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1.
Nat Commun ; 15(1): 536, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38225282

RESUMO

Rechargeable lithium batteries using 5 V positive electrode materials can deliver considerably higher energy density as compared to state-of-the-art lithium-ion batteries. However, their development remains plagued by the lack of electrolytes with concurrent anodic stability and Li metal compatibility. Here we report a new electrolyte based on dimethyl 2,5-dioxahexanedioate solvent for 5 V-class batteries. Benefiting from the particular chemical structure, weak interaction with lithium cation and resultant peculiar solvation structure, the resulting electrolyte not only enables stable, dendrite-free lithium plating-stripping, but also displays anodic stability up to 5.2 V (vs. Li/Li+), in additive or co-solvent-free formulation, and at low salt concentration of 1 M. Consequently, the Li | |LiNi0.5Mn1.5O4 cells using the 1 M LiPF6 in 2,5-dioxahexanedioate based electrolyte retain >97% of the initial capacity after 250 cycles, outperforming the conventional carbonate-based electrolyte formulations, making this, and potentially other dicarbonate solvents promising for future Lithium-based battery practical explorations.

2.
Rev Esp Enferm Dig ; 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38235679

RESUMO

A 65-year-old man was admitted to our hospital complaining of reflux for more than 20 years. After endoscopy and barium-swallow examination, he was diagnosed with achalasia as well as a squamous cell carcinoma. Therefore, peroral endoscopic myotomy (POEM) combined with endoscopic submucosal dissection (ESD) was performed simultaneously. During the procedure, a mucosal erosion with a clear boundary was shown in the middle segment of the esophagus. ESD was first performed and the lesion was removed en-bloc. Subsequent POEM therapy was performed after marking the left esophageal wall 10cm above the cardia. After submucosal injection, the submucosal plane was created through a length 2cm longitudinal incision, then the muscle was cut a length of 10 cm into the esophagus and 2 cm below the cardia, and finally the incision was closed by clips. Pathological examination revealed high-grade intraepithelial neoplasia of squamous epithelium (carcinoma in situ) with a negative margin. The patient was recovered without complication four days after the procedure. The endoscopy showed perfect healing of the esophageal lesions during two-months follow-up , and the reflux symptom was resolved.

3.
Nanomaterials (Basel) ; 13(19)2023 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-37836362

RESUMO

Studying the mechanisms of the spin Hall effect (SHE) is essential for the fundamental understanding of spintronic physics. By now, despite the intensive studies of SHE on heavy metal (HM)/metallic magnet heterostructures, the SHE on HM/ferrimagnetic insulator (FMI) heterostructures still remains elusive. Here, we study the mechanism of SHE in the Pt/Tm3Fe5O12 (TmIG) heterostructure. We first tune the crystallinity and resistivity of Pt by an annealing method, and then study the spin-orbit torque (SOT) in the tuned-Pt/TmIG devices. The SOT generation efficiency per unit electric field and spin Hall angle were obtained, which are insensitive to the annealing temperature. We further demonstrate that the intrinsic contribution in the moderately dirty regime is responsible for the SHE in our Pt/TmIG bilayer. Our study provides an important piece of information for the SHE in FMI-based spintronic physics.

4.
World J Gastrointest Surg ; 15(3): 440-449, 2023 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-37032804

RESUMO

BACKGROUND: Endoscopic resection remains an effective method for the treatment of small rectal neuroendocrine tumors (NETs) (≤ 10 mm). Moreover, endoscopic mucosal resection (EMR) with double band ligation (EMR-dB), a simplified modification of EMR with band ligation, is an alternative strategy to remove small rectal NETs. AIM: To evaluate the feasibility and safety of EMR-dB for the treatment of small rectal NETs (≤ 10 mm). METHODS: A total of 50 patients with small rectal NETs, without regional lymph node enlargement or distant metastasis confirmed by endoscopic ultrasound, computerized tomography scan, or magnetic resonance imaging, were enrolled in the study from March 2021 to June 2022. These patients were randomly assigned into the EMR-dB (n = 25) group or endoscopic submucosal dissection (ESD) group (n = 25). The characteristics of the patients and tumors, procedure time, devices cost, complete resection rate, complications, and recurrence outcomes were analyzed. RESULTS: There were 25 patients (13 males, 12 females; age range 28-68 years old) in the EMR-dB group, and the ESD group contained 25 patients (15 males, 10 females; age range 25-70 years old). Both groups had similar lesion sizes (EMR-dB 4.53 ± 1.02 mm, ESD 5.140 ± 1.74 mm; P = 0.141) and resected lesion sizes(1.32 ± 0.52 cm vs 1.58 ± 0.84 cm; P = 0.269). Furthermore, the histological complete resection and en bloc resection rates were achieved in all patients (100% for each). In addition, there was no significant difference in the complication rate between the two groups. However, the procedure time was significantly shorter and the devices cost was significantly lower in the EMR-dB group. Besides, there was no recurrence in both groups during the follow-up period. CONCLUSION: The procedure time of EMR-dB was shorter compared with ESD, and both approaches showed a similar curative effect. Taken together, EMR-dB was a feasible and safe option for the treatment of small rectal NETs.

5.
ACS Appl Mater Interfaces ; 15(16): 20166-20174, 2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37058326

RESUMO

Nanoreactors consisting of hydrophilic porous SiO2 shells and amphiphilic copolymer cores have been prepared, which can easily self-tune their hydrophilic/hydrophobic balance depending on the environment and exhibit chameleon-like behavior. The accordingly obtained nanoparticles show excellent colloidal stability in a variety of solvents with different polarity. Most importantly, thanks to the assistance of the nitroxide radicals attached to the amphiphilic copolymers, the synthesized nanoreactors show high catalytic activity for model reactions in both polar and nonpolar environments and, more particularly, realize a high selectivity for the products resulting from the oxidation of benzyl alcohol in toluene.

6.
Oxid Med Cell Longev ; 2022: 8543720, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36092152

RESUMO

Background: Bioactive compound such as interleukin-22 (IL-22) treatment is regarded as a sufficient treatment for ulcerative colitis (UC). It has been found that long noncoding RNAs (lncRNAs) expressed in many inflammatory diseases, including UC. We aimed to verify the treatment effect of bioactive compounds including IL-22 and lncRNAs in UC on colitis mice. Methods: UC mice were induced using DSS, followed by IL-22 or PBS intraperitoneally (i.p.) injection. Then, the histopathological parameters of the mice were determined. Then, RNA sequencing was performed to screen the differential lncRNAs. Quantitative real-time PCR (qRT-PCR) and lentivirus identified lncRNA-Ulcerative Colitis lncRNA (lncRNA-UCL) were regarded as the molecular regulator of the colitis mice. The correlation with lncRNA-UCL and mmu-miR-568 was validated using RNA-pulldown. Meanwhile, claudin-1 was predicted and confirmed as the target molecule of mmu-miR-568 using dual-luciferase assay. Results: IL-22 could significantly improve the histopathological features and decrease proinflammatory cytokine production in UC mice induced by DSS. It also can stimulate intestinal epithelial cell (IEC) reproduction and prevention of apoptosis. lncRNA-UCL was significantly downregulated in UC mice caused by DSS, while IL-22 treatment effectively reversed this effect. In terms of mechanism, lncRNA-UCL regulates intestinal epithelial homeostasis by sequestering mmu-miR-568 and maintaining close integrated protein expression, such as claudin-1. Conclusions: We have demonstrated the incredible role of bioactive compound, such as IL-22, in alleviating DSS-induced colitis symptoms via enhancing lncRNA-UCL expression. It can be regulated using tight junction (TJ) protein.


Assuntos
Claudina-1 , Colite , Interleucinas , MicroRNAs , RNA Longo não Codificante , Animais , Claudina-1/biossíntese , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colite/genética , Colite/metabolismo , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/tratamento farmacológico , Colite Ulcerativa/genética , Sulfato de Dextrana/toxicidade , Interleucinas/farmacologia , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Proteínas de Junções Íntimas/metabolismo , Regulação para Cima , Interleucina 22
7.
Front Aging Neurosci ; 13: 762659, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34867289

RESUMO

Amyloid-ß, a hallmark of Alzheimer's disease, forms toxic intracellular oligomers and extracellular senile plaques resulting in neuronal toxicity. Ethanol is widely consumed worldwide. Moderate ethanol consumption has numerous benefits in humans. We found that ethanol could significantly extend the lifespan of Caenorhabiditis elegans in a previous study. Based on that study, we tested the effect of ethanol on Alzheimer's disease transgenic Caenorhabiditis elegans strain CL4176, which expresses amyloid-ß1-42 peptide in body wall muscle cells. Ethanol delayed paralysis and reduced amyloid-ß oligomers in Caenorhabiditis elegans worms of the CL4176 strain. Moreover, ethanol could induce the nuclear translocation of DAF-16 in the nematodes. However, in worms that were fed daf-16 RNAi bacteria, ethanol no longer delayed the paralysis. The qPCR assays showed that ethanol increases the expression of daf-16, hsf-1 and their common target genes- small heat shock protein genes. In addition, we also found that ethanol could increase lysosome mass in the CL4176 worms. In summary, our study indicated that ethanol attenuated amyloid-ß toxicity in the Alzheimer's disease model of Caenorhabiditis elegans via increasing the level of lysosomes to promote amyloid-ß degradation and upregulating the levels of small heat shock protein genes to reduce amyloid-ß aggregation.

8.
Nanomaterials (Basel) ; 11(11)2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34835536

RESUMO

Electrical spin-orbit torque (SOT) in magnetic insulators (MI) has been intensively studied due to its advantages in spin-orbitronic devices with ultralow energy consumption. However, the magnon torque in the MIs, which has the potential to further lower the energy consumption, still remains elusive. In this work, we demonstrate the efficient magnon torque transferred into an MI through an antiferromagnetic insulator. By fabricating a Pt/NiO/Tm3Fe5O12 heterostructure with different NiO thicknesses, we have systematically investigated the evolution of the transferred magnon torque. We show that the magnon torque efficiency transferred through the NiO into the MI can retain a high value (∼50%), which is comparable to the previous report for the magnon torque transferred into the metallic magnet. Our study manifests the feasibility of realizing the pure magnon-based spin-orbitronic devices with ultralow energy consumption and high efficiency.

9.
Front Chem ; 8: 238, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32373578

RESUMO

We report a new sensor for the specific detection of lead ions (Pb2+) in contaminated water based on fluorescence resonance energy transfer (FRET) between upconversion nanoparticles (UCNPs) as donors and gold nanoparticles (Au NPs) as receptors. The UCNPs modified with Pb2+ aptamers could bind to Au NPs, which were functionalized with complementary DNA through hybridization. The green fluorescence of UCNPs was quenched to a maximum rate of 80% due to the close proximity between the energy donor and the acceptor. In the presence of Pb2+, the FRET process was broken because Pb2+ induced the formation of G-quadruplexes from aptamers, resulting in unwound DNA duplexes and separated acceptors from donors. The fluorescence of UCNPs was restored, and the relative intensity had a significant linear correlation with Pb2+ concentration from 0 to 50 nM. The sensor had a detection limit as low as 4.1 nM in a buffer solution. More importantly, the sensor exhibited specific detection of Pb2+ in complex metal ions, demonstrating high selectivity in practical application. The developed FRET prober may open up a new insight into the specific detection of environmental pollution.

10.
Medicine (Baltimore) ; 99(11): e19388, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32176063

RESUMO

BACKGROUND: This meta-analysis focuses on the controversial efficacy and safety of platelet-rich plasma (PRP) as compared with hyaluronic acid (HA) in the clinical treatment of knee osteoarthritis. We have attempted to provide an evidence-based medicine protocol for the conservative treatment of knee osteoarthritis. In addition, we included the latest relevant literature in this meta-analysis, and a staging study was conducted to compare the therapeutic effects of PRP and HA for knee osteoarthritis over different time periods. METHODS: An online computer search with "platelet-rich plasma" and "knee osteoarthritis" as search terms was conducted in the PubMed, EMBASE, and Cochrane Library databases. We conducted a quality assessment of the retrieved literature and extracted the following indicators: visual analog scale (VAS) score, subjective International Knee Documentation Committee (IKDC) score, Western Ontario and McMaster Universities (WOMAC) score, Knee Injury and Osteoarthritis Outcome Score (KOOS), and adverse events. RevMan5.3 software was used to determine the effect sizes, and indicators were compared across studies at three different time points from the administration of treatment. RESULTS: A total of 14 randomized controlled trials (RCTs) involving 1350 patients were included. Long-term VAS, IKDC, WOMAC-Pain, WOMAC-Stiffness, WOMAC-Physical Function, and WOMAC-Total scores at each time point were higher in the PRP group than in the HA group. There were no significant differences in the remaining indicators between the two groups. CONCLUSION: Compared with HA, PRP offers obvious advantages in the conservative treatment of knee osteoarthritis. Treatment with PRP can reduce long-term pain and improve knee joint function with no additional risks. Therefore, PRP can be widely used for the conservative treatment of knee osteoarthritis.


Assuntos
Tratamento Conservador/métodos , Ácido Hialurônico/uso terapêutico , Osteoartrite do Joelho/diagnóstico , Osteoartrite do Joelho/terapia , Plasma Rico em Plaquetas , Amplitude de Movimento Articular/efeitos dos fármacos , Feminino , Humanos , Injeções Intra-Articulares , Masculino , Medição da Dor , Prognóstico , Amplitude de Movimento Articular/fisiologia , Medição de Risco , Índice de Gravidade de Doença , Resultado do Tratamento , Viscossuplementos/uso terapêutico
11.
Int J Infect Dis ; 85: 167-174, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31202908

RESUMO

OBJECTIVE: The nucleic acid-based polymerase chain reaction (PCR) assay is commonly applied to detect infection with Zika virus (ZIKV). However, the time- and labor-intensive sample pretreatment required to remove inhibitors that cause false-negative results in clinical samples is impractical for use in resource-limited areas. The aim was to develop a direct reverse-transcription quantitative PCR (dirRT-qPCR) assay for ZIKV diagnosis directly from clinical samples. METHODS: The combination of inhibitor-tolerant polymerases, polymerase enhancers, and dirRT-qPCR conditions was optimized for various clinical samples including blood and serum. Sensitivity was evaluated with standard DNA spiked in simulated samples. Specificity was evaluated using clinical specimens of other infections such as dengue virus and chikungunya virus. RESULTS: High specificity and sensitivity were achieved, and the limit of detection (LOD) of the assay was 9.5×101 ZIKV RNA copies/reaction. The on-site clinical diagnosis of ZIKV required a 5µl sample and the diagnosis could be completed within 2h. CONCLUSIONS: This robust dirRT-qPCR assay shows a high potential for point-of-care diagnosis, and the primer-probe combinations can also be extended for other viral detection. It realizes the goal of large-scale on-site screening for viral infections and could be used for early diagnosis and the prevention and control of viral outbreaks.


Assuntos
Reação em Cadeia da Polimerase Via Transcriptase Reversa , Infecção por Zika virus/diagnóstico , Zika virus/isolamento & purificação , Adulto , Criança , Feminino , Humanos , Limite de Detecção , Masculino , RNA Viral/análise , RNA Viral/sangue , Sensibilidade e Especificidade , Zika virus/genética
12.
ACS Appl Mater Interfaces ; 11(4): 3861-3868, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30605308

RESUMO

Issues of uniform incorporation of catalytic functional species with controllable sizes, shapes, compositions, and functions into porous carbon scaffolds remain significant challenges toward enriching and boosting performance. Here, we develop a straightforward approach that introduces dicyandiamide as a nitrogen source to chelate with metal species and combines with the surfactant-templating self-assembly method for the fabrication of highly dispersed catalysts anchored in nitrogen-containing ordered mesoporous carbon (NOMC). As a result, these functional catalyst (such as PdCu nanocrystals)-embedded NOMC composites manifest a synergistic catalytic capability for the electroreduction of nitrate in neutral electrolyte, with more than 90% nitrate removed under an ultra-low concentration of 100 ppm and a high nitrogen selectivity of 60% after 10 repeated tests.

13.
J Pharmacol Exp Ther ; 343(3): 617-27, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22935731

RESUMO

ABT-348 [1-(4-(4-amino-7-(1-(2-hydroxyethyl)-1H-pyrazol-4-yl)thieno[3,2-c]pyridin-3-yl)phenyl)-3-(3-fluorophenyl)urea] is a novel ATP-competitive multitargeted kinase inhibitor with nanomolar potency (IC(50)) for inhibiting binding and cellular autophosphorylation of Aurora B (7 and 13 nM), C (1 and 13 nM), and A (120 and 189 nM). Cellular activity against Aurora B is reflected by inhibition of phosphorylation of histone H3, induction of polyploidy, and inhibition of proliferation of a variety of leukemia, lymphoma, and solid tumor cell lines (IC(50) = 0.3-21 nM). In vivo inhibition of Aurora B was confirmed in an engrafted leukemia model by observing a decrease in phosphorylation of histone H3 that persisted in a dose-dependent manner for 8 h and correlated with plasma concentration of ABT-348. Evaluation of ABT-348 across a panel of 128 kinases revealed additional potent binding activity (K(i) < 30 nM) against vascular endothelial growth factor receptor (VEGFR)/platelet-derived growth factor receptor (PDGFR) families and the Src family of cytoplasmic tyrosine kinases. VEGFR/PDGFR binding activity correlated with inhibition of autophosphorylation in cells and inhibition of vascular endothelial growth factor (VEGF)-stimulated endothelial cell proliferation (IC(50) ≤ 0.3 nM). Evidence of on-target activity in vivo was provided by the potency for blocking VEGF-mediated vascular permeability and inducing plasma placental growth factor. Activity against the Src kinase family was evident in antiproliferative activity against BCR-ABL chronic myeloid leukemia cells and cells expressing the gleevec-resistant BCR-ABL T315I mutation. On the basis of its unique spectrum of activity, ABT-348 was evaluated and found effective in representative solid tumor [HT1080 and pancreatic carcinoma (MiaPaCa), tumor stasis] and hematological malignancy (RS4;11, regression) xenografts. These results provide the rationale for clinical assessment of ABT-348 as a therapeutic agent in the treatment of cancer.


Assuntos
Aminopiridinas/farmacologia , Antineoplásicos/farmacologia , Compostos de Fenilureia/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Receptores do Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Quinases da Família src/antagonistas & inibidores , Aminopiridinas/química , Aminopiridinas/farmacocinética , Aminopiridinas/uso terapêutico , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapêutico , Aurora Quinase B , Aurora Quinases , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Feminino , Histonas/antagonistas & inibidores , Células Endoteliais da Veia Umbilical Humana , Humanos , Leucemia Experimental/tratamento farmacológico , Leucemia Experimental/enzimologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos SCID , Estrutura Molecular , Células NIH 3T3 , Compostos de Fenilureia/química , Compostos de Fenilureia/farmacocinética , Compostos de Fenilureia/uso terapêutico , Fatores de Tempo , Ensaios Antitumorais Modelo de Xenoenxerto
15.
J Biol Chem ; 286(51): 43951-43958, 2011 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-22020937

RESUMO

Eukaryotic elongation factor-2 kinase (eEF2K) relays growth and stress signals to protein synthesis through phosphorylation and inactivation of eukaryotic elongation factor 2 (eEF2). 1-Benzyl-3-cetyl-2-methylimidazolium iodide (NH125) is a widely accepted inhibitor of mammalian eEF2K and an efficacious anti-proliferation agent against different cancer cells. It implied that eEF2K could be an efficacious anticancer target. However, eEF2K siRNA was ineffective against cancer cells including those sensitive to NH125. To test if pharmacological intervention differs from siRNA interference, we identified a highly selective small molecule eEF2K inhibitor A-484954. Like siRNA, A-484954 had little effect on cancer cell growth. We carefully examined the effect of NH125 and A-484954 on phosphorylation of eEF2, the known cellular substrate of eEF2K. Surprisingly, NH125 increased eEF2 phosphorylation, whereas A-484954 inhibited the phosphorylation as expected for an eEF2K inhibitor. Both A-484954 and eEF2K siRNA inhibited eEF2K and reduced eEF2 phosphorylation with little effect on cancer cell growth. These data demonstrated clearly that the anticancer activity of NH125 was more correlated with induction of eEF2 phosphorylation than inhibition of eEF2K. Actually, induction of eEF2 phosphorylation was reported to correlate with inhibition of cancer cell growth. We compared several known inducers of eEF2 phosphorylation including AMPK activators and an mTOR inhibitor. Interestingly, stronger induction of eEF2 phosphorylation correlated with more effective growth inhibition. We also explored signal transduction pathways leading to NH125-induced eEF2 phosphorylation. Preliminary data suggested that NH125-induced eEF2 phosphorylation was likely mediated through multiple pathways. These observations identified an opportunity for a new multipathway approach to anticancer therapies.


Assuntos
Regulação Neoplásica da Expressão Gênica , Imidazóis/farmacologia , Fator 2 de Elongação de Peptídeos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células , Desenho de Fármacos , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Fosforilação , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , eIF-2 Quinase/metabolismo
17.
Bioorg Med Chem Lett ; 17(23): 6499-504, 2007 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-17931867

RESUMO

A variety of macrocyclic urea compounds were prepared as potent Chk1 inhibitors by modifying the C5 position of the benzene ring of the macrocyclic urea with ether moieties, aliphatic carbon chains, amide and halides. Enzymatic activity less than 20nM was observed in 29 of 40 compounds. Compounds 14, 46d, and 48j provided the best overall results in the cellular assays as they abrogated doxorubicin-induced cell cycle arrest (IC(50)=3.31, 3.08, and 3.13microM) and enhanced doxorubicin cytotoxicity (IC(50)=0.54, 1.27, and 0.96microM) while displaying no single agent activity, respectively.


Assuntos
Compostos Macrocíclicos/síntese química , Inibidores de Proteínas Quinases/síntese química , Proteínas Quinases/metabolismo , Ureia/síntese química , Linhagem Celular Tumoral , Quinase 1 do Ponto de Checagem , Células HeLa , Humanos , Compostos Macrocíclicos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Relação Estrutura-Atividade , Ureia/farmacologia
18.
Bioorg Med Chem Lett ; 17(23): 6593-601, 2007 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-17935989

RESUMO

A new series of potent macrocyclic urea-based Chk1 inhibitors are described. A detailed SAR study on the 4-position of the phenyl ring of the 14-member macrocyclic ureas 1a and d led to the identification of the potent Chk1 inhibitors 2, 5-7, 10, 13, 14, 19-21, 25, 27, and 31-34. These compounds significantly sensitize tumor cells to the DNA-damaging antitumor agent doxorubicin in a cell-based assay and efficiently abrogate the doxorubicin-induced G2/M and camptothecin-induced S checkpoints, indicating that the potent biological activities of these compounds are mechanism-based through Chk1 inhibition. Kinome profiling analysis of a representative macrocyclic urea 25 against a panel of 120 kinases indicates that these novel macrocyclic ureas are highly selective Chk1 inhibitors. Preliminary PK studies of 1a and b suggest that the 14-member macrocyclic inhibitors may possess better PK properties than their 15-member counterparts. An improved synthesis of 2 and 20 by using 2-(trimethylsilyl)ethoxycarbonyl (Teoc) to protect the amino group not only readily provided the desired compounds in pure form but also facilitated the scale up of potent compounds for various biological studies.


Assuntos
Compostos Macrocíclicos/síntese química , Compostos Macrocíclicos/farmacocinética , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacocinética , Proteínas Quinases , Ureia/síntese química , Ureia/farmacocinética , Animais , Catálise , Quinase 1 do Ponto de Checagem , Células HeLa , Humanos , Compostos Macrocíclicos/farmacologia , Camundongos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Quinases/farmacocinética , Proteínas Quinases/fisiologia , Relação Estrutura-Atividade , Ureia/farmacologia
19.
Bioorg Med Chem Lett ; 17(20): 5665-70, 2007 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-17768051

RESUMO

A series of 1,4-dihydroindeno[1,2-c]pyrazole compounds with a cyanopyridine moiety at the 3-position of the tricyclic pyrazole core was explored as potent CHK-1 inhibitors. The impact of substitutions at the 6 and/or 7-position of the core on pharmacokinetic properties was studied in detail. Compounds carrying a side chain with an ether linker at the 7-position and a terminal morpholino group, such as 29 and 30, exhibited much-improved oral biovailability in mice as compared to earlier generation inhibitors. These compounds also possessed desirable cellular activity in potentiating doxorubicin and will serve as valuable tool compounds for in vivo evaluation of CHK-1 inhibitors to sensitize DNA-damaging agents.


Assuntos
Hidrogênio/química , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Proteínas Quinases/metabolismo , Pirazóis/química , Pirazóis/farmacologia , Piridinas/química , Administração Oral , Animais , Quinase 1 do Ponto de Checagem , Cianetos/química , Indenos/química , Concentração Inibidora 50 , Camundongos , Estrutura Molecular , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/síntese química , Pirazóis/administração & dosagem , Pirazóis/síntese química , Ratos , Relação Estrutura-Atividade
20.
Bioorg Med Chem Lett ; 17(21): 5944-51, 2007 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-17827013

RESUMO

An extensive structure-activity relationship study of the 3-position of a series of tricyclic pyrazole-based Chk1 inhibitors is described. As a result, 4'-(1,4-dihydro-indeno[1,2-c]pyrazol-3-yl)-benzonitriles (4) and 4'-(1,4-dihydro-indeno[1,2-c]pyrazol-3-yl)-pyridine-2'-carbonitriles (29) emerged as new lead series. Compared with the original lead compound 2, these new leads fully retain the biological activity in both enzymatic inhibition and cell-based assays. More importantly, the new leads 4 and 29 exhibit favorable physicochemical properties such as lower molecular weight, lower Clog P, and the absence of a hydroxyl group. Furthermore, structure-activity relationship studies were performed at the 6- and 7-positions of 4, which led to the identification of ideal Chk1 inhibitors 49, 50, 51, and 55. These compounds not only potently inhibit Chk1 in an enzymatic assay but also significantly potentiate the cytotoxicity of DNA-damaging agents in cell-based assays while they show little single agent activity. A cell cycle analysis by FACS confirmed that these Chk1 inhibitors efficiently abrogate the G2/M and S checkpoints induced by DNA-damaging agent. The current work paved the way to the identification of several potent Chk1 inhibitors with good pharmacokinetics that are suitable for in vivo study with oral dosing.


Assuntos
Nitrilas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Quinases/efeitos dos fármacos , Quinase 1 do Ponto de Checagem , Nitrilas/química , Inibidores de Proteínas Quinases/química , Relação Estrutura-Atividade
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