Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 19 de 19
Filter
1.
Int J Psychiatry Med ; : 912174241244479, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38562034

ABSTRACT

OBJECTIVE: Allostatic load (AL) is an indicator of cumulative wear and tear on the body's physiological systems that can predict the onset of a range of health problems. However, the relationship between AL and depression in patients with sleep disorders remains unclear. This study aimed to explore the association between AL and depression in patients with sleep disorders. METHODS: Using data from the 2015-2016 National Health and Nutrition Examination Survey, a total of 4618 adults aged 18 years and older in the United States were included in this cross-sectional analysis. AL was calculated using nine biological markers, with a score of ≥3 indicating a high level. Depression was assessed using the Patient Health Questionnaire-9, and a score of 10 or higher indicated a potential risk of depression. Logistic regression models were employed to analyze the relationship between AL and depression. RESULTS: Among the 1309 participants diagnosed with sleep disorders, 212 (16.2%) were identified as being at risk of depression. A total of 55.2% (n = 117) of the depressed persons had high AL levels. In the unadjusted model, AL levels were associated with depression in those with sleep disorders (OR:1.53, 95% CI = 1.14-2.05; P < .01). This relationship remained significant in the adjusted model (OR:1.52, 95% CI = 1.11-2.10, P < .05), after controlling for potential confounding factors. CONCLUSION: The findings showed that high AL levels in patients with sleep disorders were positively associated with depression, indicating that elevated AL may increase the risk of depression in this population, or alternatively, depression may increase the risk of AL.

2.
BMC Psychiatry ; 23(1): 951, 2023 12 18.
Article in English | MEDLINE | ID: mdl-38110900

ABSTRACT

BACKGROUND: Cue exposure therapy is used to treat alcohol dependence. However, its effectiveness is controversial due to the limitations of the clinical treatment setting. Virtual reality technology may improve the therapeutic effect. The aim of this study is to explore whether virtual reality-based cue exposure therapy can reduce the psychological craving and physiological responses of patients with alcohol dependence. METHODS: Forty-four male alcohol-dependent patients were recruited and divided into the study group (n = 23) and the control group (n = 21) according to a random number table. The control group received only conventional clinical treatment for alcohol dependence. The study group received conventional clinical treatment with the addition of VR cue exposure (treatment). The primary outcome was to assess psychological craving and physiological responses to cues of patients before and after treatment. RESULTS: After virtual reality-based cue exposure therapy, the changes in VAS and heart rate before and after cue exposure in the study group were significantly lower than those in the control group (P < 0.05), while the changes in skin conductance and respiration between the study group and the control group were not significantly different (P > 0.05). The changes in VAS and heart rate before and after cue exposure in the study group were significantly lower than those before treatment (P < 0.05), while the changes in skin conductance and respiration were not significantly different from those before treatment (P > 0.05). The changes in VAS, heart rate, skin conductance and respiration before and after cue exposure in the control group were not significantly different from those before treatment (P > 0.05). CONCLUSION: Virtual reality-based cue exposure therapy can reduce the psychological craving and part of the physiological responses of alcohol-dependent patients during cue exposure in the short term and may be helpful in the treatment of alcohol dependence. TRIAL REGISTRATION: The study protocol was registered at the China Clinical Trial Registry on 26/02/2021 ( www.chictr.org.cn ; ChiCTR ID: ChiCTR2100043680).


Subject(s)
Alcoholism , Implosive Therapy , Virtual Reality , Humans , Male , Craving/physiology , Alcoholism/therapy , Cues , Ethanol
3.
mBio ; : e0239223, 2023 Nov 14.
Article in English | MEDLINE | ID: mdl-37962470

ABSTRACT

IMPORTANCE: Intestinal microbiome dysbiosis is associated with psychiatric disease through the "microbiota-gut-brain" axis. Here, we revealed that there was obvious intestinal microbiome (including bacterial and fungal) dysbiosis in alcohol-dependent patients. Alcohol consumption seriously disturbs the gut equilibrium between bacteria and fungi, reduces the interactions among bacterial-fungal trans-kingdom, and increases intestinal permeability. Gut microbiota should be considered as a whole to study the development of alcohol dependence. The gut microbiome of alcohol-dependent patients increased the anxiety- and depression-like behavior in rats. The gut microbiota dysbiosis may promote the development of alcohol dependence by regulating the endogenous cholecystokinin (CCK) and related receptors. Hence, regulating the balance of gut microbiota and the endogenous CCK may be a potential strategy for reducing the risk of relapse in alcohol addiction patients.

4.
J Equine Vet Sci ; 119: 104160, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36343831

ABSTRACT

Infundibular caries (IC) affects donkeys of all ages and causes pain, difficulty in mastication and weight loss. The study aimed to determine the epidemiology of IC in donkeys and examine the potential risk factors associated with the disease development. A total of 2118 donkeys in Inner Mongolia were sampled. The first section of the survey was performed by veterinarians and included the oral health of the donkeys. A survey on the donkey's signalment, diet, and husbandry was also conducted. The risk factors associated with IC were assessed using multivariable logistic regression analysis. Univariate analysis of 11 variables assessed revealed that only four factors, including age, type of forage, pasture time and water source, increased the risk of IC. The findings of this study enhance our knowledge of the management and prevention of IC in donkeys.


Subject(s)
Dental Caries , Equidae , Animals , China , Dental Caries/etiology , Dental Caries/prevention & control , Dental Caries/veterinary , Diet , Risk Factors , Surveys and Questionnaires
5.
BMC Evol Biol ; 20(1): 140, 2020 10 31.
Article in English | MEDLINE | ID: mdl-33129255

ABSTRACT

BACKGROUND: EP300 is a conserved protein in vertebrates, which serves as a key mediator of cellular homeostasis. Mutations and dysregulation of EP300 give rise to severe human developmental disorders and malignancy. Danio rerio is a promising model organism to study EP300 related diseases and drugs; however, the effect of EP300 duplicates derived from teleost-specific whole genome duplication should not just be neglected. RESULTS: In this study, we obtained EP300 protein sequences of representative teleosts, mammals and sauropsids, with which we inferred a highly supported maximum likelihood tree. We observed that Ep300 duplicates (Ep300a and Ep300b) were widely retained in teleosts and universally expressed in a variety of tissues. Consensus sequences of Ep300a and Ep300b had exactly the same distribution of conserved domains, suggesting that their functions should still be largely overlapped. We analyzed the molecular evolution of Ep300 duplicates in teleosts, using branch-site models, clade models and site models. The results showed that both duplicates were subject to strong positive selection; however, for an extant species, generally at most one copy was under positive selection. At the clade level, there were evident positive correlations between evolutionary rates, the number of positively selected sites and gene expression levels. In Ostariophysi, Ep300a were under stronger positive selection than Ep300b; in Neoteleostei, another species-rich teleost clade, the contrary was the case. We also modeled 3D structures of zf-TAZ domain and its flanking regions of Ep300a and Ep300b of D. rerio and Oryzias latipes and found that in either species the faster evolving copy had more short helixes. CONCLUSIONS: Collectively, the two copies of Ep300 have undoubtedly experienced directional divergence in main teleost clades. The divergence of EP300 between teleosts and mammals should be greater than the divergence between different teleost clades. Further studies are needed to clarify to what extent the EP300 involved regulatory network has diverged between teleosts and mammals, which would also help explain the huge success of teleosts.


Subject(s)
E1A-Associated p300 Protein/genetics , Evolution, Molecular , Fishes/genetics , Genome , Animals , Gene Duplication , Oryzias/genetics , Phylogeny , Selection, Genetic , Zebrafish/genetics
6.
Blood ; 134(23): 2046-2058, 2019 12 05.
Article in English | MEDLINE | ID: mdl-31434700

ABSTRACT

Oncogenic EZH2 is overexpressed and extensively involved in the pathophysiology of different cancers including extranodal natural killer/T-cell lymphoma (NKTL). However, the mechanisms regarding EZH2 upregulation is poorly understood, and it still remains untargetable in NKTL. In this study, we examine EZH2 protein turnover in NKTL and identify MELK kinase as a regulator of EZH2 ubiquitination and turnover. Using quantitative mass spectrometry analysis, we observed a MELK-mediated increase of EZH2 S220 phosphorylation along with a concomitant loss of EZH2 K222 ubiquitination, suggesting a phosphorylation-dependent regulation of EZH2 ubiquitination. MELK inhibition through both chemical and genetic means led to ubiquitination and destabilization of EZH2 protein. Importantly, we determine that MELK is upregulated in NKTL, and its expression correlates with EZH2 protein expression as determined by tissue microarray derived from NKTL patients. FOXM1, which connected MELK to EZH2 signaling in glioma, was not involved in mediating EZH2 ubiquitination. Furthermore, we identify USP36 as the deubiquitinating enzyme that deubiquitinates EZH2 at K222. These findings uncover an important role of MELK and USP36 in mediating EZH2 stability in NKTL. Moreover, MELK overexpression led to decreased sensitivity to bortezomib treatment in NKTL based on deprivation of EZH2 ubiquitination. Therefore, modulation of EZH2 ubiquitination status by targeting MELK may be a new therapeutic strategy for NKTL patients with poor bortezomib response.


Subject(s)
Enhancer of Zeste Homolog 2 Protein/metabolism , Gene Expression Regulation, Neoplastic , Lymphoma, Extranodal NK-T-Cell/metabolism , Neoplasm Proteins/metabolism , Protein Serine-Threonine Kinases/metabolism , Bortezomib/therapeutic use , Cell Line, Tumor , Enhancer of Zeste Homolog 2 Protein/genetics , Forkhead Box Protein M1/genetics , Forkhead Box Protein M1/metabolism , Humans , Lymphoma, Extranodal NK-T-Cell/drug therapy , Lymphoma, Extranodal NK-T-Cell/genetics , Lymphoma, Extranodal NK-T-Cell/pathology , Neoplasm Proteins/genetics , Phosphorylation/genetics , Protein Serine-Threonine Kinases/genetics , Protein Stability , Ubiquitin Thiolesterase/genetics , Ubiquitin Thiolesterase/metabolism , Ubiquitination/genetics
7.
RNA Biol ; 16(2): 176-184, 2019 02.
Article in English | MEDLINE | ID: mdl-30608221

ABSTRACT

Polycomb repressive complex 2 (PRC2) and its methylation of histone 3 at lysine 27 (H3K27me3) play a crucial role in epigenetic regulation of normal development and malignancy. Several factors regulate the recruitment of PRC2 and affects its chromatin modification function. Over the past years, emerging discoveries have portrayed the association of RNA (protein-coding and non-coding) with PRC2 as a critical factor in understanding PRC2 function. With PRC2 being a macromolecular complex of interest in development and diseases, further studies are needed to relate the rapidly evolving PRC2:RNA biology in that scenario. In this review, we summarize the current understanding of different modes of RNA binding by PRC2, and further discuss perspectives, key questions and therapeutic applications of PRC2 binding to RNAs.


Subject(s)
Gene Expression Regulation , Polycomb-Group Proteins/metabolism , RNA/genetics , Animals , Humans , Models, Biological , Polycomb-Group Proteins/genetics , Protein Binding , RNA/metabolism , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , RNA, Small Untranslated/genetics , RNA, Small Untranslated/metabolism
8.
Eur J Pharm Sci ; 127: 14-23, 2019 Jan 15.
Article in English | MEDLINE | ID: mdl-30336203

ABSTRACT

An optimised 1,8-cineole-loaded self-microemulsifying drug delivery system (CIN-SMEDDS) with a mean droplet size, polydispersity index, mean zeta potential and encapsulation efficiency of 38.14 ±â€¯1.47 nm, 0.208 ±â€¯0.036, -9.312 ±â€¯1.764 mV and 95.35% ±â€¯1.13%, respectively, successfully ameliorated the lipopolysaccharide (LPS)-induced endothelial injury in mice. Acute toxicity assay in mice through the oral administration of CIN-SMEDDS showed that the median lethal dose of CIN-SMEDDS was 2998.9 mg/kg. The results of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay indicated that the cytotoxicity of CIN-SMEDDS to Caco-2 cells may be ascribed to the surfactant/co-surfactant mixture. In particular, CIN-SMEDDS remarkably inhibited inflammatory cytokines IL-1ß, IL-6 and IL-8 with a simultaneous increase in IL-10 in LPS-treated mice. Haematoxylin-eosin staining results showed that CIN-SMEDDS attenuated LPS-induced vascular endothelial injury. Western blot results showed that the vascular protective effects of CIN-SMEDDS were associated with the NF-κB and peroxisome proliferator-activated receptor γ signalling pathways. These findings indicated that CIN-SMEDDS can attenuate LPS-induced endothelial injury and thus was proposed as a promising agent for the treatment of inflammatory cardiovascular disease.


Subject(s)
Aorta, Thoracic/drug effects , Eucalyptol/administration & dosage , Protective Agents/administration & dosage , Animals , Aorta, Thoracic/injuries , Caco-2 Cells , Cytokines/blood , Emulsions , Endothelium, Vascular/drug effects , Eucalyptol/toxicity , Female , Humans , Lethal Dose 50 , Lipopolysaccharides , Male , Mice , Protective Agents/toxicity
9.
Oncotarget ; 9(61): 31832-31841, 2018 Aug 07.
Article in English | MEDLINE | ID: mdl-30159126

ABSTRACT

Natural killer/T-cell lymphoma (NKTCL) is an aggressive non-Hodgkin lymphoma that has been facing limited success with conventional treatments, urging for the discovery of alternative strategies. Recent studies including ours have revealed that EZH2 and JAK-STAT signalling pathways are key contributors to NKTCL pathogenesis. In particular, we found that EZH2 is overexpressed and directly transcriptionally activates the CCND1 gene to confer growth advantage. CCND1 codes for cyclin D1, which complexes with CDK4/6 to promote G1 to S phase transition. Therefore in this study we investigated whether inhibiting both JAK1/2 and CDK4/6, using LEE011 and ruxolitinib respectively is effective in NKTL. We first demonstrate that separate LEE011 and ruxolitinib treatment is sufficient to cause growth inhibition of NKTCL cells. More importantly, we found that there is synergistic growth inhibitory effects on NKTCL cells with combination treatment of LEE011 and ruxolitinib. The results obtained shows that the targeting of both CDK4/6 and JAK1/2 are promising to develop better treatment alternatives for NKTCL.

10.
Biochem Biophys Res Commun ; 488(1): 196-203, 2017 06 17.
Article in English | MEDLINE | ID: mdl-28487109

ABSTRACT

C-C chemokine receptor type 4 has been reported to correlate with lung cancer. However, the role of CCR4 in human non-small cell lung cancer patients is not well defined. Here, we demonstrated that increased expression of CCR4 was associated with clinical stage and CCR4 was an independent risk factor for overall survival in NSCLC patients. Moreover, tumor-infiltrating Treg cells were higher expression than matched adjacent tissues in CCR4+ NSCLC. Higher expression of chemokine CCL17 and CCL22 could recruit Treg cells to tumor sites in NSCLC. Treg in TIL exhibit a higher level of suppressive activity on effector T cells than matched adjacent tissues in NSCLC patients. Significant NK cell reduction was observed in tumor regions compared to non-tumor regions. NK cells demonstrated that reduced the killing capacity against target cells and the expression of CD69 + in vitro. The addition of Treg cells from NSCLC patients efficiently inhibited the anti-tumor ability of autologous NK cells. Treatment with anti-TGF-ß antibody restored the impaired cytotoxic activity of T cells and NK cells from tumor tissues. Our results indicate that TGF-ß plays an important role in impaired Teff cells and NK cells. It will therefore be valuable to develop therapeutic strategies against CCR4 and TGF-ß pathway for therapy of NSCLC.


Subject(s)
Carcinoma, Non-Small-Cell Lung/metabolism , Chemotaxis , Killer Cells, Natural/metabolism , Lung Neoplasms/metabolism , Receptors, CCR4/metabolism , T-Lymphocytes/metabolism , Transforming Growth Factor beta/metabolism , Female , Humans , Male , Middle Aged
11.
Blood ; 128(7): 948-58, 2016 08 18.
Article in English | MEDLINE | ID: mdl-27297789

ABSTRACT

The best-understood mechanism by which EZH2 exerts its oncogenic function is through polycomb repressive complex 2 (PRC2)-mediated gene repression, which requires its histone methyltransferase activity. However, small-molecule inhibitors of EZH2 that selectively target its enzymatic activity turn out to be potent only for lymphoma cells with EZH2-activating mutation. Intriguingly, recent discoveries, including ours, have placed EZH2 into the category of transcriptional coactivators and thus raised the possibility of noncanonical signaling pathways. However, it remains unclear how EZH2 switches to this catalytic independent function. In the current study, using natural killer/T-cell lymphoma (NKTL) as a disease model, we found that phosphorylation of EZH2 by JAK3 promotes the dissociation of the PRC2 complex leading to decreased global H3K27me3 levels, while it switches EZH2 to a transcriptional activator, conferring higher proliferative capacity of the affected cells. Gene expression data analysis also suggests that the noncanonical function of EZH2 as a transcriptional activator upregulates a set of genes involved in DNA replication, cell cycle, biosynthesis, stemness, and invasiveness. Consistently, JAK3 inhibitor was able to significantly reduce the growth of NKTL cells, in an EZH2 phosphorylation-dependent manner, whereas various compounds recently developed to inhibit EZH2 methyltransferase activity have no such effect. Thus, pharmacological inhibition of JAK3 activity may provide a promising treatment option for NKTL through the novel mechanism of suppressing noncanonical EZH2 activity.


Subject(s)
Enhancer of Zeste Homolog 2 Protein/metabolism , Janus Kinase 3/metabolism , Lymphoma, T-Cell/metabolism , Natural Killer T-Cells/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Proliferation/genetics , Enzyme Activation/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Histones/metabolism , Humans , Lymphoma, T-Cell/genetics , Lymphoma, T-Cell/pathology , Lysine/metabolism , Methylation/drug effects , Models, Biological , Natural Killer T-Cells/drug effects , Neoplasm Proteins , Phosphorylation/drug effects , Phosphotyrosine/metabolism , Polycomb Repressive Complex 2/metabolism , Protein Binding/drug effects , Protein Kinase Inhibitors/pharmacology , Protein Subunits/metabolism , RNA Polymerase II/metabolism , Transcription Factors
12.
Ying Yong Sheng Tai Xue Bao ; 26(5): 1553-62, 2015 May.
Article in Chinese | MEDLINE | ID: mdl-26571677

ABSTRACT

Culturable endophytic bacteria were isolated from medicinal plant Ilex cornuta by plate-spreading method, strains with strong inhibitory effect on phytopathogen were screened by confrontation culture and fermentation filtrate culture methods, and the morphological changes of phytopathogen hyphae treated with endophytic bacteria were examined by microscopy and micrograph. Their phylogenetic relationships were determined by homology analysis of the 16S rDNA sequences of PCR products and the taxonomic status of the selected strains was determined based on their morphology, physiology, biochemical test results and 16S rDNA sequence analysis. A total of 85 endophytic bacteria were isolated from the healthy roots, stems, leaves and fruits of I. cornuta, and 10 strains of them showed strong inhibitory effect on Alternaria alternata, Magnaporthe grisea, Fusarium oxysporum, and were preliminarily identified belonging to four genera and seven species. Three strains with the strongest inhibitory effect, GG78 (60.3%), GG31 (48.1%) and GG13 (61.0%) belonged to Enterobacter cloacae, Enterobacter ludwigii and Bacillus cereus, respectively. Microscopic analyses showed that the inhibited phytopathogen hyphae became deformed, distorted, and partially expanded forming plasma concentration and hair-like branch on the hyphae base. These morphological changes could be caused by the extracellular metabolic substances secreted by the endophytic bacteria, such as antibiotics, hydrolytic enzymes, alkaloids and so on.


Subject(s)
Bacteria/classification , Ilex/microbiology , Plants, Medicinal/microbiology , Probiotics , Endophytes/classification , Fruit , Phylogeny , Plant Leaves , Plant Roots , RNA, Ribosomal, 16S/genetics
13.
Oncotarget ; 6(28): 26508-18, 2015 Sep 22.
Article in English | MEDLINE | ID: mdl-26164366

ABSTRACT

Epigenetic alterations have emerged as an important cause of microRNA (miRNA) deregulation. In Multiple Myeloma (MM), a few tumor suppressive miRNAs silenced by DNA hypermethylation have been reported, but so far there are few systemic investigations on epigenetically silenced miRNAs. We conducted genome-wide screening for tumor suppressive miRNAs epigenetically silenced in MM. Four Human MM Cell lines were treated with demethylating agent 5'azacytidine (5'aza). Consistently upregulated miRNAs include miR-155, miR-198, miR-135a*, miR-200c, miR-125a-3p, miR-188-5p, miR-483-5p, miR-663, and miR-630. Methylation array analysis revealed increased methylation at or near miRNA-associated CpG islands in MM patients. Ectopic restoration of miR-155, miR-198, miR-135a*, miR-200c, miR-663 and miR-483-5p significantly repressed MM cell proliferation, migration and colony formation. Furthermore, we derived a 33-gene signature from predicted miRNA target genes that were also upregulated in MM patients and associated with patient survival in three independent myeloma datasets. In summary, we have revealed important, epigenetically silenced tumor suppressive miRNAs by pharmacologic reversal of epigenetic silencing.


Subject(s)
Biomarkers, Tumor/genetics , DNA Methylation/drug effects , Gene Silencing/drug effects , MicroRNAs/genetics , Multiple Myeloma/genetics , Biomarkers, Tumor/metabolism , Cell Line, Tumor , Cell Movement , Cell Proliferation , Computational Biology , DNA Modification Methylases/antagonists & inhibitors , DNA Modification Methylases/metabolism , Enzyme Inhibitors/pharmacology , Gene Expression Profiling/methods , Gene Expression Regulation, Neoplastic , Genetic Predisposition to Disease , Genome-Wide Association Study , Humans , MicroRNAs/metabolism , Multiple Myeloma/metabolism , Multiple Myeloma/mortality , Multiple Myeloma/pathology , Oligonucleotide Array Sequence Analysis , Phenotype , Proportional Hazards Models
14.
Br J Haematol ; 163(1): 93-103, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23888996

ABSTRACT

Acute lymphoblastic leukaemia (ALL) is the most common paediatric malignancy. Although 90% of patients are now long-term survivors, the remaining 10% have poor outcome predominantly due to drug resistance. In this study, we carried out genome-wide microRNA (miRNA) microarray analysis on diagnostic bone marrow samples to determine miRNA expression profiles associated with poor outcome in ALL. A reduced expression of MIR335 was identified as the most significant miRNA abnormality associated with poor outcome. It is well known that glucocorticoid (GC) resistance is one of the major reasons contributing to poor outcome. We show that exogenous expression of MIR335 in ALL cells increases sensitization to prednisolone-mediated apoptosis. Moreover, we demonstrate that MAPK1 is a novel target of MIR335, and that MEK/ERK inhibitor treatment enhanced prednisolone-induced cell death through the activation of BIM (BCL2L11). These results provide a possible underlying molecular mechanism to explain the association between reduced MIR335 with poor clinical outcome, and suggest that approaches to re-introduce MIR335 expression or override MAPK1 activity may offer promising therapeutic strategies in the treatment of ALL.


Subject(s)
MicroRNAs/genetics , Mitogen-Activated Protein Kinase 1/genetics , Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics , Precursor Cell Lymphoblastic Leukemia-Lymphoma/mortality , Cell Line, Tumor , Child , Child, Preschool , Computational Biology/methods , Drug Resistance, Neoplasm/genetics , Female , Gene Expression , Gene Expression Profiling , Gene Expression Regulation, Leukemic , Genetic Vectors/genetics , Humans , Lentivirus/genetics , MAP Kinase Signaling System/drug effects , Male , Mitogen-Activated Protein Kinase 1/antagonists & inhibitors , Mitogen-Activated Protein Kinase 1/metabolism , Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy , Prednisolone/pharmacology , Prednisolone/therapeutic use , Prognosis , Recurrence
15.
Mol Cell ; 50(6): 844-55, 2013 Jun 27.
Article in English | MEDLINE | ID: mdl-23727019

ABSTRACT

The extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase signal-transduction cascade is one of the key pathways regulating proliferation and differentiation in development and disease. ERK signaling is required for human embryonic stem cells' (hESCs') self-renewing property. Here, we studied the convergence of the ERK signaling cascade at the DNA by mapping genome-wide kinase-chromatin interactions for ERK2 in hESCs. We observed that ERK2 binding occurs near noncoding genes and histone, cell-cycle, metabolism, and pluripotency-associated genes. We find that the transcription factor ELK1 is essential in hESCs and that ERK2 co-occupies promoters bound by ELK1. Strikingly, promoters bound by ELK1 without ERK2 are occupied by Polycomb group proteins that repress genes involved in lineage commitment. In summary, we propose a model wherein extracellular-signaling-stimulated proliferation and intrinsic repression of differentiation are integrated to maintain the identity of hESCs.


Subject(s)
Chromatin/enzymology , Embryonic Stem Cells/enzymology , MAP Kinase Signaling System , Mitogen-Activated Protein Kinase 1/metabolism , ets-Domain Protein Elk-1/metabolism , Base Sequence , Cell Differentiation , Cell Lineage , Cells, Cultured , Consensus Sequence , Embryonic Stem Cells/physiology , Gene Expression Regulation , Gene Knockdown Techniques , Genome, Human , Humans , Mitogen-Activated Protein Kinase 1/genetics , Polycomb-Group Proteins/genetics , Polycomb-Group Proteins/metabolism , Promoter Regions, Genetic , Protein Binding , RNA, Small Interfering/genetics , RNA, Small Nuclear/genetics , RNA, Small Nuclear/metabolism , Transcription, Genetic , Transcriptome , ets-Domain Protein Elk-1/genetics
16.
Blood ; 121(22): 4512-20, 2013 May 30.
Article in English | MEDLINE | ID: mdl-23529930

ABSTRACT

The role of enhancer of zeste homolog 2 (EZH2) in cancer is complex and may vary depending on the cellular context. We found that EZH2 is aberrantly overexpressed in the majority of natural killer/T-cell lymphoma (NKTL), an aggressive lymphoid malignancy with very poor prognosis. We show that EZH2 upregulation is mediated by MYC-induced repression of its regulatory micro RNAs and EZH2 exerts oncogenic properties in NKTL. Ectopic expression of EZH2 in both primary NK cells and NKTL cell lines leads to a significant growth advantage. Conversely, knock-down of EZH2 in NKTL cell lines results in cell growth inhibition. Intriguingly, ectopic EZH2 mutant deficient for histone methyltransferase activity is also able to confer growth advantage and rescue growth inhibition on endogenous EZH2 depletion in NKTL cells, indicating an oncogenic role of EZH2 independent of its gene-silencing activity. Mechanistically, we show that EZH2 directly promotes the transcription of cyclin D1 and this effect is independent of its enzymatic activity. Furthermore, depletion of EZH2 using a PRC2 inhibitor 3-deazaneplanocin A significantly inhibits growth of NK tumor cells. Therefore, our study uncovers an oncogenic role of EZH2 independent of its methyltransferase activity in NKTL and suggests that targeting EZH2 may have therapeutic usefulness in this lymphoma.


Subject(s)
Histone-Lysine N-Methyltransferase/metabolism , Killer Cells, Natural/physiology , Lymphoma, T-Cell/physiopathology , Polycomb Repressive Complex 2/genetics , Adenosine/analogs & derivatives , Adenosine/pharmacology , Adolescent , Adult , Aged , Aged, 80 and over , Apoptosis/drug effects , Apoptosis/physiology , Cell Line, Tumor , Cell Proliferation/drug effects , Cyclin D1/genetics , Cyclin D1/metabolism , Enhancer of Zeste Homolog 2 Protein , Female , Gene Expression Regulation, Neoplastic , Histone Methyltransferases , Histone-Lysine N-Methyltransferase/genetics , Humans , Killer Cells, Natural/cytology , Lymphoma, T-Cell/pathology , Male , MicroRNAs/metabolism , Middle Aged , Mutagenesis/physiology , Polycomb Repressive Complex 2/metabolism , Promoter Regions, Genetic/physiology , Up-Regulation/physiology , Young Adult
17.
J Integr Bioinform ; 9(2): 211, 2012 Sep 18.
Article in English | MEDLINE | ID: mdl-22987856

ABSTRACT

Advances in high throughput sequencing technology have enabled the identification of transcription factor (TF) binding sites in genome scale. TF binding studies are important for medical applications and stem cell research. Somatic cells can be reprogrammed to a pluripotent state by the combined introduction of factors such as Oct4, Sox2, c-Myc, Klf4. These reprogrammed cells share many characteristics with embryonic stem cells (ESCs) and are known as induced pluripotent stem cells (iPSCs). The signaling requirements for maintenance of human and murine embryonic stem cells (ESCs) differ considerably. Genome wide ChIP-seq TF binding maps in mouse stem cells include Oct4, Sox2, Nanog, Tbx3, Smad2 as well as group of other factors. ChIP-seq allows study of new candidate transcription factors for reprogramming. It was shown that Nr5a2 could replace Oct4 for reprogramming. Epigenetic modifications play important role in regulation of gene expression adding additional complexity to transcription network functioning. We have studied associations between different histone modification using published data together with RNA Pol II sites. We found strong associations between activation marks and TF binding sites and present it qualitatively. To meet issues of statistical analysis of genome ChIP-sequencing maps we developed computer program to filter out noise signals and find significant association between binding site affinity and number of sequence reads. The data provide new insights into the function of chromatin organization and regulation in stem cells.


Subject(s)
Chromatin/metabolism , Transcription Factors/chemistry , Transcription Factors/metabolism , Animals , Binding Sites , Chromatin Immunoprecipitation , Data Interpretation, Statistical , Embryonic Stem Cells/cytology , Embryonic Stem Cells/metabolism , Genome , Humans , Kruppel-Like Factor 4 , Mice , Pluripotent Stem Cells/metabolism
18.
Blood ; 118(18): 4919-29, 2011 Nov 03.
Article in English | MEDLINE | ID: mdl-21921041

ABSTRACT

We performed a comprehensive genome-wide miRNA expression profiling of extranodal nasal-type natural killer/T-cell lymphoma (NKTL) using formalin-fixed paraffin-embedded tissue (n = 30) and NK cell lines (n = 6) compared with normal NK cells, with the objective of understanding the pathogenetic role of miRNA deregulation in NKTL. Compared with normal NK cells, differentially expressed miRNAs in NKTL are predominantly down-regulated. Re-expression of down-regulated miRNAs, such as miR-101, miR-26a, miR26b, miR-28-5, and miR-363, reduced the growth of the NK cell line and modulated the expression of their predicted target genes, suggesting the potential functional role of the deregulated miRNAs in the oncogenesis of NKTL. Taken together, the predicted targets whose expression is inversely correlated with the expression of deregulated miRNA in NKTL are significantly enriched for genes involved in cell cycle-related, p53, and MAPK signaling pathways. We also performed immunohistochemical validation for selected target proteins and found overexpression of MUM1, BLIMP1, and STMN1 in NKTL, and notably, a corresponding increase in MYC expression. Because MYC is known to cause repression of miRNA expression, it is possible that MYC activation in NKTL may contribute to the suppression of the miRNAs regulating MUM1, BLIMP1, and STMN1.


Subject(s)
Lymphoma, Extranodal NK-T-Cell/genetics , MicroRNAs/genetics , Animals , Caenorhabditis elegans/genetics , Cell Line, Tumor , Cluster Analysis , Gene Expression Profiling , Gene Expression Regulation, Neoplastic/physiology , Humans , Killer Cells, Natural/metabolism , Killer Cells, Natural/pathology , Lymphoma, Extranodal NK-T-Cell/diagnosis , Lymphoma, Extranodal NK-T-Cell/metabolism , Lymphoma, Extranodal NK-T-Cell/therapy , MicroRNAs/metabolism , Microarray Analysis , Molecular Targeted Therapy , Prognosis , Signal Transduction/genetics , Signal Transduction/physiology , Transfection
19.
Proc Natl Acad Sci U S A ; 104(6): 1841-6, 2007 Feb 06.
Article in English | MEDLINE | ID: mdl-17264218

ABSTRACT

Tight regulation of p53 is essential for maintaining normal cell growth. Here we report that BLIMP1 acts in an autoregulatory feedback loop that controls p53 activity through repression of p53 transcription. p53 binds to and positively regulates BLIMP1, which encodes for a known B cell transcriptional repressor. Knockdown of BLIMP1 by siRNA results in both apoptosis and growth arrest in human colon cancer cells and cell-cycle arrest in primary human fibroblasts. Interestingly, the levels of both p53 mRNA and protein are substantially increased after BLIMP1 depletion, which is accompanied by the induction of p53 target genes. Importantly, the apoptosis induced by BLIMP1 depletion in HCT116 cells is largely abrogated in cells lacking p53 or in cells depleted in p53 by siRNA. We further demonstrate that BLIMP1 binds to the p53 promoter and represses p53 transcription, and this provides a mechanistic explanation for the induction of p53 response in cells depleted of BLIMP1. Hence, suppression of p53 transcription is a crucial function of endogenous BLIMP1 and is essential for normal cell growth.


Subject(s)
Cell Enlargement , Gene Expression Regulation/physiology , Repressor Proteins/physiology , Transcription Factors/physiology , Transcription, Genetic , Tumor Suppressor Protein p53/antagonists & inhibitors , Tumor Suppressor Protein p53/genetics , Cell Line , Cell Survival/genetics , HCT116 Cells , Humans , Positive Regulatory Domain I-Binding Factor 1 , Protein Binding/genetics , Repressor Proteins/metabolism , Transcription Factors/metabolism , Tumor Suppressor Protein p53/biosynthesis , Tumor Suppressor Protein p53/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL
...