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1.
Proc Natl Acad Sci U S A ; 119(9)2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35217601

RESUMO

The natural auxin indole-3-acetic acid (IAA) is a key regulator of many aspects of plant growth and development. Synthetic auxin herbicides such as 2,4-D mimic the effects of IAA by inducing strong auxinic-signaling responses in plants. To determine the mechanism of 2,4-D resistance in a Sisymbrium orientale (Indian hedge mustard) weed population, we performed a transcriptome analysis of 2,4-D-resistant (R) and -susceptible (S) genotypes that revealed an in-frame 27-nucleotide deletion removing nine amino acids in the degron tail (DT) of the auxin coreceptor Aux/IAA2 (SoIAA2). The deletion allele cosegregated with 2,4-D resistance in recombinant inbred lines. Further, this deletion was also detected in several 2,4-D-resistant field populations of this species. Arabidopsis transgenic lines expressing the SoIAA2 mutant allele were resistant to 2,4-D and dicamba. The IAA2-DT deletion reduced binding to TIR1 in vitro with both natural and synthetic auxins, causing reduced association and increased dissociation rates. This mechanism of synthetic auxin herbicide resistance assigns an in planta function to the DT region of this Aux/IAA coreceptor for its role in synthetic auxin binding kinetics and reveals a potential biotechnological approach to produce synthetic auxin-resistant crops using gene-editing.


Assuntos
Ácido 2,4-Diclorofenoxiacético , Brassicaceae/genética , Resistência a Herbicidas/genética , Inseticidas , Proteínas de Plantas/genética , Receptores de Superfície Celular/genética , Deleção de Sequência , Brassicaceae/metabolismo , Dicamba , Simulação de Acoplamento Molecular , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Ligação Proteica , Conformação Proteica , RNA de Plantas/genética , Receptores de Superfície Celular/metabolismo , Análise de Sequência de RNA/métodos
2.
J Biol Chem ; 299(11): 105267, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37734554

RESUMO

Herbicides are small molecules that act by inhibiting specific molecular target sites within primary plant metabolic pathways resulting in catastrophic and lethal consequences. The stress induced by herbicides generates reactive oxygen species (ROS), but little is known about the nexus between each herbicide mode of action (MoA) and their respective ability to induce ROS formation. Indeed, some herbicides cause dramatic surges in ROS levels as part of their primary MoA, whereas other herbicides may generate some ROS as a secondary effect of the stress they imposed on plants. In this review, we discuss the types of ROS and their respective reactivity and describe their involvement for each known MoA based on the new Herbicide Resistance Action Committee classification.


Assuntos
Herbicidas , Herbicidas/farmacologia , Herbicidas/metabolismo , Estresse Oxidativo , Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais
3.
Cancer ; 130(19): 3344-3352, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38804723

RESUMO

BACKGROUND: Ponatinib is a third-generation BCR::ABL1 tyrosine kinase inhibitor (TKI) with robust activity in Philadelphia chromosome-positive leukemias. Herein, we report the long-term follow-up of the phase 2 trial of ponatinib in chronic myeloid leukemia in chronic phase. METHODS: Patients received ponatinib 30 to 45 mg/day. The primary end point was the rate of 6-month complete cytogenetic response (CCyR). The study was held in June 2014 because of the risk of cardiovascular toxicity, requiring patients to change TKI. RESULTS: Fifty-one patients were treated with ponatinib (median dose, 45 mg/day). Median age was 48 years (range, 21-75); 30 (59%) had baseline cardiovascular comorbidities. Median treatment duration was 13 months (range, 2-25). Fourteen patients (28%) discontinued ponatinib because of toxicities, 36 (71%) after the Food and Drug Administration warning/study closure, and one for noncompliance. Dasatinib was the most frequently chosen second-line TKI (n = 34; 66%). Among 46 patients evaluable at 6 months, 44 (96%) achieved CCyR, 37 (80%) major molecular response, 28 (61%) MR4, and 21 (46%) MR4.5. The cumulative 6-month rates of CCyR, major molecular response, MR4, and MR4.5 were 96%, 78%, 50%, and 36%, respectively. Durable MR4 ≥24 or ≥60 months was observed in 67% and 51% of patients, respectively. The 24-month event-free survival rate was 97%. After a median follow-up of 128 months, the 10-year overall survival rate was 90%. Eight patients (16%) had serious grade 2 to 3 cardiovascular adverse events, leading to permanent discontinuation in five (10%). CONCLUSION: Ponatinib yielded high cytogenetic and molecular responses in newly diagnosed chronic myeloid leukemia in chronic phase. Its use in the frontline setting is hindered by arterio-/vaso-occlusive and other severe toxicities.


Assuntos
Imidazóis , Leucemia Mielogênica Crônica BCR-ABL Positiva , Inibidores de Proteínas Quinases , Piridazinas , Humanos , Piridazinas/efeitos adversos , Piridazinas/uso terapêutico , Piridazinas/administração & dosagem , Imidazóis/efeitos adversos , Imidazóis/uso terapêutico , Imidazóis/administração & dosagem , Pessoa de Meia-Idade , Adulto , Masculino , Feminino , Idoso , Adulto Jovem , Inibidores de Proteínas Quinases/efeitos adversos , Inibidores de Proteínas Quinases/uso terapêutico , Inibidores de Proteínas Quinases/administração & dosagem , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/mortalidade , Seguimentos , Leucemia Mieloide de Fase Crônica/tratamento farmacológico , Proteínas de Fusão bcr-abl/genética , Proteínas de Fusão bcr-abl/antagonistas & inibidores , Resultado do Tratamento , Dasatinibe/efeitos adversos , Dasatinibe/uso terapêutico , Dasatinibe/administração & dosagem , Antineoplásicos/uso terapêutico , Antineoplásicos/efeitos adversos
4.
Am J Hematol ; 99(6): 1108-1118, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38563187

RESUMO

We investigated using a custom NGS panel of 149 genes the mutational landscape of 64 consecutive adult patients with tyrosine kinase fusion-negative hypereosinophilia (HE)/hypereosinophilic syndrome (HES) harboring features suggestive of myeloid neoplasm. At least one mutation was reported in 50/64 (78%) patients (compared to 8/44 (18%) patients with idiopathic HE/HES/HEUS used as controls; p < .001). Thirty-five patients (54%) had at least one mutation involving the JAK-STAT pathway, including STAT5B (n = 18, among which the hotspot N642H, n = 13), JAK1 (indels in exon 13, n = 5; V658F/L, n = 2), and JAK2 (V617F, n = 6; indels in exon 13, n = 2). Other previously undescribed somatic mutations were also found in JAK2, JAK1, STAT5B, and STAT5A, including three patients who shared the same STAT5A V707fs mutation and features consistent with primary polycythemia. Nearly all JAK-STAT mutations were preceded by (or associated with) myelodysplasia-related gene mutations, especially in RNA-splicing genes or chromatin modifiers. In multivariate analysis, neurologic involvement (hazard ratio [HR] 4.95 [1.87-13.13]; p = .001), anemia (HR 5.50 [2.24-13.49]; p < .001), and the presence of a high-risk mutation (as per the molecular international prognosis scoring system: HR 6.87 [2.39-19.72]; p < .001) were independently associated with impaired overall survival. While corticosteroids were ineffective in all treated JAK-STAT-mutated patients, ruxolitinib showed positive hematological responses including in STAT5A-mutated patients. These findings emphasize the usefulness of NGS for the workup of tyrosine kinase fusion-negative HE/HES patients and support the use of JAK inhibitors in this setting. Updated classifications could consider patients with JAK-STAT mutations and eosinophilia as a new "gene mutated-entity" that could be differentiated from CEL, NOS, and idiopathic HES.


Assuntos
Síndrome Hipereosinofílica , Mutação , Fator de Transcrição STAT5 , Humanos , Síndrome Hipereosinofílica/genética , Síndrome Hipereosinofílica/tratamento farmacológico , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Idoso , Fator de Transcrição STAT5/genética , Janus Quinase 2/genética , Transdução de Sinais , Janus Quinase 1/genética , Idoso de 80 Anos ou mais , Pirimidinas/uso terapêutico , Adulto Jovem
5.
Transfus Apher Sci ; 63(3): 103899, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38402067

RESUMO

BACKGROUND & OBJECTIVES: The primary objective of this observational study was to perform an exhaustive description concerning patients receiving extracorporeal photopheresis (ECP) as second line treatment after steroid resistance for either acute or chronic GVHD following allo-HCT, secondary objectives were to evaluate the efficacy and long-term outcomes. STUDY DESIGN: A total of 106 patients were included, 65 (61%) males and 41 (39%) females with a median age at transplantation of 52 years (range: 20-67). ECP was initiated after transplantation either for acute GVHD [N = 25 (24%), 12 grade III and 13 grade IV] affecting skin alone (N = 5), gut alone (N = 12), gut and liver (N = 8), or chronic GVHD [N = 81 (76%), 15 (14%) limited and 66 (62%) extensive]. RESULTS: Among the 25 patients treated for acute GHVD, 67% were responders and among the 81 patients with chronic GVHD, 78% were responders. Patients with acute GVHD had a median OS of 6 months with a survival probability at 2 years of 35% [95%CI: 14-56]. Patients with chronic GVHD had a median OS of 72 months with a survival probability at 2 years of 68% [95%CI: 56-78]. There was a significant difference in terms of survival for patients responding to ECP compared to non-responders in both acute and chronic GVHD forms. Acute GVHD grade III-IV, negatively impacted on OS (HR=7.77, 95%CI: 1.7-34), p = 0.007 and on disease relapse HR= 5.88, 95%CI: 1.7-20, p = 0.005. CONCLUSION: We demonstrated that ECP is an effective treatment for GVHD in a good proportion of patients with high overall response rate.


Assuntos
Doença Enxerto-Hospedeiro , Neoplasias Hematológicas , Transplante de Células-Tronco Hematopoéticas , Fotoferese , Humanos , Fotoferese/métodos , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Transplante de Células-Tronco Hematopoéticas/métodos , Idoso , Neoplasias Hematológicas/terapia , Doença Crônica , Transplante Homólogo/métodos , Doença Aguda , Adulto Jovem
6.
Br J Haematol ; 201(6): 1116-1124, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37004981

RESUMO

Molecular recurrence (MRec) occurs in about half of all patients with chronic myeloid leukaemia (CML) who discontinue tyrosine kinase inhibitors (TKI) in sustained deep molecular response. A second TKI discontinuation has been attempted in some patients who regain the discontinuation criteria after resuming treatment. Nilotinib treatment affords faster and deeper molecular responses than imatinib as first-line therapy. We prospectively evaluated the efficacy and safety of nilotinib (300 mg twice daily) in chronic-phase CML patients who experienced MRec, after imatinib discontinuation and analysed the probability of TFR after a new attempt in patients treated for 2 years with sustained MR4.5 for at least 1 year. A total of 31 patients were included in the study between 2013 and 2018. Seven (23%) patients experienced serious adverse events after a median of 2 months of nilotinib treatment leading to discontinuation of treatment. One patient was excluded from the study for convenience. Among the 23 patients treated for 2 years with nilotinib, 22 maintained their molecular response for at least 1 year (median: 22 months) and stopped nilotinib. The TFR rates at 24 and 48 months after nilotinib discontinuation were 59.1% (95% confidence interval [CI]: 41.7%-83.7%) and 42.1% (95% CI: 25%-71%) respectively (NCT #01774630).


Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva , Inibidores de Proteínas Quinases , Humanos , Mesilato de Imatinib/efeitos adversos , Inibidores de Proteínas Quinases/efeitos adversos , Pirimidinas/efeitos adversos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Resultado do Tratamento
7.
Br J Haematol ; 200(2): 175-186, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36214090

RESUMO

Superior rates of deep molecular response (DMR) have been reported with the combination of tyrosine kinase inhibitors and pegylated-interferon-alpha (Peg-IFN) in patients with newly diagnosed chronic phase-chronic myeloid leukaemia (CP-CML). In this setting, this study investigated the efficacy and safety of dasatinib combined to Peg-IFN-α2b (Dasa-PegIFN, NCT01872442). A total of 79 patients (age ≤65 years) started dasatinib; 61 were eligible for Peg-IFNα-2b add-on therapy at month 3 for a maximum 21-months duration. Dasatinib was continued thereafter. The primary endpoint was the cumulative rate of molecular response 4.5 log (MR4.5 ) by 12 months. The results are reported for the 5-year duration of the study. Grade 3 neutropenia was frequent with the combination but did not induce severe infection (one of grade 3). Other adverse events were generally low grade (4% of grade 3-4) and expected. Seventy-nine per cent and 61% of patients continued the Peg-IFN until months 12 and 24, respectively. Overall, at these time points, MR4.5 rates were 25% and 38%, respectively. Thereafter, 32% and 46% of patients achieved a sustained (≥2 years) MR4.5 or MR4 , respectively. This work established the feasibility and high rates of achievement of early and sustained DMR (a prerequisite for treatment-free-remission) with dasatinib and Peg-IFNα-2b combination as initial therapy.


Assuntos
Interferon-alfa , Leucemia Mieloide de Fase Crônica , Humanos , Idoso , Dasatinibe/efeitos adversos , Interferon-alfa/efeitos adversos , Leucemia Mieloide de Fase Crônica/tratamento farmacológico , Polietilenoglicóis/efeitos adversos , Resultado do Tratamento
8.
Am J Hematol ; 98(11): 1762-1771, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37647134

RESUMO

Disease progression to accelerated/blast phase (AP/BP) in patients with chronic phase chronic myeloid leukemia (CP-CML) after treatment discontinuation (TD) has never been systematically reported in clinical trials. However, recent reports of several such cases has raised concern. To estimate the risk of AP/BP among TD-eligible patients, we conducted TFR-PRO, a cohort retro-prospective study: 870 CP-CML patients eligible for TD formed a discontinuation cohort (505 patients) and a reference one (365 patients). The primary objective was the time adjusted rate (TAR) of progression in relation to TD. Secondary endpoints included the TAR of molecular relapse, that is, loss of major molecular response (MMR). With a median follow up of 5.5 years and 5188.2 person-years available, no events occurred in the TD cohort. One event of progression was registered 55 months after the end of TD, when the patient was contributing to the reference cohort. The TAR of progression was 0.019/100 person-years (95% CI [0.003-0.138]) in the overall group; 0.0 (95% CI [0-0.163]) in the discontinuation cohort; and 0.030 (95% CI [0.004-0.215]) in the reference cohort. These differences are not statistically significant. Molecular relapses occurred in 172/505 (34.1%) patients after TD, and in 64/365 (17.5%) patients in the reference cohort, p < .0001. Similar rates were observed in TD patients in first, second or third line of treatment. CML progression in patients eligible for TD is rare and not related to TD. Fears about the risk of disease progression among patients attempting TD should be dissipated.

9.
Clin Gerontol ; 46(3): 433-445, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36255289

RESUMO

OBJECTIVES: Gender has been identified as an important social determinant for health. This study investigates gender-specific characteristics for alcohol use (AU) among community-dwelling older adults. METHODS: This is a retrospective cross-sectional study in 1,406 community-dwelling older adults. We used standardized questionnaires to collect self-reported data on alcohol use behavior, mental health, drinking motives and resilience by using, respectively, the Alcohol Use Identification Test (AUDIT), the Brief Symptom Inventory (BSI), the Drinking Motives Questionnaire (DMQ), and the Connor-Davidson Resilience Scale (CD-RISC). Multiple linear regression was used to identify the joint contribution of those factors on AU. Hierarchical regression was used to investigate the influence of the interaction between gender and those factors on AU. RESULTS: Linear regression analyses showed different associations with AU in men and women. Hierarchical regression analyses showed that gender presented a two-way interaction effect with enhancement and anxiety variables related to AU. CONCLUSIONS: Different characteristics were found as predictors for AU among older men and women. CLINICAL IMPLICATIONS: Clinicians and health-care providers should be aware of these differences in order to provide tailored screening and intervention programs to reduce AU in older adults.


Assuntos
Consumo de Bebidas Alcoólicas , Vida Independente , Masculino , Humanos , Feminino , Idoso , Consumo de Bebidas Alcoólicas/epidemiologia , Consumo de Bebidas Alcoólicas/psicologia , Bélgica/epidemiologia , Estudos Transversais , Estudos Retrospectivos
10.
Haematologica ; 107(12): 2859-2869, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-35615931

RESUMO

Discontinuation of tyrosine kinase inhibitors in chronic phase chronic myeloid leukemia is feasible in clinical practice based on recently published international recommendations. Nevertheless, factors predictive of molecular recurrence have not been fully elucidated and long-term follow-up of patients enrolled in clinical studies are required in order to update knowledge on discontinuation attempts particularly in terms of the safety and durability of treatment-free remission (TFR). In the current study, we updated results from the STIM2 study in the light of the consensual criterion of molecular recurrence reported in different international recommendations. Among the 199 patients included in the perprotocol study, 108 patients lost a major molecular response. With a median follow-up of 40.8 months (5.5-111 months), the probability of treatment-free remission was 43.4% [36.3-50.4] at 5 years, 40.9% [32.8-47.3] at 7 years and 34.5% [25.6- 43.3] at 9 years. Molecular recurrence occurred between 0 to 6 months, 6 to 24 months and after 24 months in 75 patients (69%), 15 patients (14%) and 18 patients (17%), respectively. Notably, the kinetics of molecular recurrence differed significantly between these three subgroups with a median time from loss of MR4 (BCR::ABL1 IS≤0.01%) to loss of major molecular response of 1, 7 and 22 months, respectively. Predictive factors of molecular recurrence differed according to the time of occurrence of the molecular recurrence. Durations of imatinib treatment and deep molecular response as well as BCR::ABL1/ABL1 levels at cessation of tyrosine kinase inhibitor treatment, as quantified by reverse transcriptase droplet digital polymerase chain reaction, are involved in molecular recurrence occurring up to 24 months but not beyond. (ClinicalTrial. gov Identifier NCT#0134373).


Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva , Leucemia Mieloide de Fase Crônica , Humanos , Proteínas de Fusão bcr-abl/genética , Mesilato de Imatinib/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mieloide de Fase Crônica/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Indução de Remissão , Molécula 2 de Interação Estromal , Resultado do Tratamento
11.
Am J Hematol ; 97(11): 1419-1426, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36054756

RESUMO

Ponatinib, the only third-generation pan-BCR::ABL1 inhibitor with activity against all known BCR::ABL1 mutations including T315I, has demonstrated deep and durable responses in patients with chronic-phase chronic myeloid leukemia (CP-CML) resistant to prior second-generation (2G) TKI treatment. We present efficacy and safety outcomes from the Ponatinib Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) and CML Evaluation (PACE) and Optimizing Ponatinib Treatment in CP-CML (OPTIC) trials for this patient population. PACE (NCT01207440) evaluated ponatinib 45 mg/day in CML patients with resistance to prior TKI or T315I. In OPTIC (NCT02467270), patients with CP-CML and resistance to ≥2 prior TKIs or T315I receiving 45 or 30 mg/day reduced their doses to 15 mg/day upon achieving ≤1% BCR::ABL1IS or received 15 mg/day continuously. Efficacy and safety outcomes from patients with CP-CML treated with ≥1 2G TKI (PACE, n = 257) and OPTIC (n = 93), 45-mg starting dose cohort, were analyzed for BCR::ABL1IS response rates, overall survival (OS), progression-free survival (PFS), and safety. By 24 months, the percentages of patients with ≤1% BCR::ABL1IS response, PFS, and OS were 46%, 68%, and 85%, respectively, in PACE and 57%, 80%, and 91%, respectively, in OPTIC. Serious treatment-emergent adverse events and serious treatment-emergent arterial occlusive event rates were 63% and 18% in PACE and 34% and 4% in OPTIC. Ponatinib shows high response rates and robust survival outcomes in patients whose disease failed prior to 2G TKIs, including patients with T315I mutation. The response-based dosing in OPTIC led to improved safety and similar efficacy outcomes compared with PACE.


Assuntos
Imidazóis , Leucemia Mielogênica Crônica BCR-ABL Positiva , Leucemia Mieloide de Fase Crônica , Piridazinas , Ensaios Clínicos como Assunto , Resistencia a Medicamentos Antineoplásicos/genética , Proteínas de Fusão bcr-abl/genética , Humanos , Imidazóis/efeitos adversos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mieloide de Fase Crônica/tratamento farmacológico , Leucemia Mieloide de Fase Crônica/genética , Inibidores de Proteínas Quinases/efeitos adversos , Piridazinas/efeitos adversos
12.
Aging Ment Health ; 26(1): 56-64, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-33445980

RESUMO

INTRODUCTION: We examined the psychometric properties of the CD-RISC, including factor structure. Secondly, we examined if resilience factors moderate the association between negative affect and hazardous alcohol use. METHOD: The sample population consisted of 1,368 community-dwelling older adults. We used standardized questionnaires to collect self-reported data on alcohol use behaviour, depression and anxiety and resilience by using respectively the Alcohol Use Identification Test (AUDIT), the Brief Symptom Inventory (BSI) and the Connor-Davidson Resilience Scale (CD-RISC). RESULTS: Of the total sample (N 1.368), 80.1% reported using alcohol. The total sample and the drinking sample reported, respectively, a mean of 65.75 (SD 15.40) and 65.79 (SD 15.90) on the CD-RISC. Concerning the CD-RISC, exploratory factor analysis presents four factors of which three with a good reliability. Moderation analyses reflects that older adults with higher levels of resilient characteristics didn't report an association between negative affect and hazardous drinking. Alternatively, low resilient older adults did report an positive and significant association between negative affect and hazardous drinking. CONCLUSION: The CD-RISC appeared to be a reliable instrument, containing three factors. In our sample, high resilience moderated the association between negative affect and hazardous drinking and may serve as a buffer against hazardous drinking.


Assuntos
Vida Independente , Resiliência Psicológica , Idoso , Ansiedade/epidemiologia , Depressão/epidemiologia , Humanos , Psicometria , Reprodutibilidade dos Testes , Inquéritos e Questionários
13.
J Biol Chem ; 295(30): 10307-10330, 2020 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-32430396

RESUMO

The widely successful use of synthetic herbicides over the past 70 years has imposed strong and widespread selection pressure, leading to the evolution of herbicide resistance in hundreds of weed species. Both target-site resistance (TSR) and nontarget-site resistance (NTSR) mechanisms have evolved to most herbicide classes. TSR often involves mutations in genes encoding the protein targets of herbicides, affecting the binding of the herbicide either at or near catalytic domains or in regions affecting access to them. Most of these mutations are nonsynonymous SNPs, but polymorphisms in more than one codon or entire codon deletions have also evolved. Some herbicides bind multiple proteins, making the evolution of TSR mechanisms more difficult. Increased amounts of protein target, by increased gene expression or by gene duplication, are an important, albeit less common, TSR mechanism. NTSR mechanisms include reduced absorption or translocation and increased sequestration or metabolic degradation. The mechanisms that can contribute to NTSR are complex and often involve genes that are members of large gene families. For example, enzymes involved in herbicide metabolism-based resistances include cytochromes P450, GSH S-transferases, glucosyl and other transferases, aryl acylamidase, and others. Both TSR and NTSR mechanisms can combine at the individual level to produce higher resistance levels. The vast array of herbicide-resistance mechanisms for generalist (NTSR) and specialist (TSR and some NTSR) adaptations that have evolved over a few decades illustrate the evolutionary resilience of weed populations to extreme selection pressures. These evolutionary processes drive herbicide and herbicide-resistant crop development and resistance management strategies.


Assuntos
Sistema Enzimático do Citocromo P-450/biossíntese , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Resistência a Herbicidas/fisiologia , Herbicidas/farmacologia , Proteínas de Plantas/biossíntese , Plantas/enzimologia , Aclimatação , Herbicidas/metabolismo
14.
Br J Haematol ; 194(2): 393-402, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34195988

RESUMO

Dasatinib is a second-generation BCR-ABL1 tyrosine kinase inhibitor approved for patients with chronic myeloid leukaemia (CML). Dasatinib 100 mg per day is associated with an increased risk of pleural effusion (PlEff). We randomly evaluated whether therapeutic drug monitoring (TDM) may reduce dasatinib-associated significant adverse events (AEs) by 12 months (primary endpoint). Eligible patients started dasatinib at 100 mg per day followed by dasatinib (C)min assessment. Patients considered overdosed [(C)min ≥ 3 nmol/l) were randomised between a dose-reduction strategy (TDM arm) and standard of care (control arm). Out of 287 evaluable patients, 80 patients were randomised. The primary endpoint was not met due to early haematological AEs occurring before effective dose reduction. However, a major reduction in the cumulative incidence of PlEff was observed in the TDM arm compared to the control arm (4% vs. 15%; 11% vs. 35% and 12% vs. 39% at one, two and three years, respectively (P = 0·0094)). Molecular responses were superimposable in all arms. Dasatinib TDM during treatment initiation was feasible and resulted in a significant reduction of the incidence of PlEff in the long run, without impairing molecular responses. (NCT01916785; https://clinicaltrials.gov).


Assuntos
Antineoplásicos/uso terapêutico , Dasatinibe/uso terapêutico , Monitoramento de Medicamentos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Derrame Pleural/induzido quimicamente , Inibidores de Proteínas Quinases/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Dasatinibe/administração & dosagem , Dasatinibe/efeitos adversos , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Derrame Pleural/prevenção & controle , Estudos Prospectivos , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/efeitos adversos , Resultado do Tratamento , Adulto Jovem
15.
Photosynth Res ; 144(3): 361-372, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32372199

RESUMO

Glufosinate targets glutamine synthetase (GS), but its fast herbicidal action is triggered by reactive oxygen species (ROS). The relationship between GS inhibition and ROS accumulation was investigated in Amaranthus palmeri. Glufosinate's fast action is light-dependent with no visual symptoms or ROS formation in the dark. Inhibition of GS leads to accumulation of ammonia and metabolites of the photorespiration pathway, such as glycolate and glyoxylate, as well as depletion of other intermediates such as glycine, serine, hydroxypyruvate, and glycerate. Exogenous supply of glycolate to glufosinate-treated plants enhanced herbicidal activity and dramatically increased hydrogen peroxide accumulation (possibly from peroxisomal glycolate oxidase activity). Glufosinate affected the balance between ROS generation and scavenging. The activity of superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase increased after glufosinate treatment in an attempt to quench the nascent ROS burst. Low doses of atrazine and dinoseb were used to investigate the sources of ROS by manipulating photosynthetic electron transport and oxygen (O2) evolution. ROS formation depended on electron flow and O2 evolution in photosystem II (PSII). Inhibition of GS disrupted photorespiration, carbon assimilation, and linear electron flow in the light reactions. Consequently, the antioxidant machinery and the water-water cycle are overwhelmed in the presence of light and glufosinate. The O2 generated by the splitting of water in PSII becomes the acceptor of electrons, generating ROS. The cascade of events leads to lipid peroxidation and forms the basis for the fast action of glufosinate.


Assuntos
Aminobutiratos/farmacologia , Transporte de Elétrons , Glicolatos/farmacologia , Herbicidas/farmacologia , Fotossíntese/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Antioxidantes/metabolismo , Ascorbato Peroxidases/metabolismo , Catalase/metabolismo , Glutamato-Amônia Ligase/metabolismo , Glicina/metabolismo , Oxigênio/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Proteínas de Plantas/metabolismo , Superóxido Dismutase/metabolismo
16.
Blood ; 132(4): 393-404, 2018 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-29567798

RESUMO

Ponatinib has potent activity against native and mutant BCR-ABL1, including BCR-ABL1T315I The pivotal phase 2 Ponatinib Ph+ ALL and CML Evaluation (PACE) trial evaluated efficacy and safety of ponatinib at a starting dose of 45 mg once daily in 449 patients with chronic myeloid leukemia (CML) or Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL) resistant/intolerant to dasatinib or nilotinib, or with BCR-ABL1T315I This analysis focuses on chronic-phase CML (CP-CML) patients (n = 270) with 56.8-month median follow-up. Among 267 evaluable patients, 60%, 40%, and 24% achieved major cytogenetic response (MCyR), major molecular response (MMR), and 4.5-log molecular response, respectively. The probability of maintaining MCyR for 5 years was 82% among responders. Dose reductions were implemented in October 2013 to decrease the risk of arterial occlusive events (AOEs); ≥90% of CP-CML patients who had achieved MCyR or MMR maintained response 40 months after elective dose reductions. Estimated 5-year overall survival was 73%. In CP-CML patients, the most common treatment-emergent adverse events were rash (47%), abdominal pain (46%), thrombocytopenia (46%), headache (43%), dry skin (42%), and constipation (41%). The cumulative incidence of AOEs in CP-CML patients increased over time to 31%, while the exposure-adjusted incidence of new AOEs (15.8 and 4.9 per 100 patient-years in years 1 and 5, respectively) did not increase over time. These final PACE results demonstrate ponatinib provides durable and clinically meaningful responses, irrespective of dose reductions, in this population of heavily pretreated CP-CML patients. This trial was registered at www.clinicaltrials.gov as #NCT01207440.


Assuntos
Antineoplásicos/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Imidazóis/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Cromossomo Filadélfia , Piridazinas/uso terapêutico , Terapia de Salvação , Adulto , Idoso , Idoso de 80 Anos ou mais , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Seguimentos , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Segurança , Taxa de Sobrevida , Fatores de Tempo , Adulto Jovem
17.
Am J Hematol ; 95(11): 1314-1323, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32720700

RESUMO

FIP1L1-PDGFRA-positive myeloid neoplasm with eosinophilia (F/P+ MN-eo) is a rare disease: robust epidemiological data are lacking and reported issues are scarce, of low sample-size and limited follow-up. Imatinib mesylate (IM) is highly efficient but no predictive factor of relapse after discontinuation has yet been identified. One hundred and fifty-one patients with F/P+ MN-eo (143 males; mean age at diagnosis 49 years; mean annual incidence: 0.18 case per million population) were included in this retrospective nationwide study involving all French laboratories who perform the search of F/P fusion gene (study period: 2003-2019). The main organs involved included the spleen (44%), skin (32%), lungs (30%), heart (19%) and central nervous system (9%). Serum vitamin B12 and tryptase levels were elevated in 74/79 (94%) and 45/57 (79%) patients, respectively, and none of the 31 patients initially treated with corticosteroids achieved complete hematologic remission. All 148 (98%) IM-treated patients achieved complete hematologic and molecular (when tested, n = 84) responses. Forty-six patients eventually discontinued IM, among whom 20 (57%) relapsed. In multivariate analysis, time to IM initiation (continuous HR: 1,01 [0.99-1,03]; P = .05) and duration of IM treatment (continuous HR: 0,97 [0,95-0,99]; P = .004) were independent factors of relapse after discontinuation of IM. After a mean follow-up of 80 (56) months, the 1, 5- and 10-year overall survival rates in IM-treated patients were 99%, 95% and 84% respectively. In F/P+ MN-eo, prompt initiation of IM and longer treatment durations may prevent relapses after discontinuation of IM.


Assuntos
Corticosteroides/administração & dosagem , Eosinofilia , Neoplasias Hematológicas , Transtornos Mieloproliferativos , Proteínas de Fusão Oncogênica , Receptor alfa de Fator de Crescimento Derivado de Plaquetas , Fatores de Poliadenilação e Clivagem de mRNA , Adulto , Intervalo Livre de Doença , Eosinofilia/sangue , Eosinofilia/tratamento farmacológico , Eosinofilia/genética , Eosinofilia/mortalidade , Feminino , França/epidemiologia , Neoplasias Hematológicas/sangue , Neoplasias Hematológicas/tratamento farmacológico , Neoplasias Hematológicas/genética , Neoplasias Hematológicas/mortalidade , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Transtornos Mieloproliferativos/sangue , Transtornos Mieloproliferativos/tratamento farmacológico , Transtornos Mieloproliferativos/genética , Transtornos Mieloproliferativos/mortalidade , Proteínas de Fusão Oncogênica/sangue , Proteínas de Fusão Oncogênica/genética , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/sangue , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Estudos Retrospectivos , Taxa de Sobrevida , Triptases/sangue , Vitamina B 12/sangue , Fatores de Poliadenilação e Clivagem de mRNA/sangue , Fatores de Poliadenilação e Clivagem de mRNA/genética
18.
J Nat Prod ; 83(4): 843-851, 2020 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-32091209

RESUMO

The culture broth of Burkholderia rinojensis strain A396 is herbicidal to a number of weed species with greater observed efficacy against broadleaf than grass weeds. A portion of this activity is attributed to romidepsin, a 16-membered cyclic depsipeptide bridged by a 15-membered macrocyclic disulfide. Romidepsin, which is present in small amounts in the broth (18 to 25 µg mL-1), was isolated and purified using standard chromatographic techniques. It was established that romidepsin is a natural proherbicide that targets the activity of plant histone deacetylases (HDAC). Assays to measure plant HDAC activity were optimized by testing a number of HDAC substrates. The activity of romidepsin was greater when its macrocyclic-forming disulfide bridge was reduced to liberate a highly reactive free butenyl thiol side chain. Reduction was achieved using 200 mM tris(2-carboxyethyl)phosphine hydrochloride. A similar bioactivation of the proherbicide via reduction of the disulfide bridge of romidepsin was observed in plant-cell-free extracts. Molecular dynamic simulation of the binding of romidepsin to Arabidopsis thaliana HDAC19 indicated the reduced form of the compound could reach deep inside the catalytic domain and interact with an associated zinc atom required for enzyme activity.


Assuntos
Agentes de Controle Biológico/química , Agentes de Controle Biológico/farmacologia , Burkholderia/química , Depsipeptídeos/química , Depsipeptídeos/farmacologia , Herbicidas/química , Herbicidas/farmacologia , Arabidopsis , Cromatografia Líquida de Alta Pressão , Cucumis sativus/química , Meios de Cultura/química , Dissulfetos , Inibidores de Histona Desacetilases/farmacologia , Simulação de Dinâmica Molecular , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Especificidade por Substrato
19.
Clin J Sport Med ; 30(1): e8-e10, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-30383546

RESUMO

For high-level athletes, most experts consider that 1-level arthrodesis in cervical spine surgery does not prevent return to play. Nevertheless, return remains controversial in cases of 2-level fusions. We report the case of a 27-year-old professional rugby player. He had had a double cervical fusion C5C6 and C6C7 for cervical hernia and was allowed to continue rugby activities afterward. Four years after this surgery, his neck was forced in hyperflexion during a match and complete tetraplegia occurred. A computed tomography scan showed a C3C4 unilateral facet dislocation. The patient was rapidly operated on. At follow-up, 2 years after the accident, the patient remained tetraplegic with no neurologic improvement. If no definitive conclusion can be established on this first observation, many precautions must be taken before a return-to-play decision, especially in contact sports.


Assuntos
Artrodese/métodos , Vértebras Cervicais/lesões , Vértebras Cervicais/cirurgia , Futebol Americano/lesões , Deslocamento do Disco Intervertebral/cirurgia , Complicações Pós-Operatórias , Quadriplegia/etiologia , Adulto , Humanos , Luxações Articulares/etiologia , Masculino , Volta ao Esporte , Traumatismos da Medula Espinal/etiologia
20.
Pestic Biochem Physiol ; 164: 1-6, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32284114

RESUMO

Sourgrass (Digitaria insularis) is one of the most problematic weeds in South America because glyphosate resistance is widespread across most crop production regions. Acetyl coenzyme A carboxylase (ACCase)-inhibiting herbicides have been intensively used to manage D. insularis, which substantially increased selection pressure for this class of herbicides. We confirmed resistance to ACCase herbicides in a D. insularis population from Brazil and characterized its molecular basis. Resistant plants showed high level of resistance to haloxyfop (resistance factor, RF = 613-fold), low level of resistance to pinoxaden (RF = 3.6-fold), and no resistance to clethodim. A target-site mutation, Trp2027Cys, was found in the ACCase sequence from resistant plants. A protein homology model shows that the Trp2027Cys mutation is near the herbicide-binding pocket formed between two ACCase chains, and is predicted to obstruct the access of aryloxyphenoxypropionates (FOP) herbicides to the binding site. A qPCR-based single nucleotide polymorphism genotyping method was validated to discriminate susceptible (wild-type Trp2027) and resistant (mutant Cys2027) alleles. All resistant plants were homozygous for the mutation and the assay could be used for early detection of resistance in D. insularis field samples with suspected resistance to ACCase inhibitors.


Assuntos
Digitaria , Herbicidas , Acetil-CoA Carboxilase , Brasil , Resistência a Herbicidas , Mutação , Poaceae
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