Nuclear phosphatidylinositols decrease during S-phase of the cell cycle in HeLa cells.

Lamina-associated polypeptide 2 (LAP2) is an integral membrane protein of the inner nuclear membrane that binds to both lamin B and chromatin and has a putative role in nuclear envelope (NE) organization. We found that microinjection of a recombinant polypeptide comprising the nucleoplasmic domain of rat LAP2 (residues 1–398) into metaphase HeLa cells does not affect the reassembly of transport-competent nuclei containing NEs and lamina, but strongly inhibits nuclear volume increase. This effect appears to be specifically due to lamin binding, because it also is caused by microinjection of the minimal lamin-binding region of LAP2 (residues 298–373) but not by the chromatin-binding domain (residues 1–88). Injection of the lamin-binding region of rat LAP2 into early G1 phase HeLa cells also strongly affects nuclear growth; it almost completely prevents the threefold nuclear volume increase that normally occurs during the ensuing 10 h. Moreover, injection of the fragment during early G1 phase strongly inhibits entry of cells into S phase, whereas injection during S phase has no apparent effect on ongoing DNA replication. Since the lamin-binding fragment of LAP2 most likely acts by inhibiting dynamics of the nuclear lamina, our results suggest that a normal function of LAP2 involves regulation of nuclear lamina growth. These data also suggest that lamina dynamics are required for growth of the NE and for nuclear volume increase during the cell cycle, and that progression into S phase is dependent on the acquisition of a certain nuclear volume.

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Fluctuation in radioresponse of HeLa cells during the cell cycle evaluated based on micronucleus frequency

Scientific Reports ◽

10.1038/s41598-020-77969-0 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Hiroaki Shimono ◽

Atsushi Kaida ◽

Hisao Homma ◽

Hitomi Nojima ◽

Yusuke Onozato ◽

...

Keyword(s):

Cell Cycle ◽

Hela Cells ◽

Time Lapse ◽

S Phase ◽

G1 Phase ◽

M Phase ◽

G2 Phase ◽

The Difference ◽

Time Lapse Imaging ◽

First Time

AbstractIn this study, we examined the fluctuation in radioresponse of HeLa cells during the cell cycle. For this purpose, we used HeLa cells expressing two types of fluorescent ubiquitination-based cell cycle indicators (Fucci), HeLa-Fucci (CA)2 and HeLa-Fucci (SA), and combined this approach with the micronucleus (MN) assay to assess radioresponse. The Fucci system distinguishes cell cycle phases based on the colour of fluorescence and cell morphology under live conditions. Time-lapse imaging allowed us to further identify sub-positions within the G1 and S phases at the time of irradiation by two independent means, and to quantitate the number of MNs by following each cell through M phase until the next G1 phase. Notably, we found that radioresponse was low in late G1 phase, but rapidly increased in early S phase. It then decreased until late S phase and increased in G2 phase. For the first time, we demonstrated the unique fluctuation of radioresponse by the MN assay during the cell cycle in HeLa cells. We discuss the difference between previous clonogenic experiments using M phase-synchronised cell populations and ours, as well as the clinical implications of the present findings.

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Molecular cloning of G1 phase mRNAs from a subtractive G1 phase cDNA library

Biochemistry and Cell Biology ◽

10.1139/o93-055 ◽

1993 ◽

Vol 71 (7-8) ◽

pp. 372-380 ◽

Cited By ~ 10

Author(s):

Gin Wu ◽

Shiawhwa Su ◽

Tzyy-Yun Tzeng Kung ◽

R. Curtis Bird

Keyword(s):

Cell Cycle ◽

Cdna Library ◽

Light Chain ◽

Hela Cells ◽

Subtractive Hybridization ◽

S Phase ◽

G1 Phase ◽

Chain Gene ◽

Centrifugal Elutriation ◽

Light Chain Gene

Many G1-phase-specific mRNAs have been identified from various normal or transformed cells based on serum induction and re-entry into the cell cycle from quiescence. However, these mRNAs may not represent some important genes expressed during G1 phase in continuously cycling cells. The eukaryotic cell cycle possesses two cdk (cyclin-dependent kinase) dependent regulatory gates through which cells pass during late G1 phase and G2 phase of each cycle. Subtractive hybridization was employed to synthesize a high R0t fraction cDNA library enriched in sequences expressed during G1 phase prior to passage through the G1-phase gate. To prepare G1-phase cells from continuously cycling cell populations, G1-phase HeLa cells were collected by centrifugal elutriation and highly synchronous S phase cells were obtained by double thymidine block followed by centrifugal elutriation. A G1-phase subtractive cDNA library was prepared by subtracting G1-phase cDNA with a 10-fold excess of S-phase mRNA. Single-stranded, G1-phase cDNAs were isolated by oligo(dA) chromatography. The library was screened with a high R0t fraction subtractive probe population. Following two rounds of screening, 20 positive clones were obtained. Northern blot analysis indicated that six of these clones were enhanced in expression level during G1 phase when compared with S phase. Nucleotide sequence comparison of each clone with the GenBank data base revealed that hG1.11 was highly homologous (99%) to the apoferritin light chain gene and clones hG1.6, hG1.10, hG1.17, and hG1.18 represented new G1-phase-enriched members of four human ribosomal protein gene families (71–95% homology). The last clone, hG1.1, encoded a highly charged polypeptide not previously identified. Additional study of these G1-phase-enriched mRNAs will be required to determine their role in cell cycle progression and the G1-phase gateway through which cells transit as they proceed through the cell cycle.Key words: cell cycle, G1 phase, subtractive hybridization, cDNA cloning, ribosomal proteins, apoferritin light chain, HeLa cells.

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Bioinformatics Analysis of Gefitinib or Rapamycin on Inhibiting the Survival of Hela in the Low Glucose and High Lactic Acid Environment

Journal of Medical Imaging and Health Informatics ◽

10.1166/jmihi.2019.2636 ◽

2019 ◽

Vol 9 (2) ◽

pp. 319-323 ◽

Cited By ~ 1

Author(s):

Li Ping ◽

Li Mingzhu ◽

Lü Yuchun

Keyword(s):

Cell Cycle ◽

Lactic Acid ◽

Hela Cells ◽

Annexin V ◽

S Phase ◽

Normal Glucose ◽

Acid Environment ◽

G0 Phase ◽

High Lactate ◽

Glucose Group

Objective: To explore on the antitumor effect of gefitinib and rapamycin and possible mechanism in normal glucose and high lactic acid microenvironment. Methods: Hela cells are cultured in six conditions: the normal glucose group (NG, glucose 3 mmol/L); the normal glucose + gefitinib group (NGG, glucose 3 mmol/L, gefitinib 2.67 μmol/L); the normal glucose + rapamycin group (NGR, glucose 3 mmol/L, rapamycin 2.67 μmol/L); the high lactate group (NGHL, glucose 3 mmol/L, lactic acid 2.5 mmol/L); the normal glucose + high lactate + gefitinib group (NGHLG, glucose 3 mmol/L, lactic acid 2.5 mmol/L, gefitinib 2.67μmol/L); the normal glucose + high lactate + rapamycin group (NGHLG, glucose 10 mmol/L, lactic acid 2.5 mmol/L, rapamycin 2.67μmol/L). Growth inhibitory rate of Hela cell is determined by CCK-8; Flow cytometry (FCM) is performed to evaluate the cell cycle; The annexin V-phycoerythrin/Propidium Iodide (annexin V-PE/PI) staining combined with flow cytometry is used to examine the cell cycle and apoptosis of Hela cells. Results: Under normal glucose with gefitinib or rapamycin environment, the apoptosis rate of Hela cells is higher than that of the normal glucose group. But the cell apoptosis rate of the gefitinib or rapamycin group decreases in high lactic acid and normal glucose, which is lower than that of the normal glucose and high lactate. Combined with the results of cell cycle, compared with the normal glucose group, percentage of Hela cells in G1/G0 phase increases significantly, the proportion of S phase cells decreases significantly in high lactic acid environment. In the normal glucose and gefitinib environment, Hela cells in G1/G0 phase and S phase are slightly higher than the proportion of normal glucose group, and G2/M phase cells are mild lower than the proportion of normal glucose group. Under the environment of high lactate and normal glucose, the percentage of G1/G0 and S phase cells in the gefitinib increase. As for rapamycin, normal glucose and high lactic acid environment makes cells stay in G1/G0 phase. The presence of rapamycin in the environment of normal sugar and high lactate makes more cells stay in G1/G0 or G2/M phase. Conclusion: Normal glucose and high lactic acid environment is conducive to Hela cell survival, and can promote the expression of EGFR and mTOR. Gefitinib is an antagonist of EGFR and rapamycin is an inhibitor of mTOR.

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TIME SEQUENCE OF NUCLEAR PORE FORMATION IN PHYTOHEMAGGLUTININ-STIMULATED LYMPHOCYTES AND IN HELA CELLS DURING THE CELL CYCLE

The Journal of Cell Biology ◽

10.1083/jcb.55.2.433 ◽

1972 ◽

Vol 55 (2) ◽

pp. 433-447 ◽

Cited By ~ 157

Author(s):

Gerd G. Maul ◽

Helmut M. Maul ◽

Joseph E. Scogna ◽

Michael W. Lieberman ◽

Gary S. Stein ◽

...

Keyword(s):

Cell Cycle ◽

Protein Synthesis ◽

Hela Cells ◽

Pore Formation ◽

Human Lymphocytes ◽

Time Sequence ◽

S Phase ◽

Nuclear Pore ◽

Nuclear Surface ◽

Nuclear Pores

The time sequence of nuclear pore frequency changes was determined for phytohemagglutinin (PHA)-stimulated human lymphocytes and for HeLa S-3 cells during the cell cycle. The number of nuclear pores/nucleus was calculated from the experimentally determined values of nuclear pores/µ2 and the nuclear surface. In the lymphocyte system the number of pores/nucleus approximately doubles during the 48 hr after PHA stimulation. The increase in pore frequency is biphasic and the first increase seems to be related to an increase in the rate of protein synthesis. The second increase in pores/nucleus appears to be correlated with the onset of DNA synthesis. In the HeLa cell system, we could also observe a biphasic change in pore formation. Nuclear pores are formed at the highest rate during the first hour after mitosis. A second increase in the rate of pore formation corresponds in time with an increase in the rate of nuclear acidic protein synthesis shortly before S phase. The total number of nuclear pores in HeLa cells doubles from ∼2000 in G1 to ∼4000 at the end of the cell cycle. The doubling of the nuclear volume and the number of nuclear pores might be correlated to the doubling of DNA content. Another correspondence with the nuclear pore number in S phase is found in the number of simultaneously replicating replication sites. This number may be fortuitous but leads to the rather speculative possibility that the nuclear pore might be the site of initiation and/or replication of DNA as well as the site of nucleocytoplasmic exchange. That is, the nuclear pore complex may have multiple functions.

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Apoptosis and S Phase of the Cell Cycle in BeWo Trophoblastic and HeLa Cells are Differentially Modulated by Toxoplasma gondii Strain Types

Placenta ◽

10.1016/j.placenta.2009.07.002 ◽

2009 ◽

Vol 30 (9) ◽

pp. 785-791 ◽

Cited By ~ 19

Author(s):

M.B. Angeloni ◽

N.M. Silva ◽

A.S. Castro ◽

A.O. Gomes ◽

D.A.O. Silva ◽

...

Keyword(s):

Cell Cycle ◽

Toxoplasma Gondii ◽

Hela Cells ◽

S Phase

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Antimycin A as a mitochondria damage agent induces an S phase arrest of the cell cycle in HeLa cells

Life Sciences ◽

10.1016/j.lfs.2008.06.023 ◽

2008 ◽

Vol 83 (9-10) ◽

pp. 346-355 ◽

Cited By ~ 26

Author(s):

Yong Hwan Han ◽

Suhn Hee Kim ◽

Sung Zoo Kim ◽

Woo Hyun Park

Keyword(s):

Cell Cycle ◽

Hela Cells ◽

S Phase ◽

Antimycin A ◽

Phase Arrest ◽

S Phase Arrest

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Adenosine 3':5'-monophosphate content and actions in the division cycle of synchronized HeLa cells.

The Journal of Cell Biology ◽

10.1083/jcb.71.2.515 ◽

1976 ◽

Vol 71 (2) ◽

pp. 515-534 ◽

Cited By ~ 45

Author(s):

C E Zeilig ◽

R A Johnson ◽

E W Sutherland ◽

D L Friedman

Keyword(s):

Cell Cycle ◽

Cyclic Amp ◽

Hela Cells ◽

S Phase ◽

Intracellular Camp ◽

Specific Effects ◽

Low Concentrations ◽

High Concentrations ◽

Camp Levels ◽

Stimulation Of

The involvement of adenosine 3':5'-monophosphate (cAMP) in the regulation of the cell cycle was studied by determining intracellular fluctuations in cAMP levels in synchronized HeLa cells and by testing the effects of experimentally altered levels on cell cycle traverse. Cyclic AMP levels were lowest during mitosis and were highest during late G-1 or early S phase. These findings were supported by results obtained when cells were accumulated at these points with Colcemid or high levels of thymidine. Additional fluctuations in cAMP levels were observed during S phase. Two specific effects of cAMP on cell cycle traverse were found. Elevation of cAMP levels in S phase or G-2 caused arrest of cells in G-2 for as long as 10 h and lengthened M. However, once cells reached metaphase, elevation of cAMP accelerated the completion of mitosis. Stimulation of mitosis was also observed after addition of CaCl2. The specificity of the effects of cAMP was verified by demonstrating that: (a) intracellular cAMP was increased after exposure to methylisobutylxanthine (MIX) before any observed effects on cycle traverse; (b) submaximal concentrations of MIX potentiated the effects of isoproterenol; and (c) effects of MIX and isoproterenol were mimicked by 8-Br-cAMP. MIX at high concentrations inhibited G-1 traverse, but this effect did not appear to be mediated by cAMP. Isoproterenol slightly stimulated G-1 traverse and partially prevented the MIX-induced delay. Moreover, low concentrations of 8-Br-cAMP (0.10-100 muM) stimulated G-1 traverse, whereas high concentrations (1 mM) inhibited. Both of these effects were also observed with the control, Br-5'-AMP, at 10-fold lower concentrations.

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Induction of S-phase Cell Cycle Arrest and Apoptosis in HeLa Cells by Small RNAs Fraction ofSolanum tuberosumL.

MicroRNA ◽

10.2174/2211536608666181218114254 ◽

2019 ◽

Vol 8 (3) ◽

pp. 180-188

Author(s):

Sunny Yadav ◽

Devashree Jahagirdar ◽

Mamta Shekhawat ◽

Nilesh Kumar Sharma

Keyword(s):

Cell Cycle ◽

Cell Cycle Arrest ◽

Cancer Cells ◽

Hela Cells ◽

Small Rnas ◽

Cancer Therapeutics ◽

S Phase ◽

Phase Cell ◽

Cycle Arrest ◽

Appreciable Increase

Background:In cancer therapeutics, several new classes of small molecules based targeted drug options are reported including peptide mimetic and small RNAs therapeutics.Objective:Small RNAs represent a class of short non-coding endogenous RNAs that play an important role in transcriptional and post transcriptional gene regulation among varied types of species including plants and animals.Methods:To address the role of small RNAs from plant sources upon cancer cells, authors report on the effects of small RNAs fraction of potato in in-vitro model of human derived HeLa cancer cells. This paper reports the anti-proliferative and anti-survival effect of small RNAs fraction of S. tuberosum L. (potato) tuber tissue. Here, authors employed small RNAs fractionation protocol, cell viability, cell cytotoxicity MTT, PI stained cell cycle analysis and FITC-Annexin-V/PI stained apoptosis assays.Results:In this paper, small RNAs fractions of potato clearly indicate 40-50% inhibition of HeLa cell proliferation and viability. Interestingly, flow cytometer data point out appreciable increase from 7% to 14% of S-phase in HeLa cells by displaying the presence of an S-phase cell cycle arrest. Further, arrest in S-phase of HeLa cells is also supported by an appreciable increase in total <2N plus >4N DNA containing HeLa cells over 2N containing HeLa cells. For apoptotic assay, data suggest a significant increase in apoptotic HeLa cells from (5%) control treated HeLa cells to (18%) small RNAs treated HeLa cells.Conclusion:Taken together, findings suggest that small RNAs fractions of potato can induce Sphase cell cycle arrest and these agents can act as an anti-proliferative agent in HeLa cells. This paper proposes a huge scope for novel finding to dissect out the small RNAs target within HeLa cells and other cancer cell types.

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The induction of DNA synthesis in the chick red cell nucleus in heterokaryons during the first cell cycle after fusion with HeLa cells

Journal of Cell Science ◽

10.1242/jcs.18.3.455 ◽

1975 ◽

Vol 18 (3) ◽

pp. 455-490

Author(s):

R.T. Johnson ◽

A.M. Mullinger

Keyword(s):

Cell Cycle ◽

Dna Synthesis ◽

Hela Cells ◽

S Phase ◽

Red Cells ◽

Red Cell ◽

Embryonic Chick ◽

Cell Cycles ◽

Phase Protein ◽

Different Parts

Induction of DNA synthesis in embryonic chick red cells has been examined during the first and second cell cycles after fusion with HeLa cells synchronized in different parts of G1 and S-phase. The data indicate that: (i) the younger the embryonic blood the more rapidly the red cells are induced into DNA synthesis; (ii) the greater the ratio of HeLa to chick nuclei in the heterokaryon, the more rapidly the induction occurs; (iii) DNA synthesis in the chick nucleus can continue after the HeLa nucleus has left S-phase and entered either G2 or mitosis; (iv) the induction potential of late S-phase HeLa is somewhat lower than that of early or mid S-phase cells; (v) less than 10% of the chick DNA is replicated during the first cycle after fusion and only a small proportion (15%) of the chick nuclei approach the 4C value of DNA during the second cycle after fusion; (vi) the newly synthesized DNA is associated either with the condensed regions of the nucleus or with the boundaries between condensed and non-condensed regions; (vii) the chick chromosomes at the first and second mitosis after fusion are in the form of PCC prematurely condensed chromosomes); they are never fully replicated and are often fragmentary; (viii) DNA synthesis in the chick nuclei is accompanied by an influx of protein (both G1 and S-phase protein) from the HeLa component of the heterokaryon.

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