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1.
Anim Biosci ; 36(9): 1327-1335, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37170517

ABSTRACT

OBJECTIVE: When evaluating individuals with the same parent and no phenotype by pedigree best linear unbiased prediction (BLUP), it is difficult to explain carcass grade difference and select individuals because they have the same value in pedigree BLUP (PBLUP). However, single step GBLUP (ssGBLUP), which can estimate the breeding value suitable for the individual by adding genotype, is more accurate than the existing method. METHODS: The breeding value and accuracy were estimated with pedigree BLUP and ssGBLUP using pedigree and genotype of 408 Hanwoo cattle from 16 families with the same parent among siblings produced by fertilized egg transplantation. A total of 14,225 Hanwoo cattle with pedigree, genotype and phenotype were used as the reference population. PBLUP obtained estimated breeding value (EBV) using the pedigree of the test and reference populations, and ssGBLUP obtained genomic EBV (GEBV) after constructing and H-matrix by integrating the pedigree and genotype of the test and reference populations. RESULTS: For all traits, the accuracy of GEBV using ssGBLUP is 0.18 to 0.20 higher than the accuracy of EBV obtained with PBLUP. Comparison of EBV and GEBV of individuals without phenotype, since the value of EBV is estimated based on expected values of alleles passed down from common ancestors. It does not take Mendelian sampling into consideration, so the EBV of all individuals within the same family is estimated to be the same value. However, GEBV makes estimating true kinship coefficient based on different genotypes of individuals possible, so GEBV that corresponds to each individual is estimated rather than a uniform GEBV for each individual. CONCLUSION: Since Hanwoo cows bred through embryo transfer have a high possibility of having the same parent, if ssGBLUP after adding genotype is used, estimating true kinship coefficient corresponding to each individual becomes possible, allowing for more accurate estimation of breeding value.

2.
Bioelectrochemistry ; 151: 108393, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36739701

ABSTRACT

As an emerging versatile technology for separating uranium from uranium-containing wastewater (UCW), microbial fuel cell (MFC) offers a novel approach to UCW treatment. Its cathode is essential for the treatment of UCW. To thoroughly investigate the efficacy of MFC in treating UCW, investigations were conducted using MFCs with five materials (containing iron sheet (IP), stainless steel mesh (SSM), carbon cloth (CC), carbon brush (CB), and nickel foam (NF)) as cathodes. The results revealed that each MFC system performed differently in terms of carbon source degradation, uranium removal, and electricity production. In terms of carbon source degradation, CB-MFC showed the best performance. The best uranium removal method was NF-MFC, and the best electricity production method was carbon-based cathode MFC. Five MFC systems demonstrated stable performance and consistent difference over five cycles, with CC-MFC outperforming the others. Furthermore, SEM and XPS characterization of the cathode materials before and after the experiment revealed that a significant amount of U(IV) was generated during the uranium removal process, indicating that uranium ions were primarily removed by electrochemical reduction precipitation. This study confirmed that abiotic cathode MFC had a high UCW removal potential and served as a good guideline for obtaining the best cathode for MFC.


Subject(s)
Bioelectric Energy Sources , Uranium , Wastewater , Electricity , Carbon , Electrodes , Nickel
3.
Dalton Trans ; 51(33): 12532-12539, 2022 Aug 23.
Article in English | MEDLINE | ID: mdl-35912983

ABSTRACT

LiTMPO4 materials, such as LiNiPO4, can maintain structural stability and Li+ transport activity up to 4.8 V, showing great potential to stabilize layered nickel-rich cathodes at high voltage. But achieving a uniform LiTMPO4 coating layer remains a great challenge. Herein, an ultrathin and uniform LiTMPO4 layer (mainly LiNiPO4) is successfully coated on the surface of LiNi0.8Co0.15Mn0.05O2 (NMC@LTMP) via utilizing the surface chelation of phytic acid with NMC precursors and a subsequent high-temperature in situ reaction. The reconstructed surface and interface could act as stable paths for Li+ transport and efficient barriers against electrolyte corrosion. Thus, harmful side reactions like solid electrolyte interphase overgrowth, irreversible phase transformation, and metal dissolution are inhibited simultaneously. Impressively, the optimized NMC@LTMP2 cathode exhibits remarkably improved capacity, as high as 215 mA h g-1 at 2.8-4.5 V, with capacity retention of 87.21% after 200 cycles and outstanding rate capability of 140 mA h g-1 at 10C, significantly better than a pristine cathode. Furthermore, a pouch cell assembled with an NMC@LTMP2 cathode and graphite anode also exhibits robust capacity retention of 82.42% after 100 cycles. These results provide useful insights towards enabling the application of NMC cathodes via developing facile modification methods.

4.
Chemistry ; 28(23): e202200124, 2022 Apr 22.
Article in English | MEDLINE | ID: mdl-35170808

ABSTRACT

Polyvinyl chloride (PVC) is widely used in daily life, but its waste has become a serious environmental problem. A solid base assisted low-temperature solvothermal dehalogenation was developed in this work to sustainably and efficiently transform PVC into high-value dimethylamine hydrochloride (DMACl) chemical and N,O co-doped carbon monolith with hierarchically porous structure. The synergistic promotion of solid-base catalyst and solvent decomposition with the removal of HCl can shift forward the chemical equilibrium to promote the dechlorination of PVC and increase the carbon yield. Meanwhile, the solid-base catalyst can also act as a pore-forming additive to fabricate the carbon monolith with hierarchical pores. Induced by the high specific surface area, hierarchical pores and N,O co-doped structure, the generated carbon monolith exhibits superior electrocatalytic performance towards H2 evolution. These discoveries shed light on the design of synergistically coupled solvent and solid catalyst to promote the heterogeneous conversion of waste chlorinated plastics into high-value chemicals for a sustainable future.

5.
J Anim Breed Genet ; 139(3): 281-291, 2022 May.
Article in English | MEDLINE | ID: mdl-34902178

ABSTRACT

The genetic improvement of Hanwoo is dependent on the estimated breeding value (EBV) of pedigree-based Korean proven bull's number, and the genetic evaluation for cows is difficult due to insufficient pedigree and test records. Genomic selection involves utilizing the individual's genotype to estimate the breeding value (BV) and is determined to be an appropriate evaluation method for cows who lack test information. This study used pedigree and genotype to estimate and analyse BV and accuracy of Hanwoo cows in the Gyeongnam area using pedigree best linear unbiased prediction (PBLUP) and genomic best linear unbiased prediction (GBLUP). The test group acquired pedigree and genotype of 919 Hanwoo cows in the Gyeongnam area. The traits used for analysis were carcass weight (CWT), eye muscle areas (EMA), backfat thickness (BFT) and marbling score (MS). PBLUP used Reference group 1 containing the pedigree and phenotype of 919 Hanwoo cows and 545,483 heads to construct the numeric relationship matrix and estimated the EBV and accuracy. GBLUP used Reference group 2 containing the genotype and phenotype of 919 Hanwoo cows and 17,226 heads to construct the genomic relationship matrix and estimated the genomic EBV (GEBV) and accuracy. In the order of CWT, EMA, BFT and MS, the accuracy of PBLUP was 0.488, 0.480, 0.482 and 0.486 while the accuracy of GBLUP was higher with 0.779, 0.758, 0.766 and 0.791. And for 104 cows without relationship coefficient on pedigree to the reference group, the accuracy as PBLUP was estimated to be 0, but for GBLUP, it was possible to estimate the accuracy for all individuals. If GBLUP is applied to cows raised in general farms, the genetic evaluation can be performed even on animals without pedigree and high-accuracy estimation, enabling selection of excellent cows. Accordingly, by securing the genetic diversity of cows, it is expected to increase the profitability of farms by decreasing the inbreeding rate and increasing efficiency of elite calf production.


Subject(s)
Genome , Genomics , Animals , Cattle/genetics , Female , Genomics/methods , Genotype , Male , Models, Genetic , Pedigree , Phenotype , Republic of Korea
7.
Chem Commun (Camb) ; 57(46): 5670-5673, 2021 Jun 08.
Article in English | MEDLINE | ID: mdl-33977994

ABSTRACT

Optimizing the active sites to balance the conversion and selectivity of the target reaction has long been a challenging quest in developing noble metal-based catalysts. By dispersing Pd and Ru in an amorphous zirconium hydrogen phosphate matrix cross-linked by ionic inorganic oligomers, highly diluted noble metal (<0.2 mol%) can be utilized as dual single-atom sites in oxides for the semi-hydrogenation of phenylacetylene with optimized conversion and selectivity (both >90%) to styrene. In situ DRIFT-IR results suggested the fast generation of surface hydroxyl groups during the catalytic reaction, indicating the high efficiency of the single-atom sites to dissociate bound H2. This work provides an easily scaled-up method for the production of cost-effective single-atom catalysts extendable to various oxide matrices.

8.
Nanoscale ; 13(3): 1581-1595, 2021 Jan 28.
Article in English | MEDLINE | ID: mdl-33444426

ABSTRACT

Overall electrocatalytic water splitting can efficiently and sustainably produce clean hydrogen energy to alleviate the global energy crisis and environmental pollution. Two-dimensional (2D) materials with a unique band structure and surface conformation have emerged as promising electrocatalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). However, the intrinsic activities of primitive 2D materials in the catalytic process are still inferior to those of noble metal-based electrocatalysts. Surface defect engineering can modulate the electronic structure of 2D materials and induce new physicochemical properties, promoting their electrocatalytic performance. Herein, this minireview focuses on some recent developments in surface defect engineering, including the contribution of active sites, the derivation of the heterogeneous interface, and the anchoring of active substances, which provides an effective way to further optimize 2D electrocatalysts for water splitting. Furthermore, the typical morphological characteristics, catalytic activity, stability and catalytic mechanism of these 2D electrocatalysts are introduced. We believe that this minireview will help design more efficient and economical electrocatalysts for overall water splitting.

9.
J Anim Sci Technol ; 62(4): 429-437, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32803175

ABSTRACT

This study was conducted to construct basic data for the selection of elite cows by analyzing the estimated breeding value (EBV) and accuracy using the pedigree of Hanwoo cows in Gyeongnam. The phenotype trait used in the analysis are the carcass weight (CWT), eye muscle area (EMA), backfat thickness (BFT) and marbling score (MS). The pedigree of the test group and reference group was collected to build a pedigree structure and a numeric relationship matrix (NRM). The EBV, genetic parameters and accuracy were estimated by applying NRM to the best linear unbiased prediction (BLUP) multiple-trait animal model of the BLUPF90 program. Looking at the pedigree structure of the test group, there were a total of 2,371 cows born between 2003 to 2009, of these 603 cows had basic registration (25%), 562 cows had pedigree registration (24%) and 1,206 cows had advanced registration (51%). The proportion of pedigree registered cows was relatively low but it gradually increased and reached a point of 20,847 cows (68%) between 2010 to 2017. Looking at the change in the EBV, the CWT improved from 4.992 kg to 9.885 kg, the EMA from 0.970 cm2 to 2.466 cm2, the BFT from -0.186 mm to -0.357 mm, and the MS from 0.328 to 0.559 points. As a result of genetic parameter estimation, the heritability of CWT, EMA, BFT, and MS were 0.587, 0.416, 0.476, and 0.571, respectively, and the accuracy of those were estimated to be 0.559, 0.551, 0.554, and 0.558, respectively. Selection of superior genetic breed and efficient improvement could be possible if cow ability verification is implemented by using the accurate pedigree of each individual in the farms.

10.
Chem Commun (Camb) ; 56(63): 9036-9039, 2020 Aug 06.
Article in English | MEDLINE | ID: mdl-32643719

ABSTRACT

Transition metal dichalcogenides and carbonitrides (TMDs and MXenes) have attracted great attention in electrochemistry due to their tunable electronic structures. Herein, a new compound of Nb2Se2C is designed as a "TMD-MXene"-like material. It exhibits better oxygen evolution reaction performance than most other reported TMDs, MXenes, and commercial electrocatalysts due to the enriched active sites and excellent conductivity.

11.
Chemistry ; 26(35): 7955-7960, 2020 Jun 23.
Article in English | MEDLINE | ID: mdl-32301529

ABSTRACT

Semiconductor nanocrystals of tunable shell/core configurations have great potential in photo-driven applications such as photoluminescence and photocatalysis, but few strategies realize a controllable synthesis with respect to both the size of the core and the shell with high crystallinity. Here, a new synthetic method based on cadmium cyanamide (CdNCN) nanoparticle anion exchange reactions was developed to access solid or hollow CdSe nanocrystals with tunable size and CdNCN@CdS heterostructures with modulated shell/core thickness. The gradual shift and narrow width of photoluminescence features demonstrate the high crystallinity and monodispersity of the resulting CdSe nanocrystals. In the CdNCN@CdS heterostructures, synergistic effects of the photocarrier separation is observed between the CdS shell and CdNCN core, which leads to great improvement in photocatalysis with optimized shell/core ratio.

12.
ACS Nano ; 13(9): 10818-10825, 2019 Sep 24.
Article in English | MEDLINE | ID: mdl-31469544

ABSTRACT

The synthesis of alloys with long-range atomic-scale ordering (ordered intermetallics) is an emerging field of nanochemistry. Ordered intermetallic nanoparticles are useful for a wide variety of applications such as catalysis, superconductors, and magnetic devices. However, the preparation of nanostructured ordered intermetallics is challenging in comparison to disordered alloys, hindering progress in material development. Herein, we report a process for converting colloidally synthesized ordered intermetallic PdBi2 to ordered intermetallic Pd3Bi nanoparticles under ambient conditions by electrochemical dealloying. The low melting point of PdBi2 corresponds to low vacancy formation energies, which enables the facile removal of the Bi from the surface while simultaneously enabling interdiffusion of the constituent atoms via a vacancy diffusion mechanism under ambient conditions. The resulting phase-converted ordered intermetallic Pd3Bi exhibits 11 times and 3.5 times higher mass activity and high methanol tolerance for the oxygen reduction reaction compared with Pt/C and Pd/C, respectively, which is the highest reported for a Pd-based catalyst, to the best of our knowledge. These results establish a key development in the synthesis of noble-metal-rich ordered intermetallic phases with high catalytic activity and set forth guidelines for the design of ordered intermetallic compounds under ambient conditions.

13.
Cell Cycle ; 18(19): 2524-2537, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31416393

ABSTRACT

At present, some researches have revealed the participation of long noncoding RNAs (lncRNAs) in liver cancer, but few of them have mentioned the role of CRNDE in drug resistance of liver cancer. Hence, this study is conducted to understand the role of CRNDE on liver cancer by regulating microRNA-33a (miR-33a) and high mobility group protein A2 (HMGA2) in liver cancer. First, drug-resistance model (HepG2 and BEL-7402) of human liver cancer cells was established. Then, CRNDE expression in drug-resistant cell lines (HepG2/adriamycin [ADM], BEL-7402/ADM) and parental cell lines (HepG2, BEL-7402) was detected. Furthermore, HepG2/ADM and BEL-7402/ADM cell lines with poor CRNDE expression or miR-33a overexpression was constructed. Next, drug-resistance index was calculated, and cell proliferation, apoptosis, migration, and invasion were detected, respectively. Then, the growth of tumor was observed in nude mice. Finally, the binding relationship between CRNDE and miR-33a and the targeting relationship between miR-33a and HMGA2 were verified. LncRNA CRNDE expressed highly in drug-resistant cells of liver cancer. Downregulated CRNDE and upregulated miR-33a-inhibited cells drug-resistance and promoted their apoptosis in liver cancer drug-resistant cells. CRNDE adsorbing and inhibiting miR-33a to promote HMGA2 in liver cancer drug-resistant cells by acting as a ceRNA. Silencing CRNDE or up-regulating miR-33a inhibited tumor growth of liver cancer in vivo. Our study provides evidence that downregulated CRNDE could upregulate miR-33a and inhibit HMGA2 expression, thus significantly promotes apoptosis of liver cancer cells and inhibiting its proliferation, migration, invasion and drug resistance.


Subject(s)
Antineoplastic Agents/pharmacology , Drug Resistance, Neoplasm/genetics , HMGA2 Protein/metabolism , Liver Neoplasms/metabolism , MicroRNAs/metabolism , RNA, Long Noncoding/metabolism , Animals , Apoptosis/drug effects , Apoptosis/genetics , Cell Line, Tumor , Cell Movement/drug effects , Cell Movement/genetics , Cell Proliferation/drug effects , Cell Proliferation/genetics , Down-Regulation , Gene Expression Regulation, Neoplastic/genetics , Gene Silencing , HMGA2 Protein/genetics , Humans , Liver Neoplasms/genetics , Mice , Mice, Inbred BALB C , Mice, Nude , MicroRNAs/genetics , RNA, Long Noncoding/genetics , Transplantation, Heterologous , Up-Regulation
14.
J Am Chem Soc ; 141(6): 2342-2347, 2019 Feb 13.
Article in English | MEDLINE | ID: mdl-30649876

ABSTRACT

Metal alloys with atomic scale ordering (ordered intermetallics) have emerged as a new class of high performance materials for mediating electrochemical reactions. However, ordered intermetallic nanostructures often require long synthesis times and/or high temperature annealing to form because a high-activation energy barrier for interdiffusion must be overcome for the constituent metals to equilibrate into ordered structures. Here we report the direct synthesis of metastable ordered intermetallic Pd31Bi12 at room-temperature in minutes via electrochemical deposition. Pd31Bi12 is highly active for the reduction of O2 to H2O, delivering specific activities over 35× higher than those of commercial Pt and Pd nanocatalysts, placing it as the most active Pd-based catalyst, to the best of our knowledge, reported under similar testing conditions. Stability tests demonstrate minimal loss of activity after 10,000 cycles, and a retention of intermetallic crystallinity. This study demonstrates a new method of preparing ordered intermetallics with extraordinary catalytic activity at room temperature, providing a new direction in catalyst discovery and synthesis.

15.
BMC Pharmacol Toxicol ; 19(1): 43, 2018 07 11.
Article in English | MEDLINE | ID: mdl-29996945

ABSTRACT

BACKGROUD: Cationic liposomes (CLs) can be used as non-viral vectors in gene transfer and drug delivery. However, the underlying molecular mechanism of its cytotoxicity has not been well elucidated yet. METHODS: We herein report a systems biology approach based on whole-transcriptome sequencing coupled with computational method to identify the predominant genes and pathways involved in the cytotoxicity of CLs in HepG2 cell line. RESULTS: Firstly, we validated the concentration-dependent cytotoxicity of CLs with an IC50 of 120 µg/ml in HepG2 exposed for 24 h. Subsequently, we used whole-transcriptome sequencing to identify 220 (77 up- and 143 down-regulated) differentially expressed genes (DEGs). Gene ontology (GO) and pathway analysis showed that these DEGs were mainly related to cholesterol, steroid, lipid biosynthetic and metabolic processes. Additionally, "key regulatory" genes were identified using gene act, pathway act and co-expression network analysis, and expression levels of 11 interested altered genes were confirmed by quantitative real time PCR. Interestingly, no cell cycle arrest was observed through flow cytometry. CONCLUSIONS: These data are expected to provide deep insights into the molecular mechanism of CLs cytotoxicity.


Subject(s)
Lipid Metabolism/drug effects , Liposomes/toxicity , Cell Survival/drug effects , Gene Expression Profiling , Gene Expression Regulation, Neoplastic/drug effects , Hep G2 Cells , Humans , Transcriptome/drug effects
16.
Angew Chem Int Ed Engl ; 55(8): 2830-4, 2016 Feb 18.
Article in English | MEDLINE | ID: mdl-26804980

ABSTRACT

Molybdenum ditelluride, MoTe2 , is emerging as an important transition-metal dichalcogenide (TMD) material because of its favorable properties relative to other TMDs. The 1T ' polymorph of MoTe2 is particularly interesting because it is semimetallic with bands that overlap near the Fermi level, but semiconducting 2H-MoTe2 is more stable and therefore more accessible synthetically. Metastable 1T '-MoTe2 forms directly in solution at 300 °C as uniform colloidal nanostructures that consist of few-layer nanosheets, which appear to exhibit an approx. 1 % lateral lattice compression relative to the bulk analogue. Density functional theory calculations suggest that small grain sizes and polycrystallinity stabilize the 1T ' phase in the MoTe2 nanostructures and suppress its transformation back to the more stable 2H polymorph through grain boundary pinning. Raman spectra of the 1T '-MoTe2 nanostructures exhibit a laser energy dependence, which could be caused by electronic transitions.

18.
Acc Chem Res ; 48(1): 56-64, 2015 Jan 20.
Article in English | MEDLINE | ID: mdl-25490673

ABSTRACT

CONSPECTUS: In the wake of the discovery of the remarkable electronic and physical properties of graphene, a vibrant research area on two-dimensional (2D) layered materials has emerged during the past decade. Transition metal dichalcogenides (TMDs) represent an alternative group of 2D layered materials that differ from the semimetallic character of graphene. They exhibit diverse properties that depend on their composition and can be semiconductors (e.g., MoS2, WS2), semimetals (e.g., WTe2, TiSe2), true metals (e.g., NbS2, VSe2), and superconductors (e.g., NbSe2, TaS2). The properties of TMDs can also be tailored according to the crystalline structure and the number and stacking sequence of layers in their crystals and thin films. For example, 2H-MoS2 is semiconducting, whereas 1T-MoS2 is metallic. Bulk 2H-MoS2 possesses an indirect band gap, but when 2H-MoS2 is exfoliated into monolayers, it exhibits direct electronic and optical band gaps, which leads to enhanced photoluminescence. Therefore, it is important to learn to control the growth of 2D TMD structures in order to exploit their properties in energy conversion and storage, catalysis, sensing, memory devices, and other applications. In this Account, we first introduce the history and structural basics of TMDs. We then briefly introduce the Raman fingerprints of TMDs of different layer numbers. Then, we summarize our progress on the controlled synthesis of 2D layered materials using wet chemical approaches, chemical exfoliation, and chemical vapor deposition (CVD). It is now possible to control the number of layers when synthesizing these materials, and novel van der Waals heterostructures (e.g., MoS2/graphene, WSe2/graphene, hBN/graphene) have recently been successfully assembled. Finally, the unique optical, electrical, photovoltaic, and catalytic properties of few-layered TMDs are summarized and discussed. In particular, their enhanced photoluminescence (PL), photosensing, photovoltaic conversion, and hydrogen evolution reaction (HER) catalysis are discussed in detail. Finally, challenges along each direction are described. For instance, how to grow perfect single crystalline monolayer TMDs without the presence of grain boundaries and dislocations is still an open question. Moreover, the morphology and crystal structure control of few-layered TMDs still requires further research. For wet chemical approaches and chemical exfoliation methods, it is still a significant challenge to control the lateral growth of TMDs without expansion in the c-axis direction. In fact, there is plenty of room in the 2D world beyond graphene. We envisage that with increasing progress in the controlled synthesis of these systems the unusual properties of mono- and few-layered TMDs and TMD heterostructures will be unveiled.

19.
Guang Pu Xue Yu Guang Pu Fen Xi ; 33(8): 2192-7, 2013 Aug.
Article in Chinese | MEDLINE | ID: mdl-24159874

ABSTRACT

A novel classification algorithm of hyperspectral imagery based on ant colony compositely optimizing support vector machine in spatial and spectral features was proposed. Two types of virtual ants searched for the bands combination with the maximum class separation distance and heterogeneous samples in spatial and spectral features alternately. The optimal characteristic bands were extracted, and bands redundancy of hyperspectral imagery decreased. The heterogeneous samples were eliminated form the training samples, and the distribution of samples was optimized in feature space. The hyperspectral imagery and training samples which had been optimized were used in classification algorithm of support vector machine, so that the class separation distance was extended and the accuracy of classification was improved. Experimental results demonstrate that the proposed algorithm, which acquires an overall accuracy 95.45% and Kappa coefficient 0.925 2, can obtain greater accuracy than traditional hyperspectral image classification algorithms.


Subject(s)
Algorithms , Artificial Intelligence , Image Enhancement/methods , Spectrum Analysis/methods , Support Vector Machine
20.
FEBS J ; 280(9): 2027-41, 2013 May.
Article in English | MEDLINE | ID: mdl-23461856

ABSTRACT

We report that the epidermal growth factor receptor (EGFR) pathway plays a critical role in regulating cancer stem-like cells (CSCs) in nasopharyngeal carcinoma (NPC), one of the most common malignant tumors in Southeast Asia. Effects of EGFR on maintaining CSCs are mainly mediated by AKT signaling, and ß-catenin is responsible for governing CSC properties in response to EGFR/AKT activation. Significantly, CSCs are enriched by cisplatin and decreased by gefitinib in NPC xenograft models. Upon reimplantation in secondary mice, tumor cells derived from cisplatin-treated mice grew rapidly, whereas regrowth of tumor cells from gefitinib-treated mice was severely diminished. We further demonstrate that expression of EGFR correlates with expression of ß-catenin and Nanog in primary tumor specimens from NPC patients. These findings provide mechanistic and preclinical evidence supporting the use of gefitinib alone or in combination with a chemotherapeutic agent in first-line therapy for patients with NPC. In addition, our results suggest that targeting ß-catenin represents a rational clinical modality for patients whose tumors harbor activated EGFR or AKT.


Subject(s)
Antineoplastic Agents/pharmacology , Carcinoma/pathology , ErbB Receptors/metabolism , Nasopharyngeal Neoplasms/pathology , Neoplastic Stem Cells/metabolism , Quinazolines/pharmacology , Signal Transduction , Animals , Carcinoma/drug therapy , Carcinoma/metabolism , Cell Line, Tumor , Cell Proliferation , Cell Survival/drug effects , Cell Transformation, Neoplastic/metabolism , Cisplatin/pharmacology , ErbB Receptors/antagonists & inhibitors , ErbB Receptors/genetics , Gefitinib , Gene Knockdown Techniques , Homeodomain Proteins/metabolism , Humans , Mice , Mice, Inbred BALB C , Mice, Nude , Nanog Homeobox Protein , Nasopharyngeal Carcinoma , Nasopharyngeal Neoplasms/drug therapy , Nasopharyngeal Neoplasms/metabolism , Neoplasm Transplantation , Neoplastic Stem Cells/drug effects , Proto-Oncogene Proteins c-akt/metabolism , Side-Population Cells/drug effects , Side-Population Cells/metabolism , Spheroids, Cellular/metabolism , Spheroids, Cellular/physiology , Xenograft Model Antitumor Assays , beta Catenin/genetics , beta Catenin/metabolism
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