This work is supported by the bequest of Moshe Shimon and Judith Weisbrodt.

1. HMCA Plate Embossing
NOTE: The complete process for the design and fabrication of polydimethylsiloxane (PDMS) stamp and HMCA imaging plate used in this protocol is described in detail in our previous articles15,16. The PDMS stamp (negative shape) is used to emboss the HMCA (positive shape) which consists of approximately 450 MCs per well (Figure 1A). As demonstrated in Figure 1B</stro...

<ol>
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Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-Content+Monitoring+of+Drug+Effects+in+a+3D+Spheroid+Model.">High-Content Monitoring of Drug Effects in a 3D Spheroid Model.</a> Frontiers in Oncology. 7, 293 (2017).</li><li>Evensen, N. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+a+High-Throughput+Three-Dimensional+Invasion+Assay+for+Anti-Cancer+Drug+Discovery.">Development of a High-Throughput Three-Dimensional Invasion Assay for Anti-Cancer Drug Discovery.</a> PLoS ONE. 8 (12), e82811 (2013).</li><li>Aw Yong, K. M., Li, Z., Merajver, S. D., Fu, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tracking+the+tumor+invasion+front+using+long-term+fluidic+tumoroid+culture.">Tracking the tumor invasion front using long-term fluidic tumoroid culture.</a> Scientific Reports. 7 (1), 10784 (2017).</li><li>Mi, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microfluidic+co-culture+system+for+cancer+migratory+analysis+and+anti-metastatic+drugs+screening.">Microfluidic co-culture system for cancer migratory analysis and anti-metastatic drugs screening.</a> Scientific Reports. 6 (1), 35544 (2016).</li><li>Chung, S., Sudo, R., Mack, P. J., Wan, C. -. R., Vickerman, V., Kamm, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+migration+into+scaffolds+under+co-culture+conditions+in+a+microfluidic+platform.">Cell migration into scaffolds under co-culture conditions in a microfluidic platform.</a> Lab on a chip. 9 (2), 269-275 (2009).</li><li>Krakhmal, N. V., Zavyalova, M. V., Denisov, E. V., Vtorushin, S. V., Perelmuter, V. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cancer+Invasion:+Patterns+and+Mechanisms.">Cancer Invasion: Patterns and Mechanisms.</a> Acta naturae. 7 (2), 17-28 (2015).</li><li>Lintz, M., Mu&#241;oz, A., Reinhart-King, C. 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N., Ahmad, N., Mukhtar, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fisetin:+a+dietary+antioxidant+for+health+promotion.">Fisetin: a dietary antioxidant for health promotion.</a> Antioxidants &amp; redox signaling. 19 (2), 151-162 (2013).</li><li>Lee, G. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Networked+concave+microwell+arrays+for+constructing+3D+cell+spheroids.">Networked concave microwell arrays for constructing 3D cell spheroids.</a> Biofabrication. 10 (1), 15001 (2017).</li><li>Vinci, M., Box, C., Eccles, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+(3D)+tumor+spheroid+invasion+assay.">Three-dimensional (3D) tumor spheroid invasion assay.</a> Journal of visualized experiments: JoVE. (99), e52686 (2015).</li><li>Toh, Y. -. C., Raja, A., Yu, H., van Noort, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+3D+Microfluidic+Model+to+Recapitulate+Cancer+Cell+Migration+and+Invasion.">A 3D Microfluidic Model to Recapitulate Cancer Cell Migration and Invasion.</a> Bioengineering. 5 (2), 29 (2018).</li><li>Sugimoto, M., Kitagawa, Y., Yamada, M., Yajima, Y., Utoh, R., Seki, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Micropassage-embedding+composite+hydrogel+fibers+enable+quantitative+evaluation+of+cancer+cell+invasion+under+3D+coculture+conditions.">Micropassage-embedding composite hydrogel fibers enable quantitative evaluation of cancer cell invasion under 3D coculture conditions.</a> Lab on a Chip. 18 (9), 1378-1387 (2018).</li><li>Yamamoto, S., Hotta, M. M., Okochi, M., Honda, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+Vascular+Formed+Endothelial+Cell+Network+on+the+Invasive+Capacity+of+Melanoma+Using+the+In+Vitro+3D+Co-Culture+Patterning+Model.">Effect of Vascular Formed Endothelial Cell Network on the Invasive Capacity of Melanoma Using the In Vitro 3D Co-Culture Patterning Model.</a> PLoS ONE. 9 (7), e103502 (2014).</li><li>Lee, S. -. H., Moon, J. J., West, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+micropatterning+of+bioactive+hydrogels+via+two-photon+laser+scanning+photolithography+for+guided+3D+cell+migration.">Three-dimensional micropatterning of bioactive hydrogels via two-photon laser scanning photolithography for guided 3D cell migration.</a> Biomaterials. 29 (20), 2962-2968 (2008).</li><li>Gschwind, A., Zwick, E., Prenzel, N., Leserer, M., Ullrich, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+communication+networks:+epidermal+growth+factor+receptor+transactivation+as+the+paradigm+for+interreceptor+signal+transmission.">Cell communication networks: epidermal growth factor receptor transactivation as the paradigm for interreceptor signal transmission.</a> Oncogene. 20 (13), 1594-1600 (2001).</li><li>Jiang, K., Dong, C., Xu, Y., Wang, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microfluidic-based+biomimetic+models+for+life+science+research.">Microfluidic-based biomimetic models for life science research.</a> RSC Advances. 6 (32), 26863-26873 (2016).</li><li>Mason, B. N., Starchenko, A., Williams, R. M., Bonassar, L. J., Reinhart-King, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tuning+three-dimensional+collagen+matrix+stiffness+independently+of+collagen+concentration+modulates+endothelial+cell+behavior.">Tuning three-dimensional collagen matrix stiffness independently of collagen concentration modulates endothelial cell behavior.</a> Acta biomaterialia. 9 (1), 4635-4644 (2013).</li><li>Raub, C. B., Putnam, A. J., Tromberg, B. J., George, S. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Predicting+bulk+mechanical+properties+of+cellularized+collagen+gels+using+multiphoton+microscopy.">Predicting bulk mechanical properties of cellularized collagen gels using multiphoton microscopy.</a> Acta Biomaterialia. 6 (12), 4657-4665 (2010).</li><li>Paszek, M. 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It is well documented that living organisms, characterized by their complex 3D multicellular organization are quite distinct from the commonly used 2D monolayer cultured cells, emphasizing the crucial need to use cellular models which better mimic the functions and processes of the living organism for drug screening. Recently, multicellular spheroids, organotypic cultures, organoids and organs-on-a-chip have been introduced8 for the use in standardized drug discovery. However, the 3D multicellular...

Cancer death is attributed mainly to the dissemination of metastatic cells to distant locations. Many efforts in cancer treatment focus on targeting or preventing the formation of metastatic colonies and progression of systemic metastatic disease1. Cancer cell migration is a crucial step in the tumor metastasis process, thus, the research of the cancer invasion cascade is very important and a prerequisite to finding anti-metastatic therapeutics.
The use of animal models as tools for studying metastatic disease has been found to be very expensive and not always representative of the tumor in humans. Moreover, the extracellular microenvironment topology, mechanics and composition strongly affect cancer cell behavior2. Since in vivo models inherently lack the ability to separate and control such specific parameters which contribute to cancer invasion and metastasis, there is a need for controllable biomimetic in vitro models.
In order to metastasize to distant organs, cancer cells must exhibit migratory and invasive phenotypic traits which can be targeted for therapy. However, since most in vitro cancer models do not mimic the actual features of solid tumors3, it is very challenging to detect physiologically relevant phenotypes. In addition, the phenotypic heterogeneity that exists within the tumor, dictates the need for analyzing tumor migration at single-element resolution in order to discover phenotype-directed therapies, for instance, by targeting the metastasis-initiating cell population within heterogeneous tumors4.
The study of cell motility and collective migration is primarily conducted in monolayer cultures of epithelial cells on homogeneous planar surfaces. These conventional cellular models for cancer cell migration are based on the population analysis of individual cells invading through the membranes and ECM components5, but in such systems, the intrinsic differences between individual cells cannot be studied. Generating 3D spheroids either via scaffolds or in scaffold-free micro-structures is considered as a superior means to study the tumor cell growth and cancer invasion6,7,8. However, most 3D systems are not suitable to high throughput formats, and inter-spheroid interaction cannot usually be achieved since isolated individual spheroids are generated in each micro-well9. Recent studies involving the cancer migration are based on microfluidic devices3,10,11,12, however, these sophisticated microfluidic tools are difficult to produce and cannot be used for high throughput screening (HTS) of anti-invasive drugs.
Two main phenotypes, collective and individual cell migration, which play a role in tumor cells overcoming the ECM barrier and invading neighboring tissue, have been demonstrated13,14, each displaying distinct morphological characteristics, biochemical, molecular and genetic mechanisms. In addition, two forms of migrating tumor cells, fibroblast-like and amoeboid, are observed in each phenotype. Since both, invasion phenotypes and migration modes, are mainly defined by morphological properties, there is a need for cellular models that enable imaging-based detection and examination of all forms of tumor invasion and migrating cells.
The overall goal of the current method is to provide a simple and reproducible biomimetic 3D in vitro cell-based system for the analysis of invasion capacity in large populations of tumor spheroids. Here, we introduce the HMCA-based 6-well imaging plate for the research of tumor invasion and anti-metastatic therapy. The technology enables the formation of large numbers of uniform 3D tumor spheroids (450 per well) in a hydrogel micro-chambers (MC) structure. Various ECM components are added to the spheroid array to enable the invasion of the cells into the surrounding environment. Invasion process is continuously monitored by short- and long-term observation of the same individual spheroids/invading cells and facilitates morphological characterization, fluorescent staining and retrieval of specific spheroids at any point. Since numerous spheroids share space and medium, interaction via soluble molecules between individual spheroids and their impact on one another is possible. Semi-automatic image analysis is performed by using in-house MATLAB code which enables faster and more efficient collection of large amount of data. The platform facilitates accurate, simultaneous measurement of numerous spheroids/invading cells in a time-efficient manner, allowing medium throughput screening of anti-invasion drugs.

<table>
	<tbody>
		<tr>
			<td>6 Micro-well Glass Bottom Plates with 14 mm micro-well #1.5 cover glass</td>
			<td>Cellvis</td>
			<td>P06-14-1.5-N</td>
			<td>Commercial glass bottom plates which are used for HMCA embossing</td>
		</tr>
		<tr>
			<td>UltraPure Low Melting Point Agarose</td>
			<td>Invitrogen</td>
			<td>16520100</td>
			<td>A solution of 6% agarose is warmed up to 80&#176;C before use, a solution of 1% agarose is warmed to 37&#176;C</td>
		</tr>
		<tr>
			<td>Trypsin EDTA solution B</td>
			<td>Biological Industries</td>
			<td>03-052-1A</td>
			<td>Warmed to 37&#176;C before use</td>
		</tr>
		<tr>
			<td>DMEM medium, high glucose</td>
			<td>Biological Industries</td>
			<td>01-055-1A</td>
			<td>Warmed to 37&#176;C before use</td>
		</tr>
		<tr>
			<td>Special Newborn Calf Serum (NBCS)</td>
			<td>Biological Industries</td>
			<td>04-122-1A</td>
			<td>Heat Inactivated</td>
		</tr>
		<tr>
			<td>DPBS (10X), no calcium, no magnesium</td>
			<td>Biological Industries</td>
			<td>02-023-5A</td>
			<td>Kept on ice before use</td>
		</tr>
		<tr>
			<td>NaOH, anhydrous</td>
			<td>Sigma-Aldrich</td>
			<td>S5881-500G</td>
			<td>Used for the preparation of 1M NaOH solution</td>
		</tr>
		<tr>
			<td>Cultrex Type I collagen from rat tail, 5mg/ml</td>
			<td>Trevigen</td>
			<td>3440-100-01</td>
			<td>Kept on ice before use</td>
		</tr>
		<tr>
			<td>Hyaluronic acid sodium salt</td>
			<td>Sigma-Aldrich</td>
			<td>H5542-10MG</td>
			<td>Kept on ice before use</td>
		</tr>
		<tr>
			<td>Fisetin</td>
			<td>Sigma-Aldrich</td>
			<td>F505-100MG</td>
			<td>Added to the culture medium, invasion inhibitor</td>
		</tr>
		<tr>
			<td>DETA/NO</td>
			<td>Enzo Life Sciences</td>
			<td>alx-430-014-m005</td>
			<td>Added to the culture medium, nitric oxide donor</td>
		</tr>
		<tr>
			<td>PI</td>
			<td>Sigma-Aldrich</td>
			<td>P4170</td>
			<td>Used at very low concenrtation without the need for washing</td>
		</tr>
		<tr>
			<td>Dymax 5000-EC UV flood lamp complete system with light shield &#38; Dymax 400 Watt EC power supply</td>
			<td>Dymax Corporation</td>
			<td>PN 39823</td>
			<td>Used for HMCA plate sterilization by UV</td>
		</tr>
		<tr>
			<td>Inverted IX81 microscope</td>
			<td>Olympus</td>
			<td></td>
			<td>Used for automatic image acquisition</td>
		</tr>
		<tr>
			<td>Incubator for microscope</td>
			<td>Life Imaging Services</td>
			<td></td>
			<td>Essential for time lapse experiments with image acquisition, pre adjusted to 37&#176;C, 5% CO2 and keeping a humidified atmosphere</td>
		</tr>
		<tr>
			<td>Sub-micron motorized stage type SCAN-IM</td>
			<td>Marzhauser Wetzlar GmbH</td>
			<td></td>
			<td>Used to predetermine image acquisition areas, for automatic image acquisition</td>
		</tr>
		<tr>
			<td>14-bit, ORCA II C4742-98 cooled camera</td>
			<td>Hamamatsu Photonics</td>
			<td></td>
			<td>Highly sensitive, used for imaging</td>
		</tr>
		<tr>
			<td>Fluorescent filter cube for PI detection</td>
			<td>Chroma Technology Corporation</td>
			<td></td>
			<td>Filter cube specifications: excitation filter 530-550 nm, dichroic mirror 565 nm long pass and emission filter 600-660 nm</td>
		</tr>
		<tr>
			<td>The Olympus Cell^P operating software</td>
			<td>Olympus</td>
			<td></td>
			<td>Software used to control microscope, motorized stage, camera and image acquisition</td>
		</tr>
		<tr>
			<td>Matlab R2014B analysis software</td>
			<td>Mathworks</td>
			<td></td>
			<td>Used to develop in house graphic user interface for image analysis</td>
		</tr>
		<tr>
			<td>Excel software</td>
			<td>Microsoft</td>
			<td></td>
			<td>Used for data management, calculation, plot creation and statistics</td>
		</tr>
	</tbody>
</table>

analysis of cancer cell invasion and anti-metastatic drug screening using hydrogel micro-chamber array (hmca)-based plates

Cancer metastasis is known to cause 90% of cancer lethality. Metastasis is a multistage process which initiates with the penetration/invasion of tumor cells into neighboring tissue. Thus, invasion is a crucial step in metastasis, making the invasion process research and development of anti-metastatic drugs, highly significant. To address this demand, there is a need to develop 3D in vitro models which imitate the architecture of solid tumors and their microenvironment most closely to in vivo state on one hand, but at the same time be reproducible, robust and suitable for high yield and high content measurements. Currently, most invasion assays lean on sophisticated microfluidic technologies which are adequate for research but not for high volume drug screening. Other assays using plate-based devices with isolated individual spheroids in each well are material consuming and have low sample size per condition. The goal of the current protocol is to provide a simple and reproducible biomimetic 3D cell-based system for the analysis of invasion capacity in large populations of tumor spheroids. We developed a 3D model for invasion assay based on HMCA imaging plate for the research of tumor invasion and anti-metastatic drug discovery. This device enables the production of numerous uniform spheroids per well (high sample size per condition) surrounded by ECM components, while continuously and simultaneously observing and measuring the spheroids at single-element resolution for medium throughput screening of anti-metastatic drugs. This platform is presented here by the production of HeLa and MCF7 spheroids for exemplifying single cell and collective invasion. We compare the influence of the ECM component hyaluronic acid (HA) on the invasive capacity of collagen surrounding HeLa spheroids. Finally, we introduce Fisetin (invasion inhibitor) to HeLa spheroids and nitric oxide (NO) (invasion activator) to MCF7 spheroids. The results are analyzed by in-house software which enables semi-automatic, simple and fast analysis which facilitates multi-parameter examination.

The unique HMCA imaging plate is used for the invasion assay of 3D tumor spheroids. The entire assay, beginning with the spheroid formation and ending with the invasion process and additional manipulations, is performed within the same plate. For the spheroid formation, HeLa cells are loaded into the array basin and settle in the hydrogel MCs by gravity. The hydrogel MCs, which have non-adherent/low attachment characteristics, facilitate the cell-cell interaction and the formation of 3D t...

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Analysis of Cancer Cell Invasion and Anti-metastatic Drug Screening Using Hydrogel Micro-chamber Array HMCA-based Plates

A HMCA-based imaging plate is presented for invasion assay performance. This plate facilitates the formation of three-dimensional (3D) tumor spheroids and the measurement of cancer cell invasion into the extracellular matrix (ECM). The invasion assay quantification is achieved by semi-automatic analysis.

Analysis of Cancer Cell Invasion and Anti-metastatic Drug Screening Using Hydrogel Micro-chamber Array (HMCA)-based Plates

Cancer metastasis is known to cause 90% of cancer lethality. Metastasis is a multistage process which initiates with the penetration/invasion of tumor ...

The goal of this simple reproducible biomimetic 3D cell-based system is to facilitate invasion capacity analysis in large population of tumor spheroid for anti-metastatic drug screening. The main advantage of our hydrogel micro-chamber array is that it allows the production of a large number of uniform spheroids that populate the same focal plane per well. The spheroid position is retained due to the hydrogel micro-chamber array structure even after extracellular matrix addition, facilitating the accurate continuous monitoring of the spheroids and the invasion process.Further, the morphological characterization and fluorescent staining of numerous spheroids and invading cells can be performed in situ and analyzed at a single-element resolution in a time-efficient manner. Demonstrating the hydrogel micro-chamber array six-well imaging plate production procedure will be Maria Sobolev from our laboratory. To prepare the hydrogel micro-chamber array plates, first preheat six polydimethylsiloxane, or PDMS, stamps to 70 degrees Celsius, and place a six-well, glass-bottom plate on a dry bath pre-heated to 75 degrees Celsius for several minutes.When the plate is warm, pour a 400-microliter drop of pre-heated low-melting agarose onto the bottom of each well of the six-well plate, and gently place one stamp over each drop. Allow the setup to cool for five to 10 minutes at room temperature, followed by 20 minutes at four degrees Celsius for full agarose gelation. When the agarose has solidified, gently peel off the PDMS from each well, leaving the agarose gels patterned with micro-chambers.After allowing the UV lamp to reach its highest intensity, place the embossed plate in the light curing system for three minutes, and fill the UV-sterilized macro-wells with sterile PBS. Then, cover the plate, and wrap it with Parafilm for four-degree Celsius storage until use. To load the cells, remove the PBS from each well, and gently load 50 microliters of the cells of interest on top of each hydrogel array.After allowing the cells to settle by gravity for 15 minutes, carefully add six to eight aliquots of 500 microliters of fresh medium to the rim of the macro-well plastic bottom outside of the ring and hydrogel array. Incubate the cells for the appropriate time period at 37 degrees Celsius and 5%carbon dioxide with humidity for the formation of spheroids. Then, transfer the spheroids into a biosafety hood on ice for 10 minutes.When the plate has cooled, lean a pipette tip on the edge of the macro-well plastic bottom next to the hydrogel array, and remove all of the medium from around the array. Then, remove the medium from the array tank, lean a gel-loading pipette tip on the edge of the array tank very carefully, taking care not to disturb the micro-chambers and spheroids. Next, use a pre-frozen, fine pipette tip to add two aliquots of 150 microliters of the collagen mixture of interest at the edge of the array one at a time, releasing the mixture slowly to avoid spheroid dislocation.After the second round of collagen has been added to each well, return the spheroids to the incubator for one hour for full gelation of the extracellular matrix. When the matrix has solidified, add 400 microliters of pre-warmed 1%low-melting agarose on top of the gel, and incubate the plate, covered at room temperature, for five to seven minutes, before cooling for two minutes at four degrees Celsius for agarose gelation. Then, leaning the pipette on the edge of the macro-well plastic bottom, gently add two milliliters of complete medium to each well.To perform an invasion assay, load the hydrogel micro-chamber array plate onto a motorized inverted microscope stage equipped with a 37-degree Celsius and 5%carbon dioxide incubator with a humidified atmosphere, and use a four or 10x objective to pre-determine the positions for the image acquisition in each well so that the entire array area will be assessed. Then, acquire bright-field images every two to fours hours for a total of 24 to 72 hours to track the cell invasion from the spheroid body into the surrounding extracellular matrix. At the end of the image acquisition, export the time-lapse images from the image acquisition software for saving in a tagged image file format to a dedicated folder.Next, open the graphic user interface, and click Load Bright Field. Adjust the segmentation parameters of the image to achieve a precise segmentation of the spheroids and their invasion areas, and click Region Of Interest Segmentation to create a border around each spheroid. If the automatic segmentation is incorrect, press Delete or Add, and make the appropriate corrections manually.Click Tracking to number the spheroids in each of the time-lapse images. Then, click Measurement to generate a spreadsheet with all of the parameters, and save the spreadsheet in an appropriate format for data processing and statistical analysis. To examine the influence of hyaluronic acid on the spontaneous HeLa spheroid invasion process, in this experiment, two-day-matured spheroids were covered with collagen and hyaluronic acid mixture solution and compared to two-day-matured spheroids covered with collagen solution alone.After 50 hours of incubation, the spheroids embedded in collagen and hyaluronic acid demonstrated a lower cell dispersion into the surrounding extracellular matrix compared to the spheroids embedded in collagen alone. Indeed, analysis of the invasion area kinetics over time for 99 spheroids at single-spheroid resolution clearly indicates that the addition of hyaluronic acid to the collagen inhibits cell dispersion out of the spheroid, resulting in smaller invasion areas. Treatment of the HeLa spheroid culture with a bioactive flavonoid with cyto-and migrastatic properties for 24 hours results in an inhibited cell dispersion around the spheroids compared to non-treated HeLa spheroids.Indeed, analysis of the invasion areas of 488 spheroids at the end of the experiment revealed a significant inhibition after treatment with as little as 10 micromolar of the drug. Due to the low attachment characteristic of the hydrogel, this micro-chamber-based technology facilitate the formation of spheroid even in instances of very few cells. This is especially advantage in valuable limited cancer stem-like or patient-derived primary cell samples.The hydrogel micro-chamber imaging plate allows analysis of the exact spatial location of the spheroids during long-term experiments for the evaluation of the invasion process at the single-element level and provides a high degree of statistical robustness and accuracy. Future applications of this methodology include side-by-side multi-cell culturing of tumor and stromal cells in different regions within the macro-well and the retrieval of individual spheroids for downstream molecular analysis.

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JoVE Journal

Cancer Research

8.9K visualizações.  Bar-Ilan University. O objetivo deste simples sistema biomimético baseado em células 3D é facilitar a análise da capacidade de invasão em grande população de esferoide tumoral para rastreamento de drogas anti-metastáticas. A principal vantagem do nosso conjunto de micro-câmaras de hidrogel é que permite a produção de um grande número de esferoides uniformes que povoam o mesmo plano focal por poço. A posição esferoide é mantida devido à estrutura da matriz de microcervejas de hidrogel mesmo após...