scholarly journals The cell proliferation-associated antigen of antibody Ki-67: a very large, ubiquitous nuclear protein with numerous repeated elements, representing a new kind of cell cycle-maintaining proteins.

1993 ◽  
Vol 123 (3) ◽  
pp. 513-522 ◽  
Author(s):  
C Schlüter ◽  
M Duchrow ◽  
C Wohlenberg ◽  
M H Becker ◽  
G Key ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Nuclear Protein ◽  
Open Reading Frames ◽  
Growth Fraction ◽  
Proliferating Cells ◽  
Ki 67 ◽  
Nonhistone Proteins ◽  
Molecular Weights ◽  
Absolute Requirement

The antigen defined by mAb Ki-67 is a human nuclear protein the expression of which is strictly associated with cell proliferation and which is widely used in routine pathology as a "proliferation marker" to measure the growth fraction of cells in human tumors. Ki-67 detects a double band with apparent molecular weights of 395 and 345 kD in immunoblots of proteins from proliferating cells. We cloned and sequenced the full length cDNA, identified two differentially spliced isoforms of mRNA with open reading frames of 9,768 and 8,688 bp encoding for this cell proliferation-associated protein with calculated molecular weights of 358,761 D and 319,508 D, respectively. New mAbs against a bacterially expressed part and a synthetic polypeptide deduced from the isolated cDNA react with the native Ki-67 antigen, thus providing a circle of evidence that we have cloned the authentic Ki-67 antigen cDNA. The central part of the Ki-67 antigen cDNA contains a large 6,845-bp exon with 16 tandemly repeated 366-bp elements, the "Ki-67 repeats", each including a highly conserved new motif of 66 bp, the "Ki-67 motif", which encodes for the epitope detected by Ki-67. Computer analysis of the nucleic acid and the deduced amino acid sequence of the Ki-67 antigen confirmed that the cDNA encodes for a nuclear and short-lived protein without any significant homology to known sequences. Ki-67 antigen-specific antisense oligonucleotides inhibit the proliferation of IM-9 cell line cells, indicating that the Ki-67 antigen may be an absolute requirement for maintaining cell proliferation. We conclude that the Ki-67 antigen defines a new category of cell cycle-associated nuclear nonhistone proteins.

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.

The murine Ki-67 cell proliferation antigen accumulates in the nucleolar and heterochromatic regions of interphase cells and at the periphery of the mitotic chromosomes in a process essential for cell cycle progression

1996 ◽  
Vol 109 (1) ◽  
pp. 143-153 ◽  
Author(s):  
M. Starborg ◽  
K. Gell ◽  
E. Brundell ◽  
C. Hoog
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Tandem Repeats ◽  
Sequence Motifs ◽  
Mitotic Chromosomes ◽  
Proliferating Cells ◽  
Ki 67 ◽  
Cycle Progression ◽  
Conserved Sequence ◽  
Interphase Cells

We have isolated the murine homologue of the human Ki-67 antigen. The Ki-67 antigen is used as a marker to assess the proliferative capacity of tumour cells; however, its cellular function is not known. The murine Ki-67 cDNA sequence (TSG126) was found to contain 13 tandem repeats, making up more than half of the total protein size. A comparison of this repetitive sequence block to its human counterpart, which contains 16 consecutive repeat units, revealed several conserved sequence motifs, including one motif frequently observed in proteins interacting with DNA. An antiserum developed against the product of the TSG126 cDNA clone identified a protein with an apparent molecular mass of 360 kDa, mainly expressed in proliferating cells. The TSG126 protein begins to accumulate during the late G1 stage of the cell cycle and is first seen as numerous small granules evenly distributed throughout the nucleus. During the S and the G2 phases, larger foci that overlap with the nucleoli and the heterochromatic regions are formed. At the onset of mitosis the TSG126 protein undergoes a dramatic redistribution process and becomes associated with the surface of the condensed chromosomes. The relative absence of the TSG126 protein from G1 interphase cells strongly argues against a model where the association of the TSG126 protein with mitotic chromosomes merely reflects a mechanism for the symmetrical distribution of nucleolar proteins between daughter cells. Instead, the intracellular distribution of the TSG126 protein during the cell cycle suggests that it could have a chromatin-associated function in both interphase and mitotic cells. Microinjection of anti-TSG126 antibodies into proliferating Swiss-3T3 fibroblasts was found to delay cell cycle progression, indicating that the TSG126 protein has an essential nuclear function.

scholarly journals Translocation of protein tyrosine phosphatase Pez/PTPD2/PTP36 to the nucleus is associated with induction of cell proliferation

2000 ◽  
Vol 113 (17) ◽  
pp. 3117-3123 ◽  
Author(s):  
C. Wadham ◽  
J.R. Gamble ◽  
M.A. Vadas ◽  
Y. Khew-Goodall
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
Nuclear Protein ◽  
Vascular Endothelial Cells ◽  
Tyrosine Phosphatase ◽  
Subcellular Localisation ◽  
Vascular Endothelial ◽  
Proliferating Cells ◽  
Wound Edge

Pez is a non-transmembrane tyrosine phosphatase with homology to the FERM (4.1, ezrin, radixin, moesin) family of proteins. The subcellular localisation of Pez in endothelial cells was found to be regulated by cell density and serum concentration. In confluent monolayers Pez was cytoplasmic, but in cells cultured at low density Pez was nuclear, suggesting that it is a nuclear protein in proliferating cells. This notion is supported by the loss of nuclear Pez when cells are serum-starved to induce quiescence, and the rapid return of Pez to the nucleus upon refeeding with serum to induce proliferation. Vascular endothelial cells normally exist as a quiescent confluent monolayer but become proliferative during angiogenesis or upon vascular injury. Using a ‘wound’ assay to mimic these events in vitro, Pez was found to be nuclear in the cells that had migrated and were proliferative at the ‘wound’ edge. TGFbeta, which inhibits cell proliferation but not migration, inhibited the translocation of Pez to the nucleus in the cells at the ‘wound’ edge, further strengthening the argument that Pez plays a role in the nucleus during cell proliferation. Together, the data presented indicate that Pez is a nuclear tyrosine phosphatase that may play a role in cell proliferation.

Expression of Cell Cycle Regulatory Proteins and Analysis of Apoptosis in Normal Nasal Mucosa and in Nasal Polyps

2005 ◽  
Vol 19 (6) ◽  
pp. 549-553 ◽  
Author(s):  
Werner Garavello ◽  
Paola Viganò ◽  
Marco Romagnoli ◽  
Lorenza Sordo ◽  
Emilio Berti ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Nasal Mucosa ◽  
Nasal Polyps ◽  
Normal Mucosa ◽  
Cellular Growth ◽  
Regulatory Proteins ◽  
Biological Behavior ◽  
Proliferating Cells ◽  
Ki 67 ◽  
Sequence Of Events

Background The etiopathogenesis of nasal polyps still is to be clarified. Although hyperplasia is a typical feature of these pathological processes, little attention has been paid to specific aspects of cellular growth in polyps. We have evaluated the expression and localization of some of the regulatory proteins that direct the cell through the specific sequence of events culminating in mitosis or apoptosis in nasal polyps. Methods Twenty samples of nasal polyps and 20 samples of normal nasal mucosa have been analyzed for apoptotic index by detecting the DNA 3’ OH ends deriving from DNA fragmentation. Moreover, they have been evaluated by immunohistochemical staining for expression of Ki-67, cyclins A and B1, p53, p21, p27, murine double minute clone 2, and Bcl-2. Results We have identified a greater proportion of proliferating cells in the lining epithelial cells of the polyps when compared with the normal mucosa as stained with anti–Ki-67 antibodies. An overexpression of p53, MDM2, and Bcl-2 and an increased apoptosis were observed in nasal polyps compared with the normal mucosa, whereas no variation of p27 expression was observed. The p21 and cyclins A and B1 were rarely expressed in both pathological and normal tissue. Conclusion The p53-based control system of cell cycle progression appears to be altered in nasal polyps, potentially leading to an abrogation of the DNA damage checkpoint. Evaluation of the expression of the regulatory proteins that direct the cells throughout their cycle in nasal polyps may allow a better understanding of the biological behavior and clinical outcome of these benign pathological entities.

scholarly journals Evolutionary conservation in various mammalian species of the human proliferation-associated epitope recognized by the Ki-67 monoclonal antibody.

1989 ◽  
Vol 37 (10) ◽  
pp. 1471-1478 ◽  
Author(s):  
B Falini ◽  
L Flenghi ◽  
M Fagioli ◽  
H Stein ◽  
R Schwarting ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Cell Proliferation ◽  
Mammalian Species ◽  
Calf Serum ◽  
Evolutionary Conservation ◽  
Resting Cells ◽  
Nuclear Staining ◽  
Proliferating Cells ◽  
Ki 67

The human proliferation-associated epitope recognized by the Ki-67 monoclonal antibody (MAb) was detected in proliferating normal and neoplastic cells of many mammalian species (lamb, calf, dog, rabbit, rat) besides human. In contrast, Ki-67 stained proliferating cells from other species weakly (mouse) or not at all (swine, cat, chicken, pigeon). The immunostaining pattern of Ki-67 in animal tissues was identical to that previously described in human: Ki-67 reacted only with cells known to proliferate (e.g., germinal center cells, cortical thymocytes) but not with resting cells (e.g., hepatocytes, brain cells, renal cells); this MAb produced a characteristic nuclear staining pattern (e.g., stronger labeling of nucleoli than of the rest of the nuclei and staining of chromosomes in mitotic figures); and Ki-67 crossreacted with the squamous epithelium in both animal and human tissues. In vitro studies showed that when quiescent (Ki-67-negative) NIH 3T3 fibroblasts or bovine peripheral blood lymphocytes were induced to proliferate, the appearance of Ki-67-positive cells paralleled the induction of cell proliferation caused by addition of fetal calf serum or PHA, respectively, to the cultures, and in both human and rat proliferating cells the Ki-67 expression closely paralleled the incorporation of [3H]-thymidine. These findings indicate that the epitope recognized by the Ki-67 MAb in human and animal species is the same. The widespread evolutionary conservation of the human proliferation-associated epitope recognized by the Ki-67 MAb suggests that it and/or its carrier molecule may play an important role in regulation of cell proliferation.

scholarly journals The effects of 5α-dihydrotestosterone on the kinetics of cell proliferation in rat prostate

1974 ◽  
Vol 142 (3) ◽  
pp. 483-489 ◽  
Author(s):  
Barry Lesser ◽  
Nicholas Bruchovsky
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cellular Growth ◽  
Velocity Sedimentation ◽  
Growth Fraction ◽  
Subcutaneous Injections ◽  
Daughter Cells ◽  
A Cell ◽  
Rat Prostate ◽  
Kinetics Of

The regenerating rat prostate was used as an experimental model to determine the effects of 5α-dihydrotestosterone on certain parameters of cell proliferation, including the duration of the phases of the cell cycle and the size of the cellular growth fraction. Rats castrated 7 days previously were treated with daily subcutaneous injections of 5α-dihydrotestosterone for 14 days; 48h after the beginning of therapy, cells in the process of DNA synthesis were labelled with a single injection of radioactive thymidine and the progress of these cells through the division cycle was observed. Cell-cycle analysis was performed by fractionating prostatic nuclei according to their position in the cell cycle by using the technique of velocity sedimentation under unit gravity. The results indicate that during regeneration the cell population undergoes 1.8 doublings with a doubling time of 40h, and that the process involves almost four rounds of cell division with a cell-generation time of 20h. The growth fraction at any time is about 0.5, and about half the daughter cells produced do not re-enter the proliferative cycle. All cells present at the start of regeneration eventually undergo at least one division during the course of regeneration, although any given cell can divide from one to four times.

Cell Proliferation in Retinal Transplants

1997 ◽  
Vol 6 (2) ◽  
pp. 141-148 ◽  
Author(s):  
Rajesh K. Sharma ◽  
Berndt Ehinger
Keyword(s):  
Cell Proliferation ◽  
Nuclear Protein ◽  
Subretinal Space ◽  
Ki 67 ◽  
Equivalent Age ◽  
Dividing Cells ◽  
Long Time ◽  
Graft Interface ◽  
Retinal Transplants ◽  
Mib 1

The MIB-1 antibody against a nuclear protein Ki-67 was used to study the proliferation of cells in the rabbit retinal transplants. Fragmented pieces of embryonic day 15 rabbit retinas were transplanted into the subretinal space of adult rabbits and allowed to survive for different times. Fragmented donor tissue starts organizing in rosettes 1 day after transplantation. The transplanted cells continue to proliferate in the host eye and their pattern of proliferation resembles that of normal developing retina, suggesting that the factors responsible for the proliferation pattern are preserved after transplantation. The dividing cells in metaphase line up in the luminal layers of the rosettes. Certain cells become postmitotic in the regions corresponding to the inner retina first, followed by the cells in the luminal layers of rosettes. Cells in the regions between the rosettes, corresponding to the inner nuclear layer, presumably the Müller cells, proliferate significantly for the equivalent age of postnatal day 2. Few cells in these regions proliferate for at least the equivalent age of postnatal day 11 in transplants. There is a layer of nonproliferating, degenerating cells in the transplant situated close to the host retina. However, some cells in this layer, situated at the host-graft interface, proliferate. These cells proliferate for a long time possibly indicating gliosis.

The Effect of miR-155 on the Regulation of Hyperplasia of Middle Membrane of Blood Vessel in Rat Hypertension Model

2019 ◽  
Vol 9 (7) ◽  
pp. 982-987
Author(s):  
Xiaoying Wang ◽  
Yanke Hao
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Bioinformatics Analysis ◽  
Luciferase Assay ◽  
Ki 67 ◽  
Vsmc Proliferation ◽  
Tunica Media ◽  
Proliferation And Apoptosis ◽  
The Relationship

Vascular smooth muscle cell (VSMC) abnormal proliferation is related to hypertension. P27 can arrest cell cycle and its downregulation is associated with hypertension. miR-155 plays a regulatory role in VSMC proliferation, while its relationship with hypertension is still unclear. Bioinformatics analysis reveals a relationship between p27 mRNA and miR-155. The present study explores miR-155's role in p27 expression, VSMC proliferation and apoptosis, as well as in the pathogenesis of hypertension. Dual luciferase assay verified the relationship between miR-155 and p27. miR155, p27, α-SMA, and Ki-67 expressions in the thoracic aorta media of rat hypertension model were detected. VSMCs were cultured in vitro and grouped into, anti-miR-NC, anti-miR-155, pIRES2-blank, pIRES2-p27, and anti-miR-155 + pIRES2-p27 groups followed by analysis of cell cycle by flow cytometry and cell proliferation by EdU staining. Hypertension rats were randomly divided into antagomir-155 and antagomir-control. Caudal artery systolic and diastolic pressures were measured. miR-155 suppressed p27 expression. miR-155 and Ki-67 expressions were significantly enhanced, while p27 and α-SMA levels were reduced in the tunica media from hypertension rats compared with control. Downregulation of miR-155 and/or upregulation of p27 obviously declined cell proliferation and arrested cell cycle in G1 phase. Antagomir-155 injection significantly decreased systolic and diastolic pressures, elevated p27 and α-SMA expressions in media, and reduced the thickness of tunica media. miR-155 enhances VSMC proliferation via regulating p27. miR-155 enhancement was related to hypertension. miR-155 plays a therapeutic effect in hypertension.

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.

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