scholarly journals Gap Junctions Amplify Spatial Variations in Cell Volume in Proliferating Solid Tumors

2020 ◽  
Author(s):  
Eoin McEvoy ◽  
Yulong Han ◽  
Ming Guo ◽  
Vivek B. Shenoy

AbstractCancer progression is driven by cell proliferation, apoptosis, and matrix invasion, which in turn depend on a myriad of factors including microenvironment stiffness, nutrient supply, and intercellular communication. Cell proliferation is regulated by volume, but in 3D clusters it remains unclear how multiple cells interact to control their size. In this study, we propose a mechano-osmotic model to investigate the evolution of volume dynamics within multicellular systems. Volume control depends on an interplay between multiple cellular constituents, including gap junctions, mechanosensitive ion channels, energy consuming ion transporters, and the actomyosin cortex, that coordinate to manipulate cellular osmolarity. In connected cells, mechanical loading is shown to significantly affect how these components cooperate to transport ions, and precise volume control is impacted by the emergence of osmotic pressure gradients between cells. Consequent increases in cellular ion concentrations drive swelling, while a loss of ions impedes the compression resistance of cells. Combining the modeling framework with novel experiments, we identify how gap junctions can amplify spatial variations in cell volume within multicellular spheroids and, further, describe how the process depends on proliferation-induced solid stress. Our model provides new insight into the role of gap junctions in cancer progression and can help guide the development of therapeutics that target inter- and extra-cellular ion transport.

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Eoin McEvoy ◽  
Yu Long Han ◽  
Ming Guo ◽  
Vivek B. Shenoy

AbstractSustained proliferation is a significant driver of cancer progression. Cell-cycle advancement is coupled with cell size, but it remains unclear how multiple cells interact to control their volume in 3D clusters. In this study, we propose a mechano-osmotic model to investigate the evolution of volume dynamics within multicellular systems. Volume control depends on an interplay between multiple cellular constituents, including gap junctions, mechanosensitive ion channels, energy-consuming ion pumps, and the actomyosin cortex, that coordinate to manipulate cellular osmolarity. In connected cells, we show that mechanical loading leads to the emergence of osmotic pressure gradients between cells with consequent increases in cellular ion concentrations driving swelling. We identify how gap junctions can amplify spatial variations in cell volume within multicellular spheroids and, further, describe how the process depends on proliferation-induced solid stress. Our model may provide new insight into the role of gap junctions in breast cancer progression.


2020 ◽  
Vol 85 ◽  
pp. 131-139
Author(s):  
S Shen ◽  
Y Shimizu

Despite the importance of bacterial cell volume in microbial ecology in aquatic environments, literature regarding the effects of seasonal and spatial variations on bacterial cell volume remains scarce. We used transmission electron microscopy to examine seasonal and spatial variations in bacterial cell size for 18 mo in 2 layers (epilimnion 0.5 m and hypolimnion 60 m) of Lake Biwa, Japan, a large and deep freshwater lake. During the stratified period, we found that the bacterial cell volume in the hypolimnion ranged from 0.017 to 0.12 µm3 (median), whereas that in the epilimnion was less variable (0.016 to 0.033 µm3, median) and much lower than that in the hypolimnion. Additionally, in the hypolimnion, cell volume during the stratified period was greater than that during the mixing period (up to 5.7-fold). These differences in cell volume resulted in comparable bacterial biomass in the hypolimnion and epilimnion, despite the fact that there was lower bacterial abundance in the hypolimnion than in the epilimnion. We also found that the biomass of larger bacteria, which are not likely to be grazed by heterotrophic nanoflagellates, increased in the hypolimnion during the stratified period. Our data suggest that estimation of carbon flux (e.g. bacterial productivity) needs to be interpreted cautiously when cell volume is used as a constant parametric value. In deep freshwater lakes, a difference in cell volume with seasonal and spatial variation may largely affect estimations.


Author(s):  
Islam Mohamed ◽  
Ahmed Moahmed ◽  
Mennatallah Abdelkader ◽  
Alaaeldin Saleh ◽  
Ala-Eddin Al-Moustafa

Introduction: Elaeagnus angustifolia (EA) is a medicinal plant that has been used for centuries in treating many human diseases, in the Middle East, including fever, amoebic dysentery, gastrointestinal problems. However, the effect of EA plant extract on human cancer progression especially oral malignancy has not been investigated yet. Thus, first we examined the effect of EA flower extract on angiogenesis in ovo, and on selected parameters in human oral cancer cells. Materials and methods: Chorioallantoic membranes (CAMs) of chicken embryos at 3-7 days of incubation were used to assess the effect EAflower plant extract on angiogenesis. Meanwhile, cell proliferation, soft agar, cell cycle, cell invasion and cell wounding assays were performed to explore the outcome of EA plant extract on FaDu and SCC25 oral cancer cell lines. On the other hand, western blot analysis was carried out to evaluate E-cadherin and Erk1/Erk2 expression and activation, respectively, in FaDu and SCC25 under the effect of EA extract. Results: Our data show that EA extract inhibits cell proliferation and colony formation, in addition to the initiation of Scell cycle arrest and reductionof G1/G2 phases. In parallel, EA extract provokes differentiation to an epithelial phenotype “mesenchymal-epithelial transition: MET” which is the opposite of “epithelial-mesenchymal transition, EMT”: an important event in cell invasion and metastasis. Thus, EA extract causes a dramatic decrease in cell motility and invasion abilities of FaDu and SCC25 cancer cells in comparison with their controls. These changes are accompanied by an up-regulation of E-cadherin expression. The molecular pathway analysis of the EA flower extract reveals that it can inhibit the phosphorylation of Erk1/Erk2, which could be behind the inhibition of angiogenesis, the initiation of MET event and the overexpression of E-cadherin. Conclusions: Our findings indicate that EA plant extract can downgrade human oral cancer progression by the inhibition of angiogenesis and cell invasion via Erk1/Erk2 signaling pathways.


2006 ◽  
Vol 13 (5) ◽  
pp. 191-193
Author(s):  
V. Sangwan ◽  
M. Park

Tight control of cell proliferation and morphogenesis in conjunction with programmed cell death (apoptosis) is required to ensure normal tissue patterning. [...]


BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Caihong Wen ◽  
Xiaoqing Feng ◽  
Honggang Yuan ◽  
Yong Gong ◽  
Guangsheng Wang

Abstract Background Circular RNAs (circRNAs) feature prominently in tumor progression. However, the biological function and molecular mechanism of circ_0003266 in colorectal cancer (CRC) require further investigation. Methods Circ_0003266 expression in 46 pairs CRC tissues / adjacent tissues, and CRC cell lines was detected by quantitative real-time polymerase chain reaction (qRT-PCR); after circ_0003266 was overexpressed or knocked down in CRC cells, cell proliferation, apoptosis, migration, and invasion were evaluated by the cell counting kit-8 (CCK-8), flow cytometry, and Transwell assays, respectively; the interaction among circ_0003266, miR-503-5p, and programmed cell death 4 (PDCD4) was confirmed using bioinformatics analysis and dual-luciferase reporter assay; PDCD4 protein expression in CRC cells was quantified using Western blot. Results Circ_0003266 was significantly lowly expressed in CRC tissues and cell lines. Circ_0003266 overexpression markedly repressed CRC cell proliferation, migration, and invasion, and accelerated the cell apoptosis, but its overexpression promoted the malignant phenotypes of CRC cells. PDCD4 was a direct target of miR-503-5p and circ_0003266 promoted PDCD4 expression by competitively sponging miR-503-5p. Conclusion Circ_0003266 suppresses the CRC progression via sponging miR-503-5p and regulating PDCD4 expressions, which suggests that circ_0003266 may serve as a novel target for the treatment of CRC.


Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 860
Author(s):  
Chia-Herng Yue ◽  
Muhammet Oner ◽  
Chih-Yuan Chiu ◽  
Mei-Chih Chen ◽  
Chieh-Lin Teng ◽  
...  

Medullary thyroid cancer (MTC) is a neuroendocrine tumor that arises from the parafollicular C-cells, which produces the hormone calcitonin. RET is a transmembrane receptor protein-tyrosine kinase, which is highly expressed in MTC. Our previous studies reported that cyclin-dependent kinase 5 (CDK5) plays a crucial role in cancer progression, including MTC. However, the role of CDK5 in GDNF-induced RET signaling in medullary thyroid cancer proliferation remains unknown. Here, we investigated RET activation and its biochemically interaction with CDK5 in GDNF-induced medullary thyroid cancer proliferation. Our results demonstrated that GDNF stimulated RET phosphorylation and thus subsequently resulted in CDK5 activation by its phosphorylation. Activated CDK5 further caused STAT3 activation by its specific phosphorylation at Ser727. Moreover, we also found that GDNF treatment enhanced ERK1/2 and EGR1 activity, which is involved in p35 activation. Interestingly, we identified for the first time that CDK5 physically interacted with RET protein in MTC. Overall, our results provide a new mechanism for medullary thyroid cancer cell proliferation, suggesting that targeting CDK5 may be a promising therapeutic candidate for human medullary thyroid cancer in the near future.


2014 ◽  
Vol 42 (5) ◽  
pp. 1372-1377 ◽  
Author(s):  
Emily L. Ruban ◽  
Riccardo Ferro ◽  
Syamsul Ahmad Arifin ◽  
Marco Falasca

Lysophosphatidylinositol (LPI) is a well-known bioactive lipid that is able to activate signalling cascades relevant to cell proliferation, migration, survival and tumorigenesis. Our previous work suggested that LPI is involved in cancer progression since it can be released in the medium of Ras-transformed fibroblasts and can function as an autocrine modulator of cell growth. Different research groups have established that LPI is the specific and functional ligand for G-protein-coupled receptor 55 (GPR55) and that this GPR55–LPI axis is able to activate signalling cascades that are relevant for different cell functions. Work in our laboratory has recently unravelled an autocrine loop, by which LPI synthesized by cytosolic phospholipase A2 (cPLA2) is pumped out of the cell by ATP-binding cassette (ABC) transporter C1 (ABCC1)/multidrug resistance protein 1 (MRP1), initiating a signalling cascade downstream of GPR55. Our current work suggests that blockade of this pathway may represent a novel strategy to inhibit cancer cell proliferation.


2021 ◽  
Vol 7 (5) ◽  
pp. 3997-4004
Author(s):  
Zhibo Zou ◽  
Lin Peng

Objective: This study aimed to probe into the effect of LncRNA SNHG14 on ovarian cancer progression by regulating miR-206.Methods: Fifty-seven ovarian cancer (OC) patients who were treated in our hospital from December 2017 to December 2019 were collected as the research objects. During the operation, OC tissues and paracancerous tissues of patients were collected, and the effect of SNHG14 on OC tumor growth in nude mice was detected, and SNHG14 inhibitor was transfected into OC cells. The relative expression of SNHG14 in tissues and cells was detected by qRT-PCR, cell proliferation was testedvia CCK8, migration and invasion were detected through Transwell, apoptosis was assessedvia flow cytometry, and the targeted relationship between SNHG14 and miR-206 was detected by dual luciferase reporter gene.Results: SNHG14 is highly expressed in OC tissues, cells and nude mice. Down-regulating it can inhibit the biological ability of OC cells and inhibit the growth of nude mice tumors. It can directly target miR-206 to regulate CCND1 expression and promote OC progression.Conclusion: LncRNA SNHG14 can act as miR-206 sponge to regulate CCND1 expression downstream of miR-206 and promote OC progression.


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