Project description:Transcriptome analysis of RNA samples from riboflavin-depleted HEK293T cells. Riboflavin is an essential component of the human diet and its derivative cofactors have an established role in oxidative metabolism. Riboflavin deficiency has been linked with various human diseases. In this study, we have modelled riboflavin deficiency in HEK293T cell line, shown remarkable increase of cell proliferation. The aim of the present study is to develop a cell culture model of riboflavin depletion and analyze its molecular mechanism of acceleration cell proliferation. So, we used Affymetrix Human Transcriptome Array 2.0 to identify genes that were differentially expressed upon riboflavin-depleted HEK293T cells.
Project description:Microarray analysis has been applied to the cell proliferation in a human colonic cel line, Caco-2. We have shown previously that a moderate riboflavin depletion around weaning has a profound impact on the structure and function of the small intestine of the rat, which is not reversible following riboflavin repletion. In this study we have modelled riboflavin deficiency in a human cell line, shown irreversible loss of cell viability associated with impaired mitosis and identified candidate effectors of riboflavin depletion in the cell. The aim of the present study is to develop a cell culture model of riboflavin depletion and analyse its behaviour using a using a combination of cell biology approaches including microarray analysis. A human colonic cell line, Caco-2, was grown in culture and treated to riboflavin depletion. Treated and untreated cells were collected at appropriate time points and isolated RNA subjected to microarray analysis.
Project description:Microarray analysis has been applied to the cell proliferation in a human colonic cel line, Caco-2. We have shown previously that a moderate riboflavin depletion around weaning has a profound impact on the structure and function of the small intestine of the rat, which is not reversible following riboflavin repletion. In this study we have modelled riboflavin deficiency in a human cell line, shown irreversible loss of cell viability associated with impaired mitosis and identified candidate effectors of riboflavin depletion in the cell. The aim of the present study is to develop a cell culture model of riboflavin depletion and analyse its behaviour using a using a combination of cell biology approaches including microarray analysis.
Project description:Protein kinase CK2 is a conserved serine/threonine kinase that participates in various cellular processes. Elevated nuclear expression of CK2α has been observed in human carcinomas, but mechanisms for its variable localization in cells are poorly understood. This study demonstrates a functional connection between nuclear CK2 and gene expression in relation to cell proliferation. Growth stimulation of quiescent human fibroblasts identified a pool of CK2 highly phosphorylated at serine 7 of the α subunit that translocated into the nucleus. This phosphorylation appeared essential for its nuclear localization and catalytic activity. Protein signatures associated with nuclear CK2 complexes revealed enrichment of transcription factors and chromatin remodelers that seemed unique during progression through G1 phase of the cell cycle. Chromatin immunoprecipitation-sequencing profiling demonstrated recruitment of CK2α to the active gene locus, more abundantly in late G1 phase than in early G1. Notably, we confirmed the presence of CK2α at transcriptional start sites of core histone genes, growth stimulus-associated genes, and ribosomal RNAs. This study suggests that nuclear CK2α complexes, uniquely constituted during cell cycle progression, are essential for cell proliferation, by activating histone genes, triggering ribosome biogenesis, and then synthesize the components necessary for cell division, specified in the nucleus and also in the nucleolus.
Project description:Protein kinase CK2 is a conserved serine/threonine kinase that participates in various cellular processes. Elevated nuclear expression of CK2α has been observed in human carcinomas, but mechanisms for its variable localization in cells are poorly understood. This study demonstrates a functional connection between nuclear CK2 and gene expression in relation to cell proliferation. Growth stimulation of quiescent human fibroblasts identified a pool of CK2 highly phosphorylated at serine 7 of the α subunit that translocated into the nucleus. This phosphorylation appeared essential for its nuclear localization and catalytic activity. Protein signatures associated with nuclear CK2 complexes revealed enrichment of transcription factors and chromatin remodelers that seemed unique during progression through G1 phase of the cell cycle. Chromatin immunoprecipitation-sequencing profiling demonstrated recruitment of CK2α to the active gene locus, more abundantly in late G1 phase than in early G1. Notably, we confirmed the presence of CK2α at transcriptional start sites of core histone genes, growth stimulus-associated genes, and ribosomal RNAs. This study suggests that nuclear CK2α complexes, uniquely constituted during cell cycle progression, are essential for cell proliferation, by activating histone genes, triggering ribosome biogenesis, and then synthesize the components necessary for cell division, specified in the nucleus and also in the nucleolus.
Project description:Transcriptome analysis of control and MALAT1 lncRNA-depleted RNA samples from human diploid lung fibroblasts [WI38] The long noncoding MALAT1 RNA is upregulated in cancer tissues and its elevated expression is associated with hyper-proliferation, but the underlying mechanism is poorly understood. We demonstrate that MALAT1 levels are regulated during normal cell cycle progression. Genome-wide transcriptome analyses in normal human diploid fibroblasts reveal that MALAT1 modulates the expression of cell cycle genes, and is required for G1/S and mitotic progression. Depletion of MALAT1 leads to activation of p53 and its target genes. The cell cycle defects observed in MALAT1-depleted cells are sensitive to p53 levels, indicating that p53 is a major downstream mediator of MALAT1 activity. Furthermore, MALAT1-depleted cells display reduced expression of B-MYB (Mybl2), an oncogenic transcription factor involved in G2/M progression, due to altered binding of splicing factors on B-MYB pre-mRNA and aberrant alternative splicing. In human cells, MALAT1 promotes cellular proliferation by modulating the expression and/or pre-mRNA processing of cell cycle-regulated transcription factors. These findings provide mechanistic insights on the role of MALAT1 in regulating cellular proliferation. We analyzed RNA from control and MALAT1 depleted WI38 cells using the Affymetrix Human Exon 1.0 ST platform. Array data was analyzed by Partek Genomic Suite software.
Project description:Zinc finger proteins are a large family of DNA-binding factors that play key roles in diverse cellular processes including gene regulation, RNA metabolism and cell cycle control. The zinc finger protein ZNF512B has recently been implicated in chromatin organization and transcriptional repression through its direct interaction with the nucleosome remodeling and deacetylase (NuRD) complex, its DNA-binding ability, and its association with the histone variant H2A.Z. Here, we uncover a previously unrecognized role for ZNF512B that is independent of both its zinc finger domains and NuRD association. We identify ZNF512B as a spindle-associated factor that regulates progression through mitosis, specifically controlling metaphase exit. ZNF512B’s N-terminal internal region, which contains 25 repeats of a six-residue motif predicted to form a β-helix structure, is required and sufficient for its spindle interaction. Elevated ZNF512B levels result in a profound metaphase arrest that is ultimately lethal, a phenotype arising from the combined activity of its spindle-binding and chromatin-tethering functions. Conversely, ZNF512B depletion accelerates stem cell proliferation, impairs differentiation, and upregulates genes linked to cell cycle progression. Our findings position ZNF512B as a multifunctional protein that acts as a transcriptional repressor, a chromatin aggregator and a novel metaphase exit regulator through spindle fiber binding.