scholarly journals An exactly solvable, spatial model of mutation accumulation in cancer

2016 ◽  
Author(s):  
Chay Paterson ◽  
Martin A. Nowak ◽  
Bartlomiej Waclaw
Keyword(s):  
Cancer Cells ◽  
Three Dimensional ◽  
Spatial Models ◽  
Reproductive Rate ◽  
Driver Mutations ◽  
Net Reproductive Rate ◽  
Migration Rates ◽  
Exactly Solvable ◽  
And Migration ◽  
Average Fitness

One of the hallmarks of cancer is the accumulation of driver mutations which increase the net reproductive rate of cancer cells and allow them to spread. This process has been studied in mathematical models of well mixed populations, and in computer simulations of three-dimensional spatial models. But the computational complexity of these more realistic, spatial models makes it difficult to simulate realistically large and clinically detectable solid tumours. Here we describe an exactly solvable mathematical model of a tumour featuring replication, mutation and local migration of cancer cells. The model predicts a quasi-exponential growth of large tumours even if different fragments of the tumour grow sub-exponentially due to nutrient and space limitations. The model reproduces clinically observed tumour growth times using biologically plausible rates for cell birth, death, and migration rates. We also show that the expected number of accumulated driver mutations increases exponentially in time if the average fitness gain per driver is constant, and that it reaches a plateau if the gains decrease over time. We discuss the realism of the underlying assumptions and possible extensions of the model.

scholarly journals An exactly solvable, spatial model of mutation accumulation in cancer

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Chay Paterson ◽  
Martin A. Nowak ◽  
Bartlomiej Waclaw
Keyword(s):  
Cancer Cells ◽  
Three Dimensional ◽  
Spatial Models ◽  
Reproductive Rate ◽  
Driver Mutations ◽  
Net Reproductive Rate ◽  
Migration Rates ◽  
Exactly Solvable ◽  
And Migration ◽  
Average Fitness

Abstract One of the hallmarks of cancer is the accumulation of driver mutations which increase the net reproductive rate of cancer cells and allow them to spread. This process has been studied in mathematical models of well mixed populations, and in computer simulations of three-dimensional spatial models. But the computational complexity of these more realistic, spatial models makes it difficult to simulate realistically large and clinically detectable solid tumours. Here we describe an exactly solvable mathematical model of a tumour featuring replication, mutation and local migration of cancer cells. The model predicts a quasi-exponential growth of large tumours, even if different fragments of the tumour grow sub-exponentially due to nutrient and space limitations. The model reproduces clinically observed tumour growth times using biologically plausible rates for cell birth, death, and migration rates. We also show that the expected number of accumulated driver mutations increases exponentially in time if the average fitness gain per driver is constant, and that it reaches a plateau if the gains decrease over time. We discuss the realism of the underlying assumptions and possible extensions of the model.

scholarly journals Rapid, but limited, zooplankton adaptation to simultaneous warming and acidification

2021 ◽  
Author(s):  
Hans G. Dam ◽  
James A deMayo ◽  
Gihong Park ◽  
Lydia Norton ◽  
Xuejia He ◽  
...  
Keyword(s):  
Climate Change ◽  
Egg Production ◽  
Life History Traits ◽  
Reproductive Rate ◽  
Rapid Adaptation ◽  
Net Reproductive Rate ◽  
Marine Copepod ◽  
Evolutionary Rescue ◽  
Acidic Conditions ◽  
Average Fitness

Predicting the response of marine metazoans to climate change is hampered by a lack of studies on evolutionary adaptation, particularly to combined warming and acidification. To test whether the ubiquitous marine copepod Acartia tonsa can adapt to warmer and acidified conditions, we tracked five fitness-relevant life-history traits for 25 generations (~ 1 year) with a 2 x 2 factorial design of temperature (18 C, 22 C) and pCO2 (400, 2000 μatm). Initially, combined warm, acidic conditions decreased egg production and hatching frequency, resulting in a 56% reduction in population fitness (net reproductive rate). However, both traits recovered after three generations and average fitness was reduced by only 9% thereafter, indicating rapid adaptation. Antagonistic interactions between warming and acidification in later generations decreased survival, thereby limiting full evolutionary rescue. Our results suggest that interactions between warming and acidification constrain evolutionary rescue and add complexity to predictions of metazoan populations responses to climate change.

scholarly journals Dual phenotype of MDA-MB-468 cancer cells reveals mutual regulation of tensin3 and adhesion plasticity

2017 ◽  
Author(s):  
Astrid Veβ ◽  
Ulrich Blache ◽  
Laura Leitner ◽  
Angela R.M. Kurz ◽  
Anja Ehrenpfordt ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Focal Adhesion ◽  
Three Dimensional ◽  
Suspension Cells ◽  
Adhesion Protein ◽  
Cell Matrix ◽  
Mutual Regulation ◽  
Summary Statement ◽  
And Migration ◽  
Focal Adhesion Protein

AbstractPlasticity between adhesive and less-adhesive states is important for mammalian cell behaviour. To investigate adhesion plasticity, we have selected a stable isogenic subpopulation of MDA-MB-468 breast carcinoma cells which grows in suspension. These suspension cells are unable to re-adhere to various matrices or to contract three-dimensional collagen lattices. By transcriptome analysis, we identified the focal adhesion protein tensin3 (Tns3) as a determinant of adhesion plasticity. Tns3 is strongly reduced on mRNA and protein level in suspension cells. Furthermore, challenging breast cancer cells transiently with non-adherent conditions markedly reduces Tns3 expression, which is regained upon re-adhesion. Stable knockdown of Tns3 in parental cells results in defective adhesion, spreading and migration. Tns3 knockdown cells display impaired structure and dynamics of focal adhesion complexes as determined by immunostaining. Restoration of Tns3 expression in suspension cells partially rescues adhesion and focal contact composition. Our work identifies Tns3 as a critical focal adhesion component regulated by, and functionally contributing to, the switch between adhesive and non-adhesive states in MDA-MB-468 cancer cells.Summary statementWe identify the cell-matrix adapter protein tensin3 as a determinant of adhesion plasticity, using cancer cells selected for non-adherent growth. Tensin3 expression constitutes a feedback loop controlling adhesion and motility.

scholarly journals The mechanics and dynamics of cancer cells sensing noisy 3D contact guidance

2021 ◽  
Vol 118 (10) ◽  
pp. e2024780118
Author(s):  
Jihan Kim ◽  
Yuansheng Cao ◽  
Christopher Eddy ◽  
Youyuan Deng ◽  
Herbert Levine ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Cell Morphology ◽  
Principal Direction ◽  
Three Dimensional ◽  
Contact Guidance ◽  
Directional Bias ◽  
Cell Responses ◽  
Migration Dynamics ◽  
3D Collagen ◽  
And Migration

Contact guidance is a major physical cue that modulates cancer cell morphology and motility, and is directly linked to the prognosis of cancer patients. Under physiological conditions, particularly in the three-dimensional (3D) extracellular matrix (ECM), the disordered assembly of fibers presents a complex directional bias to the cells. It is unclear how cancer cells respond to these noncoherent contact guidance cues. Here we combine quantitative experiments, theoretical analysis, and computational modeling to study the morphological and migrational responses of breast cancer cells to 3D collagen ECM with varying degrees of fiber alignment. We quantify the strength of contact guidance using directional coherence of ECM fibers, and find that stronger contact guidance causes cells to polarize more strongly along the principal direction of the fibers. Interestingly, sensitivity to contact guidance is positively correlated with cell aspect ratio, with elongated cells responding more strongly to ECM alignment than rounded cells. Both experiments and simulations show that cell–ECM adhesions and actomyosin contractility modulate cell responses to contact guidance by inducing a population shift between rounded and elongated cells. We also find that cells rapidly change their morphology when navigating the ECM, and that ECM fiber coherence modulates cell transition rates between different morphological phenotypes. Taken together, we find that subcellular processes that integrate conflicting mechanical cues determine cell morphology, which predicts the polarization and migration dynamics of cancer cells in 3D ECM.

Effects and Mechanisms of Anlotinib and Dihydroartemisinin Combination Therapy in Ameliorating Malignant Biological Behavior of Gastric Cancer Cells

2020 ◽  
Vol 21 ◽  
Author(s):  
Qiong Luo ◽  
Suyun Zhang ◽  
Donghuan Zhang ◽  
Rui Feng ◽  
Nan Li ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cancer Cells ◽  
Molecular Mechanisms ◽  
Chorioallantoic Membrane ◽  
Cell Counting ◽  
Biological Behavior ◽  
Gastric Cancer Cells ◽  
Invasion And Migration ◽  
Apoptosis Related Protein ◽  
And Migration

Background: Gastric cancer(GC) is currently one of the major malignancies that threatens human lives and health. Anlotinib is a novel small-molecule that inhibits angiogenesis to exert anti-tumor effects. However, the function in gastric cancer is incompletely understood. Objective: The aim of the present study was to investigate the anti-tumor effects and molecular mechanisms of anlotinib combined with dihydroartemisinin (DHA) in SGC7901 gastric cancer cells. Method: Different concentrations of anlotinib and DHA were used to treat SGC7901 gastric cancer cells, after which cell proliferation was measured. Drug interactions of anlotinib and DHA were analyzed by the Chou-Talalay method with CompuSyn software. proliferation, apoptosis, invasion, migration, and angiogenesis were measured using the cell counting kit-8 (CCK8) assay, flow cytometry, Transwell invasion assays, scratch assays, and chicken chorioallantoic membrane (CAM) assays. proliferation-associated protein (Ki67), apoptosis-related protein (Bcl-2), and vascular endothelial growth factor A (VEGF-A) were quantified by Western bloting. Results: The combination of 2.5 μmol/L of anlotinib and 5 of μmol/L DHA was highly synergistic in inhibiting cell growth, significantly increased the apoptosis rate and suppressed obviously the invasion and migration capability and angiogenesis of gastric cancer cells. In addition, the expression levels of Ki67, Bcl-2, and VEGF-A, as well as angiogenesis, were significantly decreased in the Combination of drugs compared with in control and either drug alone. Conclusion: The combination of anlotinib and DHA showed synergistic antitumor activity, suggesting their potential in treating patients with gastric cancer.

scholarly journals Comparative demography of the exotic Harmonia axyridis with other aphidophagous coccinellids reared on artificial diet

2014 ◽  
Vol 49 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Julianne Milléo ◽  
Francisco Sales Fernandes ◽  
Wesley Augusto Conde Godoy
Keyword(s):  
Life Table ◽  
Harmonia Axyridis ◽  
Reproductive Rate ◽  
The Other ◽  
Adult Longevity ◽  
Net Reproductive Rate ◽  
Anagasta Kuehniella ◽  
Survival Percentage ◽  
Comparative Demography ◽  
Biological Aspects

The objective of this work was to compare biological aspects and life table parameters of the coccinellids Harmonia axyridis, Cycloneda sanguineaand Hippodamia convergens. Insects were fed eggs of Anagasta kuehniella, and reared at 24.5±1ºC, 70±10% relative humidity, with a 12 hour photophase. Hippodamia convergenstook about 1.6 day to complete development, longer than H. axyridis, and 2.4 day longer than C. sanguinea.At immature stages, H. axyridisexhibited the highest survival percentage (49.2%), in comparison to the other coccinellids. For mean adult longevity, H. convergenswas deficient, in comparison with the other species. Mean period of pre oviposition was the longest in C. sanguinea; the longest oviposition time occurred for H. axyridis; and the post oviposition period was similar between the coccinellids. Considering the reproductive parameters, H. axyridisshowed the best performance in all aspects. For life table, the values of H. convergenswere higher than, although close, to those of H. axyridis. Nevertheless, the high net reproductive rate of H. axyridis showed this species potential to increase population size. The biological characteristics of the exotic H. axyridis favors its invasion and establishment in Brazil, corroborating results noticed in other countries.

scholarly journals CXCL2-CXCR2 axis mediates αV integrin-dependent peritoneal metastasis of colon cancer cells

2021 ◽  
Author(s):  
Mattias Lepsenyi ◽  
Nader Algethami ◽  
Amr A. Al-Haidari ◽  
Anwar Algaber ◽  
Ingvar Syk ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Cell Adhesion ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Colon Cancer Cell ◽  
Colon Cancer Cells ◽  
Cancer Cell Adhesion ◽  
And Migration ◽  
Cxcr2 Antagonist

AbstractPeritoneal metastasis is an insidious aspect of colorectal cancer. The aim of the present study was to define mechanisms regulating colon cancer cell adhesion and spread to peritoneal wounds after abdominal surgery. Mice was laparotomized and injected intraperitoneally with CT-26 colon carcinoma cells and metastatic noduli in the peritoneal cavity was quantified after treatment with a CXCR2 antagonist or integrin-αV-antibody. CT-26 cells expressed cell surface chemokine receptors CXCR2, CXCR3, CXCR4 and CXCR5. Stimulation with the CXCR2 ligand, CXCL2, dose-dependently increased proliferation and migration of CT-26 cells in vitro. The CXCR2 antagonist, SB225002, dose-dependently decreased CXCL2-induced proliferation and migration of colon cancer cells in vitro. Intraperitoneal administration of CT-26 colon cancer cells resulted in wide-spread growth of metastatic nodules at the peritoneal surface of laparotomized animals. Laparotomy increased gene expression of CXCL2 at the incisional line. Pretreatment with CXCR2 antagonist reduced metastatic nodules by 70%. Moreover, stimulation with CXCL2 increased CT-26 cell adhesion to extracellular matrix (ECM) proteins in a CXCR2-dependent manner. CT-26 cells expressed the αV, β1 and β3 integrin subunits and immunoneutralization of αV abolished CXCL2-triggered adhesion of CT-26 to vitronectin, fibronectin and fibrinogen. Finally, inhibition of the αV integrin significantly attenuated the number of carcinomatosis nodules by 69% in laparotomized mice. These results were validated by use of the human colon cancer cell line HT-29 in vitro. Our data show that colon cancer cell adhesion and growth on peritoneal wound sites is mediated by a CXCL2-CXCR2 signaling axis and αV integrin-dependent adhesion to ECM proteins.

Spreading and Migration of Nasopharyngeal Normal and Cancer Cells on Microgratings

2021 ◽  
Vol 4 (4) ◽  
pp. 3224-3231
Author(s):  
Yi Liu ◽  
Jifeng Ren ◽  
Ruolin Zhang ◽  
Shuhuan Hu ◽  
Stella W. Pang ◽  
...  
Keyword(s):  
Cancer Cells ◽  
And Migration

scholarly journals Controllable Drug Delivery by Na+/K+ ATPase α1 Targeting Peptide Conjugated DSPE-PEG Nanocarriers for Breast Cancer

2021 ◽  
Vol 20 ◽  
pp. 153303382110278
Author(s):  
Yayan Yang ◽  
Qian Feng ◽  
Chuanfeng Ding ◽  
Wei Kang ◽  
Xiufeng Xiao ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Drug Delivery ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Click Reaction ◽  
Chemotherapy Drugs ◽  
Targeting Peptide ◽  
And Migration

Although Epirubicin (EPI) is a commonly used anthracycline for the treatment of breast cancer in clinic, the serious side effects limit its long-term administration including myelosuppression and cardiomyopathy. Nanomedicines have been widely utilized as drug delivery vehicles to achieve precise targeting of breast cancer cells. Herein, we prepared a DSPE-PEG nanocarrier conjugated a peptide, which targeted the breast cancer overexpression protein Na+/K+ ATPase α1 (NKA-α1). The nanocarrier encapsulated the EPI and grafted with the NKA-α1 targeting peptide through the click reaction between maleimide and thiol groups. The EPI was slowly released from the nanocarrier after entering the breast cancer cells with the guidance of the targeting NKA-α1 peptide. The precise and controllable delivery and release of the EPI into the breast cancer cells dramatically inhibited the cells proliferation and migration in vitro and suppressed the tumor volume in vivo. These results demonstrate significant prospects for this nanocarrier as a promising platform for numerous chemotherapy drugs.

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