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1.
Am J Hum Genet ; 110(3): 475-486, 2023 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-36827971

RESUMO

Evidence linking coding germline variants in breast cancer (BC)-susceptibility genes other than BRCA1, BRCA2, and CHEK2 with contralateral breast cancer (CBC) risk and breast cancer-specific survival (BCSS) is scarce. The aim of this study was to assess the association of protein-truncating variants (PTVs) and rare missense variants (MSVs) in nine known (ATM, BARD1, BRCA1, BRCA2, CHEK2, PALB2, RAD51C, RAD51D, and TP53) and 25 suspected BC-susceptibility genes with CBC risk and BCSS. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated with Cox regression models. Analyses included 34,401 women of European ancestry diagnosed with BC, including 676 CBCs and 3,449 BC deaths; the median follow-up was 10.9 years. Subtype analyses were based on estrogen receptor (ER) status of the first BC. Combined PTVs and pathogenic/likely pathogenic MSVs in BRCA1, BRCA2, and TP53 and PTVs in CHEK2 and PALB2 were associated with increased CBC risk [HRs (95% CIs): 2.88 (1.70-4.87), 2.31 (1.39-3.85), 8.29 (2.53-27.21), 2.25 (1.55-3.27), and 2.67 (1.33-5.35), respectively]. The strongest evidence of association with BCSS was for PTVs and pathogenic/likely pathogenic MSVs in BRCA2 (ER-positive BC) and TP53 and PTVs in CHEK2 [HRs (95% CIs): 1.53 (1.13-2.07), 2.08 (0.95-4.57), and 1.39 (1.13-1.72), respectively, after adjusting for tumor characteristics and treatment]. HRs were essentially unchanged when censoring for CBC, suggesting that these associations are not completely explained by increased CBC risk, tumor characteristics, or treatment. There was limited evidence of associations of PTVs and/or rare MSVs with CBC risk or BCSS for the 25 suspected BC genes. The CBC findings are relevant to treatment decisions, follow-up, and screening after BC diagnosis.


Assuntos
Neoplasias da Mama , Feminino , Humanos , Neoplasias da Mama/genética , Genes BRCA2 , Mutação em Linhagem Germinativa , Células Germinativas , Predisposição Genética para Doença
2.
Am J Hum Genet ; 109(10): 1777-1788, 2022 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-36206742

RESUMO

Rare pathogenic variants in known breast cancer-susceptibility genes and known common susceptibility variants do not fully explain the familial aggregation of breast cancer. To investigate plausible genetic models for the residual familial aggregation, we studied 17,425 families ascertained through population-based probands, 86% of whom were screened for pathogenic variants in BRCA1, BRCA2, PALB2, CHEK2, ATM, and TP53 via gene-panel sequencing. We conducted complex segregation analyses and fitted genetic models in which breast cancer incidence depended on the effects of known susceptibility genes and other unidentified major genes and a normally distributed polygenic component. The proportion of familial variance explained by the six genes was 46% at age 20-29 years and decreased steadily with age thereafter. After allowing for these genes, the best fitting model for the residual familial variance included a recessive risk component with a combined genotype frequency of 1.7% (95% CI: 0.3%-5.4%) and a penetrance to age 80 years of 69% (95% CI: 38%-95%) for homozygotes, which may reflect the combined effects of multiple variants acting in a recessive manner, and a polygenic variance of 1.27 (95% CI: 0.94%-1.65), which did not vary with age. The proportion of the residual familial variance explained by the recessive risk component was 40% at age 20-29 years and decreased with age thereafter. The model predicted age-specific familial relative risks consistent with those observed by large epidemiological studies. The findings have implications for strategies to identify new breast cancer-susceptibility genes and improve disease-risk prediction, especially at a young age.


Assuntos
Neoplasias da Mama , Predisposição Genética para Doença , Adulto , Idoso de 80 Anos ou mais , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/genética , Estudos de Casos e Controles , Feminino , Humanos , Herança Multifatorial/genética , Penetrância , Adulto Jovem
3.
N Engl J Med ; 384(5): 428-439, 2021 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-33471991

RESUMO

BACKGROUND: Genetic testing for breast cancer susceptibility is widely used, but for many genes, evidence of an association with breast cancer is weak, underlying risk estimates are imprecise, and reliable subtype-specific risk estimates are lacking. METHODS: We used a panel of 34 putative susceptibility genes to perform sequencing on samples from 60,466 women with breast cancer and 53,461 controls. In separate analyses for protein-truncating variants and rare missense variants in these genes, we estimated odds ratios for breast cancer overall and tumor subtypes. We evaluated missense-variant associations according to domain and classification of pathogenicity. RESULTS: Protein-truncating variants in 5 genes (ATM, BRCA1, BRCA2, CHEK2, and PALB2) were associated with a risk of breast cancer overall with a P value of less than 0.0001. Protein-truncating variants in 4 other genes (BARD1, RAD51C, RAD51D, and TP53) were associated with a risk of breast cancer overall with a P value of less than 0.05 and a Bayesian false-discovery probability of less than 0.05. For protein-truncating variants in 19 of the remaining 25 genes, the upper limit of the 95% confidence interval of the odds ratio for breast cancer overall was less than 2.0. For protein-truncating variants in ATM and CHEK2, odds ratios were higher for estrogen receptor (ER)-positive disease than for ER-negative disease; for protein-truncating variants in BARD1, BRCA1, BRCA2, PALB2, RAD51C, and RAD51D, odds ratios were higher for ER-negative disease than for ER-positive disease. Rare missense variants (in aggregate) in ATM, CHEK2, and TP53 were associated with a risk of breast cancer overall with a P value of less than 0.001. For BRCA1, BRCA2, and TP53, missense variants (in aggregate) that would be classified as pathogenic according to standard criteria were associated with a risk of breast cancer overall, with the risk being similar to that of protein-truncating variants. CONCLUSIONS: The results of this study define the genes that are most clinically useful for inclusion on panels for the prediction of breast cancer risk, as well as provide estimates of the risks associated with protein-truncating variants, to guide genetic counseling. (Funded by European Union Horizon 2020 programs and others.).


Assuntos
Neoplasias da Mama/genética , Predisposição Genética para Doença/genética , Variação Genética , Mutação de Sentido Incorreto , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Modelos Logísticos , Pessoa de Meia-Idade , Razão de Chances , Risco , Análise de Sequência de DNA , Adulto Jovem
4.
Int J Mol Sci ; 25(5)2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38473998

RESUMO

Interferon alpha-2b (IFN-α2b) is an essential cytokine widely used in the treatment of chronic hepatitis C and hairy cell leukemia, and serum albumin is the most abundant plasma protein with numerous physiological functions. Effective single-step aqueous biphasic system (ABS) extraction for the simultaneous purification of IFN-α2b and BSA (serum albumin protein) was developed in this work. Effects of the ionic liquid (IL)-based ABS functionalization, fluorinated ILs (FILs; [C​2C​1Im][C​4F​9SO​3] and [N​1112(OH)][C​4F​9SO​3]) vs. mere fluoro-containing IL ([C​4C​1Im][CF​3SO​3]), in combination with sucrose or [N​1112(OH)][H​2PO​4] (well-known globular protein stabilizers), or high-charge-density salt K​3PO​4 were investigated. The effects of phase pH, phase water content (%wt), phase composition (%wt), and phase volume ratio were investigated. The phase pH was found to have a significant effect on IFN-α2b and BSA partition. Experimental results show that simultaneous single-step purification was achieved with a high yield (extraction efficiency up to 100%) for both proteins and a purification factor of IFN-α2b high in the enriched IFN-α2b phase (up to 23.22) and low in the BSA-enriched phase (down to 0.00). SDS-PAGE analysis confirmed the purity of both recovered proteins. The stability and structure of IFN-α2b and BSA were preserved or even improved (FIL-rich phase) during the purification step, as evaluated by CD spectroscopy and DSC. Binding studies of IFN-α2b and BSA with the ABS phase-forming components were assessed by MST, showing the strong interaction between FILs aggregates and both proteins. In view of their biocompatibility, customizable properties, and selectivity, FIL-based ABSs are suggested as an improved purification step that could facilitate the development of biologics.


Assuntos
Líquidos Iônicos , Albumina Sérica , Humanos , Albumina Sérica/química , Líquidos Iônicos/química , Interferon-alfa/farmacologia , Água/química , Proteínas Recombinantes
5.
Int J Mol Sci ; 25(11)2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38891953

RESUMO

This work unfolds functionalized ABSs composed of FILs ([C2C1Im][C4F9SO3] and [N1112(OH)][C4F9SO3]), mere fluoro-containing ILs ([C2C1Im][CF3SO3] and [C4C1Im][CF3SO3]), known globular protein stabilizers (sucrose and [N1112(OH)][C4F9SO3]), low-molecular-weight carbohydrate (glucose), and even high-charge density salt (K3PO4). The ternary phase diagrams were determined, stressing that FILs highly increased the ability for ABS formation. The functionalized ABSs (FILs vs. mere fluoro-containing ILs) were used to extract lysozyme (Lys). The ABSs' biphasic regions were screened in terms of protein biocompatibility, analyzing the impact of ABS phase-forming components in Lys by UV-VIS spectrophotometry, CD spectroscopy, fluorescence spectroscopy, DSC, and enzyme assay. Lys partition behavior was characterized in terms of extraction efficiency (% EE). The structure, stability, and function of Lys were maintained or improved throughout the extraction step, as evaluated by CD spectroscopy, DSC, enzyme assay, and SDS-PAGE. Overall, FIL-based ABSs are more versatile and amenable to being tuned by the adequate choice of the phase-forming components and selecting the enriched phase. Binding studies between Lys and ABS phase-forming components were attained by MST, demonstrating the strong interaction between Lys and FILs aggregates. Two of the FIL-based ABSs (30 %wt [C2C1Im][C4F9SO3] + 2 %wt K3PO4 and 30 %wt [C2C1Im][C4F9SO3] + 25 %wt sucrose) allowed the simultaneous purification of Lys and BSA in a single ABS extraction step with high yield (extraction efficiency up to 100%) for both proteins. The purity of both recovered proteins was validated by SDS-PAGE analysis. Even with a high-charge density salt, the FIL-based ABSs developed in this work seem more amenable to be tuned. Lys and BSA were purified through selective partition to opposite phases in a single FIL-based ABS extraction step. FIL-based ABSs are proposed as an improved extraction step for proteins, based on their biocompatibility, customizable properties, and selectivity.


Assuntos
Líquidos Iônicos , Muramidase , Líquidos Iônicos/química , Muramidase/química , Muramidase/isolamento & purificação , Muramidase/metabolismo , Halogenação , Água/química , Proteínas/química , Proteínas/isolamento & purificação , Animais
6.
J Pathol ; 258(4): 382-394, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36073856

RESUMO

PTEN is one of the most commonly inactivated tumour suppressor genes in sporadic cancer. Germline heterozygous PTEN gene alterations also underlie PTEN hamartoma tumour syndrome (PHTS), a rare human cancer-predisposition condition. A key feature of systemic PTEN deregulation is the inability to adequately dampen PI3-kinase (PI3K)/mTORC1 signalling. PI3K/mTORC1 pathway inhibitors such as rapamycin are therefore expected to neutralise the impact of PTEN loss, rendering this a more druggable context compared with those of other tumour suppressor pathways such as loss of TP53. However, this has not been explored in cancer prevention in a model of germline cancer predisposition, such as PHTS. Clinical trials of short-term treatment with rapamycin have recently been initiated for PHTS, focusing on cognition and colon polyposis. Here, we administered a low dose of rapamycin from the age of 6 weeks onwards to mice with heterozygous germline Pten loss, a mouse model that recapitulates most characteristics of human PHTS. Rapamycin was well tolerated and led to a highly significant improvement of survival in both male and female mice. This was accompanied by a delay in, but not full blockade of, the development of a range of proliferative lesions, including gastro-intestinal and thyroid tumours and endometrial hyperplasia, with no impact on mammary and prostate tumours, and no effect on brain overgrowth. Our data indicate that rapamycin may have cancer prevention potential in human PHTS. This might also be the case for sporadic cancers in which genetic PI3K pathway activation is an early event in tumour development, such as endometrial cancer and some breast cancers. To the best of our knowledge, this is the first report of a long-term treatment of a germline cancer predisposition model with a PI3K/mTOR pathway inhibitor. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.


Assuntos
Síndrome do Hamartoma Múltiplo , Neoplasias da Glândula Tireoide , Camundongos , Animais , Masculino , Feminino , Humanos , Lactente , Sirolimo/farmacologia , Sirolimo/uso terapêutico , Fosfatidilinositol 3-Quinases/genética , Longevidade , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Síndrome do Hamartoma Múltiplo/tratamento farmacológico , Síndrome do Hamartoma Múltiplo/genética , Síndrome do Hamartoma Múltiplo/patologia , Fosfatidilinositol 3-Quinase/genética , Inibidores de Fosfoinositídeo-3 Quinase , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Células Germinativas/metabolismo , Mutação em Linhagem Germinativa
7.
J Pathol ; 256(3): 321-334, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34846068

RESUMO

PALB2 loss-of-function variants confer high risk of developing breast cancer. Here we present a systematic functional analysis of PALB2 splice-site variants detected in approximately 113,000 women in the large-scale sequencing project Breast Cancer After Diagnostic Gene Sequencing (BRIDGES; https://bridges-research.eu/). Eighty-two PALB2 variants at the intron-exon boundaries were analyzed with MaxEntScan. Forty-two variants were selected for the subsequent splicing functional assays. For this purpose, three splicing reporter minigenes comprising exons 1-12 were constructed. The 42 potential spliceogenic variants were introduced into the minigenes by site-directed mutagenesis and assayed in MCF-7/MDA-MB-231 cells. Splicing anomalies were observed in 35 variants, 23 of which showed no traces or minimal amounts of the expected full-length transcripts of each minigene. More than 30 different variant-induced transcripts were characterized, 23 of which were predicted to truncate the PALB2 protein. The pathogenicity of all variants was interpreted according to an in-house adaptation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG-AMP) variant classification scheme. Up to 23 variants were classified as pathogenic/likely pathogenic. Remarkably, three ±1,2 variants (c.49-2A>T, c.108+2T>C, and c.211+1G>A) were classified as variants of unknown significance, as they produced significant amounts of either in-frame transcripts of unknown impact on the PALB2 protein function or the minigene full-length transcripts. In conclusion, we have significantly contributed to the ongoing effort of identifying spliceogenic variants in the clinically relevant PALB2 cancer susceptibility gene. Moreover, we suggest some approaches to classify the findings in accordance with the ACMG-AMP rationale. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd on behalf of The Pathological Society of Great Britain and Ireland.


Assuntos
Processamento Alternativo , Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Proteína do Grupo de Complementação N da Anemia de Fanconi/genética , Sítios de Splice de RNA , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Estudos de Casos e Controles , Bases de Dados Genéticas , Éxons , Proteína do Grupo de Complementação N da Anemia de Fanconi/metabolismo , Feminino , Humanos , Células MCF-7 , Isoformas de Proteínas
8.
J Med Genet ; 59(12): 1196-1205, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36162852

RESUMO

BACKGROUND: The multifactorial Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm (BOADICEA) breast cancer risk prediction model has been recently extended to consider all established breast cancer risk factors. We assessed the clinical validity of the model in a large independent prospective cohort. METHODS: We validated BOADICEA (V.6) in the Swedish KARolinska Mammography Project for Risk Prediction of Breast Cancer (KARMA) cohort including 66 415 women of European ancestry (median age 54 years, IQR 45-63; 816 incident breast cancers) without previous cancer diagnosis. We calculated 5-year risks on the basis of questionnaire-based risk factors, pedigree-structured first-degree family history, mammographic density (BI-RADS), a validated breast cancer polygenic risk score (PRS) based on 313-SNPs, and pathogenic variant status in 8 breast cancer susceptibility genes: BRCA1, BRCA2, PALB2, CHEK2, ATM, RAD51C, RAD51D and BARD1. Calibration was assessed by comparing observed and expected risks in deciles of predicted risk and the calibration slope. The discriminatory ability was assessed using the area under the curve (AUC). RESULTS: Among the individual model components, the PRS contributed most to breast cancer risk stratification. BOADICEA was well calibrated in predicting the risks for low-risk and high-risk women when all, or subsets of risk factors are included in the risk prediction. Discrimination was maximised when all risk factors are considered (AUC=0.70, 95% CI: 0.66 to 0.73; expected-to-observed ratio=0.88, 95% CI: 0.75 to 1.04; calibration slope=0.97, 95% CI: 0.95 to 0.99). The full multifactorial model classified 3.6% women as high risk (5-year risk ≥3%) and 11.1% as very low risk (5-year risk <0.33%). CONCLUSION: The multifactorial BOADICEA model provides valid breast cancer risk predictions and a basis for personalised decision-making on disease prevention and screening.


Assuntos
Neoplasias da Mama , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/genética , Genes BRCA2 , Predisposição Genética para Doença , Estudos Prospectivos , Medição de Risco
9.
J Med Genet ; 59(5): 481-491, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-33811135

RESUMO

BACKGROUND: Rare protein-truncating variants (PTVs) in partner and localiser of BRCA2 (PALB2) confer increased risk to breast cancer, but relatively few studies have reported the prevalence in South-East Asian populations. Here, we describe the prevalence of rare variants in PALB2 in a population-based study of 7840 breast cancer cases and 7928 healthy Chinese, Malay and Indian women from Malaysia and Singapore, and describe the functional impact of germline missense variants identified in this population. METHODS: Mutation testing was performed on germline DNA (n=15 768) using targeted sequencing panels. The functional impact of missense variants was tested in mouse embryonic stem cell based functional assays. RESULTS: PTVs in PALB2 were found in 0.73% of breast cancer patients and 0.14% of healthy individuals (OR=5.44; 95% CI 2.85 to 10.39, p<0.0001). In contrast, rare missense variants in PALB2 were not associated with increased risk of breast cancer. Whereas PTVs were associated with later stage of presentation and higher-grade tumours, no significant association was observed with missense variants in PALB2. However, two novel rare missense variants (p.L1027R and p.G1043V) produced unstable proteins and resulted in a decrease in homologous recombination-mediated repair of DNA double-strand breaks. CONCLUSION: Despite genetic and lifestyle differences between Asian and other populations, the population prevalence of PALB2 PTVs and associated relative risk of breast cancer, are similar to those reported in European populations.


Assuntos
Neoplasias da Mama , Predisposição Genética para Doença , Animais , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Proteína do Grupo de Complementação N da Anemia de Fanconi/genética , Feminino , Mutação em Linhagem Germinativa , Humanos , Malásia/epidemiologia , Masculino , Camundongos , Singapura/epidemiologia
10.
Ophthalmic Res ; 2022 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-36170808

RESUMO

INTRODUCTION: To characterize the two-year progression of risk phenotypes of nonproliferative diabetic retinopathy (NPDR) in type 2 diabetes (T2D) Phenotype C, or ischemic phenotype, identified by decreased skeletonized retinal vessel density (VD), ≥ 2 SD over normal values, and Phenotype B, or edema phenotype, identified by increased retinal thickness, i.e. subclinical macular edema, and no significant decrease in VD. METHODS: A prospective longitudinal cohort study (CORDIS, NCT03696810) was conducted with 4 visits (baseline, 6-months, one-year and two-year). Ophthalmological examinations included best corrected visual acuity, color fundus photography (CFP) and optical coherence tomography (OCT) and OCT Angiography. Early Treatment Diabetic Retinopathy Study grading was performed at the baseline and last visits based on 7-fields CFP. RESULTS: One hundred and twenty-two eyes from T2D individuals with NPDR fitted in the categories of phenotype B and C and completed the two-years follow-up. Sixty-five (53%) of the eyes were classified as phenotype B and 57 (47%) eyes as phenotype C. Neurodegeneration represented by thinning of the ganglion cell layer and inner plexiform layer was present in both phenotypes and showed significant progression over the two-year period (p<0.001). In phenotype C, significant progression in the two-year period was identified in decreased skeletonized VD (p=0.01), whereas in phenotype B microvascular changes involved preferentially decreases in perfusion density (PD, p=0.012). Phenotype B with changes in VD and PD (flow) and preferential involvement of the deep capillary plexus (p<0.001) is associated with development of center-involved macular edema. DISCUSSION: In the two-year period of follow-up both phenotypes B and C showed progression in retinal neurodegeneration, with changes at the microvascular level characterized by decreases in PD in phenotype B and decreases in VD in phenotype C.

11.
Mol Psychiatry ; 25(8): 1876-1900, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-29950682

RESUMO

Synaptic dysfunction plays a central role in Alzheimer's disease (AD), since it drives the cognitive decline. An association between a polymorphism of the adenosine A2A receptor (A2AR) encoding gene-ADORA2A, and hippocampal volume in AD patients was recently described. In this study, we explore the synaptic function of A2AR in age-related conditions. We report, for the first time, a significant overexpression of A2AR in hippocampal neurons of aged humans, which is aggravated in AD patients. A similar profile of A2AR overexpression in rats was sufficient to drive age-like memory impairments in young animals and to uncover a hippocampal LTD-to-LTP shift. This was accompanied by increased NMDA receptor gating, dependent on mGluR5 and linked to enhanced Ca2+ influx. We confirmed the same plasticity shift in memory-impaired aged rats and APP/PS1 mice modeling AD, which was rescued upon A2AR blockade. This A2AR/mGluR5/NMDAR interaction might prove a suitable alternative for regulating aberrant mGluR5/NMDAR signaling in AD without disrupting their constitutive activity.


Assuntos
Envelhecimento/metabolismo , Depressão Sináptica de Longo Prazo , Neurônios/metabolismo , Receptor A2A de Adenosina/metabolismo , Receptor de Glutamato Metabotrópico 5/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Adenosina/metabolismo , Doença de Alzheimer/metabolismo , Animais , Células Cultivadas , Hipocampo/metabolismo , Humanos , Camundongos , Ratos , Ratos Sprague-Dawley , Memória Espacial
12.
Org Biomol Chem ; 19(9): 1915-1925, 2021 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-33443278

RESUMO

Enzymes are proteins that catalyse chemical reactions and, as such, have been widely used to facilitate a variety of natural and industrial processes, dating back to ancient times. In fact, the global enzymes market is projected to reach $10.5 billion in 2024. The development of computational and DNA editing tools boosted the creation of artificial enzymes (de novo enzymes) - synthetic or organic molecules created to present abiological catalytic functions. These novel catalysts seek to expand the catalytic power offered by nature through new functions and properties. In this manuscript, we discuss the advantages of combining computational design with directed evolution for the development of artificial enzymes and how this strategy allows to fill in the gaps that these methods present individually by providing key insights about the sequence-function relationship. We also review examples, and respective strategies, where this approach has enabled the creation of artificial enzymes with promising catalytic activity. Such key enabling technologies are opening new windows of opportunity in a variety of industries, including pharmaceutical, chemical, biofuels, and food, contributing towards a more sustainable development.


Assuntos
Enzimas/química , Biocatálise , Química Computacional , Reação de Cicloadição , Evolução Molecular Direcionada , Enzimas/genética , Hidrólise , Mutação , Engenharia de Proteínas
13.
Ann Hematol ; 99(5): 937-945, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32166377

RESUMO

Hydroxyurea (HU) is used as a therapy in sickle cell anemia (SCA). Many studies have established that HU improves patient quality of life by reducing symptoms. However, the effect of HU on erythrocytes is not well-described. We evaluated several parameters related to oxidative stress and total lipid content of erythrocytes in patients with SCA. The patient cohort consisted of 7 SCA patients treated with HU, 17 untreated SCA patients, and 15 healthy subjects. Erythrocytes from patients with SCA displayed increased oxidative stress relative to the control group, including higher thiobarbituric acid reactive substances (TBARS), Fe3+ content, and osmotic fragility, and decreased total cholesterol. We observed that treatment of SCA patients with HU increased Fe3+ content and activity of glutathione peroxidase, and decreased glutathione reductase activity, glutathione levels, total cholesterol, and phospholipid content comaperaded to patients untreated with HU. Thus, HU alters biochemical characteristics of erythrocytes; future studies will determine whether they are beneficial or not.


Assuntos
Anemia Falciforme , Eritrócitos Anormais/metabolismo , Hidroxiureia/administração & dosagem , Estresse Oxidativo/efeitos dos fármacos , Adulto , Anemia Falciforme/sangue , Anemia Falciforme/tratamento farmacológico , Colesterol/sangue , Feminino , Humanos , Masculino , Fragilidade Osmótica/efeitos dos fármacos , Fosfolipídeos/sangue , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
14.
BMC Endocr Disord ; 20(1): 21, 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-32028936

RESUMO

BACKGROUND: Adrenal hypoplasia congenita (AHC) is an X-linked disorder that affects the adrenal cortex and hypothalamus-pituitary-gonadal axis (HPG), leading to primary adrenocortical insufficiency (PAI) and hypogonadotropic hypogonadism. AHC is caused by a mutation in the DAX-1 gene (NR0B1). More commonly, this disease is characterized by early-onset PAI, with symptoms in the first months of life. However, a less severe phenotype termed late-onset AHC has been described, as PAI signs and symptoms may begin in adolescence and adulthood. Here we describe a family report of a novel mutation within NR0B1 gene and variable reproductive phenotypes, including spontaneous fertility, in a very late-onset X-linked AHC kindred. CASE PRESENTATION: Three affected maternal male relatives had confirmed PAI diagnosis between 30 y and at late 64 y. The X-linked pattern has made the endocrinology team to AHC suspicion. Regarding the HPG axis, all males presented a distinct degree of testosterone deficiency and fertility phenotypes, varying from a variable degree of hypogonadism, oligoasthenoteratozoospermia to spontaneous fertility. Interestingly, the other five maternal male relatives unexpectedly died during early adulthood, most likely due to undiagnosed PAI/adrenal crisis as the probable cause of their premature deaths. Sequencing analysis of the NR0B1 gene has shown a novel NR0B1 mutation (p.Tyr378Cys) that segregated in three AHC family members. CONCLUSIONS: NR0B1 p.Tyr378Cys segregates in an AHC family with a variable degree of adrenal and gonadal phenotypes, and its hemizygous trait explains the disease in affected family members. We recommend that NR0B1 mutation carriers, even those that are allegedly asymptomatic, be carefully monitored while reinforcing education to prevent PAI and consider early sperm banking when spermatogenesis still viable.


Assuntos
Insuficiência Adrenal/genética , Insuficiência Adrenal/patologia , Receptor Nuclear Órfão DAX-1/genética , Fertilidade , Doenças Genéticas Ligadas ao Cromossomo X/genética , Doenças Genéticas Ligadas ao Cromossomo X/patologia , Reprodução , Adulto , Idade de Início , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Linhagem , Fenótipo , Prognóstico
16.
Acta Oncol ; 54(9): 1423-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26264429

RESUMO

BACKGROUND: Oropharyngeal squamous cell carcinoma (OPSCC) is one of the fastest growing disease sites of head and neck cancers. A recently described radiomic signature, based exclusively on pre-treatment computed tomography (CT) imaging of the primary tumor volume, was found to be prognostic in independent cohorts of lung and head and neck cancer patients treated in the Netherlands. Here, we further validate this signature in a large and independent North American cohort of OPSCC patients, also considering CT artifacts. METHODS: A total of 542 OPSCC patients were included for which we determined the prognostic index (PI) of the radiomic signature. We tested the signature model fit in a Cox regression and assessed model discrimination with Harrell's c-index. Kaplan-Meier survival curves between high and low signature predictions were compared with a log-rank test. Validation was performed in the complete cohort (PMH1) and in the subset of patients without (PMH2) and with (PMH3) visible CT artifacts within the delineated tumor region. RESULTS: We identified 267 (49%) patients without and 275 (51%) with visible CT artifacts. The calibration slope (ß) on the PI in a Cox proportional hazards model was 1.27 (H0: ß = 1, p = 0.152) in the PMH1 (n = 542), 0.855 (H0: ß = 1, p = 0.524) in the PMH2 (n = 267) and 1.99 (H0: ß = 1, p = 0.002) in the PMH3 (n = 275) cohort. Harrell's c-index was 0.628 (p = 2.72e-9), 0.634 (p = 2.7e-6) and 0.647 (p = 5.35e-6) for the PMH1, PMH2 and PMH3 cohort, respectively. Kaplan-Meier survival curves were significantly different (p < 0.05) between high and low radiomic signature model predictions for all cohorts. CONCLUSION: Overall, the signature validated well using all CT images as-is, demonstrating a good model fit and preservation of discrimination. Even though CT artifacts were shown to be of influence, the signature had significant prognostic power regardless if patients with CT artifacts were included.


Assuntos
Carcinoma de Células Escamosas/diagnóstico por imagem , Carcinoma de Células Escamosas/mortalidade , Neoplasias Orofaríngeas/diagnóstico por imagem , Neoplasias Orofaríngeas/mortalidade , Artefatos , Carcinoma de Células Escamosas/terapia , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Neoplasias Orofaríngeas/terapia , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Tomografia Computadorizada Espiral
17.
Acta Oncol ; 54(9): 1289-300, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26395528

RESUMO

BACKGROUND: Trials are vital in informing routine clinical care; however, current designs have major deficiencies. An overview of the various challenges that face modern clinical research and the methods that can be exploited to solve these challenges, in the context of personalised cancer treatment in the 21st century is provided. AIM: The purpose of this manuscript, without intending to be comprehensive, is to spark thought whilst presenting and discussing two important and complementary alternatives to traditional evidence-based medicine, specifically rapid learning health care and cohort multiple randomised controlled trial design. Rapid learning health care is an approach that proposes to extract and apply knowledge from routine clinical care data rather than exclusively depending on clinical trial evidence, (please watch the animation: http://youtu.be/ZDJFOxpwqEA). The cohort multiple randomised controlled trial design is a pragmatic method which has been proposed to help overcome the weaknesses of conventional randomised trials, taking advantage of the standardised follow-up approaches more and more used in routine patient care. This approach is particularly useful when the new intervention is a priori attractive for the patient (i.e. proton therapy, patient decision aids or expensive medications), when the outcomes are easily collected, and when there is no need of a placebo arm. DISCUSSION: Truly personalised cancer treatment is the goal in modern radiotherapy. However, personalised cancer treatment is also an immense challenge. The vast variety of both cancer patients and treatment options makes it extremely difficult to determine which decisions are optimal for the individual patient. Nevertheless, rapid learning health care and cohort multiple randomised controlled trial design are two approaches (among others) that can help meet this challenge.


Assuntos
Medicina Baseada em Evidências/métodos , Neoplasias/radioterapia , Medicina de Precisão/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto , Humanos
18.
BMC Evol Biol ; 14: 116, 2014 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-24891031

RESUMO

BACKGROUND: Why most organisms reproduce via outcrossing rather than selfing is a central question in evolutionary biology. It has long ago been suggested that outcrossing is favoured when it facilitates adaptation to novel environments. We have previously shown that the experimental evolution of increased outcrossing rates in populations of the male-hermaphrodite nematode Caenorhabditis elegans were correlated with the experimental evolution of increased male fitness. However, it is unknown whether outcrossing led to adaptation, and if so, which fitness components can explain the observed increase in outcrossing rates. RESULTS: Using experimental evolution in six populations with initially low standing levels of genetic diversity, we show with head-to-head competition assays that population-wide fitness improved during 100 generations. Since outcrossing rates increased during the same period, this result demonstrates that outcrossing is adaptive. We also show that there was little evolution of hermaphrodite fitness under conditions of selfing or under conditions of outcrossing with unrelated tester males. We nonetheless find a positive genetic correlation between hermaphrodite self-fitness and population-wide fitness, and a negative genetic correlation between hermaphrodite mating success and population-wide fitness. These results suggest that the several hermaphrodite traits measured are fitness components. Tradeoffs expressed in hermaphrodites, particularly noticed between self-fitness and mating success, may in turn explain their lack of change during experimental evolution. CONCLUSIONS: Our findings indicate that outcrossing facilitates adaptation to novel environments. They further indicate that the experimental evolution of increased outcrossing rates depended little on hermaphrodites because of fitness tradeoffs between selfing and outcrossing. Instead, the evolution of increased outcrossing rates appears to have resulted from unhindered selection on males.


Assuntos
Evolução Biológica , Caenorhabditis elegans/fisiologia , Reprodução Assexuada , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Aptidão Genética , Variação Genética , Organismos Hermafroditas/genética , Organismos Hermafroditas/fisiologia , Masculino , Reprodução
19.
BMC Evol Biol ; 14: 117, 2014 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-24891140

RESUMO

BACKGROUND: Classic population genetics theory predicts that mixed reproductive systems, where self reproduction (selfing) and outcrossing co-exist, should not be as common as they are in nature. One means of reconciling theory with observations is to recognize that sexual conflict between males and hermaphrodites and/or constraints in the allocation of resources towards sex functions in hermaphrodites can balance the fitness components of selfing and outcrossing. RESULTS: Using experimental evolution in Caenorhabditis elegans, we test whether the adaptive maintenance of partial selfing is due to sexual conflict and/or to the evolution of sex allocation towards male function in hermaphrodites. For this, we characterized the reproductive schedule and longevity patterns in hermaphrodites under selfing and under outcrossing with naïve males that did not have the opportunity to evolve with them. A shift in reproductive schedule towards earlier reproduction would be indicative of adaptation in our imposed life-cycle, while longevity is expected to evolve as a response to the harm that males impinge on hermaphrodites upon mating. To determine adaptation in the absence of constraints in sex allocation, we also characterized the life history of females that reproduced during experimental evolution through obligate mating with males. As expected with adaptation, we find that after 100 generations of experimental evolution, selfing hermaphrodites and females showed improved reproduction at earlier ages. We did not observe similar reproductive shifts in outcrossed hermaphrodites. We further find increased longevity in outcrossed females after evolution but not in outcrossed hermaphrodites, a result that indicates that sexual conflicts were likely more prevalent under male-female evolution than under male-hermaphrodite evolution. CONCLUSIONS: Taken together, our findings suggest that the adaptive maintenance of partial selfing during C. elegans experimental evolution resulted from the evolution of sex allocation towards male function in hermaphrodites.


Assuntos
Evolução Biológica , Caenorhabditis elegans/fisiologia , Animais , Caenorhabditis elegans/genética , Feminino , Fertilidade , Genética Populacional , Longevidade , Masculino , Dinâmica Populacional , Reprodução
20.
Adv Mater ; 36(10): e2300184, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37102628

RESUMO

Nanozymes represent a class of nanosized materials that exhibit innate catalytic properties similar to biological enzymes. The unique features of these materials have positioned them as promising candidates for applications in clinical sensing devices, specifically those employed at the point-of-care. They notably have found use as a means to amplify signals in nanosensor-based platforms and thereby improve sensor detection limits. Recent developments in the understanding of the fundamental chemistries underpinning these materials have enabled the development of highly effective nanozymes capable of sensing clinically relevant biomarkers at detection limits that compete with "gold-standard" techniques. However, there remain considerable hurdles that need to be overcome before these nanozyme-based sensors can be utilized in a platform ready for clinical use. An overview of the current understandings of nanozymes for disease diagnostics and biosensing applications and the unmet challenges that must be considered prior to their translation in clinical diagnostic tests is provided.


Assuntos
Técnicas Biossensoriais , Nanoestruturas , Catálise , Técnicas Biossensoriais/métodos
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