Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 83
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Inorg Chem ; 2020 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-32167757

RESUMO

Two novel thorium-based metal-organic frameworks (MOFs), namely Th-SINAP-7 and Th-SINAP-8, have been synthesized via the solvothermal reactions of thorium nitrate and 1,4- or 2,6-naphthalenedicarboxylic acid in the presence of acid modulators. Bearing the rigid aromatic architectures, Th-SINAP-7 and Th-SINAP-8 exhibit exceptional chemical (from pH 1 to 12) and thermal stabilities (up to 520 °C), as well as ionizing radioresistance (2 × 105 Gy ß and γ irradiations). The highly porous nature and conjugated π-electrons of naphthalene on the organic linkers endow high affinity of both MOFs toward I2 molecules owning to the charge transfer between π-electrons of the host networks and the guest iodine molecules, as evidenced by combined techniques including of FTIR, PXRD, SEM-EDS, UV-vis spectroscopy, XPS, and Raman spectroscopy. Particularly, Th-SINAP-8 can efficiently remove >99% I2 from cyclohexane solution and exhibit guest uptake of iodine vapor with an adsorption capacity of 473 mg/g.

2.
Inorg Chem ; 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-32017542

RESUMO

The directing effect of coordinating ligands in the formation of uranium molecular complexes has been well established, but the role of counterions in metal-ligand interactions remains ambiguous and requires further investigation. In this work, we describe the targeted isolation, through the choice of alkali-metal ions, of a family of tetravalent uranium sulfates, showing the influence of the overall topology and, unexpectedly, the UIV nuclearity upon the inclusion of such countercations. Analyses of the structures of uranium(IV) oxo/hydroxosulfate oligomeric species isolated from consistent synthetic conditions reveal that the incorporation of Na+ and Rb+ promotes the crystallization of 0D discrete clusters with a hexanuclear [U6O4(OH)4(H2O)4]12+ core, whereas the larger Cs+ ion allows for the isolation of a 2D-layered oligomer with a less condensed trinuclear [U3(O)]10+ center. This finding expands the prevalent view that counterions play an innocent role in molecular complex synthesis, affecting only the overall packing but not the local oligomerization. Interestingly, trends in nuclearity appear to correlate with the hydration enthalpies of alkali-metal cations, such that the alkali-metal cations with larger hydration enthalpies correspond to more hydrated complexes and cluster cores. These findings afford new insights into the mechanism of nucleation of UIV, and they also open a new path for the rational design and synthesis of targeted molecular complexes.

3.
Adv Sci (Weinh) ; 6(17): 1900381, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31508271

RESUMO

Various types of polyoxometalates (POMs) have been synthesized since the 19th century, but their assortment has been mostly limited to Groups 5 and 6 metals. Herein, a new family of POMs composed of a carbon group element as the addenda atoms with two distinct phases, LnPbOClO4-1 (Ln = Sm to Ho, Y) and LnPbOClO4-2 (Ln = Er and Tm) is reported. Both structures are built from [Ln6O8] rare-earth metal hexamers being incorporated in [Pb18O32]/[Pb12O24] polyplumbites, and unbound perchlorates as charge-balancing anions. Impressively, YPbOClO4-1 and ErPbOClO4-2 exhibit exceptional uptake capacities (434.7 and 427.7 mg g-1) toward ReO4 -, a chemical surrogate for the key radioactive fission product in the nuclear fuel cycle 99TcO4 -, which are the highest values among all inorganic anion-exchange materials reported until now. The sorption mechanism is clearly elucidated and visualized by single-crystal-to-single-crystal structural transformation from ErPbOClO4-2 to a perrhenate-containing complex ErPbOReO4 , revealing a unique ReO4 - uptake selectivity driven by specific interaction within Pb···O-ReO3 - bonds.

4.
J Synchrotron Radiat ; 26(Pt 5): 1733-1741, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31490165

RESUMO

The microscopic structures of ThF4-LiF and ThF4-LiF-BeF2 molten salts have been systematically investigated by in situ high-temperature X-ray absorption fine-structure (XAFS) spectroscopy combined with molecular-dynamics (MD) simulations. The results reveal that the local structure of thorium ions was much more disordered in the molten state of the ThF4-LiF-BeF2 salt than that in ThF4-LiF, implying that the Th and F ions were exchanged more frequently in the presence of Be ions. The structures of medium-range-ordered coordination shells (such as Th-F2nd and Th-Th) have been emphasized by experimental and theoretical XAFS analysis, and they play a significant role in transport properties. Using MD simulations, the bonding properties in the molten ThF4-LiF and ThF4-LiF-BeF2 mixtures were evaluated, confirming the above conclusion. This research is, to the best of our knowledge, the first systematic study on the ThF4-LiF-BeF2 molten salt via quantitative in situ XAFS analysis and MD simulations.

5.
Nat Commun ; 10(1): 3755, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31434892

RESUMO

Facile and reliable screening of cost-effective, high-performance and scalable electrocatalysts is key for energy conversion technologies such as water splitting. ABO3-δ perovskites, with rich constitutions and structures, have never been designed via activity descriptors for critical hydrogen evolution reaction (HER). Here, we apply coordination rationales to introduce A-site ionic electronegativity (AIE) as an efficient unifying descriptor to predict the HER activities of 13 cobalt-based perovskites. Compared with A-site structural or thermodynamic parameter, AIE endows the HER activity with the best volcano trend. (Gd0.5La0.5)BaCo2O5.5+δ predicted from an AIE value of ~2.33 exceeds the state-of-the-art Pt/C catalyst in electrode activity and stability. X-ray absorption and computational studies reveal that the peak HER activities at a moderate AIE value of ~2.33 can be associated with the optimal electronic states of active B-sites via inductive effect in perovskite structure (~200 nm depth), including Co valence, Co-O bond covalency, band gap and O 2p-band position.

6.
Dalton Trans ; 48(34): 12808-12811, 2019 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-31348473

RESUMO

A unique selective crystallization strategy based on an iodate-sulfate mixed-anion system has been developed for lanthanide separation. Periodic divergences in crystal formation energy enable simple Nd/Dy, La/Lu, Gd/Tb, La/Dy, and Nd/Lu separations through crystallization of the early lanthanides, giving rise to separation factors up to 123(5), 100(2), 2.4(2), 137(9), and 85(6), respectively.

7.
Nat Commun ; 10(1): 1428, 2019 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-30926804

RESUMO

Understanding the catalytic mechanism of bimetallic nanocatalysts remains challenging. Here, we adopt an adsorbate mediated thermal reduction approach to yield monodispersed AuPd catalysts with continuous change of the Pd-Au coordination numbers embedded in a mesoporous carbonaceous matrix. The structure of nanoalloys is well-defined, allowing for a direct determination of the structure-property relationship. The results show that the Pd single atom and dimer are the active sites for the base-free oxidation of primary alcohols. Remarkably, the d-orbital charge on the surface of Pd serves as a descriptor to the adsorbate states and hence the catalytic performance. The maximum d-charge gain occurred in a composition with 33-50 at% Pd corresponds to up to 9 times enhancement in the reaction rate compared to the neat Pd. The findings not only open an avenue towards the rational design of catalysts but also enable the identification of key steps involved in the catalytic reactions.

8.
Dalton Trans ; 48(15): 4823-4829, 2019 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-30724286

RESUMO

Expanding the family of f-element bearing molybdate iodates via hydrothermal reactions has yielded ten new rare-earth molybdate iodates with two distinct phases, Ln(MoO2)(IO3)4(OH) (LnMoIO-1, Ln = Ce and Pr) and Ln(Mo2O7)(IO3)(H2O)2 (LnMoIO-2, Ln = Gd-Yb, and Y), as well as the first thorium molybdate iodate, ThF(MO4)(IO3) (ThFMoIO). All three structures exhibit three dimensional frameworks and are exclusively built from lanthanide/actinide polyhedra bridged by molybdates and iodates. Furthermore, the coordination versatility of molybdates (octahedral, square pyramidal, and tetrahedral geometries) results in a diversity of structures. The effect of the lanthanide contraction on the compositions and structures is clearly observed, showing the increase in hydration from the early to late lanthanide analogues and the decrease in unit cell dimensions and the average Ln-O bonding distances across the same structure type. Single crystal X-ray diffraction studies reveal that LnMoIO-1 (Ln = Ce and Pr) crystalize in a noncentrosymmetric space group P21 and the second-harmonic generation (SHG) measurement shows a response of 5 × KDP for PrMoIO-1. In addition, CeMoIO-1 crystallizes as orange coloured tablets which are semiconducting in nature with a band gap of 2.41 eV.

9.
PLoS One ; 13(12): e0208166, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30586437

RESUMO

The financial risk not only affects the development of the company itself, but also affects the economic development of the whole society; therefore, the financial risk assessment of company is an important part. At present, numerous methods of financial risk assessment have been researched by scholars. However, most of the extant methods neither integrated fuzzy sets with quantitative analysis, nor took into account the historical data of the past few years. To settle these defects, this paper proposes a novel financial risk assessment model for companies based on heterogeneous multiple-criteria decision-making (MCDM) and historical data. Subjective and objective indexes are comprehensively taken into consideration in the financial risk assessment index system of the model, which combines fuzzy theory with quantitative data analysis. Moreover, the assessment information obtained from historical financial information of company, credit rating agency and decision makers, including crisp numbers, triangular fuzzy numbers and neutrosophic numbers. Furthermore, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method is used to determine the ranking order of companies according to their financial risk. Finally, an empirical study of financial risk assessment for companies is conducted, and the results of comparative analysis and sensitivity analysis suggest that the proposed model can effectively and reliably obtain the company with the lowest financial risk.


Assuntos
Comércio/organização & administração , Tomada de Decisões , Técnicas de Apoio para a Decisão , Administração Financeira/métodos , Modelos Econômicos , Comércio/economia , Análise de Dados , Lógica Fuzzy , Medição de Risco/métodos
10.
Dalton Trans ; 47(42): 14908-14916, 2018 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-30183785

RESUMO

Uranium is unique owing not only to its intriguing physiochemical properties, but also to the diverse coordination chemistry that uranyl adopts and bonding that enables rich and unpredictable topologies of uranium-bearing materials. Six anionic uranium oxyfluorides with various dimensionalities, including a 3D framework (MeUF), four 2D lamellar structures (EtUF-1, PrUF, BuUF-1, and BuUF-2), and a 1D chained topology (EtUF-2), have been rationally constructed by employing tetra-alkyl ammonium ions as structure-directing agents. By combining the tunable interlayer distance of the lamellar structures with the photooxygenation properties of uranyl ions, a bifunctional platform for highly selective ion-exchange and photocatalytic degradation over organic dyes has been developed. Specifically, BuUF-2 can efficiently capture 94.5% methylene blue (MB+) within 24 h from solution with remarkable selectivity related to both the size and the charge of organic dyes. Such size- and charge-dependent selectivity toward organic dyes has been documented for MOFs, but is rare for 2D lamellar materials. Furthermore, the removal of MB+ can be largely accelerated under UV radiation (e.g. 84.7% for BuUF-2 within 1 h) due to the photocatalytic activities of EtUF-1, EtUF-2, PrUF, and BuUF-2.

11.
Inorg Chem ; 57(18): 11404-11413, 2018 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-30146883

RESUMO

Knowledge of the local Th structure is a prerequisite for a better understanding of the physicochemical properties of the thorium-based mixed oxides (Th-MOX) involved in the Th-based nuclear fuel cycle. The crystalline electric field (CEF) splitting of the 6d shell in Th1- xU xO2 ( x = 0.25, 0.5, 0.75) solid solution was probed by the Th L3 edge high-energy-resolution fluorescence-detected (HERFD) X-ray absorption near-edge spectroscopy (XANES) collected at the Lß5 emission line, which cannot be obtained by conventional X-ray absorption methods. The detected CEF split between the 6d eg and t2g orbitals in ThO2 consisting of ordered Th-O8 cubes with cubic symmetry is ∼3.5 eV for the Th4+ ion. Because the split peaks of the white line corresponding to the crystal-field splitting of the unoccupied 6d states were resolved in the HERFD-XANES spectra, the analysis of these split peaks combined with first-principles calculations revealed that an increase of the U content involves the distortion of the Th-O8 cubes in the Th1- xU xO2 mixed oxides. The lower symmetry of the Th-O8 cube induced by the incorporated U tends to reduce the local crystal-field around Th4+ as well as the hybridization of Th 6t2g-O 2p which is mainly responsible for the covalent property of the Th-O bond. The phenomenon is noticeable in Th0.25U0.75O2, whose CEF splitting is decreased by approximately 10%, and covalent mixing between Th 6d t2g and O 2p orbitals is substantially reduced compared to that of pure ThO2.

12.
Inorg Chem ; 57(12): 6778-6782, 2018 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-29869873

RESUMO

Searching for cationic extended materials with a capacity for anion exchange resulted in a unique thorium molybdate chloride (TMC) with the formula of [Th(MoO4)(H2O)4Cl]Cl·H2O. The structure of TMC is composed of zigzagging cationic layers [Th(MoO4)(H2O)4Cl]+ with Cl- as interlamellar charge-balancing anions. Instead of performing ion exchange, alkali thorium fluorides were formed after soaking TMC in AF (A = Na, K, and Cs) solutions. The mechanism of AF immobilization is elucidated by the combination of SEM-EDS, PXRD, FTIR, and EXAFS spectroscopy. It was observed that four water molecules coordinating with the Th4+ center in TMC are vulnerable to competition with F-, due to the formation of more favorable Th-F bonds compared to Th-OH2. This leads to a single crystal-to-polycrystalline transformation via a pathway of recrystallization to form alkali thorium fluorides.

13.
Oncol Lett ; 16(1): 317-325, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29928417

RESUMO

Breast cancer remains the leading cause of mortality worldwide. Human papilloma virus 16 (HPV16) may serve a function in the pathogenesis and development of breast cancer. However, the detection rate of HPV16 in breast carcinoma may vary by region. In the present study, the expression of HPV16 E7 in paraffin-embedded tissues from patients with breast cancer from North China was detected. Additionally, the molecular mechanisms underlying the function of HPV16 E7 in the proliferation of breast cancer cells were examined. The results demonstrated that the DNA of HPV16 E7 was detected in 30.5% of the samples, and that HPV16 E7 promoted the proliferation of breast cancer cells in vitro and in vivo. Additionally, HPV16 E7-mediated proliferation of breast cancer cells was suppressed in response to treatment with cyclooxygenase-2 (COX-2)-specific small interfering RNA and celecoxib. The results of the present study revealed that HPV16 E7 may promote the proliferation of breast cancer cells by upregulating COX-2, suggesting that COX-2 may be a potential therapeutic target for HPV16 E7-mediated progression of breast cancer.

14.
Inorg Chem ; 57(11): 6753-6761, 2018 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-29792317

RESUMO

By utilizing zinc amalgam as an in situ reductant and pH regulator, mild hydrothermal reaction between UO2(CH3COO)2·2H2O, H2SO4, and Cs2CO3 or between UO2(CH3COO)2·2H2O, C2H4(SO3H)2, and K2CO3 yielded a novel cesium UIV sulfate trimer Cs4[U3O(SO4)7]·2.2H2O (1) and a new potassium UIV disulfonic hexamer K[U6O4(OH)5(H2O)5][C2H4(SO3)2]6·6H2O (2), respectively. Compound 1 features a lamellar structure with a honeycomb lattice, and it represents an unprecedented trimeric UIV cluster composed of purely inorganic moieties. Complex 2 is built from hexanuclear U4+ cores and K+ ions interconnected by µ5-[C2H4(SO3)2]2- groups, leading to the construction of an extended framework rather than commonly observed discrete, neutral molecular sulfonate clusters. The various binding modes of the sulfate and disulfonate groups, especially the multidentate ones, enable additional bridging between metal ions, which promotes oligomerization and isolation of polynuclear species. Furthermore, compound 1 exhibits both ion-exchange properties and the Alexandrite effect, and it is the second example of a uranium complex without chromic functional ligands displaying the latter feature.

15.
ChemSusChem ; 11(11): 1880-1886, 2018 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-29667363

RESUMO

The energy and power density of conventional batteries are far lower than their theoretical expectations, primarily because of slow reaction kinetics that are often observed under ambient conditions. Here we describe a low-cost and high-temperature rechargeable iron-oxygen battery containing a bi-phase electrolyte of molten carbonate and solid oxide. This new design merges the merits of a solid-oxide fuel cell and molten metal-air battery, offering significantly improved battery reaction kinetics and power capability without compromising the energy capacity. The as-fabricated battery prototype can be charged at high current density, and exhibits excellent stability and security in the highly charged state. It typically exhibits specific energy, specific power, energy density, and power density of 129.1 Wh kg-1 , 2.8 kW kg-1 , 388.1 Wh L-1 , and 21.0 kW L-1 , respectively, based on the mass and volume of the molten salt.

16.
Oncol Lett ; 15(4): 4105-4112, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29556285

RESUMO

The clinical significance and essential role of long non-coding RNA colorectal neoplasia differentially expressed (lncRNA CRNDE) have been well illuminated in various cancers. However, the function of CRNDE in intrahepatic cholangiocarcinoma (IHCC) has not been reported at present. The aim of the present study was to investigate the role of CRNDE in IHCC. Firstly, the relative expression of CRNDE was observed to be upregulated in IHCC cell lines and tissues. And high CRNDE expression was statistically associated with IHCC differentiation grade, lymph node metastasis, tumor-nodes-metastasis (TNM) stage and size. Survival analysis identified that high CRNDE expression is a predictor of worse overall survival (OS) and progression-free survival (PFS) in patients with IHCC. Moreover, high CRNDE expression was identified as an independent risk factor of IHCC poor OS and PFS. Further studies of in vitro assays suggested that CRNDE silencing could suppress the proliferation of HuCCT1 cells following CCK-8 and colony formation assays, while CRNDE ectopic expression in HCCC9810 cells promoted proliferation. Moreover, the migration and invasion of HuCCT1 cells were greatly repressed with CRNDE deficiency following Transwell and Matrigel assays. Accordingly, the motility of HCCC9810 cells was notably accelerated with CRNDE overexpression. Mechanistically, CRNDE was revealed to facilitate the epithelial-mesenchymal transition (EMT) of IHCC cells. In conclusion, these observations indicated that CRNDE could promote the clinical progression and metastasis of IHCC by facilitating EMT. CRNDE may be a novel prognostic marker and therapeutic target in IHCC.

17.
J Synchrotron Radiat ; 25(Pt 2): 514-522, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29488931

RESUMO

The present study sheds some light on the long-standing debate concerning the coordination properties between uranyl ions and the amidoxime ligand, which is a key ingredient for achieving efficient extraction of uranium. Using X-ray absorption fine structure combined with theoretical simulation methods, the binding mode and bonding nature of a uranyl-amidoxime complex in aqueous solution were determined for the first time. The results show that in a highly concentrated amidoxime solution the preferred binding mode between UO22+ and the amidoxime ligand is η2 coordination with tris-amidoximate species. In such a uranyl-amidoximate complex with η2 binding motif, strong covalent interaction and orbital hybridization between U 5f/6d and (N, O) 2p should be responsible for the excellent binding ability of the amidoximate ligand to uranyl. The study was performed directly in aqueous solution to avoid the possible binding mode differences caused by crystallization of a single-crystal sample. This work also is an example of the simultaneous study of local structure and electronic structure in solution systems using combined diagnostic tools.

18.
Inorg Chem ; 57(3): 1676-1683, 2018 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-29345469

RESUMO

The exploration of phase formation in the f-element-bearing iodate selenate system has resulted in 14 novel rare-earth-containing iodate selenates, Ln(IO3)(SeO4) (Ln = La, Ce, Pr, Nd; LnISeO-1), Ln(IO3)(SeO4)(H2O) (Ln = Sm, Eu; LnISeO-2), and Ln(IO3)(SeO4)(H2O)2·H2O (Ln = Gd, Dy, Ho, Er, Tm, Yb, Lu, Y; LnISeO-3), as well as two new thorium iodate selenates, Th(OH)(IO3)(SeO4)(H2O) (ThISeO-1) and Th(IO3)2(SeO4) (ThISeO-2). LnISeO-3 and ThISeO-2 crystallize in the chiral space group P212121, while LnISeO-1, LnISeO-2, and ThISeO-1 crystallize in the centrosymmetric space group P21/c. The numbers of both coordinating and hydrating water molecules crystallized in LnISeO-1, LnISeO-2, and LnISeO-3 increase along these three series, in line with the increasingly negative values of hydration enthalpies of heavier trivalent lanthanide ions. Such a systematic change in compositions, especially the first coordination sphere of Ln, further induces structural rearrangements, including coordination number and dimensional reductions. More specifically, the structures of LnISeO-1, LnISeO-2, and LnISeO-3 have undergone transitions from 2D Ln-oxo layers with 10-coordinate Ln centers to 1D Ln-oxo chains with 9-coordinate Ln centers and then to 0D Ln-oxo monomers with 8-coordinate Ln centers, respectively. The formation and characterization of this large family of Ln/Th iodate selenates suggest that such a mixed-anion system not only exhibits richer structural chemistry but also can be capable of generating intriguing properties, such as the second-harmonic generation (SHG) effect.

19.
Adv Mater ; 30(6)2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29315852

RESUMO

Increasing visible light absorption of classic wide-bandgap photocatalysts like TiO2 has long been pursued in order to promote solar energy conversion. Modulating the composition and/or stoichiometry of these photocatalysts is essential to narrow their bandgap for a strong visible-light absorption band. However, the bands obtained so far normally suffer from a low absorbance and/or narrow range. Herein, in contrast to the common tail-like absorption band in hydrogen-free oxygen-deficient TiO2 , an unusual strong absorption band spanning the full spectrum of visible light is achieved in anatase TiO2 by intentionally introducing atomic hydrogen-mediated oxygen vacancies. Combining experimental characterizations with theoretical calculations reveals the excitation of a new subvalence band associated with atomic hydrogen filled oxygen vacancies as the origin of such band, which subsequently leads to active photo-electrochemical water oxidation under visible light. These findings could provide a powerful way of tailoring wide-bandgap semiconductors to fully capture solar light.

20.
World J Gastroenterol ; 23(13): 2318-2329, 2017 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-28428711

RESUMO

AIM: To explore the functional role of cullin 4A (CUL4A), a core subunit of E3 ubiquitin ligase, in perihilar cholangiocarcinoma (PHCC). METHODS: The expression of CUL4A in PHCC cell lines was evaluated by Western blot and quantitative reverse transcription-polymerase chain reaction. Immunohistochemistry (IHC) was adopted to investigate the relationship between CUL4A expression and clinicopathological characteristics of PHCC. Univariate analysis and multivariate regression analysis were performed to analyze the risk factors related to overall survival (OS) and progression-free survival (PFS) of PHCC patients. Wound healing, Transwell and Matrigel assays were utilized to explore the function of CUL4A in PHCC metastasis. Furthermore, expression of epithelial to mesenchymal transition (EMT) markers was verified in cells with CUL4A knockdown or overexpression. The relationship between CUL4A expression and E-cadherin expression was also analyzed by IHC assay. Finally, the role of ZEB1 in regulating CUL4A mediated PHCC was detected by IHC, Western blot, Transwell and Matrigel assays. RESULTS: CUL4A overexpression was detected in PHCC cell lines and clinical specimens. Clinicopathological analysis revealed a close correlation between CUL4A overexpression and tumour differentiation, T, N and TNM stages in PHCC. Kaplan-Meier analysis revealed that high CUL4A expression was correlated with poor OS and PFS of PHCC patients. Univariate analysis identified the following four parameters as risk factors related to OS rate of PHCC: T, N, TNM stages and high CUL4A expression; as well as three related to PFS: N stage, TNM stage and high CUL4A expression. Further multivariate logistic regression analysis identified high CUL4A expression as the only independent prognostic factor for PHCC. Moreover, CUL4A silencing in PHCC cell lines dramatically inhibited metastasis and the EMT. Conversely, CUL4A overexpression promoted these processes. Mechanistically, ZEB1 was discovered to regulate the function of CUL4A in promoting the EMT and metastasis. CONCLUSION: CUL4A is an independent prognostic factor for PHCC, and it can promote the EMT by regulating ZEB1 expression. CUL4A may be a potential therapeutic target for PHCC.


Assuntos
Neoplasias dos Ductos Biliares/metabolismo , Proteínas Culina/metabolismo , Transição Epitelial-Mesenquimal , Tumor de Klatskin/metabolismo , Neoplasias dos Ductos Biliares/mortalidade , Neoplasias dos Ductos Biliares/patologia , Ductos Biliares/patologia , Linhagem Celular , Movimento Celular , Regulação Neoplásica da Expressão Gênica , Humanos , Tumor de Klatskin/mortalidade , Tumor de Klatskin/patologia , Metástase Neoplásica , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA