ABSTRACT
Melanoma cell phenotype switching between differentiated melanocytic and undifferentiated mesenchymal-like states drives metastasis and drug resistance. CDK7 is the serine/threonine kinase of the basal transcription factor TFIIH. We show that dedifferentiation of melanocytic-type melanoma cells into mesenchymal-like cells and acquisition of tolerance to targeted therapies is achieved through chronic inhibition of CDK7. In addition to emergence of a mesenchymal-type signature, we identify a GATA6-dependent gene expression program comprising genes such as AMIGO2 or ABCG2 involved in melanoma survival or targeted drug tolerance, respectively. Mechanistically, we show that CDK7 drives expression of the melanocyte lineage transcription factor MITF that in turn binds to an intronic region of GATA6 to repress its expression in melanocytic-type cells. We show that GATA6 expression is activated in MITF-low melanoma cells of patient-derived xenografts. Taken together, our data show how the poorly characterized repressive function of MITF in melanoma participates in a molecular cascade regulating activation of a transcriptional program involved in survival and drug resistance in melanoma.
Subject(s)
Melanoma , Microphthalmia-Associated Transcription Factor , Cell Line, Tumor , Drug Tolerance , Gene Expression Regulation, Neoplastic , Humans , Melanoma/drug therapy , Melanoma/genetics , Microphthalmia-Associated Transcription Factor/genetics , Microphthalmia-Associated Transcription Factor/metabolismABSTRACT
Body-oriented psychotherapy has been an innovative practice in the treatment of anorexia for around ten years. This body-oriented and relational care is carried out on medical prescription individually or in groups, once or twice a week for six to eighteen months. The session comprises different moments of welcome, movement and exchange. This approach constitutes an interesting therapy which needs to be validated by research.
Subject(s)
Anorexia/therapy , Body Image , Psychotherapy/methods , Child , HumansABSTRACT
BACKGROUND: Microbial-associated molecular patterns activate several MAP kinases, which are major regulators of the innate immune response in Arabidopsis thaliana that induce large-scale changes in gene expression. Here, we determine whether microbial-associated molecular pattern-triggered gene expression involves modifications at the chromatin level. RESULTS: Histone acetylation and deacetylation are major regulators of microbial-associated molecular pattern-triggered gene expression and implicate the histone deacetylase HD2B in the reprogramming of defence gene expression and innate immunity. The MAP kinase MPK3 directly interacts with and phosphorylates HD2B, thereby regulating the intra-nuclear compartmentalization and function of the histone deacetylase. CONCLUSIONS: By studying a number of gene loci that undergo microbial-associated molecular pattern-dependent activation or repression, our data reveal a mechanistic model for how protein kinase signaling directly impacts chromatin reprogramming in plant defense.
Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/immunology , Chromatin Assembly and Disassembly , Chromatin/physiology , Histone Deacetylases/metabolism , Mitogen-Activated Protein Kinase Kinases/metabolism , Plant Immunity , Flagellin/immunology , Histones/metabolism , Immunity, Innate , Phosphorylation , Stress, PhysiologicalABSTRACT
BACKGROUND: Plant adaptive responses to changing environments involve complex molecular interplays between intrinsic and external signals. Whilst much is known on the signaling components mediating diurnal, light, and temperature controls on plant development, their influence on chromatin-based transcriptional controls remains poorly explored. RESULTS: In this study we show that a SWI/SNF chromatin remodeler subunit, BAF60, represses seedling growth by modulating DNA accessibility of hypocotyl cell size regulatory genes. BAF60 binds nucleosome-free regions of multiple G box-containing genes, opposing in cis the promoting effect of the photomorphogenic and thermomorphogenic regulator Phytochrome Interacting Factor 4 (PIF4) on hypocotyl elongation. Furthermore, BAF60 expression level is regulated in response to light and daily rhythms. CONCLUSIONS: These results unveil a short path between a chromatin remodeler and a signaling component to fine-tune plant morphogenesis in response to environmental conditions.
Subject(s)
Arabidopsis Proteins/genetics , Basic Helix-Loop-Helix Transcription Factors/genetics , Chromosomal Proteins, Non-Histone/genetics , DNA-Binding Proteins/genetics , Hypocotyl/growth & development , Seedlings/genetics , Transcription Factors/genetics , Arabidopsis/genetics , Arabidopsis/growth & development , Chromatin Assembly and Disassembly , DNA, Plant/genetics , Gene Expression Regulation, Plant , Hypocotyl/genetics , Nucleosomes/genetics , Seedlings/growth & developmentABSTRACT
Body mediation is today used as a tool for establishing a relationship with a young person experiencing psychological suffering. It is particularly useful in adolescence, a period marked by the destabilisation of emotional and relational fields.
Subject(s)
Adolescent Behavior/psychology , Body Image , Massage , Adolescent , Humans , Psychology, AdolescentABSTRACT
BACKGROUND: CREB and CREM are closely related factors that regulate transcription in response to various stress, metabolic and developmental signals. The CREMτ activator isoform is selectively expressed in haploid spermatids and plays an essential role in murine spermiogenesis. RESULTS: We have used chromatin immunoprecipitation coupled to sequencing (ChIP-seq) to map CREM and CREB target loci in round spermatids from adult mouse testis and spermatogonia derived GC1-spg cells respectively. We identify more than 9000 genomic loci most of which are cell-specifically occupied. Despite the fact that round spermatids correspond to a highly specialised differentiated state, our results show that they have a remarkably accessible chromatin environment as CREM occupies more than 6700 target loci corresponding not only to the promoters of genes selectively expressed in spermiogenesis, but also of genes involved in functions specific to other cell types. The expression of only a small subset of these target genes are affected in the round spermatids of CREM knockout animals. We also identify a set of intergenic binding loci some of which are associated with H3K4 trimethylation and elongating RNA polymerase II suggesting the existence of novel CREB and CREM regulated transcripts. CONCLUSIONS: We demonstrate that CREM and CREB occupy a large number of promoters in highly cell specific manner. This is the first study of CREM target promoters directly in a physiologically relevant tissue in vivo and represents the most comprehensive experimental analysis of CREB/CREM regulatory potential to date.
Subject(s)
Cyclic AMP Response Element Modulator/metabolism , Cyclic AMP Response Element-Binding Protein/metabolism , Genetic Loci/genetics , Spermatozoa/metabolism , Animals , Binding Sites , Cell Line , Chromatin Immunoprecipitation , Chromosomes, Mammalian/genetics , Gene Expression Regulation , Haploidy , Histones/metabolism , Lysine/metabolism , Male , Methylation , Mice , MicroRNAs/genetics , MicroRNAs/metabolism , Organ Specificity/genetics , Promoter Regions, Genetic/genetics , RNA, Messenger/genetics , RNA, Messenger/metabolism , Spermatids/cytology , Spermatids/metabolism , Spermatozoa/cytology , Testis/cytology , Testis/metabolismABSTRACT
POU3F2 is a POU-Homeodomain transcription factor expressed in neurons and melanoma cells. In melanoma lesions, cells expressing high levels of POU3F2 show enhanced invasive and metastatic capacity that can in part be explained by repression of Micropthalmia-associated Transcription Factor (MITF) expression via POU3F2 binding to its promoter. To identify other POU3F2 target genes that may be involved in modulating the properties of melanoma cells, we performed ChIP-chip experiments in 501Mel melanoma cells. 2108 binding loci located in the regulatory regions of 1700 potential target genes were identified. Bioinformatic and experimental assays showed the presence of known POU3F2-binding motifs, but also many AT-rich sequences with only partial similarity to the known motifs at the occupied loci. Functional analysis indicates that POU3F2 regulates the stem cell factor (Kit ligand, Kitl) promoter via a cluster of four closely spaced binding sites located in the proximal promoter. Our results suggest that POU3F2 may regulate the properties of melanoma cells via autocrine KIT ligand signalling.
Subject(s)
Gene Expression Regulation, Neoplastic , Genome, Human/genetics , Genome-Wide Association Study , Homeodomain Proteins/genetics , Melanoma/genetics , POU Domain Factors/genetics , Promoter Regions, Genetic , Stem Cell Factor/genetics , Amino Acid Motifs , Base Sequence , Binding Sites , CD36 Antigens/genetics , Cell Line, Tumor , Gene Knockdown Techniques , Genes, Neoplasm/genetics , Genetic Loci/genetics , Homeodomain Proteins/chemistry , Humans , Melanoma/pathology , Microphthalmia-Associated Transcription Factor/genetics , Molecular Sequence Data , POU Domain Factors/chemistry , Protein Binding , Skin Neoplasms/genetics , Skin Neoplasms/pathology , Transcriptional Activation/genetics , Wnt Proteins/geneticsABSTRACT
All-trans retinoic acid (RA) induces transforming growth factor beta (TGF-beta)-dependent autocrine growth of mouse embryonic fibroblasts (MEFs). We have used chromatin immunoprecipitation to map 354 RA receptor (RAR) binding loci in MEFs, most of which were similarly occupied by the RAR alpha and RAR gamma receptors. Only a subset of the genes associated with these loci are regulated by RA, among which are several critical components of the TGF-beta pathway. We also show RAR binding to a novel series of target genes involved in cell cycle regulation, transformation, and metastasis, suggesting new pathways by which RA may regulate proliferation and cancer. Few of the RAR binding loci contained consensus direct-repeat (DR)-type elements. The majority comprised either degenerate DRs or no identifiable DRs but anomalously spaced half sites. Furthermore, we identify 462 RAR target loci in embryonic stem (ES) cells and show that their occupancy is cell type specific. Our results also show that differences in the chromatin landscape regulate the accessibility of a subset of more than 700 identified loci to RARs, thus modulating the repertoire of target genes that can be regulated and the biological effects of RA.
Subject(s)
Embryonic Stem Cells/metabolism , Fibroblasts/metabolism , Receptors, Retinoic Acid/metabolism , Amino Acid Motifs , Animals , Binding Sites , Cells, Cultured , Chromatin Immunoprecipitation , Gene Expression Profiling , Gene Expression Regulation , Mice , Oligonucleotide Array Sequence Analysis , Retinoic Acid Receptor alpha , Transcription Factor TFIID/genetics , Transcription Factors/metabolism , Retinoic Acid Receptor gammaABSTRACT
Bacteria from the exit site of dialysis catheter can grow into microcolonies in biofilm. It has been hypothesized that rifampin-protamine combination may have an effect on the biofilm. In hemodialysis centre a combination of rifampin mixed with protamine is commonly used in some centre in order to prevent catheter related infections in hemodialysis patients. Therefore, a pharmaceutical assessment of the rifampin-protamine mixture is clearly mandatory. The aim of this study is to evaluate the stability and the sterility of the rifampin-protamine solution. Five milliliters of protamine (10 mg) was mixed with 10 mL of Rifampin (600 mg). The solution was kept at -20 degrees C temperature for two weeks and subsequently at 4 degrees C for two additional weeks. Stability and sterility were evaluated the first day and two weeks, three weeks and four weeks after the preparation. Concentration of rifampin in the solution was assessed by HPLC. Protamine concentration was evaluated by the effect of the solution on the heparin activity of a heparinized plasma. The solution was cultured on broth media and mannitol agar plate. Areas under curve of rifampin were similar between the four different evaluations. The effect of the solution on the heparin activity was comparable at the four different evaluations. Our results demonstrate the stability and the compatibility of the solution. However, there was biological interference between broth media and the solution. It was, therefore, impossible to make any conclusion after broth culture. Culture on mannitol agar plate did not show any microbiological growth. Based on this finding, we recommend preparing the rifampin-protamine combination in individual conditioning at the time of the utilization.