scholarly journals Long-range memory of growth and cycle progression correlates cell cycles in lineage trees

2018 ◽  
Author(s):  
Erika E Kuchen ◽  
Nils Becker ◽  
Nina Claudino ◽  
Thomas Höfer

Mammalian cell proliferation is controlled by mitogens. However, how proliferation is coordinated with cell growth is poorly understood. Here we show that statistical properties of cell lineage trees – the cell-cycle length correlations within and across generations – reveal how cell growth controls proliferation. Analyzing extended lineage trees with latent-variable models, we find that two antagonistic heritable variables account for the observed cycle-length correlations. Using molecular perturbations of mTOR and MYC we identify these variables as cell size and regulatory license to divide, which are coupled through a minimum-size checkpoint. The checkpoint is relevant only for fast cell cycles, explaining why growth control of mammalian cell proliferation has remained elusive. Thus, correlated fluctuations of the cell cycle encode its regulation.

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Erika E Kuchen ◽  
Nils B Becker ◽  
Nina Claudino ◽  
Thomas Höfer

Cell heterogeneity may be caused by stochastic or deterministic effects. The inheritance of regulators through cell division is a key deterministic force, but identifying inheritance effects in a systematic manner has been challenging. Here, we measure and analyze cell cycles in deep lineage trees of human cancer cells and mouse embryonic stem cells and develop a statistical framework to infer underlying rules of inheritance. The observed long-range intra-generational correlations in cell-cycle duration, up to second cousins, seem paradoxical because ancestral correlations decay rapidly. However, this correlation pattern is naturally explained by the inheritance of both cell size and cell-cycle speed over several generations, provided that cell growth and division are coupled through a minimum-size checkpoint. This model correctly predicts the effects of inhibiting cell growth or cycle progression. In sum, we show how fluctuations of cell cycles across lineage trees help in understanding the coordination of cell growth and division.


2000 ◽  
Vol 20 (1) ◽  
pp. 233-241 ◽  
Author(s):  
Zhengming Gu ◽  
Cathy Flemington ◽  
Thomas Chittenden ◽  
Gerard P. Zambetti

ABSTRACT DNA damage and/or hyperproliferative signals activate the wild-type p53 tumor suppressor protein, which induces a G1 cell cycle arrest or apoptosis. Although the mechanism of p53-mediated cell cycle arrest is fairly well defined, the p53-dependent pathway regulating apoptosis is poorly understood. Here we report the functional characterization of murine ei24 (also known asPIG8), a gene directly regulated by p53, whose overexpression negatively controls cell growth and induces apoptotic cell death. Ectopic ei24 expression markedly inhibits cell colony formation, induces the morphological features of apoptosis, and reduces the number of β-galactosidase-marked cells, which is efficiently blocked by coexpression of Bcl-XL. Theei24/PIG8 gene is localized on human chromosome 11q23, a region frequently altered in human cancers. These results suggest that ei24 may play an important role in negative cell growth control by functioning as an apoptotic effector of p53 tumor suppressor activities.


1969 ◽  
Vol 24 (12) ◽  
pp. 1624-1629 ◽  
Author(s):  
Günter Cleffmann

Actinomycin in low concentration (0,2 μg/ml — 0,5 μg/ml) prolongs the average duration of the cell cycle of Tetrahymena considerably, but does not inhibit cell division completely. Some parameters of the growing cell have been tested in cell cycles extended in this way and compared to those of normally growing cells. The RNA synthesis of treated cells is reduced to such an extent that the RNA content per cell decreases during the prolonged cell cycle. Nevertheless cell growth, protein synthesis and DNA replication proceed at almost the same rate as in untreated cells. These findings indicate that the presence of actinomycin does not interfere with RNA fractions necessary for growth but reduce the synthesis of RNA fractions which are essential for cell division. Therefore a longer period is needed for their accumulation.


2020 ◽  
Vol 52 (2) ◽  
pp. 168-179 ◽  
Author(s):  
Huilin Gong ◽  
Shan Gao ◽  
Chenghuan Yu ◽  
Meihe Li ◽  
Ping Liu ◽  
...  

Abstract Y-box binding protein 1 (YB-1) is manifested as its involvement in cell proliferation and differentiation and malignant cell transformation. Overexpression of YB-1 is associated with glioma progression and patient survival. The aim of this study is to investigate the influence of YB-1 knockdown on glioma cell progression and reveal the mechanisms of YB-1 knockdown on glioma cell growth, migration, and apoptosis. It was found that the knockdown of YB-1 decreased the mRNA and protein levels of YB-1 in U251 glioma cells. The knockdown of YB-1 significantly inhibited cell proliferation, colony formation, and migration in vitro and tumor growth in vivo. Proteome and phosphoproteome data revealed that YB-1 is involved in glioma progression through regulating the expression and phosphorylation of major proteins involved in cell cycle, adhesion, and apoptosis. The main regulated proteins included CCNB1, CCNDBP1, CDK2, CDK3, ADGRG1, CDH-2, MMP14, AIFM1, HO-1, and BAX. Furthermore, it was also found that YB-1 knockdown is associated with the hypo-phosphorylation of ErbB, mTOR, HIF-1, cGMP-PKG, and insulin signaling pathways, and proteoglycans in cancer. Our findings indicated that YB-1 plays a key role in glioma progression in multiple ways, including regulating the expression and phosphorylation of major proteins associated with cell cycle, adhesion, and apoptosis.


2005 ◽  
Vol 289 (4) ◽  
pp. C826-C835 ◽  
Author(s):  
Sharon Barone ◽  
Tomohisa Okaya ◽  
Steve Rudich ◽  
Snezana Petrovic ◽  
Kathy Tenrani ◽  
...  

Ischemia-reperfusion injury (IRI) in liver and other organs is manifested as an injury phase followed by recovery and resolution. Control of cell growth and proliferation is essential for recovery from the injury. We examined the expression of three related regulators of cell cycle progression in liver IRI: spermidine/spermine N-acetyltransferase (SSAT), p21 (a cyclin-dependent kinase inhibitor), and stathmin. Mice were subjected to hepatic IRI, and liver tissues were harvested at timed intervals. The expression of SSAT, the rate-limiting enzyme in the polyamine catabolic pathway, had increased fivefold 6 h after IRI and correlated with increased putrescine levels in the liver, consistent with increased SSAT enzymatic activity in IRI. The expression of p21, which is transactivated by p53, was undetectable in sham-operated animals but was heavily induced at 12 and 24 h of reperfusion and declined to undetectable baseline levels at 72 h of reperfusion. The interaction of the polyamine pathway with the p53-p21 pathway was shown in vitro, where activation of SSAT with polyamine analog or the addition of putrescine to cultured hepatocytes induced the expression of p53 and p21 and decreased cell viability. The expression of stathmin, which is under negative transcriptional regulation by p21 and controls cell proliferation and progression through mitosis, remained undetectable at 6, 12, and 24 h of reperfusion and was progressively and heavily induced at 48 and 72 h of reperfusion. Double-immunofluorescence labeling with antibodies against stathmin and PCNA, a marker of cell proliferation, demonstrated colocalization of stathmin and PCNA at 48 and 72 h of reperfusion in hepatocytes, indicating the initiation of cell proliferation. The distinct and sequential upregulation of SSAT, p21, and stathmin, along with biochemical activation of the polyamine catabolic pathway in IRI in vivo and the demonstration of p53-p21 upregulation by SSAT and putrescine in vitro, points to the important role of regulators of cell growth and cell cycle progression in the pathophysiology and/or recovery in liver IRI. The data further suggest that SSAT may play a role in the initiation of injury, whereas p21 and stathmin may be involved in the resolution and recovery after liver IRI.


2000 ◽  
Vol 20 (10) ◽  
pp. 3633-3639 ◽  
Author(s):  
Monique R. Adams ◽  
Rosalie Sears ◽  
Faison Nuckolls ◽  
Gustavo Leone ◽  
Joseph R. Nevins

ABSTRACT E2F transcription activity has been shown to play a critical role in cell growth control, regulating the expression of a variety of genes that encode proteins important for the initiation of DNA replication and cell cycle regulation. We have shown that the E2F3 locus encodes two protein products: the E2F3a product, which is tightly regulated by cell growth, and the E2F3b product, which is constitutively expressed throughout the cell cycle. To further explore the mechanism controlling the expression of the two E2F3 gene products, we analyzed the genomic sequences flanking the 5′ region of E2F3a and E2F3b. We find that a series of E2F binding sites confer negative control on the E2F3a promoter in quiescent cells, similar to the control of the E2F1 and E2F2 promoters. In addition, a group of E-box elements, which are Myc binding sites, confer responsiveness to Myc and are necessary for full activation of the E2F3a promoter in response to growth stimulation. Based on these results and past experiments, it appears that the E2F1, E2F2, and E2F3a genes are similarly regulated by growth stimulation, involving a combination of E2F-dependent negative control and Myc-mediated positive control. In contrast, the constitutive expression of the E2F3b gene more closely reflects the control of expression of the E2F4 and E2F5 genes.


2010 ◽  
Vol 22 (1) ◽  
pp. 374
Author(s):  
S. Waghmare ◽  
B. Mir

Gene targeting in primary somatic cells is inefficient compared with embryonic stem cells. This is because of a slow rate of cell proliferation, fewer cells in S-phase at a given time point under normal culture conditions, and low rate of homologous recombination. Homologous recombination occurs mainly in late S-phase and increase in gene targeting efficiency has been reported in S-phase synchronized cells in bovine and rhesus macaque fetal fibroblasts. In this study we tested several growth factors: platelet-derived growth factor (PDGF), tumor necrosis factor a (TNFα), epidermal growth factor (EGF), fibroblast growth factor (FGF), transforming growth factor β1 (TGFβ1), insulin-like growth factor 1 (ILGF-1) and insulin-like growth factor II (ILGF-II) individually and in various combinations to see the effect on cell proliferation rate. Each experimental set consisted of 3 replicates. TGFβ1-, ILGF1-, ILGFII-, and FGF-treated cells grew very slowly compared with untreated cells. However, a combination of 3 growth factors: PDGF (15 ng mL-1), EGF (50 ng mL-1) and TNFa (100 pg mL-1), herein referred to as the cocktail, accelerated cell proliferation rate and reduced cell cycle length on average from 24.5 ± 0.2 to 20.4 ± 0.5 h with no significant change in number of cells in S-phase. Further, cells grown in the presence of the cocktail showed changes in morphology. The cells became spindle-shaped and occupied less surface area per cell compared with untreated cells. Importantly, cocktail-treated cells maintained a normal karyotype without any chromosomal abnormality. Thymidine has been used successfully to block various cell types in S-phase but it failed to synchronize these cells in S-phase in the concentration range of 2 to 10 mM for 24 to 48 h. However, serum starvation (0.2% fetal bovine serum) for 48 h blocked the cell proliferation rate effectively and synchronized cells in G0 phase (80-82% cells). After releasing from the block, cells were grown in the absence or presence of cocktail and cell cycle analysis was done at different time points by flow cytometry. Each time point was repeated 3 times. We observed the maximum number of cells in S-phase at 22 to 23 h (61.33% ± 7.77 in cocktail-treated cells v. 41.7% ± 3.28 in untreated cells). In summary, the cocktail-treated cells showed changes in cell morphology, higher proliferation rate, reduction in cell cycle length by 16.7%, and maximum percentage of cells in S-phase following serum starvation but maintained normal karyotypes. This high proliferation rate, reduction in cell cycle length, and maximum number of cells in S-phase should be very helpful in increasing the efficiency of gene-targeting in pig fetal fibroblasts.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Frederik Roos ◽  
Katherina Binder ◽  
Jochen Rutz ◽  
Sebastian Maxeiner ◽  
August Bernd ◽  
...  

The natural compound curcumin exerts antitumor properties in vitro, but its clinical application is limited due to low bioavailability. Light exposure in skin and skin cancer cells has been shown to improve curcumin bioavailability; thus, the object of this investigation was to determine whether light exposure might also enhance curcumin efficacy in bladder cancer cell lines. RT112, UMUC3, and TCCSUP cells were preincubated with low curcumin concentrations (0.1-0.4μg/ml) and then exposed to 1.65 J/cm2visible light for 5 min. Cell growth, cell proliferation, apoptosis, cell cycle progression, and cell cycle regulating proteins along with acetylation of histone H3 and H4 were investigated. Though curcumin alone did not alter cell proliferation or apoptosis, tumor cell growth and proliferation were strongly blocked when curcumin was combined with visible light. Curcumin-light caused the bladder cancer cells to become arrested in different cell phases: G0/G1 for RT112, G2/M for TCCSUP, and G2/M- and S-phase for UMUC3. Proteins of the Cdk-cyclin axis were diminished in RT112 after application of 0.1 and 0.4μg/ml curcumin. Cell cycling proteins were upregulated in TCCSUP and UMUC3 in the presence of 0.1μg/ml curcumin-light but were partially downregulated with 0.4μg/ml curcumin. 0.4μg/ml (but not 0.1μg/ml) curcumin-light also evoked late apoptosis in TCCSUP and UMUC3 cells. H3 and H4 acetylation was found in UMUC3 cells treated with 0.4μg/ml curcumin alone or with 0.1μg/ml curcumin-light, pointing to an epigenetic mechanism. Light exposure enhanced the antitumor potential of curcumin on bladder cancer cells but by different molecular action modes in the different cell lines. Further studies are necessary to evaluate whether intravesical curcumin application, combined with visible light, might become an innovative tool in combating bladder cancer.


2021 ◽  
Author(s):  
Jiamin Ding ◽  
Zuoliang Chen ◽  
Wanlu Chen ◽  
Zhongxiong Ma ◽  
Yunde Xie ◽  
...  

Abstract Background: Qilan preparation, a complex Chinese herbal medicine consisting of ingredients extracted from Radix Astragali, Gynostemma Pentaphyllum, Rhizoma Chuanxiong and selenium- rich green tea and known for ‘fortifying the spleen and boosting qi, quickening the blood and transforming stasis, and resolving toxins and relieving pain, is used for the prevention and management of oral diseases. The aim of this study was to examine the antitumor effects of Qilan preparation on oral squamous cell carcinoma (OSCC) in vitro and to explore its underlying mechanisms of action. Methods: Human Tca8113 tongue squamous cell carcinoma (TSCC) cells were tested. Cell proliferation, cell cycle distribution and apoptosis were examined using cell counting kit-8 (CCK8) and flow cytometry (FCM). The expression of PTEN and PDCD4 were determined by western blot. Changes in miR-21 levels were quantified using TaqMan stem-loop real-time PCR. After miR-21 was transiently transfected into Tca8113 cells using Lipofectamine®3000, cell proliferation, apoptosis and miR-21 and PDCD4 expression levels were measured.Results: Qilan preparation inhibited Tca8113 cell growth in a dose- and time-dependent manner by inducing apoptosis and cell cycle arrest in S-phase, decreasing miR-21 levels and increasing PTEN and PDCD4 expression. MiR-21 overexpression reversed the Qilan preparation-induced suppression of cell proliferation and induction of apoptosis while also blocking the increase in PDCD4.Conclusions: Our study revealed, for the first time, the ability of Qilan preparation to suppress TSCC cell growth and elucidated that Qilan preparation elicits its anti-cancer actions via either the miR-21/PDCD4 or PTEN pathway.


2021 ◽  
Vol 118 (4) ◽  
pp. e2016778118
Author(s):  
Zebulon G. Levine ◽  
Sarah C. Potter ◽  
Cassandra M. Joiner ◽  
George Q. Fei ◽  
Behnam Nabet ◽  
...  

O-GlcNAc transferase (OGT), found in the nucleus and cytoplasm of all mammalian cell types, is essential for cell proliferation. Why OGT is required for cell growth is not known. OGT performs two enzymatic reactions in the same active site. In one, it glycosylates thousands of different proteins, and in the other, it proteolytically cleaves another essential protein involved in gene expression. Deconvoluting OGT’s myriad cellular roles has been challenging because genetic deletion is lethal; complementation methods have not been established. Here, we developed approaches to replace endogenous OGT with separation-of-function variants to investigate the importance of OGT’s enzymatic activities for cell viability. Using genetic complementation, we found that OGT’s glycosyltransferase function is required for cell growth but its protease function is dispensable. We next used complementation to construct a cell line with degron-tagged wild-type OGT. When OGT was degraded to very low levels, cells stopped proliferating but remained viable. Adding back catalytically inactive OGT rescued growth. Therefore, OGT has an essential noncatalytic role that is necessary for cell proliferation. By developing a method to quantify how OGT’s catalytic and noncatalytic activities affect protein abundance, we found that OGT’s noncatalytic functions often affect different proteins from its catalytic functions. Proteins involved in oxidative phosphorylation and the actin cytoskeleton were especially impacted by the noncatalytic functions. We conclude that OGT integrates both catalytic and noncatalytic functions to control cell physiology.


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