40 results on '"Muhan Chen"'
Search Results
2. Environment Knowledge-Aided Massive MIMO Feedback Codebook Enhancement Using Artificial Intelligence
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Jiajia Guo, Chao-Kai Wen, Muhan Chen, and Shi Jin
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Electrical and Electronic Engineering - Published
- 2022
3. Supplementary Figure S2. Genetic tools used for dissecting Il6/Stat3/Myc signaling. from MYC Drives Pten/Trp53-Deficient Proliferation and Metastasis due to IL6 Secretion and AKT Suppression via PHLPP2
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Lloyd C. Trotman, Brian D. Robinson, Carlos Cordon-Cardo, Mireia Castillo-Martin, John E. Wilkinson, Raffaella Sordella, Muhan Chen, David Kleinman, Tumas Beinortas, David Ding, Christof Fellmann, Serif Senturk, Victoria M.Y. Wang, Daniel V. DeMarco, Kaitlin Watrud, Tali Herzka, Hyejin Cho, and Dawid G. Nowak
- Abstract
Supplementary Figure S2. Genetic tools used for dissecting Il6/Stat3/Myc signaling. (A) Scheme of conditional alleles and PCR primers used for assessing the recombination of Pten/ Trp53 genes. (B) Senescence-specific ß-gal staining is detected after Pten loss but not after Pten/Trp53 co-deletion. Scale Bar, 200 μm.
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- 2023
4. Supplementary Figure S1. Copy Number Alteration analysis of human prostate cancer confirms loss of PTEN and TP53 genes as a genetic hallmark of metastatic prostate cancer. from MYC Drives Pten/Trp53-Deficient Proliferation and Metastasis due to IL6 Secretion and AKT Suppression via PHLPP2
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Lloyd C. Trotman, Brian D. Robinson, Carlos Cordon-Cardo, Mireia Castillo-Martin, John E. Wilkinson, Raffaella Sordella, Muhan Chen, David Kleinman, Tumas Beinortas, David Ding, Christof Fellmann, Serif Senturk, Victoria M.Y. Wang, Daniel V. DeMarco, Kaitlin Watrud, Tali Herzka, Hyejin Cho, and Dawid G. Nowak
- Abstract
Supplementary Figure S1. Copy Number Alteration analysis of human prostate cancer confirms loss of PTEN and TP53 genes as a genetic hallmark of metastatic prostate cancer. (A) Co-deletion frequency for PTEN and TP53 in metastatic and primary prostate cancer samples. (B) Co-deletion frequency for PTEN and TP53 in metastatic and primary prostate cancer samples. (C) Co-deletion frequency for PTEN and TP53 in metastatic prostate cancer samples . (D) Gene maps of the conditional alleles used for ablation of Pten/ Trp53 genes and activation of tdTomato. Cre leads to recombination of loxP sites in the Pten/Trp53 genes and excision of a STOP cassette that leads to activation of the fluorescence protein tdTomato. (E) Analysis of tdTomato-positive cells using Guava flow cytometry system show that AdCre leads to activation of tdTomato in over 95% percent of cells without the need for selection. (F) Activation of tdTomato can be easily visualized using fluorescence microscopy.
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- 2023
5. Supplementary Figure S7. Pathway to Pten/ Trp53 deficient prostate metastasis and therapy resistance. from MYC Drives Pten/Trp53-Deficient Proliferation and Metastasis due to IL6 Secretion and AKT Suppression via PHLPP2
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Lloyd C. Trotman, Brian D. Robinson, Carlos Cordon-Cardo, Mireia Castillo-Martin, John E. Wilkinson, Raffaella Sordella, Muhan Chen, David Kleinman, Tumas Beinortas, David Ding, Christof Fellmann, Serif Senturk, Victoria M.Y. Wang, Daniel V. DeMarco, Kaitlin Watrud, Tali Herzka, Hyejin Cho, and Dawid G. Nowak
- Abstract
Supplementary Figure S7. Pathway to Pten/ Trp53 deficient prostate metastasis and therapy resistance. Pten-loss triggers PIP3 signaling to activate AKT, which prompts activation of the p53/ p21/ p16 tumor suppressors and senescence arrest. Suppression and loss of p53 in this context results in cell proliferation and Il6 secretion. Il6 signals both auto and paracrine to activate Myc via the Jak/Stat pathway. Myc induces the Phlpp2 phosphatase which creates a negative feedback loop by dampening Akt activation. Metastases (and castration-resistant tumors) select for increased Myc expression (and gene amplification, and Akt inactivation, demonstrating that Myc supersedes the need for Akt in lethal prostate cancer.
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- 2023
6. Supplementary Figure S3. Tools used for targeting of Il6 and Stat3. from MYC Drives Pten/Trp53-Deficient Proliferation and Metastasis due to IL6 Secretion and AKT Suppression via PHLPP2
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Lloyd C. Trotman, Brian D. Robinson, Carlos Cordon-Cardo, Mireia Castillo-Martin, John E. Wilkinson, Raffaella Sordella, Muhan Chen, David Kleinman, Tumas Beinortas, David Ding, Christof Fellmann, Serif Senturk, Victoria M.Y. Wang, Daniel V. DeMarco, Kaitlin Watrud, Tali Herzka, Hyejin Cho, and Dawid G. Nowak
- Abstract
Supplementary Figure S3. Tools used for targeting of Il6 and Stat3. (A) Il6 neutralizing antibody specifically decreases the proliferation of Pten/ Trp53 deficient primary MEFs. ANOVA, Dunnett's post-hoc test, **p
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- 2023
7. Supplementary Figure S4. Activation of Stat3/Myc signaling is specific to Ptenpc-/-; Trp53pc-/-prostate and leads to stromal expansion. from MYC Drives Pten/Trp53-Deficient Proliferation and Metastasis due to IL6 Secretion and AKT Suppression via PHLPP2
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Lloyd C. Trotman, Brian D. Robinson, Carlos Cordon-Cardo, Mireia Castillo-Martin, John E. Wilkinson, Raffaella Sordella, Muhan Chen, David Kleinman, Tumas Beinortas, David Ding, Christof Fellmann, Serif Senturk, Victoria M.Y. Wang, Daniel V. DeMarco, Kaitlin Watrud, Tali Herzka, Hyejin Cho, and Dawid G. Nowak
- Abstract
Supplementary Figure S4. Activation of Stat3/Myc signaling is specific to Ptenpc-/-; Trp53pc-/-prostate and leads to stromal expansion. (A) H&E analysis of prostates from all studied genotypes reveals massive stromal expansion after co-deletion of Pten and Trp53. IHC analysis confirms stromal pStat3/ Myc activation specifically in Ptenpc-/-; Trp53pc-/- prostate. Note that pAkt activation is restricted to gland, consistent with triggering paracrine Il6/Stat3/Myc activation. Scale Bars, 100 μm. (B) Pten is present in the stroma of Ptenpc-/-; Trp53pc-/- prostates confirming that the expansion of stroma is not driven by spurious Pten/Trp53 recombination. (C) Proliferation in the Ptenpc-/- glands correlates with Akt activation, in contrast to Ptenpc-/-; Trp53pc-/- glands, where it correlates with Stat3/ Myc staining.
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- 2023
8. Supplementary Figure S6. Ar expression in primary and metastatic tumors. from MYC Drives Pten/Trp53-Deficient Proliferation and Metastasis due to IL6 Secretion and AKT Suppression via PHLPP2
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Lloyd C. Trotman, Brian D. Robinson, Carlos Cordon-Cardo, Mireia Castillo-Martin, John E. Wilkinson, Raffaella Sordella, Muhan Chen, David Kleinman, Tumas Beinortas, David Ding, Christof Fellmann, Serif Senturk, Victoria M.Y. Wang, Daniel V. DeMarco, Kaitlin Watrud, Tali Herzka, Hyejin Cho, and Dawid G. Nowak
- Abstract
Supplementary Figure S6. Ar expression in primary and metastatic tumors. (A) IHC analysis of the Ar status in RapidCaP lesions shows no significant Ar staining (left panel) while most prostate glands show strong nuclear Ar staining. (B) The wild type and mutant prostates from Probasin-Cre animals show strong Ar staining.
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- 2023
9. Supplementary Figure Legends from MYC Drives Pten/Trp53-Deficient Proliferation and Metastasis due to IL6 Secretion and AKT Suppression via PHLPP2
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Lloyd C. Trotman, Brian D. Robinson, Carlos Cordon-Cardo, Mireia Castillo-Martin, John E. Wilkinson, Raffaella Sordella, Muhan Chen, David Kleinman, Tumas Beinortas, David Ding, Christof Fellmann, Serif Senturk, Victoria M.Y. Wang, Daniel V. DeMarco, Kaitlin Watrud, Tali Herzka, Hyejin Cho, and Dawid G. Nowak
- Abstract
Supplementary Figure Legends from MYC Drives Pten/Trp53-Deficient Proliferation and Metastasis due to IL6 Secretion and AKT Suppression via PHLPP2
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- 2023
10. Data from High-throughput Loss-of-Heterozygosity Study of Chromosome 3p in Lung Cancer Using Single-Nucleotide Polymorphism Markers
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Xin-Yuan Guan, Pak C. Sham, Minyue Zhang, Muhan Chen, You Qiang Song, Yan Fang, Kevin K.W. Chu, Li Fu, Mandy Y.M. Ng, Daniel T.T. Chua, Phoebe K.M. Ng, William Mak, and Amy L.S. Tai
- Abstract
Loss of DNA copy number at the short arm of chromosome 3 is one of the most common genetic changes in human lung cancer, suggesting the existence of one or more tumor suppressor genes (TSG) at 3p. To identify most frequently deleted regions and candidate TSGs within these regions, a recently developed single-nucleotide polymorphism (SNP)-mass spectrometry-genotyping (SMSG) technology was applied to investigate the loss of heterozygosity (LOH) in 30 primary non–small-cell lung cancers. A total of 386 SNP markers that spanned a region of 70 Mb at 3p, from 3pter to 3p14.1, were selected for LOH analysis. The average intermarker distance in the present study is ∼180 kb. Several frequently deleted regions, including 3p26.3, 3p25.3, 3p24.1, 3p23, and 3p21.1, were found. Several candidate TSGs within these frequently detected LOH regions have been found, including APG7L at 3p25.3, CLASP2 at 3p23, and CACNA2D3 at 3p21.1. This study also showed that SMSG technology is a very useful approach to rapidly define the minimal deleted region and to identify target TSGs in a given cancer. (Cancer Res 2006; 66(8): 4133-8)
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- 2023
11. Supplementary Table 2 from High-throughput Loss-of-Heterozygosity Study of Chromosome 3p in Lung Cancer Using Single-Nucleotide Polymorphism Markers
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Xin-Yuan Guan, Pak C. Sham, Minyue Zhang, Muhan Chen, You Qiang Song, Yan Fang, Kevin K.W. Chu, Li Fu, Mandy Y.M. Ng, Daniel T.T. Chua, Phoebe K.M. Ng, William Mak, and Amy L.S. Tai
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Supplementary Table 2 from High-throughput Loss-of-Heterozygosity Study of Chromosome 3p in Lung Cancer Using Single-Nucleotide Polymorphism Markers
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- 2023
12. Supplementary Table 1 from High-throughput Loss-of-Heterozygosity Study of Chromosome 3p in Lung Cancer Using Single-Nucleotide Polymorphism Markers
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Xin-Yuan Guan, Pak C. Sham, Minyue Zhang, Muhan Chen, You Qiang Song, Yan Fang, Kevin K.W. Chu, Li Fu, Mandy Y.M. Ng, Daniel T.T. Chua, Phoebe K.M. Ng, William Mak, and Amy L.S. Tai
- Abstract
Supplementary Table 1 from High-throughput Loss-of-Heterozygosity Study of Chromosome 3p in Lung Cancer Using Single-Nucleotide Polymorphism Markers
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- 2023
13. Recovery of Pd(II) from Hydrochloric Acid Medium by Solvent Extraction–Direct Electrodeposition Using Hydrophilic/Hydrophobic ILs
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Shunling Li, Muhan Chen, Min Shao, Ci Jin, and Zhangjie Huang
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Chemistry ,General Chemical Engineering ,Extraction (chemistry) ,Hydrochloric acid ,General Chemistry ,C4mim ,Article ,chemistry.chemical_compound ,Ionic liquid ,Hydrophilic hydrophobic ,Solvent extraction ,QD1-999 ,Nuclear chemistry - Abstract
Mixed [C8bet]Br/[C4mim][NTf2] ionic liquids were used as a new extraction system to extract Pd(II) from multimetal-ion solutions. The separation factors KPd/M (M: Cu, Fe, Ni, Zn, Co) are greater than 103. Thiourea was found to be an effective stripping agent. After three cycles, the recovery efficiency was higher than 91.0%. Direct electrodeposition of palladium from the mixed ionic liquid phase was also studied. The Pd(II) complex in [C8bet]Br/[C4mim][NTf2] system was studied by cyclic voltammetry at 348 K. The results indicate the existence of three types of Pd(II) complex in the [C8bet]Br/[C4mim][NTf2] system, leading to three reductive waves. The reduction of Pd(II) to Pd(0) in this system is irreversible. A uniform black coating was obtained by constant-potential deposition at −1.7 V on a nickel foil, confirmed to be palladium metal by energy-dispersive spectrometry, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy analyses. After three cycles of continuous extraction–electrodeposition, over 90.0% of palladium was recovered.
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- 2020
14. AI enabled wireless communications with real channel measurements: Channel feedback
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Muhan Chen, Tingting Yang, Jiajia Guo, Shi Jin, Weiming Duan, Xiangyi Li, Haowen Wang, Jiang Peiwen, and Quan Yu
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Artificial neural network ,Computer Networks and Communications ,Computer science ,business.industry ,Communications system ,Channel feedback ,Power (physics) ,Computer engineering ,Systems design ,Wireless ,Electrical and Electronic Engineering ,Baseline (configuration management) ,business ,Communication channel - Abstract
Artificial intelligence (AI) has shown great potential in wireless communications. AI-empowered communication algorithms have beaten many traditional algorithms through simulations. However, the existing works just use the simulated datasets to train and test the algorithms, which can not represent the power of AI in practical communication systems. Therefore, Peng Cheng Laboratory holds an AI competition, National Artificial Intelligence Competition (NAIC): AI+wireless communications, in which one of the topics is AI-empowered channel feedback system design using practical measurements. In this paper, we give a baseline neural network design, QuanCsiNet, for this competition, and the details of the channel measurements. QuanCsiNet shows excellent performance on channel feedback and the complexity of the neural networks is also given.
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- 2020
15. Regenerable neodymium-doped zirconium-based MOF adsorbents for the effective removal of phosphate from water
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Guoting Luo, Zhuangzhuang Bi, Chali Liu, Zhaoneng Wan, Zhihong Chen, Muhan Chen, and Zhangjie Huang
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Process Chemistry and Technology ,Chemical Engineering (miscellaneous) ,Pollution ,Waste Management and Disposal - Published
- 2022
16. AI-enhanced Codebook-based CSI Feedback in FDD Massive MIMO
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Jiajia Guo, Chao-Kai Wen, Muhan Chen, and Shi Jin
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- 2021
17. Deep Learning-based Implicit CSI Feedback in Massive MIMO
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Muhan Chen, Jiajia Guo, Chao-Kai Wen, Shi Jin, Geoffrey Ye Li, and Ang Yang
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Signal Processing (eess.SP) ,FOS: Computer and information sciences ,Computer Science - Machine Learning ,Computer Science - Information Theory ,Information Theory (cs.IT) ,FOS: Electrical engineering, electronic engineering, information engineering ,Data_CODINGANDINFORMATIONTHEORY ,Electrical Engineering and Systems Science - Signal Processing ,Electrical and Electronic Engineering ,Machine Learning (cs.LG) - Abstract
Massive multiple-input multiple-output can obtain more performance gain by exploiting the downlink channel state information (CSI) at the base station (BS). Therefore, studying CSI feedback with limited communication resources in frequency-division duplexing systems is of great importance. Recently, deep learning (DL)-based CSI feedback has shown considerable potential. However, the existing DL-based explicit feedback schemes are difficult to deploy because current fifth-generation mobile communication protocols and systems are designed based on an implicit feedback mechanism. In this paper, we propose a DL-based implicit feedback architecture to inherit the low-overhead characteristic, which uses neural networks (NNs) to replace the precoding matrix indicator (PMI) encoding and decoding modules. By using environment information, the NNs can achieve a more refined mapping between the precoding matrix and the PMI compared with codebooks. The correlation between subbands is also used to further improve the feedback performance. Simulation results show that, for a single resource block (RB), the proposed architecture can save 25.0% and 40.0% of overhead compared with Type I codebook under two antenna configurations, respectively. For a wideband system with 52 RBs, overhead can be saved by 30.7% and 48.0% compared with Type II codebook when ignoring and considering extracting subband correlation, respectively., Comment: This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessible
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- 2021
- Full Text
- View/download PDF
18. Separation and Recovery of Iridium(Ⅳ) from a Simulated Secondary Resource Leachate by Extraction - Electrodeposition
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Mei Fan, Shunling Li, Hui Deng, Xiaoguo Zhang, Guoting Luo, zhangjie Huang, and Muhan Chen
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History ,Polymers and Plastics ,Business and International Management ,Industrial and Manufacturing Engineering - Published
- 2021
19. China's plastic import ban increases prospects of environmental impact mitigation of plastic waste trade flow worldwide
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Christian Doh Dinga, Yiling Xie, Zongguo Wen, and Muhan Chen
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Natural resource economics ,020209 energy ,Science ,General Physics and Astronomy ,Developing country ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Article ,Environmental impact ,0202 electrical engineering, electronic engineering, information engineering ,Environmental impact assessment ,China ,Life-cycle assessment ,0105 earth and related environmental sciences ,Multidisciplinary ,biology ,Global warming ,Euros ,Climate-change policy ,General Chemistry ,biology.organism_classification ,Business and industry ,Sustainability ,Plastic waste ,Business - Abstract
Since the late 1990s, the trend of plastic waste shipment from developed to developing countries has been increasing. In 2017, China announced an unprecedented ban on its import of most plastic waste, resulting in a sharp decline in global plastic waste trade flow and changes in the treatment structure of countries, whose impacts on global environmental sustainability are enormous but yet unexamined. Here, through the life cycle assessment (LCA) method, we quantified the environmental impacts of changes in the flow patterns and treatment methods of 6 types of plastic waste in 18 countries subsequent to the ban. In the short term, the ban significantly improved four midpoint indicators of environmental impact, albeit contributed to global warming. An annual saving of about 2.35 billion euros of eco-cost was realized, which is equivalent to 56% of plastic waste global trade value in 2017. To achieve global environmental sustainability in the long run, countries should gradually realize the transition from export to domestic management, and from landfill to recycling, which would realize eco-costs savings of about 1.54–3.20 billion euros., China announced a ban on its import of most plastic waste in 2017, resulting in an impact on global environmental sustainability. Here the authors quantify the environmental impacts of changes in the flow patterns and treatment methods of 6 types of plastic waste in 18 countries subsequent to the ban.
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- 2020
20. Facile and Green Approach To Prepare Nanostructured Au@MnO2 and Its Applications for Catalysis and Fluorescence Sensing of Glutathione in Human Blood
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Genfu Zhao, Wei Gao, Xiaojian Zhou, Xiaoguang Xie, Long Yang, Muhan Chen, Xu Zhou, and Guanben Du
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Detection limit ,Materials science ,Nanocomposite ,Renewable Energy, Sustainability and the Environment ,General Chemical Engineering ,Composite number ,Nanotechnology ,02 engineering and technology ,General Chemistry ,Glutathione ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Catalysis ,chemistry.chemical_compound ,chemistry ,Colloidal gold ,Environmental Chemistry ,Degradation (geology) ,0210 nano-technology ,Selectivity - Abstract
The increasingly serious environmental problems make it urgent to develop a new type of sustainable green material which can degrade pollutants and monitor human health. However, the traditional preparation methods are frequently limited by tedious operations, high-energy consumption, and massive pollution. Herein, we present a facile and green method for preparation of MnO2 nanoflakes mediated by macrocyclic molecule calix[8]arene. The MnO2 nanoflakes in situ grew on the preformed gold nanoparticles, forming an impressive core–shell Au@MnO2 flake-like nanocomposite. The catalytic properties of Au@MnO2 composite for reduction of 4-NP and degradation of MB were 2.4 and 187 times better than commercial Pd/C, respectively. Meanwhile, the as-synthesized Au@MnO2 nanocomposite exhibited specially excellent sensitivity and selectivity for detection of GSH with a limit of detection (LOD) of 0.11 μM. The core–shell nanostructured Au@MnO2 shows great potential value for the sustainable development of the environmen...
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- 2018
21. Selective recovery of palladium and rhodium by combined extraction and photocatalytic reduction
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Jing Chen, Guoting Luo, Mei Fan, Xiaoguang Xie, Shunling Li, Zhangjie Huang, and Muhan Chen
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Aqueous solution ,Extraction (chemistry) ,chemistry.chemical_element ,Filtration and Separation ,02 engineering and technology ,021001 nanoscience & nanotechnology ,C4mim ,Analytical Chemistry ,Rhodium ,chemistry.chemical_compound ,020401 chemical engineering ,chemistry ,Reagent ,Ionic liquid ,0204 chemical engineering ,Solubility ,0210 nano-technology ,Nuclear chemistry ,Palladium - Abstract
In this study, four novel functionalized ionic liquids ([C4mim][DDTC], [C5mim][DDTC], [C6mim][DDTC], and [BMPip][DDTC]) were synthesized and used for the selective extraction of Pd(II) from an HCl medium containing Pt(IV), Pd(II), and Rh(III). The extraction mechanism was investigated using Job’s plots, UV–Vis, SXRD, and MS analysis. A mechanistic investigation revealed the formation of hydrophobic extraction complexes Pd(DDTC)2 and PdClDDTC via coordination between [DDTC]− and Pd(II). In addition, the solubility and polarity of the solutes were investigated using DFT calculations to determine the optimal extractant and diluent. From the results of the theoretical analysis, [C5mim][DDTC]/CHCl3 was selected as the optimum system for the selective extraction of Pd(II). The effects that factors have on Pd(II) extraction, including temperature, [C5mim][DDTC] amount, HCl concentration, and O/A ratio, were investigated and optimized using single-factor and response surface experiments. Under the optimized conditions, Pd(II) extraction efficiencies were higher than 99%, and the separation factors (βPd(II)/Pt(IV) and βPd(II)/Rh(III)) were greater than 104. After extraction, Pd and Rh were directly recovered from the organic and aqueous phases via photocatalytic reduction, respectively. TEM, XPS, and PXRD results revealed that the resulting nanoparticles were Rh(0) or Pd(0). The recovery of Pd and Rh exceeded 95%. Overall, a simple hydrometallurgical process with low reagent consumption was developed to yield nanometer-scale Pd(0) and Rh(0) from simulated secondary resource leaching solutions.
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- 2021
22. Microemulsion system constructed with a new cyano-functionalized ionic liquid for the extraction of Pd(II) and preparation of palladium nanoparticles
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Ci Jin, Guoting Luo, Mei Fan, Zhangjie Huang, Min Shao, and Muhan Chen
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Cyclohexane ,Extraction (chemistry) ,Filtration and Separation ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Analytical Chemistry ,chemistry.chemical_compound ,020401 chemical engineering ,chemistry ,Bromide ,Ionic liquid ,Microemulsion ,Tributyl phosphate ,0204 chemical engineering ,Fourier transform infrared spectroscopy ,0210 nano-technology ,Hydrate ,Nuclear chemistry - Abstract
In this study, based on a cyano-functionalized ionic liquid, 1-nitrile-1-octylpyrrole bromide ([C8Y3Pr]Br), a [C8Y3Pr]Br/cyclohexane/tributyl phosphate (TBP)/NaCl microemulsion system was constructed and used for the extraction of Pd(II) and preparation of Pd nanoparticles from multimetal solutions. The key extraction parameters including vibration time, [C8Y3Pr]Br concentration, phase ratio (RW/O), and HCl concentration were evaluated. Compared with other ionic-liquid microemulsion systems, the cyano-functionalized ionic liquid [C8Y3Pr]Br microemulsion system showed excellent extraction performance for Pd(II). Almost all Pd(II) was extracted (>98.0%) from a multimetal solution using the microemulsion system, while the separation factors (βPd/M) of [C8Y3Pr]Br-based microemulsions for Pd(II) with Cu2+, Fe3+, Ni2+, Zn2+, Co2+, and Mg2+ exceeded 1.0 × 103. The mechanism extracting Pd(II) using [C8Y3Pr]Br was confirmed to be an anion-exchange reaction via Job’s method, spectral analysis (UV, FTIR), and DFT calculations. Alcohols and hydrazine hydrate were used as demulsifiers, and Pd nanoparticles were directly obtained from the microemulsion phase. The Pd nanoparticles were identified by TEM, XPS, and XRD analyses. The chemical structures of extracted species based on the microemulsion system and the mechanism of demulsification of alcohols were studied. Thus, an effective new process was developed in this study for the direct preparation of Pd nanoparticles from mixed metal solutions via solvent extraction.
- Published
- 2021
23. Facile and clean separation of Pb(II) from soil and recycling by pH-triggered microbial technology
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Qing Qu, Xiao-Hong Li, Yixiu Dai, Shunling Li, Lei Li, Muhan Chen, and Rui Huang
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Environmental remediation ,General Chemical Engineering ,Nanoparticle ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Industrial and Manufacturing Engineering ,0104 chemical sciences ,Catalysis ,chemistry.chemical_compound ,chemistry ,Yield (chemistry) ,Soil water ,Ph triggered ,Environmental Chemistry ,0210 nano-technology ,Surfactin ,Mesoporous material ,Nuclear chemistry - Abstract
Developing an efficient method to recover and reuse soil-base lead (Pb) poses significant challenges. Herein, we designed a remediation method to achieve the dual goal of separating and reusing Pb from soil based on Bacillus megaterium-secreted surfactin with pH-response. Under weakly alkaline, B. megaterium-secreted surfactin efficiently captured Pb(II) from soil and also converted it into biological Pb/PbO nanoparticles (bio-Pb/PbO NPs). Further, surfactin’s sensitivity to pH enables bio-Pb/PbO NPs to be readily separated from the soil through simple pH adjustments. The highest yield of bio-Pb/PbO NPs (77.54%) was achieved at an initial concentration of 1 mg/g Pb(II). The recovered bio-Pb/PbO NPs showed a mesoporous structure and an average size of ~47 nm. More importantly, bio-Pb/PbO NPs exhibited highly efficient catalytic activity for the hydrogen evolution reaction in 1 M KOH. These results demonstrated that this method efficiently recovered and converted Pb into high value-added NPs, and was thereby a sustainable and feasible technique for Pb(II) recovery and reuse. As such, this methodology offers a new, efficient, and practical approach for sustainable remediation of heavy metal contamination in soils.
- Published
- 2021
24. Hydrophobic phosphonium-based ionic liquids as novel extractants for palladium(II) recovery from alkaline cyanide solutions
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Xiaoguang Xie, Min Shao, Zhangjie Huang, Ci Jin, Guoting Luo, Muhan Chen, and Mei Fan
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Ion exchange ,Cyanide ,Extraction (chemistry) ,Infrared spectroscopy ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,Bromide ,Ionic liquid ,Materials Chemistry ,Phosphonium ,Physical and Theoretical Chemistry ,0210 nano-technology ,Spectroscopy ,Nuclear chemistry ,Palladium - Abstract
Although phosphonium-based ionic liquids (ILs) have become popular green solvents for the separation of precious metals, these solvents have not been used thus far to recover Pd(II) from alkaline cyanide solutions. In this study, three novel phosphonium-based ILs, viz. tributyl(2-ethylhexyl) phosphonium bromide (TBEHPB), trioctyl (2-ethylhexyl) phosphonium bromide (TOEHPB), and trioctyl undecyl phosphonium bromide (TOUPB), were synthesized, respectively, and these ILs were used for the recovery of Pd(CN)42− for the first time. With the increase in the length of the alkyl chain in the phosphonium cation, the extraction percentage of Pd(II) increased. Under optimum conditions (i.e., contact time of 5 min, pH of 10.5, and temperature of 298 K), the TOUPB system exhibited a Pd(II) extraction percentage of greater than 99.0%. Furthermore, the TOUPB system exhibited excellent selectivity for Pd(II) in a mixed solution (separation factors of βPd/Fe and βPd/Co were greater than 2.0 × 103). The Pd(II) recovery percentage was still greater than 90.0% after five consecutive extraction-stripping cycles. The Job’s method, infrared spectroscopy, mass spectrometry, nuclear magnetic resonance spectroscopy, and UV–vis spectroscopy revealed that the extraction mechanism is ion exchange. The supramolecular structure of the extraction complex was established on the basis of density functional theory (DFT) calculations and Karl Fischer titration, and the extraction mechanism was further described at the molecular structure level. This study provides a new process for recovering Pd(II) from an alkaline cyanide medium.
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- 2021
25. The nuclear transport receptor Importin-11 is a tumor suppressor that maintains PTEN protein
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Lorna Wills, Saya H. Ebbesen, Wu Zheng, Navneet Narula, Scott Powers, Kendra S. Plafker, Lloyd C. Trotman, Tali Herzka, Brian D. Robinson, Kaitlin Watrud, Vivek Mittal, Brendon M. Stiles, Nasser K. Altorki, Carlos Stahlhut, Dawid G. Nowak, John E. Wilkinson, Abu Nasar, Raffaella Sordella, Matthias Minderer, Carlos Cordon-Cardo, Mireia Castillo-Martin, Martha E. Zeeman, Alexandra Ambrico, Muhan Chen, Victoria M.-Y. Wang, and Scott M. Plafker
- Subjects
0301 basic medicine ,Cytoplasm ,Lung Neoplasms ,Phosphatase ,Receptors, Cytoplasmic and Nuclear ,Importin ,Biology ,Article ,Cell Line ,law.invention ,Metastasis ,Mice ,03 medical and health sciences ,law ,Cell Line, Tumor ,medicine ,Animals ,Humans ,Tensin ,PTEN ,Receptor ,Research Articles ,Cell Nucleus ,Tumor Suppressor Proteins ,PTEN Phosphohydrolase ,Cell Biology ,beta Karyopherins ,medicine.disease ,3. Good health ,030104 developmental biology ,Ubiquitin-Conjugating Enzymes ,Cancer research ,biology.protein ,Suppressor ,Adenocarcinoma ,HeLa Cells - Abstract
Reduced PTEN protein is linked to tumorigenesis. Here, Chen et al. show that the nuclear transport receptor Importin-11 separates PTEN from degradation machinery. IPO11 mutant mice exhibit PTEN degradation, lung adenocarcinoma, and prostate neoplasia. In human prostatectomy patients, IPO11 status predicts disease recurrence and metastasis., Phosphatase and tensin homologue (PTEN) protein levels are critical for tumor suppression. However, the search for a recurrent cancer-associated gene alteration that causes PTEN degradation has remained futile. In this study, we show that Importin-11 (Ipo11) is a transport receptor for PTEN that is required to physically separate PTEN from elements of the PTEN degradation machinery. Mechanistically, we find that the E2 ubiquitin-conjugating enzyme and IPO11 cargo, UBE2E1, is a limiting factor for PTEN degradation. Using in vitro and in vivo gene-targeting methods, we show that Ipo11 loss results in degradation of Pten, lung adenocarcinoma, and neoplasia in mouse prostate with aberrantly high levels of Ube2e1 in the cytoplasm. These findings explain the correlation between loss of IPO11 and PTEN protein in human lung tumors. Furthermore, we find that IPO11 status predicts disease recurrence and progression to metastasis in patients choosing radical prostatectomy. Thus, our data introduce the IPO11 gene as a tumor-suppressor locus, which is of special importance in cancers that still retain at least one intact PTEN allele.
- Published
- 2017
26. Separation and recovery of Pd(II) and Pt(II) from cyanide liquors of Pd-Pt flotation concentrate via solvent extraction
- Author
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Jing Chen, Wu Shengjie, Zhangjie Huang, Min Jun Chen, and Muhan Chen
- Subjects
Stripping (chemistry) ,Renewable Energy, Sustainability and the Environment ,General Chemical Engineering ,Cyanide ,Organic Chemistry ,Extraction (chemistry) ,Inorganic chemistry ,chemistry.chemical_element ,02 engineering and technology ,Thiodiglycol ,021001 nanoscience & nanotechnology ,Pollution ,020501 mining & metallurgy ,Inorganic Chemistry ,chemistry.chemical_compound ,Fuel Technology ,0205 materials engineering ,chemistry ,Bromide ,Ammonium thiocyanate ,0210 nano-technology ,Platinum ,Waste Management and Disposal ,Biotechnology ,Palladium - Abstract
BACKGROUND Thus far, separation and recovery of Pd(CN)42- and Pt(CN)42- from cyanide liquors have not been reported. In this study, the process of co-extracting and separating Pd(II) and Pt(II) over Fe(III), Cu(I), Co(III), and Ni(I) from alkaline cyanide liquors was investigated. RESULTS The results showed that almost all Pd(II) and Pt(II) (>98.0%) could be simultaneously extracted by phenoxyethyl dimethyl palmitylammonium bromide (PDPB), whereas Fe(III), Cu(I), Co(III), and Ni(I) was below 3.0% under optimum conditions. Furthermore, Pd(CN)42- and Pt(CN)42- were separated and recovered by the two-step stripping process. First, Pd(CN)42- in mixed organic phase was stripped by a 2.0 mol L−1 ammonium thiocyanate solution. The stripping percentage of Pd(CN)42- was >98%, whereas the stripped Pt(CN)42- was below 1%. Second, more than 97.5% Pt(CN)42- in the loaded organic phase could be stripped using 1.0 mol L−1 thiodiglycol solution. Recovery ratios for both Pd(II) and Pt(II) were above 95%. The organic phase could be reused for at least 6 cycles of extraction–stripping processes. The mechanisms of extraction reaction were deduced to be ion-association mechanisms. CONCLUSION The process could be applied for extracting and separating palladium and platinum from the cyanide leaching liquor of the flotation concentrate. © 2016 Society of Chemical Industry
- Published
- 2017
27. Selective recovery of platinum by combining a novel reusable ionic liquid with electrodeposition
- Author
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Min Shao, Shunling Li, Muhan Chen, Zhangjie Huang, and Ci Jin
- Subjects
Materials science ,Precipitation (chemistry) ,Metal ions in aqueous solution ,chemistry.chemical_element ,Filtration and Separation ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Analytical Chemistry ,Metal ,chemistry.chemical_compound ,020401 chemical engineering ,chemistry ,X-ray photoelectron spectroscopy ,Bromide ,visual_art ,Ionic liquid ,visual_art.visual_art_medium ,0204 chemical engineering ,0210 nano-technology ,Platinum ,Dissolution ,Nuclear chemistry - Abstract
In this study, five new imidazolium ionic liquids (ILs) were synthesized, and their efficiencies toward the precipitation of PtCl62− in HCl media were evaluated. The prepared compounds were identified as 1-alkyl-3-propylimidazolium bromide ([CnPIm]Br, n = 12, 14, and 16), 1-tetradecyl-2-aminoethylimidazolium bromide ([C14PImNH2]Br), and 1-tetradecyl-3-butylimidazolium bromide ([C14PIm]Br). FT-IR, 1H NMR, and continuous variation method analysis were used to establish the ion-exchange model of Pt(IV) precipitation. To extract Pt(IV) from mixed metal solutions, and a novel mixed-ILs system was obtained through the dissolution of 1-tetradecyl-3-propylimidazolium bromide ([C14PIm]Br) in hydrophobic ILs ([C8MIm][PF6]). The mixed-ILs ([C14PIm]Br/[C8MIm][PF6]) exhibited excellent extraction efficiency compared to single [C8MIm][PF6]. Also, Pt(IV) ions were selectively separated from mixed metal solutions containing Rh(III), Fe3+, Ni2+, Cu2+, and Zn2+ metal ions. The separation factor βPt/M (M: Fe, Ni, Cu, Zn, or Rh) was above 105 for all systems. The optimal potentiostatic deposition voltage of Pt was estimated to −1.75 V. Direct electrodeposition from ILs containing [C14PIm]Br/[C8MIm][PF6] with Pt(IV), more than 97% of Pt(IV) was reduced to Pt(0) on the copper cathode, while the system could also be regenerated for PtCl62− extraction. Surface characterization techniques like SEM, TEM, and XPS identified the deposited silver-grey films on cathode surfaces as Pt metal with metallic luster.
- Published
- 2021
28. Removal of metal-cyanide complexes and recovery of Pt(II) and Pd(II) from wastewater using an alkali–tolerant metal-organic resin
- Author
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Shunling Li, Xiaoguang Xie, Min Shao, Muhan Chen, Zhangjie Huang, and Ci Jin
- Subjects
021110 strategic, defence & security studies ,Environmental Engineering ,Ion exchange ,Ligand ,Health, Toxicology and Mutagenesis ,Cyanide ,Inorganic chemistry ,0211 other engineering and technologies ,Ionic bonding ,02 engineering and technology ,010501 environmental sciences ,Alkali metal ,01 natural sciences ,Pollution ,Metal ,chemistry.chemical_compound ,Adsorption ,chemistry ,visual_art ,Pyridine ,visual_art.visual_art_medium ,Environmental Chemistry ,Waste Management and Disposal ,0105 earth and related environmental sciences - Abstract
Metal-cyanide complexes are hazardous and toxic pollutants that can accumulate in organisms, and their natural degradation is difficult. These complexes are primarily present in alkaline wastewater effluents, and an effective technique for their removal must be developed. Herein, we have successfully synthesized a novel quaternary ammonium-functionalized Zr4+ metal-organic resin (MOR) (H16[Zr6O16(MPATP)4]Cl8·xH2O, MPATP = 2-((1-methylpyridin-1-ium-2-ylmethyl)amino)-terephthalic acid), which we refer to as MOR-2-QAS. With alkali resistance, high surface area, and high anion exchange capacity, it acts by introducing positively charged pyridine into the organic ligand. The experimental results indicate that MOR-2-QAS becomes rapidly attached and efficiently removes Pt(CN)42−, Pd(CN)42−, Co(CN)63−, and Fe(CN)63−. Valuable metals (Pt(II) and Pd(II)) can be effectively recovered from the simulated wastewater containing four-component cyanide complexes via the two-step elution process. The recovery efficiency of Pt(II) and Pd(II) was higher than 90.0% after three adsorption-desorption cycles. The adsorption mechanism, which proceeded via ionic association (ion-exchange) and complied with the minimum surface charge density experiential principle, was confirmed using density functional theory. This study provides ideas for developing efficient and stable MORs to enable the simultaneous removal of multiple metal–cyanide complexes and recovery of valuable metals.
- Published
- 2021
29. PTEN functions by recruitment to cytoplasmic vesicles
- Author
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Wu Zheng, Ante Tocilj, Nadia Jaber, Christopher R. Faehnle, Lloyd C. Trotman, Muhan Chen, Michael S. Marks, Wei-Xing Zong, Hyejin Cho, Gyula Bencze, Leemor Joshua-Tor, Elad Elkayam, Adam Naguib, Christopher P. Pratt, and Darryl J. Pappin
- Subjects
Models, Molecular ,Endosome ,Microtubules ,Receptor tyrosine kinase ,Protein Structure, Secondary ,chemistry.chemical_compound ,Mice ,Phosphatidylinositol 3-Kinases ,Phosphatidylinositol Phosphates ,PTEN ,Animals ,Phosphatidylinositol ,Transport Vesicles ,Molecular Biology ,Protein kinase B ,C2 domain ,Binding Sites ,biology ,PTEN Phosphohydrolase ,Cell Biology ,Cell biology ,chemistry ,biology.protein ,NIH 3T3 Cells ,Signal transduction ,Binding domain ,Signal Transduction - Abstract
PTEN is proposed to function at the plasma membrane, where receptor tyrosine kinases are activated. However, the majority of PTEN is located throughout the cytoplasm. Here, we show that cytoplasmic PTEN is distributed along microtubules, tethered to vesicles via phosphatidylinositol 3-phosphate (PI(3)P), the signature lipid of endosomes. We demonstrate that the non-catalytic C2 domain of PTEN specifically binds PI(3)P through the CBR3 loop. Mutations render this loop incapable of PI(3)P binding and abrogate PTEN-mediated inhibition of PI 3-kinase/AKT signaling. This loss of function is rescued by fusion of the loop mutant PTEN to FYVE, the canonical PI(3)P binding domain, demonstrating the functional importance of targeting PTEN to endosomal membranes. Beyond revealing an upstream activation mechanism of PTEN, our data introduce the concept of PI 3-kinase signal activation on the vast plasma membrane that is contrasted by PTEN-mediated signal termination on the small, discrete surfaces of internalized vesicles.
- Published
- 2014
30. Pleckstrin homology domain leucine-rich repeat protein phosphatases set the amplitude of receptor tyrosine kinase output
- Author
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Muhan Chen, Ksenya Cohen-Katsenelson, Gloria Reyes, John Brognard, Matt Niederst, Joshua D. Stender, Maya T. Kunkel, Emma Sierecki, Tianyan Gao, Lloyd C. Trotman, Christopher K. Glass, Dawid G. Nowak, and Alexandra C. Newton
- Subjects
Repetitive Sequences, Amino Acid ,Transcription, Genetic ,MAP Kinase Signaling System ,Knockout ,Biology ,Models, Biological ,Tropomyosin receptor kinase C ,Repetitive Sequences ,Receptor tyrosine kinase ,Cell Line ,Mice ,Phosphatidylinositol 3-Kinases ,Rare Diseases ,Genetic ,Growth factor receptor ,Models ,Phosphoprotein Phosphatases ,2.1 Biological and endogenous factors ,Animals ,Aetiology ,Protein kinase B ,Protein Kinase C ,Cancer ,Cell Line, Transformed ,Mice, Knockout ,PHLPP ,Multidisciplinary ,Nuclear Proteins ,Biological ,Brain Disorders ,Rats ,ErbB Receptors ,Amino Acid ,Transformed ,PNAS Plus ,ROR1 ,Cancer research ,biology.protein ,Transcription ,Proto-Oncogene Proteins c-akt ,Tyrosine kinase ,Proto-oncogene tyrosine-protein kinase Src - Abstract
Growth factor receptor levels are aberrantly high in diverse cancers, driving the proliferation and survival of tumor cells. Understanding the molecular basis for this aberrant elevation has profound clinical implications. Here we show that the pleckstrin homology domain leucine-rich repeat protein phosphatase (PHLPP) suppresses receptor tyrosine kinase (RTK) signaling output by a previously unidentified epigenetic mechanism unrelated to its previously described function as the hydrophobic motif phosphatase for the protein kinase AKT, protein kinase C, and S6 kinase. Specifically, we show that nuclear-localized PHLPP suppresses histone phosphorylation and acetylation, in turn suppressing the transcription of diverse growth factor receptors, including the EGF receptor. These data uncover a much broader role for PHLPP in regulation of growth factor signaling beyond its direct inactivation of AKT: By suppressing RTK levels, PHLPP dampens the downstream signaling output of two major oncogenic pathways, the PI3 kinase/AKT and the Rat sarcoma (RAS)/ERK pathways. Our data are consistent with a model in which PHLPP modifies the histone code to control the transcription of RTKs.
- Published
- 2014
31. PHLPP phosphatases are master regulators of cellular receptor tyrosine kinase levels (802.19)
- Author
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John Brognard, Maya T. Kunkel, Gloria Reyes, Matt Niederst, Lloyd C. Trotman, Muhan Chen, Ksenya Cohen Katsenelson, Dawid G. Nowak, and Alexandra C. Newton
- Subjects
PHLPP ,biology ,Chemistry ,Protein tyrosine phosphatase ,Biochemistry ,Tropomyosin receptor kinase C ,Receptor tyrosine kinase ,Cell biology ,Growth factor receptor ,ROR1 ,Genetics ,biology.protein ,Molecular Biology ,Protein kinase B ,Tyrosine kinase ,Biotechnology - Abstract
Growth factor receptor levels are aberrantly high in diverse cancers, driving the proliferation and survival of tumor cells. Understanding the molecular basis for this aberrant elevation has profound clinical applications. Here we show that the PH domain leucine-rich repeat protein phosphatase (PHLPP) suppresses the steady-state levels of receptor tyrosine kinases (RTKs) by a novel mechanism unrelated to its previously described function as the hydrophobic motif phosphatase for AKT, protein kinase C and S6 kinase. Specifically, genetic depletion and pharmacological studies reveal that PHLPP1 and PHLPP2 promote histone deacetylase (HDAC)-dependent repression of the transcription of diverse growth factor receptors, including the EGF receptor. These data uncover a novel, and much broader, role for PHLPP in regulation of growth factor signaling beyond its direct inactivation of AKT: by suppressing RTK levels, PHLPP dampens the downstream signaling output of two major oncogenic pathways, the PI3 kinase/AKT and...
- Published
- 2014
32. Application of transgenic mice models in functional study of two putative oncogenes : ALC-1 and EIF5A2
- Author
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Muhan. Chen
- Subjects
Genetically modified mouse ,Computational biology ,Biology ,Bioinformatics - Published
- 2012
33. Identification of PHLPP1 as a tumor suppressor reveals the role of feedback activation in PTEN-mutant prostate cancer progression
- Author
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Martha E. Zeeman, Nikolaus Schultz, Adam Naguib, Jernej Murn, Chris Sander, William L. Gerald, Gurinder S. Atwal, Nicholas Navin, Barry S. Taylor, Carlos Cordon-Cardo, Lloyd C. Trotman, Brett S. Carver, Dawid G. Nowak, Alexandra C. Newton, Audrey K. O’Neill, Mireia Castillo-Martin, Christopher P. Pratt, Danielle M. Grace, and Muhan Chen
- Subjects
Male ,Cancer Research ,medicine.disease_cause ,Article ,law.invention ,03 medical and health sciences ,Prostate cancer ,0302 clinical medicine ,law ,Prostate ,medicine ,Phosphoprotein Phosphatases ,PTEN ,Humans ,PI3K/AKT/mTOR pathway ,030304 developmental biology ,0303 health sciences ,PHLPP ,Mutation ,biology ,PTEN Phosphohydrolase ,Nuclear Proteins ,Prostatic Neoplasms ,Cell Biology ,Chromoplexy ,medicine.disease ,3. Good health ,medicine.anatomical_structure ,Oncology ,030220 oncology & carcinogenesis ,Cancer research ,biology.protein ,Disease Progression ,Suppressor - Abstract
SummaryHyperactivation of the PI 3-kinase/AKT pathway is a driving force of many cancers. Here we identify the AKT-inactivating phosphatase PHLPP1 as a prostate tumor suppressor. We show that Phlpp1-loss causes neoplasia and, on partial Pten-loss, carcinoma in mouse prostate. This genetic setting initially triggers a growth suppressive response via p53 and the Phlpp2 ortholog, and reveals spontaneous Trp53 inactivation as a condition for full-blown disease. Surprisingly, the codeletion of PTEN and PHLPP1 in patient samples is highly restricted to metastatic disease and tightly correlated to deletion of TP53 and PHLPP2. These data establish a conceptual framework for progression of PTEN mutant prostate cancer to life-threatening disease.
- Published
- 2011
34. Isolation and characterization of a novel oncogene, amplified in liver cancer 1, within a commonly amplified region at 1q21 in hepatocellular carcinoma
- Author
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Leilei Chen, Muhan Chen, Liang Hu, Yan Fang, Ning-Fang Ma, Bo-Jian Zheng, Jackie M.W. Fung, Li Fu, Xin Yuan Guan, Dan Xie, D Tang, and Zhenguo Wu
- Subjects
Oncogene Proteins ,Small interfering RNA ,Carcinoma, Hepatocellular ,Hepatology ,Oncogene ,Liver Neoplasms ,Gene Amplification ,Cancer ,Oncogenes ,Biology ,Amplicon ,medicine.disease ,Virology ,CHD1L ,Gene Expression Regulation, Neoplastic ,Chromosomes, Human, Pair 1 ,Hepatocellular carcinoma ,Cell Line, Tumor ,medicine ,Cancer research ,Humans ,Gene Silencing ,Liver cancer ,In Situ Hybridization, Fluorescence - Abstract
Amplification of 1q21 is the most frequent genetic alteration in human hepatocellular carcinoma (HCC), being detected in 58%-78% of primary HCC cases by comparative genomic hybridization. Recently, we isolated a candidate oncogene, Amplified in Liver Cancer 1 (ALC1), from 1q21 by hybrid selection. Here we demonstrate that ALC1 was frequently amplified and overexpressed in HCC. ALC1-transfected cells possessed a strong oncogenic ability, increasing the colony formation in soft agar and increasing the tumorigenicity in nude mice, which could be effectively suppressed by small interfering RNA against ALC1. Functional studies showed that overexpression of ALC1 could promote G1/S phase transition and inhibit apoptosis. Molecular studies revealed that the oncogenic function of ALC1 might be associated with its roles in promoting cell proliferation by down-regulating p53 expression. Conclusion: These results suggest that ALC1 is the target oncogene within the 1q21 amplicon and plays a pivotal role in HCC pathogenesis. (HEPATOLOGY 2007.)
- Published
- 2007
35. Abstract LB-063: PTEN function is controlled by recruitment to cytoplasmic vesicles
- Author
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Leemor Joshua-Tor, Nadia Jaber, Wu Zheng, Christopher R. Faehnle, Christopher P. Pratt, Elad Elkayam, Hyejin Cho, Gylua Bencze, Muhan Chen, Adam Naguib, Michael S. Marks, Ante Tocilj, Wei-Xing Zong, Darryl J. Pappin, and Lloyd C. Trotman
- Subjects
Cancer Research ,Oncology ,biology ,Chemistry ,biology.protein ,PTEN ,Function (biology) ,Cytoplasmic vesicle ,Cell biology - Abstract
PTEN is thought to function at the plasma membrane where receptor tyrosine kinases activate PI 3-Kinases. Yet the majority of PTEN is located throughout the cytoplasm so that only a fraction of PTEN could be actively suppressing PI 3-K signaling at any time. Here we show that cytoplasmic PTEN is distributed along microtubules, tethered to vesicles via interaction with phosphatidylinositol 3- phosphate (PI(3)P), the signature lipid of endosomes. We demonstrate that the C2 domain of PTEN specifically binds PI(3)P via the CBR3-loop. Mutations that render the CBR3-loop incapable of PI(3)P binding abrogate PTEN function in cells but not in vitro. The loss-of-function in cells is rescued by fusion of the canonical PI(3)P vesicle targeting domain, FYVE, to CBR3-loop mutant PTEN, demonstrating the functional relevance of PTEN activity on endosomal membranes. These findings introduce an entirely unexpected site of action of the PTEN tumor suppressor. Furthermore, they introduce the concept of PI 3-K signal activation over the vast surface of the plasma membrane that is contrasted by PTEN-mediated signal termination on the discretely sized and much smaller surfaces of endocytic vesicles. Implications of these results for cancer signaling and growth control will be discussed. Note: This abstract was not presented at the meeting. Citation Format: Adam Naguib, Gylua Bencze, Hyejin Cho, Wu Zheng, Ante Tocilj, Elad Elkayam, Christopher R Faehnle, Nadia Jaber, Christopher Pratt, Muhan Chen, Wei-Xing Zong, Michael S Marks, Leemor Joshua-Tor, Darryl J Pappin, Lloyd C. Trotman. PTEN function is controlled by recruitment to cytoplasmic vesicles. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-063. doi:10.1158/1538-7445.AM2015-LB-063
- Published
- 2015
36. Abstract 2258: Myc drives Pten/ p53-deficient proliferation and metastasis due to Il6-secretion and Akt-suppression via Phlpp2
- Author
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David Kleinman, Lloyd C. Trotman, Serif Senturk, Christof Fellmann, Brian D. Robinson, Victoria M.-Y. Wang, Dawid G. Nowak, Mireia Castillo-Martin, Hyejin Cho, Kaitlin Watrud, Tali Herzka, Muhan Chen, David Ding, Carlos Cordon-Cardo, John E. Wilkinson, Tumas Beinortas, and Daniel V. DeMarco
- Subjects
Cancer Research ,Cell growth ,medicine.medical_treatment ,Phosphatase ,Cancer ,Biology ,medicine.disease ,Metastasis ,Cytokine ,Oncology ,medicine ,Cancer research ,biology.protein ,PTEN ,STAT3 ,Protein kinase B - Abstract
The sporadic transition from indolent to metastatic disease is a hallmark of prostate cancer (PC) and frequently involves deletion of PTEN and TP53. We recently recapitulated metastasis of Pten/ Trp53-mutant PC in mouse using the RapidCaP system and surprisingly, we found that it is driven by Myc, rather than Akt activation. Here, we show that cell-cell communication by Il6 drives this Akt-Myc switch through activation of the Akt-inactivating phosphatase Phlpp2. Primary cells revealed that loss of Pten/ Trp53 triggers secretion of the Il6 cytokine when these genes are deleted together, but not separately. Il6 then communicates a downstream program of Stat3-mediated Myc activation, which drives cell proliferation. Abrogation of Myc activity by Myc inhibition with the JQ1 bromodomain inhibitor, Myc-RNAi, and Myc-CRISPR/ Cas9 approaches inhibited proliferation. We validated these findings in vivo, where peak proliferation in Pten/ Trp53 mutant primary and metastatic PC did not correlate with activated Akt, but with Stat3/ Myc activation instead. Most notably, we found that Myc strongly activates the Akt phosphatase Phlpp2 in primary cells and RapidCaP metastasis, and showed genetically that Phlpp2 is essential for dictating proliferation and Myc-mediated suppression of Akt. Collectively, our data reveal competition between two proto-oncogenes: Myc and Akt, which ensnarls the Phlpp2 gene to facilitate Myc-driven metastasis. Citation Format: Dawid G. Nowak, Hyejin Cho, Tali Herzka, Victoria M.Y. Wang, Serif Senturk, Daniel V. DeMarco, David Ding, Christof Fellmann, Tumas Beinortas, David Kleinman, Kaitlin Watrud, Muhan Chen, John E. Wilkinson, Mireia Castillo-Martin, Carlos Cordon-Cardo, Brian D. Robinson, Lloyd C. Trotman. Myc drives Pten/ p53-deficient proliferation and metastasis due to Il6-secretion and Akt-suppression via Phlpp2. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2258. doi:10.1158/1538-7445.AM2015-2258
- Published
- 2015
37. High-throughput loss-of-heterozygosity study of chromosome 3p in lung cancer using single-nucleotide polymorphism markers
- Author
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You-Qiang Song, Yan Fang, Pak C. Sham, Xin Yuan Guan, Muhan Chen, William Mak, Daniel T.T. Chua, Kevin K. W. Chu, Phoebe K.M. Ng, Mandy Y.M. Ng, Amy L.S. Tai, Li Fu, and Minyue Zhang
- Subjects
Genetics ,Cancer Research ,Lung Neoplasms ,Genotype ,Cancer ,Chromosome ,Loss of Heterozygosity ,Nucleic Acid Hybridization ,Reproducibility of Results ,Single-nucleotide polymorphism ,Biology ,medicine.disease ,Polymorphism, Single Nucleotide ,Loss of heterozygosity ,Oncology ,Chromosome 3 ,Polymorphism (computer science) ,Carcinoma, Non-Small-Cell Lung ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,medicine ,SNP ,Humans ,Genes, Tumor Suppressor ,Chromosomes, Human, Pair 3 - Abstract
Loss of DNA copy number at the short arm of chromosome 3 is one of the most common genetic changes in human lung cancer, suggesting the existence of one or more tumor suppressor genes (TSG) at 3p. To identify most frequently deleted regions and candidate TSGs within these regions, a recently developed single-nucleotide polymorphism (SNP)-mass spectrometry-genotyping (SMSG) technology was applied to investigate the loss of heterozygosity (LOH) in 30 primary non–small-cell lung cancers. A total of 386 SNP markers that spanned a region of 70 Mb at 3p, from 3pter to 3p14.1, were selected for LOH analysis. The average intermarker distance in the present study is ∼180 kb. Several frequently deleted regions, including 3p26.3, 3p25.3, 3p24.1, 3p23, and 3p21.1, were found. Several candidate TSGs within these frequently detected LOH regions have been found, including APG7L at 3p25.3, CLASP2 at 3p23, and CACNA2D3 at 3p21.1. This study also showed that SMSG technology is a very useful approach to rapidly define the minimal deleted region and to identify target TSGs in a given cancer. (Cancer Res 2006; 66(8): 4133-8)
- Published
- 2006
38. Abstract 5258: PTEN levels are controlled by a nuclear transport receptor in lung cancer
- Author
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Scott M. Plafker, Lloyd C. Trotman, Mireia Castillo-Martin, Kendra S. Plafker, Muhan Chen, Carlos Cordon-Cardo, Matthias Minderer, Tali Herzka, and Martha E. Zeeman
- Subjects
Cancer Research ,biology ,Importin ,medicine.disease ,law.invention ,Oncology ,Ubiquitin ,law ,biology.protein ,medicine ,Cancer research ,Suppressor ,Adenocarcinoma ,PTEN ,Nuclear transport ,Receptor ,Lung cancer - Abstract
The maintenance of PTEN protein levels is critical for tumor suppression. Yet, the ubiquitination system has been shown to affect PTEN levels both adversely through degradation, as well as positively through nuclear import, and it has remained unclear how these two processes are integrated to prevent cancer. Here we show, that a nuclear import receptor is at the heart of a failsafe system that maintains PTEN levels by mediating its nuclear transport. Loss of import receptor function not only leads to cytoplasmic PTEN accumulation but also prompts PTEN degradation through a novel component of the PTEN ubiquitination system. By testing the consequences of importin loss in vivo, we found that hypomorphic mice developed lung adenocarcinoma, which presented with aberrant cytoplasmic PTEN localization and degradation, as predicted by our in vitro findings. Since the corresponding human locus suffers frequent deletion as well as inactivating mutations in lung cancer, we propose that this import receptor is a novel tumor suppressor that antagonizes PI 3-Kinase signaling in settings with at least one intact PTEN gene. Citation Format: Muhan Chen, Tali M. Herzka, Martha E. Zeeman, Kendra S. Plafker, Matthias Minderer, Mireia Castillo-Martin, Carlos Cordon-Cardo, Scott M. Plafker, Lloyd C. Trotman. PTEN levels are controlled by a nuclear transport receptor in lung cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5258. doi:10.1158/1538-7445.AM2013-5258
- Published
- 2013
39. Abstract 2405: Identification of PHLPP as a tumour suppressor reveals the role of pathway feedback compensation in PTEN-mutant prostate cancer progression
- Author
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Mireia Castillo-Martin, Adam Naguib, N. Schultz, Martha E. Zeeman, William L. Gerald, Lloyd C. Trotman, Barry S. Taylor, Brett S. Carver, Chris Sander, Muhan Chen, Dawid G. Nowak, Alexandra C. Newton, Audrey K. O’Neill, Christopher P. Pratt, Jernej Murn, Danielle M. Grace, and Carlos Cordon-Cardo
- Subjects
Senescence ,Oncology ,Cancer Research ,medicine.medical_specialty ,PHLPP ,Cancer ,Biology ,medicine.disease ,law.invention ,Prostate cancer ,medicine.anatomical_structure ,Prostate ,law ,Internal medicine ,medicine ,biology.protein ,Suppressor ,PTEN ,PI3K/AKT/mTOR pathway - Abstract
Hyper-activation of the PI 3-Kinase/ AKT pathway is common in many cancer types. Tumourigenesis through this pathway is prevented by concerted action of multiple tumour suppressor genes. Most notably, PTEN reverts PI 3-Kinase activity whereas excessive pathway activation triggers the p53-mediated senescence arrest. However, it remains ill defined if and at what stage this response acts in human prostate cancer. Here we identify the AKT-inactivating phosphatase PHLPP as a tumour suppressor and demonstrate how the p53-response can antagonise co-deletion of PTEN and PHLPP to form a barrier against prostate cancer progression. We show that Phlpp-loss causes neoplasia and upon partial Pten-loss, carcinoma in mouse prostate. In this setting, Phlpp-deficiency triggers growth arrest via mTorC1-dependent activation of p53 and we find that co-deletion of Pten and Phlpp selects for spontaneous inactivation of p53 in prostate. Validating this conditional gene inactivation scheme in a comprehensive genomic patient data set we find that co-deletion of PTEN and PHLPP is almost exclusively observed in metastatic prostate cancer and tightly correlated to deletion of TP53. Furthermore, PTEN/ PHLPP expression can be used to predict disease outcome in these patients, comparable to the standard histology based method, but adding actionable information on pathway status. Finally, we show that both known PHLPP isoforms compensate for PTEN-suppression in a novel pathway feedback explaining their co-deletion with PTEN in the metastatic samples. Surprisingly, we find that the feedback surge of these genes is sensitive to some pharmacological inhibitors of the PI 3-Kinase pathway. Collectively, our findings emphasise the need for careful evaluation of PI 3-Kinase target therapy effects in prostate cancer and highlight the value of genetically engineered mouse models in this process. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2405. doi:10.1158/1538-7445.AM2011-2405
- Published
- 2011
40. Abstract 1269: Identifying Pten-sensitive drug therapy through metabolic phenotype-arrays
- Author
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Lloyd C. Trotman, Dawid G. Nowak, Adam Naguib, and Muhan Chen
- Subjects
Cancer Research ,Mutation ,Chemotherapy ,medicine.medical_treatment ,Cancer ,Biology ,medicine.disease_cause ,medicine.disease ,Phenotype ,law.invention ,Prostate cancer ,medicine.anatomical_structure ,Oncology ,Prostate ,law ,Immunology ,medicine ,Cancer research ,biology.protein ,Suppressor ,PTEN - Abstract
The loss or mutation of tumor suppressor genes is a predominant event in the initiation, progression and metastatic development of cancer. PTEN and p53 are frequently inactivated in lethal metastatic prostate cancer, as they provide a critical growth, proliferation and anti-apoptotic advantage to cells in which their activity is diminished. In mouse prostate cancer models, loss of p53 alone in the prostate does not result in noticeable neoplasia. However, subsequent additional deletion of Pten causes lethal prostatic adenocarcinoma within 6 months, illustrating the need to combat the cooperative power of these two genetic lesions. Although inactivation of these tumor suppressor genes has been widely described at the level of their cancer phenotype, it has recently emerged that one understudied route to combat lesions harboring these alterations is to understand and exploit critical underlying changes in their metabolic makeup. In the present study, we used an array platform to determine the growth phenotype of p53 null Mouse Embryonic Fibroblast (MEFs) under close to 1200 conditions involving different sources of energy, amino acids, hormones, growth factors, chemical ions and responses to chemotherapy agents. with subsequent comparison to the response in p53/Pten double-null MEFs. Our analysis showed that loss of Pten critically altered response, utilization and sensitivity especially to specific hormones, ions and chemotherapy agents. Since this approach revealed Pten-status specific cell sensitivities, we are utilizing this information to establish selective targeting of cells as a precursor to therapeutic intervention in our genetically engineered mouse models of prostate cancer, which harbor the identical tumor suppressor lesions. Collectively, our results establish a rapid screening platform for identification of genotype-specific anti-cancer agents. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1269. doi:10.1158/1538-7445.AM2011-1269
- Published
- 2011
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