1
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Kaczmarczyk O, Augustyniak D, Żak A. Imaging of Hydrated and Living Cells in Transmission Electron Microscope: Summary, Challenges, and Perspectives. ACS NANO 2025; 19:12710-12733. [PMID: 40156542 PMCID: PMC11984313 DOI: 10.1021/acsnano.5c00871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2025] [Revised: 03/11/2025] [Accepted: 03/13/2025] [Indexed: 04/01/2025]
Abstract
Transmission electron microscopy (TEM) is well-known for performing in situ studies in the nanoscale. Hence, scientists took this opportunity to explore the subtle processes occurring in living organisms. Nevertheless, such observations are complex─they require delicate samples kept in the liquid phase, low electron dose, and proper cell viability verification methods. Despite being highly demanding, so-called "live-cell" experiments have seen some degree of success. The presented review consists of an exhaustive literature review on reported "live-cell" studies and associated subjects, including liquid phase imaging, electron radiation interactions with liquids, and methods for cell viability testing. The challenges of modern, reliable research on living organisms are widely explained and discussed, and future perspectives for developing these techniques are presented.
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Affiliation(s)
- Olga Kaczmarczyk
- Institute
of Advanced Materials, Wroclaw University
of Science and Technology, 50-370 Wroclaw, Poland
| | - Daria Augustyniak
- Department
of Pathogen Biology and Immunology, Faculty of Biological Sciences, University of Wroclaw, 51-148 Wroclaw, Poland
| | - Andrzej Żak
- Institute
of Advanced Materials, Wroclaw University
of Science and Technology, 50-370 Wroclaw, Poland
- Department
of Material Science and Engineering, Massachusetts
Institute of Science and Technology, Cambridge, Massachusetts 02139, United States
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2
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Caffrey BJ, Pedrazo‐Tardajos A, Liberti E, Gaunt B, Kim JS, Kirkland AI. Liquid Phase Electron Microscopy of Bacterial Ultrastructure. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2402871. [PMID: 39239997 PMCID: PMC11636060 DOI: 10.1002/smll.202402871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 06/05/2024] [Indexed: 09/07/2024]
Abstract
Recent advances in liquid phase scanning transmission electron microscopy (LP-STEM) have enabled the study of dynamic biological processes at nanometer resolutions, paving the way for live-cell imaging using electron microscopy. However, this technique is often hampered by the inherent thickness of whole cell samples and damage from electron beam irradiation. These restrictions degrade image quality and resolution, impeding biological interpretation. Using graphene encapsulation, scanning transmission electron microscopy (STEM), and energy-dispersive X-ray (EDX) spectroscopy to mitigate these issues provides unprecedented levels of intracellular detail in aqueous specimens. This study demonstrates the potential of LP-STEM to examine and identify internal cellular structures in thick biological samples. Specifically, it highlights the use of LP-STEM to investigate the radiation resistant, gram-positive bacterium, Deinococcus radiodurans using various imaging techniques.
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Affiliation(s)
- Brian J. Caffrey
- The Rosalind Franklin InstituteHarwell Science and Innovation CampusDidcotOX11 OQXUK
| | | | - Emanuela Liberti
- The Rosalind Franklin InstituteHarwell Science and Innovation CampusDidcotOX11 OQXUK
| | - Benjamin Gaunt
- The Rosalind Franklin InstituteHarwell Science and Innovation CampusDidcotOX11 OQXUK
- Nuffield Department of Women's & Reproductive HealthUniversity of OxfordJohn Radcliffe HospitalOxfordOX3 9DUUK
| | - Judy S. Kim
- The Rosalind Franklin InstituteHarwell Science and Innovation CampusDidcotOX11 OQXUK
- Department of MaterialsUniversity of OxfordOxfordOX1 3PHUK
| | - Angus I. Kirkland
- The Rosalind Franklin InstituteHarwell Science and Innovation CampusDidcotOX11 OQXUK
- Department of MaterialsUniversity of OxfordOxfordOX1 3PHUK
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3
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Bartels N, van der Voort NTM, Opanasyuk O, Felekyan S, Greife A, Shang X, Bister A, Wiek C, Seidel CAM, Monzel C. Advanced multiparametric image spectroscopy and super-resolution microscopy reveal a minimal model of CD95 signal initiation. SCIENCE ADVANCES 2024; 10:eadn3238. [PMID: 39213362 PMCID: PMC11809610 DOI: 10.1126/sciadv.adn3238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 07/26/2024] [Indexed: 09/04/2024]
Abstract
Unraveling the concentration-dependent spatiotemporal organization of receptors in the plasma membrane is crucial to understand cell signal initiation. A paradigm of this process is the oligomerization of CD95 during apoptosis signaling, with different oligomerization models being discussed. Here, we establish the molecular-sensitive approach cell lifetime Förster resonance energy transfer image spectroscopy to determine CD95 configurations in live cells. These data are corroborated by stimulated emission depletion microscopy, confocal photobleaching step analysis, and fluorescence correlation spectroscopy. We probed CD95 interactions for concentrations of ~10 to 1000 molecules per square micrometer, over nanoseconds to hours, and molecular to cellular scales. Quantitative benchmarking was achieved establishing high-fidelity monomer and dimer controls. While CD95 alone is primarily monomeric (~96%) and dimeric (4%), the addition of ligand induces oligomerization to dimers/trimers (~15%) leading to cell death. This study highlights molecular concentration effects and oligomerization dynamics. It reveals a minimal model, where small CD95 oligomers suffice to efficiently initiate signaling.
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Affiliation(s)
- Nina Bartels
- Experimental Medical Physics, Heinrich-Heine University, Düsseldorf, Germany
| | | | - Oleg Opanasyuk
- Molecular Physical Chemistry, Heinrich-Heine University, Düsseldorf, Germany
| | - Suren Felekyan
- Molecular Physical Chemistry, Heinrich-Heine University, Düsseldorf, Germany
| | - Annemarie Greife
- Molecular Physical Chemistry, Heinrich-Heine University, Düsseldorf, Germany
| | - Xiaoyue Shang
- Experimental Medical Physics, Heinrich-Heine University, Düsseldorf, Germany
| | - Arthur Bister
- Department of Otorhinolaryngology, Head & Neck Surgery, Heinrich-Heine University, Düsseldorf, Germany
| | - Constanze Wiek
- Department of Otorhinolaryngology, Head & Neck Surgery, Heinrich-Heine University, Düsseldorf, Germany
| | - Claus A. M. Seidel
- Molecular Physical Chemistry, Heinrich-Heine University, Düsseldorf, Germany
| | - Cornelia Monzel
- Experimental Medical Physics, Heinrich-Heine University, Düsseldorf, Germany
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4
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Pham CV, Chowdhury R, Patel S, Melke H, Hou Y, Xu H, Jia L, Duan A, Duan W, Xiang D. The role of the size of affinity ligands in the detection and characterization of extracellular vesicles. Biosens Bioelectron 2024; 258:116381. [PMID: 38744116 DOI: 10.1016/j.bios.2024.116381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 04/15/2024] [Accepted: 05/10/2024] [Indexed: 05/16/2024]
Abstract
Surface proteins on the membrane of nano-sized extracellular vesicles (EVs) not only play crucial roles in cell-to-cell communication, but also are specific binding targets for EV detection, isolation and tracking. The low abundance of protein biomarkers on EV surface, the formation of clusters and the complex EV surface network impose significant challenges to the study of EVs. Employing bulky sized affinity ligands, such as antibodies, in the detection and characterization of these vesicles often result in reduced sensitivity of detection or poor quantification of proteins on the EV surface. By virtue of their small size and high specificity, Affibody molecules emerge as a potential alternative to their monoclonal antibody counterparts as robust affinity ligands in EV research. In this study, we present a theoretical framework on the superiority of anti-HER2 Affibodies over anti-HER2 antibodies in labeling and detecting HER2-positive EVs, followed by the demonstration of the advantages of HER2 Affibodies in accessing EV surface and the detection of EVs through multiple types of approaches including fluorescence intensity, colorimetry, and fluorescence polarization. HER2 Affibodies outperformed by 10-fold over three HER2 antibody clones in accessing HER2-positive EVs derived from different human cancer cell lines. Furthermore, HRP-Affibody molecules could detect EVs from cancer cells spiked into human serum with at least a 2-fold higher sensitivity compared with that of their antibody counterparts. In addition, in fluorescence polarization assays in which no separation of free from bound ligand is required, FITC-labeled HER2 Affibodies could sensitively detect HER2-positive EVs with a clinically relevant limit of detection, whilst HER2 antibodies failed to detect EVs in the same conditions. With the demonstrated superiority in accessing and detecting surface targets over bulky-sized antibodies in EVs, Affibodies may become the next-generation of affinity ligands in the precise characterization and quantification of molecular architecture on the surface of EVs.
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Affiliation(s)
- Cuong Viet Pham
- School of Medicine, Deakin University, and IMPACT Strategic Research Centre, Waurn Ponds, VIC, 3216, Australia
| | - Rocky Chowdhury
- School of Medicine, Deakin University, and IMPACT Strategic Research Centre, Waurn Ponds, VIC, 3216, Australia
| | - Shweta Patel
- School of Medicine, Deakin University, and IMPACT Strategic Research Centre, Waurn Ponds, VIC, 3216, Australia
| | - Haben Melke
- School of Medicine, Deakin University, and IMPACT Strategic Research Centre, Waurn Ponds, VIC, 3216, Australia
| | - Yingchu Hou
- Laboratory of Tumor Molecular and Cellular Biology College of Life Sciences, Shaanxi Normal University 620 West Chang'an Avenue, Xi'an, Shaanxi, 710119, China
| | - Huo Xu
- College of Materials and Chemical Engineering, Minjiang University, Fuzhou, Fujian, 350108, China
| | - Lee Jia
- College of Materials and Chemical Engineering, Minjiang University, Fuzhou, Fujian, 350108, China
| | - Andrew Duan
- Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Vic, Australia
| | - Wei Duan
- School of Medicine, Deakin University, and IMPACT Strategic Research Centre, Waurn Ponds, VIC, 3216, Australia.
| | - Dongxi Xiang
- State Key Laboratory of Oncogenes and Related Genes, Department of Biliary-Pancreatic Surgery, The Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China.
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5
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Taylor RP, Lindorfer MA. Antibody-drug conjugate adverse effects can be understood and addressed based on immune complex clearance mechanisms. Blood 2024; 144:137-144. [PMID: 38643493 DOI: 10.1182/blood.2024024442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 04/10/2024] [Accepted: 04/15/2024] [Indexed: 04/23/2024] Open
Abstract
ABSTRACT Numerous antibody-drug conjugates (ADCs) are being developed for cancer immunotherapy. Although several of these agents have demonstrated considerable clinical efficacy and have won Food and Drug Administration (FDA) approval, in many instances, they have been characterized by adverse side effects (ASEs), which can be quite severe in a fraction of treated patients. The key hypothesis in this perspective is that many of the most serious ASEs associated with the use of ADCs in the treatment of cancer can be most readily explained and understood due to the inappropriate processing of these ADCs via pathways normally followed for immune complex clearance, which include phagocytosis and trogocytosis. We review the key published basic science experiments and clinical observations that support this idea. We propose that it is the interaction of the ADC with Fcγ receptors expressed on off-target cells and tissues that can most readily explain ADC-mediated pathologies, which therefore provides a rationale for the design of protocols to minimize ASEs. We describe measurements that should help identify those patients most likely to experience ASE due to ADC, and we propose readily available treatments as well as therapies under development for other indications that should substantially reduce ASE associated with ADC. Our focus will be on the following FDA-approved ADC for which there are substantial literatures: gemtuzumab ozogamicin and inotuzumab ozogamicin; and trastuzumab emtansine and trastuzumab deruxtecan.
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Affiliation(s)
- Ronald P Taylor
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA
| | - Margaret A Lindorfer
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA
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6
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Ruedas R, Vuillemot R, Tubiana T, Winter JM, Pieri L, Arteni AA, Samson C, Jonic S, Mathieu M, Bressanelli S. Structure and conformational variability of the HER2-trastuzumab-pertuzumab complex. J Struct Biol 2024; 216:108095. [PMID: 38723875 DOI: 10.1016/j.jsb.2024.108095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Revised: 03/11/2024] [Accepted: 04/24/2024] [Indexed: 05/13/2024]
Abstract
Single particle analysis from cryogenic transmission electron microscopy (cryo-EM) is particularly attractive for complexes for which structure prediction remains intractable, such as antibody-antigen complexes. Here we obtain the detailed structure of a particularly difficult complex between human epidermal growth factor receptor 2 (HER2) and the antigen-binding fragments from two distinct therapeutic antibodies binding to distant parts of the flexible HER2, pertuzumab and trastuzumab (HTP). We highlight the strengths and limitations of current data processing software in dealing with various kinds of heterogeneities, particularly continuous conformational heterogeneity, and in describing the motions that can be extracted from our dataset. Our HTP structure provides a more detailed view than the one previously available for this ternary complex. This allowed us to pinpoint a previously overlooked loop in domain IV that may be involved both in binding of trastuzumab and in HER2 dimerization. This finding may contribute to explain the synergistic anticancer effect of the two antibodies. We further propose that the flexibility of the HTP complex, beyond the difficulties it causes for cryo-EM analysis, actually reflects regulation of HER2 signaling and its inhibition by therapeutic antibodies. Notably we obtain our best data with ultra-thin continuous carbon grids, showing that with current cameras their use to alleviate particle misdistribution is compatible with a protein complex of only 162 kDa. Perhaps most importantly, we provide here a dataset for such a smallish protein complex for further development of software accounting for continuous conformational heterogeneity in cryo-EM images.
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Affiliation(s)
- Rémi Ruedas
- Université Paris-Saclay, CEA, CNRS - Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France; Sanofi, Integrated Drug Discovery, 13, quai Jules Guesde 94403, Vitry-sur-Seine, France
| | - Rémi Vuillemot
- IMPMC-UMR 7590 CNRS, Sorbonne Université, Muséum National d'Histoire Naturelle, 75005, Paris, France
| | - Thibault Tubiana
- Université Paris-Saclay, CEA, CNRS - Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Jean-Marie Winter
- NanoImaging Core Facility, Centre de Ressources et Recherches Technologiques (C2RT), Institut Pasteur, 75015, Paris, France
| | - Laura Pieri
- Université Paris-Saclay, CEA, CNRS - Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Ana-Andreea Arteni
- Université Paris-Saclay, CEA, CNRS - Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Camille Samson
- Sanofi, Integrated Drug Discovery, 13, quai Jules Guesde 94403, Vitry-sur-Seine, France
| | - Slavica Jonic
- IMPMC-UMR 7590 CNRS, Sorbonne Université, Muséum National d'Histoire Naturelle, 75005, Paris, France
| | - Magali Mathieu
- Sanofi, Integrated Drug Discovery, 13, quai Jules Guesde 94403, Vitry-sur-Seine, France
| | - Stéphane Bressanelli
- Université Paris-Saclay, CEA, CNRS - Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France.
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7
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Erazo-Oliveras A, Muñoz-Vega M, Salinas ML, Wang X, Chapkin RS. Dysregulation of cellular membrane homeostasis as a crucial modulator of cancer risk. FEBS J 2024; 291:1299-1352. [PMID: 36282100 PMCID: PMC10126207 DOI: 10.1111/febs.16665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 09/09/2022] [Accepted: 10/24/2022] [Indexed: 11/07/2022]
Abstract
Cellular membranes serve as an epicentre combining extracellular and cytosolic components with membranous effectors, which together support numerous fundamental cellular signalling pathways that mediate biological responses. To execute their functions, membrane proteins, lipids and carbohydrates arrange, in a highly coordinated manner, into well-defined assemblies displaying diverse biological and biophysical characteristics that modulate several signalling events. The loss of membrane homeostasis can trigger oncogenic signalling. More recently, it has been documented that select membrane active dietaries (MADs) can reshape biological membranes and subsequently decrease cancer risk. In this review, we emphasize the significance of membrane domain structure, organization and their signalling functionalities as well as how loss of membrane homeostasis can steer aberrant signalling. Moreover, we describe in detail the complexities associated with the examination of these membrane domains and their association with cancer. Finally, we summarize the current literature on MADs and their effects on cellular membranes, including various mechanisms of dietary chemoprevention/interception and the functional links between nutritional bioactives, membrane homeostasis and cancer biology.
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Affiliation(s)
- Alfredo Erazo-Oliveras
- Program in Integrative Nutrition and Complex Diseases; Texas A&M University; College Station, Texas, 77843; USA
- Department of Nutrition; Texas A&M University; College Station, Texas, 77843; USA
| | - Mónica Muñoz-Vega
- Program in Integrative Nutrition and Complex Diseases; Texas A&M University; College Station, Texas, 77843; USA
- Department of Nutrition; Texas A&M University; College Station, Texas, 77843; USA
| | - Michael L. Salinas
- Program in Integrative Nutrition and Complex Diseases; Texas A&M University; College Station, Texas, 77843; USA
- Department of Nutrition; Texas A&M University; College Station, Texas, 77843; USA
| | - Xiaoli Wang
- Program in Integrative Nutrition and Complex Diseases; Texas A&M University; College Station, Texas, 77843; USA
- Department of Nutrition; Texas A&M University; College Station, Texas, 77843; USA
| | - Robert S. Chapkin
- Program in Integrative Nutrition and Complex Diseases; Texas A&M University; College Station, Texas, 77843; USA
- Department of Nutrition; Texas A&M University; College Station, Texas, 77843; USA
- Center for Environmental Health Research; Texas A&M University; College Station, Texas, 77843; USA
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8
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Shaban N, Raevskiy M, Zakharova G, Shipunova V, Deyev S, Suntsova M, Sorokin M, Buzdin A, Kamashev D. Human Blood Serum Counteracts EGFR/HER2-Targeted Drug Lapatinib Impact on Squamous Carcinoma SK-BR-3 Cell Growth and Gene Expression. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:487-506. [PMID: 38648768 DOI: 10.1134/s000629792403009x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 01/17/2024] [Accepted: 02/20/2024] [Indexed: 04/25/2024]
Abstract
Lapatinib is a targeted therapeutic inhibiting HER2 and EGFR proteins. It is used for the therapy of HER2-positive breast cancer, although not all the patients respond to it. Using human blood serum samples from 14 female donors (separately taken or combined), we found that human blood serum dramatically abolishes the lapatinib-mediated inhibition of growth of the human breast squamous carcinoma SK-BR-3 cell line. This antagonism between lapatinib and human serum was associated with cancelation of the drug induced G1/S cell cycle transition arrest. RNA sequencing revealed 308 differentially expressed genes in the presence of lapatinib. Remarkably, when combined with lapatinib, human blood serum showed the capacity of restoring both the rate of cell growth, and the expression of 96.1% of the genes expression of which were altered by the lapatinib treatment alone. Co-administration of EGF with lapatinib also restores the cell growth and cancels alteration of expression of 95.8% of the genes specific to lapatinib treatment of SK-BR-3 cells. Differential gene expression analysis also showed that in the presence of human serum or EGF, lapatinib was unable to inhibit the Toll-Like Receptor signaling pathway and alter expression of genes linked to the Gene Ontology term of Focal adhesion.
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Affiliation(s)
- Nina Shaban
- Moscow Institute of Physics and Technology, Dolgoprudny, 141701, Russia.
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia
- The National Medical Research Center for Endocrinology, Moscow, 117036, Russia
| | - Mikhail Raevskiy
- World-Class Research Center "Digital Biodesign and Personalized Healthcare", Sechenov First Moscow State Medical University, Moscow, 119991, Russia.
| | - Galina Zakharova
- World-Class Research Center "Digital Biodesign and Personalized Healthcare", Sechenov First Moscow State Medical University, Moscow, 119991, Russia.
| | - Victoria Shipunova
- Moscow Institute of Physics and Technology, Dolgoprudny, 141701, Russia.
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia
| | - Sergey Deyev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia.
- "Biomarker" Research Laboratory, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, 420008, Russia
| | - Maria Suntsova
- The National Medical Research Center for Endocrinology, Moscow, 117036, Russia.
- Sechenov First Moscow State Medical University, Moscow, 119991, Russia
| | - Maksim Sorokin
- Moscow Institute of Physics and Technology, Dolgoprudny, 141701, Russia.
- Sechenov First Moscow State Medical University, Moscow, 119991, Russia
- PathoBiology Group, European Organization for Research and Treatment of Cancer (EORTC), Brussels, 1200, Belgium
| | - Anton Buzdin
- Moscow Institute of Physics and Technology, Dolgoprudny, 141701, Russia.
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia
- The National Medical Research Center for Endocrinology, Moscow, 117036, Russia
- World-Class Research Center "Digital Biodesign and Personalized Healthcare", Sechenov First Moscow State Medical University, Moscow, 119991, Russia
| | - Dmitri Kamashev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia.
- The National Medical Research Center for Endocrinology, Moscow, 117036, Russia
- Sechenov First Moscow State Medical University, Moscow, 119991, Russia
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9
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Moradi Y, Lee JSH, Armani AM. Detecting Disruption of HER2 Membrane Protein Organization in Cell Membranes with Nanoscale Precision. ACS Sens 2024; 9:52-61. [PMID: 37955934 PMCID: PMC10825864 DOI: 10.1021/acssensors.3c01437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 10/25/2023] [Accepted: 10/30/2023] [Indexed: 11/14/2023]
Abstract
The spatiotemporal organization of proteins within the cell membrane can affect numerous biological functions, including cell signaling, communication, and transportation. Deviations from normal spatial arrangements have been observed in various diseases, and a better understanding of this process is a key stepping stone to advancing development of clinical interventions. However, given the nanometer length scales involved, detecting these subtle changes has primarily relied on complex super-resolution and single-molecule imaging methods. In this work, we demonstrate an alternative fluorescent imaging strategy for detecting protein organization based on a material that exhibits a unique photophysical behavior known as aggregation-induced emission (AIE). Organic AIE molecules have an increase in emission signal when they are in close proximity, and the molecular motion is restricted. This property simultaneously addresses the high background noise and low detection signal that limit conventional widefield fluorescent imaging. To demonstrate the potential of this approach, the fluorescent molecule sensor is conjugated to a human epidermal growth factor receptor 2 (HER2)-specific antibody and used to investigate the spatiotemporal behavior of HER2 clustering in the membrane of HER2-overexpressing breast cancer cells. Notably, the disruption of HER2 clusters in response to an FDA-approved monoclonal antibody therapeutic (Trastuzumab) is successfully detected using a simple widefield fluorescent microscope. While the sensor demonstrated here is optimized for sensing HER2 clustering, it is an easily adaptable platform. Moreover, given the compatibility with widefield imaging, the system has the potential to be used with high-throughput imaging techniques, accelerating investigations into membrane protein spatiotemporal organization.
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Affiliation(s)
- Yasaman Moradi
- Mork
Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089, United States
- Ellison
Institute of Technology, Los Angeles, California 90064, United States
| | - Jerry S. H. Lee
- Mork
Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089, United States
- Ellison
Institute of Technology, Los Angeles, California 90064, United States
- Keck
School of Medicine, University of Southern
California, Los Angeles, California 90089, United States
| | - Andrea M. Armani
- Mork
Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089, United States
- Ellison
Institute of Technology, Los Angeles, California 90064, United States
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10
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Wu YL, Lee K, Diloknawarit B, Odom TW. Ligand Separation on Nanoconstructs Affects Targeting Selectivity to Protein Dimers on Cell Membranes. NANO LETTERS 2024; 24:519-524. [PMID: 38126338 PMCID: PMC11252445 DOI: 10.1021/acs.nanolett.3c04641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
This work demonstrates that targeting ligand density on nanoparticles can affect interactions between the nanoconstructs and cell membrane receptors. We discovered that when the separation between covalently grafted DNA aptamers on gold nanostars was comparable to the distance between binding sites on a receptor dimer (matched density; MD), nanoconstructs exhibited a higher selectivity for binding to the dimeric form of the protein. Single-particle dynamics of MD nanoconstructs showed slower rotational rates and larger translational footprints on cancer cells expressing more dimeric forms of receptors (dimer+) compared with cells having more monomeric forms (dimer-). In contrast, nanoconstructs with either increased (nonmatched density; NDlow) or decreased ligand spacing (NDhigh) had minimal changes in dynamics on either dimer+ or dimer- cells. Real-time, single-particle analyses can reveal the importance of nanoconstruct ligand density for the selective targeting of membrane receptors in live cells.
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Affiliation(s)
- Yuhao Leo Wu
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Kwahun Lee
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
- Department of Chemistry and Chemical Biology, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States
| | - Bundit Diloknawarit
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Teri W Odom
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
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11
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Wakefield DL, Golfetto O, Jorand R, Biswas S, Meyer K, Avery KN, Zer C, Cacao EE, Tobin SJ, Talisman IJ, Williams JC, Jovanovic-Talisman T. Using quantitative single molecule localization microscopy to optimize multivalent HER2-targeting ligands. Front Med (Lausanne) 2023; 10:1064242. [PMID: 37138747 PMCID: PMC10149953 DOI: 10.3389/fmed.2023.1064242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Accepted: 03/30/2023] [Indexed: 05/05/2023] Open
Abstract
Introduction The progression-free survival of patients with HER2-positive metastatic breast cancer is significantly extended by a combination of two monoclonal antibodies, trastuzumab and pertuzumab, which target independent epitopes of the extracellular domain of HER2. The improved efficacy of the combination over individual antibody therapies targeting HER2 is still being investigated, and several molecular mechanisms may be in play: the combination downregulates HER2, improves antibody-dependent cell mediated cytotoxicity, and/or affects the organization of surface-expressed antigens, which may attenuate downstream signaling. Methods By combining protein engineering and quantitative single molecule localization microscopy (qSMLM), here we both assessed and optimized clustering of HER2 in cultured breast cancer cells. Results We detected marked changes to the cellular membrane organization of HER2 when cells were treated with therapeutic antibodies. When we compared untreated samples to four treatment scenarios, we observed the following HER2 membrane features: (1) the monovalent Fab domain of trastuzumab did not significantly affect HER2 clustering; (2) individual therapy with either trastuzumab or (3) pertuzumab produced significantly higher levels of HER2 clustering; (4) a combination of trastuzumab plus pertuzumab produced the highest level of HER2 clustering. To further enhance this last effect, we created multivalent ligands using meditope technology. Treatment with a tetravalent meditope ligand combined with meditope-enabled trastuzumab resulted in pronounced HER2 clustering. Moreover, compared to pertuzumab plus trastuzumab, at early time points this meditope-based combination was more effective at inhibiting epidermal growth factor (EGF) dependent activation of several downstream protein kinases. Discussion Collectively, mAbs and multivalent ligands can efficiently alter the organization and activation of the HER2 receptors. We expect this approach could be used in the future to develop new therapeutics.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - John C. Williams
- Department of Cancer Biology and Molecular Medicine, Beckman Research Institute, Duarte, CA, United States
| | - Tijana Jovanovic-Talisman
- Department of Cancer Biology and Molecular Medicine, Beckman Research Institute, Duarte, CA, United States
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12
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Bai X, Sun P, Wang X, Long C, Liao S, Dang S, Zhuang S, Du Y, Zhang X, Li N, He K, Zhang Z. Structure and dynamics of the EGFR/HER2 heterodimer. Cell Discov 2023; 9:18. [PMID: 36781849 PMCID: PMC9925823 DOI: 10.1038/s41421-023-00523-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 01/15/2023] [Indexed: 02/15/2023] Open
Abstract
HER2 belongs to the human epidermal growth factor receptor tyrosine kinase family. Its overexpression or hyperactivation is a leading cause for multiple types of cancers. HER2 functions mainly through dimerization with other family members, such as EGFR. However, the molecular details for heterodimer assembly have not been completely understood. Here, we report cryo-EM structures of the EGF- and epiregulin-bound EGFR/HER2 ectodomain complexes at resolutions of 3.3 Å and 4.5 Å, respectively. Together with the functional analyses, we demonstrate that only the dimerization arm of HER2, but not that of EGFR, is essential for their heterodimer formation and signal transduction. Moreover, we analyze the differential membrane dynamics and transient interactions of endogenous EGFR and HER2 molecules in genome-edited cells using single-molecule live-cell imaging. Furthermore, we show that the interaction with HER2 could allow EGFR to resist endocytosis. Together, this work deepens our understanding of the unique structural properties and dynamics of the EGFR/HER2 complex.
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Affiliation(s)
- Xue Bai
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing, China
| | - Pengyu Sun
- grid.9227.e0000000119573309State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, China
| | - Xinghao Wang
- grid.9227.e0000000119573309State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, China
| | - Changkun Long
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing, China
| | - Shuyun Liao
- grid.11135.370000 0001 2256 9319Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Song Dang
- grid.9227.e0000000119573309State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Shangshang Zhuang
- grid.9227.e0000000119573309State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, China
| | - Yongtao Du
- grid.9227.e0000000119573309State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, China
| | - Xinyi Zhang
- grid.9227.e0000000119573309State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, China
| | - Nan Li
- grid.9227.e0000000119573309State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Kangmin He
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China. .,University of Chinese Academy of Sciences, Beijing, China.
| | - Zhe Zhang
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing, China. .,Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.
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13
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Petrov M, Sokolov I. Identification of Geometrical Features of Cell Surface Responsible for Cancer Aggressiveness: Machine Learning Analysis of Atomic Force Microscopy Images of Human Colorectal Epithelial Cells. Biomedicines 2023; 11:191. [PMID: 36672699 PMCID: PMC9855899 DOI: 10.3390/biomedicines11010191] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 01/05/2023] [Accepted: 01/09/2023] [Indexed: 01/15/2023] Open
Abstract
It has been recently demonstrated that atomic force microscopy (AFM) allows for the rather precise identification of malignancy in bladder and cervical cells. Furthermore, an example of human colorectal epithelial cells imaged in AFM Ringing mode has demonstrated the ability to distinguish cells with varying cancer aggressiveness with the help of machine learning (ML). The previously used ML methods analyzed the entire cell image. The problem with such an approach is the lack of information about which features of the cell surface are associated with a high degree of aggressiveness of the cells. Here we suggest a machine-learning approach to overcome this problem. Our approach identifies specific geometrical regions on the cell surface that are critical for classifying cells as highly or lowly aggressive. Such localization gives a path to colocalize the newly identified features with possible clustering of specific molecules identified via standard bio-fluorescence imaging. The biological interpretation of the obtained information is discussed.
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Affiliation(s)
- Mikhail Petrov
- Department of Mechanical Engineering, Tufts University, Medford, MA 02155, USA
| | - Igor Sokolov
- Department of Mechanical Engineering, Tufts University, Medford, MA 02155, USA
- Department of Physics, Tufts University, Medford, MA 02155, USA
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14
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Li X, Zhu J, Shi X, Wang Z, Chen X, Zhang X, Chen Y. Steric Hindrance On-Off Mass-Tagged Probe Set Enables Detection of Protein Homodimer in Living Cells. ACS APPLIED MATERIALS & INTERFACES 2022; 14:54517-54526. [PMID: 36449938 DOI: 10.1021/acsami.2c15010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The major challenge in the detection of protein homodimers is that the identical monomers in a homodimer are indistinguishable using most conventional methods and cannot be sequentially recognized. In this study, a steric hindrance on-off mass-tagged probe set strategy was developed for the quantification of HER2 homodimer in living cells. The probe set contained a hindrance probe and a detection probe. The hindrance probe had a DNA dendrimer as a hindrance group to achieve the steric hindrance on-off function and thus the assignment of monomer identity. The detection probe contained a mass tag released for mass spectrometric quantification. Using the steric hindrance on-off mass-tagged probe set, the level of HER2 homodimer in various breast cancer cell lines was quantified. This is the first report to determine the quantity of protein homodimers, and the steric hindrance on-off probe set developed herein can facilitate the illustration of protein function in cancer.
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Affiliation(s)
- Xiaoxu Li
- School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Jianhua Zhu
- School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Xiaoyu Shi
- School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Zhongcheng Wang
- School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Xi Chen
- School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Xian Zhang
- School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Yun Chen
- School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 210029, China
- Key Laboratory of Cardiovascular & Cerebrovascular Medicine, Nanjing Medical University, Nanjing 211166, China
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15
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Najjari N, Sari S, Saffari M, Kelidari H, Nokhodchi A. Formulation optimization and characterization of Pistacia atlantica Desf. essential oil-loaded nanostructured lipid carriers on the proliferation of human breast cancer cell line SKBR3 (in vitro studies). J Herb Med 2022. [DOI: 10.1016/j.hermed.2022.100600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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16
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Liu L, Chen X, Sun B. Construction of a Recyclable DNAzyme Motor for MUC1-Specific Glycoform In Situ Quantification. Anal Chem 2022; 94:13745-13752. [PMID: 36161871 DOI: 10.1021/acs.analchem.2c01961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Changes in the glycosylation content, especially in specific proteins, are of great importance for interpreting the mechanisms and development of certain diseases. However, current detection techniques are limited by the weak ionization efficiency of glycosyls and poor anti-interference of fluorescence signals. Herein, we present a general in situ quantification strategy for protein-specific glycoforms by constructing a recyclable DNAzyme motor for mass spectrometric detection using MUC1-specific sialic acid (Sia) as a model. This approach relies on a DNAzyme-based recycling strategy and two well-designed probes: a protein and a glycan probe. The protein probe consists of an aptamer and a DNAzyme. The glycan probe contains three functional domains: a DNAzyme complementary sequence, a substrate peptide segment, and a dibenzocyclooctyne tag. First, these two probes bind to their corresponding targets and trigger hybridization between adjacent probes on the same protein. With the help of the metal cofactor, the DNAzyme of the protein probe hydrolyzes the double-stranded glycan probe. The protein probe then reverts to a single-stranded state and remains intact for the next round of hybridization and cleavage. In this way, the recyclable DNAzyme motor can hydrolyze all glycan probes bound to the target protein. Finally, the reporter peptide released from the hydrolyzed glycan probes can be quantified by mass spectrometry, thereby converting the signal of the protein-specific glycoform to that of mass spectrometry. This strategy has been successfully used for in situ quantification of MUC1-specific Sia in different breast cancer cell lines. It provides a promising platform for protein-specific glycoform quantification.
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Affiliation(s)
- Liang Liu
- Department of Pharmacy, Zhongnan Hospital of Wuhan University, Wuhan 430071, China
| | - Xiuyu Chen
- School of Pharmacy, Nanjing Medical University, Nanjing 211166, China
| | - Bo Sun
- Department of Pharmacy, The First People's Hospital of Lianyungang, Lianyungang 222000, China
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17
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Moasser MM. Inactivating amplified HER2: challenges, dilemmas, and future directions. Cancer Res 2022; 82:2811-2820. [PMID: 35731927 DOI: 10.1158/0008-5472.can-22-1121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/10/2022] [Accepted: 06/15/2022] [Indexed: 11/16/2022]
Abstract
The pharmaceutical inactivation of driver oncogenes has revolutionized the treatment of cancer replacing cytotoxic chemotherapeutic approaches with kinase inhibitor therapies for many types of cancers. This approach has not yet been realized for the treatment of HER2-amplified cancers. The monotherapy activities associated with HER2-targeting antibodies and kinase inhibitors are modest, and their clinical use has been in combination with, and not in replacement of cytotoxic chemotherapies. This stands in sharp contrast to achievements in the treatment of many other oncogene-driven cancers. The mechanism-based treatment hypothesis regarding the inactivation of HER2 justifies expectations far beyond what is currently realized. Overcoming this barrier requires mechanistic insights that can fuel new directions for pursuit, but scientific investigation of this treatment hypothesis, particularly with regards to trastuzumab, has been complicated by conflicting and confusing data sets, ironclad dogma, and mechanistic conclusions that have repeatedly failed to translate clinically. We are now approaching a point of convergence regarding the challenges and resiliency in this tumor driver, and I will provide here a review and opinion to inform where we currently stand with this treatment hypothesis and where the future potential lies.
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Affiliation(s)
- Mark M Moasser
- University of California, San Francisco, San Francisco, CA, United States
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18
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Wollman AJM, Fournier C, Llorente-Garcia I, Harriman O, Payne-Dwyer AL, Shashkova S, Zhou P, Liu TC, Ouaret D, Wilding J, Kusumi A, Bodmer W, Leake MC. Critical roles for EGFR and EGFR-HER2 clusters in EGF binding of SW620 human carcinoma cells. J R Soc Interface 2022; 19:20220088. [PMID: 35612280 PMCID: PMC9131850 DOI: 10.1098/rsif.2022.0088] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Epidermal growth factor (EGF) signalling regulates normal epithelial and other cell growth, with EGF receptor (EGFR) overexpression reported in many cancers. However, the role of EGFR clusters in cancer and their dependence on EGF binding is unclear. We present novel single-molecule total internal reflection fluorescence microscopy of (i) EGF and EGFR in living cancer cells, (ii) the action of anti-cancer drugs that separately target EGFR and human EGFR2 (HER2) on these cells and (iii) EGFR–HER2 interactions. We selected human epithelial SW620 carcinoma cells for their low level of native EGFR expression, for stable transfection with fluorescent protein labelled EGFR, and imaged these using single-molecule localization microscopy to quantify receptor architectures and dynamics upon EGF binding. Prior to EGF binding, we observe pre-formed EGFR clusters. Unexpectedly, clusters likely contain both EGFR and HER2, consistent with co-diffusion of EGFR and HER2 observed in a different model CHO-K1 cell line, whose stoichiometry increases following EGF binding. We observe a mean EGFR : EGF stoichiometry of approximately 4 : 1 for plasma membrane-colocalized EGFR–EGF that we can explain using novel time-dependent kinetics modelling, indicating preferential ligand binding to monomers. Our results may inform future cancer drug developments.
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Affiliation(s)
- Adam J M Wollman
- Department of Physics, University of York, York, UK.,Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Charlotte Fournier
- Department of Physics, Clarendon Laboratory, University of Oxford, Oxford OX1 3PU, UK.,Science and Technology Group, Okinawa Institute of Science and Technology Graduate University (OIST), 1919 Tancha, Onna-son, Okinawa 904-0495, Japan
| | | | - Oliver Harriman
- Department of Physics, Clarendon Laboratory, University of Oxford, Oxford OX1 3PU, UK
| | | | | | - Peng Zhou
- Membrane Cooperativity Unit, OIST, 1919 Tancha, Onna-son, Okinawa 904-0495, Japan
| | - Ta-Chun Liu
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Djamila Ouaret
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Jenny Wilding
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Akihiro Kusumi
- Membrane Cooperativity Unit, OIST, 1919 Tancha, Onna-son, Okinawa 904-0495, Japan
| | - Walter Bodmer
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Mark C Leake
- Department of Physics, University of York, York, UK.,Department of Biology, University of York, York, UK.,Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
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19
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Johnson KC, Quiroga D, Sudheendra P, Wesolowski R. Treatment of small (T1mic, T1a, and T1b) node-negative HER2+ breast cancer - a review of current evidence for and against the use of anti-HER2 treatment regimens. Expert Rev Anticancer Ther 2022; 22:505-522. [PMID: 35389302 PMCID: PMC9156575 DOI: 10.1080/14737140.2022.2063844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Since the advent of anti-HER2 therapies, evidence surrounding adjuvant treatment of small (T1mic, T1a, and T1b), node-negative, HER2-positive breast cancer (HER2+BC) has remained limited. Practices vary widely between institutions with little known regarding the added benefit of systemic therapy, including cytotoxic chemotherapy and HER2-directed treatments. Our group has set out to perform an extensive review of available literature on this topic. AREAS COVERED In this review, we examined HER2 biology, anti-HER therapies, outcome definitions, and available prospective and retrospective data surrounding the use of adjuvant therapy in those with small, node-negative, HER2+BC. For outcomes, we primarily explored breast cancer-specific survival (BCSS), invasive disease-free survival (iDFS), and overall survival (OS). We also investigated the incidence of adverse events with a particular focus on symptomatic and asymptomatic declines in left ventricular ejection fraction. EXPERT OPINION Retrospective data will likely be the main driver for future treatment decisions. Given what we know, high risk T1b and T1c subgroups derive measurable added benefit from HER2-guided combination therapies but it's not clear whether these benefits outweigh known risks associated with this combination therapy. For tumors ≤0.5cm (T1mic and T1a), treatment remains highly controversial with limited evidence available through retrospective analysis that suggest over-treatment may be occurring.
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Affiliation(s)
- Kai Cc Johnson
- Stefanie Spielman Comprehensive Breast Center, Columbus, OH, USA
| | - Dionisia Quiroga
- Stefanie Spielman Comprehensive Breast Center, Columbus, OH, USA.,Pelotonia Institute for Immuno-Oncology, Division of Medical Oncology, The Ohio State University Comprehensive Cancer Center, Columbus, OH, USA
| | | | - Robert Wesolowski
- Stefanie Spielman Comprehensive Breast Center, Columbus, OH, USA.,Pelotonia Institute for Immuno-Oncology, Division of Medical Oncology, The Ohio State University Comprehensive Cancer Center, Columbus, OH, USA
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20
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Campbell MR, Ruiz-Saenz A, Zhang Y, Peterson E, Steri V, Oeffinger J, Sampang M, Jura N, Moasser MM. Extensive conformational and physical plasticity protects HER2-HER3 tumorigenic signaling. Cell Rep 2022; 38:110285. [PMID: 35108526 PMCID: PMC8865943 DOI: 10.1016/j.celrep.2021.110285] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 08/30/2021] [Accepted: 12/28/2021] [Indexed: 12/13/2022] Open
Abstract
Surface-targeting biotherapeutic agents have been successful in treating HER2-amplified cancers through immunostimulation or chemodelivery but have failed to produce effective inhibitors of constitutive HER2-HER3 signaling. We report an extensive structure-function analysis of this tumor driver, revealing complete uncoupling of intracellular signaling and tumorigenic function from regulation or constraints from their extracellular domains (ECDs). The canonical HER3 ECD conformational changes and exposure of the dimerization interface are nonessential, and the entire ECDs of HER2 and HER3 are redundant for tumorigenic signaling. Restricting the proximation of partner ECDs with bulk and steric clash through extremely disruptive receptor engineering leaves tumorigenic signaling unperturbed. This is likely due to considerable conformational flexibilities across the span of these receptor molecules and substantial undulations in the plane of the plasma membrane, none of which had been foreseen as impediments to targeting strategies. The massive overexpression of HER2 functionally and physically uncouples intracellular signaling from extracellular constraints.
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Affiliation(s)
- Marcia R Campbell
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Ana Ruiz-Saenz
- Departments of Cell Biology & Medical Oncology, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Yuntian Zhang
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Elliott Peterson
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Veronica Steri
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Julie Oeffinger
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Maryjo Sampang
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Natalia Jura
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Mark M Moasser
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94143, USA.
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21
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Wang L, Li C, Li J, Zhang X, Li X, Cui Y, Xia Y, Zhang Y, Mao S, Ji Y, Sheng W, Han X. Liquid-phase scanning electron microscopy for single membrane protein imaging. Biochem Biophys Res Commun 2022; 590:163-168. [PMID: 34979317 DOI: 10.1016/j.bbrc.2021.12.081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 12/22/2021] [Indexed: 11/02/2022]
Abstract
Liquid-phase electron microscopy is highly desirable for observing biological samples in their native liquid state at high resolution. We developed liquid imaging approaches for biological cells using scanning electron microscopy. Novel approaches included scanning transmission electron imaging using a liquid-cell apparatus (LC-STEM), as well as correlative cathodoluminescence and electron microscopy (CCLEM) imaging. LC-STEM enabled imaging at a ∼2 nm resolution and excellent contrast for the precise recognition of localization, distribution, and configuration of individually labeled membrane proteins on the native cells in solution. CCLEM improved the resolution of fluorescent images down to 10 nm. Liquid SEM technologies will bring unique and wide applications to the study of the structure and function of cells and membrane proteins in their near-native states at the monomolecular level.
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Affiliation(s)
- Li Wang
- Beijing Key Laboratory of Microstructure and Property of Solids, Institute of Microstructure and Property of Advanced Materials, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing, 100124, China
| | - Changshuo Li
- Beijing Key Laboratory of Microstructure and Property of Solids, Institute of Microstructure and Property of Advanced Materials, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing, 100124, China
| | - Jintao Li
- Beijing Key Laboratory of Environmental and Viral Oncology, Beijing International Science and Technology, Cooperation Base of Antivirus Drug, College of Life Science and Bioengineering, Beijing University of Technology, Beijing, 100124, China
| | - Xiaofei Zhang
- Beijing Key Laboratory of Microstructure and Property of Solids, Institute of Microstructure and Property of Advanced Materials, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing, 100124, China
| | - Xiaochen Li
- Beijing Key Laboratory of Microstructure and Property of Solids, Institute of Microstructure and Property of Advanced Materials, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing, 100124, China
| | - Yiran Cui
- Beijing Key Laboratory of Microstructure and Property of Solids, Institute of Microstructure and Property of Advanced Materials, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing, 100124, China
| | - Yang Xia
- Beijing Key Laboratory of Environmental and Viral Oncology, Beijing International Science and Technology, Cooperation Base of Antivirus Drug, College of Life Science and Bioengineering, Beijing University of Technology, Beijing, 100124, China
| | - Yinqi Zhang
- Beijing Key Laboratory of Microstructure and Property of Solids, Institute of Microstructure and Property of Advanced Materials, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing, 100124, China
| | - Shengcheng Mao
- Beijing Key Laboratory of Microstructure and Property of Solids, Institute of Microstructure and Property of Advanced Materials, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing, 100124, China
| | - Yuan Ji
- Beijing Key Laboratory of Microstructure and Property of Solids, Institute of Microstructure and Property of Advanced Materials, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing, 100124, China.
| | - Wang Sheng
- Beijing Key Laboratory of Environmental and Viral Oncology, Beijing International Science and Technology, Cooperation Base of Antivirus Drug, College of Life Science and Bioengineering, Beijing University of Technology, Beijing, 100124, China.
| | - Xiaodong Han
- Beijing Key Laboratory of Microstructure and Property of Solids, Institute of Microstructure and Property of Advanced Materials, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing, 100124, China.
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22
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Shipunova VO, Deyev SM. Artificial Scaffold Polypeptides As an Efficient Tool for the Targeted Delivery of Nanostructures In Vitro and In Vivo. Acta Naturae 2022; 14:54-72. [PMID: 35441046 PMCID: PMC9013437 DOI: 10.32607/actanaturae.11545] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 12/20/2021] [Indexed: 12/22/2022] Open
Abstract
The use of traditional tools for the targeted delivery of nanostructures, such as antibodies, transferrin, lectins, or aptamers, often leads to an entire range of undesirable effects. The large size of antibodies often does not allow one to reach the required number of molecules on the surface of nanostructures during modification, and the constant domains of heavy chains, due to their effector functions, can induce phagocytosis. In the recent two decades, targeted polypeptide scaffold molecules of a non-immunoglobulin nature, antibody mimetics, have emerged as much more effective targeting tools. They are small in size (3-20 kDa), possess high affinity (from subnano- to femtomolar binding constants), low immunogenicity, and exceptional thermodynamic stability. These molecules can be effectively produced in bacterial cells, and, using genetic engineering manipulations, it is possible to create multispecific fusion proteins for the targeting of nanoparticles to cells with a given molecular portrait, which makes scaffold polypeptides an optimal tool for theranostics.
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Affiliation(s)
- V. O. Shipunova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, 117997 Russia
| | - S. M. Deyev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, 117997 Russia
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23
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Peckys DB, Gaa D, de Jonge N. Quantification of EGFR-HER2 Heterodimers in HER2-Overexpressing Breast Cancer Cells Using Liquid-Phase Electron Microscopy. Cells 2021; 10:cells10113244. [PMID: 34831465 PMCID: PMC8623301 DOI: 10.3390/cells10113244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 11/10/2021] [Accepted: 11/15/2021] [Indexed: 12/25/2022] Open
Abstract
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.
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Affiliation(s)
- Diana B. Peckys
- Clinic of Operative Dentistry, Periodontology and Preventive Dentistry, University Hospital, Saarland University, 66421 Homburg, Germany;
| | - Daniel Gaa
- INM—Leibniz Institute for New Materials, 66123 Saarbrücken, Germany;
| | - Niels de Jonge
- INM—Leibniz Institute for New Materials, 66123 Saarbrücken, Germany;
- Department of Physics, Saarland University, 66123 Saarbrücken, Germany
- Correspondence:
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24
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Stelate A, Tihlaříková E, Schwarzerová K, Neděla V, Petrášek J. Correlative Light-Environmental Scanning Electron Microscopy of Plasma Membrane Efflux Carriers of Plant Hormone Auxin. Biomolecules 2021; 11:1407. [PMID: 34680040 PMCID: PMC8533460 DOI: 10.3390/biom11101407] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/21/2021] [Accepted: 09/22/2021] [Indexed: 12/17/2022] Open
Abstract
Fluorescence light microscopy provided convincing evidence for the domain organization of plant plasma membrane (PM) proteins. Both peripheral and integral PM proteins show an inhomogeneous distribution within the PM. However, the size of PM nanodomains and protein clusters is too small to accurately determine their dimensions and nano-organization using routine confocal fluorescence microscopy and super-resolution methods. To overcome this limitation, we have developed a novel correlative light electron microscopy method (CLEM) using total internal reflection fluorescence microscopy (TIRFM) and advanced environmental scanning electron microscopy (A-ESEM). Using this technique, we determined the number of auxin efflux carriers from the PINFORMED (PIN) family (NtPIN3b-GFP) within PM nanodomains of tobacco cell PM ghosts. Protoplasts were attached to coverslips and immunostained with anti-GFP primary antibody and secondary antibody conjugated to fluorochrome and gold nanoparticles. After imaging the nanodomains within the PM with TIRFM, the samples were imaged with A-ESEM without further processing, and quantification of the average number of molecules within the nanodomain was performed. Without requiring any post-fixation and coating procedures, this method allows to study details of the organization of auxin carriers and other plant PM proteins.
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Affiliation(s)
- Ayoub Stelate
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 44 Prague 2, Czech Republic; (A.S.); (K.S.)
| | - Eva Tihlaříková
- Institute of Scientific Instruments, Academy of Sciences of the Czech Republic, Královopolská 147, 612 64 Brno, Czech Republic; (E.T.); (V.N.)
| | - Kateřina Schwarzerová
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 44 Prague 2, Czech Republic; (A.S.); (K.S.)
| | - Vilém Neděla
- Institute of Scientific Instruments, Academy of Sciences of the Czech Republic, Královopolská 147, 612 64 Brno, Czech Republic; (E.T.); (V.N.)
| | - Jan Petrášek
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 44 Prague 2, Czech Republic; (A.S.); (K.S.)
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25
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Guide to controlling the electron dose to improve low-dose imaging of sensitive samples. Micron 2021; 145:103058. [DOI: 10.1016/j.micron.2021.103058] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 03/14/2021] [Accepted: 03/14/2021] [Indexed: 11/22/2022]
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26
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Kubota R, Tanaka W, Hamachi I. Microscopic Imaging Techniques for Molecular Assemblies: Electron, Atomic Force, and Confocal Microscopies. Chem Rev 2021; 121:14281-14347. [DOI: 10.1021/acs.chemrev.0c01334] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Ryou Kubota
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Wataru Tanaka
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Itaru Hamachi
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
- JST-ERATO, Hamachi Innovative Molecular Technology for Neuroscience, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8530, Japan
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27
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Supra-Molecular Assemblies of ORAI1 at Rest Precede Local Accumulation into Puncta after Activation. Int J Mol Sci 2021; 22:ijms22020799. [PMID: 33466866 PMCID: PMC7831003 DOI: 10.3390/ijms22020799] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/04/2021] [Accepted: 01/12/2021] [Indexed: 12/13/2022] Open
Abstract
The Ca2+ selective channel ORAI1 and endoplasmic reticulum (ER)-resident STIM proteins form the core of the channel complex mediating store operated Ca2+ entry (SOCE). Using liquid phase electron microscopy (LPEM), the distribution of ORAI1 proteins was examined at rest and after SOCE-activation at nanoscale resolution. The analysis of over seven hundred thousand ORAI1 positions revealed a number of ORAI1 channels had formed STIM-independent distinct supra-molecular clusters. Upon SOCE activation and in the presence of STIM proteins, a fraction of ORAI1 assembled in micron-sized two-dimensional structures, such as the known puncta at the ER plasma membrane contact zones, but also in divergent structures such as strands, and ring-like shapes. Our results thus question the hypothesis that stochastically migrating single ORAI1 channels are trapped at regions containing activated STIM, and we propose instead that supra-molecular ORAI1 clusters fulfill an amplifying function for creating dense ORAI1 accumulations upon SOCE-activation.
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28
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Ambrosetti E, Bernardinelli G, Hoffecker I, Hartmanis L, Kiriako G, de Marco A, Sandberg R, Högberg B, Teixeira AI. A DNA-nanoassembly-based approach to map membrane protein nanoenvironments. NATURE NANOTECHNOLOGY 2021; 16:85-95. [PMID: 33139936 DOI: 10.1038/s41565-020-00785-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 09/21/2020] [Indexed: 06/11/2023]
Abstract
Most proteins at the plasma membrane are not uniformly distributed but localize to dynamic domains of nanoscale dimensions. To investigate their functional relevance, there is a need for methods that enable comprehensive analysis of the compositions and spatial organizations of membrane protein nanodomains in cell populations. Here we describe the development of a non-microscopy-based method for ensemble analysis of membrane protein nanodomains. The method, termed nanoscale deciphering of membrane protein nanodomains (NanoDeep), is based on the use of DNA nanoassemblies to translate membrane protein organization information into a DNA sequencing readout. Using NanoDeep, we characterized the nanoenvironments of Her2, a membrane receptor of critical relevance in cancer. Importantly, we were able to modulate by design the inventory of proteins analysed by NanoDeep. NanoDeep has the potential to provide new insights into the roles of the composition and spatial organization of protein nanoenvironments in the regulation of membrane protein function.
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Affiliation(s)
- Elena Ambrosetti
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Giulio Bernardinelli
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Ian Hoffecker
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Leonard Hartmanis
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Georges Kiriako
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Ario de Marco
- Laboratory for Environmental and Life Sciences, University of Nova Gorica, Nova Gorica, Slovenia
| | - Rickard Sandberg
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Björn Högberg
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Ana I Teixeira
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
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EGFR Expression in HER2-Driven Breast Cancer Cells. Int J Mol Sci 2020; 21:ijms21239008. [PMID: 33260837 PMCID: PMC7729501 DOI: 10.3390/ijms21239008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 11/20/2020] [Accepted: 11/24/2020] [Indexed: 12/12/2022] Open
Abstract
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.
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30
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Peckys DB, Quint C, Jonge ND. Determining the Efficiency of Single Molecule Quantum Dot Labeling of HER2 in Breast Cancer Cells. NANO LETTERS 2020; 20:7948-7955. [PMID: 33034459 DOI: 10.1021/acs.nanolett.0c02644] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Quantum dots exhibit unique properties compared to other fluorophores, such as bright fluorescence and lack of photobleaching, resulting in their widespread utilization as fluorescent protein labels in the life sciences. However, their application is restricted to relative quantifications due to lacking knowledge about the labeling efficiency. We here present a strategy for determining the labeling efficiency of quantum dot labeling of HER2 in overexpressing breast cancer cells. Correlative light- and liquid-phase electron microscopy of whole cells was used to convert fluorescence intensities into the underlying molecular densities of the quantum dots. The labeling procedure with small affinity proteins was optimized yielding a maximal labeling efficiency of 83%, which was applicable to the high amount of ∼1.5 × 106 HER2 per cell. With the labeling efficiency known, it is now possible to derive the absolute protein expression levels in the plasma membrane and its variation within a cell and between cells.
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Affiliation(s)
- Diana B Peckys
- Molecular Biophysics, Center for Integrative Physiology and Molecular Medicine, Saarland University, 66421 Homburg, Germany
| | - Cedric Quint
- Department of Physics, Saarland University, 66123 Saarbrücken, Germany
| | - Niels de Jonge
- Department of Physics, Saarland University, 66123 Saarbrücken, Germany
- INM - Leibniz Institute for New Materials, 66123 Saarbrücken, Germany
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31
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Investigations of EGFR configurations on tumor cell surface by high-resolution electron microscopy. Biochem Biophys Res Commun 2020; 532:179-184. [PMID: 32854945 DOI: 10.1016/j.bbrc.2020.07.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 07/06/2020] [Indexed: 01/11/2023]
Abstract
Epidermal growth factor receptor (EGFR) is an important target for tumor therapy in various tumors. The current understanding of EGFR conformations on the cell surface is based on X-ray structural data, molecular dynamic simulations, and fluorescence-localization imaging. Using scanning electron microscope (SEM) and transmission electron microscope (TEM) with the resolution at sub-nanometers, we successfully recognized individual molecules of EGFRs and their assembly details on the surface of triple-negative breast cancer (TNBC) upon one-to-one labeling by Au nanoparticles. Based on our results, we have proposed the possible configurations, structural models, and conformational transitions of EGFR oligomers. Our study shows that the high-resolution electron imaging is an invaluable tool to provide direct evidence of EGFR configuration on tumor cell surfaces, and may play a pivotal role in further understanding of EGFR-associated signaling and tumor therapy.
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32
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Dahmke IN, Trampert P, Weinberg F, Mostajeran Z, Lautenschläger F, de Jonge N. Correlative Fluorescence- and Electron Microscopy of Whole Breast Cancer Cells Reveals Different Distribution of ErbB2 Dependent on Underlying Actin. Front Cell Dev Biol 2020; 8:521. [PMID: 32714928 PMCID: PMC7344305 DOI: 10.3389/fcell.2020.00521] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 06/02/2020] [Indexed: 12/26/2022] Open
Abstract
Epidermal growth factor receptor 2 (ErbB2) is found overexpressed in several cancers, such as gastric, and breast cancer, and is, therefore, an important therapeutic target. ErbB2 plays a central role in cancer cell invasiveness, and is associated with cytoskeletal reorganization. In order to study the spatial correlation of single ErbB2 proteins and actin filaments, we applied correlative fluorescence microscopy (FM), and scanning transmission electron microscopy (STEM) to image specifically labeled SKBR3 breast cancer cells. The breast cancer cells were grown on microchips, transformed to express an actin-green fluorescent protein (GFP) fusion protein, and labeled with quantum dot (QD) nanoparticles attached to specific anti-ErbB2 Affibodies. FM was performed to identify cellular regions with spatially correlated actin and ErbB2 expression. For STEM of the intact plasma membrane of whole cells, the cells were fixed and covered with graphene. Spatial distribution patterns of ErbB2 in the actin rich ruffled membrane regions were examined, and compared to adjacent actin-low regions of the same cell, revealing an association of putative signaling active ErbB2 homodimers with actin-rich regions. ErbB2 homodimers were found absent from actin-low membrane regions, as well as after treatment of cells with Cytochalasin D, which breaks up larger actin filaments. In both latter data sets, a significant inter-label distance of 36 nm was identified, possibly indicating an indirect attachment to helical actin filaments via the formation of heterodimers of ErbB2 with epidermal growth factor receptor (EGFR). The possible attachment to actin filaments was further explored by identifying linear QD-chains in actin-rich regions, which also showed an inter-label distance of 36 nm.
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Affiliation(s)
| | - Patrick Trampert
- German Research Center for Artificial Intelligence, Saarbrücken, Germany
| | | | | | - Franziska Lautenschläger
- INM – Leibniz Institute for New Materials, Saarbrücken, Germany
- Department of Physics, Saarland University, Saarbrücken, Germany
| | - Niels de Jonge
- INM – Leibniz Institute for New Materials, Saarbrücken, Germany
- Department of Physics, Saarland University, Saarbrücken, Germany
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33
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Microscopic and nanoscopic protein imaging by SIMS and helium ion microscopy. Biointerphases 2020; 15:038501. [PMID: 32590901 DOI: 10.1116/6.0000220] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Single protein imaging and understanding their interactions are of paramount importance to understand the life phenomena. Recently reported multiplex protein SIMS imaging methodology using metal-oxide nanoparticle conjugated antibodies can be extended to a single protein imaging methodology using He ion microscopy (HIM). It is proposed here that single protein can be imaged in the microscale and the nanoscale by the complementary use of SIMS and HIM.
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34
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Weinberg F, Han MKL, Dahmke IN, Del Campo A, de Jonge N. Anti-correlation of HER2 and focal adhesion complexes in the plasma membrane. PLoS One 2020; 15:e0234430. [PMID: 32511274 PMCID: PMC7279600 DOI: 10.1371/journal.pone.0234430] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 05/25/2020] [Indexed: 11/18/2022] Open
Abstract
Excess presence of the human epidermal growth factor receptor 2 (HER2) as well as of the focal adhesion protein complexes are associated with increased proliferation, migratory, and invasive behavior of cancer cells. A cross-regulation between HER2 and integrin signaling pathways has been found, but the exact mechanism remains elusive. Here, we investigated whether HER2 colocalizes with focal adhesion complexes on breast cancer cells overexpressing HER2. For this purpose, vinculin or talin green fluorescent protein (GFP) fusion proteins, both key constituents of focal adhesions, were expressed in breast cancer cells. HER2 was either extracellularly or intracellularly labeled with fluorescent quantum dots nanoparticles (QDs). The cell-substrate interface was analyzed at the location of the focal adhesions by means of total internal reflection fluorescent microscopy or correlative fluorescence- and scanning transmission electron microscopy. Expression of HER2 at the cell-substrate interface was only observed upon intracellular labeling, and was heterogeneous with both HER2-enriched and -low regions. In contrast to an expected enrichment of HER2 at focal adhesions, an anti-correlated expression pattern was observed for talin and HER2. Our findings suggest a spatial anti-correlation between HER2 and focal adhesion complexes for adherent cells.
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Affiliation(s)
| | | | | | - Aránzazu Del Campo
- INM – Leibniz Institute for New Materials, Saarbrücken, Germany
- Department of Chemistry, University of Saarland, Saarbrücken, Germany
| | - Niels de Jonge
- INM – Leibniz Institute for New Materials, Saarbrücken, Germany
- Department of Physics, University of Saarland, Saarbrücken, Germany
- * E-mail:
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35
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Wu H, Friedrich H, Patterson JP, Sommerdijk NAJM, de Jonge N. Liquid-Phase Electron Microscopy for Soft Matter Science and Biology. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2001582. [PMID: 32419161 DOI: 10.1002/adma.202001582] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 04/05/2020] [Accepted: 04/06/2020] [Indexed: 05/20/2023]
Abstract
Innovations in liquid-phase electron microscopy (LP-EM) have made it possible to perform experiments at the optimized conditions needed to examine soft matter. The main obstacle is conducting experiments in such a way that electron beam radiation can be used to obtain answers for scientific questions without changing the structure and (bio)chemical processes in the sample due to the influence of the radiation. By overcoming these experimental difficulties at least partially, LP-EM has evolved into a new microscopy method with nanometer spatial resolution and sub-second temporal resolution for analysis of soft matter in materials science and biology. Both experimental design and applications of LP-EM for soft matter materials science and biological research are reviewed, and a perspective of possible future directions is given.
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Affiliation(s)
- Hanglong Wu
- Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Eindhoven, 5600 MB, The Netherlands
| | - Heiner Friedrich
- Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Eindhoven, 5600 MB, The Netherlands
- Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, 5600 MB, The Netherlands
| | - Joseph P Patterson
- Department of Chemistry, University of California, Irvine, CA, 92697, USA
| | - Nico A J M Sommerdijk
- Department of Biochemistry, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Niels de Jonge
- INM - Leibniz Institute for New Materials, Saarbrücken, 66123, Germany
- Department of Physics, Saarland University, Saarbrücken, 66123, Germany
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36
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Sograte-Idrissi S, Schlichthaerle T, Duque-Afonso CJ, Alevra M, Strauss S, Moser T, Jungmann R, Rizzoli SO, Opazo F. Circumvention of common labelling artefacts using secondary nanobodies. NANOSCALE 2020; 12:10226-10239. [PMID: 32356544 DOI: 10.1039/d0nr00227e] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
A standard procedure to study cellular elements is via immunostaining followed by optical imaging. This methodology typically requires target-specific primary antibodies (1.Abs), which are revealed by secondary antibodies (2.Abs). Unfortunately, the antibody bivalency, polyclonality, and large size can result in a series of artifacts. Alternatively, small, monovalent probes, such as single-domain antibodies (nanobodies) have been suggested to minimize these limitations. The discovery and validation of nanobodies against specific targets are challenging, thus only a minimal amount of them are currently available. Here, we used STED, DNA-PAINT, and light-sheet microscopy, to demonstrate that secondary nanobodies (1) increase localization accuracy compared to 2.Abs; (2) allow direct pre-mixing with 1.Abs before staining, reducing experimental time, and enabling the use of multiple 1.Abs from the same species; (3) penetrate thick tissues more efficiently; and (4) avoid probe-induced clustering of target molecules observed with conventional 2.Abs in living or poorly fixed samples. Altogether, we show how secondary nanobodies are a valuable alternative to 2.Abs.
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Affiliation(s)
- Shama Sograte-Idrissi
- Institute of Neuro- and Sensory Physiology, University Medical Center Göttingen, 37073 Göttingen, Germany. and Center for Biostructural Imaging of Neurodegeneration (BIN), University of Göttingen Medical Center, 37075 Göttingen, Germany and International Max Planck Research School for Molecular Biology, Göttingen, Germany
| | - Thomas Schlichthaerle
- Faculty of Physics and Center for Nanoscience, LMU Munich, 80539, Munich, Germany and Max Planck Institute of Biochemistry, 82152, Martinsried, Germany
| | - Carlos J Duque-Afonso
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37075 Göttingen, Germany and Max Planck Institute for Experimental Medicine, 37075 Göttingen, Germany and Multiscale Bioimaging Cluster of Excellence (MBExC), University of Göttingen, 37075 Göttingen, Germany and University of Göttingen, 37075, Göttingen, Germany
| | - Mihai Alevra
- Institute of Neuro- and Sensory Physiology, University Medical Center Göttingen, 37073 Göttingen, Germany.
| | - Sebastian Strauss
- Faculty of Physics and Center for Nanoscience, LMU Munich, 80539, Munich, Germany and Max Planck Institute of Biochemistry, 82152, Martinsried, Germany
| | - Tobias Moser
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37075 Göttingen, Germany and Max Planck Institute for Experimental Medicine, 37075 Göttingen, Germany and Multiscale Bioimaging Cluster of Excellence (MBExC), University of Göttingen, 37075 Göttingen, Germany and University of Göttingen, 37075, Göttingen, Germany
| | - Ralf Jungmann
- Faculty of Physics and Center for Nanoscience, LMU Munich, 80539, Munich, Germany and Max Planck Institute of Biochemistry, 82152, Martinsried, Germany
| | - Silvio O Rizzoli
- Institute of Neuro- and Sensory Physiology, University Medical Center Göttingen, 37073 Göttingen, Germany. and Center for Biostructural Imaging of Neurodegeneration (BIN), University of Göttingen Medical Center, 37075 Göttingen, Germany and Multiscale Bioimaging Cluster of Excellence (MBExC), University of Göttingen, 37075 Göttingen, Germany
| | - Felipe Opazo
- Institute of Neuro- and Sensory Physiology, University Medical Center Göttingen, 37073 Göttingen, Germany. and Center for Biostructural Imaging of Neurodegeneration (BIN), University of Göttingen Medical Center, 37075 Göttingen, Germany and NanoTag Biotechnologies GmbH, 37079, Göttingen, Germany
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37
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Jun S, Ro HJ, Bharda A, Kim SI, Jeoung D, Jung HS. Advances in Cryo-Correlative Light and Electron Microscopy: Applications for Studying Molecular and Cellular Events. Protein J 2020; 38:609-615. [PMID: 31396855 DOI: 10.1007/s10930-019-09856-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Cryo-correlative light and electron microscopy (Cryo-CLEM) is materializing as a widespread approach amalgamating the advantages of both fluorescence light microscopy (FLM) as well as three dimensional (3D) cryo-electron tomography (cryo-ET) to reveal the ultrastructure of significant target molecules with specific cellular functions. Cryo-CLEM allows imaging of cells by means of fluorescence microscopy exhibiting the location of the destined molecule at high temporal and spatial resolution while cryo-ET is employed to analyze the 3D structure at a molecular resolution in close-to-physiological condition. Present review focuses upon the practical strategies for Cryo-CLEM and recent technical developments that will assist the broad implementation of this technique to investigate and answer questions pertaining to various biological events occurring in the cell.
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Affiliation(s)
- Sangmi Jun
- Drug & Disease Target Team, Korea Basic Science Institute, 162, Yeongudanji-ro, Ochang-eup, Cheongwon-gu, Cheongju-Si, Chungcheongbuk-do, 28119, South Korea. .,Convergent Research Center for Emerging Virus Infection, Korea Research Institute of Chemical Technology, Daejeon, South Korea. .,Bio-Analytical Science, University of Science & Technology, Daejeon, South Korea.
| | - Hyun-Joo Ro
- Drug & Disease Target Team, Korea Basic Science Institute, 162, Yeongudanji-ro, Ochang-eup, Cheongwon-gu, Cheongju-Si, Chungcheongbuk-do, 28119, South Korea.,Convergent Research Center for Emerging Virus Infection, Korea Research Institute of Chemical Technology, Daejeon, South Korea.,Bio-Analytical Science, University of Science & Technology, Daejeon, South Korea
| | - Anahita Bharda
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, 1 Kangwondaehak-gil, Chuncheon-Si, Gangwon-do, 200-701, South Korea
| | - Seung Il Kim
- Drug & Disease Target Team, Korea Basic Science Institute, 162, Yeongudanji-ro, Ochang-eup, Cheongwon-gu, Cheongju-Si, Chungcheongbuk-do, 28119, South Korea.,Convergent Research Center for Emerging Virus Infection, Korea Research Institute of Chemical Technology, Daejeon, South Korea.,Bio-Analytical Science, University of Science & Technology, Daejeon, South Korea
| | - Dooil Jeoung
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, 1 Kangwondaehak-gil, Chuncheon-Si, Gangwon-do, 200-701, South Korea
| | - Hyun Suk Jung
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, 1 Kangwondaehak-gil, Chuncheon-Si, Gangwon-do, 200-701, South Korea.
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38
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Alansary D, Peckys DB, Niemeyer BA, de Jonge N. Detecting single ORAI1 proteins within the plasma membrane reveals higher-order channel complexes. J Cell Sci 2020; 133:jcs.240358. [PMID: 31822631 DOI: 10.1242/jcs.240358] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 12/02/2019] [Indexed: 12/22/2022] Open
Abstract
ORAI1 proteins form highly selective Ca2+ channels in the plasma membrane. Crystallographic data point towards a hexameric stoichiometry of ORAI1 channels, whereas optical methods postulated ORAI1 channels to reside as dimers at rest, and other data suggests that they have a tetrameric configuration. Here, liquid-phase scanning transmission electron microscopy (STEM) and quantum dot (QD) labeling was utilized to study the conformation of ORAI1 proteins at rest. To address the question of whether ORAI1 was present as a dimer, experiments were designed using single ORAI1 monomers and covalently linked ORAI1 dimers with either one or two label-binding positions. The microscopic data was statistically analyzed via the pair correlation function. Label pairs were found in all cases, even for concatenated dimers with one label-binding position, which is only possible if a significant fraction of ORAI1 was assembled in larger order oligomers than dimers, binding at least two QDs. This interpretation of the data was consistent with Blue Native PAGE analysis showing that ORAI1 is mainly present as a complex of an apparent molecular mass larger than that calculated for a dimer.
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Affiliation(s)
- Dalia Alansary
- Molecular Biophysics, University of Saarland, Center for Integrative Physiology and Molecular Medicine, 66421 Homburg/Saar, Germany
| | - Diana B Peckys
- Molecular Biophysics, University of Saarland, Center for Integrative Physiology and Molecular Medicine, 66421 Homburg/Saar, Germany
| | - Barbara A Niemeyer
- Molecular Biophysics, University of Saarland, Center for Integrative Physiology and Molecular Medicine, 66421 Homburg/Saar, Germany
| | - Niels de Jonge
- INM - Leibniz Institute for New Materials, 66123 Saarbrücken, Germany .,Department of Physics, University of Saarland, 66123 Saarbrücken, Germany
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39
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Smith JW, Chen Q. Liquid-phase electron microscopy imaging of cellular and biomolecular systems. J Mater Chem B 2020; 8:8490-8506. [DOI: 10.1039/d0tb01300e] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Liquid-phase electron microscopy, a new method for real-time nanoscopic imaging in liquid, makes it possible to study cells or biomolecules with a singular combination of spatial and temporal resolution. We review the state of the art in biological research in this growing and promising field.
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Affiliation(s)
- John W. Smith
- Department of Materials Science and Engineering, University of Illinois at Urbana–Champaign
- Urbana
- USA
| | - Qian Chen
- Department of Materials Science and Engineering, University of Illinois at Urbana–Champaign
- Urbana
- USA
- Department of Chemistry
- University of Illinois at Urbana–Champaign
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40
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Pu S, Gong C, Robertson AW. Liquid cell transmission electron microscopy and its applications. ROYAL SOCIETY OPEN SCIENCE 2020; 7:191204. [PMID: 32218950 PMCID: PMC7029903 DOI: 10.1098/rsos.191204] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 11/19/2019] [Indexed: 06/10/2023]
Abstract
Transmission electron microscopy (TEM) has long been an essential tool for understanding the structure of materials. Over the past couple of decades, this venerable technique has undergone a number of revolutions, such as the development of aberration correction for atomic level imaging, the realization of cryogenic TEM for imaging biological specimens, and new instrumentation permitting the observation of dynamic systems in situ. Research in the latter has rapidly accelerated in recent years, based on a silicon-chip architecture that permits a versatile array of experiments to be performed under the high vacuum of the TEM. Of particular interest is using these silicon chips to enclose fluids safely inside the TEM, allowing us to observe liquid dynamics at the nanoscale. In situ imaging of liquid phase reactions under TEM can greatly enhance our understanding of fundamental processes in fields from electrochemistry to cell biology. Here, we review how in situ TEM experiments of liquids can be performed, with a particular focus on microchip-encapsulated liquid cell TEM. We will cover the basics of the technique, and its strengths and weaknesses with respect to related in situ TEM methods for characterizing liquid systems. We will show how this technique has provided unique insights into nanomaterial synthesis and manipulation, battery science and biological cells. A discussion on the main challenges of the technique, and potential means to mitigate and overcome them, will also be presented.
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41
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Bharda AV, Jung HS. Liquid electron microscopy: then, now and future. Appl Microsc 2019; 49:9. [PMID: 33580443 PMCID: PMC7809579 DOI: 10.1186/s42649-019-0011-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 09/25/2019] [Indexed: 11/10/2022] Open
Abstract
Contemporary microscopic imaging at near-atomic resolution of diverse embodiments in liquid environment has gained keen interest. In particular, Electron Microscopy (EM) can provide comprehensive framework on the structural and functional characterization of samples in liquid phase. In the past few decades, liquid based electron microscopic modalities have developed tremendously to provide insights into various backgrounds like biological, chemical, nanoparticle and material researches. It serves to be a promising analytical tool in deciphering unique insights from solvated systems. Here, the basics of liquid electron microscopy with few examples of its applications are summarized in brief. The technical developments made so far and its preference over other approaches is shortly presented. Finally, the experimental limitations and an outlook on the future technical advancement for liquid EM have been discussed.
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Affiliation(s)
- Anahita Vispi Bharda
- Division of Chemistry and Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon-si, Gangwon-do, 24341, South Korea
| | - Hyun Suk Jung
- Division of Chemistry and Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon-si, Gangwon-do, 24341, South Korea.
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42
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Mathematical modeling of drug-induced receptor internalization in the HER2-positive SKBR3 breast cancer cell-line. Sci Rep 2019; 9:12709. [PMID: 31481718 PMCID: PMC6722142 DOI: 10.1038/s41598-019-49019-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 08/19/2019] [Indexed: 12/22/2022] Open
Abstract
About 20% of breast cancer tumors over-express the HER2 receptor. Trastuzumab, an approved drug to treat this type of breast cancer, is a monoclonal antibody directly binding at the HER2 receptor and ultimately inhibiting cancer cell growth. The goal of our study was to understand the early impact of trastuzumab on HER2 internalization and recycling in the HER2-overexpressing breast cancer cell line SKBR3. To this end, fluorescence microscopy, monitoring the amount of HER2 expression in the plasma membrane, was combined with mathematical modeling to derive the flux of HER2 receptors from and to the membrane. We constructed a dynamic multi-compartment model based on ordinary differential equations. To account for cancer cell heterogeneity, a first, dynamic model was expanded to a second model including two distinct cell phenotypes, with implications for different conformational states of HER2, i.e. monomeric or homodimeric. Our mathematical model shows that the hypothesis of fast constitutive HER2 recycling back to the plasma membrane does not match the experimental data. It conclusively describes the experimental observation that trastuzumab induces sustained receptor internalization in cells with membrane ruffles. It is also concluded that for rare, non-ruffled (flat) cells, HER2 internalization occurs three orders of magnitude slower than for the bulk, ruffled cell population.
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43
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Peckys DB, Hirsch D, Gaiser T, de Jonge N. Visualisation of HER2 homodimers in single cells from HER2 overexpressing primary formalin fixed paraffin embedded tumour tissue. Mol Med 2019; 25:42. [PMID: 31455202 PMCID: PMC6712713 DOI: 10.1186/s10020-019-0108-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 07/31/2019] [Indexed: 12/11/2022] Open
Abstract
Background HER2 is considered as one of the most important, predictive biomarkers in oncology. The diagnosis of HER2 positive cancer types such as breast- and gastric cancer is usually based on immunohistochemical HER2 staining of tumour tissue. However, the current immunohistochemical methods do not provide localized information about HER2’s functional state. In order to generate signals leading to cell growth and proliferation, the receptor spontaneously forms homodimers, a process that can differ between individual cancer cells. Materials and methods HER2 overexpressing tumour cells were dissociated from formalin-fixed paraffin-embedded (FFPE) patient’s biopsy sections, subjected to a heat-induced antigen retrieval procedure, and immobilized on microchips. HER2 was specifically labelled via a two-step protocol involving the incubation with an Affibody-biotin compound followed by the binding of a streptavidin coated quantum dot (QD) nanoparticle. Cells with membrane bound HER2 were identified using fluorescence microscopy, coated with graphene to preserve their hydrated state, and subsequently examined by scanning transmission electron microscopy (STEM) to obtain the locations at the single molecule level. Label position data was statistically analysed via the pair correlation function, yielding information about the presence of HER2 homodimers. Results Tumour cells from two biopsies, scored HER2 3+, and a HER2 negative control sample were examined. The specific labelling protocol was first tested for a sectioned tissue sample of HER2-overexpressing tumour. Subsequently, a protocol was optimized to study HER2 homodimerization in single cells dissociated from the tissue section. Electron microscopy data showed membrane bound HER2 in average densities of 201–689 proteins/μm2. An automated, statistical analysis of well over 200,000 of measured protein positions revealed the presence of HER2 homodimers in 33 and 55% of the analysed images for patient 1 and 2, respectively. Conclusions We introduced an electron microscopy method capable of measuring the positions of individually labelled HER2 proteins in patient tumour cells from which information about the functional status of the receptor was derived. This method could take HER2 testing a step further by examining HER2 homodimerization directly out of tumour tissue and may become important for adjusting a personalized antibody-based drug therapy. Electronic supplementary material The online version of this article (10.1186/s10020-019-0108-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Diana B Peckys
- Department of Biophysics, Saarland University, Homburg, Germany
| | - Daniela Hirsch
- Institute for Pathology, University Medical Center Mannheim, Ruprecht-Karls University of Heidelberg, Mannheim, Germany
| | - Timo Gaiser
- Institute for Pathology, University Medical Center Mannheim, Ruprecht-Karls University of Heidelberg, Mannheim, Germany
| | - Niels de Jonge
- INM - Leibniz Institute for New Materials, Campus D2-2, 66123, Saarbrücken, Germany. .,Department of Physics, Saarland University, Saarbrücken, Germany.
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44
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Functional link between plasma membrane spatiotemporal dynamics, cancer biology, and dietary membrane-altering agents. Cancer Metastasis Rev 2019; 37:519-544. [PMID: 29860560 DOI: 10.1007/s10555-018-9733-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The cell plasma membrane serves as a nexus integrating extra- and intracellular components, which together enable many of the fundamental cellular signaling processes that sustain life. In order to perform this key function, plasma membrane components assemble into well-defined domains exhibiting distinct biochemical and biophysical properties that modulate various signaling events. Dysregulation of these highly dynamic membrane domains can promote oncogenic signaling. Recently, it has been demonstrated that select membrane-targeted dietary bioactives (MTDBs) have the ability to remodel plasma membrane domains and subsequently reduce cancer risk. In this review, we focus on the importance of plasma membrane domain structural and signaling functionalities as well as how loss of membrane homeostasis can drive aberrant signaling. Additionally, we discuss the intricacies associated with the investigation of these membrane domain features and their associations with cancer biology. Lastly, we describe the current literature focusing on MTDBs, including mechanisms of chemoprevention and therapeutics in order to establish a functional link between these membrane-altering biomolecules, tuning of plasma membrane hierarchal organization, and their implications in cancer prevention.
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45
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He K, Shokuhfar T, Shahbazian-Yassar R. Imaging of soft materials using in situ liquid-cell transmission electron microscopy. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:103001. [PMID: 30524096 DOI: 10.1088/1361-648x/aaf616] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
This review summarizes the breakthroughs in the field of soft material characterization by in situ liquid-cell transmission electron microscopy (TEM). The focus of this review is mostly on soft biological species such as cells, bacteria, viruses, proteins and polymers. The comparison between the two main liquid-cell systems (silicon nitride membranes liquid cell and graphene liquid cell) is also discussed in terms of their spatial resolution and imaging/analytical capabilities. We have showcased how liquid-cell TEM can reveal the structural details of whole cells, enable the chemical probing of proteins, detect the structural conformation of viruses, and monitor the dynamics of polymerization. In addition, the challenges faced by decoupling electron beam effect on beam-sensitive soft materials are discussed. At the end, future perspectives of in situ liquid-cell TEM studies of soft materials are outlined.
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Affiliation(s)
- Kun He
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, IL 60607, United States of America
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46
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Murakami A, Maekawa M, Kawai K, Nakayama J, Araki N, Semba K, Taguchi T, Kamei Y, Takada Y, Higashiyama S. Cullin-3/KCTD10 E3 complex is essential for Rac1 activation through RhoB degradation in human epidermal growth factor receptor 2-positive breast cancer cells. Cancer Sci 2019; 110:650-661. [PMID: 30515933 PMCID: PMC6361568 DOI: 10.1111/cas.13899] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 11/23/2018] [Accepted: 11/26/2018] [Indexed: 01/01/2023] Open
Abstract
Rho GTPase Rac1 is a central regulator of F‐actin organization and signal transduction to control plasma membrane dynamics and cell proliferation. Dysregulated Rac1 activity is often observed in various cancers including breast cancer and is suggested to be critical for malignancy. Here, we showed that the ubiquitin E3 ligase complex Cullin‐3 (CUL3)/KCTD10 is essential for epidermal growth factor (EGF)‐induced/human epidermal growth factor receptor 2 (HER2)‐dependent Rac1 activation in HER2‐positive breast cancer cells. EGF‐induced dorsal membrane ruffle formation and cell proliferation that depends on both Rac1 and HER2 were suppressed in CUL3‐ or KCTD10‐depleted cells. Mechanistically, CUL3/KCTD10 ubiquitinated RhoB for degradation, another Rho GTPase that inhibits Rac1 activation at the plasma membrane by suppressing endosome‐to‐plasma membrane traffic of Rac1. In HER2‐positive breast cancers, high expression of Rac1 mRNA significantly correlated with poor prognosis of the patients. This study shows that this novel molecular axis (CUL3/KCTD10/RhoB) positively regulates the activity of Rac1 in HER2‐positive breast cancers, and our findings may lead to new treatment options for HER2‐ and Rac1‐positive breast cancers.
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Affiliation(s)
- Akari Murakami
- Department of Hepato-Biliary-Pancreatic Surgery and Breast Surgery, Ehime University Graduate School of Medicine, Toon, Japan.,Department of Biochemistry and Molecular Genetics, Ehime University Graduate School of Medicine, Toon, Japan
| | - Masashi Maekawa
- Department of Biochemistry and Molecular Genetics, Ehime University Graduate School of Medicine, Toon, Japan.,Division of Cell Growth and Tumor Regulation, Proteo-Science Center, Ehime University, Toon, Japan
| | - Katsuhisa Kawai
- Department of Histology and Cell Biology, School of Medicine, Kagawa University, Miki, Japan
| | - Jun Nakayama
- Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Shinjuku-ku, Japan
| | - Nobukazu Araki
- Department of Histology and Cell Biology, School of Medicine, Kagawa University, Miki, Japan
| | - Kentaro Semba
- Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Shinjuku-ku, Japan
| | - Tomohiko Taguchi
- Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - Yoshiaki Kamei
- Department of Hepato-Biliary-Pancreatic Surgery and Breast Surgery, Ehime University Graduate School of Medicine, Toon, Japan
| | - Yasutsugu Takada
- Department of Hepato-Biliary-Pancreatic Surgery and Breast Surgery, Ehime University Graduate School of Medicine, Toon, Japan
| | - Shigeki Higashiyama
- Department of Biochemistry and Molecular Genetics, Ehime University Graduate School of Medicine, Toon, Japan.,Division of Cell Growth and Tumor Regulation, Proteo-Science Center, Ehime University, Toon, Japan
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47
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Wang J, Dai J, Yang X, Yu X, Emory SR, Yong X, Xu J, Mei L, Xie J, Han N, Zhang X, Ruan G. Intracellular targeted delivery of quantum dots with extraordinary performance enabled by a novel nanomaterial design. NANOSCALE 2019; 11:552-567. [PMID: 30543334 DOI: 10.1039/c8nr06191b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Quantum dots (QDs) have emerged as a major class of fluorescent probes with unique optical properties, but applying QDs for imaging specific intracellular entities in live cells has been hindered by the poor performance of targeted intracellular delivery of QDs due to various cellular transport barriers. We describe a novel QD nanoprobe design, which is termed a cosolvent-bare hydrophobic QD-biomolecule (cS-bQD-BM, or 'SDot' for short), combining a cosolvent, a bare hydrophobic nanoparticle surface, ultrasmall size and biomolecular function. SDots show extraordinary intracellular targeting performance with the nucleus as the model target, including near-perfect specificity, excellent efficiency and reproducibility, high-throughput ability, minimal toxicity, and ease of operation, as well as superb optical properties and colloidal stability. We introduce integrated single-particle tracking and pair-correlation function analysis of a spinning-disk confocal microscope platform (iSPT-pCF-SDCM) to study SDot's cellular transport. Endocytosed SDots can undergo a highly potent and noninvasive process of vesicle escape, yielding complete vesicle escape with no serious vesicle disruption. We exploit SDots' unprecedented ability to overcome cellular transport barriers to enhance drug and macromolecule delivery.
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Affiliation(s)
- Jun Wang
- Department of Biomedical Engineering, College of Engineering and Applied Sciences, Nanjing University, China.
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48
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Lansky Z, Mutsafi Y, Houben L, Ilani T, Armony G, Wolf SG, Fass D. 3D mapping of native extracellular matrix reveals cellular responses to the microenvironment. JOURNAL OF STRUCTURAL BIOLOGY-X 2019; 1:100002. [PMID: 32055794 PMCID: PMC7001979 DOI: 10.1016/j.yjsbx.2018.100002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 11/23/2018] [Accepted: 12/07/2018] [Indexed: 01/23/2023]
Abstract
Cells and extracellular matrix (ECM) are mutually interdependent: cells guide self-assembly of ECM precursors, and the resulting ECM architecture supports and instructs cells. Though bidirectional signaling between ECM and cells is fundamental to cell biology, it is challenging to gain high-resolution structural information on cellular responses to the matrix microenvironment. Here we used cryo-scanning transmission electron tomography (CSTET) to reveal the nanometer- to micron-scale organization of major fibroblast ECM components in a native-like context, while simultaneously visualizing internal cell ultrastructure including organelles and cytoskeleton. In addition to extending current models for collagen VI fibril organization, three-dimensional views of thick cell regions and surrounding matrix showed how ECM networks impact the structures and dynamics of intracellular organelles and how cells remodel ECM. Collagen VI and fibronectin were seen to distribute in fundamentally different ways in the cell microenvironment and perform distinct roles in supporting and interacting with cells. This work demonstrates that CSTET provides a new perspective for the study of ECM in cell biology, highlighting labeled extracellular elements against a backdrop of unlabeled but morphologically identifiable cellular features with nanometer resolution detail.
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Affiliation(s)
- Zipora Lansky
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Yael Mutsafi
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Lothar Houben
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - Tal Ilani
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Gad Armony
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Sharon G. Wolf
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - Deborah Fass
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
- Corresponding author.
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49
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Keskin S, de Jonge N. Reduced Radiation Damage in Transmission Electron Microscopy of Proteins in Graphene Liquid Cells. NANO LETTERS 2018; 18:7435-7440. [PMID: 30431282 DOI: 10.1021/acs.nanolett.8b02490] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Liquid-phase electron microscopy (LPEM) is capable of imaging native (unstained) protein structure in liquid, but the achievable spatial resolution is limited by radiation damage. This damaging effect is more pronounced when targeting small molecular features than for larger structures. The matter is even more complicated because the critical dose that a sample can endure before radiation damage not only varies between proteins but also critically depends on the experimental conditions. Here, we examined the effect of the electron beam on the observed protein structure for optimized conditions using a liquid sample enclosure assembled from graphene sheets. It has been shown that graphene can reduce the damaging effect of electrons on biological materials. We used radiation sensitive microtubule proteins and investigated the radiation damage on these structures as a function of the spatial frequencies of the observed features with transmission electron microscopy (TEM). Microtubule samples were also examined using cryo-electron microscopy (cryo-TEM) for comparison. We used an electron flux of 11 ± 1-16 ± 1 e-/Å2s and obtained a series of images from the same sample region. Our results show that graphene-encapsulated microtubules can maintain their structural features of spatial frequencies of up to 0.20 nm-1 (5 nm), reflecting protofilaments for electron densities of up to 7.2 ± 1.4 × 102 e-/Å2, an order of magnitude higher than measured for frozen microtubules in amorphous ice.
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Affiliation(s)
- Sercan Keskin
- Leibniz Institute for New Materials (INM) , Saarbrücken D-66123 , Germany
| | - Niels de Jonge
- Leibniz Institute for New Materials (INM) , Saarbrücken D-66123 , Germany
- Department of Physics , Saarland University , Saarbrücken D-66123 , Germany
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50
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Ando T, Bhamidimarri SP, Brending N, Colin-York H, Collinson L, De Jonge N, de Pablo PJ, Debroye E, Eggeling C, Franck C, Fritzsche M, Gerritsen H, Giepmans BNG, Grunewald K, Hofkens J, Hoogenboom JP, Janssen KPF, Kaufman R, Klumpermann J, Kurniawan N, Kusch J, Liv N, Parekh V, Peckys DB, Rehfeldt F, Reutens DC, Roeffaers MBJ, Salditt T, Schaap IAT, Schwarz US, Verkade P, Vogel MW, Wagner R, Winterhalter M, Yuan H, Zifarelli G. The 2018 correlative microscopy techniques roadmap. JOURNAL OF PHYSICS D: APPLIED PHYSICS 2018; 51:443001. [PMID: 30799880 PMCID: PMC6372154 DOI: 10.1088/1361-6463/aad055] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 06/14/2018] [Accepted: 07/01/2018] [Indexed: 05/19/2023]
Abstract
Developments in microscopy have been instrumental to progress in the life sciences, and many new techniques have been introduced and led to new discoveries throughout the last century. A wide and diverse range of methodologies is now available, including electron microscopy, atomic force microscopy, magnetic resonance imaging, small-angle x-ray scattering and multiple super-resolution fluorescence techniques, and each of these methods provides valuable read-outs to meet the demands set by the samples under study. Yet, the investigation of cell development requires a multi-parametric approach to address both the structure and spatio-temporal organization of organelles, and also the transduction of chemical signals and forces involved in cell-cell interactions. Although the microscopy technologies for observing each of these characteristics are well developed, none of them can offer read-out of all characteristics simultaneously, which limits the information content of a measurement. For example, while electron microscopy is able to disclose the structural layout of cells and the macromolecular arrangement of proteins, it cannot directly follow dynamics in living cells. The latter can be achieved with fluorescence microscopy which, however, requires labelling and lacks spatial resolution. A remedy is to combine and correlate different readouts from the same specimen, which opens new avenues to understand structure-function relations in biomedical research. At the same time, such correlative approaches pose new challenges concerning sample preparation, instrument stability, region of interest retrieval, and data analysis. Because the field of correlative microscopy is relatively young, the capabilities of the various approaches have yet to be fully explored, and uncertainties remain when considering the best choice of strategy and workflow for the correlative experiment. With this in mind, the Journal of Physics D: Applied Physics presents a special roadmap on the correlative microscopy techniques, giving a comprehensive overview from various leading scientists in this field, via a collection of multiple short viewpoints.
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Affiliation(s)
- Toshio Ando
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa, Japan
| | | | | | - H Colin-York
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, OX3 9DS Oxford, United Kingdom
| | | | - Niels De Jonge
- INM-Leibniz Institute for New Materials, 66123 Saarbrücken, Germany
- Saarland University, 66123 Saarbrücken, Germany
| | - P J de Pablo
- Dpto. Física de la Materia Condensada Universidad Autónoma de Madrid 28049, Madrid, Spain
- Instituto de Física de la Materia Condensada IFIMAC, Universidad Autónoma de Madrid 28049, Madrid, Spain
| | - Elke Debroye
- KU Leuven, Department of Chemistry, B-3001 Heverlee, Belgium
| | - Christian Eggeling
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, OX3 9DS Oxford, United Kingdom
- Institute of Applied Optics, Friedrich-Schiller University, Jena, Germany
- Leibniz Institute of Photonic Technology (IPHT), Jena, Germany
| | - Christian Franck
- Department of Mechanical Engineering, University of Wisconsin-Madison, 1513 University Ave, Madison, WI 53706, United States of America
| | - Marco Fritzsche
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, OX3 9DS Oxford, United Kingdom
- Kennedy Institute for Rheumatology, University of Oxford, Oxford, United Kingdom
| | - Hans Gerritsen
- Debye Institute, Utrecht University, Utrecht, Netherlands
| | - Ben N G Giepmans
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Kay Grunewald
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
- Centre of Structural Systems Biology Hamburg and University of Hamburg, Hamburg, Germany
- Heinrich-Pette-Institute, Leibniz Institute of Virology, Hamburg, Germany
| | - Johan Hofkens
- KU Leuven, Department of Chemistry, B-3001 Heverlee, Belgium
| | | | | | - Rainer Kaufman
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
- Centre of Structural Systems Biology Hamburg and University of Hamburg, Hamburg, Germany
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Judith Klumpermann
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584CX Utrecht, Netherlands
| | - Nyoman Kurniawan
- Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD 4072, Australia
| | | | - Nalan Liv
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584CX Utrecht, Netherlands
| | - Viha Parekh
- Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Diana B Peckys
- Faculty of Medicine, Saarland University, 66421 Homburg, Germany
| | - Florian Rehfeldt
- University of Göttingen, Third Institute of Physics-Biophysics, 37077 Göttingen, Germany
| | - David C Reutens
- Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD 4072, Australia
| | | | - Tim Salditt
- University of Göttingen, Institute for X-Ray Physics, 37077 Göttingen, Germany
| | - Iwan A T Schaap
- SmarAct GmbH, Schütte-Lanz-Str. 9, D-26135 Oldenburg, Germany
| | - Ulrich S Schwarz
- Institute for Theoretical Physics and BioQuant, Heidelberg University, Heidelberg, Germany
| | - Paul Verkade
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Michael W Vogel
- Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Richard Wagner
- Department of Life Sciences & Chemistry, Jacobs University, Bremen, Germany
| | | | - Haifeng Yuan
- KU Leuven, Department of Chemistry, B-3001 Heverlee, Belgium
| | - Giovanni Zifarelli
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
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