Planning Blocked Mitosis Experiments for Efficient Estimation of Population-Doubling Time and Cell-Cycle Time

Biometrics ◽  
1982 ◽  
Vol 38 (3) ◽  
pp. 777 ◽  
Author(s):  
Robert G. Staudte
Keyword(s):  
Cell Cycle ◽  
Cycle Time ◽  
Doubling Time ◽  
Efficient Estimation ◽  
Population Doubling ◽  
Population Doubling Time ◽  
Cell Cycle Time

scholarly journals Transcript profile distinguishes variability in human myogenic progenitor cell expansion capacity

2018 ◽  
Vol 50 (10) ◽  
pp. 817-827 ◽  
Author(s):  
Emily S. Riddle ◽  
Erica L. Bender ◽  
Anna E. Thalacker-Mercer
Keyword(s):  
Cell Cycle ◽  
Doubling Time ◽  
Growth Parameters ◽  
Principal Component ◽  
Saturation Density ◽  
Population Doubling ◽  
Population Doubling Time ◽  
Transcript Profile ◽  
Q Value ◽  
Expansion Capacity

Primary human muscle progenitor cells (hMPCs) are commonly used to understand skeletal muscle biology, including the regenerative process. Variability from unknown origin in hMPC expansion capacity occurs independently of disease, age, or sex of the donor. We sought to determine the transcript profile that distinguishes hMPC cultures with greater expansion capacity and to identify biological underpinnings of these transcriptome profile differences. Sorted (CD56+/CD29+) hMPC cultures were clustered by unbiased, K-means cluster analysis into FAST and SLOW based on growth parameters (saturation density and population doubling time). FAST had greater expansion capacity indicated by significantly reduced population doubling time (−60%) and greater saturation density (+200%), nuclei area under the curve (AUC, +250%), and confluence AUC (+120%). Additionally, FAST had fewer % dead cells AUC (−44%, P < 0.05). RNA sequencing was conducted on RNA extracted during the expansion phase. Principal component analysis distinguished FAST and SLOW based on the transcript profiles. There were 2,205 differentially expressed genes (DEgenes) between FAST and SLOW (q value ≤ 0.05); 362 DEgenes met a more stringent cut-off (q value ≤ 0.001 and 2.0 fold-change). DEgene enrichment suggested FAST (vs. SLOW) had promotion of the cell cycle, reduced apoptosis and cellular senescence, and enhanced DNA replication. Novel (RABL6, IRGM1, and AREG) and known (FOXM1, CDKN1A, Rb) genes emerged as regulators of identified functional pathways. Collectively the data suggest that variation in hMPC expansion capacity occurs independently of age and sex and is driven, in part, by intrinsic mechanisms that support the cell cycle.

scholarly journals Molecular Aspects of Adipose-Derived Stromal Cell Senescence in a Long-Term Culture: A Potential Role of Inflammatory Pathways

2020 ◽  
Vol 29 ◽  
pp. 096368972091734 ◽  
Author(s):  
Marta Pokrywczynska ◽  
Małgorzata Maj ◽  
Tomasz Kloskowski ◽  
Monika Buhl ◽  
Daria Balcerczyk ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Doubling Time ◽  
Population Doubling ◽  
Population Doubling Time ◽  
Proliferative Potential ◽  
Differentiation Potential ◽  
Long Term Culture ◽  
Stromal Stem Cells

Long-term culture of mesenchymal stromal/stem cells in vitro leads to their senescence. It is very important to define the maximal passage to which the mesenchymal stromal/stem cells maintain their regenerative properties and can be used for cellular therapies and construction of neo-organs for clinical application. Adipose-derived stromal/stem cells were isolated from porcine adipose tissue. Immunophenotype, population doubling time, viability using bromodeoxyuridine assay, MTT assay, clonogencity, β-galactosidase activity, specific senescence-associated gene expression, apoptosis, and cell cycle of adipose-derived mesenchymal stromal/stem cells (AD-MSCs) were analyzed. All analyses were performed through 12 passages (P). Decreasing viability and proliferative potential of AD-MSCs with subsequent passages together with prolonged population doubling time were observed. Expression of β-galactosidase gradually increased after P6. Differentiation potential of AD-MSCs into adipogenic, chondrogenic, and osteogenic lineages decreased at the end of culture (P10). No changes in the cell cycle, the number of apoptotic cells and expression of specific AD-MSC markers during the long-term culture were revealed. Molecular analysis showed increased expression of genes involved in activation of inflammatory response. AD-MSCs can be cultured for in vivo applications without loss of their properties up to P6.

scholarly journals Scaling of G1 duration with population doubling time by a cyclin inSaccharomyces cerevisiae

2017 ◽  
Author(s):  
Heidi M. Blank ◽  
Michelle Callahan ◽  
Ioannis P.E. Pistikopoulos ◽  
Aggeliki O. Polymenis ◽  
Michael Polymenis
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Translational Control ◽  
Doubling Time ◽  
Qualitative Description ◽  
Quantitative Relation ◽  
Population Doubling ◽  
Population Doubling Time ◽  
Specific Cell ◽  
Cell Cycle Phases

ABSTRACTThe longer cells stay in particular phases of the cell cycle, the longer it will take these cell populations to increase. However, the above qualitative description has very little predictive value, unless it can be codified mathematically. A quantitative relation that defines the population doubling time (Td) as a function of the time eukaryotic cells spend in specific cell cycle phases would be instrumental for estimating rates of cell proliferation and for evaluating introduced perturbations. Here, we show that in human cells the length of the G1 phase (TG1) regressed on Tdwith a slope of ≈0.75, while in the yeastSaccharomyces cerevisiaethe slope was slightly smaller, at ≈0.60. On the other hand, cell size was not strongly associated with Tdor TG1in cell cultures that were proliferating at different rates. Furthermore, we show that levels of the yeast G1 cyclin Cln3p were positively associated with rates of cell proliferation over a broad range, at least in part through translational control mediated by a short uORF in theCLN3transcript. Cln3p was also necessary for the proper scaling between TG1and Td. In contrast, yeast lacking the Whi5p transcriptional repressor maintained the scaling between TG1and Td. These data reveal fundamental scaling relations between the duration of eukaryotic cell cycle phases and rates of cell proliferation, point to the necessary role of Cln3p in these relations in yeast and provide a mechanistic basis linking Cln3p levels to proliferation rates and the scaling of G1 with doubling time.

Review of basic concepts of cell kinetics as applied to brain tumors

1975 ◽  
Vol 42 (2) ◽  
pp. 123-131 ◽  
Author(s):  
Takao Hoshino ◽  
Charles B. Wilson
Keyword(s):  
Cell Cycle ◽  
Brain Tumors ◽  
Cycle Time ◽  
Doubling Time ◽  
Cell Kinetics ◽  
Cell Loss ◽  
Growth Fraction ◽  
Cell Cycle Time ◽  
Tumor Doubling Time ◽  
Basic Concepts

✓ The authors review and discuss the basic concepts of cell kinetics as applied to brain tumors. Uncontrolled growth of a neoplasm represents an expanding tumor cell population. Four growth parameters characterize the behavior of a neoplastic population: cell cycle time, growth fraction, tumor doubling time, and cell loss. The concept of provisionally nondividing cells explains the disparity between cell cycle time and tumor doubling time. Human gliomas, like many non-neural solid tumors, contain variable proportions of actively proliferating and nonproliferating tumor cells; this ratio is expressed by the growth fraction. The major kinetic difference between glioblastomas and differentiated astrocytomas resides in their respective growth fractions, in all likelihood an inherent biological characteristic of each tumor. Glioblastoma proliferates at a rapid rate, and only a high rate of cell loss prevents this tumor from doubling its volume in less than 1 week. The selection of drugs and design of drug schedules for treatment of glioblastomas should be made with the knowledge that 60% to 70% of the cells in this tumor are resting (nonproliferating). If experience with other solid tumors is any guide, judicious selection and combined use of drugs according to kinetically sound schedules will produce more effective chemotherapy of brain tumors.

Cytokinetic Analysis at Various Ages of an Ascites Tumor after Radiation

1978 ◽  
Vol 64 (5) ◽  
pp. 463-470
Author(s):  
Eva Siracká ◽  
Natasa Pappová
Keyword(s):  
Cell Cycle ◽  
Growth Rate ◽  
Cycle Time ◽  
Doubling Time ◽  
Cell Loss ◽  
Whole Body ◽  
Ascites Tumor ◽  
Cell Cycle Time ◽  
Slowing Down ◽  
Proliferative Phase

A cytokinetic analysis has been made of 5-day and of 10-day old murine 6C3HED ascites lymphosarcoma (Gardner) by using a growth curve, percentage of labeled mitoses curves, and continuous labeling curves. The doubling time increased from 36 h in the proliferative phase of growth to 252 h in the stationary phase. The slowing down of the growth rate was due to prolongation of the cell cycle time, with greatest extension in G1 and increased cell loss. The measurement of the kinetic parameters made immediately after irradiation with a whole-body single dose of 3 Gy (300 rad) showed an increase in duration of the cell cycle in the 5-day-old tumor, while in the 10-day-old tumor the cell cycle time was decreased due to reduce length in the G1 phase.

scholarly journals Unequal division in Saccharomyces cerevisiae and its implications for the control of cell division.

1977 ◽  
Vol 75 (2) ◽  
pp. 422-435 ◽  
Author(s):  
L H Hartwell ◽  
M W Unger
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Doubling Time ◽  
Daughter Cell ◽  
Population Doubling ◽  
Population Doubling Time ◽  
Protein Synthesis Inhibitor ◽  
Parent Cell ◽  
Rate Limiting ◽  
Mating Factor

The budding yeast, Saccharomyces cerevisiae, was grown exponentially at different rates in the presence of growth rate-limiting concentrations of a protein synthesis inhibitor, cycloheximide. The volumes of the parent cell and the bud were determined as were the intervals of the cell cycle devoted to the unbudded and budded periods. We found that S. cerevisiae cells divide unequally. The daughter cell (the cell produced at division by the bud of the previous cycle) is smaller and has a longer subsequent cell cycle than the parent cell which produced it. During the budded period most of the volume increase occurs in the bud and very little in the parent cell, while during the unbudded period both the daughter and the parent cell increase significantly in volume. The length of the budded interval of the cell cycle varies little as a function of population doubling time; the unbudded interval of the parent cell varies moderately; and the unbudded interval for the daughter cell varies greatly (in the latter case an increase of 100 min in population doubling time results in an increase of 124 min in the daughter cell's unbudded interval). All of the increase in the unbudded period occurs in that interval of G1 that precedes the point of cell cycle arrest by the S. cerevisiae alpha-mating factor. These results are qualitatively consistent with and support the model for the coordination of growth and division (Johnston, G. C., J. R. Pringle, and L. H. Hartwell. 1977. Exp. Cell. Res. 105:79-98.) This model states that growth and not the events of the DNA division cycle are rate limiting for cellular proliferation and that the attainment of a critical cell size is a necessary prerequisite for the "start" event in the DNA-division cycle, the event that requires the cdc 28 gene product, is inhibited by mating factor and results in duplication of the spindle pole body.

Estimation of growth fraction with bromodeoxyuridine in human central nervous system tumors

1986 ◽  
Vol 65 (5) ◽  
pp. 659-663 ◽  
Author(s):  
Yoshihiko Yoshii ◽  
Yutaka Maki ◽  
Koji Tsuboi ◽  
Yuji Tomono ◽  
Kunio Nakagawa ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cycle Time ◽  
Doubling Time ◽  
Malignant Gliomas ◽  
Cell Loss ◽  
Growth Fraction ◽  
Cell Cycle Time ◽  
Tumor Doubling Time ◽  
Content Type ◽  
Fine Print

✓ Twenty-five patients with tumors of the central nervous system received bromodeoxyuridine (BUdR), 200 mg/sq m, by intravenous infusion every 8 hours for 3 days before surgery. Excised tumor specimens were fixed in chilled 70% ethanol, embedded in paraffin, and cut into 6-µm sections. Each section was reacted with monoclonal antibodies against BUdR and stained with immunoperoxidase to identify nuclei that had incorporated BUdR. The growth fraction of each tumor was estimated by calculating the ratio of BUdR-positive nuclei to the total number of tumor cells in three to six microscopic fields in viable areas of the tumor. In seven cases, the tumor doubling time was measured from the serial computerized tomography scans and an attempt was made to estimate the cell cycle time. The growth fractions ranged from 9.1% to 46.5% in malignant gliomas, 2.0% to 6.7% in low-grade gliomas, 11.2% to 43.2% in metastatic brain tumors, 0.8% to 1.9% in pituitary adenomas, 3.9% to 4.6% in acoustic neurinomas, and 6.2% to 8.2% in meningiomas and cerebellar hemangioblastomas. The estimated cell cycle time was 5 to 12 days in most malignant gliomas and brain metastases; however, the actual cell cycle time should be substantially shorter because cell loss was not considered in the calculation. Although the growth fraction appeared to correlate with the biological malignancy of each tumor, the tumor doubling time did not reflect growth potential. It is possible that unpredictable cell loss plays an important role in tumor growth at certain sizes. Therefore, the cell cycle times calculated in this study are considerably overestimated and should be interpreted with caution.

Nuclear DNA content and minimum generation time in herbaceous plants

1972 ◽  
Vol 181 (1063) ◽  
pp. 109-135 ◽  
Keyword(s):  
Cell Cycle ◽  
Dna Content ◽  
Cycle Time ◽  
Generation Time ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Annual Species ◽  
Cell Cycle Time ◽  
Developmental Processes ◽  
The Mean

Many components of cell and nuclear size and mass are correlated with nuclear DNA content in plants, as also are the durations and rates of such developmental processes as mitosis and meiosis. It is suggested that the multiple effects of the mass of nuclear DNA which affect all cells and apply throughout the life of the plant can together determine the minimum generation time for each species. The durations of mitosis and of meiosis are both positively correlated with nuclear DNA content and, therefore, species with a short minimum generation time might be expected to have a shorter mean cell cycle time and mean meiotic duration, and a lower mean nuclear DNA content, than species with a long mean minimum generation time. In tests of this hypothesis, using data collated from the literature, it is shown that the mean cell cycle time and the mean meiotic duration in annual species is significantly shorter than in perennial species. Furthermore, the mean nuclear DNA content of annual species is significantly lower than for perennial species both in dicotyledons and monocotyledons. Ephemeral species have a significantly lower mean nuclear DNA content than annual species. Among perennial monocotyledons the mean nuclear DNA content of species which can complete a life cycle within one year (facultative perennials) is significantly lower than the mean nuclear DNA content of those which cannot (obligate perennials). However, the mean nuclear DNA content of facultative perennials does not differ significantly from the mean for annual species. It is suggested that the effects of nuclear DNA content on the duration of developmental processes are most obvious during its determinant stages, and that the largest effects of nuclear DNA mass are expressed at times when development is slowest, for instance, during meiosis or at low temperature. It has been suggested that DNA influences development in two ways, directly through its informational content, and indirectly by the physical-mechanical effects of its mass. The term 'nucleotype' is used to describe those conditions of the nucleus which effect the phenotype independently of the informational content of the DNA. It is suggested that cell cycle time, meiotic duration, and minimum generation time are determined by the nucleotype. In addition, it may be that satellite DNA is significant in its nucleotypic effects on developmental processes.

Sign in / Sign up

Export Citation Format

Share Document