1
|
Phillips TA, Caprettini V, Aggarwal N, Marcotti S, Tetley R, Mao Y, Shaw T, Chiappini C, Parsons M, Cox S. A method for reproducible high-resolution imaging of 3D cancer cell spheroids. J Microsc 2023; 291:30-42. [PMID: 36639864 PMCID: PMC10953429 DOI: 10.1111/jmi.13169] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 01/08/2023] [Accepted: 01/09/2023] [Indexed: 01/15/2023]
Abstract
Multicellular tumour cell spheroids embedded within three-dimensional (3D) hydrogels or extracellular matrices (ECM) are widely used as models to study cancer growth and invasion. Standard methods to embed spheroids in 3D matrices result in random placement in space which limits the use of inverted fluorescence microscopy techniques, and thus the resolution that can be achieved to image molecular detail within the intact spheroid. Here, we leverage UV photolithography to microfabricate PDMS (polydimethylsiloxane) stamps that allow for generation of high-content, reproducible well-like structures in multiple different imaging chambers. Addition of multicellular tumour spheroids into stamped collagen structures allows for precise positioning of spheroids in 3D space for reproducible high-/super-resolution imaging. Embedded spheroids can be imaged live or fixed and are amenable to immunostaining, allowing for greater flexibility of experimental approaches. We describe the use of these spheroid imaging chambers to analyse cell invasion, cell-ECM interaction, ECM alignment, force-dependent intracellular protein dynamics and extension of fine actin-based protrusions with a variety of commonly used inverted microscope platforms. This method enables reproducible, high-/super-resolution live imaging of multiple tumour spheroids, that can be potentially extended to visualise organoids and other more complex 3D in vitro systems.
Collapse
Affiliation(s)
- Thomas A. Phillips
- Randall Centre for Cell and Molecular BiophysicsKing's College LondonLondonUK
| | - Valeria Caprettini
- Centre for Craniofacial & Regenerative BiologyKing's College LondonLondonUK
| | - Nandini Aggarwal
- Randall Centre for Cell and Molecular BiophysicsKing's College LondonLondonUK
- Department of Inflammation BiologySchool of Immunology & Microbial SciencesKing's College LondonLondonUK
| | - Stefania Marcotti
- Randall Centre for Cell and Molecular BiophysicsKing's College LondonLondonUK
| | - Rob Tetley
- Laboratory for Molecular Cell Biology and Institute for the Physics of Living SystemsUniversity College LondonLondonUK
| | - Yanlan Mao
- Laboratory for Molecular Cell Biology and Institute for the Physics of Living SystemsUniversity College LondonLondonUK
| | - Tanya Shaw
- Department of Inflammation BiologySchool of Immunology & Microbial SciencesKing's College LondonLondonUK
| | - Ciro Chiappini
- Centre for Craniofacial & Regenerative BiologyKing's College LondonLondonUK
| | - Maddy Parsons
- Randall Centre for Cell and Molecular BiophysicsKing's College LondonLondonUK
| | - Susan Cox
- Randall Centre for Cell and Molecular BiophysicsKing's College LondonLondonUK
| |
Collapse
|
2
|
The Chorioallantoic Membrane Xenograft Assay as a Reliable Model for Investigating the Biology of Breast Cancer. Cancers (Basel) 2023; 15:cancers15061704. [PMID: 36980588 PMCID: PMC10046776 DOI: 10.3390/cancers15061704] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/06/2023] [Accepted: 03/07/2023] [Indexed: 03/17/2023] Open
Abstract
The chorioallantoic membrane (CAM) assay is an alternative in vivo model that allows for minimally invasive research of cancer biology. Using the CAM assay, we investigated phenotypical and functional characteristics (tumor grade, mitosis rate, tumor budding, hormone receptor (HR) and HER2 status, Ki-67 proliferation index) of two breast cancer cell lines, MCF-7 and MDA-MB-231, which resemble the HR+ (luminal) and triple-negative breast cancer (TNBC) subgroups, respectively. Moreover, the CAM results were directly compared with murine MCF-7- and MDA-MB-231-derived xenografts and human patient TNBC tissue. Known phenotypical and biological features of the aggressive triple-negative breast cancer cell line (MDA-MB-231) were confirmed in the CAM assay, and mouse xenografts. Furthermore, the histomorphological and immunohistochemical variables assessed in the CAM model were similar to those in human patient tumor tissue. Given the confirmation of the classical biological and growth properties of breast cancer cell lines in the CAM model, we suggest this in vivo model to be a reliable alternative test system for breast cancer research to reduce murine animal experiments.
Collapse
|
3
|
Brown HM, Juanes MA. Automated Quantitative Analysis of Shape Features in Human Epithelial Monolayers and Spheroids Generated from Colorectal Cancer Cells. Methods Mol Biol 2023; 2650:261-271. [PMID: 37310638 DOI: 10.1007/978-1-0716-3076-1_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Advancements in microscopy techniques permit us to acquire endless datasets of images. A major bottleneck in cell imaging is how to analyze petabytes of data in an effective, reliable, objective, and effortless way. Quantitative imaging is becoming crucial to disentangle the complexity of many biological and pathological processes. For instance, cell shape is a summary readout of a myriad of cellular processes. Changes in cell shape use to reflect changes in growth, migration mode (including speed and persistence), differentiation stage, apoptosis, or gene expression, serving to predict health or disease. However, in certain contexts, e.g., tissues or tumors, cells are tightly packed together, and measurement of individual cellular shapes can be challenging and laborious. Bioinformatics solutions like automated computational image methods provide a blind and efficient analysis of large image datasets. Here we describe a detailed and friendly step-by-step protocol to extract various cellular shape parameters quickly and accurately from colorectal cancer cells forming either monolayers or spheroids. We envision those similar settings could be extended to other cell lines, colorectal and beyond, either label/unlabeled or in 2D/3D environments.
Collapse
Affiliation(s)
- Hannah M Brown
- School of Health and Life Science, Teesside University, Middlesbrough, UK
- National Horizons Centre, Teesside University, Darlington, UK
| | - M Angeles Juanes
- School of Health and Life Science, Teesside University, Middlesbrough, UK.
- National Horizons Centre, Teesside University, Darlington, UK.
- Centro de Investigación Príncipe Felipe, Valencia, Spain.
| |
Collapse
|
4
|
Pozzi S, Scomparin A, Israeli Dangoor S, Rodriguez Ajamil D, Ofek P, Neufeld L, Krivitsky A, Vaskovich-Koubi D, Kleiner R, Dey P, Koshrovski-Michael S, Reisman N, Satchi-Fainaro R. Meet me halfway: Are in vitro 3D cancer models on the way to replace in vivo models for nanomedicine development? Adv Drug Deliv Rev 2021; 175:113760. [PMID: 33838208 DOI: 10.1016/j.addr.2021.04.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 03/24/2021] [Accepted: 04/01/2021] [Indexed: 12/12/2022]
Abstract
The complexity and diversity of the biochemical processes that occur during tumorigenesis and metastasis are frequently over-simplified in the traditional in vitro cell cultures. Two-dimensional cultures limit researchers' experimental observations and frequently give rise to misleading and contradictory results. Therefore, in order to overcome the limitations of in vitro studies and bridge the translational gap to in vivo applications, 3D models of cancer were developed in the last decades. The three dimensions of the tumor, including its cellular and extracellular microenvironment, are recreated by combining co-cultures of cancer and stromal cells in 3D hydrogel-based growth factors-inclusive scaffolds. More complex 3D cultures, containing functional blood vasculature, can integrate in the system external stimuli (e.g. oxygen and nutrient deprivation, cytokines, growth factors) along with drugs, or other therapeutic compounds. In this scenario, cell signaling pathways, metastatic cascade steps, cell differentiation and self-renewal, tumor-microenvironment interactions, and precision and personalized medicine, are among the wide range of biological applications that can be studied. Here, we discuss a broad variety of strategies exploited by scientists to create in vitro 3D cancer models that resemble as much as possible the biology and patho-physiology of in vivo tumors and predict faithfully the treatment outcome.
Collapse
Affiliation(s)
- Sabina Pozzi
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Anna Scomparin
- Department of Drug Science and Technology, University of Turin, Via P. Giuria 9, 10125 Turin, Italy
| | - Sahar Israeli Dangoor
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Daniel Rodriguez Ajamil
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Paula Ofek
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Lena Neufeld
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Adva Krivitsky
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Daniella Vaskovich-Koubi
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ron Kleiner
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Pradip Dey
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Shani Koshrovski-Michael
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Noa Reisman
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ronit Satchi-Fainaro
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel.
| |
Collapse
|
5
|
SpheroidPicker for automated 3D cell culture manipulation using deep learning. Sci Rep 2021; 11:14813. [PMID: 34285291 PMCID: PMC8292460 DOI: 10.1038/s41598-021-94217-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 06/24/2021] [Indexed: 12/26/2022] Open
Abstract
Recent statistics report that more than 3.7 million new cases of cancer occur in Europe yearly, and the disease accounts for approximately 20% of all deaths. High-throughput screening of cancer cell cultures has dominated the search for novel, effective anticancer therapies in the past decades. Recently, functional assays with patient-derived ex vivo 3D cell culture have gained importance for drug discovery and precision medicine. We recently evaluated the major advancements and needs for the 3D cell culture screening, and concluded that strictly standardized and robust sample preparation is the most desired development. Here we propose an artificial intelligence-guided low-cost 3D cell culture delivery system. It consists of a light microscope, a micromanipulator, a syringe pump, and a controller computer. The system performs morphology-based feature analysis on spheroids and can select uniform sized or shaped spheroids to transfer them between various sample holders. It can select the samples from standard sample holders, including Petri dishes and microwell plates, and then transfer them to a variety of holders up to 384 well plates. The device performs reliable semi- and fully automated spheroid transfer. This results in highly controlled experimental conditions and eliminates non-trivial side effects of sample variability that is a key aspect towards next-generation precision medicine.
Collapse
|
6
|
Jauković A, Abadjieva D, Trivanović D, Stoyanova E, Kostadinova M, Pashova S, Kestendjieva S, Kukolj T, Jeseta M, Kistanova E, Mourdjeva M. Specificity of 3D MSC Spheroids Microenvironment: Impact on MSC Behavior and Properties. Stem Cell Rev Rep 2021; 16:853-875. [PMID: 32681232 DOI: 10.1007/s12015-020-10006-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Mesenchymal stem cells (MSC) have been considered the promising candidates for the regenerative and personalized medicine due to their self-renewal potential, multilineage differentiation and immunomodulatory capacity. Although these properties have encouraged profound MSC studies in recent years, the majority of research has been based on standard 2D culture utilization. The opportunity to resemble in vivo characteristics of cells native niche has been provided by implementation of 3D culturing models such as MSC spheroid formation assesed through cells self-assembling. In this review, we address the current literature on physical and biochemical features of 3D MSC spheroid microenvironment and their impact on MSC properties and behaviors. Starting with the reduction in the cells' dimensions and volume due to the changes in adhesion molecules expression and cytoskeletal proteins rearrangement resembling native conditions, through the microenvironment shifts in oxygen, nutrients and metabolites gradients and demands, we focus on distinctive and beneficial features of MSC in spheroids compared to cells cultured in 2D conditions. By summarizing the data for 3D MSC spheroids regarding cell survival, pluripotency, differentiation, immunomodulatory activities and potential to affect tumor cells growth we highlighted advantages and perspectives of MSC spheroids use in regenerative medicine. Further detailed analyses are needed to deepen our understanding of mechanisms responsible for modified MSC behavior in spheroids and to set future directions for MSC clinical application.
Collapse
Affiliation(s)
- Aleksandra Jauković
- Laboratory for Experimental Hematology and Stem Cells, Institute for Medical Research, University of Belgrade, Dr. Subotića 4, PO BOX 102, Belgrade, 11129, Serbia
| | - Desislava Abadjieva
- Institute of Biology and Immunology of Reproduction, Bulgarian Academy of Sciences, 73 Tzarigradsko shoes, 1113, Sofia, Bulgaria
| | - Drenka Trivanović
- Laboratory for Experimental Hematology and Stem Cells, Institute for Medical Research, University of Belgrade, Dr. Subotića 4, PO BOX 102, Belgrade, 11129, Serbia.,IZKF Group Tissue Regeneration in Musculoskeletal Diseases, University Clinics, Röntgenring 11, D-97070, Wuerzburg, Germany.,Bernhard-Heine-Center for Locomotion Research, University Wuerzburg, Wuerzburg, Germany
| | - Elena Stoyanova
- Institute of Biology and Immunology of Reproduction, Bulgarian Academy of Sciences, 73 Tzarigradsko shoes, 1113, Sofia, Bulgaria
| | - Milena Kostadinova
- Institute of Biology and Immunology of Reproduction, Bulgarian Academy of Sciences, 73 Tzarigradsko shoes, 1113, Sofia, Bulgaria
| | - Shina Pashova
- Institute of Biology and Immunology of Reproduction, Bulgarian Academy of Sciences, 73 Tzarigradsko shoes, 1113, Sofia, Bulgaria
| | - Snejana Kestendjieva
- Institute of Biology and Immunology of Reproduction, Bulgarian Academy of Sciences, 73 Tzarigradsko shoes, 1113, Sofia, Bulgaria
| | - Tamara Kukolj
- Laboratory for Experimental Hematology and Stem Cells, Institute for Medical Research, University of Belgrade, Dr. Subotića 4, PO BOX 102, Belgrade, 11129, Serbia
| | - Michal Jeseta
- Department of Obstetrics and Gynecology, University Hospital and Masaryk University, Obilní trh 11, 602 00, Brno, Czech Republic.,Department of Veterinary Sciences, Czech University of Life Sciences in Prague, Kamýcká 129, 165 00, Suchdol, Praha 6, Czech Republic
| | - Elena Kistanova
- Institute of Biology and Immunology of Reproduction, Bulgarian Academy of Sciences, 73 Tzarigradsko shoes, 1113, Sofia, Bulgaria
| | - Milena Mourdjeva
- Institute of Biology and Immunology of Reproduction, Bulgarian Academy of Sciences, 73 Tzarigradsko shoes, 1113, Sofia, Bulgaria.
| |
Collapse
|
7
|
Mok S, Al Habyan S, Ledoux C, Lee W, MacDonald KN, McCaffrey L, Moraes C. Mapping cellular-scale internal mechanics in 3D tissues with thermally responsive hydrogel probes. Nat Commun 2020; 11:4757. [PMID: 32958771 PMCID: PMC7505969 DOI: 10.1038/s41467-020-18469-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 08/25/2020] [Indexed: 02/07/2023] Open
Abstract
Local tissue mechanics play a critical role in cell function, but measuring these properties at cellular length scales in living 3D tissues can present considerable challenges. Here we present thermoresponsive, smart material microgels that can be dispersed or injected into tissues and optically assayed to measure residual tissue elasticity after creep over several weeks. We first develop and characterize the sensors, and demonstrate that internal mechanical profiles of live multicellular spheroids can be mapped at high resolutions to reveal broad ranges of rigidity within the tissues, which vary with subtle differences in spheroid aggregation method. We then show that small sites of unexpectedly high rigidity develop in invasive breast cancer spheroids, and in an in vivo mouse model of breast cancer progression. These focal sites of increased intratumoral rigidity suggest new possibilities for how early mechanical cues that drive cancer cells towards invasion might arise within the evolving tumor microenvironment.
Collapse
Affiliation(s)
- Stephanie Mok
- Department of Chemical Engineering, McGill University, 3610 University Street, Montreal, QC, H3A 0C5, Canada
| | - Sara Al Habyan
- Rosalind and Morris Goodman Cancer Research Centre, McGill University, 160 Pine Ave W, Montreal, QC, H3A 1A3, Canada
| | - Charles Ledoux
- Department of Chemical Engineering, McGill University, 3610 University Street, Montreal, QC, H3A 0C5, Canada
| | - Wontae Lee
- Department of Chemical Engineering, McGill University, 3610 University Street, Montreal, QC, H3A 0C5, Canada
| | - Katherine N MacDonald
- Department of Chemical Engineering, McGill University, 3610 University Street, Montreal, QC, H3A 0C5, Canada
| | - Luke McCaffrey
- Rosalind and Morris Goodman Cancer Research Centre, McGill University, 160 Pine Ave W, Montreal, QC, H3A 1A3, Canada
| | - Christopher Moraes
- Department of Chemical Engineering, McGill University, 3610 University Street, Montreal, QC, H3A 0C5, Canada.
- Rosalind and Morris Goodman Cancer Research Centre, McGill University, 160 Pine Ave W, Montreal, QC, H3A 1A3, Canada.
- Department of Biomedical Engineering, McGill University, 3775 University Street, Montreal, QC, H3A 2B4, Canada.
| |
Collapse
|
8
|
Ndyabawe K, Haidekker M, Asthana A, Kisaalita WS. Spheroid Trapping and Calcium Spike Estimation Techniques toward Automation of 3D Culture. SLAS Technol 2020; 26:265-273. [PMID: 32672140 DOI: 10.1177/2472630320938319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We present a spheroid trapping device, compatible with traditional tissue culture plates, to confine microtissues in a small area and allow suspension cultures to be treated like adherent cultures with minimal loss of spheroids due to aspiration. We also illustrate an automated morphology-independent procedure for cell recognition, segmentation, and a calcium spike detection technique for high-throughput analysis in 3D cultured tissue. Our cell recognition technique uses a maximum intensity projection of spatial-temporal data to create a binary mask, which delineates individual cell boundaries and extracts mean fluorescent data for each cell through a series of intensity thresholding and cluster labeling operations. The temporal data are subject to sorting for imaging artifacts, baseline correction, smoothing, and spike detection algorithms. We validated this procedure through analysis of calcium data from 2D and 3D SHSY-5Y cell cultures. Using this approach, we rapidly created regions of interest (ROIs) and extracted fluorescent intensity data from hundreds of cells in the field of view with superior data fidelity over hand-drawn ROIs even in dense (3D tissue) cell populations. We sorted data from cells with imaging artifacts (such as photo bleaching and dye saturation), classified nonfiring and firing cells, estimated the number of spikes in each cell, and documented the results, facilitating large-scale calcium imaging analysis in both 2D and 3D cultures. Since our recognition and segmentation technique is independent of morphology, our protocol provides a versatile platform for the analysis of large confocal calcium imaging data from neuronal cells, glial cells, and other cell types.
Collapse
Affiliation(s)
- Kenneth Ndyabawe
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA, USA
| | - Mark Haidekker
- School of Electrical and Computer Engineering, College of Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA, USA
| | - Amish Asthana
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA, USA
| | - William S Kisaalita
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA, USA
| |
Collapse
|
9
|
Chew D, Green V, Riley A, England RJ, Greenman J. The Changing Face of in vitro Culture Models for Thyroid Cancer Research: A Systematic Literature Review. Front Surg 2020; 7:43. [PMID: 32766274 PMCID: PMC7378741 DOI: 10.3389/fsurg.2020.00043] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 06/08/2020] [Indexed: 12/12/2022] Open
Abstract
Background: Thyroid cancer is the most common endocrine malignancy worldwide. Primary treatment with surgery and radioactive iodine is usually successful, however, there remains a small proportion of thyroid cancers that are resistant to these treatments, and often represent aggressive forms of the disease. Since the 1950s, in vitro thyroid culture systems have been used in thyroid cancer research. In vitro culture models have evolved from 2-dimensional thyrocyte monolayers into physiologically functional 3-dimensional organoids. Recently, research groups have utilized in vitro thyroid cancer models to identify numerous genetic and epigenetic factors that are involved with tumorigenesis as well as test the efficacy of cytotoxic drugs on thyroid cancer cells and identify cancer stem cells within thyroid tumors. Objective of Review: The objective of this literature review is to summarize how thyroid in vitro culture models have evolved and highlight how in vitro models have been fundamental to thyroid cancer research. Type of Review: Systematic literature review. Search Strategy: The National Institute for Health and Care Excellence (NICE) Healthcare and Databases Advanced Search (HDAS) tool was used to search EMBASE, Medline and PubMed databases. The following terms were included in the search: “in vitro” AND “thyroid cancer”. The search period was confined from January 2008 until June 2019. A manual search of the references of review articles and other key articles was also performed using Google Scholar. Evaluation Method: All experimental studies and review articles that explicitly mentioned the use of in vitro models for thyroid cancer research in the title and/or abstract were considered. Full-text versions of all selected articles were evaluated. Experimental studies were reviewed and grouped according to topic: genetics/epigenetics, drug testing/cancer treatment, and side populations (SP)/tumor microenvironment (TME). Results: Three thousand three hundred and seventy three articles were identified through database and manual searches. One thousand two hundred and sixteen articles remained after duplicates were removed. Five hundred and eighty nine articles were excluded based on title and/or abstract. Of the remaining 627 full-text articles: 24 were review articles, 332 related to genetic/epigenetics, 240 related to drug testing/treatments, and 31 related to SP/TME. Conclusion:In vitro cell culture models have been fundamental in thyroid cancer research. There have been many advances in culture techniques- developing complex cellular architecture that more closely resemble tumors in vivo. Genetic and epigenetic factors that have been identified using in vitro culture models can be used as targets for novel drug therapies. In the future, in vitro systems will facilitate personalized medicine, offering bespoke treatments to patients.
Collapse
Affiliation(s)
- Dylan Chew
- Department of ENT, Hull University Teaching Hospitals NHS Trust, Castle Hill Hospital, London, United Kingdom
| | - Victoria Green
- Department of Biomedical Sciences, University of Hull, Hull, United Kingdom
| | - Andrew Riley
- Department of Biomedical Sciences, University of Hull, Hull, United Kingdom
| | - Richard James England
- Department of ENT, Hull University Teaching Hospitals NHS Trust, Castle Hill Hospital, London, United Kingdom.,Department of Biomedical Sciences, University of Hull, Hull, United Kingdom
| | - John Greenman
- Department of Biomedical Sciences, University of Hull, Hull, United Kingdom
| |
Collapse
|
10
|
Monteiro CF, Santos SC, Custódio CA, Mano JF. Human Platelet Lysates-Based Hydrogels: A Novel Personalized 3D Platform for Spheroid Invasion Assessment. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:1902398. [PMID: 32274296 PMCID: PMC7141025 DOI: 10.1002/advs.201902398] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 12/19/2019] [Indexed: 05/04/2023]
Abstract
Fundamental physiologic and pathologic phenomena such as wound healing and cancer metastasis are typically associated with the migration of cells through adjacent extracellular matrix. In recent years, advances in biomimetic materials have supported the progress in 3D cell culture and provided biomedical tools for the development of models to study spheroid invasiveness. Despite this, the exceptional biochemical and biomechanical properties of human-derived materials are poorly explored. Human methacryloyl platelet lysates (PLMA)-based hydrogels are herein proposed as reliable 3D platforms to sustain in vivo-like cell invasion mechanisms. A systematic analysis of spheroid viability, size, and invasiveness is performed in three biomimetic materials: PLMA hydrogels at three different concentrations, poly(ethylene glycol) diacrylate, and Matrigel. Results demonstrate that PLMA hydrogels perfectly support the recapitulation of the tumor invasion behavior of cancer cell lines (MG-63, SaOS-2, and A549) and human bone-marrow mesenchymal stem cell spheroids. The distinct invasiveness ability of each cell type is reflected in the PLMA hydrogels and, furthermore, different mechanical properties produce an altered invasive behavior. The herein presented human PLMA-based hydrogels could represent an opportunity to develop accurate cell invasiveness models and open up new possibilities for humanized and personalized high-throughput screening and validation of anticancer drugs.
Collapse
Affiliation(s)
- Cátia F. Monteiro
- Department of ChemistryCICECOUniversity of AveiroCampus Universitário de Santiago3810‐193AveiroPortugal
| | - Sara C. Santos
- Department of ChemistryCICECOUniversity of AveiroCampus Universitário de Santiago3810‐193AveiroPortugal
| | - Catarina A. Custódio
- Department of ChemistryCICECOUniversity of AveiroCampus Universitário de Santiago3810‐193AveiroPortugal
| | - João F. Mano
- Department of ChemistryCICECOUniversity of AveiroCampus Universitário de Santiago3810‐193AveiroPortugal
| |
Collapse
|
11
|
Cardoso AMS, Sousa M, Morais CM, Oancea-Castillo LR, Régnier-Vigouroux A, Rebelo O, Tão H, Barbosa M, Pedroso MCDL, Jurado AS. MiR-144 overexpression as a promising therapeutic strategy to overcome glioblastoma cell invasiveness and resistance to chemotherapy. Hum Mol Genet 2020; 28:2738-2751. [PMID: 31087038 DOI: 10.1093/hmg/ddz099] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 04/30/2019] [Accepted: 05/01/2019] [Indexed: 12/15/2022] Open
Abstract
Glioblastoma (GB) is the most aggressive and common form of primary brain tumor, characterized by fast proliferation, high invasion, and resistance to current standard treatment. The average survival rate post-diagnosis is only of 14.6 months, despite the aggressive standard post-surgery treatment approaches of radiotherapy concomitant with chemotherapy with temozolomide. Altered cell metabolism has been identified as an emerging cancer hallmark, including in GB, thus offering a new target for cancer therapies. On the other hand, abnormal expression levels of miRNAs, key regulators of multiple molecular pathways, have been correlated with pathological manifestations of cancer, such as chemoresistance, proliferation, and resistance to apoptosis. In this work, we hypothesized that gene therapy based on modulation of a miRNA with aberrant expression in GB and predicted to target crucial metabolic enzymes might impair tumor cell metabolism. We found that the increase of miR-144 levels, shown to be downregulated in U87 and DBTRG human GB cell lines, as well as in GB tumor samples, promoted the downregulation of mRNA of enzymes involved in bioenergetic pathways, with consequent alterations in cell metabolism, impairment of migratory capacity, and sensitization of DBTRG cells to a chemotherapeutic drug, the dichloroacetate (DCA). Taken together, our findings provide evidence that the miR-144 plus DCA combined therapy holds promise to overcome GB-acquired chemoresistance, therefore deserving to be explored toward its potential application as a complementary therapeutic approach to the current treatment options for this type of brain tumor.
Collapse
Affiliation(s)
- Ana M S Cardoso
- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal.,Institute for Interdisciplinary Research of the University of Coimbra, 3030-789 Coimbra, Portugal
| | - Madalena Sousa
- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal.,Department of Life Sciences, Faculty of Science and Technology, University of Coimbra, 3000-456 Coimbra, Portugal
| | - Catarina M Morais
- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal.,Department of Life Sciences, Faculty of Science and Technology, University of Coimbra, 3000-456 Coimbra, Portugal
| | - Liliana R Oancea-Castillo
- Institute for Developmental Biology and Neurobiology, Johannes Gutenberg University of Mainz, 55128 Mainz, Germany
| | - Anne Régnier-Vigouroux
- Institute for Developmental Biology and Neurobiology, Johannes Gutenberg University of Mainz, 55128 Mainz, Germany
| | - Olinda Rebelo
- Neuropathology Laboratory, Neurology Service, University Hospital of Coimbra, 3004-561 Coimbra, Portugal
| | - Hermínio Tão
- Neurosurgery Service, University Hospital of Coimbra, 3004-561 Coimbra, Portugal
| | - Marcos Barbosa
- Neurosurgery Service, University Hospital of Coimbra, 3004-561 Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
| | | | - Amália S Jurado
- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal.,Department of Life Sciences, Faculty of Science and Technology, University of Coimbra, 3000-456 Coimbra, Portugal
| |
Collapse
|
12
|
Murgoci AN, Duhamel M, Raffo-Romero A, Mallah K, Aboulouard S, Lefebvre C, Kobeissy F, Fournier I, Zilkova M, Maderova D, Cizek M, Cizkova D, Salzet M. Location of neonatal microglia drives small extracellular vesicles content and biological functions in vitro. J Extracell Vesicles 2020; 9:1727637. [PMID: 32158520 PMCID: PMC7049881 DOI: 10.1080/20013078.2020.1727637] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 01/31/2020] [Accepted: 02/03/2020] [Indexed: 12/19/2022] Open
Abstract
Combining proteomics and systems biology approaches, we demonstrate that neonatal microglial cells derived from two different CNS locations, cortex and spinal cord, and cultured in vitro displayed different phenotypes upon different physiological or pathological conditions. These cells also exhibited greater variability in terms of cellular and small extracellular vesicles (sEVs) protein content and levels. Bioinformatic data analysis showed that cortical microglia exerted anti-inflammatory and neurogenesis/tumorigenesis properties, while the spinal cord microglia were more inflammatory. Interestingly, while both sEVs microglia sources enhanced growth of DRGs processes, only the spinal cord-derived sEVs microglia under LPS stimulation significantly attenuated glioma proliferation. These results were confirmed using the neurite outgrowth assay on DRGs cells and glioma proliferation analysis in 3D spheroid cultures. Results from these in vitro assays suggest that the microglia localized at different CNS regions can ensure different biological functions. Together, this study indicates that neonatal microglia locations regulate their physiological and pathological functional fates and could affect the high prevalence of brain vs spinal cord gliomas in adults.
Collapse
Affiliation(s)
- Adriana-Natalia Murgoci
- Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, Université Lille, Villeneuve d’Ascq, France
- Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovakia
- Department of Anatomy, Histology and Physiology, University of Veterinary Medicine and Pharmacy in Košice, Košice, Slovakia
| | - Marie Duhamel
- Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, Université Lille, Villeneuve d’Ascq, France
| | - Antonella Raffo-Romero
- Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, Université Lille, Villeneuve d’Ascq, France
| | - Khalil Mallah
- Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, Université Lille, Villeneuve d’Ascq, France
| | - Soulaimane Aboulouard
- Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, Université Lille, Villeneuve d’Ascq, France
| | - Christophe Lefebvre
- Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, Université Lille, Villeneuve d’Ascq, France
| | - Firas Kobeissy
- Department of Psychiatry, McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Isabelle Fournier
- Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, Université Lille, Villeneuve d’Ascq, France
| | - Monika Zilkova
- Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Denisa Maderova
- Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Milan Cizek
- Department of Epizootiology and Parasitology, University of Veterinary Medicine and Pharmacy in Košice, KošiceSlovakia
| | - Dasa Cizkova
- Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, Université Lille, Villeneuve d’Ascq, France
- Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovakia
- Department of Anatomy, Histology and Physiology, University of Veterinary Medicine and Pharmacy in Košice, Košice, Slovakia
| | - Michel Salzet
- Inserm, U-1192 - Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, Université Lille, Villeneuve d’Ascq, France
| |
Collapse
|
13
|
Lim GJ, Kang SJ, Lee JY. Novel invasion indices quantify the feed-forward facilitation of tumor invasion by macrophages. Sci Rep 2020; 10:718. [PMID: 31959808 PMCID: PMC6971071 DOI: 10.1038/s41598-020-57517-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 01/02/2020] [Indexed: 01/08/2023] Open
Abstract
Quantitative and reliable measurement of cellular invasion is important to understand a range of biological processes such as cancer metastasis and angiogenesis. Spheroid invasion assays are an attractive in vitro platform because they effectively mimic the tumor cell invasion of solid tissues. Here, we developed an image analysis–based method to quantify the invasiveness of HT1080 human fibrosarcoma tumor cell spheroids. We segmented a cell-covered area into three subareas using objectively set threshold pixel intensities and calculated invasion indices using these subareas. Comparison with conventional parameters for spheroid invasion assays, such as area, length, and detached cells, showed that our indices present the invasion event at an early time and without being convoluted by proliferation. As an application, we then examined paracrine interactions between LLC1 mouse lung carcinoma cells and Raw264.7 mouse macrophage cells with our developed analysis method. We found that the invasion of tumor spheroids was increased by a macrophage-conditioned medium, concomitantly with a decrease in tumor cell proliferation. Importantly, invasion was further enhanced by a conditioned medium from activated macrophages by co-culture with tumor cells. Thus, our indices reveal that tumor cell invasion is facilitated in a feed-forward manner by communication between tumor cells and macrophages in the tumor microenvironment.
Collapse
Affiliation(s)
- Gippeum J Lim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Suk-Jo Kang
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea.
| | - Ji Youn Lee
- Center for Bioanalysis, Division of Chemical and Medical Metrology, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon, 34113, Republic of Korea.
| |
Collapse
|
14
|
3D multicellular models to study the regulation and roles of acid-base transporters in breast cancer. Biochem Soc Trans 2019; 47:1689-1700. [PMID: 31803922 DOI: 10.1042/bst20190131] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 11/01/2019] [Accepted: 11/12/2019] [Indexed: 12/24/2022]
Abstract
As a result of elevated metabolic rates and net acid extrusion in the rapidly proliferating cancer cells, solid tumours are characterized by a highly acidic microenvironment, while cancer cell intracellular pH is normal or even alkaline. Two-dimensional (2D) cell monocultures, which have been used extensively in breast cancer research for decades, cannot precisely recapitulate the rich environment and complex processes occurring in tumours in vivo. The use of such models can consequently be misleading or non-predictive for clinical applications. Models mimicking the tumour microenvironment are particularly pivotal for studying tumour pH homeostasis, which is profoundly affected by the diffusion-limited conditions in the tumour. To advance the understanding of the mechanisms and consequences of dysregulated acid-base homeostasis in breast cancer, clinically relevant models that incorporate the unique microenvironment of these tumours are required. The development of three-dimensional (3D) cell cultures has provided new tools for basic research and pre-clinical approaches, allowing the culture of breast cancer cells under conditions that closely resemble tumour growth in a living organism. Here we provide an overview of the main 3D techniques relevant for breast cancer cell culture. We discuss the advantages and limitations of the classical 3D models as well as recent advances in 3D culture techniques, focusing on how these culture methods have been used to study acid-base transport in breast cancer. Finally, we outline future directions of 3D culture technology and their relevance for studies of acid-base transport.
Collapse
|
15
|
Hu Q, Myers M, Fang W, Yao M, Brummer G, Hawj J, Smart C, Berkland C, Cheng N. Role of ALDH1A1 and HTRA2 expression in CCL2/CCR2-mediated breast cancer cell growth and invasion. Biol Open 2019; 8:bio.040873. [PMID: 31208996 PMCID: PMC6679398 DOI: 10.1242/bio.040873] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Chemokines mediate immune cell trafficking during tissue development, wound healing and infection. The chemokine CCL2 is best known to regulate macrophage recruitment during wound healing, infection and inflammatory diseases. While the importance of CCL2/CCR2 signaling in macrophages during cancer progression is well documented, we recently showed that CCL2-mediated breast cancer progression depends on CCR2 expression in carcinoma cells. Using 3D Matrigel: Collagen cultures of SUM225 and DCIS.com breast cancer cells, this study characterized the mechanisms of CCL2/CCR2 signaling in cell growth and invasion. SUM225 cells, which expressed lower levels of CCR2 than DCIS.com cells, formed symmetrical spheroids in Matrigel: Collagen, and were not responsive to CCL2 treatment. DCIS.com cells formed asymmetric cell clusters in Matrigel: Collagen. CCL2 treatment increased growth, decreased expression of E-cadherin and increased TWIST1 expression. CCR2 overexpression in SUM225 cells increased responsiveness to CCL2 treatment, enhancing growth and invasion. These phenotypes corresponded to increased expression of Aldehyde Dehydrogenase 1A1 (ALDH1A1) and decreased expression of the mitochondrial serine protease HTRA2. CCR2 deficiency in DCIS.com cells inhibited CCL2-mediated growth and invasion, corresponding to decreased ALDH1A1 expression and increased HTRA2 expression. ALDH1A1 and HTRA2 expression were modulated in CCR2-deficient and CCR2-overexpressing cell lines. We found that ALDH1A1 and HTRA2 regulates CCR2-mediated breast cancer cell growth and cellular invasion in a CCL2/CCR2 context-dependent manner. These data provide novel insight on the mechanisms of chemokine signaling in breast cancer cell growth and invasion, with important implications on targeted therapeutics for anti-cancer treatment. This article has an associated First Person interview with the first author of the paper. Summary: Chemokines are known to regulate immune cell recruitment during inflammation. This report characterizes novel molecular mechanisms through which CCL2/CCR2 chemokine signaling in breast cancer cells regulates growth and invasion.
Collapse
Affiliation(s)
- Qingting Hu
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Megan Myers
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Wei Fang
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Min Yao
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Gage Brummer
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Justin Hawj
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Curtis Smart
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Cory Berkland
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66047, USA
| | - Nikki Cheng
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA .,Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| |
Collapse
|
16
|
Ebegboni VJ, Balahmar RM, Dickenson JM, Sivasubramaniam SD. The effects of flavonoids on human first trimester trophoblast spheroidal stem cell self-renewal, invasion and JNK/p38 MAPK activation: Understanding the cytoprotective effects of these phytonutrients against oxidative stress. Biochem Pharmacol 2019; 164:289-298. [PMID: 31022396 DOI: 10.1016/j.bcp.2019.04.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 04/19/2019] [Indexed: 12/19/2022]
Abstract
Adequate invasion and complete remodelling of the maternal spiral arteries by the invading extravillous trophoblasts are the major determinants of a successful pregnancy. Increase in oxidative stress during pregnancy has been linked to the reduction in trophoblast invasion and incomplete conversion of the maternal spiral arteries, resulting in pregnancy complications such as pre-eclampsia, intrauterine growth restriction, and spontaneous miscarriages resulting in foetal/maternal mortality. The use of antioxidant therapy (vitamin C and E) and other preventative treatments (such as low dose aspirin) have been ineffective in preventing pre-eclampsia. Also, as the majority of antihypertensive drugs pose side effects, choosing an appropriate treatment would depend upon the efficacy and safety of mother/foetus. Since pre-eclampsia is mainly linked to placental oxidative stress, new diet-based antioxidants can be of use to prevent this condition. The antioxidant properties of flavonoids (naturally occurring phenolic compounds which are ubiquitously distributed in fruits and vegetables) have been well documented in non-trophoblast cells. Therefore, this study aimed to investigate the effects of flavonoids (quercetin, hesperidin) and their metabolites (Quercetin 3-O-β-glucuronide and hesperetin), either alone or in combination, on first trimester trophoblast cell line HTR-8/SVneo during oxidative stress. The data obtained from this study indicate that selected flavonoids, their respective metabolites significantly reduced the levels of reduced glutathione (p < 0.0001) during HR-induced oxidative stress. These flavonoids also inhibited the activation of pro-apoptotic kinases (p38 MAPK and c-Jun N-terminal kinase) during HR-induced phosphorylation. In addition, they enhanced spheroid stem-like cell generation from HTR8/SVneo cells, aiding their invasion. Our data suggest that dietary intake of food rich in quercetin or hesperidin during early pregnancy can significantly improve trophoblast (placenta) health and function against oxidative stress.
Collapse
Affiliation(s)
- Vernon J Ebegboni
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK
| | - Reham M Balahmar
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK
| | - John M Dickenson
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK
| | - Shiva D Sivasubramaniam
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK; School of Human Sciences, University of Derby, Kidleston Road, Derby DE22, 1GB, UK.
| |
Collapse
|
17
|
Dispersible hydrogel force sensors reveal patterns of solid mechanical stress in multicellular spheroid cultures. Nat Commun 2019; 10:144. [PMID: 30635553 PMCID: PMC6329783 DOI: 10.1038/s41467-018-07967-4] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Accepted: 12/07/2018] [Indexed: 12/24/2022] Open
Abstract
Understanding how forces orchestrate tissue formation requires technologies to map internal tissue stress at cellular length scales. Here, we develop ultrasoft mechanosensors that visibly deform under less than 10 Pascals of cell-generated stress. By incorporating these mechanosensors into multicellular spheroids, we capture the patterns of internal stress that arise during spheroid formation. We experimentally demonstrate the spontaneous generation of a tensional 'skin', only a few cell layers thick, at the spheroid surface, which correlates with activation of mechanobiological signalling pathways, and balances a compressive stress profile within the tissue. These stresses develop through cell-driven mechanical compaction at the tissue periphery, and suggest that the tissue formation process plays a critically important role in specifying mechanobiological function. The broad applicability of this technique should ultimately provide a quantitative basis to design tissues that leverage the mechanical activity of constituent cells to evolve towards a desired form and function.
Collapse
|
18
|
da Conceicao Ribeiro R, Pal D, Ferreira AM, Gentile P, Benning M, Dalgarno K. Reactive jet impingement bioprinting of high cell density gels for bone microtissue fabrication. Biofabrication 2018; 11:015014. [DOI: 10.1088/1758-5090/aaf625] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
|
19
|
García I, Henriksen-Lacey M, Calvo J, de Aberasturi DJ, Paz MM, Liz-Marzán LM. Size-Dependent Transport and Cytotoxicity of Mitomycin-Gold Nanoparticle Conjugates in 2D and 3D Mammalian Cell Models. Bioconjug Chem 2018; 30:242-252. [DOI: 10.1021/acs.bioconjchem.8b00898] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Isabel García
- Biomedical Research Networking Center in Bioengineering Biomaterials and Nanomedicine (CIBER-BBN), 20014 Donostia-San Sebastián, Spain
- CIC biomaGUNE, Paseo de Miramón 182, 20014 Donostia-San Sebastián, Spain
| | - Malou Henriksen-Lacey
- Biomedical Research Networking Center in Bioengineering Biomaterials and Nanomedicine (CIBER-BBN), 20014 Donostia-San Sebastián, Spain
- CIC biomaGUNE, Paseo de Miramón 182, 20014 Donostia-San Sebastián, Spain
| | - Javier Calvo
- CIC biomaGUNE, Paseo de Miramón 182, 20014 Donostia-San Sebastián, Spain
| | - Dorleta Jimenez de Aberasturi
- Biomedical Research Networking Center in Bioengineering Biomaterials and Nanomedicine (CIBER-BBN), 20014 Donostia-San Sebastián, Spain
- CIC biomaGUNE, Paseo de Miramón 182, 20014 Donostia-San Sebastián, Spain
| | - Manuel M. Paz
- Departamento de Química Orgánica, Facultade de Química, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Luis M. Liz-Marzán
- Biomedical Research Networking Center in Bioengineering Biomaterials and Nanomedicine (CIBER-BBN), 20014 Donostia-San Sebastián, Spain
- CIC biomaGUNE, Paseo de Miramón 182, 20014 Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
| |
Collapse
|
20
|
Oraiopoulou ME, Tzamali E, Tzedakis G, Liapis E, Zacharakis G, Vakis A, Papamatheakis J, Sakkalis V. Integrating in vitro experiments with in silico approaches for Glioblastoma invasion: the role of cell-to-cell adhesion heterogeneity. Sci Rep 2018; 8:16200. [PMID: 30385804 PMCID: PMC6212459 DOI: 10.1038/s41598-018-34521-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 10/01/2018] [Indexed: 01/08/2023] Open
Abstract
Glioblastoma cells adopt migration strategies to invade into the brain parenchyma ranging from individual to collective mechanisms, whose role and dynamics are not yet fully understood. In this work, we explore Glioblastoma heterogeneity and recapitulate its invasive patterns both in vitro, by utilizing primary cells along with the U87MG cell line, and in silico, by adopting discrete, individual cell-based mathematics. Glioblastoma cells are cultured three-dimensionally in an ECM-like substrate. The primary Glioblastoma spheroids adopt a novel cohesive pattern, mimicking perivascular invasion in the brain, while the U87MG adopt a typical, starburst invasive pattern under the same experimental setup. Mathematically, we focus on the role of the intrinsic heterogeneity with respect to cell-to-cell adhesion. Our proposed mathematical approach mimics the invasive morphologies observed in vitro and predicts the dynamics of tumour expansion. The role of the proliferation and migration is also explored showing that their effect on tumour morphology is different per cell type. The proposed model suggests that allowing cell-to-cell adhesive heterogeneity within the tumour population is sufficient for variable invasive morphologies to emerge which remain originally undetectable by conventional imaging, indicating that exploration in pathological samples is needed to improve our understanding and reveal potential patient-specific therapeutic targets.
Collapse
Affiliation(s)
- M-E Oraiopoulou
- Department of Medicine, University of Crete, Heraklion, Crete, Greece
- Computational Bio-Medicine Laboratory, Institute of Computer Science, Foundation for Research and Technology-Hellas, Heraklion, Crete, Greece
| | - E Tzamali
- Computational Bio-Medicine Laboratory, Institute of Computer Science, Foundation for Research and Technology-Hellas, Heraklion, Crete, Greece
| | - G Tzedakis
- Computational Bio-Medicine Laboratory, Institute of Computer Science, Foundation for Research and Technology-Hellas, Heraklion, Crete, Greece
| | - E Liapis
- Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas, Heraklion, Crete, Greece
- Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - G Zacharakis
- Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas, Heraklion, Crete, Greece
| | - A Vakis
- Department of Medicine, University of Crete, Heraklion, Crete, Greece
- Neurosurgery Clinic, University General Hospital of Heraklion, Crete, Greece
| | - J Papamatheakis
- Gene Expression Laboratory, Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Crete, Greece
- Department of Biology, University of Crete, Heraklion, Crete, Greece
| | - V Sakkalis
- Computational Bio-Medicine Laboratory, Institute of Computer Science, Foundation for Research and Technology-Hellas, Heraklion, Crete, Greece.
| |
Collapse
|
21
|
Kim H, Cho CH, Park JK. High-throughput culture and embedment of spheroid array using droplet contact-based spheroid transfer. BIOMICROFLUIDICS 2018; 12:044109. [PMID: 30867862 PMCID: PMC6404923 DOI: 10.1063/1.5039965] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Accepted: 07/01/2018] [Indexed: 05/17/2023]
Abstract
Spheroids are one of the most representative models of 3D cell culture, which can be easily formed using conventional hanging drop method. However, medium change and spheroid transferring process are the bottlenecks that reduce the throughput of the entire process in the hanging drop culture. In addition, the embedment of spheroid into hydrogel still depends on the individual pipetting process. To overcome these issues, we present poly(dimethylsiloxane) (PDMS)-based simple devices which can exploit droplet contact-based spheroid transfer using a drop array chip (DAC) having an array of well structures and peripheral rims. When the upper spheroid-containing drops were in contact with the lower liquid drops, the air-liquid interface disappeared at the merged surface and the spheroids settled down due to gravitational force. This method was applied to repetitive medium change and live/dead staining of spheroids cultured with the hanging drop method. To simultaneously embed the spheroids into the corresponding collagen hydrogel drops, a PDMS-based pillar array chip (PAC) was contacted in advance with the spheroid-containing DAC. The contacted PAC then contained the spheroids trapped in small drops of liquid reduced in volume to around 0.5 μl. Consequently, the spheroids were embedded into the collagen drops at once by contacting the spheroid-containing PAC with the collagen-loaded DAC. The embedded spheroids using the DAC-PAC contacting method showed a reliable invasion behavior compared to the embedded spheroids using conventional manual pipetting.
Collapse
Affiliation(s)
- Hwisoo Kim
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Chang Hyun Cho
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Je-Kyun Park
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| |
Collapse
|
22
|
Kenney RM, Lloyd CC, Whitman NA, Lockett MR. 3D cellular invasion platforms: how do paper-based cultures stack up? Chem Commun (Camb) 2018. [PMID: 28621775 DOI: 10.1039/c7cc02357j] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Cellular invasion is the gateway to metastasis, which is the leading cause of cancer-related deaths. Invasion is driven by a number of chemical and mechanical stresses that arise in the tumor microenvironment. In vitro assays are needed for the systematic study of cancer progress. To be truly predictive, these assays must generate tissue-like environments that can be experimentally controlled and manipulated. While two-dimensional (2D) monolayer cultures are easily assembled and evaluated, they lack the extracellular components needed to assess invasion. Three-dimensional (3D) cultures are better suited for invasion studies because they generate cellular phenotypes that are more representative of those found in vivo. This feature article provides an overview of four invasion platforms. We focus on paper-based cultures, an emerging 3D culture platform capable of generating tissue-like structures and quantifying cellular invasion. Paper-based cultures are as easily assembled and analyzed as monolayers, but provide an experimentally powerful platform capable of supporting: co-cultures and representative extracellular environments; experimentally controlled gradients; readouts capable of quantifying, discerning, and separating cells based on their invasiveness. With a series of examples we highlight the potential of paper-based cultures, and discuss how they stack up against other invasion platforms.
Collapse
Affiliation(s)
- Rachael M Kenney
- Department of Chemistry, University of North Carolina at Chapel Hill, Kenan and Caudill Laboratories, 125 South Road, Chapel Hill, NC 27599-3290, USA.
| | | | | | | |
Collapse
|
23
|
Murgoci AN, Cizkova D, Majerova P, Petrovova E, Medvecky L, Fournier I, Salzet M. Brain-Cortex Microglia-Derived Exosomes: Nanoparticles for Glioma Therapy. Chemphyschem 2018; 19:1205-1214. [PMID: 29327816 DOI: 10.1002/cphc.201701198] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/03/2018] [Indexed: 12/19/2022]
Abstract
The function and integrity of the nervous system require interactive exchanges among neurons and glial cells. Exosomes and other extracellular vesicles (EVs) are emerging as a key mediator of intercellular communication, capable of transferring nucleic acids, proteins and lipids influencing numerous functional and pathological aspects of both donor and recipient cells. The immune response mediated by microglia-derived exosomes is most prominently involved in the spread of neuroinflammation, neurodegenerative disorders, and brain cancer. Therefore, in the present study we describe a reproducible and highly efficient method for yielding purified primary microglia cells, followed by exosome isolation and their characterization. An in vitro biological assay demonstrates that microglia-derived exosomes tested on a 3D spheroid glioma culture were able to inhibit tumor invasion in time course. These results evidence that brain microglia-derived exosomes could be used as nanotherapeutic agents against glioma cells.
Collapse
Affiliation(s)
- Adriana-Natalia Murgoci
- Univ. Lille, Inserm, U-1192-Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, F-59000, Lille, France.,Institute of Neuroimmunology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 10, Bratislava, Slovakia.,Department of Anatomy, Histology and Physiology, University of Veterinary Medicine and Pharmacy in Košice, Komenského 73, 041 81, Košice, Slovakia
| | - Dasa Cizkova
- Univ. Lille, Inserm, U-1192-Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, F-59000, Lille, France.,Institute of Neuroimmunology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 10, Bratislava, Slovakia.,Department of Anatomy, Histology and Physiology, University of Veterinary Medicine and Pharmacy in Košice, Komenského 73, 041 81, Košice, Slovakia
| | - Petra Majerova
- Institute of Neuroimmunology, Slovak Academy of Sciences, Dúbravská cesta 9, 845 10, Bratislava, Slovakia
| | - Eva Petrovova
- Department of Anatomy, Histology and Physiology, University of Veterinary Medicine and Pharmacy in Košice, Komenského 73, 041 81, Košice, Slovakia
| | - Lubomir Medvecky
- Institute of Materials Research, Slovak Academy of Sciences, Watsonova 47, 040 01, Košice, Slovakia
| | - Isabelle Fournier
- Univ. Lille, Inserm, U-1192-Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, F-59000, Lille, France
| | - Michel Salzet
- Univ. Lille, Inserm, U-1192-Laboratoire Protéomique, Réponse Inflammatoire et Spectrométrie de Masse-PRISM, F-59000, Lille, France
| |
Collapse
|
24
|
Organotypic three-dimensional cancer cell cultures mirror drug responses in vivo: lessons learned from the inhibition of EGFR signaling. Oncotarget 2017; 8:107423-107440. [PMID: 29296175 PMCID: PMC5746077 DOI: 10.18632/oncotarget.22475] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 10/27/2017] [Indexed: 01/07/2023] Open
Abstract
Complex three-dimensional (3D) in vitro models that recapitulate human tumor biology are essential to understand the pathophysiology of the disease and to aid in the discovery of novel anti-cancer therapies. 3D organotypic cultures exhibit intercellular communication, nutrient and oxygen gradients, and cell polarity that is lacking in two-dimensional (2D) monolayer cultures. In the present study, we demonstrate that 2D and 3D cancer models exhibit different drug sensitivities towards both targeted inhibitors of EGFR signaling and broad acting cytotoxic agents. Changes in the kinase activities of ErbB family members and differential expression of apoptosis- and survival-associated genes before and after drug treatment may account for the differential drug sensitivities. Importantly, EGFR oncoprotein addiction was evident only in the 3D cultures mirroring the effect of EGFR inhibition in the clinic. Furthermore, targeted drug efficacy was strongly increased when incorporating cancer-associated fibroblasts into the 3D cultures. Taken together, we provide conclusive evidence that complex 3D cultures are more predictive of the clinical outcome than their 2D counterparts. In the future, 3D cultures will be instrumental for understanding the mode of action of drugs, identifying genotype-drug response relationships and developing patient-specific and personalized cancer treatments.
Collapse
|
25
|
Tevis KM, Colson YL, Grinstaff MW. Embedded Spheroids as Models of the Cancer Microenvironment. ADVANCED BIOSYSTEMS 2017; 1:1700083. [PMID: 30221187 PMCID: PMC6135264 DOI: 10.1002/adbi.201700083] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
To more accurately study the complex mechanisms behind cancer invasion, progression, and response to treatment, researchers require models that replicate both the multicellular nature and 3D stromal environment present in an in vivo tumor. Multicellular aggregates (i.e., spheroids) embedded in an extracellular matrix mimic are a prevalent model. Recently, quantitative metrics that fully utilize the capability of spheroids are described along with conventional experiments, such as invasion into a matrix, to provide additional details and insights into the underlying cancer biology. The review begins with a discussion of the salient features of the tumor microenvironment, introduces the early work on non-embedded spheroids as tumor models, and then concentrates on the successes achieved with the study of embedded spheroids. Examples of studies include cell movement, drug response, tumor cellular heterogeneity, stromal effects, and cancer progression. Additionally, new methodologies and those borrowed from other research fields (e.g., vascularization and tissue engineering) are highlighted that expand the capability of spheroids to aid future users in designing their cancer-related experiments. The convergence of spheroid research among the various fields catalyzes new applications and leads to a natural synergy. Finally, the review concludes with a reflection and future perspectives for cancer spheroid research.
Collapse
Affiliation(s)
- Kristie M. Tevis
- Departments of Biomedical Engineering, Chemistry, and Medicine, Metcalf Center for Science and Engineering, Boston University, Boston, MA 02215
| | - Yolonda L. Colson
- Division of Thoracic Surgery, Department of Surgery, Brigham and Women’s Hospital, Boston, MA 02215
| | - Mark W. Grinstaff
- Departments of Biomedical Engineering, Chemistry, and Medicine, Metcalf Center for Science and Engineering, Boston University, Boston, MA 02215
| |
Collapse
|
26
|
Gayan S, Teli A, Dey T. Inherent aggressive character of invasive and non-invasive cells dictates the in vitro migration pattern of multicellular spheroid. Sci Rep 2017; 7:11527. [PMID: 28912559 PMCID: PMC5599661 DOI: 10.1038/s41598-017-10078-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 07/21/2017] [Indexed: 11/24/2022] Open
Abstract
Cellular migration, a process relevant to metastasis, is mostly studied in the conventional 2D condition. However, cells cultured in the 3D condition assumed to mimic the in vivo conditions better. The current study is designed to compare an invasive and non-invasive adenocarcinoma cell with an invasive fibrosarcoma cell to understand the migration pattern of the multicellular spheroid. It is observed that conventional haplotaxis, chemotactic and pseudo-3D migration assay cannot distinguish between the invasive and non-invasive cells conclusively under 2D condition. Invasive spheroids migrate rapidly in sprouting assay in comparison to non-invasive spheroids. Effects of cytochalasin B, marimastat and blebbistatin are tested to determine the influence of different migration modality namely actin polymerization, matrix metalloprotease and acto-myosin in both culture conditions. Altered mRNA profile of cellular migration related genes (FAK, Talin, Paxillin, p130cas and Vinculin) is observed between 2D and 3D condition followed by the changed expression of matrix metallo proteases. A distinct difference is observed in distribution and formation of focal adhesion complex under these culture conditions. This study demonstrates the efficacy of multicellular spheroids in identifying the intrinsic aggressive behavior of different cell lines as a proof of concept and recognizes the potential of spheroids as a migration model.
Collapse
Affiliation(s)
- Sukanya Gayan
- Institute of Bioinformatics and Biotechnology,Savitribai Phule Pune University, Pune, India
| | - Abhishek Teli
- Institute of Bioinformatics and Biotechnology,Savitribai Phule Pune University, Pune, India
| | - Tuli Dey
- Institute of Bioinformatics and Biotechnology,Savitribai Phule Pune University, Pune, India.
| |
Collapse
|
27
|
Gettler BC, Zakhari JS, Gandhi PS, Williams SK. Formation of Adipose Stromal Vascular Fraction Cell-Laden Spheroids Using a Three-Dimensional Bioprinter and Superhydrophobic Surfaces. Tissue Eng Part C Methods 2017; 23:516-524. [PMID: 28665236 DOI: 10.1089/ten.tec.2017.0056] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The therapeutic infusion of adipose-derived stromal vascular fraction (SVF) cells for the treatment of multiple diseases, has progressed to numerous human clinical trials; however, the often poor retention of the cells following implantation remains a common drawback of direct cell injection. One solution to cellular retention at the injection site has been the use of biogels to encapsulate cells within a microenvironment before and upon implantation. The current study utilized three-dimensional bioprinting technology to evaluate the ability to form SVF cell-laden spheroids with collagen I as a gel-forming biomatrix. A superhydrophobic surface was created to maintain the bioprinted structures in a spheroid shape. A hydrophilic disc was printed onto the hydrophobic surface to immobilize the spheroids during the gelation process. Conditions for the automated rapid formation of SVF cell-laden spheroids were explored, including time/pressure relationships for spheroid extrusion during bioprinting. The formed spheroids maintain SVF viability in both static culture and dynamic spinner culture. Spheroids also undergo a time-dependent contraction with the retention of angiogenic sprout phenotype over the 14-day culture period. The use of a biphilic surface exhibiting both superhydrophobicity to maintain the spheroid shape and a hydrophilicity to immobilize the spheroid during gel formation produces SVF cell-laden spheroids that can be immediately transplanted for therapeutic applications.
Collapse
Affiliation(s)
- Brian C Gettler
- Cardiovascular Innovation Institute, University of Louisville , Louisville, Kentucky
| | - Joseph S Zakhari
- Cardiovascular Innovation Institute, University of Louisville , Louisville, Kentucky
| | - Piyani S Gandhi
- Cardiovascular Innovation Institute, University of Louisville , Louisville, Kentucky
| | - Stuart K Williams
- Cardiovascular Innovation Institute, University of Louisville , Louisville, Kentucky
| |
Collapse
|
28
|
Cisneros Castillo LR, Oancea AD, Stüllein C, Régnier-Vigouroux A. A Novel Computer-Assisted Approach to evaluate Multicellular Tumor Spheroid Invasion Assay. Sci Rep 2016; 6:35099. [PMID: 27731418 PMCID: PMC5059692 DOI: 10.1038/srep35099] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 09/26/2016] [Indexed: 11/23/2022] Open
Abstract
Multicellular tumor spheroids (MCTSs) embedded in a matrix are re-emerging as a powerful alternative to monolayer-based cultures. The primary information gained from a three-dimensional model is the invasiveness of treatment-exposed MCTSs through the acquisition of light microscopy images. The amount and complexity of the acquired data and the bias arisen by their manual analysis are disadvantages calling for an automated, high-throughput analysis. We present a universal algorithm we developed with the scope of being robust enough to handle images of various qualities and various invasion profiles. The novelty and strength of our algorithm lie in: the introduction of a multi-step segmentation flow, where each step is optimized for each specific MCTS area (core, halo, and periphery); the quantification through the density of the two-dimensional representation of a three-dimensional object. This latter offers a fine-granular differentiation of invasive profiles, facilitating a quantification independent of cell lines and experimental setups. Progression of density from the core towards the edges influences the resulting density map thus providing a measure no longer dependent on the sole area size of MCTS, but also on its invasiveness. In sum, we propose a new method in which the concept of quantification of MCTS invasion is completely re-thought.
Collapse
|