scholarly journals Hypoxia Strongly Affects Mitochondrial Ribosomal Proteins and Translocases, as Shown by Quantitative Proteomics of HeLa Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Paula A. Bousquet ◽  
Joe Alexander Sandvik ◽  
Magnus Ø. Arntzen ◽  
Nina F. Jeppesen Edin ◽  
Stine Christoffersen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Hela Cells ◽  
Quantitative Proteomics ◽  
Ribosomal Proteins ◽  
Poor Prognosis ◽  
Isotope Labeling ◽  
Proteome Analysis ◽  
S Phase ◽  
Hypoxic Environment

Hypoxia is an important and common characteristic of many human tumors. It is a challenge clinically due to the correlation with poor prognosis and resistance to radiation and chemotherapy. Understanding the biochemical response to hypoxia would facilitate the development of novel therapeutics for cancer treatment. Here, we investigate alterations in gene expression in response to hypoxia by quantitative proteome analysis using stable isotope labeling with amino acids in cell culture (SILAC) in conjunction with LCMS/MS. Human HeLa cells were kept either in a hypoxic environment or under normoxic conditions. 125 proteins were found to be regulated, with maximum alteration of 18-fold. In particular, three clusters of differentially regulated proteins were identified, showing significant upregulation of glycolysis and downregulation of mitochondrial ribosomal proteins and translocases. This interaction is likely orchestrated by HIF-1. We also investigated the effect of hypoxia on the cell cycle, which shows accumulation in G1 and a prolonged S phase under these conditions. Implications. This work not only improves our understanding of the response to hypoxia, but also reveals proteins important for malignant progression, which may be targeted in future therapies.

ATF is important to late S phase-dependent regulation of DNA topoisomerase IIα gene expression in HeLa cells

2002 ◽  
Vol 184 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Mee-Young Son ◽  
Tae-Jeong Kim ◽  
Kwang-In Kweon ◽  
Jong-Il Park ◽  
Chung Park ◽  
...  
Keyword(s):  
Gene Expression ◽  
Hela Cells ◽  
S Phase ◽  
Topoisomerase Iiα ◽  
Dna Topoisomerase ◽  
Dna Topoisomerase Iiα

scholarly journals BRCa1 participates in XIST RNa localization on inactive x chromosome

2019 ◽  
Vol 18 (2) ◽  
pp. 21-26
Author(s):  
E. A. Shestakova ◽  
T. A. Bogush
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Confocal Microscopy ◽  
X Chromosome ◽  
Fluorescent Microscopy ◽  
S Phase ◽  
Immunofluorescent Staining ◽  
Heterochromatin Protein ◽  
Inactive X Chromosome ◽  
Xist Rna

Introduction . Inactive X chromosome (Xi) is associated with noncoding XIST RNA, series of proteins and contains multiple epigenetic modifications that altogether determine a silence of the most of X-linked genes. Recently the data were obtained that tumor suppressor BRCA1 is also associated with Xi. The purpose of this study was to reveal the colocalization of BRCA1 and XIST RNA and precise spatial organization on Xi with the high resolution of confocal microscopy.Materials and methods . The object of the study is IMR90hTERT diploid immortalized fibroblast cell line. For BRCA1 and XIST RNA colocalization analysis on Xi the method of fluorescent hybridization in situ associated with immunofluorescent cell staining (immunoFISH) and confocal microscopy were used. For BRCA1 and heterochromatin protein-1 colocalization study the method of double immunofluorescent staining and common fluorescent microscopy were applied. Results . The study using confocal fluorescent microscopy with higher resolution has demonstrated at first the colocalization of BRCA1 with XIST RNA region of Xi revealed with XIST RNA probes and with replicating Xi and autosomes revealed with BrdU in late S-phase of cell cycle. Altogether, the data obtained suggest the involvement of BRCA1 in the inhibition of gene expression on Xi due to the regulation of XIST RNA association with Xi. Moreover, according to the results of confocal microscopy, BRCA1 also colocalizes with replicating Xi and autosomes revealed with BrdU in late S-phase of cell cycle. This indicates a possible involvement of this protein in the replication of pericentromeric repeats in cellular chromosomes. Colocalization of BRCA1 with heterochromatin protein-1α presented in pericentromeric regions of all chromosomes supports this suggestion.Conclusions . Altogether, the data obtained in this study suggest the involvement of BRCA1 in the inhibition of gene expression on Xi due to the association with noncoding inhibiting XIST RNA and in replication of heterochromatin regions. 

scholarly journals Lamin-binding Fragment of LAP2 Inhibits Increase in Nuclear Volume during the Cell Cycle and Progression into S Phase

1997 ◽  
Vol 139 (5) ◽  
pp. 1077-1087 ◽  
Author(s):  
Li Yang ◽  
Tinglu Guan ◽  
Larry Gerace
Keyword(s):  
Cell Cycle ◽  
Hela Cells ◽  
Nuclear Lamina ◽  
Normal Function ◽  
S Phase ◽  
Nuclear Volume ◽  
G1 Phase ◽  
Binding Region ◽  
Recombinant Polypeptide ◽  
Volume Increase

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.

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

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.

scholarly journals Growth factor, steroid, and steroid antagonist regulation of cyclin gene expression associated with changes in T-47D human breast cancer cell cycle progression.

1993 ◽  
Vol 13 (6) ◽  
pp. 3577-3587 ◽  
Author(s):  
E A Musgrove ◽  
J A Hamilton ◽  
C S Lee ◽  
K J Sweeney ◽  
C K Watts ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Cell Cycle ◽  
Cyclin D1 ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Cell Cycle Progression ◽  
S Phase ◽  
G1 Phase ◽  
Cycle Progression

Cyclins and proto-oncogenes including c-myc have been implicated in eukaryotic cell cycle control. The role of cyclins in steroidal regulation of cell proliferation is unknown, but a role for c-myc has been suggested. This study investigated the relationship between regulation of T-47D breast cancer cell cycle progression, particularly by steroids and their antagonists, and changes in the levels of expression of these genes. Sequential induction of cyclins D1 (early G1 phase), D3, E, A (late G1-early S phase), and B1 (G2 phase) was observed following insulin stimulation of cell cycle progression in serum-free medium. Transient acceleration of G1-phase cells by progestin was also accompanied by rapid induction of cyclin D1, apparent within 2 h. This early induction of cyclin D1 and the ability of delayed administration of antiprogestin to antagonize progestin-induced increases in both cyclin D1 mRNA and the proportion of cells in S phase support a central role for cyclin D1 in mediating the mitogenic response in T-47D cells. Compatible with this hypothesis, antiestrogen treatment reduced the expression of cyclin D1 approximately 8 h before changes in cell cycle phase distribution accompanying growth inhibition. In the absence of progestin, antiprogestin treatment inhibited T-47D cell cycle progression but in contrast did not decrease cyclin D1 expression. Thus, changes in cyclin D1 gene expression are often, but not invariably, associated with changes in the rate of T-47D breast cancer cell cycle progression. However, both antiestrogen and antiprogestin depleted c-myc mRNA by > 80% within 2 h. These data suggest the involvement of both cyclin D1 and c-myc in the steroidal control of breast cancer cell cycle progression.

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

1993 ◽  
Vol 71 (7-8) ◽  
pp. 372-380 ◽  
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.

Differentiation Profiling of Marrow Stem Cells: A Megakaryopoietic Hotspot and the Continuum Model of Hematopoiesis.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4217-4217
Author(s):  
Gerald A. Colvin ◽  
Dooner Gerri ◽  
Delia Demers ◽  
Shiela Pascual ◽  
Samuel Chung ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Stem Cells ◽  
S Phase ◽  
Platelet Glycoprotein ◽  
No Production ◽  
Colony Stimulating Factor ◽  
Hematopoietic Stem ◽  
Steel Factor ◽  
Stimulating Factor

Abstract Hierarchical models of hematopoiesis suppose an ordered system in which stem cells and progenitors with specific fixed differentiation potentials exist. We show here that the potential of marrow stem cells to differentiate changes reversibly with cytokine-induced cell cycle transit. This along with other data strongly suggest that stem cell regulation is not based on the classic hierarchical model, but instead more on a functional continuum We have previously shown that hematopoietic stem cells reversibly shift their engraftment phenotype with cytokine induced cell cycle transit. Further work has shown that adhesion protein, cytokine receptor, gene expression and progenitor phenotypes also shift. Evolving data indicate the phenotype of murine marrow stem cells reversible change with cell cycle transit. Murine experiments have been performed on highly purified, quiescent G0-1 lineagenegativerhodaminelowHoeschtlow (LRH) marrow stem cells. When exposed to thrombopoietin, FLT3-ligand and steel factor, they synchronously pass through cell cycle as measured by propidium iodide, cell doublings and tritiated thymidine. LRH cells enter S-phase in a synchronized fashion by 18 hours, leave S-phase at 40–42 hours and divide between 44–48 hours. The capacity of these cells to respond to a differentiation inductive signal (granulocyte colony-stimulating factor, granulocyte-macrophage colony stimulating factor and steel factor) is altered at different points in cell cycle. Megakaryocyte production is specifically focused at early to mid S-phase, this returned to baseline before the first cell division. Population based cultures after 14-days of differentiation culture produced up to 49% megakaryocytes with stem cells sub-cultured during early-mid S-phase with little to no production with colonies cultured from stem cells in G0-1 or G2 phase at time of differentiation induction signaling. Cell type was confirmed by staining cells with acetylcholinesterase, antibodies to platelet glycoprotein complex IIb/IIIa and von Willebrand’s factor. Evaluation of gene expression at this hotspot showed a marked increase in expression of CD4 with up to 464.2 fold increase above baseline. Sca-1 and transcriptional factor FOG was strikingly amplified at S-phase as well as other relevant markers. While pertinent cytokine receptors were not increased, studies on a clonal level confirm the existence of a reversible megakaryocytic hotspot. Compared with other time-points relating to cell cycle position prior to differentiation sub-culture in one experiment, 33% of clonally derived colonies that grew from early S-phase cells and 10% of colonies that grew from mid S-phase cells had megakaryocytes present two weeks after initiation of culture compared with 0% for G0-1 and G2 cells. Granulocyte differentiation also showed specific differentiation hotspots, but presentation is outside the scope of this abstract. These data indicate that marrow hematopoiesis stem cells exist in a continuum, not in a hierarchy with continuously changing windows of transcriptional opportunity.

HOXA6: A Novel Candidate Gene in AML.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2312-2312
Author(s):  
Glenda J. McGonigle ◽  
Damian P.J. Finnegan ◽  
Mary Frances McMullin ◽  
Terence R.J. Lappin ◽  
Alexander Thompson
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Growth Factor ◽  
Candidate Gene ◽  
Cell Lines ◽  
S Phase ◽  
Response To Therapy ◽  
Pcr Analysis ◽  
A6 Cells ◽  
Cell Cycle Status

Abstract Molecular classification of acute myeloid leukemia (AML) has identified several candidate genes that could potentially define prognosis and response to therapy. One such candidate, identified from microarray studies, is the Class I homeobox gene HOXA9. The HOX gene network encodes master regulators of developmental processes including hemopoiesis. To quantify the contribution of this network of genes in AML, we carried out specific RQ-PCR analysis on twenty-four de novo patient samples using a subset of genes (12 HOX and MEIS1) selected on the basis of their recently reported expression in AML. HOXA6 was ranked, as the most highly expressed gene (range 1 x 103 – 2 x 107 copies per 50 ng RNA), substantially higher than HOXA9 (see Table). Further analysis identified high expression of HOXA6 in both human myeloid cell lines and CD34+ enriched primary progenitors. Parallel studies with murine progenitors (c-Kit+, Lin−) and cell lines also showed a preponderance of Hoxa6 expression over other family members including Hoxa9 and Hoxb4. Several hemopoietic cell lines, namely Ba/F3, EML, FDCP-Mix A4 and 32Dcl3 were subsequently used to investigate Hoxa6 regulation following differentiation or growth factor stimuli. Hoxa6 expression decreased with cell differentiation and growth factor depletion/replenishment studies indicated a cell-cycle component for Hoxa6 regulation. Direct evaluation of cell-cycle status, using Hoechst 33342 staining and cell sorting, identified peak expression of Hoxa6 during S-phase. Gene deletion studies involving Hox tend to result in either a moderate or no phenotype, presumably due to intrinsic compensatory mechanisms. We therefore overexpressed HOXA6 in the Ba/F3 cell line to gain functional insights. Ba/F3-A6 cells were compared to mock-transfected and vector controls on the basis of proliferation, maturation, cell-cycle status, growth factor-dependence and apoptosis. The Ba/F3-A6 cells displayed a growth advantage over normal cells in the presence of IL-3 and maturation was not impaired. Cell-cycle analysis showed a reduction in the number of cells in both G2M and S-phase, associated with accumulation in the pre G1-phase, indicative of increased apoptosis. IL-3 depletion studies of Ba/F3-A6 cells indicated substantial factor-independent growth compared to controls, implying oncogenic potential for HOXA6. In support of this, a recent report (Mamo et al, Blood. 2006 Jul 15;108(2):622–9) indicated Hoxa6 as a potential collaborator in a Meis1-induced model of AML. Taken together these findings identify Hoxa6 as a novel candidate gene in AML with the capacity to alter growth and survival of hemopoietic cells. Gene Expression Ranking of HOX and MEIS1 in AML. GENE EXPRESSION RANGE MEAN RANK S.D. OVERALL RANK Expression values (copies per 50 ng RNA) compiled from primary AML patient samples (n=24) or * (n=12). S.D = standard deviation. HOXA6 1.2 x 103 – 1.7 x 107 2.2 1.6 1 HOXB3 9.3 x 101 – 8.4 x 106 3.2 2.5 2 HOXB2* 7.9 x 102 – 5.4 x 106 3.4 2.0 3 HOXA9 4.0 x 101 – 5.3 x 106 5.3 2.4 4 MEIS1 0.6 x 101 – 8.4 x 106 5.4 2.7 5 HOXA10* 2.4 x 102 – 1.7 x 105 5.5 3.2 6 HOXB4 1.5 x 102 – 7.8 x 105 5.5 3.2 7 HOXA7* 5.3 x 103 – 1.8 x 106 5.7 1.7 8 HOXB6 2.3 x 101 – 8.8 x 105 6.6 2.8 9 HOXA4 4.1 x 101 – 1.1 x 105 7.9 3.4 10 HOXA5* 3.4 x 101 – 4.3 x 104 9.3 2.8 11 HOXC6 1.0 x 101 – 3.2 x 103 9.7 2.3 12 HOXA11* 4.0 x 101 – 6.1 x 103 10.6 2.2 13

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

2019 ◽  
Vol 9 (2) ◽  
pp. 319-323 ◽  
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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