91 results on '"Y. Y. Sun"'
Search Results
2. Signatures of magnetism control by flow of angular momentum.
- Author
-
Chen L, Sun Y, Mankovsky S, Meier TNG, Kronseder M, Sun C, Orekhov A, Ebert H, Weiss D, and Back CH
- Abstract
Exploring new strategies to manipulate the order parameter of magnetic materials by electrical means is of great importance not only for advancing our understanding of fundamental magnetism but also for unlocking potential applications. A well-established concept uses gate voltages to control magnetic properties by modulating the carrier population in a capacitor structure
1-5 . Here we show that, in Pt/Al/Fe/GaAs(001) multilayers, the application of an in-plane charge current in Pt leads to a shift in the ferromagnetic resonance field depending on the microwave frequency when the Fe film is sufficiently thin. The experimental observation is interpreted as a current-induced modification of the magnetocrystalline anisotropy ΔHA of Fe. We show that (1) ΔHA decreases with increasing Fe film thickness and is connected to the damping-like torque; and (2) ΔHA depends not only on the polarity of charge current but also on the magnetization direction, that is, ΔHA has an opposite sign when the magnetization direction is reversed. The symmetry of the modification is consistent with a current-induced spin6-8 and/or orbit9-13 accumulation, which, respectively, act on the spin and/or orbit component of the magnetization. In this study, as Pt is regarded as a typical spin current source6,14 , the spin current can play a dominant part. The control of magnetism by a spin current results from the modified exchange splitting of the majority and minority spin bands, providing functionality that was previously unknown and could be useful in advanced spintronic devices., (© 2024. The Author(s).)- Published
- 2024
- Full Text
- View/download PDF
3. Quasi-quantized Hall response in bulk InAs.
- Author
-
Wawrzyńczak R, Galeski S, Noky J, Sun Y, Felser C, and Gooth J
- Abstract
The quasi-quantized Hall effect (QQHE) is the three-dimensional (3D) counterpart of the integer quantum Hall effect (QHE), exhibited only by two-dimensional (2D) electron systems. It has recently been observed in layered materials, consisting of stacks of weakly coupled 2D platelets that are yet characterized by a 3D anisotropic Fermi surface. However, it is predicted that the quasi-quantized 3D version of the 2D QHE should occur in a much broader class of bulk materials, regardless of the underlying crystal structure. Here, we compare the observation of quasi-quantized plateau-like features in the Hall conductivity of the n-type bulk semiconductor InAs with the predictions for the 3D QQHE in presence of parabolic electron bands. InAs takes form of a cubic crystal without any low-dimensional substructure. The onset of the plateau-like feature in the Hall conductivity scales with [Formula: see text] in units of the conductance quantum and is accompanied by a Shubnikov-de Haas minimum in the longitudinal resistivity, consistent wit the results of calculations. This confirms the suggestion that the 3D QQHE may be a generic effect directly observable in materials with small Fermi surfaces, placed in sufficiently strong magnetic fields., (© 2022. The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
4. Author Correction: Axionic charge-density wave in the Weyl semimetal (TaSe 4 ) 2 I.
- Author
-
Gooth J, Bradlyn B, Honnali S, Schindler C, Kumar N, Noky J, Qi Y, Shekhar C, Sun Y, Wang Z, Bernevig BA, and Felser C
- Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
- Published
- 2020
- Full Text
- View/download PDF
5. Axionic charge-density wave in the Weyl semimetal (TaSe 4 ) 2 I.
- Author
-
Gooth J, Bradlyn B, Honnali S, Schindler C, Kumar N, Noky J, Qi Y, Shekhar C, Sun Y, Wang Z, Bernevig BA, and Felser C
- Abstract
An axion insulator is a correlated topological phase, which is predicted to arise from the formation of a charge-density wave in a Weyl semimetal
1,2 -that is, a material in which electrons behave as massless chiral fermions. The accompanying sliding mode in the charge-density-wave phase-the phason-is an axion3,4 and is expected to cause anomalous magnetoelectric transport effects. However, this axionic charge-density wave has not yet been experimentally detected. Here we report the observation of a large positive contribution to the magnetoconductance in the sliding mode of the charge-density-wave Weyl semimetal (TaSe4 )2 I for collinear electric and magnetic fields. The positive contribution to the magnetoconductance originates from the anomalous axionic contribution of the chiral anomaly to the phason current, and is locked to the parallel alignment of the electric and magnetic fields. By rotating the magnetic field, we show that the angular dependence of the magnetoconductance is consistent with the anomalous transport of an axionic charge-density wave. Our results show that it is possible to find experimental evidence for axions in strongly correlated topological condensed matter systems, which have so far been elusive in any other context.- Published
- 2019
- Full Text
- View/download PDF
6. Observation of η-Al 41 Sm 5 reveals motif-aware structural evolution in Al-Sm alloys.
- Author
-
Ye Z, Meng F, Zhang F, Sun Y, Yang L, Zhou SH, Napolitano RE, Mendelev MI, Ott RT, Kramer MJ, Wang CZ, and Ho KM
- Abstract
Using an effective genetic algorithm, we uncover the structure of a metastable Al
41 Sm5 phase that supplements its family sharing similar short-range orders. The phase evolves upon heating an amorphous Al-9.7 at.% Sm ribbon, produced by melt-spinning. The dynamical phase selection is discussed with respect to the structural connections between the short-range packing motifs in the amorphous precursor and those observed in the selected phases. The phase elucidated here is one of several newly discovered large-unit-cell phases found to form during devitrification from the glass in this binary system, further illustrating the power and efficiency of our approach, the important role of structural hierarchy in phase selection, and the richness of the metastable phase landscape accessible from the glassy structure.- Published
- 2019
- Full Text
- View/download PDF
7. The association between subclass-specific IgG Fc N-glycosylation profiles and hypertension in the Uygur, Kazak, Kirgiz, and Tajik populations.
- Author
-
Liu JN, Dolikun M, Štambuk J, Trbojević-Akmačić I, Zhang J, Wang H, Zheng DQ, Zhang XY, Peng HL, Zhao ZY, Liu D, Sun Y, Sun Q, Li QH, Zhang JX, Sun M, Cao WJ, Momčilović A, Razdorov G, Wu LJ, Russell A, Wang YX, Song MS, Lauc G, and Wang W
- Subjects
- Adult, Aged, Asia, Central ethnology, Biomarkers blood, Case-Control Studies, China epidemiology, Female, Glycosylation, Humans, Hypertension ethnology, Male, Middle Aged, Hypertension immunology, Immunoglobulin G metabolism
- Abstract
Hypertension results from the interaction of genetic and acquired factors. IgG occurs in the form of different subclasses, of which the effector functions show significant variation. The detailed differences between the glycosylation profiles of the individual IgG subclasses may be lost in a profiling method for total IgG N-glycosylation. In this study, subclass-specific IgG Fc glycosylation profile was investigated in the four northwestern Chinese minority populations, namely, Uygur (UIG), Kazak (KZK), Kirgiz (KGZ), and Tajik (TJK), composed of 274 hypertensive patients and 356 healthy controls. The results showed that ten directly measured IgG N-glycan traits (i.e., IgG1G0F, IgG2G0F, IgG2G1FN, IgG2G1FS, IgG2G2S, IgG4G0F, IgG4G1FS, IgG4G1S, IgG4G2FS, and IgG4G2N) representing galactosylation and sialylation are significantly associated with hypertension, with IgG4 consistently showing weaker associations of its sialylation, across the four ethnic groups. We observed a modest improvement on the AUC of ROC curve when the IgG Fc N-glycan traits are added into the glycan-based model (difference between AUCs, 0.044, 95% CI: 0.016-0.072, P = 0.002). The AUC of the diagnostic model indicated that the subclass-specific IgG Fc N-glycan profiles provide more information reinforcing current models utilizing age, gender, BMI, and ethnicity, and demonstrate the potential of subclass-specific IgG Fc N-glycosylation profiles to serve as a biomarker for hypertension. Further research is however required to determine the additive value of subclass-specific IgG Fc N-glycosylation on top of biomarkers, which are currently used.
- Published
- 2018
- Full Text
- View/download PDF
8. Optical properties of dense lithium in electride phases by first-principles calculations.
- Author
-
Yu Z, Geng HY, Sun Y, and Chen Y
- Abstract
The metal-semiconductor-metal transition in dense lithium is considered as an archetype of interplay between interstitial electron localization and delocalization induced by compression, which leads to exotic electride phases. In this work, the dynamic dielectric response and optical properties of the high-pressure electride phases of cI16, oC40 and oC24 in lithium spanning a wide pressure range from 40 to 200 GPa by first-principles calculations are reported. Both interband and intraband contribution to the dielectric function are deliberately treated with the linear response theory. One intraband and two interband plasmons in cI16 at 70 GPa induced by a structural distortion at 2.1, 4.1, and 7.7 eV are discovered, which make the reflectivity of this weak metallic phase abnormally lower than the insulating phase oC40 at the corresponding frequencies. More strikingly, oC24 as a reentrant metallic phase with higher conductivity becomes more transparent than oC40 in infrared and visible light range due to its unique electronic structure around Fermi surface. An intriguing reflectivity anisotropy in both oC40 and oC24 is predicted, with the former being strong enough for experimental detection within the spectrum up to 10 eV. The important role of interstitial localized electrons is highlighted, revealing diversity and rich physics in electrides.
- Published
- 2018
- Full Text
- View/download PDF
9. Identification of translationally controlled tumor protein in promotion of DNA homologous recombination repair in cancer cells by affinity proteomics.
- Author
-
Li Y, Sun H, Zhang C, Liu J, Zhang H, Fan F, Everley RA, Ning X, Sun Y, Hu J, Liu J, Zhang J, Ye W, Qiu X, Dai S, Liu B, Xu H, Fu S, Gygi SP, and Zhou C
- Subjects
- Apoptosis drug effects, DNA Breaks, Double-Stranded, HeLa Cells, Humans, MCF-7 Cells, Neoplasm Proteins genetics, Neoplasms drug therapy, Sertraline pharmacology, Tumor Protein, Translationally-Controlled 1, Neoplasm Proteins physiology, Neoplasms genetics, Protein Biosynthesis, Proteomics methods, Recombinational DNA Repair
- Abstract
Translationally controlled tumor protein(TCTP) has been implicated in the regulation of apoptosis, DNA repair and drug resistance. However, the underlying molecular mechanisms are poorly defined. To better understand the molecular mechanisms underlying TCTP involved in cellular processes, we performed an affinity purification-based proteomic profiling to identify proteins interacting with TCTP in human cervical cancer HeLa cells. We found that a group of proteins involved in DNA repair are enriched in the potential TCTP interactome. Silencing TCTP by short hairpin RNA in breast carcinoma MCF-7 cells leads to the declined repair efficiency for DNA double-strand breaks on the GFP-Pem1 reporter gene by homologous recombination, the persistent activation and the prolonged retention of γH2AX and Rad51 foci following ionizing radiation. Reciprocal immunoprecipitations indicated that TCTP forms complexes with Rad51 in vivo, and the stability maintenance of Rad51 requires TCTP in MCF-7 cells under normal cell culture conditions. Moreover, inactivation of TCTP by sertraline treatment enhances UVC irradiation-induced apoptosis in MCF-7 cells, and causes sensitization to DNA-damaging drug etoposide and DNA repair inhibitor olaparib. Thus, we have identified an important role of TCTP in promoting DNA double-stand break repair via facilitating DNA homologous recombination processes and highlighted the great potential of TCTP as a drug target to enhance conventional chemotherapy for cancer patients with high levels of TCTP expression.
- Published
- 2017
- Full Text
- View/download PDF
10. Suppression of Sirt1 sensitizes lung cancer cells to WEE1 inhibitor MK-1775-induced DNA damage and apoptosis.
- Author
-
Chen G, Zhang B, Xu H, Sun Y, Shi Y, Luo Y, Jia H, and Wang F
- Subjects
- Animals, Apoptosis drug effects, Carbazoles pharmacology, Cells, Cultured, Female, Humans, Lung Neoplasms genetics, Lung Neoplasms pathology, Mice, Mice, Inbred BALB C, Pyrazoles therapeutic use, Pyrimidines therapeutic use, Pyrimidinones, Sirtuin 1 antagonists & inhibitors, Cell Cycle Proteins antagonists & inhibitors, DNA Damage drug effects, Lung Neoplasms drug therapy, Nuclear Proteins antagonists & inhibitors, Protein-Tyrosine Kinases antagonists & inhibitors, Pyrazoles pharmacology, Pyrimidines pharmacology, Sirtuin 1 physiology
- Abstract
Lung cancer treatment remains a challenge for clinical practice and new therapeutic approaches are urgently needed. Loss of functional WEE1 kinase causes DNA replication stress, DNA damage and unscheduled mitotic entry due to elevated CDK activity. The selective WEE1 inhibitor MK-1775 synergize with DNA-damaging agent to inhibit cancer cell growth. Here we report that inhibition of Sirt1 deacetylase through small interfering RNA or selective inhibitor Ex527 greatly enhances MK-1775-induced growth inhibition and apoptosis in human lung cancer cells. We further demonstrate that Sirt1 interacts and deacetylates homologous recombination (HR) repair machinery proteins, including NBS1 and Rad51. Inhibition of Sirt1 impairs HR repair activity, which causes unrepairable damage when combining MK-1775 and Ex527. Meanwhile, combination of MK-1775 and Ex527 induces cooperative antitumor activity in lung cancer xenograft model in vivo. Thus, our study provides a novel therapeutic strategy to optimize MK-1775 treatment efficiency in lung cancers.
- Published
- 2017
- Full Text
- View/download PDF
11. SmgGDS is a transient nucleolar protein that protects cells from nucleolar stress and promotes the cell cycle by regulating DREAM complex gene expression.
- Author
-
Gonyo P, Bergom C, Brandt AC, Tsaih SW, Sun Y, Bigley TM, Lorimer EL, Terhune SS, Rui H, Flister MJ, Long RM, and Williams CL
- Subjects
- Carcinogenesis, Cell Cycle, Cell Line, Tumor, Humans, Cell Nucleolus metabolism, Cytoprotection, Gene Expression Regulation, Guanine Nucleotide Exchange Factors physiology, Kv Channel-Interacting Proteins genetics, Repressor Proteins genetics
- Abstract
The chaperone protein and guanine nucleotide exchange factor SmgGDS (RAP1GDS1) is a key promoter of cancer cell proliferation and tumorigenesis. SmgGDS undergoes nucleocytoplasmic shuttling, suggesting that it has both cytoplasmic and nuclear functions that promote cancer. Previous studies indicate that SmgGDS binds cytoplasmic small GTPases and promotes their trafficking to the plasma membrane. In contrast, little is known about the functions of SmgGDS in the nucleus, or how these nuclear functions might benefit cancer cells. Here we show unique nuclear localization and regulation of gene transcription pathways by SmgGDS. Strikingly, SmgGDS depletion significantly reduces expression of over 600 gene products that are targets of the DREAM complex, which is a transcription factor complex that regulates expression of proteins controlling the cell cycle. The cell cycle regulators E2F1, MYC, MYBL2 (B-Myb) and FOXM1 are among the DREAM targets that are diminished by SmgGDS depletion. E2F1 is well known to promote G1 cell cycle progression, and the loss of E2F1 in SmgGDS-depleted cells provides an explanation for previous reports that SmgGDS depletion characteristically causes a G1 cell cycle arrest. We show that SmgGDS localizes in nucleoli, and that RNAi-mediated depletion of SmgGDS in cancer cells disrupts nucleolar morphology, signifying nucleolar stress. We show that nucleolar SmgGDS interacts with the RNA polymerase I transcription factor upstream binding factor (UBF). The RNAi-mediated depletion of UBF diminishes nucleolar localization of SmgGDS and promotes proteasome-mediated degradation of SmgGDS, indicating that nucleolar sequestration of SmgGDS by UBF stabilizes SmgGDS protein. The ability of SmgGDS to interact with UBF and localize in the nucleolus is diminished by expressing DiRas1 or DiRas2, which are small GTPases that bind SmgGDS and act as tumor suppressors. Taken together, our results support a novel nuclear role for SmgGDS in protecting malignant cells from nucleolar stress, thus promoting cell cycle progression and tumorigenesis.
- Published
- 2017
- Full Text
- View/download PDF
12. The long noncoding RNA SNHG1 promotes tumor growth through regulating transcription of both local and distal genes.
- Author
-
Sun Y, Wei G, Luo H, Wu W, Skogerbø G, Luo J, and Chen R
- Subjects
- A549 Cells, Animals, Cell Line, Tumor, HCT116 Cells, Humans, K562 Cells, MCF-7 Cells, Male, Mice, Inbred BALB C, Mice, Nude, Transplantation, Heterologous, Carcinogenesis genetics, Cell Proliferation genetics, Gene Expression Regulation, Neoplastic, RNA, Long Noncoding genetics
- Abstract
Increasing evidence indicates that long noncoding RNAs (lncRNAs) have important roles in various physiological processes and dysfunction of lncRNAs could be a prevalent cause in human diseases. Here we functionally characterized the nuclear-enriched lncRNA SNHG1, which is highly expressed in multiple types of cancer. We also provide evidence that SNHG1 promotes cancer cell growth by regulating gene expression both in cis and in trans. SNHG1 was involved in the AKT signaling pathway as it promotes the neighboring transcription of the protein-coding gene SLC3A2 in cis by binding the Mediator complex to facilitate the establishment of enhancer-promoter interaction. In trans, SNHG1 directly interacted with central domain of FUBP1 and antagonize the binding of FBP-interacting repressor to FUBP1, thereby coordinating the expression of the oncogene MYC. Collectively, our findings demonstrate that lncRNA SNHG1 can function both in cis and in trans with distinct mechanisms to regulate transcription, promoting tumorigenesis and cancer progression.
- Published
- 2017
- Full Text
- View/download PDF
13. Smurf1 regulates lung cancer cell growth and migration through interaction with and ubiquitination of PIPKIγ.
- Author
-
Li H, Xiao N, Wang Y, Wang R, Chen Y, Pan W, Liu D, Li S, Sun J, Zhang K, Sun Y, and Ge X
- Subjects
- Cell Line, Tumor, Cell Movement genetics, Cell Proliferation genetics, Humans, Lung Neoplasms pathology, Phosphorylation, Signal Transduction, Ubiquitination genetics, Carcinogenesis genetics, Lung Neoplasms genetics, Phosphotransferases (Alcohol Group Acceptor) genetics, Ubiquitin-Protein Ligases genetics
- Abstract
Type Iγ phosphatidylinositol phosphate kinase (PIPKIγ), a phospholipid kinase generating PIP2, is positively expressed in breast cancer tissues, which correlates intimately with the progression of patients. However, little is known about the expression level of PIPKIγ in patients with other cancer types as well as their underlying regulation mechanisms. Here, we report that PIPKIγ is highly expressed in lung cancer tissues and its expression level is critical for lung cancer cell proliferation, which may serve as a prognostic marker for lung cancer patients. Meanwhile, we show that E3 ubiquitin ligase Smurf1 directly interacts with PIPKIγ and targets PIPKIγ for ubiquitination and degradation in lung cancer cells. Also, we discover that Smurf1 directly binds to the kinase domain of PIPKIγ via its C2 domain while Lysine 255 in PIPKIγ acts as the major ubiquitin acceptor site for Smurf1. In addition, we demonstrate that the phosphorylation mimicking mutant of Smurf1, Smurf1 T306D, prevents PIPKIγi2 from ubiquitination and subsequent degradation similar to the effect of forskolin-potentiated cAMP formation, suggesting that Thr306 in Smurf1 is critical for its phosphorylation by PKA. Moreover, PKA-Smurf1-PIPKIγ signal transduction takes a significant part in lung cancer cell growth and in vivo tumorigenesis. Thus, we propose that the PKA-Smurf1-PIPKIγ pathway has an important role in pulmonary tumorigenesis and imposes substantial clinical impact on development of novel diagnostic markers and therapeutic targets for lung cancer treatment.
- Published
- 2017
- Full Text
- View/download PDF
14. Differential regulation of LncRNA-SARCC suppresses VHL-mutant RCC cell proliferation yet promotes VHL-normal RCC cell proliferation via modulating androgen receptor/HIF-2α/C-MYC axis under hypoxia.
- Author
-
Zhai W, Sun Y, Jiang M, Wang M, Gasiewicz TA, Zheng J, and Chang C
- Abstract
This corrects the article DOI: 10.1038/sj.gt.3302808.
- Published
- 2017
- Full Text
- View/download PDF
15. An analysis of the polymorphisms of the GLUT1 gene in urothelial cell carcinomas of the bladder and its correlation with p53, Ki67 and GLUT1 expressions.
- Author
-
Xu C, Yang X, Wang Y, Ding N, Han R, Sun Y, and Wang Y
- Subjects
- Adult, Aged, Aged, 80 and over, Alleles, Carcinoma pathology, Case-Control Studies, Female, Gene Expression Regulation, Neoplastic, Gene Frequency, Genetic Predisposition to Disease, Genotype, Humans, Immunohistochemistry, Ki-67 Antigen metabolism, Male, Middle Aged, Neoplasm Grading, Neoplasm Staging, Tumor Suppressor Protein p53 metabolism, Urethral Neoplasms pathology, Carcinoma genetics, Glucose Transporter Type 1 genetics, Ki-67 Antigen genetics, Polymorphism, Single Nucleotide, Tumor Suppressor Protein p53 genetics, Urethral Neoplasms genetics
- Abstract
Frequencies of two glucose transporter 1 (GLUT1) single-nucleotide polymorphisms (SNPs) (XbaI G>T and HaeIII T>C) were studied with urothelial cell carcinomas of the bladder (UCC) and 204 normal persons. And the expression of the p53, Ki67 and GLUT1 was assayed by immunohistochemistry. The frequency of the TT genotype and T allele of the XbaI G>T SNP was decreased in the patients with UCC. The frequency of the CC genotype and C allele of the HaeIII T>C SNP was decreased in the patients with UCC. The GLUT1 XbaI genotype GG was more frequent in higher tumor stage and higher tumor grade patients. In the XbaI G>T SNP, the GG genotype was significantly related to higher Remmele immunoreactive score (IRS) of Ki67 and higher IRS of GLUT1. In conclusion, the TT genotype in XbaI G>T SNP and CC genotype of HaeIII T>C SNP may have protective effect in the carcinogenesis process of UCC. In the XbaI G>T SNP, the GG genotype of was positively related to tumor proliferation, glucose metabolism, tumor grade and stage. Therefore, the variant might become a possible proliferation-related prognostic factor for UCC.
- Published
- 2017
- Full Text
- View/download PDF
16. Coinjection of IL2 DNA enhances E7-specific antitumor immunity elicited by intravaginal therapeutic HPV DNA vaccination with electroporation.
- Author
-
Sun Y, Peng S, Yang A, Farmer E, Wu TC, and Hung CF
- Subjects
- Administration, Intravaginal, Animals, Calreticulin metabolism, Cell Line, Tumor, Cells, Cultured, Female, Interleukin-2 metabolism, Male, Mice, Mice, Inbred C57BL, Papillomavirus Infections immunology, T-Lymphocytes, Cytotoxic immunology, Uterine Cervical Neoplasms immunology, Calreticulin genetics, Electroporation methods, Interleukin-2 genetics, Papillomavirus Infections therapy, Papillomavirus Vaccines administration & dosage, Uterine Cervical Neoplasms therapy, Vaccines, DNA administration & dosage
- Abstract
The generation and use of therapeutic human papillomavirus (HPV) DNA vaccines represent an appealing treatment method against HPV-associated cervical cancer owing to their safety and durability. Previously, we created a therapeutic HPV DNA vaccine candidate by linking the HPV16-E7 DNA sequence to calreticulin (CRT/E7), which we showed could generate significant E7-specific cytotoxic T lymphocyte (CTL)-mediated antitumor immune responses against HPV16 oncogenes expressing murine tumor model TC-1. Here we assess the therapeutic efficacy of intravaginal immunization with pcDNA3-CRT/E7 followed by electroporation. In addition, we examined whether coadministration of DNA-encoding interleukin 2 (IL2) with the pcDNA3-CRT/E7 could improve the T-cell responses elicited by pcDNA3-CRT/E7. TC-1 tumor-bearing mice vaccinated intravaginally with both pcDNA3-CRT/E7 and IL2 DNA followed by electroporation induced stronger local antitumor CTL response in comparison to mice that received other treatment regimens. Additionally, we found that coadministration of IL2 DNA with pcDNA3-CRT/E7 modified the tumor microenvironment by decreasing the population of regulatory T cells and myeloid-derived suppressor cells relative to that of CTLs. Our data demonstrate the translational potential of local administration of IL2 and pcDNA3-CRT/E7 followed by electroporation in treating cervicovaginal tumors.
- Published
- 2017
- Full Text
- View/download PDF
17. Downregulation of PCK2 remodels tricarboxylic acid cycle in tumor-repopulating cells of melanoma.
- Author
-
Luo S, Li Y, Ma R, Liu J, Xu P, Zhang H, Tang K, Ma J, Liu N, Zhang Y, Sun Y, Ji T, Liang X, Yin X, Liu Y, Tong W, Niu Y, Wang N, Wang X, and Huang B
- Subjects
- Animals, Cell Line, Tumor, Female, Humans, Melanoma genetics, Melanoma pathology, Mice, Mice, Nude, Neoplasm Proteins genetics, Oxidative Phosphorylation, Phosphoenolpyruvate Carboxykinase (ATP) genetics, Citric Acid Cycle, Down-Regulation, Gene Expression Regulation, Enzymologic, Gene Expression Regulation, Neoplastic, Melanoma metabolism, Neoplasm Proteins biosynthesis, Phosphoenolpyruvate Carboxykinase (ATP) biosynthesis
- Abstract
For cancer cells to proliferate, a balance must be built between biomass-forming, glucose-metabolized intermediates and ATP production. How intrinsic glucose carbon flow regulates this balance remains unclear. Here we show that mitochondrial phosphoenolpyruvate carboxykinase (PCK2), the hub molecule linking tricarboxylic acid (TCA) cycle, glycolysis and gluconeogenesis by conversion of mitochondrial oxaloacetate (OAA) to phosphoenolpyruvate, regulates glucose carbon flow direction in stem-like cells that repopulate tumors (tumor-repopulating cells (TRCs)). PCK2 downregulation accelerated biosynthesis and transportation of citrate from mitochondria to the cytosol, leading to cytosolic glucose carbon flow via OAA-malate-pyruvate and acetyl-CoA-fatty acid pathways in TRCs. On the other hand, downregulating PCK2 hindered fumarate carbon flows in TCA cycle, leading to attenuated oxidative phosphorylation. In pathological terms, PCK2 overexpression slowed TRC growth in vitro and impeded tumorigenesis in vivo. Overall, our work unveiled unexpected glucose carbon flows of TRCs in melanoma that have implications for targeting metabolic aspects of melanoma.
- Published
- 2017
- Full Text
- View/download PDF
18. SPARCS and Pelli-Robson contrast sensitivity testing in normal controls and patients with cataract.
- Author
-
Gupta L, Cvintal V, Delvadia R, Sun Y, Erdem E, Zangalli C, Lu L, Wizov SS, Richman J, Spaeth E, and Spaeth GL
- Subjects
- Aged, Cataract complications, Cataract diagnosis, Cross-Sectional Studies, Female, Humans, Male, Middle Aged, Prospective Studies, Vision Disorders etiology, Vision Disorders physiopathology, Cataract physiopathology, Contrast Sensitivity physiology, Internet, Vision Disorders diagnosis, Vision Tests methods, Visual Acuity
- Abstract
PurposeTo determine the ability of the newly developed internet-based Spaeth/Richman Contrast Sensitivity (SPARCS) test to assess contrast sensitivity centrally and peripherally in cataract subjects and controls, in comparison with the Pelli-Robson (PR) test.MethodsIn this prospective cross-sectional study, cataract subjects and age-matched normal controls were evaluated using the SPARCS and PR tests. Contrast sensitivity testing was performed in each eye twice in a standardized testing environment in randomized order. SPARCS scores were obtained for central, right upper (RUQ), right lower (RLQ), left upper (LUQ), and left lower quadrants (LLQ). PR scores were obtained for central contrast sensitivity. PR and SPARCS scores in cataract subjects were compared with controls. Intraclass correlation coefficients (ICC) and Bland Altman analysis were used to determine test-retest reliability and correlation.ResultsA total of 162 eyes from 84 subjects were analyzed: 43 eyes from 23 cataract subjects, and 119 eyes from 61 controls. The mean scores for SPARCS centrally were 13.4 and 14.5 in the cataract and control groups, respectively (P=0.001). PR mean scores were 1.31 and 1.45 in cataract and control groups, respectively (P<0.001). ICC values for test-retest reliability for cataract subjects were 0.75 for PR and 0.61 for the SPARCS total. There was acceptable agreement between the ability of PR and SPARCS to detect the effect of cataract on central contrast sensitivity.ConclusionsBoth SPARCS and PR demonstrate a significant influence of cataract on contrast sensitivity. SPARCS offers the advantage of determining contrast sensitivity peripherally and centrally, without being influenced by literacy.
- Published
- 2017
- Full Text
- View/download PDF
19. Androgen receptor promotes melanoma metastasis via altering the miRNA-539-3p/USP13/MITF/AXL signals.
- Author
-
Wang Y, Ou Z, Sun Y, Yeh S, Wang X, Long J, and Chang C
- Subjects
- Animals, Cell Line, Tumor, Cell Movement genetics, Cluster Analysis, Disease Models, Animal, Female, Gene Expression, Gene Expression Profiling, Heterografts, Humans, Male, Melanoma mortality, Melanoma pathology, Mice, Middle Aged, Neoplasm Invasiveness, Prognosis, RNA Interference, Receptors, Androgen genetics, Tumor Burden, Ubiquitin-Specific Proteases, Axl Receptor Tyrosine Kinase, Endopeptidases genetics, Gene Expression Regulation, Neoplastic, Melanoma genetics, Melanoma metabolism, MicroRNAs genetics, Microphthalmia-Associated Transcription Factor metabolism, Proto-Oncogene Proteins metabolism, Receptor Protein-Tyrosine Kinases metabolism, Receptors, Androgen metabolism, Signal Transduction
- Abstract
Early studies demonstrated that male melanoma patients have worse survival than female patients, yet the detailed mechanisms for this gender difference remain unclear. We analyzed around 100 cases of human melanoma and found that androgen receptor (AR) positive melanoma patients have worse survival outcomes compared with AR-negative melanoma patients. Here we report that AR can have positive roles to increase melanoma cell invasion in multiple cell lines in vitro and a mouse model in vivo. Mechanism dissection suggest that AR increases melanoma cell invasion via modulating the MITF-AXL signals via altering the miRNA-539-3p/USP13 signaling to increase MITF protein degradation through a reduction of de-ubiquitination. Restoring MITF can reverse AR-enhanced melanoma cell invasion. Together, our results demonstrate that AR can promote melanoma metastasis via altering the miRNA-539-3p/USP13/MITF/AXL signal and targeting this newly identified signal with AR degradation enhancer ASC-J9 may help us to better suppress the melanoma metastasis.
- Published
- 2017
- Full Text
- View/download PDF
20. A novel FOXM1 isoform, FOXM1D, promotes epithelial-mesenchymal transition and metastasis through ROCKs activation in colorectal cancer.
- Author
-
Zhang X, Zhang L, Du Y, Zheng H, Zhang P, Sun Y, Wang Y, Chen J, Ding P, Wang N, Yang C, Huang T, Yao X, Qiao Q, Gu H, Cai G, Cai S, Zhou X, and Hu W
- Subjects
- Animals, Cell Line, Tumor, Epithelial-Mesenchymal Transition, Forkhead Box Protein M1 genetics, Heterografts, Humans, Male, Mice, Mice, Inbred BALB C, Mice, Nude, Protein Isoforms, Signal Transduction, Transfection, rho-Associated Kinases genetics, Colorectal Neoplasms metabolism, Colorectal Neoplasms pathology, Forkhead Box Protein M1 metabolism, rho-Associated Kinases metabolism
- Abstract
Epithelial-mesenchymal transition (EMT) is a critical event in metastasis of colorectal cancer (CRC). Rho/ROCKs signaling has a pivotal role in orchestrating actin cytoskeleton, leading to EMT and cancer invasion. However, the underlying mechanisms for ROCKs activation are not fully understood. Here, we identified FOXM1D, a novel isoform of Forkhead box M1 (FOXM1) that has a pivotal role in ROCKs activation by directly interacting with coiled-coil region of ROCK2. FOXM1D overexpression significantly polymerizes actin assembly and impairs E-cadherin expression, resulting in EMT and metastasis in xenograft mouse model and knockdown of FOXM1D has the opposite effect. Moreover, a high FOXM1D level correlates closely with clinical CRC metastasis. FOXM1D-induced ROCKs activation could be abrogated by the ROCKs inhibitors Y-27632 and fasudil. These observations indicate that the FOXM1D-ROCK2 interaction is crucial for Rho/ROCKs signaling and provide novel insight into actin cytoskeleton regulation and therapeutic potential for CRC metastasis.
- Published
- 2017
- Full Text
- View/download PDF
21. Conditional control of suicide gene expression in tumor cells with theophylline-responsive ribozyme.
- Author
-
Zhang Y, Wang J, Cheng H, Sun Y, Liu M, Wu Z, and Pei R
- Subjects
- A549 Cells, Bronchodilator Agents pharmacology, Green Fluorescent Proteins genetics, Green Fluorescent Proteins metabolism, HeLa Cells, Humans, Lung Neoplasms drug therapy, Lung Neoplasms genetics, Thymidine Kinase genetics, Thymidine Kinase metabolism, Gene Expression Regulation, Enzymologic drug effects, Genes, Transgenic, Suicide genetics, Genetic Engineering, Lung Neoplasms metabolism, RNA, Catalytic genetics, Theophylline pharmacology
- Abstract
Numerous synthetic RNA-based controls for integrating sensing switches with function devices have been demonstrated in a variety of organisms for gene regulation. Although potential advantages of RNA-based genetic control strategies have been shown in clinical applications, successfully extending these engineered systems into medical applications has seldom been reported. Here, a synthetic RNA-based ribozyme system and its application in advancing rationally designed cellular therapy were described. The theophylline-responsive, ribozyme-based device provided a powerful platform for suicide gene expression regulation in tumor cells. Moreover, we demonstrate the ability of our synthetic controller to modulate effectively the viability of the cells in response to drug input. Our RNA-based regulatory system could dose-dependently fine-tune transgene expression in mammalian cells and address urgent limitations in existing genetic control strategies for gene- and cell-based therapies in the future.
- Published
- 2017
- Full Text
- View/download PDF
22. Neuroendocrine prostate cancer (NEPCa) increased the neighboring PCa chemoresistance via altering the PTHrP/p38/Hsp27/androgen receptor (AR)/p21 signals.
- Author
-
Cui Y, Sun Y, Hu S, Luo J, Li L, Li X, Yeh S, Jin J, and Chang C
- Subjects
- Animals, Antineoplastic Agents pharmacology, Carcinoma, Neuroendocrine drug therapy, Cell Line, Tumor, Disease Models, Animal, Docetaxel, Humans, Male, Prostatic Neoplasms drug therapy, Protein Kinase Inhibitors pharmacology, Taxoids pharmacology, Xenograft Model Antitumor Assays, Carcinoma, Neuroendocrine metabolism, Drug Resistance, Neoplasm, HSP27 Heat-Shock Proteins metabolism, Prostatic Neoplasms metabolism, Receptor, Parathyroid Hormone, Type 1 metabolism, Receptors, Androgen metabolism, Signal Transduction drug effects, p38 Mitogen-Activated Protein Kinases metabolism
- Abstract
Prostatic neuroendocrine cells (NE) are an integral part of prostate cancer (PCa) and are associated with PCa progression. As the current androgen deprivation therapy with anti-androgens may promote the neuroendocrine PCa (NEPCa) development, and few therapies can effectively suppress NEPCa, understanding the impact of NEPCa on PCa progression may help us to develop better therapies to battle PCa. Here, we found NEPCa cells could increase the docetaxel resistance of their neighboring PCa cells. Mechanism dissection revealed that through secretion of PTHrP, NEPCa cells could alter the p38/MAPK/Hsp27 signals in their neighboring PCa cells that resulted in increased androgen receptor (AR) activity via promoting AR nuclear translocation. The consequences of increased AR function might then increase docetaxel resistance via increasing p21 expression. In vivo xenograft mice experiments also confirmed that NEPCa could increase the docetaxel resistance of neighboring PCa, and targeting this newly identified PTHrP/p38/Hsp27/AR/p21 signaling pathway with either p38 inhibitor (SB203580) or shPTHrP may result in improving/restoring the docetaxel sensitivity to better suppress PCa., Competing Interests: The authors declare no conflict of interest.
- Published
- 2016
- Full Text
- View/download PDF
23. Differential regulation of LncRNA-SARCC suppresses VHL-mutant RCC cell proliferation yet promotes VHL-normal RCC cell proliferation via modulating androgen receptor/HIF-2α/C-MYC axis under hypoxia.
- Author
-
Zhai W, Sun Y, Jiang M, Wang M, Gasiewicz TA, Zheng J, and Chang C
- Subjects
- Carcinoma, Renal Cell pathology, Cell Line, Tumor, Cell Proliferation genetics, Gene Expression Regulation, Neoplastic, Humans, Promoter Regions, Genetic, Proto-Oncogene Proteins c-myc genetics, Signal Transduction genetics, Basic Helix-Loop-Helix Transcription Factors genetics, Carcinoma, Renal Cell genetics, RNA, Long Noncoding genetics, Receptors, Androgen genetics, Von Hippel-Lindau Tumor Suppressor Protein genetics
- Abstract
It is well established that hypoxia contributes to tumor progression in a hypoxia inducible factor-2α (HIF-2α)-dependent manner in renal cell carcinoma (RCC), yet the role of long noncoding RNAs (LncRNAs) involved in hypoxia-mediated RCC progression remains unclear. Here we demonstrate that LncRNA-SARCC (Suppressing Androgen Receptor in Renal Cell Carcinoma) is differentially regulated by hypoxia in a von Hippel-Lindau (VHL)-dependent manner both in RCC cell culture and clinical specimens. LncRNA-SARCC can suppress hypoxic cell cycle progression in the VHL-mutant RCC cells while derepress it in the VHL-restored RCC cells. Mechanism dissection reveals that LncRNA-SARCC can post-transcriptionally regulate androgen receptor (AR) by physically binding and destablizing AR protein to suppress AR/HIF-2α/C-MYC signals. In return, HIF-2α can transcriptionally regulate the LncRNA-SARCC expression via binding to hypoxia-responsive elements on the promoter of LncRNA-SARCC. The negative feedback modulation between LncRNA-SARCC/AR complex and HIF-2α signaling may then lead to differentially modulated RCC progression in a VHL-dependent manner. Together, these results may provide us a new therapeutic approach via targeting this newly identified signal from LncRNA-SARCC to AR-mediated HIF-2α/C-MYC signals against RCC progression.
- Published
- 2016
- Full Text
- View/download PDF
24. SFRP2 augments WNT16B signaling to promote therapeutic resistance in the damaged tumor microenvironment.
- Author
-
Sun Y, Zhu D, Chen F, Qian M, Wei H, Chen W, and Xu J
- Subjects
- Apoptosis, Cell Line, Tumor, DNA Damage, Drug Resistance, Neoplasm, Humans, Intercellular Signaling Peptides and Proteins physiology, Low Density Lipoprotein Receptor-Related Protein-6 physiology, NF-kappa B physiology, Wnt Proteins antagonists & inhibitors, beta Catenin physiology, Membrane Proteins physiology, Neoplasms drug therapy, Signal Transduction physiology, Tumor Microenvironment physiology, Wnt Proteins physiology
- Abstract
Most tumors initially respond to cytotoxic treatments, but acquired resistance often follows. The tumor microenvironment (TME) is a major barrier to clinical success by compromising therapeutic efficacy, and pathological relevance of multiple soluble factors released by a therapeutically remodeled TME remains largely unexplored. Here we show that the secreted frizzled-related protein 2 (SFRP2), a Wnt pathway modulator, is produced by human primary fibroblasts after genotoxic treatments. SFRP2 induction is remarkable in tumor stroma, with transcription mainly modulated by the nuclear factor-κB (NF-κB) complex, a property shared by several effectors of the DNA damage secretory program. Instead of directly altering canonical Wnt signaling, SFRP2 augments β-catenin activities initiated by WNT16B, another soluble factor from DNA-damaged stroma. WNT16B recognizes cancer cell surface receptors including frizzled (FZD) 3/4/6, a process enhanced by SFRP2, coordinated by the co-receptor LRP6 but subject to abrogation by DKK1. Importantly, we found WNT16B plays a central role in promoting advanced malignancies particularly acquired resistance by counteracting cell death, an effect that can be minimized by a neutralizing antibody co-administered with classical chemotherapy. Furthermore, DNA damage-triggered expression of WNT16B is systemic, imaged by significant induction among diverse solid organs and circulation in peripheral blood, thereby holding promise as not only a TME-derived anticancer target but also a novel biomarker for clinical evaluation of treatment efficacy. Overall, our study substantiates the biological complexity and pathological implication of a therapy-activated TME, and provides the proof of principle of co-targeting tumor and the TME to prevent acquired resistance, with the aim of improving intervention outcome in an era of precision medicine.
- Published
- 2016
- Full Text
- View/download PDF
25. Hyperhomocysteinemia independently associated with the risk of hypertension: a cross-sectional study from rural China.
- Author
-
Li Z, Guo X, Chen S, Zheng L, Yang H, Sun G, Yu S, Li W, Zhou L, Wang J, Hu W, and Sun Y
- Subjects
- Adult, Age Distribution, Aged, Biomarkers blood, Blood Pressure, Chi-Square Distribution, China, Cross-Sectional Studies, Female, Humans, Hyperhomocysteinemia blood, Hyperhomocysteinemia diagnosis, Hypertension diagnosis, Hypertension physiopathology, Incidence, Logistic Models, Male, Middle Aged, Multivariate Analysis, Odds Ratio, Prevalence, Risk Assessment, Risk Factors, Sex Distribution, Up-Regulation, Homocysteine blood, Hyperhomocysteinemia epidemiology, Hypertension epidemiology, Rural Health
- Abstract
This study was designed to investigate the current prevalence of hyperhomocysteinemia (Hhcy) and its association with hypertension in rural adults of Northeast China. A cross-sectional study was performed in subjects aged⩾35 years in a general Chinese population. Demographic data, laboratory examination of traditional cardiovascular risk factors and self-reported information on lifestyle factors, such as physical activities, current smoking and drinking status, dietary habits and familial factors were collected by trained personnel. A total of 7130 participants (3317 men and 3813 women) were included in this study and the mean Hhcy level of the whole population was 17.39±12.34 mmol l(-1), which was 20.99±14.83 mmol l(-1) in males and 14.19±8.51 mmol l(-1) in females, respectively. Prevalence of Hhcy in total population was 41.3%. Stratified by gender, the prevalence of Hhcy was higher in males than in females (59.0 vs 25.8%, P<0.05). After adjustment for conventional risk factors including age, salt intake, smoking, body mass index, diabetes, dyslipidemia, activity time and family history, multiple logistic regression analysis showed that Hhcy was independently associated with the risk of hypertension in males (odds ratio (OR)=1.501, 95% confidence interval (CI): 1.012-2.227; P<0.001), but not in females in this population (OR=1.182; 95% CI, 0.993-1.407; P=0.060). In conclusion, a high prevalence of Hhcy in the general adult population of rural northeast China was detected and Hhcy may be a risk factor for hypertension, particularly in males.
- Published
- 2016
- Full Text
- View/download PDF
26. AAV1/2-mediated BDNF gene therapy in a transgenic rat model of Huntington's disease.
- Author
-
Connor B, Sun Y, von Hieber D, Tang SK, Jones KS, and Maucksch C
- Subjects
- Animals, Animals, Genetically Modified, Dependovirus genetics, Female, Genetic Vectors, Male, Models, Animal, Rats, Brain-Derived Neurotrophic Factor genetics, Brain-Derived Neurotrophic Factor therapeutic use, Corpus Striatum physiopathology, Genetic Therapy, Huntington Disease genetics, Huntington Disease therapy
- Abstract
Reduced expression and disrupted corticostriatal transportation of brain-derived neurotrophic factor (BDNF) is proposed to contribute to the selective vulnerability of medium spiny striatal projection neurons (MSNs) in Huntington's disease (HD). We have previously demonstrated that BDNF overexpression in the quinolinic acid lesioned rat striatum attenuates motor impairment and reduces the extent of MSN cell loss. To further investigate the potential therapeutic properties of BDNF for HD, the current study examines the effect of bilateral AAV1/2-mediated BDNF expression in the striatum of a transgenic rat model of HD. Transfer of the BDNF gene to striatal neurons using an AAV1/2 serotype vector enhanced BDNF protein levels in the striatum. Bilateral BDNF expression attenuated the impairment of both motor and cognitive function when compared with AAV1/2-vehicle- or YFP-treated transgenic HD rats. Interestingly, a gender effect was apparent with female transgenic HD rats exhibiting less functional impairment than males. Quantification of NeuN and DARRP32 immunoreactivity and striatal volume revealed limited disease phenotype between wild type and transgenic HD animals. However, AAV1/2-BDNF-treated transgenic HD rats showed evidence of greater striatal volume and increased NeuN+ cell numbers compared with wild-type vehicle- and AAV1/2-vehicle- or YFP-treated transgenic HD rats. We propose BDNF holds considerable therapeutic potential for alleviating behavioral dysfunction and neuronal degeneration in HD, with further work required to examine the role of BDNF-TrkB signaling and the preservation of axonal and synaptic function.
- Published
- 2016
- Full Text
- View/download PDF
27. Plasma EGFR T790M ctDNA status is associated with clinical outcome in advanced NSCLC patients with acquired EGFR-TKI resistance.
- Author
-
Zheng D, Ye X, Zhang MZ, Sun Y, Wang JY, Ni J, Zhang HP, Zhang L, Luo J, Zhang J, Tang L, Su B, Chen G, Zhu G, Gu Y, and Xu JF
- Subjects
- Carcinoma, Non-Small-Cell Lung drug therapy, Carcinoma, Non-Small-Cell Lung pathology, Disease Progression, ErbB Receptors genetics, Female, Humans, Lung Neoplasms drug therapy, Lung Neoplasms pathology, Male, Middle Aged, Neoplasm Staging, Neoplastic Cells, Circulating metabolism, Polymerase Chain Reaction, Protein Kinase Inhibitors pharmacology, Reproducibility of Results, Survival Analysis, Treatment Outcome, Carcinoma, Non-Small-Cell Lung blood, DNA, Neoplasm blood, Drug Resistance, Neoplasm drug effects, ErbB Receptors blood, Lung Neoplasms blood, Mutation genetics, Protein Kinase Inhibitors therapeutic use
- Abstract
EGFR T790M mutation occurs in half of non-small cell lung cancer (NSCLC) patients with acquired EGFR-TKI (TKI) resistance, based on tumor re-biopsies using an invasive clinical procedure. Here, we dynamically monitored T790M mutation in circulating tumor DNA (ctDNA) using serial plasma samples from NSCLC patients receiving TKI through Droplet Digital PCR (ddPCR) method and the associations between overall survival (OS) starting from initial TKI treatment and the T790M ctDNA status detected in plasma were analyzed. Among 318 patients, 117 who acquired TKI resistance were eligible for the analysis. T790M ctDNA was detected in the plasma of 55/117 (47%) patients. Almost half of the T790M ctDNA positive patients were identified at a median time of 2.2 months prior to clinically progressive disease (PD). Furthermore, within the patients receiving TKI treatment at 2(nd) line or later, the T790M ctDNA positive group had significantly shorter OS than the negative group (median OS: 26.9 months versus NA, P = 0.0489). Our study demonstrates the feasibility of monitoring EGFR mutation dynamics in serial plasma samples from NSCLC patients receiving TKI therapy. T790M ctDNA can be detected in plasma before and after PD as a poor prognostic factor.
- Published
- 2016
- Full Text
- View/download PDF
28. The spread of adenoviral vectors to central nervous system through pathway of cochlea in mimetic aging and young rats.
- Author
-
Chen X, Zhao X, Hu Y, Lan F, Sun H, Fan G, Sun Y, Wu J, Kong W, and Kong W
- Subjects
- Age Factors, Animals, Central Nervous System metabolism, Cochlea metabolism, DNA, Mitochondrial genetics, DNA, Mitochondrial metabolism, Ear, Inner metabolism, Ear, Inner virology, Female, Galactose metabolism, Genetic Vectors administration & dosage, Microscopy, Electron, Transmission, Rats, Rats, Sprague-Dawley, Round Window, Ear metabolism, Transfection methods, Adenoviridae physiology, Central Nervous System virology, Cochlea virology, Genetic Vectors pharmacokinetics, Round Window, Ear virology
- Abstract
There is no definitive conclusion concerning the spread of viral vectors to the brain after a cochlear inoculation. In addition, some studies have reported different distribution profiles of viral vectors in the central auditory system after a cochlear inoculation. Thus, rats were grouped into either a mimetic aging group or a young group and transfected with adenoviral vectors (AdVs) by round window membrane injection. The distribution of AdV in central nervous system (CNS) was demonstrated in the two groups with transmission electron microscopy and immunofluorescence. We found that the AdV could disseminate into the CNS and that the neuronal damage and stress-induced GRP78 expression were reduced after transfection with PGC-1α, as compared with the control vectors, especially in the mimetic aging group. We also found that the host immune response was degraded in CNS in the mimetic aging group after transduction through the cochlea, as compared with the young group. These results demonstrate that viral vectors can disseminate into the CNS through the cochlea. Moreover, mimetic aging induced by D-galactose could facilitate the spread of viral vectors into the CNS from the cochlea. These findings may indicate a new potential approach for gene therapy against age-related diseases in the CNS.
- Published
- 2015
- Full Text
- View/download PDF
29. Involvement of tumor suppressors PTEN and p53 in the formation of multiple subtypes of liposarcoma.
- Author
-
Puzio-Kuter AM, Laddha SV, Castillo-Martin M, Sun Y, Cordon-Cardo C, Chan CS, and Levine AJ
- Subjects
- Animals, Cell Division physiology, Cyclin-Dependent Kinase 4 genetics, Cyclin-Dependent Kinase 4 metabolism, Cyclin-Dependent Kinase 6 genetics, Cyclin-Dependent Kinase 6 metabolism, Female, Liposarcoma genetics, Male, Mice, PTEN Phosphohydrolase genetics, Tumor Suppressor Protein p53 genetics, Liposarcoma metabolism, Liposarcoma pathology, PTEN Phosphohydrolase metabolism, Tumor Suppressor Protein p53 metabolism
- Abstract
Liposarcoma (LPS) is a type of soft tissue sarcoma that mostly occurs in adults, and in humans is characterized by amplifications of MDM2 and CDK4. The molecular pathogenesis of this malignancy is still poorly understood and, therefore, we developed a mouse model with conditional inactivation of PTEN and p53 to investigate these pathways in the progression of the disease. We show that deletion of these two tumor suppressors cooperate in the formation of multiple subtypes of LPS (from well-differentiated LPS to pleomorphic LPS). In addition, progression of the tumors is further characterized by the expression of D cyclins and CDK4/6, which allow for continued cell division. Microarray analysis also revealed novel genes that are differentially expressed between different subtypes of LPS, which could aid in understanding the disease and to unravel potential new therapeutic targets.
- Published
- 2015
- Full Text
- View/download PDF
30. STIM1 overexpression promotes colorectal cancer progression, cell motility and COX-2 expression.
- Author
-
Wang JY, Sun J, Huang MY, Wang YS, Hou MF, Sun Y, He H, Krishna N, Chiu SJ, Lin S, Yang S, and Chang WC
- Subjects
- Caco-2 Cells, Carcinoembryonic Antigen blood, Cell Line, Tumor, Colorectal Neoplasms blood, Dinoprostone genetics, Disease Progression, Female, HCT116 Cells, HT29 Cells, Humans, Lymphatic Metastasis genetics, Lymphatic Metastasis pathology, Male, Middle Aged, RNA, Small Interfering genetics, Stromal Interaction Molecule 1, Cell Movement genetics, Colorectal Neoplasms genetics, Colorectal Neoplasms pathology, Cyclooxygenase 2 genetics, Membrane Proteins genetics, Neoplasm Proteins genetics
- Abstract
Tumor metastasis is the major cause of death among cancer patients, with >90% of cancer-related death attributable to the spreading of metastatic cells to secondary organs. Store-operated Ca(2+) entry (SOCE) is the predominant Ca(2+) entry mechanism in most cancer cells, and stromal interaction molecule 1 (STIM1) is the endoplasmic reticulum (ER) Ca(2+) sensor for store-operated channels. Here we reported that the STIM1 was overexpressed in colorectal cancer (CRC) patients. STIM1 overexpression in CRC was significantly associated with tumor size, depth of invasion, lymph node metastasis status and serum levels of carcinoembryonic antigen. Furthermore, ectopic expression of STIM1 promoted CRC cell motility, while depletion of STIM1 with short hairpin RNA inhibited CRC cell migration. Our data further suggested that STIM1 promoted CRC cell migration through increasing the expression of cyclooxygenase-2 (COX-2) and production of prostaglandin E2 (PGE2). Importantly, ectopically expressed COX-2 or exogenous PGE2 were able to rescue migration defect in STIM1 knockdown CRC cells, and inhibition of COX-2 with ibuprofen and indomethacin abrogated STIM1-mediated CRC cell motility. In short, our data provided clinicopathological significance for STIM1 and SOCE in CRC progression, and implicated a role for COX-2 in STIM1-mediated CRC metastasis. Our studies also suggested a new approach to inhibit STIM1-mediated metastasis with COX-2 inhibitors.
- Published
- 2015
- Full Text
- View/download PDF
31. Topoisomerase IIα in chromosome instability and personalized cancer therapy.
- Author
-
Chen T, Sun Y, Ji P, Kopetz S, and Zhang W
- Subjects
- Animals, Chromosome Segregation genetics, DNA-Binding Proteins antagonists & inhibitors, Disease Progression, Humans, Neoplasms genetics, Poly-ADP-Ribose Binding Proteins, Topoisomerase II Inhibitors therapeutic use, Antigens, Neoplasm physiology, Chromosomal Instability, DNA Topoisomerases, Type II physiology, DNA-Binding Proteins physiology, Neoplasms drug therapy, Precision Medicine methods
- Abstract
Genome instability is a hallmark of cancer cells. Chromosome instability (CIN), which is often mutually exclusive from hypermutation genotypes, represents a distinct subtype of genome instability. Hypermutations in cancer cells are due to defects in DNA repair genes, but the cause of CIN is still elusive. However, because of the extensive chromosomal abnormalities associated with CIN, its cause is likely a defect in a network of genes that regulate mitotic checkpoints and chromosomal organization and segregation. Emerging evidence has shown that the chromosomal decatenation checkpoint, which is critical for chromatin untangling and packing during genetic material duplication, is defective in cancer cells with CIN. The decatenation checkpoint is known to be regulated by a family of enzymes called topoisomerases. Among them, the gene encoding topoisomerase IIα (TOP2A) is commonly altered at both gene copy number and gene expression level in cancer cells. Thus, abnormal alterations of TOP2A, its interacting proteins, and its modifications may have a critical role in CIN in human cancers. Clinically, a large arsenal of topoisomerase inhibitors has been used to suppress DNA replication in cancer. However, they often lead to the secondary development of leukemia because of their effect on the chromosomal decatenation checkpoint. Therefore, topoisomerase drugs must be used judiciously and administered on an individual basis. In this review, we highlight the biological function of TOP2A in chromosome segregation and the mechanisms that regulate this enzyme's expression and activity. We also review the roles of TOP2A and related proteins in human cancers, and raise a perspective for how to target TOP2A in personalized cancer therapy.
- Published
- 2015
- Full Text
- View/download PDF
32. MiR-873 regulates ERα transcriptional activity and tamoxifen resistance via targeting CDK3 in breast cancer cells.
- Author
-
Cui J, Yang Y, Li H, Leng Y, Qian K, Huang Q, Zhang C, Lu Z, Chen J, Sun T, Wu R, Sun Y, Song H, Wei X, Jing P, Yang X, and Zhang C
- Published
- 2015
- Full Text
- View/download PDF
33. MiR-873 regulates ERα transcriptional activity and tamoxifen resistance via targeting CDK3 in breast cancer cells.
- Author
-
Cui J, Yang Y, Li H, Leng Y, Qian K, Huang Q, Zhang C, Lu Z, Chen J, Sun T, Wu R, Sun Y, Song H, Wei X, Jing P, Yang X, and Zhang C
- Subjects
- Animals, Base Sequence, Binding Sites, Breast Neoplasms drug therapy, Breast Neoplasms genetics, Cell Proliferation, Cyclin-Dependent Kinase 3 metabolism, Drug Resistance, Neoplasm, Female, Gene Expression Regulation, Enzymologic, Gene Expression Regulation, Neoplastic, Humans, MCF-7 Cells, Mice, Nude, Phosphorylation, Protein Processing, Post-Translational, RNA Interference, Transcriptional Activation, Xenograft Model Antitumor Assays, Antineoplastic Agents, Hormonal pharmacology, Breast Neoplasms enzymology, Cyclin-Dependent Kinase 3 genetics, Estrogen Receptor alpha physiology, MicroRNAs physiology, Tamoxifen pharmacology
- Abstract
miRNAs (microRNAs) are frequently and aberrantly expressed in many cancers. MiR-873 has been revealed to be downregulated in colorectal cancer and glioblastoma. However, its function remains unclear. Here we report that miR-873 is downregulated in breast tumor compared with normal tissue. Enforced expression of miR-873 decreases the transcriptional activity of ER (estrogen receptor)-α but not ERβ through the modulation of ERα phosphorylation in ER-positive breast cancer cells. We also found that miR-873 inhibits breast cancer cell proliferation and tumor growth in nude mice. Reporter gene assays revealed cyclin-dependent kinase 3 (CDK3) as a direct target of miR-873. CDK3 was shown to be overexpressed in breast cancer and phosphorylate ERα at Ser104/116 and Ser118. Furthermore, we found that Mir-873 inhibits ER activity and cell growth via targeting CDK3. Interestingly, miR-873 was observed to be downregulated in tamoxifen-resistant MCF-7/TamR cells, while CDK3 is overexpressed in these cells. More importantly, re-expression of miR-873 reversed tamoxifen resistance in MCF-7/TamR cells. Our data demonstrate that miR-873 is a novel tumor suppressor in ER-positive breast cancer and a potential therapeutic approach for treatment of tamoxifen-resistant breast cancer.
- Published
- 2015
- Full Text
- View/download PDF
34. Intravaginal HPV DNA vaccination with electroporation induces local CD8+ T-cell immune responses and antitumor effects against cervicovaginal tumors.
- Author
-
Sun Y, Peng S, Qiu J, Miao J, Yang B, Jeang J, Hung CF, and Wu TC
- Subjects
- Administration, Intravaginal, Animals, Antineoplastic Agents administration & dosage, CD8-Positive T-Lymphocytes cytology, CD8-Positive T-Lymphocytes immunology, Cell Line, Tumor, Electroporation methods, Female, Mice, Inbred C57BL, Papillomavirus Vaccines administration & dosage, Uterine Cervical Neoplasms immunology, Uterine Cervical Neoplasms therapy, Vaccines, DNA administration & dosage, CD8-Positive T-Lymphocytes metabolism, Papillomavirus Vaccines immunology, Uterine Cervical Neoplasms prevention & control, Vaccines, DNA immunology
- Abstract
Therapeutic human papillomavirus (HPV) vaccines have the potential to inhibit the progression of an established HPV infection to precancer and cancer lesions by targeting HPV oncoproteins. We have previously developed a therapeutic DNA vaccine encoding calreticulin (CRT) linked to E7, CRT/E7 DNA vaccine, for use in the treatment of HPV-associated lesions. Since the transfection efficiency of DNA vaccines administered in vivo is typically low, we examined the use of electroporation as well as different routes of administration to enhance antigen-specific tumor control. We tested the effects of the CRT/E7 DNA vaccine administered intramuscularly or intravaginally, with or without electroporation, on the generation of CD8+ T-cell immunity and therapeutic antitumor effects in HPV16 E7-expressing cervicovaginal tumor-bearing mice. We found that intravaginal vaccination of CRT/E7 DNA followed by electroporation-induced potent E7-specific CD8(+) T-cell responses in the cervicovaginal tract, compared with intramuscular injection followed by electroporation. Furthermore, tumor-bearing mice vaccinated intravaginally followed by electroporation had an enhanced survival, antitumor effects and local production of IFN-γ+CD8+ T cells compared with those vaccinated intramuscularly with electroporation. Thus, we show that intravaginal CRT/E7 DNA vaccination followed by electroporation generates the most potent therapeutic antitumor effects against an orthotopic E7-expressing tumor model. The current study will have significant clinical implications once a clinically applicable electroporation device for intravaginal use becomes available.
- Published
- 2015
- Full Text
- View/download PDF
35. The PI3K/Akt signal hyperactivates Eya1 via the SUMOylation pathway.
- Author
-
Sun Y, Kaneko S, Li XK, and Li X
- Subjects
- Animals, Cell Line, Cell Movement genetics, Cell Proliferation, Cell Survival, Enzyme Activation, Female, HEK293 Cells, Humans, Intracellular Signaling Peptides and Proteins genetics, Mice, Mice, Inbred C57BL, Nuclear Proteins genetics, Phosphorylation, Protein Tyrosine Phosphatases genetics, RNA Interference, RNA, Small Interfering, Sumoylation, Transcription, Genetic genetics, Breast Neoplasms pathology, Cell Transformation, Neoplastic genetics, Intracellular Signaling Peptides and Proteins metabolism, Nuclear Proteins metabolism, Phosphatidylinositol 3-Kinases metabolism, Protein Tyrosine Phosphatases metabolism, Proto-Oncogene Proteins c-akt metabolism
- Abstract
Eyes absent 1 (Eya1) is a conserved critical regulator of organ-specific stem cells. Ectopic Eya1 activities, however, promote transformation of mammary epithelial cells. Signals that instigate Eya1 oncogenic activities remain to be determined. Here, we show that Akt1 kinase physically interacts with Eya1 and phosphorylates a conserved consensus site of the Akt kinase. PI3K/Akt signaling enhances Eya1 transcription activity, which largely attributes to the phosphorylation-induced reduction of Eya1 SUMOylation. Indeed, SUMOylation inhibits Eya1 transcription activity; and pharmacologic and genetic activation of PI3K/Akt robustly reduces Eya1 SUMOylation. Wild-type but not Akt phosphorylation site mutant Eya1 variant rescues the cell migratory phenotype of EYA1-silenced breast cancer cells, highlighting the importance of Eya1 phosphorylation. Furthermore, knockdown EYA1 sensitizes breast cancer cells to the PI3K/Akt1 inhibitor and irradiation treatments. Thus, the PI3K/Akt signal pathway activates Eya1. These findings further suggest that regulation of SUMOylation by PI3K/Akt signaling is likely an important aspect of tumorigenesis.
- Published
- 2015
- Full Text
- View/download PDF
36. Gene-gene interaction of CFH, ARMS2, and ARMS2/HTRA1 on the risk of neovascular age-related macular degeneration and polypoidal choroidal vasculopathy in Chinese population.
- Author
-
Huang L, Meng Q, Zhang C, Sun Y, Bai Y, Li S, Deng X, Wang B, Yu W, Zhao M, and Li X
- Subjects
- Adult, Aged, Aged, 80 and over, Asian People genetics, China, Choroidal Neovascularization diagnosis, Complement Factor H genetics, Female, Fluorescein Angiography, Gene Frequency, Genotype, High-Temperature Requirement A Serine Peptidase 1, Humans, Male, Middle Aged, Polymorphism, Single Nucleotide, Polyps diagnosis, Risk Factors, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Wet Macular Degeneration diagnosis, Choroidal Neovascularization genetics, Epistasis, Genetic genetics, Polyps genetics, Proteins genetics, Serine Endopeptidases genetics, Wet Macular Degeneration genetics
- Abstract
Purpose: To evaluate the association and interaction of five single-nucleotide polymorphisms (SNPs) in three genes (CFH, ARMS2, and ARMS2/HTRA1) with neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV) in Chinese population., Methods: A total of 300 nAMD and 300 PCV patients and 301 normal subjects participated in the present study. The allelic variants of rs800292, rs2274700, rs3750847, rs3793917, and rs1065489 were determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Gene-gene interactions were evaluated by the data mining approach multifactor-dimensionality reduction (MDR) method., Results: The risk alleles of CFH rs800292, rs2274700, ARMS2 rs3057847, and ARMS2/HTRA1 rs3793917 showed significant difference between nAMD or PCV patients and controls (all P<0.01). The homozygosity of risk alleles for rs800292, rs2274700, rs3750847, and rs3793917 were significantly different between nAMD patients and controls (all P<0.01), and predisposed to PCV patients (all P<0.01). After cross-validation consistency (CVC) and permutation tests, the two-locus model rs2274700_rs3750847 has a balanced accuracy of 64.37% in predicting nAMD disease risk. The one-marker model, rs3750847, and two-locus model rs2274700_rs3750847 has a balanced accuracy of 66.07% and 65.89% in predicting PCV disease risk, respectively. Furthermore, CFH rs1065489 did not show significant association with nAMD (P>0.01), but was strongly associated with PCV in Chinese patients (P<0.001)., Conclusions: In this study, we found that the interaction of ARMS2 and ARMS2/HTRA1 is significantly associated with nAMD, and the interaction of CFH and ARMS2 is pronounced in PCV development in Chinese population.
- Published
- 2015
- Full Text
- View/download PDF
37. Outcomes of extremely preterm infants after delivery room cardiopulmonary resuscitation in a population-based cohort.
- Author
-
Handley SC, Sun Y, Wyckoff MH, and Lee HC
- Subjects
- California, Cohort Studies, Delivery Rooms, Female, Gestational Age, Humans, Infant, Newborn, Male, Multivariate Analysis, Odds Ratio, Regression Analysis, Treatment Outcome, Cardiopulmonary Resuscitation statistics & numerical data, Epinephrine administration & dosage, Heart Massage methods, Infant, Extremely Low Birth Weight, Infant, Extremely Premature
- Abstract
Objective: To describe the relationship of delivery room cardiopulmonary resuscitation (DR-CPR) to short-term outcomes of extremely preterm infants., Study Design: This was a cohort study of 22 to 27+6/7 weeks gestational age (GA) infants during 2005 to 2011. DR-CPR was defined as chest compressions and/or epinephrine administration. Multivariable logistic regression was used to estimate odds ratios (ORs) with 95% confidence intervals (CIs) associated with DR-CPR; analysis was stratified by GA., Result: Of the 13 758 infants, 856 (6.2%) received DR-CPR. Infants 22 to 23+6/7 weeks receiving DR-CPR had similar outcomes to non-recipients. Infants 24 to 25+6/7 weeks receiving DR-CPR had more severe intraventricular hemorrhage (OR 1.36, 95% CI 1.07, 1.72). Infants 26 to 27+6/7 weeks receiving DR-CPR were more likely to die (OR 1.81, 95% CI 1.30, 2.51) and have intraventricular hemorrhage (OR 2.10, 95% CI 1.56, 2.82). Adjusted hospital DR-CPR rates varied widely (median 5.7%)., Conclusion: Premature infants receiving DR-CPR had worse outcomes. Mortality and morbidity varied by GA.
- Published
- 2015
- Full Text
- View/download PDF
38. Local structure order in Pd78Cu6Si16 liquid.
- Author
-
Yue GQ, Zhang Y, Sun Y, Shen B, Dong F, Wang ZY, Zhang RJ, Zheng YX, Kramer MJ, Wang SY, Wang CZ, Ho KM, and Chen LY
- Abstract
The short-range order (SRO) in Pd78Cu6Si16 liquid was studied by high energy x-ray diffraction and ab initio molecular dynamics (MD) simulations. The calculated pair correlation functions at different temperatures agree well with the experimental results. The partial pair correlation functions from ab intio MD simulations indicate that Si atoms prefer to be uniformly distributed while Cu atoms tend to aggregate. By performing structure analysis using Honeycutt-Andersen index, Voronoi tessellation, and atomic cluster alignment method, we show that the icosahedron and face-centered cubic SRO increase upon cooling. The dominant SRO is the Pd-centered Pd9Si2 motif, namely the structure of which motif is similar to the structure of Pd-centered clusters in the Pd9Si2 crystal. The study further confirms the existence of trigonal prism capped with three half-octahedra that is reported as a structural unit in Pd-based amorphous alloys. The majority of Cu-centered clusters are icosahedra, suggesting that the presence of Cu is benefit to promote the glass forming ability.
- Published
- 2015
- Full Text
- View/download PDF
39. Footprints of divergent selection in natural populations of Castanopsis fargesii (Fagaceae).
- Author
-
Li C, Sun Y, Huang HW, and Cannon CH
- Subjects
- Alleles, China, Evolution, Molecular, Expressed Sequence Tags, Gene Frequency, Genetics, Population, Microsatellite Repeats, Rain, Temperature, Trees genetics, Climate Change, Fagaceae genetics, Gene Flow, Genetic Variation, Selection, Genetic
- Abstract
Given predicted rapid climate change, an understanding of how environmental factors affect genetic diversity in natural populations is important. Future selection pressures are inherently unpredictable, so forest management policies should maintain both overall diversity and identify genetic markers associated with the environmental factors expected to change most rapidly, like temperature and rainfall. In this study, we genotyped 648 individuals in 28 populations of Castanopsis fargesii (Fagaceae) using 32 expressed sequence tag (EST)-derived microsatellite markers. After removing six loci that departed from Hardy-Weinberg equilibrium, we measured genetic variation, population structure and identified candidate loci putatively under selection by temperature and precipitation. We found that C. fargesii populations possessed high genetic diversity and moderate differentiation among them, indicating predominant outcrossing and few restrictions to gene flow. These patterns reduce the possible impact of stochastic effects or the influence of genetic isolation. Clear footprints of divergent selection at four loci were discovered. Frequencies of five alleles at these loci were strongly correlated with environmental factors, particularly extremes in precipitation. These alleles varied from being near fixation at one end of the gradient to being completely absent at the other. Our study species is an important forest tree in the subtropical regions of China and could have a major role in future management and reforestation plans. Our results demonstrate that the gene flow is widespread and abundant in natural populations, maintaining high diversity, while diversifying selection is acting on specific genomic regions.
- Published
- 2014
- Full Text
- View/download PDF
40. Si-doped ceramic Al4O4C nanowires: full-color emission and optical waveguide behavior.
- Author
-
Sun Y, Lei HX, Cui H, Yang GW, Li BJ, and Wang CX
- Abstract
The increasing prosperity of the photonics field has hastened the development of several sub-disciplines, with the aim to create advanced photonic devices, produce photonic circuits and eventually enable all-optical communication. This development has resulted in the demand for micro-nano-sized functional units with specific space dimensions (1D &2D) for subwavelength photon operation purposes. The fundamental task involves a search for available semiconductor materials as micro-nano light sources and optical interconnections; in this regard, finding a white-light source is the most challenging task because typical band-band emission is not possible in the single phase. Using current approaches, which rely on surface-state emission and the integration of various emission components, it is impossible to achieve single-phase, single-unit components with specific space dimensions. Here, we achieved continuous full-color (ultraviolet to red) emission by engineering a single Al4O4C nanowire with Si doping, which created impurity levels in the bandgap and conduction band. High light propagation performance was also observed when blue, green and red lasers were coupled into a single nanowire using a tapered optical fiber. This novel 1D nanostructure is an excellent candidate for use in future photonic circuits as a white-light source or interconnection component.
- Published
- 2014
- Full Text
- View/download PDF
41. Endothelial deletion of Sag/Rbx2/Roc2 E3 ubiquitin ligase causes embryonic lethality and blocks tumor angiogenesis.
- Author
-
Tan M, Li H, and Sun Y
- Subjects
- Animals, Carrier Proteins metabolism, Cell Movement genetics, Cell Proliferation genetics, Cyclin-Dependent Kinase Inhibitor p27 genetics, Cyclin-Dependent Kinase Inhibitor p27 metabolism, Cyclopentanes pharmacology, Endothelial Cells pathology, Gene Deletion, Gene Knockdown Techniques, Melanoma, Experimental drug therapy, Melanoma, Experimental pathology, Mice, Knockout, NEDD8 Protein, Pyrimidines pharmacology, Ubiquitin-Protein Ligases metabolism, Ubiquitins antagonists & inhibitors, Ubiquitins metabolism, Carrier Proteins genetics, Embryo Loss genetics, Neovascularization, Pathologic genetics
- Abstract
SAG (Sensitive to Apoptosis Gene), also known as RBX2 or ROC2, is a RING protein required for the activity of Cullin-RING ligase (CRL). Our recent study showed that Sag total knockout caused embryonic lethality at E11.5-12.5 days with associated defects in vasculogenesis. Whether Sag is required for de novo vasculogenesis in embryos and angiogenesis in tumors is totally unknown. Here, we report that Sag endothelial deletion also causes embryonic lethality at E15.5 with poor vasculogenesis. Sag deletion in primary endothelial cells (ECs) or knockdown in MS-1 ECs inhibits migration, proliferation and tube formation, with p27 accumulation being responsible for the suppression of migration and proliferation. Furthermore, Sag deletion significantly inhibits angiogenesis in an in vivo Matrigel plug assay, and tumor angiogenesis and tumorigenesis in a B16F10 melanoma model. Finally, MLN4924, an investigational small molecule inhibitor of NEDD8-activating enzyme (NAE) that inhibits CRL, suppresses in vitro migration, proliferation and tube formation, as well as in vivo angiogenesis and tumorigenesis. Taken together, our study, using both genetic and pharmaceutical approaches, demonstrates that Sag is essential for embryonic vasculogenesis and tumor angiogenesis, and provides the proof-of-concept evidence that targeting Sag E3 ubiquitin ligase may have clinical value for anti-angiogenesis therapy of human cancer.
- Published
- 2014
- Full Text
- View/download PDF
42. miR-508-5p regulates multidrug resistance of gastric cancer by targeting ABCB1 and ZNRD1.
- Author
-
Shang Y, Zhang Z, Liu Z, Feng B, Ren G, Li K, Zhou L, Sun Y, Li M, Zhou J, An Y, Wu K, Nie Y, and Fan D
- Subjects
- 3' Untranslated Regions, ATP Binding Cassette Transporter, Subfamily B, ATP Binding Cassette Transporter, Subfamily B, Member 1 metabolism, Animals, Cell Line, Tumor, Cisplatin pharmacology, DNA-Binding Proteins metabolism, Doxorubicin pharmacology, Drug Resistance, Multiple, Drug Screening Assays, Antitumor, Fluorouracil pharmacology, Gene Expression Regulation, Neoplastic drug effects, Humans, Mice, Mice, Nude, MicroRNAs biosynthesis, RNA, Messenger genetics, Stomach Neoplasms metabolism, Transfection, Vincristine pharmacology, Xenograft Model Antitumor Assays, ATP Binding Cassette Transporter, Subfamily B, Member 1 genetics, Antineoplastic Agents pharmacology, DNA-Binding Proteins genetics, MicroRNAs genetics, Stomach Neoplasms drug therapy, Stomach Neoplasms genetics
- Abstract
Multidrug resistance (MDR) is usually correlated with the poor prognosis of gastric cancer. In this study, we revealed a total of 11 microRNAs (miRNA) that regulated MDR of gastric cancer via high-throughput functional screening, and miR-508-5p reversed MDR most efficiently among these candidate miRNAs. The overexpression of miR-508-5p was sufficient to reverse cancer cell resistance to multiple chemotherapeutics in vitro and sensitize tumours to chemotherapy in vivo. Further studies showed that miR-508-5p could directly target the 3'-untranslated regions of ABCB1 and Zinc ribbon domain-containing 1 (ZNRD1), and suppress their expression at the mRNA and protein levels. Meanwhile, the suppression of ZNRD1 led to a decrease in ABCB1. These findings suggest that a miR-508-5p/ZNRD1/ABCB1 regulatory loop has a critical role in MDR in gastric cancer. In addition, miR-508-5p could be used as a prognostic factor for overall survival in gastric cancer. These data reveal an important role for miR-508-5p in the regulation of MDR in gastric cancer, and suggest the potential application of miR-508-5p in drug resistance prediction and treatment.
- Published
- 2014
- Full Text
- View/download PDF
43. Histone deacetylase 5 blocks neuroblastoma cell differentiation by interacting with N-Myc.
- Author
-
Sun Y, Liu PY, Scarlett CJ, Malyukova A, Liu B, Marshall GM, MacKenzie KL, Biankin AV, and Liu T
- Subjects
- Cell Differentiation genetics, Cell Differentiation physiology, Cell Line, Tumor, Cell Proliferation, Chromatin Immunoprecipitation, Gene Expression Profiling, Gene Expression Regulation, Neoplastic, Genome, Human, HEK293 Cells, Humans, N-Myc Proto-Oncogene Protein, Nedd4 Ubiquitin Protein Ligases, Neuroblastoma genetics, Neuroblastoma pathology, Aurora Kinase A metabolism, Endosomal Sorting Complexes Required for Transport metabolism, Histone Deacetylases metabolism, Neuroblastoma metabolism, Nuclear Proteins metabolism, Oncogene Proteins metabolism, Sirtuin 2 metabolism, Ubiquitin-Protein Ligases metabolism
- Abstract
The N-Myc oncoprotein induces neuroblastoma, which arises from undifferentiated neuroblasts in the sympathetic nervous system, by modulating gene and protein expression and consequently causing cell differentiation block and cell proliferation. The class IIa histone deacetylase 5 (HDAC5) represses gene transcription, and blocks myoblast, osteoblast and leukemia cell differentiation. Here we showed that N-Myc upregulated HDAC5 expression in neuroblastoma cells. Conversely, HDAC5 repressed the ubiquitin-protein ligase NEDD4 gene expression, increased Aurora A gene expression and consequently upregulated N-Myc protein expression. Genome-wide gene expression analysis and protein co-immunoprecipitation assays revealed that HDAC5 and N-Myc repressed the expression of a common subset of genes by forming a protein complex, whereas HDAC5 and the class III HDAC SIRT2 independently repressed the expression of another common subset of genes without forming a protein complex. Moreover, HDAC5 blocked differentiation and induced proliferation in neuroblastoma cells. Taken together, our data identify HDAC5 as a novel co-factor in N-Myc oncogenesis, and provide the evidence for the potential application of HDAC5 inhibitors in the therapy of N-Myc-induced neuroblastoma and potentially other c-Myc-induced malignancies.
- Published
- 2014
- Full Text
- View/download PDF
44. Association between body fat distribution and androgen deficiency in middle-aged and elderly men in China.
- Author
-
Ren Y, Wang B, Liu X, Li Z, Yuan W, Sun Y, and Miao M
- Subjects
- Adult, Aged, Body Height, Body Mass Index, China, Cross-Sectional Studies, Humans, Logistic Models, Male, Middle Aged, Obesity complications, Obesity, Abdominal complications, Odds Ratio, Risk Factors, Waist Circumference, Body Fat Distribution, Testosterone blood, Testosterone deficiency
- Abstract
The objective of the present study was to examine the association between body fat distribution and total testosterone (TT) and free testosterone (FT) levels among middle-aged and elderly men. A total of 922 male residents aged 40-70 years from a community in Shanghai, China, participated in the study. Their waist circumference (WC), waist-height ratio (WHtR), body mass index (BMI), and TT and FT concentrations were measured. Logistic regression models were used to estimate testosterone deficiency risk on the basis of anthropometric indices. BMI, WC and WHtR were all associated with TT deficiency. The participants in the highest quartiles of above-mentioned anthropometric indices had the highest risk of TT deficiency (BMI: odds ratio (OR)=4.40, 95% confidence interval (CI)=2.69-7.19; WC: OR=3.47, 95% CI=2.14-5.60; WHtR: OR=2.89, 95% CI=1.76-4.76). WC and WHtR were associated with FT deficiency. The participants in the highest quartiles had the highest risk of FT deficiency (WC: OR=1.87, 95% CI=1.18-2.97; WHtR: OR=1.67, 95% CI=1.04-2.66). The association between BMI and FT deficiency was not statistically significant (OR=1.21 for the highest quartile, 95% CI=0.78-1.87). Our study demonstrated that both general and abdominal obesity were associated with TT deficiency, whereas only abdominal obesity was found to be associated with FT deficiency.
- Published
- 2014
- Full Text
- View/download PDF
45. PPARγ maintains ERBB2-positive breast cancer stem cells.
- Author
-
Wang X, Sun Y, Wong J, and Conklin DS
- Subjects
- Acetylcysteine pharmacology, Anilides pharmacology, Animals, Benzamides pharmacology, Breast Neoplasms metabolism, Cell Line, Tumor, Female, Humans, Kruppel-Like Factor 4, MCF-7 Cells, Mediator Complex Subunit 1 metabolism, Mice, Mice, Inbred NOD, Mice, SCID, Neoplasm Transplantation, Neoplastic Stem Cells metabolism, Nuclear Receptor Subfamily 1, Group D, Member 1 metabolism, PPAR gamma antagonists & inhibitors, Pyridines pharmacology, Reactive Oxygen Species, Aldehyde Dehydrogenase metabolism, Breast Neoplasms pathology, Neoplastic Stem Cells pathology, PPAR gamma metabolism, Receptor, ErbB-2 metabolism
- Abstract
Overexpression of the adverse prognostic marker ERBB2 occurs in 30% of breast cancers and is associated with aggressive disease and poor outcomes. Our recent findings have shown that NR1D1 and the peroxisome proliferator-activated receptor-γ (PPARγ)-binding protein (PBP) act through a common pathway in upregulating several genes in the de novo fatty acid synthesis network, which is highly active in ERBB2-positive breast cancer cells. NR1D1 and PBP are functionally related to PPARγ, a well-established positive regulator of adipogenesis and lipid storage. Here, we report that inhibition of the PPARγ pathway reduces the aldehyde dehydrogenase (ALDH)-positive population in ERBB2-positive breast cancer cells. Results from in vitro tumorsphere formation assays demonstrate that the PPARγ antagonists GW9662 and T0070907 decrease tumorsphere formation in ERBB2-positive cells, but not other breast cells. We show that the mechanism by which GW9662 treatment causes a reduction in ALDH-positive population cells is partially due to ROS, as it can be rescued by treatment with N-acetyl-cysteine. Furthermore, global gene expression analyses show that GW9662 treatment suppresses the expression of several lipogenic genes, including ACLY, MIG12, FASN and NR1D1, and the stem-cell related genes KLF4 and ALDH in BT474 cells. Antagonist treatment also decreases the level of acetylation in histone 3 and histone 4 in BT474 cells, compared with MCF7 cells. In vivo, GW9662 pre-treatment inhibits the tumor-seeding ability of BT474 cells. Together, these results show that the PPARγ pathway is critical for the cancer stem cell properties of ERBB2-positive breast cancer cells.
- Published
- 2013
- Full Text
- View/download PDF
46. Elevated cell proliferation and VEGF production by high-glucose conditions in Müller cells involve XIAP.
- Author
-
Sun Y, Wang D, Ye F, Hu DN, Liu X, Zhang L, Gao L, Song E, and Zhang DY
- Subjects
- Analysis of Variance, Animals, Benzoquinones pharmacology, Blotting, Western, Cells, Cultured, Ependymoglial Cells cytology, Ependymoglial Cells metabolism, Rats, Rats, Sprague-Dawley, Cell Proliferation drug effects, Ependymoglial Cells drug effects, Glucose pharmacology, Vascular Endothelial Growth Factor A metabolism, X-Linked Inhibitor of Apoptosis Protein pharmacology
- Abstract
Purpose: Müller cells have important roles in the pathogenesis of diabetic retinopathy by promoting cell proliferation and inducing the production of vascular endothelial growth factor (VEGF) under hyperglycemic conditions. The objective of this study was to determine the potential mechanism of Müller cell proliferation and VEGF production due to high-glucose conditions., Methods: Primary cultured rat Müller cells were incubated with medium containing variable concentrations of glucose and/or embelin, a specific inhibitor of X-linked inhibitor of apoptosis protein (XIAP), for 72 h. The proliferation of Müller cells was assessed by the MTT assay. The expression and/or phosphorylation of 146 proteins were assessed using protein pathway array., Results: High concentrations of glucose-induced Müller cell proliferation and altered expression and/or phosphorylation of 47 proteins that have been identified to have key roles in several important signaling pathways (XIAP, VEGF, HIF1α, NFκB, etc) and are involved in the regulation of cell survival, proliferation, or apoptosis. However, Müller cell alterations induced by high-glucose conditions were counteracted by the XIAP inhibitor embelin, and 26 proteins/phosphorylations (out of 47) were restored to their normal levels. Nine proteins, including NFκB p65, p-p38, tumor necrosis factor-α, urokinase-type plasminogen activator, CREB, IL-1β, HCAM, estrogen receptor-α, and p-Stat3, were involved in regulatory networks between XIAP and VEGF., Conclusions: The current study suggests that XIAP may be a potential regulator that can mediate a series of pathological changes induced by high-glucose conditions in Müller cells. Therefore, embelin could be a potential agent for the prevention and treatment of diabetic retinopathy.
- Published
- 2013
- Full Text
- View/download PDF
47. Infrared evidence of a Slater metal-insulator transition in NaOsO₃.
- Author
-
Vecchio IL, Perucchi A, Di Pietro P, Limaj O, Schade U, Sun Y, Arai M, Yamaura K, and Lupi S
- Abstract
The magnetically driven metal-insulator transition (MIT) was predicted by Slater in the fifties. Here a long-range antiferromagnetic (AF) order can open up a gap at the Brillouin electronic band boundary regardless of the Coulomb repulsion magnitude. However, while many low-dimensional organic conductors display evidence for an AF driven MIT, in three-dimensional (3D) systems the Slater MIT still remains elusive. We employ terahertz and infrared spectroscopy to investigate the MIT in the NaOsO₃ 3D antiferromagnet. From the optical conductivity analysis we find evidence for a continuous opening of the energy gap, whose temperature dependence can be well described in terms of a second order phase transition. The comparison between the experimental Drude spectral weight and the one calculated through Local Density Approximation (LDA) shows that electronic correlations play a limited role in the MIT. All the experimental evidence demonstrates that NaOsO₃ is the first known 3D Slater insulator.
- Published
- 2013
- Full Text
- View/download PDF
48. Every 36-h gentamicin dosing in neonates with hypoxic-ischemic encephalopathy receiving hypothermia.
- Author
-
Frymoyer A, Lee S, Bonifacio SL, Meng L, Lucas SS, Guglielmo BJ, Sun Y, and Verotta D
- Subjects
- Anti-Bacterial Agents blood, Female, Gentamicins blood, Gestational Age, Humans, Infant, Newborn, Male, Retrospective Studies, Anti-Bacterial Agents administration & dosage, Anti-Bacterial Agents pharmacokinetics, Gentamicins administration & dosage, Gentamicins pharmacokinetics, Hypothermia, Induced, Hypoxia-Ischemia, Brain therapy
- Abstract
Objective: To examine the impact of a change in the empiric gentamicin dose from 5 mg kg(-1) every 24 h (Q24 h period) to 5 mg kg every 36 h (Q36 h period) on target drug concentration achievement in neonates with hypoxic ischemic encephalopathy (HIE) receiving therapeutic hypothermia., Study Design: Gentamicin drug concentrations in neonates with HIE receiving therapeutic hypothermia were examined during two time periods in a retrospective chart review. During the initial treatment period (November 2007 to March 2010; n=29), neonates received Q24 h period. During the second treatment period (January 2011 to May 2012; n=23), the dose was changed to Q36 h period. Cooling criteria and protocol remained the same between treatment periods. Gentamicin drug concentrations including achievement of target trough concentrations (<2 mg l(-1)) were compared between treatment periods. Individual Bayesian estimates of gentamicin clearance were also compared., Result: Neonates with an elevated trough concentration >2 mg l(-1) decreased from 38 to 4% with implementation of a Q36-h dosing interval (P<0.007). The mean gentamicin trough concentration was 2.0 ± 0.8 mg l(-1) during the Q24 h period and 0.9 ± 0.4 mg l(-1) during the Q36 h period (P<0.001). Peak concentrations were minimally impacted (Q24 h 11.4 ± 2.3 mg l(-1) vs Q36 h 10.0 ± 1.9 mg l(-1); P=0.05). The change in gentamicin trough concentration could not be accounted for by differences in gentamicin clearance between treatment periods (P=0.9)., Conclusion: A 5 mg kg(-1) every 36-h gentamicin dosing strategy in neonates with HIE receiving therapeutic hypothermia improved achievement of target trough concentration <2 mg l(-1), while still providing high peak concentration exposure.
- Published
- 2013
- Full Text
- View/download PDF
49. Basic anatomy and tumor biology of the RPS6KA6 gene that encodes the p90 ribosomal S6 kinase-4.
- Author
-
Sun Y, Cao S, Yang M, Wu S, Wang Z, Lin X, Song X, and Liao DJ
- Subjects
- Animals, Antimetabolites, Antineoplastic pharmacology, Apoptosis, Azacitidine pharmacology, Base Sequence, Blotting, Western, Cell Adhesion, Cell Cycle, Cell Proliferation, Cyclin D1 genetics, Cyclin D1 metabolism, DNA, Complementary genetics, Female, Humans, Immunoenzyme Techniques, Immunoprecipitation, Mice, Mice, SCID, Molecular Sequence Data, Neoplasms drug therapy, Neoplasms genetics, Protein Isoforms, Proto-Oncogene Proteins c-myc genetics, Proto-Oncogene Proteins c-myc metabolism, RNA, Messenger genetics, RNA, Small Interfering genetics, Real-Time Polymerase Chain Reaction, Reverse Transcriptase Polymerase Chain Reaction, Ribosomal Protein S6 Kinases, 90-kDa antagonists & inhibitors, Ribosomal Protein S6 Kinases, 90-kDa genetics, Sequence Homology, Nucleic Acid, Transcription Initiation Site, Tumor Cells, Cultured, Alternative Splicing, Antineoplastic Agents pharmacology, Exons genetics, Neoplasms pathology, Ribosomal Protein S6 Kinases, 90-kDa metabolism
- Abstract
The RPS6KA6 gene encodes the p90 ribosomal S6 kinase-4 (RSK4) that is still largely uncharacterized. In this study we identified a new RSK4 transcription initiation site and several alternative splice sites with a 5'-RACE approach. The resulting mRNA variants encompass four possible first start codons. The first 15 nucleotides (nt) of exon 22 in mouse and the penultimate exon in both human (exon 21) and mouse (exon 24) RSK4 underwent alternative splicing, although the penultimate exon deleted variant appeared mainly in cell clines, but not in most normal tissues. Demethylation agent 5-azacytidine inhibited the deletion of the penultimate exon, whereas two indolocarbazole-derived inhibitors of cyclin-dependent kinase 4 or 6 induced deletion of the first 39 nt from exon 21 of human RSK4. In all human cancer cell lines studied, the 90-kDa wild-type RSK4 was sparse but, surprisingly, several isoforms at or smaller than 72 kDa were expressed as detected by seven different antibodies. On immunoblots, each of these smaller isoforms often appeared as a duplet or triplet and the levels of these isoforms varied greatly among different cell lines and culture conditions. Cyclin D1 inhibited RSK4 expression and serum starvation enhanced the inhibition, whereas c-Myc and RSK4 inhibited cyclin D1. The effects of RSK4 on cell growth, cell death and chemoresponse depended on the mRNA variant or the protein isoform expressed, on the specificity of the cell lines, as well as on the anchorage-dependent or -independent growth conditions and the in vivo situation. Moreover, we also observed that even a given cDNA might be expressed to multiple proteins; therefore, when using a cDNA, one needs to exclude this possibility before attribution of the biological results from the cDNA to the anticipated protein. Collectively, our results suggest that whether RSK4 is oncogenic or tumor suppressive depends on many factors.
- Published
- 2013
- Full Text
- View/download PDF
50. Induction of autophagy and senescence by knockdown of ROC1 E3 ubiquitin ligase to suppress the growth of liver cancer cells.
- Author
-
Yang D, Li L, Liu H, Wu L, Luo Z, Li H, Zheng S, Gao H, Chu Y, Sun Y, Liu J, and Jia L
- Subjects
- Carcinoma, Hepatocellular metabolism, Carrier Proteins antagonists & inhibitors, Carrier Proteins genetics, Cell Line, Tumor, Cell Proliferation, Cyclin-Dependent Kinase Inhibitor p21 metabolism, G2 Phase Cell Cycle Checkpoints, Hep G2 Cells, Humans, Intracellular Signaling Peptides and Proteins, Liver Neoplasms metabolism, M Phase Cell Cycle Checkpoints, RNA Interference, RNA, Small Interfering metabolism, Survival Rate, TOR Serine-Threonine Kinases metabolism, Autophagy, Carcinoma, Hepatocellular pathology, Carrier Proteins metabolism, Cellular Senescence, Liver Neoplasms pathology
- Abstract
Regulator of Cullins-1 (ROC1) or RING box protein-1 (RBX1) is an essential RING component of Cullin-RING ligase (CRL). Our previous studies showed that ROC1 is required for the growth of several cancer cell lines while ROC1 siRNA silencing inactivates CRL, leading to cell cycle arrest, cell senescence and/or apoptosis. However, it is completely unknown whether ROC1 knockdown triggers autophagic response by inactivating CRL. Moreover, the role of ROC1 in liver cancer remains elusive. In this study, we reported that ROC1 knockdown significantly inhibited the growth of liver cancer cells by sequentially and independently inducing autophagy and p21-dependent cell senescence. Mechanism analysis revealed that ROC1 silencing triggered autophagy by inhibition of mammalian target of rapamycin (mTOR) activity due to accumulation of mTOR-inhibitory protein Deptor, a substrate of CRL. Consistently, Deptor knockdown significantly blocked autophagy response upon ROC1 silencing. Biologically, autophagy response upon ROC1 silencing was a survival signal, and blockage of autophagy pathway sensitized cancer cells to apoptosis. Finally, we demonstrated that ROC1 was overexpressed in hepatocellular carcinomas, which is associated with poor prognosis of liver cancer patients. These findings suggest that ROC1 is an appealing drug target for liver cancer and provide a proof-of-concept evidence for a novel drug combination of ROC1 inhibitor and an autophagy inhibitor for effective treatment of liver cancer by enhancing apoptosis.
- Published
- 2013
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.