The relationship between histone H3 phosphorylation and acetylation throughout the mammalian cell cycleThis paper is one of a selection of papers published in this Special Issue, entitled 27th International West Coast Chromatin and Chromosome Conference, and has undergone the Journal's usual peer review process.

2006 ◽  
Vol 84 (4) ◽  
pp. 640-657 ◽  
Author(s):  
Kirk J. McManus ◽  
Michael J. Hendzel
Keyword(s):  
Cell Cycle ◽  
Temporal Dynamics ◽  
Peer Review Process ◽  
Histone H3 ◽  
Specific Cell ◽  
Cell Cycle Time ◽  
Post Translational Modifications ◽  
Amino Terminal ◽  
Spatio Temporal

During interphase, histone amino-terminal tails play important roles in regulating the extent of DNA compaction. Post-translational modifications of the histone tails are intimately associated with regulating chromatin structure: phosphorylation of histone H3 is associated with proper chromosome condensation and dynamics during mitosis, while multiple H2B, H3, and H4 tail acetylations destabilize the chromatin fiber and are sufficient to decondense chromatin fibers in vitro. In this study, we investigate the spatio-temporal dynamics of specific histone H3 phosphorylations and acetylations to better understand the interplay of these post-translational modifications throughout the cell cycle. Using a panel of antibodies that individually, or in combination, recognize phosphorylated serines 10 and 28 and acetylated lysines 9 and 14, we define a series of changes associated with histone H3 that occur as cells progress through the cell cycle. Our results establish that mitosis appears to be a period of the cell cycle when many modifications are highly dynamic. Furthermore, they suggest that the upstream histone acetyltransferases/deacetylases and kinase/phosphatases are temporally regulated to alter their function globally during specific cell cycle time points.

Mitosis-specific phosphorylation of nucleolin by p34cdc2 protein kinase

1990 ◽  
Vol 10 (7) ◽  
pp. 3607-3618
Author(s):  
P Belenguer ◽  
M Caizergues-Ferrer ◽  
J C Labbé ◽  
M Dorée ◽  
F Amalric
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Control ◽  
Nucleolar Organizer ◽  
Serine Phosphorylation ◽  
Nucleolar Organizer Regions ◽  
Rdna Transcription ◽  
Amino Terminal ◽  
Nucleolar Chromatin

Nucleolin is a ubiquitous multifunctional protein involved in preribosome assembly and associated with both nucleolar chromatin in interphase and nucleolar organizer regions on metaphasic chromosomes in mitosis. Extensive nucleolin phosphorylation by a casein kinase (CKII) occurs on serine in growing cells. Here we report that while CKII phosphorylation is achieved in interphase, threonine phosphorylation occurs during mitosis. We provide evidence that this type of in vivo phosphorylation involves a mammalian homolog of the cell cycle control Cdc2 kinase. In vitro M-phase H1 kinase from starfish oocytes phosphorylated threonines in a TPXK motif present nine times in the amino-terminal part of the protein. The same sites which matched the p34cdc2 consensus phosphorylation sequence were used in vivo during mitosis. We propose that successive Cdc2 and CKII phosphorylation could modulate nucleolin function in controlling cell cycle-dependent nucleolar function and organization. Our results, along with previous studies, suggest that while serine phosphorylation is related to nucleolin function in the control of rDNA transcription, threonine phosphorylation is linked to mitotic reorganization of nucleolar chromatin.

scholarly journals Differences in cell cycle characteristics among patients with acute nonlymphocytic leukemia

Blood ◽  
1987 ◽  
Vol 69 (6) ◽  
pp. 1647-1653 ◽  
Author(s):  
A Raza ◽  
Y Maheshwari ◽  
HD Preisler
Keyword(s):  
Cell Cycle ◽  
Tritiated Thymidine ◽  
S Phase ◽  
Total Cell ◽  
Acute Nonlymphocytic Leukemia ◽  
Cell Cycle Time ◽  
Myeloid Leukemias ◽  
History Of

The proliferative characteristics of myeloid leukemias were defined in vivo after intravenous infusions of bromodeoxyuridine (BrdU) in 40 patients. The percentage of S-phase cells obtained from the biopsies (mean, 20%) were significantly higher (P = .00003) than those determined from the bone marrow (BM) aspirates (mean, 9%). The post- BrdU infusion BM aspirates from 40 patients were incubated with tritiated thymidine in vitro. These double-labeled slides were utilized to determine the duration of S-phase (Ts) in myeloblasts and their total cell cycle time (Tc). The Ts varied from four to 49 hours (mean, 19 hours; median, 17 hours). Similarly, there were wide variations in Tc of individual patients ranging from 16 to 292 hours (mean, 93 hours; median, 76 hours). There was no relationship between Tc and the percentage of S-phase cells, but there was a good correlation between Tc and Ts (r = .8). Patients with relapsed acute nonlymphocytic leukemia (ANLL) appeared to have a longer Ts and Tc than those studied at initial diagnosis. A subgroup of patients at either extreme of Tc were identified who demonstrated clinically documented resistance in response to multiple courses of chemotherapy. We conclude that Ts and Tc provide additional biologic information that may be valuable in understanding the variations observed in the natural history of ANLL.

The Cdk and PCNA domains on p21Cip1 both function to inhibit G1/S progression during hyperoxia

2004 ◽  
Vol 286 (3) ◽  
pp. L506-L513 ◽  
Author(s):  
Christopher E. Helt ◽  
Rhonda J. Staversky ◽  
Yi-Jang Lee ◽  
Robert A. Bambara ◽  
Peter C. Keng ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Molecular Mechanisms ◽  
Kinase Inhibitors ◽  
Fluorescent Protein ◽  
Nuclear Antigen ◽  
Cell Cycle Regulators ◽  
Amino Terminal ◽  
Binding Domains ◽  
Green Fluorescent

This study investigates molecular mechanisms underlying cell cycle arrest when cells are exposed to high levels of oxygen (hyperoxia). Hyperoxia has previously been shown to increase expression of the cell cycle regulators p53 and p21. In the current study, we found that p53-deficient human lung adenocarcinoma H1299 cells failed to induce p21 or growth arrest in G1 when exposed to 95% oxygen. Instead, cells arrested in S and G2. Stable expression of p53 restored induction of p21 and G1 arrest without affecting mRNA expression of the other Cip or INK4 G1 kinase inhibitors. To confirm the role of p21 in G1 arrest, we created H1299 cells with tetracycline-inducible expression of enhanced green fluorescent protein (EGFP), EGFP fused to p21 (EGFp21), or EGFP fused to p27 (EGFp27), a related cell cycle inhibitor. The amino terminus of p21 and p27 bind cyclin-dependent kinases (Cdk), whereas the carboxy terminus of p21 binds the sliding clamp proliferating cell nuclear antigen (PCNA). EGFp21 or EGFp27, but not EGFP by itself, restored G1 arrest during hyperoxia. When separately overexpressed, the amino-terminal Cdk and carboxy-terminal PCNA binding domains of p21 each prevented cells from exiting G1 during exposure. These findings demonstrate that exposure in vitro to hyperoxia exerts G1 arrest through p53-dependent induction of p21 that suppresses Cdk and PCNA activity. Because PCNA also participates in DNA repair, these results raise the possibility that p21 also affects repair of oxidized DNA.

scholarly journals Profiling of Epigenetic Features in Clinical Samples Reveals Novel Widespread Changes in Cancer

Cancers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 723 ◽  
Author(s):  
Roberta Noberini ◽  
Camilla Restellini ◽  
Evelyn Oliva Savoia ◽  
Francesco Raimondi ◽  
Lavinia Ghiani ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Expression Profiles ◽  
Histone H3 ◽  
Gene Expression Profiles ◽  
Culture Conditions ◽  
Clinical Samples ◽  
Post Translational Modifications ◽  
A Cell ◽  
Cancer Types ◽  
Histone Modifying Enzymes

Aberrations in histone post-translational modifications (PTMs), as well as in the histone modifying enzymes (HMEs) that catalyze their deposition and removal, have been reported in many tumors and many epigenetic inhibitors are currently under investigation for cancer treatment. Therefore, profiling epigenetic features in cancer could have important implications for the discovery of both biomarkers for patient stratification and novel epigenetic targets. In this study, we employed mass spectrometry-based approaches to comprehensively profile histone H3 PTMs in a panel of normal and tumoral tissues for different cancer types, identifying various changes, some of which appear to be a consequence of the increased proliferation rate of tumors, while others are cell-cycle independent. Histone PTM changes found in tumors partially correlate with alterations of the gene expression profiles of HMEs obtained from publicly available data and are generally lost in culture conditions. Through this analysis, we identified tumor- and subtype-specific histone PTM changes, but also widespread changes in the levels of histone H3 K9me3 and K14ac marks. In particular, H3K14ac showed a cell-cycle independent decrease in all the seven tumor/tumor subtype models tested and could represent a novel epigenetic hallmark of cancer.

Sequence specificity of docetaxel (Doc) and the proteasome inhibitor PS-341 combinations in androgen-independent (AI) prostate cancer (CaP)

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 13150-13150
Author(s):  
W. S. Holland ◽  
P. N. Lara ◽  
T. Kimura ◽  
T. Kenosi ◽  
D. R. Gandara ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Patient Outcomes ◽  
Tumor Volume ◽  
Specific Cell ◽  
Sequence Specificity ◽  
Cycle Arrest ◽  
Best Response ◽  
Altered Cell

13150 Background: AI CaP is an invariably fatal disease. While treatment with Doc, a microtubule-stabilizing taxane, improves survival, patient outcomes remain suboptimal. PS-341 inhibits degradation of cell cycle and tumor suppressor proteins resulting in cycle arrest and apoptosis. We hypothesized that the combination of Doc with PS-341 would abrogate the abnormal survival response seen in AI CaP and lead to improved tumor cell kill, but that results would be dependent on administration schedule due to interactive cell cycle kinetics. Methods: The PC3 cell line model of AI CaP was evaluated in vitro and in vivo to determine response to Doc or PS-341 alone, and in combination in sequences of PS-341→Doc, Doc→PS-341, and simultaneous (PS-341 + Doc). Cell cycle and protein analyses were performed by flow cytometry and Western blotting, respectively. For nu/nu mouse xenografts, 5 × 106 cells were injected subcutaneously into each flank. The agents were administered either together or 24hr apart, with all regimens given weekly [IP doses: Doc: 10 mg/kg; PS-341: 0.5 mg/kg]. Results: in vitro: Each combination showed an increased apoptotic sub-G1 population versus untreated cells, in addition to altered cell cycling in a sequence-specific manner. Of the combinations, PS-341 + Doc showed the largest sub-G1 while Doc→PS-341 had the lowest sub-G1 but the largest S-phase content; in vivo: PS-341 + Doc showed a cytotoxic effect (reduction in tumor volume) while the combinations of Doc→PS-341 and PS-341→Doc both showed growth inhibition (stabilization of tumor growth) as best response. Conclusions: Combinations of PS-341 and Doc have sequence specific cell cycle effects leading to increases in apoptosis (PS-341 + Doc) or cell cycle arrest (Doc→PS-341). Clinical validation of these findings is warranted. (ACS: CRTG-0019701-CCE) No significant financial relationships to disclose.

Stem cell studies of human malignant brain tumors

1985 ◽  
Vol 63 (3) ◽  
pp. 426-432 ◽  
Author(s):  
Bertrand Pertuiset ◽  
Dolores Dougherty ◽  
Carlos Cromeyer ◽  
Takao Hoshino ◽  
Mitchel Berger ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Brain Tumors ◽  
Tritiated Thymidine ◽  
Early Passage ◽  
Cell Cycle Time ◽  
Content Type ◽  
Cell Kill ◽  
Fine Print

✓ The proliferation kinetics were studied in early-passage cultures of cells from 13 human malignant brain tumors and two specimens of normal brain under conditions similar to those used in clonogenic cell-survival studies. Autoradiography was performed in all but four cases to estimate the fraction of cells actively replicating deoxyribonucleic acid (DNA), the approximate cell cycle time, and the effect of low-dose tritiated thymidine on cell proliferation. The mean tumor cell doubling time (TD) was 53 hours for five glioblastomas, 46 hours for two ependymomas, and 83 hours for two medulloblastomas. A gliosarcoma grew fastest (TD = 22 hours) in culture and a pilocytic astrocytoma grew slowest (TD = 144 hours). The approximate cell cycle time ranged from 1 to 2.5 days for all tumors tested. This suggests that chemotherapeutic agents that predominantly kill proliferating cells should be administered in vitro for at least 2 to 2.5 days to achieve maximum cell kill. The approximate growth fraction ranged from 0.65 to 0.96 for all tumors except for the two medulloblastomas and the pilocytic astrocytoma, which had growth fractions of 0.34 and 0.35, respectively. Most laboratories investigating the chemosensitivity of primary or early-passage human tumor cells require that 40% to 70% of cells be killed to consider a drug active in vitro. The results of this study suggest that the cell-cycle-specific agents cannot achieve a high enough cell kill to be considered active for some tumors that grow slowly in culture. An estimate of the in vitro growth rate is necessary to reliably interpret cell-survival results with such agents. Tritiated thymidine appeared to slow cell proliferation in some of the cultures, presumably as a result of radiation-induced DNA damage caused by tritium that had been incorporated into DNA. The degree to which cell growth was slowed in individual tumors correlated with the patient's clinical response to radiation therapy and postoperative survival time.

scholarly journals Onset of erythropoietin response in murine erythroid colony-forming units: assignment to early S-phase in a specific cell generation

Blood ◽  
1992 ◽  
Vol 79 (10) ◽  
pp. 2749-2758 ◽  
Author(s):  
KT Landschulz ◽  
SH Boyer ◽  
AN Noyes ◽  
OC Rogers ◽  
LP Frelin
Keyword(s):  
Cell Cycle ◽  
In Vitro Maturation ◽  
S Phase ◽  
Heme Biosynthesis ◽  
Specific Cell ◽  
Differential Centrifugation ◽  
Serum Factors ◽  
Colony Forming Units ◽  
Pulsed Exposures

Murine erythroid colony-forming units (CFU-E) representing successive cell generations in a six-generation long in vitro maturation sequence were tested for their response to erythropoietin (Epo) by measurement of Epo-exposure times necessary to stimulate heme biosynthesis. Generation I CFU-E, which produce mainly 32-cell erythroid colonies, were isolated in 82% average purity from spleens of thiamphenicol- treated anemic animals via differential centrifugation. Generation II CFU-E, which produce mainly 16-cell colonies, were similarly isolated in 51% average purity. Although both types of CFU-E had equivalent dose sensitivity to and affinity for Epo, generation II CFU-E responded to shorter pulses of Epo than did generation I. Correlations between DNA cell-cycle profiles and 59Fe-heme biosynthesis resulting from pulsed exposures established that appreciable Epo response only begins when CFU-E attain early S-phase of generation II. Because CFU-E did not require Epo or other serum factors to pass from generation I to II and because the onset of Epo responsiveness coincided with the beginning of DNA replication in generation II, we suppose that differentiation has reprogrammed one or more of the events associated with generation II S- phase in CFU-E and that these alterations allow Epo to act. Further comparisons between CFU-E from generation I and II may allow us to identify the alterations in question and the nature of their interaction with Epo.

scholarly journals Excess histone H3 is a Chk1 inhibitor that controls embryonic cell cycle progression

2020 ◽  
Author(s):  
Yuki Shindo ◽  
Amanda A. Amodeo
Keyword(s):  
Cell Cycle ◽  
Cell Fate ◽  
Cell Cycle Progression ◽  
Histone H3 ◽  
Embryonic Cell ◽  
Cycle Progression ◽  
Cell Cycles ◽  
Embryonic Cell Cycle

AbstractThe early embryos of many species undergo a switch from rapid, reductive cleavage divisions to slower, cell fate-specific division patterns at the Mid-Blastula Transition (MBT). The maternally loaded histone pool is used to measure the increasing ratio of nuclei to cytoplasm (N/C ratio) to control MBT onset, but the molecular mechanism of how histones regulate the cell cycle has remained elusive. Here, we show that excess histone H3 inhibits the DNA damage checkpoint kinase Chk1 to promote cell cycle progression in the Drosophila embryo. We find that excess H3-tail that cannot be incorporated into chromatin is sufficient to shorten the embryonic cell cycle and reduce the activity of Chk1 in vitro and in vivo. Removal of the Chk1 phosphosite in H3 abolishes its ability to regulate the cell cycle. Mathematical modeling quantitatively supports a mechanism where changes in H3 nuclear concentrations over the final cell cycles leading up to the MBT regulate Chk1-dependent cell cycle slowing. We provide a novel mechanism for Chk1 regulation by H3, which is crucial for proper cell cycle remodeling during early embryogenesis.

scholarly journals FUCCI-based live imaging platform reveals cell cycle dynamics and identifies pro-proliferative compounds in human iPSC-derived cardiomyocytes

2021 ◽  
Author(s):  
Francesca Murganti ◽  
Wouter Derks ◽  
Marion Baniol ◽  
Irina Simonova ◽  
Katrin Neumann ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Induced Pluripotent Stem Cell ◽  
Cardiac Regeneration ◽  
Indicator System ◽  
Specific Cell ◽  
Cardiomyocyte Proliferation ◽  
Compound Screening ◽  
Cell Cycle Dynamics

One of the major goals in cardiac regeneration research is to replace lost ventricular tissue with new cardiomyocytes. However, cardiomyocyte proliferation drops to low levels in neonatal hearts and is no longer efficient in compensating for the loss of functional myocardium in heart disease. We generated a human induced pluripotent stem cell (iPSC)-derived cardiomyocyte-specific cell cycle indicator system (TNNT2-FUCCI) to characterize regular and aberrant cardiomyocyte cycle dynamics. We visualized cell cycle progression in TNNT2-FUCCI and found G2 cycle arrest in endoreplicating cardiomyocytes. Moreover, we devised a live-cell compound screening platform to identify pro-proliferative drug candidates. We found that the alpha-adrenergic receptor agonist clonidine induced cardiomyocyte proliferation in vitro and increased cardiomyocyte cell cycle entry in neonatal mice. In conclusion, the TNNT2-FUCCI system is a valuable tool to characterize cardiomyocyte cell cycle dynamics and identify pro-proliferative candidates with regenerative potential in the mammalian heart.

scholarly journals Cell Cycle Control by Natural Phenols in Cisplatin-Resistant Cell Lines

2014 ◽  
Vol 9 (10) ◽  
pp. 1934578X1400901 ◽  
Author(s):  
Daniela Catanzaro ◽  
Caterina Vianello ◽  
Eugenio Ragazzi ◽  
Laura Caparrotta ◽  
Monica Montopoli
Keyword(s):  
Cell Cycle ◽  
Squamous Carcinoma ◽  
Cross Resistance ◽  
Specific Cell ◽  
Wild Type ◽  
Cinnamic Acids ◽  
Squamous Carcinoma Cells ◽  
Natural Phenols ◽  
Resistant Cells

Fifteen plant polyphenols, including flavonoids, cinnamic acids, coumarins and capsaicin, were investigated for their capacity to suppress cell growth and regulate the cell cycle of in vitro human ovarian carcinoma (2008 cell line) and cervix squamous carcinoma cells (A431), and their cisplatin (CDDP)-resistant subclones (C13 and A431Pt, respectively). Evaluation of the cytotoxic effects of the polyphenols (0.01–100 μM) indicated that especially rhein and quercetin were almost equiactive in wild type and CDDP-resistant cells, indicating lack of cross-resistance with cisplatin. Capsaicin was more potent in CDDP-resistant subclones than in wild type cells. The order of their potencies is flavonoids > anthraquinones > vanilloids > coumarins > phenols, cinnamic acids. The natural phenols which were most cytotoxic (rhein, quercetin and capsaicin) were able to cause the arrest of the cancer cell cycle, suggesting that specific cell cycle regulatory proteins are possibly involved in their intracellular mechanism of action. In particular, the natural compounds were revealed to be more active in CDDP-resistant cells than in wild types, especially inducing apoptotic death.

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