The thiazolidinedione (TZD) family of PPARgamma agonists, especially troglitazone and ciglitazone, induce cell cycle arrest, differentiation, and apoptosis in cancer cells. Mounting evidence indicates that TZDs interfere with multiple signaling mechanisms independently of PPARgamma activation, which affect many aspects of cellular functions governing cell cycle progression and survival of cancer ...

For many decades after its initial characterization, heterochromatin was considered to be transcriptionally inert, but newer work indicates that this highly condensed chromosomal material is transcribed, and rapidly silenced, by an orchestrated sequence of events directed by RNA interference (RNAi). Recent studies shed light on the timely assembly and inheritance ...

MicroRNAs (miRNAs) have attracted considerable attention because of their important roles in development, normal physiology, and disease states including cancer. Recent studies have identified specific miRNAs that regulate the cell cycle and have documented that the loss or gain of miRNA-mediated cell-cycle control contributes to malignancy. miRNAs regulate classic cell-cycle ...

In contrast to animal growth, plant growth is largely post-embryonic. Therefore plants have developed new mechanisms to precisely regulate cell proliferation by means of internal and external stimuli whilst the general core cell cycle machinery is conserved between eukaryotes. In this work we demonstrate a role for the Arabidopsis thaliana ...

The Myc-associated zinc-finger protein, Miz1, is a negative regulator of cell proliferation and induces expression of the cell-cycle inhibitors p15(Ink4b) and p21(Cip1). Here we identify the ribosomal protein L23 as a negative regulator of Miz1-dependent transactivation. L23 exerts this function by retaining nucleophosmin, an essential co-activator of Miz1 required for ...

Budding yeast Saccharoymyces cerevisiae is a powerful model system for analyzing eukaryotic cell cycle regulation. Yeast cell cycle analysis is typically performed by visual analysis or flow cytometry, and both have limitations in the scope and accuracy of data obtained. This study demonstrates how multispectral imaging flow cytometry (MIFC) provides ...

A dielectric technique has been developed for monitoring of cell cycle progression in synchronized culture, which would be a promising tool for cell cycle analysis in cell biology and biotechnology.

The mechanisms by which quiescent cells, including adult stem cells, preserve their ability to resume proliferation after weeks or even years of cell cycle arrest are not known. We report that reversibility is not a passive property of nondividing cells, because enforced cell cycle arrest for a period as brief ...

The aim of this study was to investigate the effects of 3 root canal sealers on the cell cycle of mouse fibroblasts (3T3 cell line). Freshly mixed root canal sealers (AH Plus, Endofill, and Sealer 26) were eluted for 24 h using cell culture medium. Antiproliferation activity of different eluate ...

The cell cycle transcriptional program imposes order on events of the cell-cycle and is a target for signals that regulate cell-cycle progression, including checkpoints required to maintain genome integrity. Neither the mechanism nor functional significance of checkpoint regulation of the cell-cycle transcription program are established. We show that Nrm1, an ...

The mechanism of DNA replication is highly conserved in eukaryotes, with the process being preceded by the ordered assembly of pre-replication complexes (pre-RCs). Pre-RC formation is triggered by the association of the origin replication complex (ORC) with chromatin. Leishmania major appears to have only one ORC ortholog, ORC1. ORC1 in ...

2-Methoxyestradiol (2-ME), a naturally occurring mammalian metabolite of 17beta-Estradiol (E2), induces cell death in osteosarcoma cells. To further understand the molecular mechanisms of action, we have investigated cell cycle progression in 2-ME-treated human osteosarcoma (MG63, SaOS-2 and LM7 [corrected]) cells. At 5 microM, 2-ME induced growth arrest by inducing a ...

The Myc-associated zinc-finger protein, Miz1, is a negative regulator of cell proliferation and induces expression of the cell-cycle inhibitors p15(Ink4b) and p21(Cip1). Here we identify the ribosomal protein L23 as a negative regulator of Miz1-dependent transactivation. L23 exerts this function by retaining nucleophosmin, an essential co-activator of Miz1 required for ...

Mitochondrial complex II defect has recently been implicated in cellular senescence and in the ageing process of which a critical phenotype is retardation and arrest of cellular growth. However, the underlying mechanisms of how complex II defect affects cellular growth, remain unclear. In this study, we investigated the effect of ...

Although the cycling of eukaryotic cells has long been a primary focus for cancer therapeutics, recent advances in imaging and data analysis allow even further definition of cellular events as they occur in individual cells and cellular subpopulations in response to treatment. High-content imaging (HCI) has been an effective tool ...

B cells are induced to enter the cell cycle by stimuli including ligation of the B-cell receptor (BCR) complex and Toll-like receptor (TLR) agonists. This review discusses the contribution of several molecules, which act at distinct steps in B-cell activation. The adapter molecule Bam32 (B-lymphocyte adapter of 32 kDa) helps ...

In this study, we show that depletion of Chk1 by small interfering RNA (siRNA) results in failure of reentry to the cell cycle after DNA replication has been stalled by exposure to hydroxyurea (HU). Casein kinase II (CKII) is degraded in these cells in a proteasome-dependent manner, resulting in decreased ...

The infectious cycle of human cytomegalovirus (HCMV) is intricately linked to the host's cell cycle. Viral gene expression can be initiated only in G(0)/G(1) phase. Once expressed, the immediate-early gene product IE2 prevents cellular DNA synthesis, arresting infected cells with a G(1) DNA content. This function is required for efficient ...

The flexibility displayed by apicomplexan parasites to vary their mode of replication has intrigued biologists since their discovery by electron microscopy in the 1960s and 1970s. Starting in the 1990s we began to understand the cell biology of the cytoskeleton elements driving cytokinesis. By contrast, the molecular mechanisms that regulate ...

High-risk human papillomaviruses (HPV) cause cervical cancer. The biological properties of HPV-45, the third most prevalent high-risk HPV-genotype, are unknown. We demonstrate here that the HPV-45 E7 protein transforms immortalized NIH3T3 fibroblasts, while mutations in either the conserved LXCXE sequence (C28G) or the carboxyl-terminus (Delta87LQQLF91) significantly abolish this activity. To ...

Mutations in PTPN11, which encodes the protein tyrosine phosphatase Shp2, are commonly found in juvenile myelomonocytic leukemia (JMML). We hypothesized that PTPN11 mutations promote cell-cycle progression and confer enhanced survival to hematopoietic progenitors. Murine bone marrow low-density mononuclear cells were transduced with pMIEG3, pMIEG3-WT Shp2, pMIEG3-Shp2D61Y, or pMIEG3-Shp2E76K followed by ...

In a recent issue of Molecular Cell, Hong et al. (2008) describe an alternative mechanism by which mTOR promotes cell-cycle progression; it phosphorylates and activates SGK, which in turn phosphorylates the cell-cycle inhibitor p27, promoting its cytoplasmic retention.

Elegant work by others has highlighted the importance of connections between polar growth and cell cycle regulation in budding and fission yeast. However, it is striking that little attention has been paid to the study of these connections in phytopathogenic fungi. In these crop pests, germination of spores, the main ...

Deregulation of cell cycle leads to cell transformation and cancer development. Here we present profiling the proteome dynamics using 2-DE and constructing the associated functional networks during the cell cycle of human hepatoma cells, Mahlavu. The protein dynamics was validated by hierarchical clustering analysis on the proteome, and by Northern ...

Numerous reports correlate nitric oxide (NO) production with stalled S-phase progression, but the molecular mechanism(s) of cell cycle arrest remains elusive. Paradoxically numerous human tumors are exposed to vast quantities of nitric oxide and its reactive byproducts in situ, yet they continue to grow and proliferate. The dual-specificity phosphatase Cdc25A ...

Cyclin-dependent kinase 5 (Cdk5) is a nontraditional Cdk that is primarily active in postmitotic neurons. Its best known substrates are cytoskeletal proteins. Less appreciated is its role in the maintenance of a postmitotic state. We show here that in cycling cells (NIH 3T3), the localization of Cdk5 changes from predominantly ...

The mammalian oviduct plays a crucial role in events leading to the establishment of pregnancy. During the reproductive cycle, the reproductive system undergoes various changes, including alterations in the number of different cell types in the oviductal epithelium and changes in the height of oviductal cells. Maintaining the unique oviductal ...

Resveratrol may function as a cancer chemopreventive agent. However, few data are available on the antitumoral activities of its dimer, epsilon-viniferin, also present in human diet. So, the effects of resveratrol, epsilon-viniferin, of their acetylated forms (resveratrol triacetate, epsilon-viniferin pentaacetate) and of vineatrol (a wine grape extract) were compared on ...

Cells from the new Nexelion battery from Sony Corporation were tested for capacity, low temperature performance, high power capability, high temperature storage, rapid recharge and cycle life on deep discharge. The Nexelion 14430 size cells were found to perform equal or better to conventional size 14430 cells in all areas ...

To accurately observe high-frequency events during transient cell cycle kinetics, we have implemented a single step 15-min DNA staining protocol using automated flow cytometry. This protocol was used to sample and to analyze a Chinese hamster ovary cell culture for the DNA distribution, viable cell concentration, apoptotic cell concentration, and ...

The 26S proteasome is responsible for the controlled proteolysis of a vast number of proteins, including crucial cell cycle regulators. Accordingly, in Saccharomyces cerevisiae, 26S proteasome function is mandatory for cell cycle progression. In budding yeast, the 26S proteasome is assembled in the nucleus, where it is localized throughout the ...

Mental retardation, the hallmark of Down syndrome (DS), has been attributed to the reduced number of neurons populating the DS brain. The Ts65Dn mouse model of DS displays several anomalies analogous to those in individuals with DS, including neurogenesis impairment. The goal of the current study was to determine whether ...

In Xenopus embryos, the cell cycle is driven by an autonomous biochemical oscillator that controls the periodic activation and inactivation of cyclin B1-CDK1. The oscillator circuit includes a system of three interlinked positive and double-negative feedback loops (CDK1 -> Cdc25 -> CDK1; CDK1 -/ Wee1 -/ CDK1; and CDK1 -/ ...

Cell division, differentiation and morphogenesis are coordinated during embryonic development, and frequently are in disarray in pathologies such as cancer. Here, we present a zebrafish mutant that ceases mitosis at the beginning of gastrulation, but that undergoes axis elongation and develops blood, muscle and a beating heart. We identify the ...

Cell cycle arrest of malignant cells is an important option for cancer treatment. In this study, we modified the structure of antimitotic 2-phenylindole-3-carbaldehydes by condensation with hydrazides of various benzoic and pyridine carboxylic acids. The resulting hydrazones inhibited the growth of MDA-MB 231 and MCF-7 breast cancer cells with IC(50) ...

OBJECTIVE: This study was designed to evaluate a cell proliferation marker, including the percentage of cycling cells (MIB1), and the duration of the cell cycle (assessed by argyrophilic nucleolar organizer regions proteins [AgNORs] measurement). STUDY DESIGN: We included 90 patients with invasive node-negative breast cancer. None received chemotherapy. With the ...

We have shown previously that beta-catenin and cyclin D1 are up-regulated in cortical neurons from homozygous mice carrying the familial Alzheimer's disease (FAD) presenilin-1 M146V mutation in a knock-in model (PS1 KI(M146V) mice), leading to cell cycle-associated apoptosis. Here, we have aimed to determine (i) whether this phenotype is present ...

The female sex steroid hormone oestrogen stimulates both cell proliferation and cell differentiation in target tissues. These biological actions are mediated primarily through nuclear oestrogen receptors (ERs). The ligand-dependent transactivation of ERs requires several nuclear co-regulator complexes; however, the cell-cycle-dependent associations of these complexes are poorly understood. By using a ...

Oxidative stress is known to play a key role in the progression of liver disease, including non-alcoholic steatohepatitis (NASH), which is often accompanied by hyperglycemia. This study examined the influence of high glucose on oxidative stress-induced hepatic cell death. Hc cells, a normal human hepatocyte-derived cell line, were cultured in ...

Autophagy is a key mechanism for cell survival under conditions of nutrient limitation. On the organismal level, autophagy is essential for survival of lower eukaryotes during extended periods of starvation, and it is induced in mammals during short-term starvation. As a consequence of the induction of autophagy during short periods ...

Trypanosoma brucei has two DNA compartments: the nucleus and the kinetoplast. DNA replication of these two compartments only partially coincides. Woodward and Gull [Woodward R, Gull K. Timing of nuclear and kinetoplast DNA replication and early morphological events in the cell cycle of Trypanosoma brucei. J Cell Sci 1990;95:49-57] comprehensively ...

Mutations in ATM (Ataxia telangiectasia mutated) result in Ataxia telangiectasia (A-T), a disorder characterized by progressive neurodegeneration. Despite advances in understanding how ATM signals cell cycle arrest, DNA repair, and apoptosis in response to DNA damage, it remains unclear why loss of ATM causes degeneration of post-mitotic neurons and why ...

Biological functions governed by the circadian clock are the evident result of the entrainment operated by the earth's day and night cycle on living organisms. However, the circadian clock is not unique, and cells and organisms possess many other cyclic activities. These activities are difficult to observe if carried out ...

The finding of a genome-wide oscillation in transcription that gates cells into S phase and coordinates mitochondrial and metabolic functions has altered our understanding of how the cell cycle is timed and how stable cellular phenotypes are maintained. Here we present the evidence and arguments in support of the idea ...

FoxO transcription factors are an evolutionary conserved subfamily of the forkhead transcription factors, characterized by the forkhead DNA-binding domain. FoxO factors regulate a number of cellular processes involved in cell-fate decisions in a cell-type- and environment-specific manner, including metabolism, differentiation, apoptosis and proliferation. A key mechanism by which FoxO determines ...

The control of growth of lymphocyte populations is crucial to the physiological regulation of the immune system, and to the prevention of both leukaemic and autoimmune disease. This control is mediated through modulation of the cell cycle and regulation of cell death. During log-phase growth the rate of proliferation is ...

Proliferating cell nuclear antigen (PCNA) is a homotrimeric ring-shaped protein that encircles the DNA and acts as a stationary loading platform for multiple, transiently interacting partners participating in various DNA transactions. This essential cellular component, originally characterized as a nuclear antigen of dividing cells, is evolutionary highly conserved from yeast ...

When cell cycle studies are performed following cell cycle synchronization, it is possible that critical properties of an actively cycling cell will be overlooked. For this reason past studies have not revealed critical aspects of cell cycle control; such as how a cell determines when to exit the cell cycle, ...

Macrophage immigration inhibitory factor (MIF) is a ubiquitously expressed proinflammatory mediator that has also been implicated in cell growth, cell cycle and carcinogenesis. In this study, we demonstrate siRNA-mediated knockdown of MIF results in G(0)/G(1) cell cycle arrest in HEK293 cells. To elucidate the molecular mechanism of cell cycle perturbation ...

DNA damage response recruits complex molecular machinery involved in DNA repair, arrest of cell cycle progression, and potentially in activation of apoptotic pathway. Among the first responders is the Mre11- (MRN) complex of proteins (Mre11, Rad50, Nbs1), essential for activation of ATM; the latter activates checkpoint kinase 2 (Chk2) and ...