scholarly journals 4168 Understanding ECM-Based Drug Resistivity in Breast Cancer

2020 ◽  
Vol 4 (s1) ◽  
pp. 113-114
Author(s):  
Sarah Libring ◽  
Aparna Shinde ◽  
Miad Boodaghidizaji ◽  
Alexandra Plummer ◽  
Arezoo Ardekani ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Mathematical Model ◽  
Transport Properties ◽  
Growth Rates ◽  
Cellular Response ◽  
Drug Sensitivity ◽  
Survival Rates ◽  
Cell Junctions ◽  
Matrix Interactions ◽  
Cell Cell

OBJECTIVES/GOALS: Cell-cell (CC) and cell-matrix interactions (CM) are known to affect drug sensitivity of cancer cells, but are not effectively recapitulated using 2D platforms. This research aims to determine how cell and matrix interactions confer drug resistivity in 3 distinct culturing models: 2D (no CM/limited CC), 3D spheroids (CC) and 3D fibronectin (both). METHODS/STUDY POPULATION: We examined four breast cancer cell types. The cells were derived from a nonmetastatic primary tumor (HMLE-E2) or overt bone-metastasis (BM). Transglutaminase 2 (TGM2), a matrix crosslinking protein, is overexpressed in metastatic bone tumors and may play a key role in matrix-conferred drug resistivity. In a gain-of-function model, TGM2 was upregulated in HMLE-E2 cells and compared to shTGM2 knockdown BM cells. Growth rates were analyzed using metabolic activity over 8 days, and drug sensitivity to Neratinib (0-1000 nM) was analyzed via cell titer. To account for the different transport properties of the 3 distinct culture environments, we developed a mathematical model for each condition, allowing us to normalize the drug sensitivity results across models to effectively compare true biological resistivity. RESULTS/ANTICIPATED RESULTS: We observed that increased cellular levels of TGM2 significantly increase the growth rate and drug resistivity of cells on fibronectin matrices. Interestingly, in 2D cultures, TGM2 expression was correlated with higher Neratinib resistivity but did not affect growth rates. In spheroid models without a significant matrix component, that rely solely on cell-cell junctions, high levels of TGM2 were correlated with lower survival rates. Lower levels of TGM2 are correlated with a more epithelial phenotype, and using our mathematical model we have identified significant transport differences between high and low TGM2 spheroids. We theorize that the low TGM2 spheroids have denser packing, which lowers the rate of diffusion and, thus reduces the effective concentration of the drug to the majority of the cells. DISCUSSION/SIGNIFICANCE OF IMPACT: Our studies indicate that the cellular response to drugs can be altered by changes in both transport properties of the tissue and the CM interactions. By systematically investigating the effects of CC interactions and CM interactions, we can use mathematical models to delineate physical means of drug resistivity from a biologically driven resistance.

scholarly journals HAX1 impact on collective cell migration, cell adhesion, and cell shape is linked to the regulation of actomyosin contractility

2019 ◽  
Vol 30 (25) ◽  
pp. 3024-3036 ◽  
Author(s):  
Anna Balcerak ◽  
Alicja Trebinska-Stryjewska ◽  
Maciej Wakula ◽  
Mateusz Chmielarczyk ◽  
Urszula Smietanka ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Migration ◽  
Single Cell ◽  
Cancer Progression ◽  
Cancer Cell Line ◽  
Cell Junctions ◽  
Collective Cell Migration ◽  
Actomyosin Contractility ◽  
Epithelial Cell Layer ◽  
Cell Cell

HAX1 protein is involved in the regulation of apoptosis, cell motility and calcium homeostasis. Its overexpression was reported in several tumors, including breast cancer. This study demonstrates that HAX1 has an impact on collective, but not single-cell migration, thus indicating the importance of cell–cell contacts for the HAX1-mediated effect. Accordingly, it was shown that HAX1 knockdown affects cell–cell junctions, substrate adhesion, and epithelial cell layer integrity. As demonstrated here, these effects can be attributed to the modulation of actomyosin contractility through changes in RhoA and septin signaling. Additionally, it was shown that HAX1 does not influence invasive potential in the breast cancer cell line, suggesting that its role in breast cancer progression may be linked instead to collective invasion of the epithelial cells but not single-cell dissemination.

scholarly journals Epithelial Tissues as Active Solids: From Nonlinear Contraction Pulses to Rupture Resistance

2020 ◽  
Author(s):  
Shahaf Armon ◽  
Matthew S. Bull ◽  
Avraham Moriel ◽  
Hillel Aharoni ◽  
Manu Prakash
Keyword(s):  
Mechanical Properties ◽  
Cellular Response ◽  
Cell Junctions ◽  
Emergent Properties ◽  
Reaction Diffusion Systems ◽  
Epithelial Tissues ◽  
Tissue Resistance ◽  
Cell Cell

AbstractEpithelial tissues in many contexts can be viewed as soft active solids. Their active nature is manifested in the ability of individual cells within the tissue to contract and/or remodel their mechanical properties in response to various conditions. Little is known about the emergent properties of such materials. Specifically, how an individual cellular activity gives rise to collective spatiotemporal patterns is not fully understood. Recently we reported the observation of ultrafast contraction pulses in the dorsal epithelium of T.adhaerens in vivo [1] and speculated these propagate via mechanical fields. Other accumulating evidence suggest mechanics is involved in similar contractile patterns in embryonic development in vivo and in cellular monolayers in vitro. Here we show that a widespread cellular response – activation of contraction in response to stretch – is sufficient to give rise to nonlinear propagating contraction pulses. Using a minimal numerical model and theoretical considerations we show how such mechanical pulses emerge and propagate, spontaneously or in response to external stretch. The model – whose mathematical structure resembles that of reaction-diffusion systems – explains observed phenomena in T. adhaerens (e.g. excitable or spontaneous pulses, pulse interaction) and predicts other phenomena (e.g. symmetric strain profile, “spike trains”). Finally, we show that in response to external tension, such an active two-dimensional sheet lowers and dynamically distributes the strains across its surface, hence facilitating tissue resistance to rupture. Adding a cellular softening-threshold further enhances the tissue resistance to rupture at cell-cell junctions. As cohesion is at the heart of epithelial physiology, our model may be relevant to many other epithelial systems, even if manifested at different time/length scales.SignificanceOur work demonstrates that many observed dynamical phenomena in epithelial tissues can be explained merely by mechanical cell-cell interactions, and do not require chemical diffusion or transport between cells (though chemical activity may participate in relevant intracellular processes). Specifically, we show that single cell extension-induced-contraction (EIC) is sufficient to generate propagating contraction pulses, which also increase the tissue’s resistance to rupture, an essential function of epithelia. Our results may shed light on how epithelial tissues function under challenging physiological conditions, e.g. in lung, gut, vasculature and other biomedical contexts. Our results may also be relevant in the study of early evolution of multicellularity and the nervous-muscular systems. Finally, the work offers guidelines for designing soft synthetic solids with improved mechanical properties.

Cell-extracellular matrix interactions and EGF are important regulators of the basal mammary epithelial cell phenotype

1999 ◽  
Vol 112 (7) ◽  
pp. 1035-1044 ◽  
Author(s):  
M.A. Deugnier ◽  
M.M. Faraldo ◽  
P. Rousselle ◽  
J.P. Thiery ◽  
M.A. Glukhova
Keyword(s):  
Extracellular Matrix ◽  
Epithelial Cell ◽  
Mammary Epithelial Cell ◽  
Mammary Epithelial ◽  
Cell Junctions ◽  
Cell Phenotype ◽  
Basal Cells ◽  
Matrix Interactions ◽  
Extracellular Matrix Interactions ◽  
Cell Cell

The mammary epithelium is composed of a luminal epithelium and a basal layer containing myoepithelial cells and undifferentiated precursors. Basal cells express specific protein markers, such as keratin 14 (K14) and P-cadherin. To study the factors that regulate the basal mammary epithelial cell phenotype, we have established two clonal derivatives of the mouse HC11 cell line, BC20 and BC44, expressing high levels of K14 and P-cadherin. Unlike the parental HC11 cells, these basal cells did not produce beta-casein in response to lactogenic hormone treatment; however their phenotype appeared to be plastic. Cultured in EGF-free medium, they exhibited enhanced cell-extracellular matrix adhesions and deficient cell-cell junctions, whereas long-term treatment with EGF induced a decrease of focal contact number and establishment of cell-cell junctions, resulting in downregulation of K14 and P-cadherin expression at the protein and mRNA levels. To determine whether cell-extracellular matrix interactions mediated by integrins have a role in the regulation of the expression of K14 and P-cadherin, the amounts of transcripts for the two proteins were analysed in the basal cells, which were plated on the function-blocking antibodies against beta1 and alpha6 integrin chains, on fibronectin and on laminin 5. The amount of P-cadherin transcript was 2- to 4-fold higher in cells plated on the function-blocking anti-integrin antibodies and on the extracellular matrix proteins, as compared to cells plated on poly-L-lysine, whereas the K14 transcript levels were not significantly modified in response to adhesion. The data demonstrate that integrin-mediated cell interaction with extracellular matrix is directly implicated in the control of P-cadherin expression, and that EGF and cell-extracellular matrix adhesion events are important regulators of the basal mammary epithelial cell phenotype.

scholarly journals RhoC Modulates Cell Junctions and Type I Interferon Response in Aggressive Breast Cancers

2021 ◽  
Vol 11 ◽  
Author(s):  
Hannah G. Abraham ◽  
Peter J. Ulintz ◽  
Laura Goo ◽  
Joel A. Yates ◽  
Andrew C. Little ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Type I Interferon ◽  
Cell Junctions ◽  
Type I ◽  
Breast Cancers ◽  
Wild Type ◽  
Rhoc Gtpase ◽  
Cell Cell

Metastases are the leading cause of death in cancer patients. RhoC, a member of the Rho GTPase family, has been shown to facilitate metastasis of aggressive breast cancer cells by influencing motility, invasion, and chemokine secretion, but as yet there is no integrated model of the precise mechanism of how RhoC promotes metastasis. A common phenotypic characteristic of metastatic cells influenced by these mechanisms is dysregulation of cell-cell junctions. Thus, we set out to study how RhoA- and RhoC-GTPase influence the cell-cell junctions in aggressive breast cancers. We demonstrate that CRISPR-Cas9 knockout of RhoC in SUM 149 and MDA 231 breast cancer cells results in increased normalization of junctional integrity denoted by junction protein expression/colocalization. In functional assessments of junction stability, RhoC knockout cells have increased barrier integrity and increased cell-cell adhesion compared to wild-type cells. Whole exome RNA sequencing and targeted gene expression profiling demonstrate decreased expression of Type I interferon-stimulated genes in RhoC knockout cells compared to wild-type, and subsequent treatment with interferon-alpha resulted in significant increases in adhesion and decreases in invasiveness of wild-type cells and a dampened response to interferon-alpha stimulation with respect to adhesion and invasiveness in RhoC knockout cells. We delineate a key role of RhoC-GTPase in modulation of junctions and response to interferon, which supports inhibition of RhoC as a potential anti-invasion therapeutic strategy.

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