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1.
Exp Cell Res ; 437(1): 114007, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38499142

RESUMEN

Gastric cancer metastasis is a major cause of poor prognosis. Our previous research showed that methionine restriction (MR) lowers the invasiveness and motility of gastric carcinoma. In this study, we investigated the particular mechanisms of MR on gastric carcinoma metastasis. In vitro, gastric carcinoma cells (AGS, SNU-5, MKN7, KATO III, SNU-1, and MKN45) were grown in an MR medium for 24 h. In vivo, BALB/c mice were given a methionine-free (Met-) diet. Transwell assays were used to investigate cell invasion and migration. The amounts of Krüppel like factor 10 (KLF10) and cystathionine ß-synthase (CBS) were determined using quantitative real-time PCR and Western blot. To determine the relationship between KLF10 and CBS, chromatin immunoprecipitation and a dual-luciferase reporter experiment were used. Hematoxylin-eosin staining was used to detect lung metastasis. Liquid chromatography-mass spectrometry was used to determine cystathionine content. MR therapy had varying effects on the invasion and migration of gastric carcinoma cells AGS, SNU-5, MKN7, KATO III, SNU-1, and MKN45. KLF10 was highly expressed in AGS cells but poorly expressed in KATO III cells. KLF10 improved MR's ability to prevent gastric carcinoma cell invasion and migration. In addition, KLF10 may interact with CBS, facilitating transcription. Further detection revealed that inhibiting the KLF10/CBS-mediated trans-sulfur pathway lowered Met-'s inhibitory effect on lung metastasis development. KLF10 transcription activated CBS, accelerated the trans-sulfur pathway, and increased gastric carcinoma cells' susceptibility to MR.


Asunto(s)
Carcinoma , Neoplasias Pulmonares , Neoplasias Gástricas , Ratones , Animales , Metionina/metabolismo , Cistationina betasintasa/genética , Cistationina betasintasa/metabolismo , Neoplasias Gástricas/patología , Racemetionina , Azufre , Neoplasias Pulmonares/genética , Factores de Transcripción de Tipo Kruppel/genética , Factores de Transcripción de Tipo Kruppel/metabolismo , Factores de Transcripción de la Respuesta de Crecimiento Precoz/metabolismo
2.
J Org Chem ; 89(12): 8721-8733, 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38832808

RESUMEN

A novel strategy for the difunctionalization of electron-deficient alkenes with aryl sulfonium salts to access remote sulfur-containing oxindole derivatives by using in situ-formed copper(I)-based complexes as a photoredox catalyst is presented. This method enables the generation of the C(sp3)-centered radicals through site selective cleavage of the C-S bond of aryl sulfonium salts under mild conditions. Moreover, the oxidation reactions of desired products provide a new strategy for the preparation of sulfoxide or sulfone-containing compounds. Importantly, this approach can be easily applied to late-stage modification of pharmaceuticals molecules.

3.
J Org Chem ; 89(1): 281-290, 2024 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-38109762

RESUMEN

A visible-light-driven photoredox dialkylation of styrenes with α-carbonyl alkyl bromides and pyridin-1-ium salts for the synthesis of polysubstituted 1,4-dihydropyridines is reported. This reaction enables the formation of two new C(sp3)-C(sp3) bonds in a single reaction step and provides a strategy that employs pyridin-1-ium salts as the functionalized alkylating reagents via dearomatization to directly trap the resulting alkyl radicals from radical addition of alkenes and then terminate the alkene dialkylation.

4.
J Org Chem ; 89(5): 2885-2894, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38355424

RESUMEN

Because of their various reactivities, propargyl acetates are refined chemical intermediates that are extensively applied in pharmaceutical synthesis. Currently, reactions between propargyl acetates and chlorosilanes may be the most effective method for synthesizing silylallenes. Nevertheless, owing to the adaptability and selectivity of substrates, transition metal catalysis is difficult to achieve. Herein, nickel-catalyzed reductive cross-coupling reactions between propargyl acetates and substituted vinyl chlorosilanes for the synthesis of tetrasubstituted silylallenes are described. Therein, metallic zinc is a crucial reductant that effectively enables two electrophilic reagents to selectively construct C(sp2)-Si bonds. Additionally, a Ni-catalyzed reductive mechanism involving a radical process is proposed on the basis of deuteration-labeled experiments.

5.
EMBO J ; 38(2)2019 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-30523147

RESUMEN

Proper temporal and spatial activation of stem cells relies on highly coordinated cell signaling. The primary cilium is the sensory organelle that is responsible for transmitting extracellular signals into a cell. Primary cilium size, architecture, and assembly-disassembly dynamics are under rigid cell cycle-dependent control. Using mouse incisor tooth epithelia as a model, we show that ciliary dynamics in stem cells require the proper functions of a cholesterol-binding membrane glycoprotein, Prominin-1 (Prom1/CD133), which controls sequential recruitment of ciliary membrane components, histone deacetylase, and transcription factors. Nuclear translocation of Prom1 and these molecules is particularly evident in transit amplifying cells, the immediate derivatives of stem cells. The absence of Prom1 impairs ciliary dynamics and abolishes the growth stimulation effects of sonic hedgehog (SHH) treatment, resulting in the disruption of stem cell quiescence maintenance and activation. We propose that Prom1 is a key regulator ensuring appropriate response of stem cells to extracellular signals, with important implications for development, regeneration, and diseases.


Asunto(s)
Antígeno AC133/metabolismo , Cilios/metabolismo , Incisivo/citología , Antígeno AC133/genética , Animales , Núcleo Celular/metabolismo , Células Cultivadas , Humanos , Incisivo/metabolismo , Ratones , Modelos Biológicos , Mutagénesis Sitio-Dirigida , Transporte de Proteínas , Transducción de Señal , Células Madre/citología , Células Madre/metabolismo
6.
Mol Biol Rep ; 50(6): 5415-5423, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37085741

RESUMEN

BACKGROUND: We systematically summarized the structure and biological function of DOT1L in detail, and further discussed the role of DOT1L in kidney diseases through different mechanisms. METHODS AND RESULTS: We first described the role of DOT1L in various kidney diseases including AKI, CKD, DN and kidney tumor diseases. CONCLUSIONS: A better understanding of DOT1L as a histone methylase based on characteristics of regulating telomere silencing, transcriptional extension, DNA damage repair and cell cycle could lead to the development of new therapeutic targets for various kidney diseases, thereby improving the prognosis of kidney disease patients.


Asunto(s)
Enfermedades Renales , Neoplasias , Humanos , Ciclo Celular , Reparación del ADN , N-Metiltransferasa de Histona-Lisina/genética , N-Metiltransferasa de Histona-Lisina/metabolismo , Histonas , Metiltransferasas/genética
7.
J Chem Phys ; 158(17)2023 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-37125711

RESUMEN

Organic semiconductors (OSCs) are widely used in flexible display, renewable energy, and biosensors, owing to their unique solid-state physical and optoelectronic properties. Among the abundant crystal library of OSCs, asymmetric aryl anthracene derivatives have irreplaceable advantages due to the interplay between their distinct π-conjugated geometry and molecular stacking as well as efficient light emission and charge transport properties that can be simultaneously utilized. However, the poor crystal stacking patterns of most asymmetric molecules limit their utility as excellent OSCs. Thus, it is crucial to clarify the structural features that enable the extremely ordered stacking and favorable electronic structure of asymmetric anthracene derivatives to become high-performance OSCs. This contribution investigates the charge transport properties of a series of asymmetric aryl anthracene derivatives to reveal the modulation factors of the molecular stacking modes and to explore the structural factors, which are beneficial to charge transport. The analysis demonstrated that the vinyl-linker facilitated the injection of hole carriers, and the alkynyl-linker effectively reduces the reorganization energy. Importantly, the linear polarizability and permanent dipole moment of a single molecule play a vital regulation to molecular stacking modes and the transfer integral of the dimer. The "head-to-head stacking" motif shows a compact stacking pattern and the maximum 2D anisotropic mobility more than 10 cm2 V-1 s-1. These findings sharpen our understanding of the charge transport properties in asymmetric organic semiconductors and are essential for developing a diverse range of high-performance OSC materials.

8.
Int J Clin Pract ; 2023: 6396576, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37808625

RESUMEN

Background: Rhabdomyolysis (RM) refers to a clinical syndrome in which muscle cells are damaged by various causes and the clinical manifestations are mainly muscle pain, weakness, and dark urine. Acute kidney injury (AKI) is a serious complication of RM with complex mechanisms and high mortality. Therefore, understanding the pathogenesis and clinical manifestations, early diagnosis and treatment of RM are crucial to improve its prognosis. Method: Analysis of medical records of RM patients admitted to Tianjin Medical University General Hospital from October 2019 to October 2022. Statistical software SPSS 25.0 was used to analyze the data. The risk factors of RM-complicated AKI were analyzed by logistic regression. The receiver operating characteristic (ROC) curve was plotted, the area under the curve (AUC) was calculated, and the optimal cutoff value was determined by the Youden index. P < 0.05 indicates a statistically significant difference between the groups. Result: Among the 71 patients, the median age of the patients was 53.0 (30.0, 71.0) years and was 2.5 times higher in men than in women. Infection was the most common etiology. History of alcohol consumption, CK, and creatinine were independent influencing factors for AKI due to RM. Logistic regression analysis showed that CK combined with creatinine had a better predictive value than the single index. Conclusion: Our study revealed the clinical and laboratory characteristics of RM in the population attending the Tianjin Medical University General Hospital in the last three years, which is a reference for future multicenter, prospective studies.


Asunto(s)
Lesión Renal Aguda , Rabdomiólisis , Femenino , Humanos , Masculino , Lesión Renal Aguda/epidemiología , Lesión Renal Aguda/etiología , Creatinina , Pronóstico , Estudios Prospectivos , Estudios Retrospectivos , Rabdomiólisis/epidemiología , Rabdomiólisis/etiología , Rabdomiólisis/terapia , Curva ROC , Adulto , Persona de Mediana Edad , Anciano
9.
Chem Soc Rev ; 51(16): 7206-7237, 2022 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-35880555

RESUMEN

Alkene-derived radical cations are versatile reactive intermediates and have been widely applied in the construction of complex functionalized molecules and cyclic systems for chemical synthesis. Therefore, the synthetic application of these alkene-derived radical cations represents a powerful and green tool that can be used to achieve the functionalization of alkenes partially because the necessity of stoichiometric external chemical oxidants and/or hazardous reaction conditions is eliminated. This review summarizes the recent advances in the synthetic applications of the electro-/photochemical alkene-derived radical cations, emphasizing the key single-electron oxidation steps of the alkenes, the scope and limitations of the substrates, and the related reaction mechanisms. Using electrocatalysis and/or photocatalysis, single electron transfer (SET) oxidation of the CC bonds in the alkenes occurs, generating the alkene-derived radical cations, which sequentially enables the functionalization of translocated radical cations to occur in two ways: the first involves direct reaction with a nucleophile/radical or two molecules of nucleophiles to realize hydrofunctionalization, difunctionalization and cyclization; and the second involves the transformation of the alkene-derived radical cations into carbon-centered radicals using a base followed by radical coupling or oxidative nucleophilic coupling.


Asunto(s)
Alquenos , Alquenos/química , Cationes/química , Ciclización , Transporte de Electrón , Oxidación-Reducción
10.
Molecules ; 28(4)2023 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-36838760

RESUMEN

Oximes and hydroxylamines are a very important class of skeletons that not only widely exist in natural products and drug molecules, but also a class of synthon, which have been widely used in industrial production. Due to weak N-O σ bonds of oximes and hydroxylamines, they can be easily transformed into other functional groups by N-O bond cleavage. Therefore, the synthesis of N-heterocycle by using oximes and hydroxylamines as nitrogen sources has attracted wide attention. Recent advances for the synthesis of N-heterocycle through transition-metal-catalyzed and radical-mediated cyclization classified by the type of nitrogen sources and rings are summarized. In this paper, the recent advances in the N-O bond cleavage of oximes and hydroxylamines are reviewed. We hope that this review provides a new perspective on this field, and also provides a reference to develop environmentally friendly and sustainable methods.


Asunto(s)
Hidroxilaminas , Oximas , Oximas/química , Hidroxilaminas/química , Catálisis , Ciclización , Nitrógeno
11.
J Am Chem Soc ; 144(1): 339-348, 2022 01 12.
Artículo en Inglés | MEDLINE | ID: mdl-34935377

RESUMEN

A copper-catalyzed remote benzylic C-H functionalization strategy enabling 1,2-difunctionalization of alkenes with 2-methylbenzeneamides and nucleophiles, including alcohols, indoles, pyrroles, and the intrinsic amino groups, is reported, which is characterized by its redox-neutral conditions, exquisite site-selectivity, broad substrate scope, and wide utilizations of late-stage modifying bioactive molecules. This reaction proceeds through nitrogen-centered radical generation, hydrogen atom transfer, benzylic radical addition across the alkenes, single-electron oxidation, and carbocation electrophilic course cascades. While using external nucleophiles manipulates three-component alkene alkylalkoxylation and alkyl-heteroarylation with 2-methylbenzeneamides to access dialkyl ethers, 3-alkylindoles, and 3-alkylpyrroles, omitting the external nucleophiles results in two-component alkylamidation ([5+2] annulation) of alkenes with 2-methylbenzeneamides to benzo-[f][1,2]thiazepine 1,1-dioxides.

12.
Analyst ; 147(15): 3570-3577, 2022 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-35816051

RESUMEN

Lipid droplets (LDs) have emerged as a hot target for cancer therapeutics in recent years owing to findings that have shown them to be key organelles involved in maintaining cellular stability and regulating inter-organelle communication through molecular trafficking. LDs emerge from the endoplasmic reticulum (ER) as a form of cellular homeostasis control. We herein report the study of a library of asymmetric squaraines as superior fluorescence probes to track and image LDs in their native state and environment within cancer cells. The probes are highly selective towards LDs and displayed prominent bright fluorescence with just 1 µM probe concentration. They also possess bimodal LD and ER staining capability via the simple diffusion of small lipophilic molecules. The probes almost instantly stained LDs, while the ER staining rate is dependent on the probe's lipophilicity and the incubation duration. These "on-demand" organelle-selective probes are highly desirable tools for revealing the role of LDs in governing many cellular processes, especially in malignant cells.


Asunto(s)
Gotas Lipídicas , Supervivencia Celular , Ciclobutanos , Retículo Endoplásmico/metabolismo , Gotas Lipídicas/metabolismo , Imagen Molecular , Fenoles , Coloración y Etiquetado
13.
Pediatr Nephrol ; 37(12): 3009-3018, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35338388

RESUMEN

Acute kidney injury (AKI) is a common clinical complication characterized by a sudden deterioration of the kidney's excretory function, which normally occurs secondary to another serious illness. AKI is an important risk factor for chronic kidney disease (CKD) occurrence and progression to kidney failure. It is, therefore, crucial to block the development of AKI as early as possible. To date, existing animal studies have shown that senescence occurs in the early stage of AKI and is extremely critical to prognosis. Cellular senescence is an irreversible process of cell cycle arrest that is accompanied by alterations at the transcriptional, metabolic, and secretory levels along with modified cellular morphology and chromatin organization. Acute cellular senescence tends to play an active role, whereas chronic senescence plays a dominant role in the progression of AKI to CKD. The occurrence of chronic senescence is inseparable from senescence-associated secretory phenotype (SASP) and senescence-related pathways. SASP acts on normal cells to amplify the senescence signal through senescence-related pathways. Senescence can be improved by initiating reprogramming, which plays a crucial role in blocking the progression of AKI to CKD. This review integrates the existing studies on senescence in AKI from several aspects to find meaningful research directions to improve the prognosis of AKI and prevent the progression of CKD.


Asunto(s)
Lesión Renal Aguda , Insuficiencia Renal Crónica , Animales , Humanos , Lesión Renal Aguda/complicaciones , Insuficiencia Renal Crónica/complicaciones , Senescencia Celular , Factores de Riesgo , Cromatina/metabolismo , Progresión de la Enfermedad , Riñón/metabolismo
14.
BMC Emerg Med ; 22(1): 105, 2022 06 11.
Artículo en Inglés | MEDLINE | ID: mdl-35690727

RESUMEN

BACKGROUND: With more emergency visits, there is increasing pressure to provide emergency medical services globally and locally. This study aimed to investigate the epidemiological characteristics and the disease spectrum of patients presenting in the last three years to the Department of Emergency Medicine of Tianjin Medical University General Hospital, a tertiary hospital in Tianjin, China, to improve the services of the emergency medicine department. METHODS: A retrospective study was conducted on all patients in the Department of Emergency Medicine of Tianjin Medical University General Hospital from Jan 1, 2017, 00:00:00 to Dec 31, 2020, 23:59:59, including variables like medical record number, gender, age, date of admission, principal diagnosis. The data were analyzed by SPSS statistical software; statistical charts were prepared by GraphPad Prism9.0 and SPSS 20.0; statistical tables were made by Microsoft Excel. RESULTS: A total of 1,314,916 patients presented to the Department of Emergency Medicine of Tianjin Medical University General Hospital from Jan 1, 2017, 00:00:00 to Dec 31, 2020, 23:59:59. In terms of gender distribution, the male-female ratio was 0.78∶1. As for age distribution, patients aged 60-69 were the most (23.47%), and patients younger than 20 years were the least (2.80%). Concerning monthly data, the number of visits peaked during January and December. The distribution of daily visits showed the feature of three highs and a low. The top three prevalence diseases in the emergency disease spectrum were respiratory, cardiovascular, and digestive diseases. The respiratory system was the most common in patients with infectious diseases (200,912, accounting for 86.97%). Among the patients suffering from infectious diseases, the number of patients with respiratory infections peaked in 2019 (73,530) and was the lowest in 2020 (20,078). CONCLUSIONS: From 2017 to 2019, the demand for emergency services in Tianjin Medical University General Hospital continued to increase, but it was greatly affected by COVID-19 in 2020. This emergency department is mainly for patients with respiratory system, circulatory system and digestive system diseases, and its treatment time is relatively centralized. The prevention of diseases for people of all ages, especially female patients and the elderly, should be strengthened, and emergency medical resources should be allocated reasonably according to the peak months and crowed periods of patients.


Asunto(s)
COVID-19 , Servicio de Urgencia en Hospital , Anciano , Femenino , Hospitales Generales , Humanos , Masculino , Estudios Retrospectivos , Centros de Atención Terciaria
15.
Am J Pathol ; 190(1): 176-189, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31676329

RESUMEN

Nephronophthisis (NPHP), the leading genetic cause of end-stage renal failure in children and young adults, is a group of autosomal recessive diseases characterized by kidney-cyst degeneration and fibrosis for which no therapy is currently available. To date, mutations in >25 genes have been identified as causes of this disease that, in several cases, result in chronic DNA damage in kidney tubular cells. Among such mutations, those in the transcription factor-encoding GLIS2 cause NPHP type 7. Loss of function of mouse Glis2 causes senescence of kidney tubular cells. Senescent cells secrete proinflammatory molecules that induce progressive organ damage through several pathways, among which NF-κB signaling is prevalent. Herein, we show that the NF-κB signaling is active in Glis2 knockout kidney epithelial cells and that genetic inactivation of the toll-like receptor (TLR)/IL-1 receptor or pharmacologic elimination of senescent cells (senolytic therapy) reduces tubule damage, fibrosis, and apoptosis in the Glis2 mouse model of NPHP. Notably, in Glis2, Tlr2 double knockouts, senescence was also reduced and proliferation was increased, suggesting that loss of TLR2 activity improves the regenerative potential of tubular cells in Glis2 knockout kidneys. Our results further suggest that a combination of TLR/IL-1 receptor inhibition and senolytic therapy may delay the progression of kidney disease in NPHP type 7 and other forms of this disease.


Asunto(s)
Senescencia Celular/inmunología , Modelos Animales de Enfermedad , Inmunidad Innata/inmunología , Enfermedades Renales Quísticas/patología , Túbulos Renales/patología , Factores de Transcripción de Tipo Kruppel/fisiología , Proteínas del Tejido Nervioso/fisiología , Animales , Apoptosis , Enfermedades Renales Quísticas/inmunología , Enfermedades Renales Quísticas/metabolismo , Túbulos Renales/inmunología , Túbulos Renales/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Factor 88 de Diferenciación Mieloide/fisiología , Receptor Toll-Like 2/fisiología
16.
Lupus ; 30(7): 1192-1196, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33784848

RESUMEN

Acute pericardial tamponade, which can cause obstructive shock, is a serious life-threatening medical emergency that can be readily reversed by timely identification and appropriate intervention. Acute pericardial tamponade can occur for a number of reasons, including idiopathic, malignancy, uremia, iatrogenic, post-myocardial infarction, infection, collagen vascular, hypothyroidism, and others. Systemic lupus erythematosus (SLE) and hyperthyroidism associated with pericardial tamponade are rarely reported. Here, we report the case of a 20-year-old female patient was final diagnosed of SLE with Graves' hyperthyroidism.


Asunto(s)
Taponamiento Cardíaco/etiología , Taponamiento Cardíaco/cirugía , Hipertiroidismo/complicaciones , Lupus Eritematoso Sistémico/complicaciones , Pericardiocentesis/métodos , Enfermedad Aguda , Anticuerpos Antinucleares/inmunología , Taponamiento Cardíaco/diagnóstico , Dolor en el Pecho/etiología , Tos/etiología , Diagnóstico Diferencial , Disnea/etiología , Ecocardiografía Doppler/métodos , Femenino , Humanos , Lupus Eritematoso Sistémico/diagnóstico , Lupus Eritematoso Sistémico/tratamiento farmacológico , Lupus Eritematoso Sistémico/inmunología , Resultado del Tratamiento , Adulto Joven
17.
Org Biomol Chem ; 19(47): 10314-10318, 2021 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-34783815

RESUMEN

A practical and eco-friendly method for the controllable aerobic oxygenation of sulfides by electrochemical catalysis was developed. The switchable preparation of sulfoxides and sulfones was effectively controlled by reaction time, in which both molecular oxygen and water can be used as the oxygen source under catalyst and external oxidant-free conditions. The electrochemical protocol features a broad substrate scope and excellent site selectivity and is successfully applied to the modification of some sulfide-containing pharmaceuticals and their derivatives.

18.
Angew Chem Int Ed Engl ; 60(4): 1861-1868, 2021 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-33079413

RESUMEN

A cobalt-promoted electrochemical 1,2-diarylation of alkenes with electron-rich aromatic hydrocarbons via direct dual C-H functionalizations is described, which employs a radical relay strategy to produce polyaryl-functionalized alkanes. Simply by using graphite rod cathode instead of platinum plate cathode, chemoselectivity of this radical relay strategy is shifted to the dehydrogenative [2+2+2] cycloaddition via 1,2-diarylation, annulation, and dehydrogenation cascades leading to complex 11,12-dihydroindolo[2,3-a]carbazoles. Mechanistical studies indicate that a key step for the radical relay processes is transformations of the aromatic hydrocarbons to the aryl sp2 -hybridized carbon-centered radicals via deprotonation of the corresponding aryl radical cation intermediates with bases.

19.
Angew Chem Int Ed Engl ; 60(39): 21360-21367, 2021 09 20.
Artículo en Inglés | MEDLINE | ID: mdl-34291545

RESUMEN

We report an unprecedented, efficient nickel-catalysed radical relay for the remote cross-electrophile coupling of ß-bromo-α-benzylamino acid esters with aryl bromides via 1,4-aryl migration/arylation cascades. ß-Bromo-α-benzylamino acid esters are considered as unique molecular scaffolds allowing for aryl migration reactions, which are conceptually novel variants for the radical Truce-Smiles rearrangement. This reaction enables the formation of two new C(sp3 )-C(sp2 ) bonds using a bench-stable Ni/bipyridine/Zn system featuring a broad substrate scope and excellent diastereoselectivity, which provides an effective platform for the remote aryl group migration and arylation of amino acid esters via redox-neutral C(sp3 )-C(sp2 ) bond cleavage. Mechanistically, this cascade reaction is accomplished by combining two powerful catalytic cycles consisting of a cross-electrophile coupling and radical 1,4-aryl migration through the generation of C(sp3 )-centred radical intermediates from the homolysis of C(sp3 )-Br bonds and the switching of the transient alkyl radical into a robust α-aminoalkyl radical.

20.
Cancer Cell Int ; 20: 63, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32140076

RESUMEN

BACKGROUND: Pancreatic ductal adenocarcinoma (PDA) is one of the most serious causes of death in the world due to its high mortality and inefficacy treatments. MEX3A was first identified in nematodes and was associated with tumor formation and may promote cell proliferation and tumor metastasis. So far, nothing is known about the relationship between MEX3A and PDA. METHODS: In this study, the expression level of MEX3A in PDA tissues was measured by immunohistochemistry. The qRT-PCR and western blot were used to identify the constructed MEX3A knockdown cell lines, which was further used to construct mouse xenotransplantation models. Cell proliferation, colony formation, cell apoptosis and migration were detected by MTT, colony formation, flow cytometry and Transwell. RESULTS: This study showed that MEX3A expression is significantly upregulated in PDA and associated with tumor grade. Loss-of-function studies showed that downregulation of MEX3A could inhibit cell growth in vitro and in vivo. Moreover, it was demonstrated that knockdown of MEX3A in PDA cells promotes apoptosis by regulating apoptosis-related factors, and inhibits migration through influencing EMT. At the same time, the regulation of PDA progression by MEX3A involves changes in downstream signaling pathways including Akt, p-Akt, PIK3CA, CDK6 and MAPK9. CONCLUSIONS: We proposed that MEX3A is associated with the prognosis and progression of PDA,which can be used as a potential therapeutic target.

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