scholarly journals Heritable tumor cell division rate heterogeneity induces clonal dominance

2018 ◽  
Vol 14 (2) ◽  
pp. e1005954 ◽  
Author(s):  
Margriet M. Palm ◽  
Marjet Elemans ◽  
Joost B. Beltman
Keyword(s):  
Cell Division ◽  
Tumor Cell ◽  
Rate Heterogeneity ◽  
Division Rate ◽  
Cell Division Rate

scholarly journals Heritable tumor cell division rate heterogeneity induces clonal dominance

2017 ◽  
Author(s):  
Margriet M. Palm ◽  
Marjet Elemans ◽  
Joost B. Beltman
Keyword(s):  
Stem Cells ◽  
Cancer Stem Cells ◽  
Lineage Tracing ◽  
Hierarchical Organization ◽  
Rate Heterogeneity ◽  
Division Rate ◽  
Cell Division Rate ◽  
Mutational Processes ◽  
Selection Of

AbstractTumors consist of a hierarchical population of cells that differ in their phenotype and genotype. This hierarchical organization of cells means that a few clones (i.e., cells and several generations of offspring) are abundant while most are rare, which is called clonal dominance. Such dominance also occurred in published in vitro iterated growth and passage experiments with tumor cells in which genetic barcodes were used for lineage tracing. A potential source for such heterogeneity is that dominant clones derive from cancer stem cells with an unlimited self-renewal capacity. Furthermore, ongoing evolution within the growing population may also induce clonal dominance. To understand how clonal dominance developed in the iterated growth and passage experiments, we built a computational model that accurately simulates these experiments. The model simulations reproduced the clonal dominance that developed in in vitro iterated growth and passage experiments when the division rates vary between cells, due to a combination of initial variation and of ongoing mutational processes. In contrast, the experimental results can neither be reproduced with a model that considers random growth and passage, nor with a model based on cancer stem cells. Altogether, our model suggests that in vitro clonal dominance develops due to selection of fast-dividing clones.

scholarly journals Toxicity at the cellular level of artificial synthetic flavorings

2016 ◽  
Vol 38 (3) ◽  
pp. 297
Author(s):  
Ila Monize Sousa Sales ◽  
Jussara Damascena de Oliveira ◽  
Fabelina Karollyne Silva dos Santos ◽  
Lidiane De Lima Feitoza ◽  
João Marcelo de Castro e Sousa ◽  
...  
Keyword(s):  
Cell Division ◽  
Root Meristem ◽  
Combined Treatment ◽  
Optical Microscope ◽  
Cellular Level ◽  
Combined Treatments ◽  
Division Rate ◽  
Cell Division Rate ◽  
Allium Cepa L ◽  
Genotoxic Action

 The goal of the present study was to evaluate the cytotoxicity and genotoxicity of artificial synthetic flavoring agents cookie and tutti-frutti. To this end, root meristem cells of Allium cepa L. were exposed to these substances in exposure times of 24 and 48 hour using individual doses of 0.3; 0.6 and 0.9 mL and doses combined as follows: 0.3 mL + 0.3 mL; 0.6 mL and 0.9 mL + 0.6 mL + 0.9 mL. After applying the treatments, root meristems were fixed, hydrolyzed, stained and analyzed a total of 5,000 cells using an optical microscope to evaluate each dose and combined treatment. All three doses of cookie flavoring and combined treatments significantly inhibited cell division of the tissue studied. Doses of tutti-frutti caused no change in cell division rate. In addition, doses of both flavorings and treatments combining these solutions induced cell aberrations in a significant number of cells to the A. cepa system. Therefore, under these analytical conditions, cookie flavoring and combined doses were cytotoxic and genotoxic, and tutti-frutti flavoring, although non-cytotoxic, demonstrated genotoxic action. 

scholarly journals Effect of Nitrogen and Periphyton Extract on the Growth of Nostoc sphaericum in Cultures

ISRN Ecology ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-8
Author(s):  
Itzel Becerra-Absalón ◽  
Thomas Buhse ◽  
Carlos Polanco ◽  
Rosaluz Tavera
Keyword(s):  
Cell Division ◽  
Deciduous Forest ◽  
Tropical Deciduous Forest ◽  
Division Rate ◽  
Wetland Ecosystems ◽  
Statistical Verification ◽  
Solid Media ◽  
Cell Division Rate ◽  
Growth Differences ◽  
The Impact

Nostoc sphaericum shows marked growth differences in two Mexican wetland ecosystems consisting of rain forest and tropical deciduous forest, respectively. The amount of nitrogen and periphyton extract dominated by other Cyanoprokaryota had been identified as the most obvious differences between these two ecosystems. We studied the impact of these variables on the physiology and morphology of N. sphaericum. that is, the chlorophyll-a content of the thalli and the changes in the size of the trichomes as well as the cell division rate. Our results combined with a statistical verification indicate that the cell division rate of N. sphaericum with solid media is neither stimulated by nitrogen nor by accompanying cyanoprokaryotes and therefore is assumed to have no impact on the thalli observed in situ. However, these two variables are affecting the size of both the trichomes and the thalli, thus suggested to cause the observed growth differences between the two wetlands.

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