Activator protein-1 (AP-1) is an inducible transcription factor that contributes to the generation of chronic inflammation in response to oxidative and electrophilic stress. Previous studies have demonstrated that the PI3K/Akt1 pathway plays an important role in the transcriptional regulation of AP-1 expression. Although the histone post-translational modifications (PTMs) are assumed to affect the AP-1 transcriptional regulation by the PI3K/Akt pathway, the detailed mechanisms are completely unknown. In the present study, we show that heterochromatin 1 gamma (HP1gamma) plays a negative role in TPA-induced c-Jun and c-Fos expression. We show that TPA-induced Akt1 directly phosphorylates HP1gamma, abrogates its suppressive function and increases the interaction between histone H3 and 14-3-3epsilon. Collectively, these our data illustrate that the activation of PI3K/Akt pathway may play a permissive role in the recruitment of histone readers or other coactivators on the chromatin, thereby affecting the degree of AP-1 transcription.
Chromatin ; Heterochromatin ; Histones ; Inflammation ; Phosphorylation* ; Protein Processing, Post-Translational ; Transcription Factor AP-1* ; Transcription Factors

BACKGROUND: Cyclooxygenase-2 (COX-2) is an enzyme that promotes proliferation of tumor cells. HuR is a member of the family of embryonic lethal abnormal vision-like proteins. Recent studies show that cytoplasmic HuR stabilizes the mRNA of COX-2 and regulates the expression of COX-2. Moreover, cytoplasmic HuR expression is associated with a poorer prognosis for patients with some cancers. The aim of this study was to investigate the expression patterns of and the relationship between COX-2 and HuR in gallbladder carcinoma. METHODS: We analyzed COX-2 and HuR expression by immunohistochemical staining of 108 gallbladder carcinomas. RESULTS: COX-2 expression and nuclear and cytoplasmic HuR expression were seen in, respectively, 61 (56.5%), 77 (71.3%), and 4 (3.7%) cases. COX-2 and nuclear HuR were simultaneously expressed in 44 of the 108 samples without any quantitative association between the levels of each. COX-2 expression correlated with tumor stage, differentiation (based on histology), lymph node metastasis, perineural invasion, and survival. Nuclear and cytological expression of HuR did not correlate with any clinical parameters. CONCLUSIONS: COX-2 expression but not HuR may play an important role in the prognosis of patients with gallbladder carcinoma.
Cyclooxygenase 2 ; Cytoplasm ; Gallbladder ; Gallbladder Neoplasms ; ELAV Proteins ; ELAV-Like Protein 1 ; Humans ; Lymph Nodes ; Neoplasm Metastasis ; Prognosis ; Proteins ; RNA, Messenger

Genomic instability, which occurs through both genetic mechanisms (underlying inheritable phenotypic variations caused by DNA sequence-dependent alterations, such as mutation, deletion, insertion, inversion, translocation, and chromosomal aneuploidy) and epigenomic aberrations (underlying inheritable phenotypic variations caused by DNA sequence-independent alterations caused by a change of chromatin structure, such as DNA methylation and histone modifications), is known to promote tumorigenesis and tumor progression. Mechanisms involve both genomic instability and epigenomic aberrations that lose or gain the function of genes that impinge on tumor suppression/prevention or oncogenesis. Growing evidence points to an epigenome-wide disruption that involves large-scale DNA hypomethylation but specific hypermethylation of tumor suppressor genes, large blocks of aberrant histone modifications, and abnormal miRNA expression profile. Emerging molecular details regarding the modulation of these epigenetic events in cancer are used to illustrate the alterations of epigenetic molecules, and their consequent malfunctions could contribute to cancer biology. More recently, intriguing evidence supporting that genetic and epigenetic mechanisms are not separate events in cancer has been emerging; they intertwine and take advantage of each other during tumorigenesis. In addition, we discuss the collusion between epigenetics and genetics mediated by heterochromatin protein 1, a major component of heterochromatin, in order to maintain genome integrity.
Biology ; Carcinogenesis ; Chromatin ; DNA ; DNA Methylation ; Epigenomics* ; Genes, Tumor Suppressor ; Genetics* ; Genome ; Genomic Instability ; Heterochromatin ; Histones ; MicroRNAs ; Sequence Deletion

Genetic information stored in DNA is accurately copied and transferred to subsequent generations through DNA replication. This process is accomplished through the concerted actions of highly conserved DNA replication components. Epigenetic information stored in the form of histone modifications and DNA methylation, constitutes a second layer of regulatory information important for many cellular processes, such as gene expression regulation, chromatin organization, and genome stability. During DNA replication, epigenetic information must also be faithfully transmitted to subsequent generations. How this monumental task is achieved remains poorly understood. In this review, we will discuss recent advances on the role of DNA replication components in the inheritance of epigenetic marks, with a particular focus on epigenetic regulation in fission yeast. Based on these findings, we propose that specific DNA replication components function as key regulators in the replication of epigenetic information across the genome.
Cdc20 Proteins ; antagonists & inhibitors ; genetics ; metabolism ; Centromere ; metabolism ; Chromatin ; metabolism ; Chromosomal Proteins, Non-Histone ; metabolism ; DNA Replication ; DNA, Fungal ; metabolism ; Epigenesis, Genetic ; Histones ; metabolism ; Schizosaccharomyces ; genetics ; metabolism ; Schizosaccharomyces pombe Proteins ; antagonists & inhibitors ; genetics ; metabolism

Chromosomal Proteins, Non-Histone ; chemistry ; genetics ; metabolism ; HeLa Cells ; Histones ; chemistry ; genetics ; metabolism ; Humans ; Protein Domains

No abstract available.
Chromatin* ; DNA* ; Epigenomics* ; Histones* ; Methylation*

OBJECTIVETo prokaryoticly express and purify HuD protein and its RNA recognition motifs.

METHODSHuD protein was prokaryoticly expressed and purified by molecular cloning technology. Its biologic activity was testified by Western Blot.

RESULTSPurified HuD protein and its RNA recognized motifs were observed.

CONCLUSIONSThe result might aid for basic research and clinical application.

Antibodies, Antinuclear ; biosynthesis ; genetics ; isolation & purification ; Carcinoma, Small Cell ; genetics ; immunology ; metabolism ; Cloning, Molecular ; DNA, Complementary ; genetics ; ELAV Proteins ; ELAV-Like Protein 4 ; Humans ; Lung Neoplasms ; genetics ; immunology ; metabolism ; Nerve Tissue Proteins ; biosynthesis ; genetics ; isolation & purification ; Neurons ; immunology ; Paraneoplastic Syndromes, Nervous System ; genetics ; immunology ; metabolism ; RNA-Binding Proteins ; biosynthesis ; genetics ; isolation & purification

Chromatin texture, which partly reflects nuclear organization, is evolving as an important parameter indicating cell activation or transformation. In this study, chromatin pattern was evaluated by image analysis of the electron micrographs of follicular and papillary carcinoma cells of the thyroid gland and tested for discrimination of the two neoplasms. Digital grey images were converted from the electron micrographs; nuclear images, excluding nucleolus and intranuclear cytoplasmic inclusions, were obtained by segmentation; grey levels were standardized; and grey level histograms were generated. The histograms in follicular carcinoma showed Gaussian or near-Gaussian distribution and had a single peak, whereas those in papillary carcinoma had two peaks(bimodal), one at the black zone and the other at the white zone. In papillary carcinoma. the peak in the black zone represented an increased amount of heterochromatin particles and that at the white zone represented decreased electron density of euchromatin or nuclear matrix. These results indicate that the nuclei of follicular and papillary carcinoma cells differ intheir chromatin pattern and the difference may be due to decondensed chromatin and/or matrix substances.
Carcinoma, Papillary ; Chromatin* ; Discrimination (Psychology)* ; Euchromatin ; Heterochromatin ; Inclusion Bodies ; Normal Distribution ; Nuclear Matrix ; Thyroid Gland*

PURPOSE: Heterochromatin protein 1gamma (HP1gamma) interacts with chromosomes by binding to lysine 9-methylated histone H3 or DNA/RNA. HP1gamma is involved in various biological processes. The purpose of this study is to gain an understanding of how HP1gamma functions in these processes by identifying HP1gamma-binding proteins using mass spectrometry. MATERIALS AND METHODS: We performed affinity purification of HP1gamma-binding proteins using G1/S phase or prometaphase HEK293T cell lysates that transiently express mock or FLAG-HP1gamma. Coomassie staining was performed for HP1gamma-binding complexes, using cell lysates prepared by affinity chromatography FLAG-agarose beads, and the bands were digested and then analyzed using a mass spectrometry. RESULTS: We identified 99 HP1gamma-binding proteins with diverse cellular functions, including spliceosome, regulation of the actin cytoskeleton, tight junction, pathogenic Escherichia coli infection, mammalian target of rapamycin signaling pathway, nucleotide excision repair, DNA replication, homologous recombination, and mismatch repair. CONCLUSION: Our results suggested that HP1gamma is functionally active in DNA damage response via protein-protein interaction.
Actin Cytoskeleton ; Biological Processes ; Chromatography, Affinity ; DNA Damage* ; DNA Mismatch Repair ; DNA Repair ; DNA Replication ; DNA* ; Escherichia coli Infections ; Heterochromatin* ; Histones ; Homologous Recombination ; Lysine ; Mass Spectrometry ; Prometaphase ; Sirolimus ; Spliceosomes ; Tight Junctions

BACKGROUND: Tauopathies, a class of neurodegenerative diseases that includes Alzheimer's disease (AD), are characterized by the deposition of neurofibrillary tangles composed of hyperphosphorylated tau protein in the human brain. As abnormal alterations in histone acetylation and methylation show a cause and effect relationship with AD, we investigated the role of several Jumonji domain-containing histone demethylase (JHDM) genes, which have yet to be studied in AD pathology. METHODS: To examine alterations of several JHDM genes in AD pathology, we performed bioinformatics analyses of JHDM gene expression profiles in brain tissue samples from deceased AD patients. Furthermore, to investigate the possible relationship between alterations in JHDM gene expression profiles and AD pathology in vivo, we examined whether tissue-specific downregulation of JHDM Drosophila homologs (kdm) can affect tauR406W-induced neurotoxicity using transgenic flies containing the UAS-Gal4 binary system. RESULTS: The expression levels of JHDM1A, JHDM2A/2B, and JHDM3A/3B were significantly higher in postmortem brain tissue from patients with AD than from non-demented controls, whereas JHDM1B mRNA levels were downregulated in the brains of patients with AD. Using transgenic flies, we revealed that knockdown of kdm2 (homolog to human JHDM1), kdm3 (homolog to human JHDM2), kdm4a (homolog to human JHDM3A), or kdm4b (homolog to human JHDM3B) genes in the eye ameliorated the tauR406W-engendered defects, resulting in less severe phenotypes. However, kdm4a knockdown in the central nervous system uniquely ameliorated tauR406W-induced locomotion defects by restoring heterochromatin. CONCLUSION: Our results suggest that downregulation of kdm4a expression may be a potential therapeutic target in AD.
Acetylation ; Alzheimer Disease ; Brain ; Central Nervous System ; Computational Biology ; Diptera ; Down-Regulation ; Drosophila melanogaster ; Drosophila ; Heterochromatin ; Histones ; Humans ; Locomotion ; Methylation ; Neurodegenerative Diseases ; Neurofibrillary Tangles ; Pathology ; Phenotype ; RNA, Messenger ; tau Proteins ; Tauopathies ; Transcriptome