The Birt-Hogg-Dube disease occurs as a result of germline mutations in the human Folliculin gene (FLCN), and is characterized by clinical features including fibrofolliculomas, lung cysts and multifocal renal neoplasia. Clinical and genetic evidence suggest that FLCN acts as a tumor suppressor gene. The human cell line UOK257, derived from the renal cell carcinoma of a patient with a germline mutation in the FLCN gene, harbors a truncated version of the FLCN protein. Reconstitution of the wild type FLCN protein into UOK257 cells delays cell cycle progression, due to a slower progression through the late S and G2/M-phases. Similarly, Flcn-/- mouse embryonic fibroblasts progress more rapidly through the cell cycle than wild type controls (Flcnflox/flox). The reintroduction of tumor-associated FLCN mutants (FLCN DF157, FLCN 1-469 or FLCN K508R) fails to delay cell cycle progression in UOK257 cells. Additionally, FLCN phosphorylation (on Serines 62 and 73) fluctuates throughout the cell cycle and ...
The retinoblastoma protein: Rb) inhibits both cell division and apoptosis, but the mechanism by which Rb alternatively regulates these divergent outcomes remains poorly understood. Cyclin dependent kinases: Cdks) promote cell division by phosphorylating and reversibly inactivating Rb by a hierarchical series of phosphorylation events and sequential conformational changes. The stress-regulated mitogen activated protein kinase: MAPK) p38 also phosphorylates Rb, but it does so in a cell cycle-independent manner that is associated with apoptosis rather than with cell division. Here, we show that p38 phosphorylates Rb by a novel mechanism that is distinct from that of Cdks. p38 bypasses the cell cycle-associated hierarchical phosphorylation and directly phosphorylates Rb on Ser567, which is not phosphorylated during the normal cell cycle. Phosphorylation by p38, but not Cdks, triggers an interaction between Rb and the human homologue of murine double minute 2: Hdm2), leading to degradation of Rb, release of
Rice (Oryza sativa L.) as a model and crop plant with a sequenced genome offers an outstanding experimental system for discovering and functionally analyzing the major cell cycle control elements in a cereal species. In this study, we identified the core cell cycle genes in the rice genome through a hidden Markov model search and multiple alignments supported with the use of short protein sequence probes. In total we present 55 rice putative cell cycle genes with locus identity, chromosomal location, approximate chromosome position and EST accession number. These cell cycle genes include nine cyclin dependent-kinase (CDK) genes, 27 cyclin genes, one CKS gene, two RBR genes, nine E2F/DP/DEL genes, six KRP genes, and one WEE gene. We also provide characteristic protein sequence signatures encoded by CDK and cyclin gene variants. Promoter analysis by the FootPrinter program discovered several motifs in the regulatory region of the core cell cycle genes. As a first step towards functional ...
TY - JOUR. T1 - High-resolution timing of cell cycle-regulated gene expression. AU - Rowicka-Kudlicka, Malgorzata. AU - Kudlicki, Andrzej. AU - Tu, Benjamin P.. AU - Otwinowski, Zbyszek. PY - 2007/10/23. Y1 - 2007/10/23. N2 - The eukaryotic cell division cycle depends on an intricate sequence of transcriptional events. Using an algorithm based on maximum-entropy deconvolution, and expression data from a highly synchronized yeast culture, we have timed the peaks of expression of transcriptionally regulated cell cycle genes to an accuracy of 2 min (≈1% of the cell cycle time). The set of 1,129 cell cycle-regulated genes was identified by a comprehensive analysis encompassing all available cell cycle yeast data sets. Our results reveal distinct subphases of the cell cycle undetectable by morphological observation, as well as the precise timeline of macromolecular complex assembly during key cell cycle events.. AB - The eukaryotic cell division cycle depends on an intricate sequence of ...
Retinoids have antiproliferative effects in human breast cancer cells and share some characteristics with antiestrogens, although the molecular targets involved have yet to be identified in either case. Using T-47D human breast cancer cells, we compared the effects of retinoic acid (RA) and the antiestrogen ICI 164384 on cell cycle phase distribution and the expression of genes with known functions in cell cycle control. Both RA and ICI 164384 inhibited cell cycle progression in G1 phase, but the RA effect was delayed by 16 h. This delay in action was also seen with 9-cis RA and other retinoids. Administration of 17 beta-estradiol abolished the effects of ICI 164384 but was without effect in RA-treated cells. Antiestrogen treatment caused a rapid inhibition of c-myc and cyclin D1 gene expression and reduced Cdk2 activity by more than 50% at 24 h. RA, however, did not affect c-myc or cyclin D1 gene expression, nor did it significantly change the mRNA or protein levels of cyclins D3 or E or cyclin
Combinations of gemcitabine and trabectedin exert modest synergistic cytotoxic effects on two pancreatic cancer cell lines. Here, systems pharmacodynamic (PD) models that integrate cellular response data and extend a prototype model framework were developed to characterize dynamic changes in cell cycle phase of cancer cell subpopulations in response to gemcitabine and trabectedin as single agents and in combination. Extensive experimental data were obtained for two pancreatic cancer cell lines (MiaPaCa-2 and BxPC-3), including cell proliferation rates over 0-120 h of drug exposure, and the fraction of cells in different cell cycle phases or apoptosis. Cell cycle analysis demonstrated that gemcitabine induced cell cycle arrest in S phase, and trabectedin induced transient cell cycle arrest in S phase that progressed to G2/M phase. Over time, cells in the control group accumulated in G0/G1 phase. Systems cell cycle models were developed based on observed mechanisms and were used to characterize both cell
The cell cycle includes 4 main phases: Gap 1 (G1), DNA replication (S), Gap 2 (G2), and mitosis (M). Tight regulation of the transition between these phases halts cell cycle progression if a phase is not properly completed. For example, the G2-M DNA damage checkpoint ensures the fidelity of DNA replication, and arrests the cell cycle to allow time for replication error correction and DNA damage repair. Cell cycle progression is regulated by the cyclic rise and fall of kinase expression, and their interaction with, and action on, their cyclin targets. Cell cycle dysregulation commonly occurs during oncogenesis, and tumor cells often do not arrest the cell cycle when normally required. Key genes that regulate cell cycle progression and checkpoints encode cullins, cyclins, and cyclin-dependent kinases and their inhibitors. Other cell cycle regulatory genes include apoptosis regulators and DNA damage sensors ...
TY - CHAP. T1 - Myocardial regeneration via cell cycle activation. AU - LaFontant, Pascal J.. AU - Field, Loren J.. PY - 2007/1/1. Y1 - 2007/1/1. N2 - Introduction During development, increases in heart size results as a consequence of the differentiation and proliferation of cardiomyocytes, neurons, interstitial cells, and components of the vasculature. At birth, cardiomyocytes undergo a gradual transition from hyperplastic to hypertrophic growth, such that subsequent increases in myocardial mass result largely from increased myocyte size rather than increased number. In contrast, the other cell types present in the heart retain the ability to proliferate. Consequently, in adults, although cardiomyocytes constitute approximately 90% of the mass of the heart, they constitute less than 20% of the total number of cells present.. AB - Introduction During development, increases in heart size results as a consequence of the differentiation and proliferation of cardiomyocytes, neurons, interstitial ...
Pluripotency and the capability for self-renewal are essential characteristics of human embryonic stem cells (hESCs), which hold great potential as a cellular source for tissue replacement. Short cell cycle (15-16 h) compared to somatic cells is another property of hESCs. Efficient synchronization of hESCs at different cell cycle stages is important to elucidate the mechanistic link between cell cycle regulation and cell fate decision. This protocol describes how to establish synchronization of hESCs at different cell cycle stages.
TY - JOUR. T1 - A cell cycle study of the effects of Con A on synchronized mouse embryo fibroblasts. T2 - Arrest and dissociation between uptake of thymidine and DNA synthesis. AU - Mallucci, L.. AU - Dunn, M.. AU - Wells, V.. AU - Delia, D.. PY - 1980. Y1 - 1980. N2 - We have examined the effects of 50 μg ml-1 of Con A added to synchronized mouse embryo fibroblasts at different times during the cell cycle. We found that Con A caused arrest of growth not solely by preventing G1-G0 cells from entering the S-phase but also by exerting a G2 block. We also found that Con A, which prevented commencement of S-phase, did not arrest cells already in S from reaching the G2 stage but inhibited the S-phase associated process of thymidine uptake. The inhibition was greater when the Con A receptors were extensively clustered.. AB - We have examined the effects of 50 μg ml-1 of Con A added to synchronized mouse embryo fibroblasts at different times during the cell cycle. We found that Con A caused arrest of ...
Time-course microarray experiments have been widely used to identify cell cycle regulated genes. However, the method is not effective for lowly expressed genes and is sensitive to experimental conditions. To complement microarray experiments, we propose a computational method to predict cell cycle regulated genes based on their genomic features - transcription factor binding and motif profiles. Through integrating gene-expression data with ChIP-chip binding and putative binding sites of transcription factors, our method shows high accuracy in discriminating yeast cell cycle regulated genes from non-cell cycle regulated ones. We predict 211 novel cell cycle regulated genes. Our model rediscovers the main cell cycle transcription factors and provides new insights into the regulatory mechanisms. The model also reveals a regulatory circuit mediated by a number of key cell cycle regulators. Our model suggests that the periodical pattern of cell cycle genes is largely coded in their promoter regions, which
PURPOSE The cell cycle progression test is a validated molecular assay that assesses prostate cancer specific disease progression and mortality risk when combined with clinicopathological parameters. We present the results from PROCEDE-1000, a large, prospective registry designed to evaluate the impact of the cell cycle progression test on shared treatment decision making for patients newly diagnosed with prostate cancer. MATERIALS AND METHODS Untreated patients with newly diagnosed prostate adenocarcinoma were enrolled in the study and the cell cycle progression test was performed on the initial prostate biopsy tissue. A set of 4 sequential surveys tracked changes relative to initial therapy recommendations (before cell cycle progression) based on clinicopathological parameters following physician review of the cell cycle progression test result, physician/patient review of the cell cycle progression test results and a minimum of 3 months of clinical followup (actual treatment). RESULTS Of the 1
Cell Growth and Reproduction Study Guide The Cell Cycle Study Guide Vocabulary - Cell Cycle, Mitosis, Cytokinesis 1. How did the G1 and G2 stages get their
Geminiviruses are small DNA viruses that use plant replication machinery to amplify their genomes. Microarray analysis of the Arabidopsis (Arabidopsis thaliana) transcriptome in response to cabbage leaf curl virus (CaLCuV) infection uncovered 5,365 genes (false discovery rate ,0.005) differentially expressed in infected rosette leaves at 12 d postinoculation. Data mining revealed that CaLCuV triggers a pathogen response via the salicylic acid pathway and induces expression of genes involved in programmed cell death, genotoxic stress, and DNA repair. CaLCuV also altered expression of cell cycle-associated genes, preferentially activating genes expressed during S and G2 and inhibiting genes active in G1 and M. A limited set of core cell cycle genes associated with cell cycle reentry, late G1, S, and early G2 had increased RNA levels, while core cell cycle genes linked to early G1 and late G2 had reduced transcripts. Fluorescence-activated cell sorting of nuclei from infected leaves revealed a ...
Distinct patterns of histone methylation during human cell cycle progression are described. Histone H4 methyltransferase activity is cell cycle-regulated, consistent with increased H4 Lys 20 methylation at mitosis. This increase closely follows the cell cycle-regulated expression of the H4 Lys 20 methyltransferase, PR-Set7. Localization of PR-Set7 to mitotic chromosomes and subsequent increase in H4 Lys 20 methylation were inversely correlated to transient H4 Lys 16 acetylation in early S-phase. These data suggest that H4 Lys 20 methylation by PR-Set7 during mitosis acts to antagonize H4 Lys 16 acetylation and to establish a mechanism by which this mark is epigenetically transmitted (Rice, 2002). To determine histone methyltransferase activity during the human cell cycle, HeLa cells were arrested by treatment with thymidine followed by mimosine. Every 2.5 h following release from the G1 arrest, synchronized cells were isolated for analysis, and the cell cycle phase was determined by ...
Despite traditionally regarded as identical, cells in a microbial cultivation present a distribution of phenotypic traits, forming a heterogeneous cell population. Moreover, the degree of heterogeneity is notably enhanced by changes in micro-environmental conditions. A major development in experimental single-cell studies has taken place in the last decades. It has however not been fully accompanied by similar contributions within data analysis and mathematical modeling. Indeed, literature reporting, for example, quantitative analyses of experimental single-cell observations and validation of model predictions for cell property distributions against experimental data is scarce. This study focuses on the experimental and mathematical description of the dynamics of cell size and cell cycle position distributions, of a population of Saccharomyces cerevisiae, in response to the substrate consumption observed during batch cultivation. The good agreement between the proposed multi-scale model (a ...
NADPH oxidase 2 (Nox2)-derived oxidative stress and redox-signalling have been found to play an important role in hyperglycaemia-induced endothelial dysfunction in diabetes. Acetate (NaA) is a member of the short chain fatty acids (SCFA) family which acts through G-protein coupled receptor 43 (GPCR43) to exert anti-inflammatory effects and to increase insulin sensitivity. However, its action in endothelial cells remains unknown. In this study we investigated the effects of NaA and GPCR43 on high glucose (30 mM, 24 h)-induced Nox2 activation and endothelial cell cycle progression using human pulmonary microvascular endothelial cells (HPMECs). Compared to control cells, high glucose increased significantly i) Nox2-derived superoxide production (48.5±12.6%) as detected by both lucigenin (5 µM)-chemiluminescence and DHE fluorescence; ii) expression of cyclin D, A and E and cell cycle progression from G0/G1 to S and G2/M phases and iii) cell apoptosis (30.66±8.3%) (all p,0.05). These high-glucose ...
The neocortex is patterned in layers of neurons that are generated in an orderly sequence during development. This correlation between cell birthday and laminar fate prompted an examination of how neuronal phenotypes are determined in the developing cortex. At various times after labeling with [3H]thymidine, embryonic progenitor cells were transplanted into older host brains. The laminar fate of transplanted neurons correlates with the position of their progenitors in the cell cycle at the time of transplantation. Daughters of cells transplanted in S-phase migrate to layer 2/3, as do host neurons. Progenitors transplanted later in the cell cycle, however, produce daughters that are committed to their normal, deep-layer fates. Thus, environmental factors are important determinants of laminar fate, but embryonic progenitors undergo cyclical changes in their ability to respond to such cues. ...
For many organisms, the first goal of embryogenesis is to accumulate a large cell population to accommodate gastrulation. To achieve this quickly, embryos employ specialized cell cycles called cleavages that consist of continuous rounds of DNA replication and division. Cell proliferation occurs rapidly because cleavage cycles lack the gap phases and cell cycle checkpoints found in canonical cell cycles. Further, the genetic materials required to sustain cleavage cycles are preloaded during oogenesis, aiding efficient cell cycle progression. After a constant, organism-specific number of cleavages, many metazoan embryos undergo the mid-blastula transition (MBT), which initiates extensive cell cycle remodeling. Cell cycles lengthen, gap phases appear and checkpoint function is acquired. At the same time, the nearly quiescent zygotic genome is activated and transcriptional activity dramatically increases. This dissertation describes how these simultaneous MBT events are regulated. Chapter 2 addresses how
CYCD3;1 expression in Arabidopsis is associated with proliferating tissues such as meristems and developing leaves but not with differentiated tissues. Constitutive overexpression of CYCD3;1 increases CYCD3;1-associated kinase activity and reduces the proportion of cells in the G1-phase of the cell cycle. Moreover, CYCD3;1 overexpression leads to striking alterations in development. Leaf architecture in overexpressing plants is altered radically, with a failure to develop distinct spongy and palisade mesophyll layers. Associated with this, we observe hyperproliferation of leaf cells; in particular, the epidermis consists of large numbers of small, incompletely differentiated polygonal cells. Endoreduplication, a marker for differentiated cells that have exited from the mitotic cell cycle, is inhibited strongly in CYCD3;1-overexpressing plants. Transcript analysis reveals an activation of putative compensatory mechanisms upon CYCD3;1 overexpression or subsequent cell cycle activation. These ...
Cell proliferation is essential for many key processes that occur during development including organogenesis, tissue renewal and germline formation. (Bartkova et al., 1997; Clurman and Roberts, 1995; Pines, 1995; Sandhu and Slingerland, 2000). Therefore, the timing of cell division and differentiation must be precisely coordinated with signals that specify morphogenesis, patterning and growth in a temporal, positional and cell type-specific manner (reviewed by Vidwans and Su, 2001). This coordination is executed through regulating both positive and negative regulatory components of the basal cell cycle machinery.. The cell cycle machinery is well conserved among eukaryotes and complex mechanisms ensure that cell cycle progression occurs in a timely and precise sequence. Cyclin-dependent kinases (Cdks) drive progression through the different cell cycle phases (reviewed by Nigg, 2001). In yeasts, these catalytic subunits are regulated through their association with stage-specific cyclin regulatory ...
Activation of growth factor receptors by ligand binding initiates a cascade of events leading to cell growth and division. Progression through the cell cycle is controlled by cyclin-dependent protein kinases (Cdks), but the mechanisms that link growth factor signaling to the cell cycle machinery have not been established. We report here that Ras proteins play a key role in integrating mitogenic signals with cell cycle progression through G1. Ras is required for cell cycle progression and activation of both Cdk2 and Cdk4 until approximately 2 h before the G1/S transition, corresponding to the restriction point. Analysis of Cdk-cyclin complexes indicates that Ras signaling is required both for induction of cyclin D1 and for downregulation of the Cdk inhibitor p27KIP1. Constitutive expression of cyclin D1 circumvents the requirement for Ras signaling in cell proliferation, indicating that regulation of cyclin D1 is a critical target of the Ras signaling cascade. ...
TY - JOUR. T1 - Rapamycin blocks IL-2-driven T cell cycle progression while preserving T cell survival. AU - Gonzalez, Juana. AU - Harris, Tom. AU - Childs, Geoffrey. AU - Prystowsky, Michael B.. PY - 2001/1/1. Y1 - 2001/1/1. N2 - Effective cellular immune responses require increases in antigen-specific T lymphocytes; IL-2 drives antigen-stimulated T cell proliferation and is largely responsible for the increases observed. We used microarrays containing ∼9000 mouse cDNAs to study IL-2-induced gene expression. IL-2 induces the expression of genes that regulate cell cycle progression, control cell survival, and increase synthetic and metabolic processes during proliferation. IL-2 also suppresses expression of genes that block cell cycle progression and promote cell death. Rapamycin inhibits IL-2-driven proliferation by downregulating the expression of genes required for key processes required for cell cycle progression. Rapamycin also preserves cell survival by keeping intact the IL-2-induced ...
TY - JOUR. T1 - Cell-size dependent progression of the cell cycle creates homeostasis and flexibility of plant cell size. AU - Jones, Angharad R.. AU - Forero-Vargas, Manuel. AU - Withers, Simon P.. AU - Smith, Richard S.. AU - Traas, Jan. AU - Dewitte, Walter. AU - Murray, James A.H.. PY - 2017/1/1. Y1 - 2017/1/1. N2 - © The Author(s) 2017. Mean cell size at division is generally constant for specific conditions and cell types, but the mechanisms coupling cell growth and cell cycle control with cell size regulation are poorly understood in intact tissues. Here we show that the continuously dividing fields of cells within the shoot apical meristem of Arabidopsis show dynamic regulation of mean cell size dependent on developmental stage, genotype and environmental signals. We show cell size at division and cell cycle length is effectively predicted using a two-stage cell cycle model linking cell growth and two sequential cyclin dependent kinase (CDK) activities, and experimental results concur ...
Cell proliferation is the main driving force for plant growth. Although genome sequence analysis revealed a high number of cell cycle genes in plants, little is known about the molecular complexes steering cell division. In a targeted proteomics approach, we mapped the core complex machinery at the heart of the Arabidopsis thaliana cell cycle control. Besides a central regulatory network of core complexes, we distinguished a peripheral network that links the core machinery to up- and downstream pathways. Over 100 new candidate cell cycle proteins were predicted and an in-depth biological interpretation demonstrated the hypothesis-generating power of the interaction data. The data set provided a comprehensive view on heterodimeric cyclin-dependent kinase (CDK)cyclin complexes in plants. For the first time, inhibitory proteins of plant-specific B-type CDKs were discovered and the anaphase-promoting complex was characterized and extended. Important conclusions were that mitotic A- and B-type ...
TY - JOUR. T1 - The PI3K-Akt-mTOR pathway regulates a oligomer induced neuronal cell cycle events. AU - Bhaskar, Kiran. AU - Miller, Megan. AU - Chludzinski, Alexandra. AU - Herrup, Karl. AU - Zagorski, Michael. AU - Lamb, Bruce T.. PY - 2009/4/13. Y1 - 2009/4/13. N2 - Accumulating evidence suggests that neurons prone to degeneration in Alzheimers Disease (AD) exhibit evidence of re-entry into an aberrant mitotic cell cycle. Our laboratory recently demonstrated that, in a genomic amyloid precursor protein (APP) mouse model of AD (R1.40), neuronal cell cycle events (CCEs) occur in the absence of beta-amyloid (A) deposition and are still dependent upon the amyloidogenic processing of the amyloid precursor protein (APP). These data suggested that soluble A species might play a direct role in the induction of neuronal CCEs. Here, we show that exposure of non-transgenic primary cortical neurons to A oligomers, but not monomers or fibrils, results in the retraction of neuronal processes, and ...
The cell cycle proteins are key regulators of cell cycle progression whose de-regulation is one of the causes of breast cancer. RNA interference (RNAi) is an endogenous mechanism to regulate gene expression and it could serve as the basis of regulating aberrant proteins including cell cycle proteins. Since the delivery of small interfering RNA (siRNA) is a main barrier for implementation of RNAi therapy, we explored the potential of a non-viral delivery system, 2.0 kDa polyethylenimines substituted with linoleic acid and caprylic acid, for this purpose. Using a library of siRNAs against cell cycle proteins, we identified cell division cycle protein 20 (CDC20), a recombinase RAD51, and serine-threonine protein kinase CHEK1 as effective targets for breast cancer therapy, and demonstrated their therapeutic potential in breast cancer MDA-MB-435, MDA-MB-231 and MCF7 cells with respect to another well-studied cell cycle protein, kinesin spindle protein. We also explored the efficacy of dicer-substrate siRNA
In recent years, increasing research has focused on the relationship between cytokines and tumorigenesis. It has been suggested that cytokines may be a new therapeutic option for tumors (16-20). In our experiments, we demonstrated that IFN-λ1 inhibited the growth of gastric carcinoma cells in a concentration-dependent manner. These data suggest that IFN-λ1 may be a potential antitumor agent for the treatment of gastric cancer.. Impaired apoptotic induction and dysregulated cell cycle progression are important factors in cancer development. Accordingly, inhibition of cell cycle regulation is particularly useful in the treatment of cancer. In our in vitro study, we demonstrated the apoptosis-inducing effects of IFN-λ1 in gastric carcinoma cells using PI cell cycle analysis, Annexin V and PI staining as well as activated caspase-3. Our study showed that IFN-λ1 induced G1 phase arrest and apoptosis in the gastric carcinoma cells.. Experimental evidence suggests that apoptosis can be mediated by ...
Tumor cells stably transfected with fluorescent proteins enable scientists to visualize many important aspects of cancer in real time at the single cell level. For example, transfected tumor cells have been visualized either through surgically created chronic-transparent windows or directly through the opened skin of living animals [29]. This intravital imaging provides a powerful tool for observing cancer initiation and progression and evaluating the efficacy of candidate cancer drugs in vivo. On the other hand, assays using tumor cells grown in culture provide reliable information about cancer mechanisms, and are amenable to automated high-throughput screening [16-20]. Using a modified fluorescent indicator of cell cycle progression (Fucci2) and cultured immortalized cells, we investigated the mechanism(s) by which anticancer drugs modulate the cell cycle. While population analysis provided statistical data, time-lapse high-resolution imaging analysis allowed us to explore the processes of ...
Mitotic cell cycle progression is accomplished through a reproducible sequence of events, DNA replication (S phase) and mitosis (M phase) separated temporally by gaps known as G1 and G2 phases. Cyclin-dependent kinases (CDKs) are key regulatory enzymes, each consisting of a catalytic CDK subunit and an activating cyclin subunit. CDKs regulate the cells progression through the phases of the cell cycle by modulating the activity of key substrates. Downstream targets of CDKs include transcription factor E2F and its regulator Rb. Precise activation and inactivation of CDKs at specific points in the cell cycle are required for orderly cell division. Cyclin-CDK inhibitors (CKIs), such as p16Ink4a, p15Ink4b, p27Kip1, and p21Cip1, are involved in the negative regulation of CDK activities, thus providing a pathway through which the cell cycle is negatively regulated. Eukaryotic cells respond to DNA damage by activating signaling pathways that promote cell cycle arrest and DNA repair. In response to DNA ...
Mitotic cell cycle progression is accomplished through a reproducible sequence of events, DNA replication (S phase) and mitosis (M phase) separated temporally by gaps known as G1 and G2 phases. Cyclin-dependent kinases (CDKs) are key regulatory enzymes, each consisting of a catalytic CDK subunit and an activating cyclin subunit. CDKs regulate the cells progression through the phases of the cell cycle by modulating the activity of key substrates. Downstream targets of CDKs include transcription factor E2F and its regulator Rb. Precise activation and inactivation of CDKs at specific points in the cell cycle are required for orderly cell division. Cyclin-CDK inhibitors (CKIs), such as p16Ink4a, p15Ink4b, p27Kip1, and p21Cip1, are involved in the negative regulation of CDK activities, thus providing a pathway through which the cell cycle is negatively regulated. Eukaryotic cells respond to DNA damage by activating signaling pathways that promote cell cycle arrest and DNA repair. In response to DNA ...
Video articles in JoVE about g2 phase include Cell Cycle Analysis in the C. elegans Germline with the Thymidine Analog EdU, Studying Cell Cycle-regulated Gene Expression by Two Complementary Cell Synchronization Protocols, Lineage Tracing and Clonal Analysis in Developing Cerebral Cortex Using Mosaic Analysis with Double Markers (MADM), Analysis of Combinatorial miRNA Treatments to Regulate Cell Cycle and Angiogenesis.
The centromeric histone CENP-A is incorporated at different cell cycle phases during somatic mitosis, meiosis I and meiosis II in Drosophila melanogaster.
What is Cell Cycle Gene? Definition of Cell Cycle Gene. Cell Cycle Gene FAQ. Learn more about Cell Cycle Gene. Cell Cycle Gene facts.
Pluripotency transcription programs by core transcription factors (CTFs) might be reset during M/G1 transition to maintain the pluripotency of embryonic stem cells (ESCs). However, little is known about how CTFs are governed during cell cycle progression. Here, we demonstrate that the regulation of Oct4 by Aurora kinase b (Aurkb)/protein phosphatase 1 (PP1) during the cell cycle is important for resetting Oct4 to pluripotency and cell cycle genes in determining the identity of ESCs. Aurkb phosphorylates Oct4(S229) during G2/M phase, leading to the dissociation of Oct4 from chromatin, whereas PP1 binds Oct4 and dephosphorylates Oct4(S229) during M/G1 transition, which resets Oct4-driven transcription for pluripotency and the cell cycle. Aurkb phosphor-mimetic and PP1 binding-deficient mutations in Oct4 alter the cell cycle, effect the loss of pluripotency in ESCs, and decrease the efficiency of somatic cell reprogramming. Our findings provide evidence that the cell cycle is linked directly to ...
Yeast Cdc7 protein kinase and Dbf4 protein are both required for the initiation of DNA replication at the G1/S phase boundary of the mitotic cell cycle. Cdc7 kinase function is stage-specific in the cell cycle, but total Cdc7 protein levels remained unchanged. Therefore, regulation of Cdc7 function appears to be the result of posttranslational modification. In this study, we have attempted to elucidate the mechanism responsible for achieving this specific execution point of Cdc7. Cdc7 kinase activity was shown to be maximal at the G1/S boundary by using either cultures synchronized with alpha factor or Cdc- mutants or with inhibitors of DNA synthesis or mitosis. Therefore, Cdc7 kinase is regulated by a posttranslational mechanism that ensures maximal Cdc7 activity at the G1/S boundary, which is consistent with Cdc7 function in the cell cycle. This cell cycle-dependent regulation could be the result of association with the Dbf4 protein. In this study, the Dbf4 protein was shown to be required for ...
1. Sherr CJ (1996) Cancer cell cycles. Science 274: 1672-1677. doi: 10.1126/science.274.5293.1672 8939849. 2. Sherr CJ, McCormick F (2002) The RB and p53 pathways in cancer. Cancer Cell 2: 103-112. doi: 10.1016/s1535-6108(02)00102-2 12204530. 3. Ren B, Cam H, Takahashi Y, Volkert T, Terragni J, et al. (2002) E2F integrates cell cycle progression with DNA repair, replication, and G(2)/M checkpoints. Genes Dev 16: 245-256. doi: 10.1101/gad.949802 11799067. 4. Dimova DK, Stevaux O, Frolov MV, Dyson NJ (2003) Cell cycle-dependent and cell cycle-independent control of transcription by the Drosophila E2F/RB pathway. Genes Dev 17: 2308-2320. doi: 10.1101/gad.1116703 12975318. 5. Korenjak M, Taylor-Harding B, Binne UK, Satterlee JS, Stevaux O, et al. (2004) Native E2F/RBF complexes contain Myb-interacting proteins and repress transcription of developmentally controlled E2F target genes. Cell 119: 181-193. doi: 10.1016/j.cell.2004.09.034 15479636. 6. van den Heuvel S, Dyson NJ (2008) Conserved functions ...
E2-2 alteration influences cell cycle exit of progenitors in vivo. (A)E2-2 overexpression increased cell cycle exit (EdU+Ki67-/EdU+) among the progenitor cell
BC: Thats what the cell cycle does!. FC: Cell Cycle. 1: What is the cell cycle? , The cell cycle is a process in which a cell grows and divides to create a copy of itself. Some orangisms reproduce through the cell cycle and in complex multicellular organisms, the cell cycle is used to allow the organism to grow and to reproduce worn out cells.. 2: Interphase , During interphase, a cell increase in mass, replicates its DNA, and prepares prophase.. 4: Prophase , It is when the loose DNA starts to gather to form chromatid, the DNA copies itself, the spindle fibers start to form, and the cell prepares itself for cell division.. 6: Metaphase , The duplicated chromosomes become aligned in the center of the cell, spindle fibers attach themselves to the centromere of the chromosomes.. 8: Anaphase , The stage of mitosis in which the duplicated sets of chromosomes separate and two indentical groups move to opposite poles of the cell.. 10: Telophase , A nuclear membrane re-forms around each new group of ...
BC: Thats what the cell cycle does!. FC: Cell Cycle. 1: What is the cell cycle? , The cell cycle is a process in which a cell grows and divides to create a copy of itself. Some orangisms reproduce through the cell cycle and in complex multicellular organisms, the cell cycle is used to allow the organism to grow and to reproduce worn out cells.. 2: Interphase , During interphase, a cell increase in mass, replicates its DNA, and prepares prophase.. 4: Prophase , It is when the loose DNA starts to gather to form chromatid, the DNA copies itself, the spindle fibers start to form, and the cell prepares itself for cell division.. 6: Metaphase , The duplicated chromosomes become aligned in the center of the cell, spindle fibers attach themselves to the centromere of the chromosomes.. 8: Anaphase , The stage of mitosis in which the duplicated sets of chromosomes separate and two indentical groups move to opposite poles of the cell.. 10: Telophase , A nuclear membrane re-forms around each new group of ...
The observability condition, which describes the cancer cell cycle kinetic state, is developed for determination of the initial cell age vectors. This cond
0.05, C< 0.01 vs. the control group). Analysis ... Cell cycle analysis The cells were cultured in a six-well plate for 24 hours and then incubated with different ratios of CIK (10:1, 20:1, or 30:1) for 72 hours. The cells were then digested, resuspended, incubated with P-gp antibodies for 30?moments at 4C, and washed twice in PBS. As demonstrated in Table?1, CIK cells caused a significant dose-dependent build up of A549 cells in the G2/M phases, lightly in the G0/G1, and a decrease of H phases from 1:10 to 1:30 at 48 hours Rilpivirine (Fig?3.) The variations in cell cycle distribution between the A549 and CIK treated A549 cells Rilpivirine were statistically significant (< 0.01). This indicated that CIK cells affected the distribution of A549 cells in each phase of the cell cycle, especially at higher concentrations (Table?1). Table 1 Effect of CIK cells on cell cycle distribution in A549 cells Number 3 The effect of cell cycle progress in A549 by cytokine-induced monster cells. Cell cycle ...
0.05, C< 0.01 vs. the control group). Analysis ... Cell cycle analysis The cells were cultured in a six-well plate for 24 hours and then incubated with different ratios of CIK (10:1, 20:1, or 30:1) for 72 hours. The cells were then digested, resuspended, incubated with P-gp antibodies for 30?moments at 4C, and washed twice in PBS. As demonstrated in Table?1, CIK cells caused a significant dose-dependent build up of A549 cells in the G2/M phases, lightly in the G0/G1, and a decrease of H phases from 1:10 to 1:30 at 48 hours Rilpivirine (Fig?3.) The variations in cell cycle distribution between the A549 and CIK treated A549 cells Rilpivirine were statistically significant (< 0.01). This indicated that CIK cells affected the distribution of A549 cells in each phase of the cell cycle, especially at higher concentrations (Table?1). Table 1 Effect of CIK cells on cell cycle distribution in A549 cells Number 3 The effect of cell cycle progress in A549 by cytokine-induced monster cells. Cell cycle ...
Takes two to Tango: the tale of ApiAP2 transcription factors and the regulation of crucial cell cycle functions in the apicomplexan parasite Toxoplasma ...
Biomedical engineers report a significant advance in efforts to repair a damaged heart after a heart attack, using grafted heart-muscle cells to create a repair patch. The key was overexpressing a gene that activates the cell-cycle of the grafted muscle cells, so they grow and divide more than control grafted cells. Up to now, an extremely low amount of engraftment of cardiomyocytes has been a stumbling block in hopes to use grafted cells to repair hearts after a heart attack. Without the successful repair that a graft could potentially offer, the damaged heart is prone to later heart failure and patient death. In experiments in a mouse model, researchers showed that gene overexpression of the cell-cycle activator CCND2 increased the proliferation of grafted cardiomyocytes. This led to increased remuscularization of the heart at the dead-tissue site of the heart attack, a larger graft size, improved cardiac function and decreased size of the dead tissue, or infarct. Besides regenerating muscle, ...
University of Iowa News. June 1, 2006. UI Cancer Researchers Receive Grant To Study Cell Cycle Checkpoints University of Iowa Roy J. and Lucille A. Carver College of Medicine researchers in the UI Holden Comprehensive Cancer Center have been awarded a five-year, $1.5 million grant from the National Cancer Institute to investigate a new hypothesis about how the mammalian cell cycle is regulated.. The cell cycle is the normal, orderly growth and division of cells. This process, also known as proliferation, is usually tightly controlled, but in cancers the process goes awry and malignant cells proliferate in an uncontrolled manner. Understanding the genetic and biochemical mechanisms that govern the cell cycle could lead to new and better cancer therapies that kill cancer cells but are not toxic to normal cells. The research team, led by Prabhat Goswami, Ph.D., UI assistant professor of radiation oncology in the Free Radical and Radiation Biology Graduate Program, will test the idea that reactive ...
Circadian oscillation and cell cycle progression are the two most essential rhythmic events present in almost all organisms. Circadian rhythms keep track of time and provide temporal regulation with a period of about 24 h. The cell cycle is optimiz
Click to view full text. Objective: The fermented wheat germ extract, which is the active ingredient of nutraceuticals widely used by cancer patients in Europe, Korea and the United States, possesses cytotoxic and anti-metastatic effects in various human malignancies. In estrogen responsive MCF-7 breast cancer cells, it has been shown to potentiate the induction of apoptosis by tamoxifen. However, its effects in triple-negative and Her2-overexpressing breast cancer cells and interactions with chemotherapy have not been investigated until now.. Methods: Cytotoxicity of Avemar lyophilisate alone and in combination with docetaxel was assessed by MTT and clonogenic assays in MCF-7 estrogen responsive, HCC-38 triple-negative and SKBR-3 Her2/neu overexpressing cells. Cell cycle phase distribution was determined by FACS. Apoptosisassociated activaton of caspase-3/7 was measured by Caspase-Glo Assay. Inhibition of tumor cell invasion was quantified using the ORIS Cell Invasion kit.. Results: Avemar ...
Although cells posterior to the SMW are normally quiescent, cell cycle re-entry occurs after tissue damage (Fan and Bergmann, 2008). Expression of the pro-apoptotic gene hid with the GMR promoter, which is expressed posterior to the MF (supplementary material Fig. S1A), induces extensive cell death (Fig. 1E,F). Dying, caspase-positive cells with pyknotic nuclei are extruded from the basal surface of the eye disc (supplementary material Fig. S1B,C), as in other discs (Gibson and Perrimon, 2005; Shen and Dahmann, 2005). Not all cells posterior to the SMW die, and some overcome cell cycle inhibition and re-enter S phase in a wave of proliferation (Fig. 1D,D′; Fan and Bergmann, 2008). GMR-hid flies are nearly eyeless (Fig. 1C), indicating that increased proliferation cannot fully compensate for tissue loss, probably because GMR-hid expression during pupal stages induces extensive apoptosis after the potential to re-enter the cell cycle is lost. Thus, GMR-hid eye discs behave somewhat differently ...
TY - JOUR. T1 - PARP1 promoter links cell cycle progression with adaptation to oxidative environment. AU - Pietrzak, Julita. AU - Spickett, Corinne M.. AU - Płoszaj, Tomasz. AU - Virág, László. AU - Robaszkiewicz, Agnieszka. PY - 2018/9. Y1 - 2018/9. N2 - Although electrophiles are considered as detrimental to cells, accumulating recent evidence indicates that proliferating non-cancerous and particularly cancerous cells utilize these agents for pro-survival and cell cycle promoting signaling. Hence, the redox shift to mild oxidant release must be balanced by multiple defense mechanisms. Our latest findings demonstrate that cell cycle progression, which dictates oxidant level in stress-free conditions, determines PARP1 transcription. Growth modulating factors regulate CDK4/6-RBs-E2Fs axis. In cells arrested in G1 and G0, RB1-E2F1 and RBL2-E2F4 dimers recruit chromatin remodelers such as HDAC1, SWI/SNF and PRC2 to condense chromatin and turn off transcription. Release of retinoblastoma-based ...