Search Results
Results 401 - 450 of 1778
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Mourant J R - - 2002
We demonstrate that the effects of cell-cell contact and of changes in cell shape have only a minor effect on the angular distribution of light scattering from mammalian fibroblast cells. This result is important for the development of light scattering as a noninvasive tool for tissue diagnostics such as cancer ...
Cloos Jacqueline - - 2002
Bleomycin-induced chromosomal instability, generally referred to as mutagen sensitivity, is associated with an increased risk for the development of environmentally related cancer including head and neck squamous cell carcinoma and lung cancer. On average, the cultured lymphocytes of patients with these types of cancer show an increased number of chromatid ...
Bozko Przemyslaw - - 2002
We here report the influence of the cell cycle abrogator UCN-01 on RKO human colon carcinoma cells differing in p53 status following exposure to two DNA damaging agents, the topoisomerase inhibitors etoposide and camptothecin. Cells were treated with the two drugs at the IC90 concentration for 24 h followed by ...
Kiyota Akihisa - - 2002
Epidermal growth factor receptor (EGFR) regulates the growth and progression of human oral squamous cell carcinoma (SCC). Recently, the link between EGFR signaling and the cell cycle has been identified. Some reports have described that EGFR-blocking monoclonal antibody 225 (mAb225) induced G1 arrest and inhibited the growth of various cancer ...
Swiatek Agnieszka - - 2002
Environmental stress affects plant growth and development. Several plant hormones, such as salicylic acid, abscisic acid (ABA), jasmonic acid (JA), and ethylene play a crucial role in altering plant morphology in response to stress. Developmental regulation often has the cell cycle machinery among its targets. We analyzed the effect of ...
Kimura S - - 2001
The biochemical and cell cycle-dependent properties of proliferating cell nuclear antigen (OsPCNA) and flap endonuclease-1 (OsFEN-1) were characterized from rice (Oryza sativa). OsPCNA was physically associated with OsFEN-1 and increased the flap-endonuclease activity of OsFEN-1 by 2.5-fold. Northern and Western blotting analysis revealed that OsPCNA and OsFEN-1 were present in ...
Erenpreisa Jekaterina - - 2001
Mitotic death is a delayed response of p53 mutant tumours that are resistant to genotoxic damage. Questions surround why this response is so delayed and how its mechanisms serve a survival function. After uncoupling apoptosis from G1 and S phase arrests and adapting these checkpoints, p53 mutated tumour cells arrive ...
de Noronha C M - - 2001
Human immunodeficiency virus-1 (HIV-1) Vpr expression halts the proliferation of human cells at or near the G2 cell-cycle checkpoint. The transition from G2 to mitosis is normally controlled by changes in the state of phosphorylation and subcellular compartmentalization of key cell-cycle regulatory proteins. In studies of the intracellular trafficking of ...
Frykman S - - 2001
Synchronized Saccharomyces cerevisiae cell populations were used to examine secretion rates of a heterologous protein as a function of cell cycle position. The synchronization procedure had a profound effect on the type and quality of data obtained. When cell synchrony was induced by cell cycle-arresting drugs, a significant physiological perturbation ...
Jung E J - - 2001
We have previously provided evidence that the uptake of DNA into cells is cell cycle specific following transfection. We show here that, immediately after transfection, successfully transfected cells are greatly enriched for cells in early G1 or G0 phase and that, upon removal of the DNA precipitates, cells progress through ...
Hagiwara S - - 2001
Effects of light and darkness on cell-cycle progression were studied in the log-linear photoautotrophic growth mode of Euglena gracilis. We found that there are light-dependent restriction points in the post-G1 phases, quite in contrast to Chlamydomonas, where a light-dependent restriction is known to exist only in the G1 phase. Thus, ...
Qin J - - 2001
OBJECTIVE: To establish a new method for analyzing the cell cycle in tumor which is a kind of cell cycle disease. METHODS: Mixtures of cyclin E and cyclin A antibodies were incubated with fixed MOLT-4 cells, and measured by flow cytometry. RESULTS: We developed a cyclin E + A/DNA flow ...
Yin M - - 2001
Promotion of apoptosis may potentiate the sensitivity of tumor cells to chemotherapeutic agents, thus improving the efficacy of cancer treatment. The transfection of the proapoptotic bax gene, which results in the overexpression of bax protein, augments the growth inhibition of A253 cells by BNP1350. Increased drug response was associated with ...
Ng S S - - 2001
In the fission yeast Schizosaccharomyces pombe Mik1p, in combination with Wee1p, is an important inhibitor of mitosis through direct phosphorylation of Cdc2p. Here we present the observation that mik1(+) is transcribed during G1- and S-phase in normally dividing cells. mik1(+) transcription is regulated by the MCB-DSC1 system, which controls expression ...
Kao G D - - 2001
All eukaryotic cells manifest cell cycle delay after exposure to DNA damaging agents. It has been proposed that such cell cycle checkpoints may allow DNA repair but direct evidence of such activity during the radiation-induced G2 delay has been lacking. We report here that cells arrested in G2 by radiation ...
Alic N - - 2001
Reactive oxygen species cause damage to all of the major cellular constituents, including peroxidation of lipids. Previous studies have revealed that oxidative stress, including exposure to oxidation products, affects the progression of cells through the cell division cycle. This study examined the effect of linoleic acid hydroperoxide, a lipid peroxidation ...
Khan Q A - - 2001
In previous studies using human breast carcinoma cells (MCF-7) and human colon carcinoma cells (RKO) we have shown that, in response to treatment with hydrocarbon carcinogens, these cell lines failed to undergo a p53-mediated cell cycle arrest in G1 phase; rather, the cells were accumulated in the S phase with ...
Drayson M T - - 2001
When 1 alpha,25-dihydroxyvitamin D(3) (D(3)) induces HL60 cells to differentiate to monocytes, a burst of approximately three shortened cell cycles ("maturation divisions") precedes exit from cell cycle and completion of maturation. Here we show that similar maturation divisions occur during neutrophil differentiation induced by all-trans-retinoic acid (ATRA), but without shortening ...
Casagrande F - - 2001
We have investigated the effects of a series of flavonoids on cell proliferation and cell cycle distribution in human melanoma cells OCM-1. Among the compounds that potently inhibited OCM-1 cell proliferation, we show that the presence of a hydroxyl group at the 3'-position of the ring B in quercetin and ...
Jackman J - - 2001
Exponentially growing cells are asynchronous with respect to the cell cycle stage. Detection of cell cycle-related events is improved by enriching the culture for cells at the stage during which the particular event occurs. Methods for synchronizing cells are provided here, including those based on morphological features of the cell ...
Kühholzer B - - 2001
Proper synchronization of donor nuclei has been shown to have a major influence on the developmental potential of nuclear transfer embryos. In the present study, a protocol was established to synchronize porcine fetal fibroblasts in the G2 stage of the cell cycle. Cell cycle analyses were performed by flow cytometry. ...
Gewirtz D A - - 2001
This report characterizes the influence of a pharmacological concentration of estradiol on growth arrest and cell death in MCF-7 breast tumor cells, with a focus on elements of the Rb-E2F cell-cycle regulatory pathway. Continuous exposure of MCF-7 breast tumor cells to 100 microM estradiol produces a marked reduction in the ...
Ganapati U - - 2001
PTP-S2 is a ubiquitously expressed nuclear protein tyrosine phosphatase which shows increased expression upon mitogenic stimulation in a variety of cells in vitro and in vivo. In order to understand the role of this enzyme in cell cycle progression, tetracycline-regulated HeLa clones expressing PTP-S2 were isolated and characterized. Tetracycline-controlled expression ...
Hassan P - - 2001
The Leishmania mexicana CRK3 gene encodes a cdc2-related protein kinase with activity towards histone H1. Attempts to disrupt both alleles of CRK3 in the promastigote life-cycle stage resulted in changes in cell ploidy, which were avoided only when an extra copy of CRK3 was expressed from an episome. This provides ...
Rancourt R C - - 2001
Previous studies have shown that hyperoxia inhibits proliferation and increases the expression of the tumor suppressor p53 and its downstream target, the cyclin-dependent kinase inhibitor p21(CIP1/WAF1), which inhibits proliferation in the G1 phase of the cell cycle. To determine whether growth arrest was mediated through activation of the p21-dependent G1 ...
Azhar M - - 2001
In Dictyostelium discoideum, the initial differentiation of cells is regulated by the phase of the cell cycle at starvation. Cells in S and early G2 (or with a low DNA content) have relatively high levels of cellular Ca2+ and display a prestalk tendency after starvation, whereas cells in mid to ...
Anderson S C - - 2001
PURPOSE: It has been recognized that an increased expression of the Rho-associated kinase (ROCK-I), a downstream target of Rho (a Ras-related small guanosine triphosphatase [GTPase]), is associated with limbal-to-corneal epithelial transition. The purpose of the present study was to determine whether the expression of ROCK-I is regulated during the cell ...
Takeuchi J - - 2001
Rpn9 is one of the subunits of the regulatory particle of the yeast 26S proteasome and is needed for stability or efficient assembly of the 26S proteasome. As anticipated from the fact that the rpn9 disruptant grew at 25 degrees C but arrested in G2/M phase at 37 degrees C, ...
Hitomi M - - 2001
Synchronization used to study cell cycle progression may change the characteristics of rapidly proliferating cells. By combining time-lapse, quantitative fluorescent microscopy and microinjection, we have established a method to analyze the cell cycle progression of individual cells without synchronization. This new approach revealed that rapidly growing NIH3T3 cells make a ...
Kondo T - - 2001
pRB family pocket proteins consisting of pRB, p107, and p130 are thought to act as a set of growth regulators that inhibit the cell cycle transition from G1 to S phases by virtue of their interaction with E2F transcription factors. When cells are committed to progressing through the cell cycle ...
Mizukoshi E - - 2001
We previously reported that endogenously expressed, intracellularly localized fibroblast growth factor (FGF)-1 interacts with mortalin. Here we report that FGF-1 added to the culture medium of quiescent BALB/c3T3 cells is taken up by the cells and interacts with mortalin in the cells in a regulated manner. Although both the internalized ...
Nishida K - - 2001
Two distinct types of Balb / 3T3 cells were isolated which exhibit either 4 N DNA or both 4 N and 8 N DNA after exposure to colcemid for 48 h. They were found to differ with respect to the postmitotic checkpoint, but not the mitotic checkpoint. Firstly, the checkpoint-proficient ...
Bellí G - - 2001
Moderate hyperosmotic stress on Saccharomyces cerevisiae cells produces a temporary delay at the G1 stage of the cell cycle. This is accompanied by transitory downregulation of CLN1, CLN2 and CLB5 transcript levels, although not of CLN3, which codes for the most upstream activator of the G1/S transition. Osmotic shock to ...
Shi Z - - 2001
The mechanisms of resistance to nucleoside analogues established in preclinical models are rarely found in primary tumors resistant to therapy with these agents. We tested the hypothesis that cells sense sublethal incorporation of analogues into DNA during replication and react by arresting further DNA synthesis and cell cycle progression. After ...
Jacquet S - - 2001
The effect of light on the synchronization of cell cycling was investigated in several strains of the oceanic photosynthetic prokaryote Prochlorococcus using flow cytometry. When exposed to a light-dark (L-D) cycle with an irradiance of 25 micromol of quanta x m(-2) x s(-1), the low-light-adapted strain SS 120 appeared to ...
Pincheira J - - 2001
The high frequency of chromosomal breaks in Fanconi anemia (FA) lymphocytes has been related to the increased oxidative damage shown by these cells. The effect of 100 microM DL-alpha-tocopherol (Vitamin E) on the level of chromosomal damage in mitosis was studied in lymphocytes from five FA patients and from age ...
Minemoto Y - - 2001
We investigated the effect of Adriamycin on FL-amnion (FL) cells. After treatment with the drug, the cells arrested at G2, but we did not detect an increase in the p21 levels. We established a p53-deficient derivative of these cells, in which G2 arrest also occurred after treatment with Adriamycin, suggesting ...
Zimmerman Z A - - 2001
We have used affinity chromatography to identify proteins that interact with Nap1, a protein previously shown to play a role in mitosis. Our studies demonstrate that a highly conserved protein called Sda1 binds to Nap1 both in vitro and in vivo. Loss of Sda1 function causes cells to arrest uniformly ...
Wang N - - 2001
The cytosolic thymidine kinase 1 (TK1) is one of the enzymes involved in DNA replication. Based on biochemical studies, TK1 is activated at late G1 of cell cycle, and its activity correlates with the cell proliferation. We have developed a polyclonal anti-TK1 antibody against a synthetic peptide from the C-terminus ...
Lin M L - - 2001
p55Cdc/Cdc20 is expressed in cycling mammalian cells and has been shown to be an activator of the mitotic spindle assembly checkpoint. We previously showed that overexpression of p55Cdc/Cdc20 in myeloid cells resulted in accelerated apoptosis and inhibition of granulocyte differentiation in the murine myeloid cell line 32Dcl3. p55Cdc/Cdc20 protein expression ...
Hulleman E - - 2001
Cell cycle progression is regulated by both intracellular and extracellular control mechanisms. Intracellular controls ensure that cell cycle progression is stopped in response to irregularities such as DNA damage or faulty spindle assembly, whereas extracellular factors may determine cell fate such as differentiation, proliferation or programmed cell death (apoptosis). When ...
Kikkert M - - 2001
The glycoprotein precursor (G1/G2) gene of tomato spotted wilt virus (TSWV) was expressed in BHK cells using the Semliki Forest virus expression system. The results reveal that in this cell system, the precursor is efficiently cleaved and the resulting G1 and G2 glycoproteins are transported from the endoplasmic reticulum (ER) ...
West A - - 2001
In response to induced DNA damage, proliferating cells arrest in their cell cycle or go into apoptosis. Ionizing radiation is known to induce degeneration of mammalian male germ cells. The effects on cell-cycle progression, however, have not been thoroughly studied due to lack of methods for identifying effects on a ...
Soués S - - 2001
PURPOSE: The highly schedule-dependent cytotoxic agent etoposide (VP-16) is initially effective in the treatment of small-cell lung cancer (SCLC), particularly in multidrug combination chemotherapy. Heterogeneity in cellular sensitivity to cell cycle arrest may underpin the inadequacy of low-dose extended-cycle single-agent regimes in tumours with partially dysfunctional apoptotic signalling pathways. We ...
Lam C M - - 2001
The dinoflagellate Crypthecodinium cohnii Biecheler propagates by both binary and multiple fission. By a newly developed mutagenesis protocol based on using ethyl methanesulfonate and a cell size screening method, a cell cycle mutant, mf2, was isolated with giant cells which predominantly divide by multiple fission. The average cell size of ...
ModliƄski J A - - 2001
Progress in mammalian cloning started from cloning embryos (of mice, rats, rabbits, sheep, goats, pigs, cattle and rhesus monkeys) and culminated in obtaining clones of sheep, cattle, pigs and mice from adult somatic cells. Knowing the relationship between the cell cycles of the recipient and the donor of cell nucleus ...
Bernander R - - 2001
The early diverging eukaryotic parasite Giardia lamblia is unusual in that it contains two apparently identical nuclei in the vegetative trophozoite stage. We have determined the nuclear and cellular genome ploidy of G. lamblia cells during all stages of the life cycle. During vegetative growth, the nuclei cycle between a ...
Luo Y - - 2001
Chkl is a checkpoint gene that is activated after DNA damage. It phosphorylates and inactivates Cdc25C at the late G2 phase. The inactivation of Cdc25C and consequently, the inactivation of Cdc2, are required for the G2 arrest induced by DNA damage. We treated 184B5 cell line and its E6 transformed ...
Satterwhite D J - - 2000
Transforming growth factor-beta (TGF-beta) protects normal cells from etoposide-induced cell death, yet the mechanism has remained speculative. Studies have shown that etoposide modifies the activity of the topoisomerase IIalpha (topo IIalpha) enzyme, thereby causing DNA damage and inducing cell death. Expression of topo IIalpha is necessary for etoposide-induced cell death, ...
Gilroy D W - - 2001
The purpose of this investigation is to determine whether the levels of cyclooxygenase-2 (COX-2) expression are cell cycle dependent. We used a serum-starved human foreskin fibroblast model to determine changes in COX-2 mRNA, protein, and promoter activity in response to stimulation with interleukin-1b (IL-1b) and phorbol 12-myristate 13-acetate (PMA) at ...
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