scholarly journals EHD2 is a mechanotransducer connecting caveolae dynamics with gene transcription

2018 ◽  
Vol 217 (12) ◽  
pp. 4092-4105 ◽  
Author(s):  
Stéphanie Torrino ◽  
Wei-Wei Shen ◽  
Cédric M. Blouin ◽  
Satish Kailasam Mani ◽  
Christine Viaris de Lesegno ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Electron Microscopy ◽  
Gene Regulation ◽  
Plasma Membrane ◽  
Cancer Cells ◽  
Mechanical Stress ◽  
Gene Transcription ◽  
Breast Cancer Cells ◽  
Membrane Tension

Caveolae are small invaginated pits that function as dynamic mechanosensors to buffer tension variations at the plasma membrane. Here we show that under mechanical stress, the EHD2 ATPase is rapidly released from caveolae, SUMOylated, and translocated to the nucleus, where it regulates the transcription of several genes including those coding for caveolae constituents. We also found that EHD2 is required to maintain the caveolae reservoir at the plasma membrane during the variations of membrane tension induced by mechanical stress. Metal-replica electron microscopy of breast cancer cells lacking EHD2 revealed a complete absence of caveolae and a lack of gene regulation under mechanical stress. Expressing EHD2 was sufficient to restore both functions in these cells. Our findings therefore define EHD2 as a central player in mechanotransduction connecting the disassembly of the caveolae reservoir with the regulation of gene transcription under mechanical stress.

scholarly journals EGFR Expression in HER2-Driven Breast Cancer Cells

2020 ◽  
Vol 21 (23) ◽  
pp. 9008
Author(s):  
Florian Weinberg ◽  
Diana B. Peckys ◽  
Niels de Jonge
Keyword(s):  
Breast Cancer ◽  
Electron Microscopy ◽  
Plasma Membrane ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Simultaneous Detection ◽  
Orphan Receptor ◽  
Membrane Expression ◽  
Intact Cells ◽  
Egfr Expression

The epidermal growth factor receptor HER2 is overexpressed in 20% of breast cancer cases. HER2 is an orphan receptor that is activated ligand-independently by homodimerization. In addition, HER2 is able to heterodimerize with EGFR, HER3, and HER4. Heterodimerization has been proposed as a mechanism of resistance to therapy for HER2 overexpressing breast cancer. Here, a method is presented for the simultaneous detection of individual EGFR and HER2 receptors in the plasma membrane of breast cancer cells via specific labeling with quantum dot nanoparticles (QDs). Correlative fluorescence microscopy and liquid phase electron microscopy were used to analyze the plasma membrane expression levels of both receptors in individual intact cells. Fluorescent single-cell analysis of SKBR3 breast cancer cells dual-labeled for EGFR and HER2 revealed a heterogeneous expression for receptors within both the cell population as well as within individual cells. Subsequent electron microscopy of individual cells allowed the determination of individual receptors label distributions. QD-labeled EGFR was observed with a surface density of (0.5–5) × 101 QDs/µm2, whereas labeled HER2 expression was higher ranging from (2–10) × 102 QDs/µm2. Although most SKBR3 cells expressed low levels of EGFR, an enrichment was observed at large plasma membrane protrusions, and amongst a newly discovered cellular subpopulation termed EGFR-enriched cells.

scholarly journals Quantification of EGFR-HER2 Heterodimers in HER2-Overexpressing Breast Cancer Cells Using Liquid-Phase Electron Microscopy

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3244
Author(s):  
Diana B. Peckys ◽  
Daniel Gaa ◽  
Niels de Jonge
Keyword(s):  
Breast Cancer ◽  
Electron Microscopy ◽  
Epidermal Growth Factor Receptor ◽  
Plasma Membrane ◽  
Liquid Phase ◽  
Growth Factor ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Growth Factor Receptor ◽  
Epidermal Growth

Currently, breast cancer patients are classified uniquely according to the expression level of hormone receptors, and human epidermal growth factor receptor 2 (HER2). This coarse classification is insufficient to capture the phenotypic complexity and heterogeneity of the disease. A methodology was developed for absolute quantification of receptor surface density ρR, and molecular interaction (dimerization), as well as the associated heterogeneities, of HER2 and its family member, the epidermal growth factor receptor (EGFR) in the plasma membrane of HER2 overexpressing breast cancer cells. Quantitative, correlative light microscopy (LM) and liquid-phase electron microscopy (LPEM) were combined with quantum dot (QD) labeling. Single-molecule position data of receptors were obtained from scanning transmission electron microscopy (STEM) images of intact cancer cells. Over 280,000 receptor positions were detected and statistically analyzed. An important finding was the subcellular heterogeneity in heterodimer shares with respect to plasma membrane regions with different dynamic properties. Deriving quantitative information about EGFR and HER2 ρR, as well as their dimer percentages, and the heterogeneities thereof, in single cancer cells, is potentially relevant for early identification of patients with HER2 overexpressing tumors comprising an enhanced share of EGFR dimers, likely increasing the risk for drug resistance, and thus requiring additional targeted therapeutic strategies.

scholarly journals Glycosylation Modulates Plasma Membrane Trafficking of CD24 in Breast Cancer Cells

2021 ◽  
Vol 22 (15) ◽  
pp. 8165
Author(s):  
Amanda Chantziou ◽  
Kostas Theodorakis ◽  
Hara Polioudaki ◽  
Eelco de Bree ◽  
Marilena Kampa ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Plasma Membrane ◽  
Subcellular Localization ◽  
Cancer Cells ◽  
Membrane Trafficking ◽  
Breast Cancer Cells ◽  
Endocytic Pathway ◽  
Cell Periphery ◽  
Wild Type ◽  
Mcf 7

In breast cancer, expression of Cluster of Differentiation 24 (CD24), a small GPI-anchored glycoprotein at the cell periphery, is associated with metastasis and immune escape, while its absence is associated with tumor-initiating capacity. Since the mechanism of CD24 sorting is unknown, we investigated the role of glycosylation in the subcellular localization of CD24. Expression and localization of wild type N36- and/or N52-mutated CD24 were analyzed using immunofluorescence in luminal (MCF-7) and basal B (MDA-MB-231 and Hs578T) breast cancer cells lines, as well as HEK293T cells. Endogenous and exogenously expressed wild type and mutated CD24 were found localized at the plasma membrane and the cytoplasm, but not the nucleoplasm. The cell lines showed different kinetics for the sorting of CD24 through the secretory/endocytic pathway. N-glycosylation, especially at N52, and its processing in the Golgi were critical for the sorting and expression of CD24 at the plasma membrane of HEK293T and basal B type cells, but not of MCF-7 cells. In conclusion, our study highlights the contribution of N-glycosylation for the subcellular localization of CD24. Aberrant N-glycosylation at N52 of CD24 could account for the lack of CD24 expression at the cell surface of basal B breast cancer cells.

scholarly journals Mechano-Sensitive Ion Channels (MSCS) Provide Human Breast Cancer Cells with a Sensorium for Mechanical Stress

2014 ◽  
Vol 106 (2) ◽  
pp. 549a-550a
Author(s):  
Chouyang Li ◽  
Simin Rezania ◽  
Sarah Kammerer ◽  
Astrid Gorischek ◽  
Thomas Bauernhofer ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Ion Channels ◽  
Cancer Cells ◽  
Mechanical Stress ◽  
Human Breast Cancer ◽  
Breast Cancer Cells ◽  
Human Breast Cancer Cells ◽  
Human Breast

scholarly journals Interaction of the Anti-Proliferative GPER Inverse Agonist ERα17p with the Breast Cancer Cell Plasma Membrane: From Biophysics to Biology

Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 447 ◽  
Author(s):  
Michaël Trichet ◽  
Rosamaria Lappano ◽  
Mathilde Belnou ◽  
Lilian Salazar Vazquez ◽  
Isabel Alves ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Plasma Membrane ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Breast Cancer Cells ◽  
Direct Interaction ◽  
Lipid Vesicles ◽  
Estrogen Receptor Α ◽  
Cd Spectroscopy

The peptide ERα17p, which corresponds to the 295-311 fragment of the hinge/AF2 domains of the human estrogen receptor α (ERα), exerts apoptosis in breast cancer cells through a mechanism involving the G protein-coupled estrogen-dependent receptor GPER. Besides this receptor-mediated mechanism, we have detected a direct interaction (Kd value in the micromolar range) of this peptide with lipid vesicles mimicking the plasma membrane of eukaryotes. The reversible and not reversible pools of interacting peptide may correspond to soluble and aggregated membrane-interacting peptide populations, respectively. By using circular dichroism (CD) spectroscopy, we have shown that the interaction of the peptide with this membrane model was associated with its folding into β sheet. A slight leakage of the 5(6)-fluorescein was also observed, indicating lipid bilayer permeability. When the peptide was incubated with living breast cancer cells at the active concentration of 10 μM, aggregates were detected at the plasma membrane under the form of spheres. This insoluble pool of peptide, which seems to result from a fibrillation process, is internalized in micrometric vacuoles under the form of fibrils, without evidence of cytotoxicity, at least at the microscopic level. This study provides new information on the interaction of ERα17p with breast cancer cell membranes as well as on its mechanism of action, with respect to direct membrane effects.

scholarly journals Mechanical stress-induced cell death in breast cancer cells

Biology Open ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. bio043133 ◽  
Author(s):  
Satomi Takao ◽  
Minoru Taya ◽  
Cerwyn Chiew
Keyword(s):  
Breast Cancer ◽  
Cell Death ◽  
Cancer Cells ◽  
Mechanical Stress ◽  
Breast Cancer Cells
Sign in / Sign up

Export Citation Format

Share Document