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1.
bioRxiv ; 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-39005268

RESUMO

Pancreatic ductal adenocarcinoma-(PDAC) needs innovative approaches due to its 12% 5-year survival despite current therapies. We show marked sensitivity of pancreatic cancer cells to the combination of a novel eIF4A inhibitor, des-methyl pateamine A (DMPatA), and a histone deacetylase inhibitor, romidepsin, inducing epigenetic reprogramming as an innovative therapeutic strategy. Exploring the mechanistic activity of this combination showed that with a short duration of romidepsin at low doses, robust acetylation persisted up to 48h with the combination, while histone acetylation rapidly faded with monotherapy. This represents an unexpected mechanism of action against PDAC cells that triggers transcriptional overload, metabolic stress, and augmented DNA damage. Structurally different class I HDAC inhibitors exhibit the same hyperacetylation patterns when co-administered with DMPatA, suggesting a class effect. We show efficacy of this combination regimen against tumor growth in a MIA PaCa-2 xenograft model of PDAC with persistent hyperacetylation confirmed in tumor samples. STATEMENT OF SIGNIFICANCE: Pancreatic ductal adenocarcinoma, a significant clinical challenge, could benefit from the latent potential of epigenetic therapies like HDAC inhibitors-(HDIs), typically limited to hematological malignancies. Our study shows that a synergistic low dose combination of HDIs with an eIF4A-inhibitor in pancreatic cancer models results in marked pre-clinical efficacy, offering a promising new treatment strategy.

2.
Macromolecules ; 56(19): 7879-7888, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37841533

RESUMO

Melt memory effects in polymer crystallization have attracted much attention in the past few years. Although progress has been made in understanding how the chemical structure of polymers can affect melt memory, there are still some knowledge gaps. In this work, we study how incorporating a second comonomer unit that is partially included in the crystalline unit cell affects the melt memory effect of the major component in a random isodimorphic copolymer for the first time. This second comonomer unit depresses the melting temperature of the homopolymer, reduces the crystallinity, and distorts the crystalline unit cell. However, its effect on the stability of self-nuclei and the production of melt memory has not been studied so far. To this aim, we have selected poly[(butylene succinate)-ran-(ε-caprolactone)] random copolyesters PBS-ran-PCL that are isodimorphic, i.e., they exhibit a pseudoeutectic point. This point separates the formation of BS-rich crystals from CL-rich crystals as a function of composition. The results reveal that the melt memory effect of these isodimorphic copolymers is strongly reduced with the incorporation of even very small amounts of comonomer unit (i.e., 1 molar %). This indicates that the incorporation of a second comonomer unit in the polymer chain disrupts the intermolecular interactions present between the chain segments in the crystal lattice of the major component and reduces the capacity of the material to produce self-nuclei. This reduction is more drastic for copolymers in which the second comonomer unit is mostly rejected from the crystalline phase. Contrary to olefin-based copolymers, for copolyesters, the second comonomer unit eases the process to reach an isotropic melt state upon melting. This work reveals the impact of introducing comonomer units on the melt memory effect in isodimorphic random copolyesters.

3.
Cancers (Basel) ; 15(20)2023 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-37894327

RESUMO

BACKGROUND: Over the last few decades of treatment, the outcomes for at least some subsets of neuroendocrine neoplasms (NENs) have improved. However, the identification of new vulnerabilities for this heterogeneous group of cancers remains a priority. METHODS: Using two libraries of compounds selected for potential repurposing, we identified the inhibitors of nicotinamide phosphoribosyltransferase (NAMPT) and histone deacetylases (HDAC) as the agents with the highest activity. We validated the hits in an expanded set of neuroendocrine cell lines and examined the mechanisms of action. RESULTS: In Kelly, NH-6, and NCI-H82, which are two neuroblastoma and one small cell lung cancer cell lines, respectively, metabolic studies suggested that cell death following NAMPT inhibition is the result of a reduction in basal oxidative phosphorylation and energy production. NAMPT is the rate-limiting enzyme in the production of NAD+, and in the three cell lines, NAMPT inhibition led to a marked reduction in the ATP and NAD+ levels and the catalytic activity of the citric acid cycle. Moreover, comparative analysis of the mRNA expression in drug-sensitive and -insensitive cell lines found less dependency of the latter on oxidative phosphorylation for their energy requirement. Further, the analysis of HDAC and NAMPT inhibitors administered in combination found marked activity using low sub-lethal concentrations of both agents, suggesting a synergistic effect. CONCLUSION: These data suggest NAMPT inhibitors alone or in combination with HDAC inhibitors could be particularly effective in the treatment of neuroendocrine neoplasms.

4.
Cancers (Basel) ; 14(11)2022 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-35681624

RESUMO

BACKGROUND: The mechanism of action of romidepsin and other histone deacetylase inhibitors is still not fully explained. Our goal was to gain a mechanistic understanding of the RAS-linked phenotype associated with romidepsin sensitivity. METHODS: The NCI60 dataset was screened for molecular clues to romidepsin sensitivity. Histone acetylation, DNA damage, ROS production, metabolic state (real-time measurement and metabolomics), and gene expression alterations (transcriptomics) were determined in KRAS-WT versus KRAS-mutant cell groups. The search for biomarkers in response to HDACi was implemented by supervised machine learning analysis on a 608-cell transcriptomic dataset and validated in a clinical dataset. RESULTS: Romidepsin treatment induced depletion in acetyl-CoA in all tested cell lines, which led to oxidative stress, metabolic stress, and increased death-particularly in KRAS-mutant cell lines. Romidepsin-induced stresses and death were rescued by acetyl-CoA replenishment. Two acetyl-CoA gene expression signatures associated with HDACi sensitivity were derived from machine learning analysis in the CCLE (Cancer Cell Line Encyclopedia) cell panel. Signatures were then validated in the training cohort for seven HDACi, and in an independent 13-patient cohort treated with belinostat. CONCLUSIONS: Our study reveals the importance of acetyl-CoA metabolism in HDAC sensitivity, and it highlights acetyl-CoA generation pathways as potential targets to combine with HDACi.

5.
Int J Biol Macromol ; 214: 128-139, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35700846

RESUMO

This work presents, for the first time, a detailed report on how the nucleation and crystallization of polylactide (PLLA) are affected by biobased aliphatic polyesters plasticizers. Three biobased polyesters were synthesized via solvent-free two-stage melt polycondensation of adipic acid (AdA) with three different biobased aliphatic diols and used as plasticizers for poly (L-lactic acid) (PLLA). The molecular structure of the synthesized polyesters was proved using 1H NMR, 13C NMR and Fourier transform infrared (FTIR) spectroscopy. PLLA/AdA-based blends containing 10 wt% of the polyester plasticizers were studied by tensile tests, dynamic mechanical analysis (DMA), wide-angle x-ray scattering (WAXS), differential scanning calorimetry (DSC) and polarized light optical microscopy (PLOM). Adding the plasticizers to PLLA decreased Tg by up to 11 °C and significantly increased the elongation at break by about 8 times compared with neat PLLA. The addition of 10 wt% of any AdA-based plasticizer to PLLA increases the nucleation rate from the glassy state by around 50-110 % depending on the plasticizer. The overall crystallization rate from the glassy state was 2-3 times faster for the plasticized PLLAs than neat PLLA. These results are a consequence of the lower energy barrier for both nucleation and growth processes. The incorporation of AdA-based linear polyesters had an incremental impact on the crystal growth rate (or secondary nucleation) of PLLA spherulites from the melt and glassy states. In conclusion, the AdA-based aliphatic polyesters allowed to enhance PLLA crystallization rates and showed interesting potential for the formulation of fully biobased PLLA blends.


Assuntos
Plastificantes , Poliésteres , Varredura Diferencial de Calorimetria , Cristalização , Poliésteres/química
6.
Polymers (Basel) ; 14(3)2022 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-35160612

RESUMO

The sole effect of the microstructure of biodegradable isodimorphic poly(butylene succinate)-ran-poly(ε-caprolactone) random copolyesters on their rheological properties is investigated. To avoid the effect of molecular weight and temperature, two rheological procedures are considered: the activation energy of flow, Ea, and the phase angle versus complex modulus plots. An unexpected variation of both parameters with copolyester composition is observed, with respective maximum and minimum values for the 50/50 composition. This might be due to the peculiar chain configurations of the copolymers that vary as a function of comonomer distribution within the chains. The same chain configuration variations are responsible for the isodimorphic character of the copolymers in the crystalline state. Tack tests, performed to study the viability of the copolyesters as environmentally friendly hot melt adhesives (HMA), reveal a correlation with rheological results. Tackiness parameters, particularly the energy of adhesion obtained from stress-strain curves during debonding experiments, are enhanced as melt elasticity increases. Based on the carried-out analysis, the link microstructure-rheology-tackiness is established, allowing selecting the best performing HMA sample considering the polymer chemistry of the system.

7.
Heliyon ; 7(10): e08232, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34934828

RESUMO

Frontier market banks fill key funding gaps in the markets they serve, resulting in increased evaluation (a positive) and earnings management (EM) (a negative). Examination of a large sample of banks in 22 frontier market countries from 2001 to 2018 reveals a downward trend in efficiency, indicating that loan quality issues persist despite increasing economic growth in the respective countries. Using stochastic frontier analysis to quantify efficiency and random effects and truncated regression to investigate the EM-efficiency relation, this study demonstrates that efficiency is negatively associated with EM. Furthermore, there was no clear relationship between bank size and efficiency, which counters economic efficiency theory and implies that frontier market banks absorb higher non-performing loan costs. The findings herein support prospect theory by demonstrating that managers engage in risk-seeking behaviour while making risk-averse decisions. Overall, the study's implications suggest that banks employ alternative loan provision practices to optimise resource allocation and, by extension, performance.

8.
Polymers (Basel) ; 13(20)2021 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-34685290

RESUMO

The recyclability of opaque PET, which contains TiO2 nanoparticles, has not been as well-studied as that of transparent PET. The objective of this work is to recycle post-consumer opaque PET through reactive extrusion with Joncryl. The effect of the reactive extrusion process on the molecular structure and on the thermal/mechanical/rheological properties of recycling post-consumer opaque PET (r-PET) has been analyzed. A 1% w/w Joncryl addition caused a moderate increase in the molecular weight. A moderate increase in chain length could not explain a decrease in the overall crystallization rate. This result is probably due to the presence of branches interrupting the crystallizable sequences in reactive extruded r-PET (REX-r-PET). A rheological investigation performed by SAOS/LAOS/elongational studies detected important structural modifications in REX-r-PET with respect to linear r-PET or a reference virgin PET. REX-r-PET is characterized by a slow relaxation process with enlarged elastic behaviors that are characteristic of a long-chain branched material. The mechanical properties of REX-r-PET increased because of the addition of the chain extender without a significant loss of elongation at the break. The reactive extrusion process is a suitable way to recycle opaque PET into a material with enhanced rheological properties (thanks to the production of a chain extension and long-chain branches) with mechanical properties that are comparable to those of a typical virgin PET sample.

9.
Polymers (Basel) ; 13(14)2021 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34301021

RESUMO

Isodimorphic behavior is determined by partial inclusion of comonomer segments within the crystalline structure and arises from the comparatively similar repeating chain units of the parental homopolymers. Isodimorphic random copolymers are able to crystallize irrespective of their composition and exhibit a pseudo-eutectic behavior when their melting point values are plotted as a function of comonomer content. At the pseudo-eutectic point or region, two crystalline phases can coexist. On the right-hand and the left-hand side of the pseudo-eutectic point or region, only one single crystalline phase can form which is very similar to the crystalline structures of the parent homopolymers. This article aims to study the synthesis method, structure, crystallization behavior and mechanical properties of isodimorphic random PBS-ran-PCL copolyesters. Moreover, this study provides a comprehensive analysis of our main recent results on PBS-ran-PCL random copolyesters with three different molecular weights. The results show that the comonomer composition and crystallization conditions are the major factors responsible for the crystalline morphology, crystallization kinetics and mechanical performance of isodimorphic random copolyesters. Our studies demonstrate that in the pseudo-eutectic region, where both crystalline phases can coexist, the crystallization conditions determine the crystalline phase or phases of the copolymer. The relationships between the comonomer composition and mechanical properties are also addressed in this work.

10.
Mol Cancer Ther ; 20(8): 1422-1430, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34108263

RESUMO

The peripheral T-cell lymphomas (PTCL) could be considered the prototypical epigenetic disease. As a disease, they are uniquely sensitive to histone deacetylase (HDAC) and DNA methyltransferase (DNMT) inhibitors, both alone and in combination, are characterized by a host of mutations in epigenetic genes, and can develop spontaneously in genetically engineered murine models predicated on established recurring mutations in (RHOAG17V) and TET2, an epigenetic gene governing DNA methylation. Given the clinical benefit of HDAC inhibitors (HDACi) and hypomethlyation agents alone and in combination in PTCL, we sought to explore a mechanistic basis for these agents in PTCL. Herein, we reveal profound class synergy between HDAC and DNMT inhibitors in PTCL, and that the combination induces degrees of gene expression that are substantially different and more extensive than that observed for the single agents. A prominent signature of the combination relates to the transcriptional induction of cancer testis antigens and genes involved in the immune response. Interestingly, TBX21 and STAT4, master regulators of TH1 differentiation, were among the genes upregulated by the combination, suggesting the induction of a TH1-like phenotype. Moreover, suppression of genes involved in cholesterol metabolism and the matrisome were also identified. We believe that these data provide a strong rationale for clinical studies, and future combinations leveraging an immunoepigenetic platform.


Assuntos
Antígenos de Neoplasias/genética , Biomarcadores Tumorais/metabolismo , Epigenoma , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Imunidade/genética , Linfoma de Células T/patologia , Testículo/metabolismo , Antimetabólitos Antineoplásicos/farmacologia , Apoptose , Azacitidina/farmacologia , Biomarcadores Tumorais/genética , Proliferação de Células , DNA (Citosina-5-)-Metiltransferase 1/antagonistas & inibidores , Metilação de DNA , Epigênese Genética , Perfilação da Expressão Gênica , Inibidores de Histona Desacetilases/farmacologia , Humanos , Linfoma de Células T/tratamento farmacológico , Linfoma de Células T/genética , Linfoma de Células T/imunologia , Masculino , Células Tumorais Cultivadas
11.
Mol Cancer Res ; 19(8): 1361-1374, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34050002

RESUMO

Histone deacetylase inhibitors (HDACi) induce hyperacetylation of histones by blocking HDAC catalytic sites. Despite regulatory approvals in hematological malignancies, limited solid tumor clinical activity has constrained their potential, arguing for better understanding of mechanisms of action (MOA). Multiple activities of HDACis have been demonstrated, dependent on cell context, beyond the canonical induction of gene expression. Here, using a clinically relevant exposure duration, we established DNA damage as the dominant signature using the NCI-60 cell line database and then focused on the mechanism by which hyperacetylation induces DNA damage. We identified accumulation of DNA-RNA hybrids (R-loops) following romidepsin-induced histone hyperacetylation, with single-stranded DNA (ssDNA) breaks detected by single-cell electrophoresis. Our data suggest that transcription-coupled base excision repair (BER) is involved in resolving ssDNA breaks that, when overwhelmed, evolve to lethal dsDNA breaks. We show that inhibition of BER proteins such as PARP will increase dsDNA breaks in this context. These studies establish accumulation of R-loops as a consequence of romidepsin-mediated histone hyperacetylation. We believe that the insights provided will inform design of more effective combination therapy with HDACis for treatment of solid tumors. IMPLICATIONS: Key HDAC inhibitor mechanisms of action remain unknown; we identify accumulation of DNA-RNA hybrids (R-loops) due to chromatin hyperacetylation that provokes single-stranded DNA damage as a first step toward cell death.


Assuntos
DNA de Cadeia Simples/efeitos dos fármacos , Depsipeptídeos/farmacologia , Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/metabolismo , Estruturas R-Loop/efeitos dos fármacos , Acetilação/efeitos dos fármacos , Linhagem Celular Tumoral , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/genética , Reparo do DNA/efeitos dos fármacos , Reparo do DNA/genética , DNA de Cadeia Simples/genética , Humanos , Células PC-3 , Estruturas R-Loop/genética
12.
Infect Disord Drug Targets ; 21(8): e211221191975, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33653256

RESUMO

INTRODUCTION: COVID-19 has caused a great deal of fear in different communities. In this study, we reported the recovery of a diabetic elderly woman with a history of asthma from COVID-19 infection. CASE PRESENTATION: A 61-year-old woman was hospitalized due to dyspnea and low blood O2 saturation and was later diagnosed with COVID-19, as confirmed by PCR. The patient had a history of asthma and diabetes and used salbutamol and Atrovent spray. She also had a history of hospitalization at one month prior to the current admission. Despite all these, COVID-19 was successfully managed, and she was discharged with a good clinical condition after the improvement of respiratory complications. CONCLUSION: Despite having an advanced age and underlying diseases (diabetes and asthma), the recovery of this elderly woman shows that even such patientscandefeatCOVID-19 as long as the disease is not progressed to advanced phases and appropriate therapeutic measures are taken. By reporting such cases, it is possible to give people hope and motivation and reduce their fear of the disease.


Assuntos
Asma , COVID-19 , Diabetes Mellitus , Idoso , Asma/complicações , Asma/tratamento farmacológico , Feminino , Hospitalização , Humanos , Pessoa de Meia-Idade , SARS-CoV-2
13.
Sci Rep ; 10(1): 12068, 2020 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-32694704

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

14.
Polymers (Basel) ; 12(1)2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31861773

RESUMO

In this work, we study for the first time, the isothermal crystallization behavior of isodimorphic random poly(butylene succinate)-ran-poly(ε-caprolactone) copolyesters, PBS-ran-PCL, previously synthesized by us. We perform nucleation and spherulitic growth kinetics by polarized light optical microscopy (PLOM) and overall isothermal crystallization kinetics by differential scanning calorimetry (DSC). Selected samples were also studied by real-time wide angle X-ray diffraction (WAXS). Under isothermal conditions, only the PBS-rich phase or the PCL-rich phase could crystallize as long as the composition was away from the pseudo-eutectic point. In comparison with the parent homopolymers, as comonomer content increased, both PBS-rich and PCL-rich phases nucleated much faster, but their spherulitic growth rates were much slower. Therefore, the overall crystallization kinetics was a strong function of composition and supercooling. The only copolymer with the eutectic composition exhibited a remarkable behavior. By tuning the crystallization temperature, this copolyester could form either a single crystalline phase or both phases, with remarkably different thermal properties.

15.
Langmuir ; 35(47): 15168-15179, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31621336

RESUMO

This work describes the successful melt infiltration of poly(butylene succinate) (PBS) and poly(butylene adipate) (PBA) within 70 nm diameter anodic aluminum oxide (AAO) templates. The infiltrated samples were characterized by SEM, Raman, and FTIR spectroscopy. The crystallization behaviors and crystalline structures of both polymers, bulk and confined, were analyzed by differential scanning calorimetry (DSC) and grazing incidence wide angle X-ray scattering (GIWAXS). DSC revealed that a change in the nucleation process occurred from heterogeneous nucleation for bulk samples to homogeneous nucleation for infiltrated PBA and to surface-induced nucleation for infiltrated PBS. GIWAXS results indicate that PBS nanofibers crystallize in the α-phase, as well as their bulk samples. However, PBA nanofibers crystallize just in the ß-phase, whereas PBA bulk samples crystallize in a mixture of α- and ß-phases. The crystal orientation within the pores was determined, and differences between PBS and PBA were also found. Finally, broadband dielectric spectroscopy was applied to study the segmental dynamics for bulk and infiltrated samples. The glass temperature was found to significantly decrease in the PBS case upon infiltration, while that of PBA remained unchanged. These differences were correlated with the higher affinity of PBS to the AAO walls than PBA, in accordance with their nucleation behavior (surface-induced versus homogeneous nucleation, respectively).

16.
Sci Rep ; 9(1): 12736, 2019 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-31484962

RESUMO

Environmental contamination with aromatic compounds is a universal challenge. Aromatic-degrading microorganisms isolated from the same or similar polluted environments seem to be more suitable for bioremediation. Moreover, microorganisms adapted to contaminated environments are able to use toxic compounds as the sole sources of carbon and energy. An indigenous strain of Pseudomonas, isolated from the Mahshahr Petrochemical plant in the Khuzestan province, southwest of Iran, was studied genetically. It was characterized as a novel Gram-negative, aerobic, halotolerant, rod-shaped bacterium designated Pseudomonas YKJ, which was resistant to chloramphenicol and ampicillin. Genome of the strain was completely sequenced using Illumina technology to identify its genetic characteristics. MLST analysis revealed that the YKJ strain belongs to the genus Pseudomonas indicating the highest sequence similarity with Pseudomonas pseudoalcaligenes strain CECT 5344 (99% identity). Core- and pan-genome analysis indicated that P. pseudoalcaligenes contains 1,671 core and 3,935 unique genes for coding DNA sequences. The metabolic and degradation pathways for aromatic pollutants were investigated using the NCBI and KEGG databases. Genomic and experimental analyses showed that the YKJ strain is able to degrade certain aromatic compounds including bisphenol A, phenol, benzoate, styrene, xylene, benzene and chlorobenzene. Moreover, antibiotic resistance and chemotaxis properties of the YKJ strain were found to be controlled by two-component regulatory systems.


Assuntos
Fenóis/metabolismo , Pseudomonas pseudoalcaligenes/genética , Pseudomonas pseudoalcaligenes/metabolismo , Antibacterianos/farmacologia , Biodegradação Ambiental , Farmacorresistência Bacteriana , Genoma Bacteriano , Genômica , Irã (Geográfico) , Fenóis/química , Filogenia , Pseudomonas pseudoalcaligenes/efeitos dos fármacos , Pseudomonas pseudoalcaligenes/isolamento & purificação , Poluentes do Solo/química , Poluentes do Solo/metabolismo
17.
Dent J (Basel) ; 7(3)2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31374979

RESUMO

Midwifery students can have an important role in transferring oral health care information to expecting mothers. The aim of this study was to assess the effect of an educational intervention on knowledge and attitudes of midwifery students on oral health in pregnancy. Study population consisted of 60 midwifery students in a Midwifery School in Iran who were randomly allocated into case and control groups. Self-administered questionnaires were distributed before, immediately after the intervention and also three months later. The validity and reliability of the questionnaire was confirmed at the beginning. Mean total pre-test knowledge scores from total 10 in the interventional and control groups were 4.63 ± 0.25 (Standard Error, SE) and 4.79 ± 0.31 (SE) respectively. After three months scores reached to 8.87 ± 0.15 (SE) in the interventional and 5.57 ± 0.29 (SE) in the control groups. Mean attitude pre-test scores in the interventional group was 27.23 ± 0.75 (SE) and after the intervention reached to 31.13 ± 0.25 (SE). Lecture-based educational intervention improved the knowledge and attitudes of midwifery students on oral health care in pregnancy. Incorporating courses on oral health in pregnancy into the curricula of midwifery programs can be effective in promoting oral health care in pregnant women.

18.
Curr Hematol Malig Rep ; 14(4): 219-227, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31231778

RESUMO

PURPOSE OF REVIEW: To highlight recent results in targeting mRNA translation and discuss the results and prospects of translation inhibitors in cancer therapy. RECENT FINDINGS: Until recently, inhibitors of mRNA translation have been thought to likely lack a therapeutic window. In 2012, the Food and Drug Administration (FDA) approved omacetaxine mepesuccinate (homoharringtonine) for the treatment of adults with chronic myelogenous leukemia (CML) who are resistant to at least two tyrosine kinase inhibitors. Since then, a few drugs, notably tomivosertib (eFT-508), selinexor (KPT-330), and ribavirin, have entered clinical trials. These drugs are known to inhibit mRNA translation. More recently, a number of interesting studies report that discrete subsets of proteins in cancer cells may be selectively targeted at the translation step, through inhibiting signals such as phospho-4E-BP1, eIF4A, and eIF4E. Promising therapies using these strategies have demonstrated potent anti-tumor activity in preclinical cancer models. The growing number of translation inhibitors with diverse mechanisms, coupled with emerging insights into translational regulation of different cancer-promoting genes, suggests a bright new horizon for the field of therapeutic targeting of mRNA translation in cancer.


Assuntos
Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Neoplasias/genética , Biossíntese de Proteínas/efeitos dos fármacos , RNA Mensageiro/genética , Animais , Biomarcadores , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias/metabolismo , Transdução de Sinais/efeitos dos fármacos
19.
J Tissue Eng Regen Med ; 12(1): e495-e512, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-27689781

RESUMO

Cardiac tissue engineering (CTE) is currently a prime focus of research because of an enormous clinical need. In the present work, a novel functional material, poly(3-hydroxyoctanoate), P(3HO), a medium chain-length polyhydroxyalkanoate (PHA), produced using bacterial fermentation, was studied as a new potential material for CTE. Engineered constructs with improved mechanical properties, crucial for supporting the organ during new tissue regeneration, and enhanced surface topography, to allow efficient cell adhesion and proliferation, were fabricated. Results showed that the mechanical properties of the final patches were close to that of cardiac muscle. Biocompatibility of neat P(3HO) patches, assessed using neonatal ventricular rat myocytes (NVRM), showed that the polymer was as good as collagen in terms of cell viability, proliferation and adhesion. Enhanced cell adhesion and proliferation properties were observed when porous and fibrous structures were incorporated into the patches. In addition, no deleterious effect was observed on adult cardiomyocyte contraction when cardiomyocytes were seeded on the P(3HO) patches. Hence, P(3HO)-based multifunctional cardiac patches are promising constructs for efficient CTE. This work will have a positive impact on the development of P(3HO) and other PHAs as a novel new family of biodegradable functional materials with huge potential in a range of different biomedical applications, particularly CTE, leading to further interest and exploitation of these materials. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Caprilatos/farmacologia , Coração/fisiologia , Teste de Materiais , Engenharia Tecidual/métodos , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Coração/efeitos dos fármacos , Camundongos , Contração Miocárdica/efeitos dos fármacos , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Ratos , Temperatura , Fator A de Crescimento do Endotélio Vascular/metabolismo
20.
Sci Rep ; 7(1): 15610, 2017 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-29142289

RESUMO

In this study, we provide a comparative genomic analysis of Pantoea agglomerans strain P5 and 10 closely related strains based on phylogenetic analyses. A next-generation shotgun strategy was implemented using the Illumina HiSeq 2500 technology followed by core- and pan-genome analysis. The genome of P. agglomerans strain P5 contains an assembly size of 5082485 bp with 55.4% G + C content. P. agglomerans consists of 2981 core and 3159 accessory genes for Coding DNA Sequences (CDSs) based on the pan-genome analysis. Strain P5 can be grouped closely with strains PG734 and 299 R using pan and core genes, respectively. All the predicted and annotated gene sequences were allocated to KEGG pathways. Accordingly,  genes involved in plant growth-promoting (PGP) ability, including phosphate solubilization, IAA and siderophore production, acetoin and 2,3-butanediol synthesis and bacterial secretion, were assigned. This study provides an in-depth view of the PGP characteristics of strain P5, highlighting its potential use in agriculture as a biofertilizer.


Assuntos
Genoma Bacteriano/genética , Genômica , Pantoea/genética , Doenças das Plantas/genética , Hibridização Genômica Comparativa , Redes Reguladoras de Genes/genética , Anotação de Sequência Molecular , Filogenia , Doenças das Plantas/microbiologia , Sequenciamento Completo do Genoma
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