scholarly journals Proliferative activity of oocytes in multi-oocyte follicles of bovine ovary

2017 ◽  
Vol 38 (6) ◽  
pp. 3591
Author(s):  
Reginaldo Luis Oliveira ◽  
Katia Cristina Silva-Santos ◽  
Suellen Miguez Gonzalez ◽  
Camila Bizarro-Silva ◽  
Fernanda Zandonadi Machado ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Proliferative Activity ◽  
Nuclear Antigen ◽  
Proliferating Cells ◽  
Bovine Ovary

We characterized the proliferative activity of multi-oocyte follicles with anti-nuclear antigen of proliferating cells (PCNA). Ovaries (n = 12) from heifers were processed for histology. From 789 multi-oocytes follicles observed, only 11 were considered appropriated for immunostaining, since they presented all nuclei of the oocytes clearly visible. All multi-oocyte follicles were positive for PCNA, but some oocytes showed no proliferative activity. We conclude that oocytes in multi-oocyte follicles seem to be in different stages of the cell cycle.

Paralogs of Atlantic salmon myoblast determination factor genes are distinctly regulated in proliferating and differentiating myogenic cells

2010 ◽  
Vol 298 (6) ◽  
pp. R1615-R1626 ◽  
Author(s):  
Neil I. Bower ◽  
Ian A. Johnston
Keyword(s):  
Cell Cycle ◽  
Amino Acids ◽  
Amino Acid ◽  
Atlantic Salmon ◽  
Antigen Expression ◽  
Nuclear Antigen ◽  
Quiescent State ◽  
Mrna Levels ◽  
Proliferating Cells

The mRNA expression of myogenic regulatory factors, including myoD1 (myoblast determination factor) gene paralogs, and their regulation by amino acids and insulin-like growth factors were investigated in primary cell cultures isolated from fast myotomal muscle of Atlantic salmon ( Salmo salar). The cell cycle and S phase were determined as 28.1 and 13.3 h, respectively, at 18°C. Expression of myoD1b and myoD1c peaked at 8 days of culture in the initial proliferation phase and then declined more than sixfold as cells differentiated and was correlated with PCNA (proliferating cell nuclear antigen) expression ( R = 0.88, P < 0.0001; R = 0.70, P < 0.0001). In contrast, myoD1a transcripts increased from 2 to 8 days and remained at elevated levels as myotubes were formed. mRNA levels of myoD1c were, on average, 3.1- and 5.7-fold higher than myoD1a and myoD1b, respectively. Depriving cells of amino acids and serum led to a rapid increase in pax7 and a decrease in myoD1c and PCNA expression, indicating a transition to a quiescent state. In contrast, amino acid replacement in starved cells produced significant increases in myoD1c (at 6 h), PCNA (at 12 h), and myoD1b (at 24 h) and decreases in pax7 expression as cells entered the cell cycle. Our results are consistent with temporally distinct patterns of myoD1c and myoD1b expression at the G1 and S/G2 phases of the cell cycle. Treatment of starved cells with insulin-like growth factor I or II did not alter expression of the myoD paralogs. It was concluded that, in vitro, amino acids alone are sufficient to stimulate expression of genes regulating myogenesis in myoblasts involving autocrine/paracrine pathways. The differential responses of myoD paralogs during myotube maturation and amino acid treatments suggest that myoD1b and myoD1c are primarily expressed in proliferating cells and myoD1a in differentiating cells, providing evidence for their subfunctionalization following whole genome and local duplications in the Atlantic salmon lineage.

PCNA and total nuclear protein content as markers of cell proliferation in pea tissue

1992 ◽  
Vol 102 (1) ◽  
pp. 71-78 ◽  
Author(s):  
SANDRA CITTERIO ◽  
SERGIO SGORBATI ◽  
MARISA LEVI ◽  
BRUNO MARIA COLOMBO ◽  
ELIO SPARVOLI
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Protein Content ◽  
Time Course ◽  
Nuclear Protein ◽  
Flow Cytometric Analysis ◽  
Nuclear Antigen ◽  
Cycle Phase ◽  
Proliferating Cells ◽  
Embryo Cells

The identification of cell proliferation markers has been shown to be a useful tool with which to study basic mechanisms of cell cycle progression. The use of immunofluorescence techniques revealed the presence of the proliferating cell nuclear antigen (PCNA) in pea tissue, where we observed a high PCNA expression in proliferating cells of the root meristem compared to noncycling cells of the differentiated leaf. The presence of PCNA was monitored also during the time-course of seed germination, before, during and after the cell cycle resumption of the embryo cells. PCNA is present in embryo cells not only during and after resumption of the cell cycle but also before, when cells have not yet begun replicating their genome. A bivariate flow cytometric analysis of DNA and nuclear protein content was used to localize precisely the cells of the examined pea tissues in different cell cycle phase subcompartments. A high correlation was found between the degree of cell proliferation and the protein content of G1 nuclei, on the one hand, and the percentage of PCNA positive cells on the other.

scholarly journals p100: A Novel Proliferation-Associated Nuclear Protein Specifically Restricted to Cell Cycle Phases S, G2 , and M

Blood ◽  
1997 ◽  
Vol 90 (1) ◽  
pp. 226-233 ◽  
Author(s):  
H.J. Heidebrecht ◽  
F. Buck ◽  
J. Steinmann ◽  
R. Sprenger ◽  
H.H. Wacker ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Sorting ◽  
Cellular Proliferation ◽  
Protein Sequencing ◽  
Cancer Prognosis ◽  
Nuclear Antigen ◽  
Growth Fraction ◽  
Paraffin Sections ◽  
Proliferating Cells ◽  
Western Blots

By immunization with nuclear lysates of L428 cells, we raised a monoclonal mouse antibody, Ki-S2 (IgG1 ). In Western blots, this antibody recognizes a nuclear antigen with an apparent molecular mass of 100 kD, termed p100. Protein sequencing of p100 showed that this is a hitherto unknown protein. Immunohistochemical examination of cryostat and paraffin sections of nearly all human tissue types and neoplasms showed that p100 was exclusively expressed in the nuclei of a fraction of proliferating cells. Cell sorting and fluorescence-activated cell sorting analysis of stimulated peripheral blood mononuclear cells showed that p100 was exclusively expressed in proliferating cells from the transition G1/S until the end of cytokinesis. During mitosis, this protein is strictly associated with the spindle pole and with the mitotic spindle, whereas during S and G2 , p100 is diffusely distributed throughout the cell nucleus. Immediately after completion of cytokinesis, p100 was rapidly degraded. In L428 cells, p100 is phosphorylated at least during mitosis. It has a turnover time of about 1 hour. Studies on routinely processed paraffin sections of specimens of malignant lymphoma, benign and malignant nevocellular tumors, and breast cancer showed that in all cases less than 40% of the Ki-67–positive growth fraction expressed p100. Thus, p100 might prove to be a more reliable measure of cellular proliferation and one that is more closely correlated to cancer prognosis, beyond its general biologic relevance as a cell cycle protein.

Multiparameter Flow Cytometric Analysis of Neoplasms of the Central Nervous System: Correlation of Nuclear Antigen p105 and DNA Content with Clinical Behavior

Neurosurgery ◽  
1990 ◽  
Vol 27 (1) ◽  
pp. 83-96 ◽  
Author(s):  
Alan J. Appley ◽  
Patrick L. Fitzgibbons ◽  
Parakrama T. Chandrasoma ◽  
David R. Hinton ◽  
Michael L. J. Apuzzo
Keyword(s):  
Cell Cycle ◽  
Central Nervous System ◽  
Nervous System ◽  
Dna Content ◽  
Proliferative Activity ◽  
Pituitary Tumors ◽  
Nuclear Antigen ◽  
Clinical Behavior ◽  
The Central Nervous System ◽  
Well Differentiated

Abstract Analysis of the DNA content of various solid tumors and hematological malignancies may provide useful prognostic information. To date, however, there has been a striking lack of correlation between DNA content in neoplasms of the central nervous system and clinical behavior. Simultaneous quantitation of DNA content and proliferation-associated nuclear antigen (p105) by flow cytometry was performed on paraffin-embedded tissues representing three major groups of central nervous system neoplasms—1) 21 astrocytic tumors, 2) 13 pituitary tumors, and 3) 19 meningiomas-and the results were correlated with clinical behavior. All 4 well-differentiated gliomas were diploid, while 3 of 9 anaplastic astrocytomas and 1 of 8 glioblastomas had a demonstrable aneuploid peak. Three of 13 pituitary tumors had an identifiable aneuploid peak, while only 2 of 19 meningiomas had an aneuploid DNA content. Cell-cycle analysis of the malignant gliomas revealed a significantly higher proliferative index (PI, %S + G2M) compared with the well-differentiated astrocytomas (P&lt; 0.05). Within the subgroup of diploid anaplastic astrocytomas, however, extended patient survival appeared to be associated with a higher PI. For diploid pituitary adenomas, the PI was consistently lower in the 3 tumors that recurred than it was in the remaining 8 adenomas. Nuclear antigen quantitation of diploid tumors showed a wide range of p105 expression in G0G1cells, suggesting that, within each tumor, the cells are heterogeneous with respect to proliferative activity. Aneuploid nuclei of glial tumors showed enhanced expression of p105 relative to diploid cells of the same specimen. In pituitary tumors, the median G2M/G0G1fluorescence ratio for p105 was significantly higher (P&lt; 0.05) for the 3 diploid recurrent tumors than for those that did not recur. These data support the assumption that the aggressive clinical course of malignant glial neoplasms may be related to an abnormal DNA stemline and/or an alteration in cell proliferative activity. Cell cycle analysis and measurement of p105 by this technique may provide information useful from both a prognostic standpoint and in directing adjuvant therapy.

Ki-67 Labeling Index in Breast Cancer

1989 ◽  
Vol 75 (6) ◽  
pp. 557-562 ◽  
Author(s):  
Sergio Crispino ◽  
Ambrogio Brenna ◽  
Daniela Colombo ◽  
Bajardo Flores ◽  
Silvestro D'Amico ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Cycle ◽  
Monoclonal Antibody ◽  
Menopausal Status ◽  
Mitotic Rate ◽  
Labeling Index ◽  
Nuclear Antigen ◽  
Proliferating Cells ◽  
Cell Cycle Kinetics ◽  
Ki 67

Measurements of cell cycle kinetics have been found to correlate with the clinical course of patients with breast cancer. However, the thymidine labeling index and more rapid methods like flow cytometry remain complicated and costly. We assessed cell proliferation of 67 breast carcinomas by an immunoperoxidase procedure using a monoclonal antibody, Ki-67, which reacts with a nuclear antigen in proliferating cells. The percentage of Ki-67 positive cells ranged from 2% to 70 %. Tumors with high mitotic rate, high nuclear grade, high histologic grade, and negative estrogen receptors had statistically higher Ki-67 labeling rates. We found no significant differences between the Ki-67 labeling rate and other clinical (age at diagnosis, menopausal status) or pathologic (necrosis, fibrosis, vascular invasion, lymphatic invasion, cellular reaction, tumor size, lymph node metastases) features assessed. These results parallel previously reported data, and confirm that this immunohistochemical staining of breast carcinoma by Ki-67 monoclonal antibody can be considered a rapid and convenient method for assessing cell cycle kinetics. However, further studies, evaluating the correlation between Ki-67 labeling rate and prognosis are needed to better define the real usefulness of this analysis in clinical practice.

scholarly journals p100: A Novel Proliferation-Associated Nuclear Protein Specifically Restricted to Cell Cycle Phases S, G2 , and M

Blood ◽  
1997 ◽  
Vol 90 (1) ◽  
pp. 226-233 ◽  
Author(s):  
H.J. Heidebrecht ◽  
F. Buck ◽  
J. Steinmann ◽  
R. Sprenger ◽  
H.H. Wacker ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Sorting ◽  
Cellular Proliferation ◽  
Protein Sequencing ◽  
Cancer Prognosis ◽  
Nuclear Antigen ◽  
Growth Fraction ◽  
Paraffin Sections ◽  
Proliferating Cells ◽  
Western Blots

Abstract By immunization with nuclear lysates of L428 cells, we raised a monoclonal mouse antibody, Ki-S2 (IgG1 ). In Western blots, this antibody recognizes a nuclear antigen with an apparent molecular mass of 100 kD, termed p100. Protein sequencing of p100 showed that this is a hitherto unknown protein. Immunohistochemical examination of cryostat and paraffin sections of nearly all human tissue types and neoplasms showed that p100 was exclusively expressed in the nuclei of a fraction of proliferating cells. Cell sorting and fluorescence-activated cell sorting analysis of stimulated peripheral blood mononuclear cells showed that p100 was exclusively expressed in proliferating cells from the transition G1/S until the end of cytokinesis. During mitosis, this protein is strictly associated with the spindle pole and with the mitotic spindle, whereas during S and G2 , p100 is diffusely distributed throughout the cell nucleus. Immediately after completion of cytokinesis, p100 was rapidly degraded. In L428 cells, p100 is phosphorylated at least during mitosis. It has a turnover time of about 1 hour. Studies on routinely processed paraffin sections of specimens of malignant lymphoma, benign and malignant nevocellular tumors, and breast cancer showed that in all cases less than 40% of the Ki-67–positive growth fraction expressed p100. Thus, p100 might prove to be a more reliable measure of cellular proliferation and one that is more closely correlated to cancer prognosis, beyond its general biologic relevance as a cell cycle protein.

scholarly journals Repression of Epstein-Barr Virus EBNA-1 Gene Transcription by pRb during Restricted Latency

1999 ◽  
Vol 73 (10) ◽  
pp. 7943-7951 ◽  
Author(s):  
Ingrid K. Ruf ◽  
Jeffery Sample
Keyword(s):  
Cell Cycle ◽  
B Cells ◽  
Binding Sites ◽  
Epstein Barr Virus ◽  
Nuclear Antigen ◽  
Genome Replication ◽  
Mrna Levels ◽  
Proliferating Cells ◽  
Barr Virus ◽  
Epstein Barr

ABSTRACT During the restricted programs of Epstein-Barr virus (EBV) latency in EBV-associated tumors and a subpopulation of latently infected B cells in healthy EBV carriers, transcription of the EBV nuclear antigen 1 (EBNA-1) gene is mediated by the promoter Qp. Previously, two noncanonical E2F binding sites were identified within Qp. The role of E2F in the regulation of Qp, however, has been controversial and is undefined. Here we demonstrate that an E2F factor(s) within Burkitt lymphoma (BL) cells binds to a G/C-rich element [GGCG(C/G)] within the previously identified binding sites in Qp and prototypical E2F response elements. Furthermore, Qp-driven reporter gene expression could be efficiently repressed through either E2F binding site by the tumor suppressor pRb, a potent transcriptional repressor targeted to promoters during G0 and the early G1 phase of the cell cycle via its interaction with E2F; a mutant pRb (pRb706) lacking E2F binding capability was unable to repress Qp. However, we did not observe cell cycle variation in the expression of either EBNA-1 mRNA or protein in exponentially growing BL cells, consistent with previous predictions that Qp is constitutively active in these cells and with the extremely longt 1/2 of EBNA-1. By contrast, within G0/G1 in growth-arrested BL cells, EBNA-1 mRNA levels were twofold lower than in S phase, similar to the two- to eightfold differences in cell cycle expression of some cyclin mRNAs. Thus, although regulation of Qp is coupled to the cell cycle, this clearly has no impact on the level of EBNA-1 expressed in proliferating cells. We conclude, therefore, that the most important contribution of E2F to the regulation of Qp is to direct the pRb-mediated suppression of EBNA-1 expression within resting B cells, the principal reservoir of latent EBV. This would provide a means to restrict unneeded and potentially deleterious expression of EBNA-1 in a nonproliferating cell and to coordinate the activation of EBNA-1 expression necessary for EBV genome replication and maintenance upon reentry of the cell cycle in response to proliferative signals.

scholarly journals Regulation of DNA Replication Licensing and Re-Replication by Cdt1

2021 ◽  
Vol 22 (10) ◽  
pp. 5195
Author(s):  
Hui Zhang
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Dna Replication ◽  
Genome Stability ◽  
E3 Ligase ◽  
S Phase ◽  
Replication Initiation ◽  
Nuclear Antigen ◽  
Repair Synthesis ◽  
Ubiquitin E3 Ligase

In eukaryotic cells, DNA replication licensing is precisely regulated to ensure that the initiation of genomic DNA replication in S phase occurs once and only once for each mitotic cell division. A key regulatory mechanism by which DNA re-replication is suppressed is the S phase-dependent proteolysis of Cdt1, an essential replication protein for licensing DNA replication origins by loading the Mcm2-7 replication helicase for DNA duplication in S phase. Cdt1 degradation is mediated by CRL4Cdt2 ubiquitin E3 ligase, which further requires Cdt1 binding to proliferating cell nuclear antigen (PCNA) through a PIP box domain in Cdt1 during DNA synthesis. Recent studies found that Cdt2, the specific subunit of CRL4Cdt2 ubiquitin E3 ligase that targets Cdt1 for degradation, also contains an evolutionarily conserved PIP box-like domain that mediates the interaction with PCNA. These findings suggest that the initiation and elongation of DNA replication or DNA damage-induced repair synthesis provide a novel mechanism by which Cdt1 and CRL4Cdt2 are both recruited onto the trimeric PCNA clamp encircling the replicating DNA strands to promote the interaction between Cdt1 and CRL4Cdt2. The proximity of PCNA-bound Cdt1 to CRL4Cdt2 facilitates the destruction of Cdt1 in response to DNA damage or after DNA replication initiation to prevent DNA re-replication in the cell cycle. CRL4Cdt2 ubiquitin E3 ligase may also regulate the degradation of other PIP box-containing proteins, such as CDK inhibitor p21 and histone methylase Set8, to regulate DNA replication licensing, cell cycle progression, DNA repair, and genome stability by directly interacting with PCNA during DNA replication and repair synthesis.

scholarly journals Ano1 as a regulator of proliferation

2011 ◽  
Vol 301 (6) ◽  
pp. G1044-G1051 ◽  
Author(s):  
Jennifer E. Stanich ◽  
Simon J. Gibbons ◽  
Seth T. Eisenman ◽  
Michael R. Bardsley ◽  
Jason R. Rock ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Slow Wave ◽  
Interstitial Cells Of Cajal ◽  
Primary Cultures ◽  
Channel Blockers ◽  
Proliferating Cells ◽  
Stromal Tumors ◽  
Whole Mount ◽  
Cells Of Cajal ◽  
Regular Medium

Ano1 is a recently discovered Ca2+-activated Cl− channel expressed on interstitial cells of Cajal (ICC) that has been implicated in slow-wave activity in the gut. However, Ano1 is expressed on all classes of ICC, even those that do not contribute to generation of the slow wave, suggesting that Ano1 may have an alternate function in these cells. Ano1 is also highly expressed in gastrointestinal stromal tumors. Mice lacking Ano1 had fewer proliferating ICC in whole mount preparations and in culture, raising the possibility that Ano1 is involved in proliferation. Cl− channel blockers decreased proliferation in cells expressing Ano1, including primary cultures of ICC and in the pancreatic cancer-derived cell line, CFPAC-1. Cl− channel blockers had a reduced effect on Ano1(−/−) cultures, confirming that the blockers are acting on Ano1. Ki67 immunoreactivity, 5-ethynyl-2′-deoxyuridine incorporation, and cell-cycle analysis of cells grown in low-Cl− media showed fewer proliferating cells than in cultures grown in regular medium. We confirmed that mice lacking Ano1 had less phosphorylated retinoblastoma protein compared with controls. These data led us to conclude that Ano1 regulates proliferation at the G1/S transition of the cell cycle and may play a role in tumorigenesis.

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