMO

BACKGROUND: Radiotherapy-induced DNA double-strand breaks (DSBs) are critical cytotoxic lesions. Inherited defects in DNA DSB repair pathways lead to hypersensitivity to ionising radiation, immunodeficiency and increased cancer incidence. A patient with xeroderma pigmentosum complementation group C, with a scalp angiosarcoma, exhibited dramatic clinical radiosensitivity following radiotherapy, resulting in death. A fibroblast cell line from non-affected skin (XP14BRneo17) was hypersensitive to ionising radiation and defective in DNA DSB repair. AIM: To determine the genetic defect causing cellular radiation hypersensitivity in XP14BRneo17 cells. METHODS: Functional genetic complementation whereby copies of human chromosomes containing genes involved in DNA DSB repair (chromosomes 2, 5, 8 10, 13 and 22) were individually transferred to XP14BRneo17 cells in an attempt to correct the radiation hypersensitivity. Clonogenic survival assays and gamma-H2AX immunofluorescence were conducted to measure radiation sensitivity and repair of DNA DSBs. DNA sequencing of defective DNA repair genes was performed. RESULTS: Transfer of chromosome 8 (location of DNA-PKcs gene) and transfection of a mammalian expression construct containing the DNA-PKcs cDNA restored normal ionising radiation sensitivity and repair of DNA DSBs in XP14BRneo17 cells. DNA sequencing of the DNA-PKcs coding region revealed a 249-bp deletion (between base pairs 3656 and 3904) encompassing exon 31 of the gene. CONCLUSION: We provide evidence of a novel splice variant of the DNA-PKcs gene associated with radiosensitivity in a patient with xeroderma pigmentosum and report the first double mutant in distinct DNA repair pathways being consistent with viability.


Assuntos
Proteína Quinase Ativada por DNA/fisiologia , Neoplasias de Cabeça e Pescoço/radioterapia , Hemangiossarcoma/radioterapia , Proteínas Nucleares/fisiologia , Tolerância a Radiação/genética , Neoplasias Cutâneas/radioterapia , Xeroderma Pigmentoso/genética , Processamento Alternativo/fisiologia , Sequência de Aminoácidos , Sobrevivência Celular/genética , Sobrevivência Celular/efeitos da radiação , Células Cultivadas , Proteína Quinase Ativada por DNA/genética , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/patologia , Hemangiossarcoma/genética , Hemangiossarcoma/patologia , Humanos , Isoenzimas/genética , Isoenzimas/fisiologia , Dados de Sequência Molecular , Proteínas Nucleares/genética , Isoformas de Proteínas/genética , Isoformas de Proteínas/fisiologia , Lesões por Radiação/genética , Couro Cabeludo , Homologia de Sequência de Aminoácidos , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Xeroderma Pigmentoso/patologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...