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1.
Clin Oral Investig ; 28(2): 146, 2024 Feb 13.
Article in English | MEDLINE | ID: mdl-38351210

ABSTRACT

OBJECTIVES: Trismus, marked by restricted mouth opening, significantly affects patients with temporomandibular disorder (TMD) and head and neck cancer (HNC). Despite its prevalence, specialized questionnaires for trismus assessment are scarce. This study aims to fill this gap by translating and validating the Gothenburg Trismus Questionnaire version 2 (GTQ-2) into Chinese (C-GTQ-2), enhancing the evaluation of trismus in HNC and TMD patients. MATERIALS AND METHODS: The study involved 78 HNC patients, 75 TMD patients, and a control group of 150 individuals without trismus symptoms. Participants were asked to complete the C-GTQ-2 and other health-related quality of life (HRQL) instruments. A subset of 30 individuals retook the questionnaire within two weeks to assess test-retest reliability. RESULTS: The C-GTQ-2 demonstrated remarkable reliability, with Cronbach's alpha values exceeding 0.70 in three of the four domains, indicating high internal consistency. The instrument also showcased high intra-class correlations in the test-retest, affirming its reliability. Furthermore, it exhibited strong convergent validity, aligning well with other HRQL instruments, and effectively discriminated between patients with and without trismus, establishing its discriminant validity. CONCLUSIONS: The C-GTQ-2 emerges as a valid and reliable tool for assessing trismus in HNC and TMD patients, promising to significantly enhance both clinical and research approaches to managing trismus-related complications in the Chinese-speaking demographic. CLINICAL RELEVANCE: C-GTQ-2 proves effective for trismus assessment in head and neck cancer and temporomandibular disorder patients, offering enhanced clinical and research utility.


Subject(s)
Head and Neck Neoplasms , Temporomandibular Joint Disorders , Humans , Trismus/diagnosis , Trismus/etiology , Quality of Life , Reproducibility of Results , Head and Neck Neoplasms/complications , Temporomandibular Joint Disorders/complications , Surveys and Questionnaires , Psychometrics
2.
Front Med (Lausanne) ; 9: 889125, 2022.
Article in English | MEDLINE | ID: mdl-35795629

ABSTRACT

Chemotherapy agents are cytotoxic materials. Thus, there is a need for the operators to be familiar with the knowledge and procedures before operation. We conducted a randomized controlled trial investigating the effectiveness of an immersive 3D VR teaching of chemotherapy administration operated in a smartphone coupled with a visual and audio device. We adopted a two-arm single-blind design and recruited 83 nurses, and they were randomized using a cluster approach. The VR group learned chemotherapy administration through VR, while the controlled group learned through document reading. The Knowledge and Attitude of Chemotherapy Administration (KACA) was administrated before the intervention, while the Objective Structured Clinical Examination (OSCE) and the Checklist of Action Accomplishment (CAA) were administrated one month after the intervention. The VR group scored higher than the controlled group in the CAA (95.69 ± 5.37 vs. 91.98 ± 9.31, p = 0.02) and the OSCE (73.07 ± 10.99 vs. 67.44 ±10.65, p = 0.02). Stepwise regression demonstrated that service years, an education level of undergraduate or above, and VR exposure contributed positively to the OSCE score (adjusted R2 = 0.194, p = 0.028). The use of VR improves the learning efficacy of chemotherapy administration in non-oncology nurses. We recommend using VR as a teaching tool for chemotherapy administration and other chemotherapy-related skills in a VR learning group with senior nurses with higher education levels as advisors. The study provides an approach to online training, especially during the COVID-19 pandemic. (CONSORT 2010 guidelines, registry number: NCT04840732).

3.
J Dent Sci ; 17(1): 331-337, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35028055

ABSTRACT

BACKGROUND/PURPOSE: Previously we demonstrated up-regulation of matrix metalloproteinase-3 (MMP-3) in human osteoblasts under compression and in bony specimens of experimental orthodontic tooth movement (OTM). Here, we studied the temporal characteristics of compression stimulation in human and mouse osteoblast cell lines, and generated a transgenic mouse model for assessing the MMP-3 expression during OTM. MATERIALS AND METHODS: We investigated MMP-3 expressions in human and murine osteoblasts through RT-PCR and luciferase assay, after compressive force loading. Inhibitors were added to identify the possible mechanisms for signal transduction. A human MMP-3 promoter was isolated, cloned and transfected to generate a transgenic mouse with a green fluorescent protein reporter. OTM was then initiated to observe the location and time course of transcriptional regulation of MMP-3 signals. RESULTS: We found changes in the transcription of MMP-3 in response to mechanical force applied to both human and mouse osteoblast cell lines, suggesting that the response is positive across species. Cloned human MMP-3 promoter may cause the response of luciferase to 1% compression. Moreover, p38 inhibitor exerted a down-regulatory effect on MMP-3 promoter expression, although the inhibitory effect didn't reach a significant level. In the transgenic mouse OTM model, we again found increased expression of MMP-3 in response to mechanical force loading around the periodontal ligament. CONCLUSION: Mechanical force can stimulate MMP-3 expression, possibly through the p38 MAPK pathway, with its strongest signal occurring at 24 h. The mechanical responsiveness in MMP-3 promoter regions can be observed in both humans and rodents in vitro and in vivo.

4.
Nat Commun ; 12(1): 3082, 2021 05 25.
Article in English | MEDLINE | ID: mdl-34035302

ABSTRACT

Splicing, a key step in the eukaryotic gene-expression pathway, converts precursor messenger RNA (pre-mRNA) into mRNA by excising introns and ligating exons. This task is accomplished by the spliceosome, a macromolecular machine that must undergo sequential conformational changes to establish its active site. Each of these major changes requires a dedicated DExD/H-box ATPase, but how these enzymes are activated remain obscure. Here we show that Prp28, a yeast DEAD-box ATPase, transiently interacts with the conserved 5' splice-site (5'SS) GU dinucleotide and makes splicing-dependent contacts with the U1 snRNP protein U1C, and U4/U6.U5 tri-snRNP proteins, Prp8, Brr2, and Snu114. We further show that Prp28's ATPase activity is potentiated by the phosphorylated Npl3, but not the unphosphorylated Npl3, thus suggesting a strategy for regulating DExD/H-box ATPases. We propose that Npl3 is a functional counterpart of the metazoan-specific Prp28 N-terminal region, which can be phosphorylated and serves as an anchor to human spliceosome.


Subject(s)
DEAD-box RNA Helicases/metabolism , Nuclear Proteins/metabolism , RNA Splicing , RNA-Binding Proteins/metabolism , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae/metabolism , Spliceosomes/metabolism , Adenosine Triphosphate/metabolism , DEAD-box RNA Helicases/genetics , Humans , Multiprotein Complexes/genetics , Multiprotein Complexes/metabolism , Mutation , Nuclear Proteins/genetics , Phosphorylation , Protein Binding , RNA Helicases/genetics , RNA Helicases/metabolism , RNA Precursors/genetics , RNA Precursors/metabolism , RNA-Binding Proteins/genetics , Ribonuclease H/metabolism , Ribonucleoproteins, Small Nuclear/metabolism , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae Proteins/genetics , Spliceosomes/genetics
5.
Mediators Inflamm ; 2019: 8029863, 2019.
Article in English | MEDLINE | ID: mdl-31015798

ABSTRACT

Ankylosing spondylitis (AS) is a chronic inflammatory disease that leads to spinal ankylosis. The receptor activator of the nuclear factor-kappa (RANK), RANK ligand, and osteoprotegerin (OPG) (RANK/RANKL/OPG) pathway plays critical roles in bone metabolism and the immune system. The current study was aimed at investigating whether six single-nucleotide polymorphisms (SNPs) within the RANK, RANKL, and OPG genes essential for bone homeostasis are associated with AS. Genotype distributions, allele and haplotype frequencies, were compared between 1120 AS patients and 1435 healthy controls and among AS patients with stratification by syndesmophyte formation, onset age, and HLA-B27 positivity. We found that RANKL SNPs were associated with AS syndesmophyte formation. Notably, the RANKL SNP haplotype rs7984870C/rs9533155G/rs9525641C was negatively associated with AS susceptibility and appeared to protect against syndesmophyte formation in AS. Functionally, RANKL promoter SNPs (rs9525641 C/T and rs9533155 G/C) affected DNA-protein complex formation and promoter activity in promoter reporter analyses. The OPG SNP haplotype rs2073618G/rs3102735T was significantly associated with HLA-B27 negativity in AS patients. Furthermore, AS patients with syndesmophyte formation had significantly lower levels of soluble RANKL levels than those without syndesmophyte formation. Our data suggested a role for RANKL in AS susceptibility and severity.


Subject(s)
Osteoprotegerin/genetics , RANK Ligand/genetics , Receptor Activator of Nuclear Factor-kappa B/genetics , Spondylitis, Ankylosing/genetics , Adolescent , Adult , Enzyme-Linked Immunosorbent Assay , Female , Genetic Predisposition to Disease/genetics , Genotype , HLA-B27 Antigen/metabolism , Humans , Male , Middle Aged , Mutagenesis, Site-Directed , Polymorphism, Single Nucleotide/genetics , Young Adult
6.
Mol Carcinog ; 56(9): 2035-2047, 2017 09.
Article in English | MEDLINE | ID: mdl-28383782

ABSTRACT

Accumulating evidence suggests that human hepatocellular carcinoma (HCC) can be derived from cancer stem cells (CSCs), which contribute to tumor initiation, metastasis, chemoresistance, and recurrence. A great variety of HCC CSCs resulting in diverse clinical manifestations have been reported. However, how CSC diversity is regulated and generated remains unclear. Here we report that the miR-200b-ZEB1 circuit is closely involved with the induction and maintenance of a diverse group of CSCs. We found that miR-200b downregulation occurred in early HCC and associated with poor prognosis. The downregulation was attributable to genome deletion and promoter methylation of the miR-200a/b/429 gene. Ectopic expression of miR-200b or silencing of ZEB1 led to a decrease in CD13+ and CD24+ HCC CSCs and an increase in EpCAM+ HCC CSCs. Mechanistically, miR-200b directly suppressed BMI1 and ZEB1 expressions. ZEB1 recognized promoters of CD13, CD24, and EpCAM genes resulting in CD13 and CD24 upregulation and EpCAM downregulation. Neither miR-200b nor ZEB1 had obvious effects on CD133 or CD90 expression. Silencing CD13 or CD24 expression suppressed tumorigenicity of HCC cells. Ectopic expression of CD24 reversed the suppression of tumorigenicity by ectopic expression of miR-200b. Clinically, miR-200b downregulation was coupled with ZEB1 upregulation in approximately two-thirds of HCC patients. ZEB1 expression was positively correlated with CD13 and CD24 expressions in HCCs, while miR-200b expression was positively correlated with EpCAM. Our findings suggest that the miR-200b-ZEB1 circuit is a master regulator of diverse stemness of HCC, which differentiates HCCs into those containing CD13+ /CD24+ CSCs from those containing EpCAM+ CSCs.


Subject(s)
Carcinoma, Hepatocellular/metabolism , MicroRNAs/metabolism , Neoplastic Stem Cells/metabolism , Zinc Finger E-box-Binding Homeobox 1/metabolism , Antigens, Differentiation/metabolism , CD13 Antigens/metabolism , CD24 Antigen/metabolism , Carcinoma, Hepatocellular/genetics , Cell Differentiation , Cell Line, Tumor , Cell Transformation, Neoplastic , DNA Methylation , DNA, Neoplasm/metabolism , Down-Regulation , Gene Deletion , Gene Expression Regulation, Neoplastic , Humans , Neoplastic Stem Cells/microbiology , Promoter Regions, Genetic
7.
Clin Cancer Res ; 21(15): 3541-51, 2015 Aug 01.
Article in English | MEDLINE | ID: mdl-25840971

ABSTRACT

PURPOSE: Transcription factor RUNX1 is essential for normal hematopoiesis. High mutation frequencies of RUNX1 gene in chronic myelomonocytic leukemia (CMML) and myelodysplastic syndromes (MDS) have been described, whereas the biologic significances of the mutations were not investigated. Here, we aimed to correlate the biologic activities of the RUNX1 mutants with the clinical outcomes of patients. EXPERIMENTAL DESIGN: We examined the mutational status of RUNX1 in 143 MDS and 84 CMML patients. Then, we studied the DNA and CBFß binding abilities of all the RUNX1 mutants identified by using electrophoretic mobility shift assay and co-immunoprecipitation assay, and also determined their activities on target C-FMS gene induction by Western blotting and luciferase reporter assay. Using luciferase reporter assay, the relative biologic activities of each RUNX1 mutant could be quantified and correlated with the patient outcomes by statistical analyses. RESULTS: We observed that most RUNX1 mutants had reduced abilities in DNA binding, CBFß heterodimerization, and C-FMS gene induction. The relative biologic activities of RUNX1 mutants were grouped into high- and low-activity mutations. Correlation of the activities of RUNX1 mutants with the clinical outcomes revealed that patients harboring lower activities of RUNX1 mutants had a higher risk and shorter time to secondary acute myeloid leukemia transformation in MDS and CMML. In multivariate analysis, low RUNX1 activity remained an independent predictor for secondary acute myeloid leukemia-free survival in MDS patients. CONCLUSIONS: The biologic activity rather than the mutational status of RUNX1 might be an indicator in predicting outcome of patients with MDS and CMML.


Subject(s)
Cell Transformation, Neoplastic/genetics , Core Binding Factor Alpha 2 Subunit/genetics , Leukemia, Myelomonocytic, Chronic/genetics , Myelodysplastic Syndromes/genetics , Cell Transformation, Neoplastic/pathology , Core Binding Factor beta Subunit/genetics , Core Binding Factor beta Subunit/metabolism , DNA Mutational Analysis , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Disease Progression , Female , Gene Expression Regulation, Leukemic/genetics , HEK293 Cells , Humans , Leukemia, Myelomonocytic, Chronic/pathology , Male , Mutation , Myelodysplastic Syndromes/pathology , Neoplasm Proteins/biosynthesis , Prognosis , Receptor, Macrophage Colony-Stimulating Factor/genetics
8.
Laryngoscope ; 125(7): E231-8, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25877996

ABSTRACT

OBJECTIVES: The aim of this study is to investigate the role of Caveolin-1 (Cav-1) in nasopharyngeal carcinoma (NPC) progression and correlated with clinical outcomes. METHODS: We used quantitative real-time PCR (qPCR) to detect the difference in the expression of mRNA level of Cav-1 mRNA in NPC, non-NPC cell lines, and 74 NPC and 29 nontumorous nasopharyngeal mucosa biopsies. Western blotting and immunohistochemistry staining were used to detect the protein expression of Cav-1 in cell lines and biopsy tissues. We collected clinical follow-up data to investigate the association with expression of Cav-1 mRNA. Also, transfection of Cav-1 and suppression by delivery of shRNA against Cav-1 into NPC derived cell lines to analyze its influence in Akt signaling. RESULTS: By use of qPCR, immunohistochemical staining, and western blotting, we found that not only is Cav-1 overexpressed in human NPC tumor cells and NPC-derived cell lines but high Cav-1 mRNA expression is associated with poor overall survival time of NPC patients. Furthermore, phosphorylated Akt expression was enhanced by Cav-1 transfection and suppressed by delivery of shRNA against Cav-1. These data suggested a possible regulatory mechanism of Cav-1 on Akt signaling pathway. We also transfected the Cav-1 construct and shRNA in TW01 cells to prove the effect on Akt protein expression. CONCLUSIONS: Overexpression of Cav-1 is related to poor prognosis in NPC patients, which correlated with Akt signaling pathway. Abrogation of Akt signaling by shRNA-mediated knockdown of Cav-1 decreased malignant properties of tumor cells. These data suggest the potential for Cav-1 as a possible novel therapeutic target in NPC treatment.


Subject(s)
Caveolin 1/genetics , Gene Expression Regulation, Neoplastic/physiology , Nasopharyngeal Neoplasms/genetics , Oncogene Protein v-akt/genetics , Adolescent , Adult , Aged , Blotting, Western , Carcinoma , Cell Line, Tumor , Cell Movement , Female , Humans , Immunohistochemistry , Male , Middle Aged , Nasopharyngeal Carcinoma , Nasopharyngeal Neoplasms/diagnosis , Prognosis , RNA, Messenger/genetics , RNA, Small Interfering , Real-Time Polymerase Chain Reaction , Signal Transduction/genetics , Up-Regulation , Wound Healing , Young Adult
9.
J Virol ; 87(16): 9041-52, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23760235

ABSTRACT

Epstein-Barr virus (EBV) alters the regulation and expression of a variety of cytokines in its host cells to modulate host immune surveillance and facilitate viral persistence. Using cytokine antibody arrays, we found that, in addition to the cytokines reported previously, two chemotactic cytokines, CCL3 and CCL4, were induced in EBV-infected B cells and were expressed at high levels in all EBV-immortalized lymphoblastoid cell lines (LCLs). Furthermore, EBV latent membrane protein 1 (LMP1)-mediated Jun N-terminal protein kinase activation was responsible for upregulation of CCL3 and CCL4. Inhibition of CCL3 and CCL4 in LCLs using a short hairpin RNA approach or by neutralizing antibodies suppressed cell proliferation and caused apoptosis, indicating that autocrine CCL3 and CCL4 are required for LCL survival and growth. Importantly, significant amounts of CCL3 were detected in EBV-positive plasma from immunocompromised patients, suggesting that EBV modulates this chemokine in vivo. This study reveals the regulatory mechanism and a novel function of CCL3 and CCL4 in EBV-infected B cells. CCL3 might be useful as a therapeutic target in EBV-associated lymphoproliferative diseases and malignancies.


Subject(s)
B-Lymphocytes/virology , Cell Proliferation , Chemokine CCL3/biosynthesis , Chemokine CCL4/biosynthesis , Herpesvirus 4, Human/pathogenicity , Host-Pathogen Interactions , Viral Matrix Proteins/metabolism , B-Lymphocytes/metabolism , B-Lymphocytes/physiology , Humans , JNK Mitogen-Activated Protein Kinases/metabolism , Signal Transduction
10.
J Med Virol ; 84(8): 1279-88, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22711357

ABSTRACT

Epstein-Barr virus (EBV) belongs to the gammaherpesvirus family. To produce infectious progeny, EBV reactivates from latency into the lytic cycle by expressing the determinative lytic transactivator, Zta. In the presence of histone deacetylase inhibitor (HDACi), p53 is a prerequisite for the initiation of the EBV lytic cycle by facilitating the expression of Zta. In this study, a serial mutational analysis of Zta promoter (Zp) indicated an important role for the ZID element in responding to HDACi induction and p53 binds to this ZID element together with Sp1, a universal transcription factor. Abolition of the DNA-binding ability of Sp1 reduces the inducibility of ZID by HDACi and also reduces the amount of p53 binding to ZID. Finally, it was shown that EBV in p53-positive-lymphoblastoid cell lines (LCLs) can enter into the lytic cycle spontaneously; however, knockdown of p53 in LCLs leads to retardation of EBV reactivation.


Subject(s)
Gene Expression Regulation, Viral , Herpesvirus 4, Human/metabolism , Promoter Regions, Genetic/genetics , Sp1 Transcription Factor/metabolism , Trans-Activators/metabolism , Tumor Suppressor Protein p53/metabolism , Cell Line , DNA Mutational Analysis , Herpesvirus 4, Human/genetics , Humans , Sp1 Transcription Factor/genetics , Trans-Activators/genetics , Tumor Suppressor Protein p53/genetics , Virus Activation
11.
Virology ; 413(1): 19-25, 2011 Apr 25.
Article in English | MEDLINE | ID: mdl-21353277

ABSTRACT

The Epstein-Barr virus (EBV) infects and transforms primary B cells into lymphoblastoid cell lines (LCLs). We observed death-associated protein kinase 1 (DAPK1) upregulation in B cells following EBV infection and high DAPK1 levels in LCLs. DAPK1 participates in several apoptosis-inducing pathways, yet DAPK1 expression increased during B cell transformation. Data from LMP1 overexpression in LCLs and HeLa cells and from knocked down LMP1 in LCLs suggest LMP1 regulation of DAPK1 expression. We observed NF-κB signaling in DAPK1 upregulation by LMP1 with CTAR deletion mutants failing to induce DAPK1 expression and with Bay11 blocking DAPK1 expression. DAPK1 is inactive in LCLs due to insufficient stimuli, and is not regulated by Ser308 phosphorylation. However, DAPK1 in LCLs is functional, as evidenced by its quick mediation of cell death following UV or H(2)O(2) exposure, and increased survival among LCLs knocked down with DAPK. DAPK roles in EBV-infected B cells remain to be identified.


Subject(s)
Apoptosis Regulatory Proteins/metabolism , Calcium-Calmodulin-Dependent Protein Kinases/metabolism , Epstein-Barr Virus Infections/enzymology , Gene Expression Regulation, Enzymologic , Herpesvirus 4, Human/metabolism , Viral Matrix Proteins/metabolism , Apoptosis , Apoptosis Regulatory Proteins/genetics , B-Lymphocytes/cytology , B-Lymphocytes/enzymology , B-Lymphocytes/virology , Calcium-Calmodulin-Dependent Protein Kinases/genetics , Cell Line, Tumor , Death-Associated Protein Kinases , Epstein-Barr Virus Infections/physiopathology , Epstein-Barr Virus Infections/virology , Herpesvirus 4, Human/genetics , Humans , Viral Matrix Proteins/genetics
12.
J Virol ; 85(5): 2373-85, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21159880

ABSTRACT

Epstein-Barr virus (EBV) undergoes latent and lytic replication cycles, and its reactivation from latency to lytic replication is initiated by expression of the two viral immediate-early transactivators, Zta and Rta. In vitro, reactivation of EBV can be induced by anti-immunoglobulin, tetradecanoyl phorbol acetate, and histone deacetylase inhibitor (HDACi). We have discovered that protein kinase C delta (PKCδ) is required specifically for EBV reactivation by HDACi. Overexpression of PKCδ is sufficient to induce the activity of the Zta promoter (Zp) but not of the Rta promoter (Rp). Deletion analysis revealed that the ZID element of Zp is important for PKCδ activation. Moreover, the Sp1 putative sequence on ZID is essential for PKCδ-induced Zp activity, and the physiological binding of Sp1 on ZID has been confirmed. After HDACi treatment, activated PKCδ can phosphorylate Sp1 at serine residues and might result in dissociation of the HDAC2 repressor from ZID. HDACi-mediated HDAC2-Sp1 dissociation can be inhibited by the PKCδ inhibitor, Rotterlin. Furthermore, overexpression of HDAC2 can suppress the HDACi-induced Zp activity. Consequently, we hypothesize that HDACi induces PKCδ activation, causing phosphorylation of Sp1, and that the interplay between PKCδ and Sp1 results in the release of HDAC2 repressor from Zp and initiation of Zta expression.


Subject(s)
Epstein-Barr Virus Infections/metabolism , Herpesvirus 4, Human/physiology , Histone Deacetylase Inhibitors/pharmacology , Hydroxamic Acids/pharmacology , Protein Kinase C-delta/metabolism , Sp1 Transcription Factor/metabolism , Virus Activation/drug effects , Cell Line , Epstein-Barr Virus Infections/enzymology , Epstein-Barr Virus Infections/genetics , Epstein-Barr Virus Infections/virology , Gene Expression Regulation, Viral/drug effects , Herpesvirus 4, Human/drug effects , Herpesvirus 4, Human/genetics , Humans , Immediate-Early Proteins/genetics , Immediate-Early Proteins/metabolism , Phosphorylation/drug effects , Promoter Regions, Genetic/drug effects , Protein Binding/drug effects , Protein Kinase C-delta/genetics , Sp1 Transcription Factor/genetics , Trans-Activators/genetics , Trans-Activators/metabolism
13.
J Biol Chem ; 285(13): 10053-10063, 2010 Mar 26.
Article in English | MEDLINE | ID: mdl-20110360

ABSTRACT

Stathmin is an important microtubule (MT)-destabilizing protein, and its activity is differently attenuated by phosphorylation at one or more of its four phosphorylatable serine residues (Ser-16, Ser-25, Ser-38, and Ser-63). This phosphorylation of stathmin plays important roles in mitotic spindle formation. We observed increasing levels of phosphorylated stathmin in Epstein-Barr virus (EBV)-harboring lymphoblastoid cell lines (LCLs) and nasopharyngeal carcinoma (NPC) cell lines during the EBV lytic cycle. These suggest that EBV lytic products may be involved in the regulation of stathmin phosphorylation. BGLF4 is an EBV-encoded kinase and has similar kinase activity to cdc2, an important kinase that phosphorylates serine residues 25 and 38 of stathmin during mitosis. Using an siRNA approach, we demonstrated that BGLF4 contributes to the phosphorylation of stathmin in EBV-harboring NPC. Moreover, we confirmed that BGLF4 interacts with and phosphorylates stathmin using an in vitro kinase assay and an in vivo two-dimensional electrophoresis assay. Interestingly, unlike cdc2, BGLF4 was shown to phosphorylate non-proline directed serine residues of stathmin (Ser-16) and it mediated phosphorylation of stathmin predominantly at serines 16, 25, and 38, indicating that BGLF4 can down-regulate the activity of stathmin. Finally, we demonstrated that the pattern of MT organization was changed in BGLF4-expressing cells, possibly through phosphorylation of stathmin. In conclusion, we have shown that a viral Ser/Thr kinase can directly modulate the activity of stathmin and this contributes to alteration of cellular MT dynamics and then may modulate the associated cellular processes.


Subject(s)
Herpesvirus 4, Human/enzymology , Microtubules/metabolism , Protein Serine-Threonine Kinases/genetics , Protein Serine-Threonine Kinases/physiology , Stathmin/metabolism , Viral Proteins/genetics , Viral Proteins/physiology , Cell Line, Tumor , Down-Regulation , Electrophoresis, Gel, Two-Dimensional , Fluorescent Antibody Technique, Indirect , HeLa Cells , Humans , Leukocytes, Mononuclear/metabolism , Mitosis , Phosphorylation , Serine/chemistry , Transfection
14.
Blood ; 114(1): 109-18, 2009 Jul 02.
Article in English | MEDLINE | ID: mdl-19417211

ABSTRACT

Epstein-Barr virus (EBV) infection can modify the cytokine expression profiles of host cells and determine the fate of those cells. Of note, expression of interleukin-13 (IL-13) may be detected in EBV-associated Hodgkin lymphoma and the natural killer (NK) cells of chronic active EBV-infected patients, but its biologic role and regulatory mechanisms are not understood. Using cytokine antibody arrays, we found that IL-13 production is induced in B cells early during EBV infection. Furthermore, the EBV lytic protein, Zta (also known as the BZLF-1 product), which is a transcriptional activator, was found to induce IL-13 expression following transfection. Mechanistically, induction of IL-13 expression by Zta is mediated directly through its binding to the IL-13 promoter, via a consensus AP-1 binding site. Blockade of IL-13 by antibody neutralization showed that IL-13 is required at an early stage of EBV-induced proliferation and for long-term maintenance of the growth of EBV immortalized lymphoblastoid cell lines (LCLs). Thus, Zta-induced IL-13 production facilitates B-cell proliferation and may contribute to the pathogenesis of EBV-associated lymphoproliferative disorders, such as posttransplantation lymphoproliferative disease (PTLD) and Hodgkin lymphoma.


Subject(s)
B-Lymphocytes/pathology , B-Lymphocytes/virology , Herpesvirus 4, Human/immunology , Herpesvirus 4, Human/pathogenicity , Interleukin-13/biosynthesis , Trans-Activators/immunology , B-Lymphocytes/immunology , Base Sequence , Cell Line, Transformed , Cell Line, Tumor , Cell Proliferation , DNA Methylation , DNA Primers/genetics , DNA, Viral/genetics , Epstein-Barr Virus Infections/immunology , Epstein-Barr Virus Infections/pathology , Gene Expression , Herpesvirus 4, Human/genetics , Hodgkin Disease/etiology , Humans , Interleukin-13/genetics , Lymphocytes/immunology , Lymphocytes/pathology , Lymphocytes/virology , Lymphoproliferative Disorders/etiology , Promoter Regions, Genetic , Trans-Activators/genetics , Trans-Activators/physiology , Transcriptional Activation
15.
J Virol ; 82(15): 7745-51, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18495777

ABSTRACT

The tumor suppressor gene p53 plays a central role in the maintenance of normal cell growth and genetic integrity, while its impact on the Epstein-Barr virus (EBV) life cycle remains elusive. We found that p53 is important for histone deacetylase inhibitor-induced EBV lytic gene expression in nasopharyngeal carcinoma cells. Restoration of p53 in p53-null, EBV-infected H1299 cells augments the potential for viral lytic cycle initiation. Evidence from reporter assays demonstrated that p53 contributes to the expression of the immediate-early viral Zta gene. Further analysis indicated that the DNA-binding ability of p53 and phosphorylation of Ser392 may be critical. This study provides the first evidence that p53 is involved in the regulation of EBV lytic cycle initiation.


Subject(s)
Herpesvirus 4, Human/physiology , Histone Deacetylase Inhibitors , Trans-Activators/biosynthesis , Tumor Suppressor Protein p53/metabolism , Virus Activation , Cell Line, Tumor , Genetic Complementation Test , Humans , Tumor Suppressor Protein p53/deficiency
16.
J Biol Chem ; 281(13): 8806-14, 2006 Mar 31.
Article in English | MEDLINE | ID: mdl-16431925

ABSTRACT

Although spleen tyrosine kinase (Syk) is known to be important in hematopoietic cell development, the roles of Syk in epithelial cells have not been well studied. Limited data suggest that Syk plays alternate roles in carcinogenesis under different circumstances. In breast cancer, Syk has been suggested to be a tumor suppressor. In contrast, Syk is essential for murine mammary tumor virus-mediated transformation. However, the roles of Syk in tumor migration are still largely unknown. Nasopharyngeal carcinoma, an unusually highly metastatic tumor, expresses Epstein-Barr virus LMP2A (latent membrane protein 2A) in most clinical specimens. Previously, we demonstrated LMP2A triggers epithelial cell migration. LMP2A contains an immunoreceptor tyrosine-based activation motif, which is important for Syk kinase activation in B cells. In this study, we explored whether Syk is important for LMP2A-mediated epithelial cell migration. We demonstrate that LMP2A expression can activate endogenous Syk activity. The activation requires the tyrosine residues in LMP2A ITAM but not YEEA motif, which is important for Syk activation by Lyn in B cells. LMP2A interacts with Syk as demonstrated by coimmunoprecipitation and confocal microscopy. Furthermore, LMP2A-induced cell migration is inhibited by a Syk inhibitor and short interfering RNA. Tyrosines 74 and 85 in the LMP2A immunoreceptor tyrosine-based activation motif are essential for both Syk activation and LMP2A-mediated cell migration, indicating the involvement of Syk in LMP2A-triggered cell migration. The LMP2A-Syk pathway may provide suitable drug targets for treatment of nasopharyngeal carcinoma.


Subject(s)
Cell Movement , Epithelial Cells/physiology , Intracellular Signaling Peptides and Proteins/metabolism , Protein-Tyrosine Kinases/metabolism , Viral Matrix Proteins/metabolism , Amino Acid Sequence , Blotting, Western , Cell Line , Clone Cells , Enzyme Activation , Fluorescein-5-isothiocyanate , Fluorescent Antibody Technique, Indirect , Fluorescent Dyes , Histocytochemistry , Humans , Microscopy, Confocal , Molecular Sequence Data , Phosphorylation , Precipitin Tests , Protein Structure, Tertiary , Protein-Tyrosine Kinases/analysis , Sequence Deletion , Syk Kinase , Tyrosine/chemistry , Viral Matrix Proteins/chemistry , Viral Matrix Proteins/genetics
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