Name: three-dimensional culture assay to explore cancer cell invasiveness and satellite tumor formation
Uploaded: 2016-08-18T15:00:00
Description: Watch this Scientific Journal Video about Three-Dimensional Culture Assay to Explore Cancer Cell Invasiveness and Satellite Tumor Formation at JoVE.com

Work partially funded by Prostate Cancer Canada (grant # D2014-4 to SG and CJD) and the Canadian Institutes of Health Research (grant # MOP-111069 to SG). We would like to thank Dr. Richard Poulin for editorial assistance and Mrs. Chanel Dupont for technical assistance.

NOTE: No ethics consideration since animal and human cancer cells were purchased or kindly provided to us.
1. Making Collagen Plugs (Pseudo-primary Tumor)
<ol>
	<li>Prepare a collagen dispersion. Type I collagen from rat tail tendons (RTT) can be either extracted and sterilized as previously reported17, or purchased. Disperse freeze-dried RTT collagen (3.25-3.50 mg/ml in 0.02 N acetic acid) using a blender (high-speed setting; five 2 min runs) for a uniform mixing.</li>
	<li>Harvest (trypsin-EDTA, usu...

<ol>
	<li>Alizadeh, A. M., Shiri, S., Farsinejad, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Metastasis+review:+from+bench+to+bedside.">Metastasis review: from bench to bedside.</a> Tumour Biol. 35 (9), 8483-8523 (2014).</li><li>Roudsari, L. C., 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=Studying+the+influence+of+angiogenesis+in+in+vitro+cancer+model+systems.">Studying the influence of angiogenesis in in vitro cancer model systems.</a> Adv Drug Deliv Rev. , (2016).</li><li>Bill, R., Christofori, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+relevance+of+EMT+in+breast+cancer+metastasis:+Correlation+or+causality.">The relevance of EMT in breast cancer metastasis: Correlation or causality.</a> FEBS Lett. 589 (14), 1577-1587 (2015).</li><li>Kimlin, L. C., Casagrande, G., Virador, 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=In+Vitro+Three-Dimensional+(3D)+Models+in+Cancer+Research:+an+Update.">In Vitro Three-Dimensional (3D) Models in Cancer Research: an Update.</a> Mol Carcinog. 52 (3), 167-182 (2013).</li><li>Obenauf, A. C., Massagu&#233;, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surviving+at+a+Distance+Organ-Specific+Metastasis.">Surviving at a Distance Organ-Specific Metastasis.</a> Trends Cancer. 1 (1), 76-91 (2015).</li><li>Sykes, J. A., Fogh, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Separation+of+Tumor+Cells+from+Fibroblasts.">Separation of Tumor Cells from Fibroblasts.</a> Human Tumor Cells In Vitro. 1, 1-22 (1975).</li><li>Lang, S. H., Stark, M., Collins, A., Paul, A. B., Stower, M. J., Maitland, N. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+Prostate+Epithelial+Morphogenesis+in+Response+to+Stroma+and+Three-Dimensional+Matrigel+Culture.">Experimental Prostate Epithelial Morphogenesis in Response to Stroma and Three-Dimensional Matrigel Culture.</a> Cell Growth Differ. 12 (12), 631-640 (2001).</li><li>Debnath, J., Muthuswamy, S. K., Brugge, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morphogenesis+and+Oncogenesis+of+MCF-10A+Mammary+Epithelial+Acini+Grown+In+Three-Dimensional+Basement+Membrane+Cultures.">Morphogenesis and Oncogenesis of MCF-10A Mammary Epithelial Acini Grown In Three-Dimensional Basement Membrane Cultures.</a> Methods. 30 (3), 256-268 (2003).</li><li>Shaw, L. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tumor+cell+invasion+assays.">Tumor cell invasion assays.</a> Methods Mol. Biol. 294, 97-105 (2005).</li><li>Nelson, C. M., Bissell, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modeling+Dynamic+Reciprocity:+Engineering+Three-Dimensional+Culture+Models+of+Breast+Architecture,+Function,+and+Neoplastic+Transformation.">Modeling Dynamic Reciprocity: Engineering Three-Dimensional Culture Models of Breast Architecture, Function, and Neoplastic Transformation.</a> Semin Cancer Biol. 15 (5), 342-352 (2005).</li><li>Hedlund, T. E., Duke, R. C., Miller, G. J. <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+Spheroid+Cultures+of+Human+Prostate+Cancer+Cell+Lines.">Three-Dimensional Spheroid Cultures of Human Prostate Cancer Cell Lines.</a> Prostate. 41 (3), 154-165 (1999).</li><li>Le, V. M., Lang, M. D., Shi, W. B., Liu, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Collagen-Based+Multicellular+Tumor+Spheroid+Model+for+Evaluation+of+the+Efficiency+of+Nanoparticle+Drug+Delivery.">A Collagen-Based Multicellular Tumor Spheroid Model for Evaluation of the Efficiency of Nanoparticle Drug Delivery.</a> Artif. Cells Nanomed Biotechnol. 15, 1-5 (2014).</li><li>Neto, A. I., 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=A+Novel+Hanging+Spherical+Drop+System+for+the+Generation+of+Cellular+Spheroids+and+High+Throughput+Combinatorial+Drug+Screening.">A Novel Hanging Spherical Drop System for the Generation of Cellular Spheroids and High Throughput Combinatorial Drug Screening.</a> Biomater Sci. 3 (4), 581-585 (2015).</li><li>Janvier, R., Sourla, A., Koutsilieris, M., Doillon, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stromal+Fibroblasts+are+Required+for+PC-3+Human+Prostate+Cancer+Cells+to+Produce+Capillary-like+Formation+of+Endothelial+Cells+in+a+Three-dimensional+Co-culture+System.">Stromal Fibroblasts are Required for PC-3 Human Prostate Cancer Cells to Produce Capillary-like Formation of Endothelial Cells in a Three-dimensional Co-culture System.</a> Anticancer Res. 17 (3A), 1551-1557 (1997).</li><li>Doillon, C. J., Gagnon, E., Paradis, R., Koutsilieris, M. <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+Culture+System+as+a+Model+for+Studying+Cancer+Cell+Invasion+Capacity+and+Anticancer+Drug+Sensitivity.">Three-dimensional Culture System as a Model for Studying Cancer Cell Invasion Capacity and Anticancer Drug Sensitivity.</a> Anticancer Res. 24 (4), 2169-2177 (2004).</li><li>Gobeil, S., Zhu, X., Doillon, C. J., Green, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Genome-Wide+shRNA+Screen+Identifies+GAS1+as+a+Novel+Melanoma+Metastasis+Suppressor+Gene.">A Genome-Wide shRNA Screen Identifies GAS1 as a Novel Melanoma Metastasis Suppressor Gene.</a> Genes Dev. 22 (21), 2932-2940 (2008).</li><li>Rajan, N., Habermehl, J., Cot&#233;, M. F., Doillon, C. J., Mantovani, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+Of+Ready-To-Use,+Storable+And+Reconstituted+Type+I+Collagen+From+Rat+Tail+Tendon+For+Tissue+Engineering+Applications.">Preparation Of Ready-To-Use, Storable And Reconstituted Type I Collagen From Rat Tail Tendon For Tissue Engineering Applications.</a> Nat Protoc. 1 (6), 2753-2758 (2007).</li><li>Horie, M., 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=Characterization+of+Human+Lung+Cancer-associated+Fibroblasts+in+Three-dimensional+In+Vitro+Co-culture+Model.">Characterization of Human Lung Cancer-associated Fibroblasts in Three-dimensional In Vitro Co-culture Model.</a> Biochem Biophys Res Commun. 423 (1), 158-163 (2012).</li><li>Banyard, J., 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=Identification+of+Genes+Regulating+Migration+and+Invasion+Using+a+New+Model+of+Metastatic+Prostate+Cancer.">Identification of Genes Regulating Migration and Invasion Using a New Model of Metastatic Prostate Cancer.</a> BMC Cancer. 30 (14), 387 (2014).</li><li>Palumbo, J. S., Degen, 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=Fibrinogen+and+Tumor+Cell+Metastasis.">Fibrinogen and Tumor Cell Metastasis.</a> Haemostasis. 31, 11-15 (2001).</li><li>Dvorak, H. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tumor+Stroma,+Tumor+Blood+Vessels,+and+Antiangiogenesis+Therapy.">Tumor Stroma, Tumor Blood Vessels, and Antiangiogenesis Therapy.</a> Cancer J. 21 (4), 237-243 (2015).</li><li>Luoto, K. R., Kumareswaran, R., Bristow, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tumor+Hypoxia+as+a+Driving+Force+in+Genetic+Instability.">Tumor Hypoxia as a Driving Force in Genetic Instability.</a> Genome Integr. 4 (1), 5 (2013).</li><li>Das, V., Bruzzese, F., Kone&#269;n&#253;, P., Iannelli, F., Budillon, A., Hajd&#250;ch, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pathophysiologically+Relevant+In+Vitro+Tumor+Models+for+Drug+Screening.">Pathophysiologically Relevant In Vitro Tumor Models for Drug Screening.</a> Drug Discov Today. 20 (7), 848-855 (2015).</li><li>Longati, P., 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=3D+Pancreatic+Carcinoma+Spheroids+Induce+a+Matrix-rich,+Chemoresistant+Phenotype+Offering+a+Better+Model+for+Drug+Testing.">3D Pancreatic Carcinoma Spheroids Induce a Matrix-rich, Chemoresistant Phenotype Offering a Better Model for Drug Testing.</a> BMC Cancer. 13 (95), (2013).</li><li>Tan, P. H., Chia, S. S., Toh, S. L., Goh, J. C., Nathanm, S. S. <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+Spatial+Configuration+of+Tumour+Cells+Confers+Resistance+to+Chemotherapy+Independent+of+Drug+Delivery.">Three-dimensional Spatial Configuration of Tumour Cells Confers Resistance to Chemotherapy Independent of Drug Delivery.</a> J Tissue Eng Regen Med. , (2013).</li><li>Koutsilieris, M., Reyes-Moreno, C., Choki, I., Sourla, A., Doillon, C., Pavlidis, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemotherapy+Cytotoxicity+of+Human+MCF-7+and+MDA-MB+231+Breast+Cancer+Cells+is+Altered+by+Osteoblast-Derived+Growth+Factors.">Chemotherapy Cytotoxicity of Human MCF-7 and MDA-MB 231 Breast Cancer Cells is Altered by Osteoblast-Derived Growth Factors.</a> Mol Med. 5 (2), 86-97 (1999).</li><li>Lang, N. R., 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=Biphasic+Response+of+Cell+Invasion+to+Matrix+Stiffness+in+Three-Dimensional+Biopolymer+Networks.">Biphasic Response of Cell Invasion to Matrix Stiffness in Three-Dimensional Biopolymer Networks.</a> Acta Biomater. 13, 61-67 (2015).</li></ol>

As an important technical footnote, it is essential that no gap is present at the interface between the central and the peripheral gels. Otherwise, it might reduce the capacity of the cells to migrate/invade the fibrin gel. A space between the collagen and the fibrin gels may form during the first 24 hr of culture if thrombin has not been appropriately diluted. It is also possible that the cell line tested might lead the collagen gel to contract during culture, thereby causing a relatively large space to form between bot...

Investigating the fundamental and biomedical characteristics of cancer cell invasion/migration and subsequent metastasis establishment is the subject of an intense research1,2. Metastasis is the ultimate stage of cancer and its clinical management remains elusive. A better understanding of metastasis at the cellular and molecular levels will enable the development of more efficient therapies3.
Several properties of metastatic cells can be explored in vitro4 including their stemness and potential to acquire a transition state (e.g., epithelioid-mesenchymal transition) to migrate and invade within and from the primary tumor5. However, the in vitro assessment of invasion/metastasis processes has been a challenge since it virtually excludes the contribution of the blood/lymphatic circulation. Organotypic cultures that embed tumor fragments in collagen gels have previously been used to monitor cancer aggressiveness. Although the complexity of tumors is preserved (e.g., the presence of non-cancerous cells), tumor fragments are exposed to limited medium diffusion, to sampling variation, and to an overgrowth of stromal cells6. An alternative method consists in growing cancer cells within components of the extracellular matrix (ECM), which mimics the three-dimensional (3D) cell environment. The proliferation of breast cancer cell lines in a collagen gel and/or a basement membrane-derived matrix is amongst the best-characterized examples of 3D cell culture. By using specific 3D cell culture environments, the disorganized assembly observed for breast cancer cells grown under standard conditions can be reversed to the spontaneous formation of mammary acini and tubular structures7-10. Furthermore, the formation of multicellular tumor spheroids derived from adenocarcinoma cancer cells congregated using different techniques (e.g., hanging drops, floating spheroids, agar embedment) now constitutes the most commonly used 3D cell culture assay11-13. However, this assay is limited by the restricted set of cancer cell lines that can form spheroids and by the short period available to study cells in these conditions.
In this visualized technique, we herein introduce a sophisticated 3D cell culture assay where cancer cells of interest are embedded in a collagen gel to allow the in vitro formation of a pseudo-primary tumor that can be alternatively coated with a basement membrane-derived matrix. Once formed, the pseudo-primary tumor is then sandwiched in an acellular matrix (fibrin gel in the present case), which allows the cancer cells to cross the interface between the two matrix compartments (see Figure 1). Interestingly, secondary tumor-like structures originating from the pseudo-primary tumor along with aggressive cancer cells appear in the fibrin gel. Such a 3D culture system offers the flexibility required to investigate, for example, anticancer drugs, gene expression and cell-cell and/or cell-ECM interactions14-16.
<img alt="Figure 1" src="/files/ftp_upload/54322/54322fig1.jpg" /> 
Figure 1: Overview of the Method. Schematic summary of the method to generate the 3D cell culture system as a model for cancer studies. <a href="https://www.jove.com/files/ftp_upload/54322/54322fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Freeze-dried collagen</td>
			<td>Sigma-Aldrich</td>
			<td>C7661</td>
			<td>from rat tail tendon (soluble dispersion) or home-made (see Rajan et al., ref.#14)</td>
		</tr>
		<tr>
			<td>Fibrinogen (freeze-dried)</td>
			<td>Sigma-Aldrich&#160;</td>
			<td>F8630</td>
			<td>Type I-S, 65-85% protein with &#8805;75% of protein is clottable</td>
		</tr>
		<tr>
			<td>Thrombin</td>
			<td>EMD Chemicals Inc.</td>
			<td>605157</td>
			<td>&#160;Gibbstown, NJ; NIH units/mg dry weight&#160;</td>
		</tr>
		<tr>
			<td>Growth factor-reduced Matrigel&#160;</td>
			<td>Corning</td>
			<td>356234</td>
			<td>Previously from BD Biosciences</td>
		</tr>
		<tr>
			<td>Aprotinin</td>
			<td>Sigma-Aldrich</td>
			<td>A6279&#160;</td>
			<td>&#160;solution at 5-10TIU/ml (Trypsin Inhibitor Unit)&#160;</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>&#160;Micro-spoons</td>
			<td>Fisher Scientific</td>
			<td>2140115</td>
			<td>Fisherbrand Handi-Hold Microspatula</td>
		</tr>
		<tr>
			<td>96 well plate, round base</td>
			<td>Sarstedt</td>
			<td>3925500</td>
			<td></td>
		</tr>
		<tr>
			<td>24 well plate</td>
			<td>Sarstedt</td>
			<td>3922</td>
			<td></td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s modified Eagle&#39;s Medium</td>
			<td>Sigma Chemical, Co.</td>
			<td>D5546</td>
			<td>DMEM</td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum</td>
			<td>VWR</td>
			<td>CAA15-701</td>
			<td>FBS, Canadian origin.</td>
		</tr>
		<tr>
			<td>Trypsin-EDTA</td>
			<td>Sigma Chemical, Co.</td>
			<td>T4049</td>
			<td></td>
		</tr>
		<tr>
			<td>Hank&#8217;s Balanced Salt Solution&#160;</td>
			<td>Sigma Chemical, Co.</td>
			<td>H8264</td>
			<td>HBSS</td>
		</tr>
	</tbody>
</table>

three-dimensional culture assay to explore cancer cell invasiveness and satellite tumor formation

Mammalian cell culture in monolayers is widely used to study various physiological and molecular processes. However, this approach to study growing cells often generates unwanted artifacts. Therefore, cell culture in a three-dimensional (3D) environment, often using extracellular matrix components, emerged as an interesting alternative due to its close similarity to the native in vivo tissue or organ. We developed a 3D cell culture system using two compartments, namely (i) a central compartment containing cancer cells embedded in a collagen gel acting as a pseudo-primary macrospherical tumor and (ii) a peripheral cell-free compartment made of a fibrin gel, i.e. an extracellular matrix component different from that used in the center, in which cancer cells can migrate (invasion front) and/or form microspherical tumors representing secondary or satellite tumors. The formation of satellite tumors in the peripheral compartment is remarkably correlated to the known aggressiveness or metastatic origin of the native tumor cells, which makes this 3D culture system unique. This cell culture approach might be considered to assess cancer cell invasiveness and motility, cell-extracellular matrix interactions and as a method to evaluate anti-cancer drug properties.

As previously mentioned, an interesting feature of this 3D cell culture assay is that cancer cells can not only migrate from the collagen plug to the adjacent fibrin gel, but also establish secondary tumors (e.g., satellite tumor-like structures). This can be directly observed with an inverted phase contrast microscope at low and high magnifications through the gel thickness, especially with a long working distance condenser (Figure 2). Using this 3D cell culture...

Watch this Scientific Journal Video about Three-Dimensional Culture Assay to Explore Cancer Cell Invasiveness and Satellite Tumor Formation at JoVE.com

Three-Dimensional Culture Assay to Explore Cancer Cell Invasiveness and Satellite Tumor Formation

Cancer cells are embedded in a collagen gel and then sandwiched in an acellular fibrin gel to generate a 3D culture system in which the invasiveness and formation of satellite tumors may be monitored.

Mammalian cell culture in monolayers is widely used to study various physiological and molecular processes. However, this approach to study growing cells ...

The overall goal of this procedure is to sandwich collagen embedded cancer cells within a fibrin gel to generate a 3D culture system for the monitoring of satellite tumor invasiveness and formation. Our 3D picture system can offer new avenues for investigating various cell and many key variants during cancer cell apoptosis or migration or to evaluate the efficacy of anti-cancer cell loss. An attractive feature of this 3D cell culture model is the ability to change the concentration of the extra cellular matrix or use another extra cellular Matrix for the assembling of the 3D system.Demonstrating the procedure will be Marie-France Cote. Research assistant, my laboratory, and Audrey Turcotte, a grad student under my supervision. Begin by blending freeze dried rat tail tendon type one collagen for five two minute mixes at the high speed setting to uniformly disperse the collagen.While the collagen is being incorporated, harvest the tumor cells of interest with the appropriate enzyme detaching solution. Followed by Trypan blue exclusion in numeration. Dilute the dissociated cells to a 50, 000 cells per plug concentration in DMEM.When the collagen is ready, quickly add 1, 250, 000 cells to the collagen solution with pipetting to homogeneously disperse the cells. Immediately dispense 200 microliters of the single cell suspension into each well of a 96 well plate. Gently tapping the plate on the work area surface after each addition to remove any air bubbles and to distribute the solution evenly within the wells.When all of the cells have been added, place the plate in a 37 degree Celsius incubator for at least two hours, adding 100 microliters of culture medium to each well after the first two hours if the cells are to be cultured overnight. To prepare the first fibrin gel layer, bring the freeze dried fibrinogen to room temperature before opening the vial to avoid hydrate crystal formation. Then transfer the fibrinogen to a glass beaker and add 37 degrees Celsius HBSS drop wise to the powder to solubilize the fibrinogen fragments.Next, use a spatula to break down the larger protein pieces, agitating the beaker from time to time as appropriate to facilitate mixing. Pipette the suspension several times to dissolve the remaining protein, and filter sterilize the solution through a 22 micron filter. Then immediately overlay the surface of each well of a 24 well plate with 200 microliters of the fibrinogen, taking care to avoid air bubbles.Once all of the wells have been thoroughly coated, tilt the plate at a 45 angle, then drop 1.5 microliters of thrombin solution into the center of one well and gently swirl the plate horizontally for one to two seconds. After treating five more wells with thrombin in the same manner, place the plate in a stable horizontal position under a laminar flow hood for five to 10 minutes, until the solutions gel. For immediate placement of the collagen plug, carefully tilt the plate to confirm that the fibrin gels are completely polymerized.Then place the 96 well plate of collagen gel plugs next to the 24 well plate of fibrin gels and add one drop of HBSS into each collagen plug well. Next, use a micro spoon to transfer a single collagen plug into the center of each of the first fibrin gel layers in the 24 well plate. When all of the plugs have been transferred, add 300 microliters of fibrinogen solution to each well, followed by the addition of 2.25 microliters of thrombin as just demonstrated.To coat the collagen plugs with a thin layer of growth factor reduced basement membrane before their placement, transfer each plug into a 1.5 milliliter centrifuge tube on ice containing 100 microliters of pure growth factor reduced basement membrane. After two minutes of soaking, transfer a single coated collagen plug into the center of each fibrin layer and incubate the plugs at 37 degrees Celsius for five minutes to solidify the growth factor reduced basement membrane. Then add the second fibrin layer as just demonstrated.When the gels are fully polymerized, fill each well with 400 microliters of the appropriate culture medium and supplements. Next, add an Antifibrinolytic agent to the wells. And incubate the 3D cultures under the appropriate conditions for the tumor cell line being tested.On the appropriate cell feeding days, tilt the plate at a 30 to 35 degree angle and incline a pipette against the wall of each well to aspirate the medium without disturbing the gels. Then add 400 microliters of fresh cell culture medium and Antifibrinolytic agent to each gel culture. This 3D cell culture assay allows a direct visualization of cancer cell migration from the collagen plug into the adjacent fibrin gel for the establishment of secondary tumors, allowing a comparison of the behavior or known metastatic cells to that of non or weakly metastatic cells.For example, in this experiment, numerous satellite tumors dispersed randomly throughout the fibrin gel containing the metastatic cell line B16 F10 while no satellite tumors were seen for the weakly metastatic B16 F0 cell line. By contrast, these murine mammary gland carcinoma cells which are poorly metastatic but very invasive locally form a migration front that extends radially into the fibrin gel. After 14 days of culture, the mammary gland carcinoma cells pull away from the migratory front to form stellar shaped structures closely resembling mammary gland structures.Chemotherapeutic agents can be tested on the embedded cancer cells as in this representative experiment where an increasing amount of DNA fragmentation were observed concomitant with the increased incidents of chemotherapeutic agent induced cancer cell apoptosis. When mastered, this technique can be completed in approximately six hours or spread across two days. Depending on the initial collagen plug incubation period.While I'm attempting this procedure, it's important to prevent the formation of gaps at the interface between the central and the peripheral gels as they can reduce the ability of the cancer cells to invade the fibrin gel. Following this procedure, metallographic or Proteomic analysis can be performed in the satellite colonies, the collagen plugs, or the cancer cells to identify the differential expression of genes and proteins of interest. After its development and this technique paved the way to researchers in the field of cancer biology to explore the migration apoptosis metastatic suppressive gene expression can end angiogenesis to a variety of cancer cell lines.After watching this video, you should have a good understanding of how to embed cancer cells in a collagen gel and sandwich them within a fibrin gel to monitor the invasiveness and formation of satellite tumors.

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Research

JoVE Journal

Medicine

Human Neuroendocrine Tumor Cell Lines as a Three-Dimensional Model for the Study of Human Neuroendocrine Tumor Therapy

Neuroendocrine tumors (NETs) are rare tumors, with an incidence of two per 100,&#x200A;000 individuals per year, and they account for 0.5% of all human malignancies.1 Other than surgery for the minority of patients who present with localized disease, there is little or no survival benefit of systemic therapy. Therefore, there is a great need to better understand the biology of NETs, and in particular define new therapeutic targets for patients with nonresectable or metastatic neuroendocrine tumors. 3D cell culture is becoming a popular method for drug screening due to its relevance in modeling the in vivo tumor tissue organization and microenvironment.2,3 The 3D multicellular spheroids could provide valuable information in a more timely and less expensive manner than directly proceeding from 2D cell culture experiments to animal (murine) models.
To facilitate the discovery of new therapeutics for NET patients, we have developed an in vitro 3D multicellular spheroids model using the human NET cell lines. The NET cells are plated in a non-adhesive agarose-coated 24-well plate and incubated under physiological conditions (5% CO2, 37 &deg;C) with a very slow agitation for 16-24 hr after plating. The cells form multicellular spheroids starting on the 3rd or 4th day. The spheroids become more spherical by the 6th day, at which point the drug treatments are initiated. The efficacy of the drug treatments on the NET spheroids is monitored based on the morphology, shape and size of the spheroids with a phase-contrast light microscope. The size of the spheroids is estimated automatically using a custom-developed MATLAB program based on an active contour algorithm. Further, we demonstrate a simple method to process the HistoGel embedding on these 3D spheroids, allowing the use of standard histological and immunohistochemical techniques. 
This is the first report on generating 3D spheroids using NET cell lines to examine the effect of therapeutic drugs. We have also performed histology on these 3D spheroids, and displayed an example of a single drug's effect on growth and proliferation of the NET spheroids. Our results support that the NET spheroids are valuable for further studies of NET biology and drug development.

We present a simple agarose overlay platform to grow 3D multicellular spheroids using neuroendocrine cancer cell lines. This method provides a very convenient way to examine the effect of therapeutic drugs on the neuroendocrine tumor cells. It could also help us establish human neuroendocrine tumor spheroids for cancer therapy.

Neuroendocrine tumors (NETs) are rare tumors, with an incidence of two per 100,&#x200A;000 individuals per year, and they account for 0.5% of all human ...

Patient Derived Cell Culture and Isolation of CD133+ Putative Cancer Stem Cells from Melanoma

Despite improved treatments options for melanoma available today, patients with advanced malignant melanoma still have a poor prognosis for progression-free and overall survival. Therefore, translational research needs to provide further molecular evidence to improve targeted therapies for malignant melanomas. In the past, oncogenic mechanisms related to melanoma were extensively studied in established cell lines. On the way to more personalized treatment regimens based on individual genetic profiles, we propose to use patient-derived cell lines instead of generic cell lines. Together with high quality clinical data, especially on patient follow-up, these cells will be instrumental to better understand the molecular mechanisms behind melanoma progression.
Here, we report the establishment of primary melanoma cultures from dissected fresh tumor tissue. This procedure includes mincing and dissociation of the tissue into single cells, removal of contaminations with erythrocytes and fibroblasts as well as primary culture and reliable verification of the cells' melanoma origin.
Recent reports revealed that melanomas, like the majority of tumors, harbor a small subpopulation of cancer stem cells (CSCs), which seem to exclusively fuel tumor initiation and progression towards the metastatic state. One of the key markers for CSC identification and isolation in melanoma is CD133. To isolate CD133+ CSCs from primary melanoma cultures, we have modified and optimized the Magnetic-Activated Cell Sorting (MACS) procedure from Miltenyi resulting in high sorting purity and viability of CD133+ CSCs and CD133- bulk, which can be cultivated and functionally analyzed thereafter.

Patient Derived Cell Culture and Isolation of CD133+ Putative Cancer Stem Cells from Melanoma

This article describes the preparation of freshly obtained melanoma tissue into primary cell cultures, and how to remove contaminations of erythrocytes and fibroblasts from the tumor cells. Finally, we describe how CD133+ putative melanoma stem cells are sorted from the CD133- bulk using Magnetic Activated Cell Sorting (MACS).

Despite improved treatments options for melanoma available today, patients with advanced malignant melanoma still have a poor prognosis for ...

The Use of Reverse Phase Protein Arrays (RPPA) to Explore Protein Expression Variation within Individual Renal Cell Cancers

Currently there is no curative treatment for metastatic clear cell renal cell cancer, the commonest variant of the disease. A key factor in this treatment resistance is thought to be the molecular complexity of the disease 1. Targeted therapy such as the tyrosine kinase inhibitor (TKI)-sunitinib have been utilized, but only 40% of patients will respond, with the overwhelming majority of these patients relapsing within 1 year 2. As such the question of intrinsic and acquired resistance in renal cell cancer patients is highly relevant 3.
In order to study resistance to TKIs, with the ultimate goal of developing effective, personalized treatments, sequential tissue after a specific period of targeted therapy is required, an approach which had proved successful in chronic myeloid leukaemia 4. However the application of such a strategy in renal cell carcinoma is complicated by the high level of both inter- and intratumoral heterogeneity, which is a feature of renal cell carcinoma5,6 as well as other solid tumors 7. Intertumoral heterogeneity due to transcriptomic and genetic differences is well established even in patients with similar presentation, stage and grade of tumor. In addition it is clear that there is great morphological (intratumoral) heterogeneity in RCC, which is likely to represent even greater molecular heterogeneity. Detailed mapping and categorization of RCC tumors by combined morphological analysis and Fuhrman grading allows the selection of representative areas for proteomic analysis.
Protein based analysis of RCC8 is attractive due to its widespread availability in pathology laboratories; however, its application can be problematic due to the limited availability of specific antibodies 9. Due to the dot blot nature of the Reverse Phase Protein Arrays (RPPA), antibody specificity must be pre-validated; as such strict quality control of antibodies used is of paramount importance. Despite this limitation the dot blot format does allow assay miniaturization, allowing for the printing of hundreds of samples onto a single nitrocellulose slide. Printed slides can then be analyzed in a similar fashion to Western analysis with the use of target specific primary antibodies and fluorescently labelled secondary antibodies, allowing for multiplexing. Differential protein expression across all the samples on a slide can then be analyzed simultaneously by comparing the relative level of fluorescence in a more cost-effective and high-throughput manner.

The Use of Reverse Phase Protein Arrays RPPA to Explore Protein Expression Variation within Individual Renal Cell Cancers

RPPA enables the protein expression of hundreds of samples, printed on nitrocellulose slides to be interrogated simultaneously, using fluorescently labelled antibodies. This technique has been applied to study the effect of drug treatment heterogeneity within clear cell renal carcinoma.

Currently there is no curative treatment for metastatic clear cell renal cell cancer, the commonest variant of the disease. A key factor in this treatment ...

A Three-dimensional Tissue Culture Model to Study Primary Human Bone Marrow and its Malignancies

Tissue culture has been an invaluable tool to study many aspects of cell function, from normal development to disease. Conventional cell culture methods rely on the ability of cells either to attach to a solid substratum of a tissue culture dish or to grow in suspension in liquid medium. Multiple immortal cell lines have been created and grown using such approaches, however, these methods frequently fail when primary cells need to be grown ex vivo. Such failure has been attributed to the absence of the appropriate extracellular matrix components of the tissue microenvironment from the standard systems where tissue culture plastic is used as a surface for cell growth. Extracellular matrix is an integral component of the tissue microenvironment and its presence is crucial for the maintenance of physiological functions such as cell polarization, survival, and proliferation. Here we present a 3-dimensional tissue culture method where primary bone marrow cells are grown in extracellular matrix formulated to recapitulate the microenvironment of the human bone (rBM system). Embedded in the extracellular matrix, cells are supplied with nutrients through the medium supplemented with human plasma, thus providing a comprehensive system where cell survival and proliferation can be sustained for up to 30 days while maintaining the cellular composition of the primary tissue. Using the rBM system we have successfully grown primary bone marrow cells from normal donors and patients with amyloidosis, and various hematological malignancies. The rBM system allows for direct, in-matrix real time visualization of the cell behavior and evaluation of preclinical efficacy of novel therapeutics. Moreover, cells can be isolated from the rBM and subsequently used for in vivo transplantation, cell sorting, flow cytometry, and nucleic acid and protein analysis. Taken together, the rBM method provides a reliable system for the growth of primary bone marrow cells under physiological conditions.

In standard culture methods cells are taken out of their physiological environment and grown on the plastic surface of a dish. To study the behavior of primary human bone marrow cells we created a 3-D culture system where cells are grown under conditions recapitulating the native microenvironment of the tissue.

Tissue culture has been an invaluable tool to study many aspects of cell function, from normal development to disease. Conventional cell culture methods ...

A Mouse Tumor Model of Surgical Stress to Explore the Mechanisms of Postoperative Immunosuppression and Evaluate Novel Perioperative Immunotherapies

Surgical resection is an essential treatment for most cancer patients, but surgery induces dysfunction in the immune system and this has been linked to the development of metastatic disease in animal models and in cancer patients. Preclinical work from our group and others has demonstrated a profound suppression of innate immune function, specifically NK cells in the postoperative period and this plays a major role in the enhanced development of metastases following surgery. Relatively few animal studies and clinical trials have focused on characterizing and reversing the detrimental effects of cancer surgery. Using a rigorous animal model of spontaneously metastasizing tumors and surgical stress, the enhancement of cancer surgery on the development of lung metastases was demonstrated. In this model, 4T1 breast cancer cells are implanted in the mouse mammary fat pad. At day 14 post tumor implantation, a complete resection of the primary mammary tumor is performed in all animals. A subset of animals receives additional surgical stress in the form of an abdominal nephrectomy. At day 28, lung tumor nodules are quantified. When immunotherapy was given immediately preoperatively, a profound activation of immune cells which prevented the development of metastases following surgery was detected. While the 4T1 breast tumor surgery model allows for the simulation of the effects of abdominal surgical stress on tumor metastases, its applicability to other tumor types needs to be tested. The current challenge is to identify safe and promising immunotherapies in preclinical mouse models and to translate them into viable perioperative therapies to be given to cancer surgery patients to prevent the recurrence of metastatic disease.

A mouse tumor model of surgical stress is used to explore how postoperative immune suppression promotes metastatic disease and to evaluate immunostimulatory perioperative therapies.

Surgical resection is an essential treatment for most cancer patients, but surgery induces dysfunction in the immune system and this has been linked to ...

Three Dimensional Cultures: A Tool To Study Normal Acinar Architecture vs. Malignant Transformation Of Breast Cells

Invasive breast carcinomas are a group of malignant epithelial tumors characterized by the invasion of adjacent tissues and propensity to metastasize. The interplay of signals between cancer cells and their microenvironment exerts a powerful influence on breast cancer growth and biological behavior1. However, most of these signals from the extracellular matrix are lost or their relevance is understudied when cells are grown in two dimensional culture (2D) as a monolayer. In recent years, three dimensional (3D) culture on a reconstituted basement membrane has emerged as a method of choice to recapitulate the tissue architecture of benign and malignant breast cells. Cells grown in 3D retain the important cues from the extracellular matrix and provide a physiologically relevant ex&#160;vivo system2,3. Of note, there is growing evidence suggesting that cells behave differently when grown in 3D as compared to 2D4. 3D culture can be effectively used as a means to differentiate the malignant phenotype from the benign breast phenotype and for underpinning the cellular and molecular signaling involved3. One of the distinguishing characteristics of benign epithelial cells is that they are polarized so that the apical cytoplasm is towards the lumen and the basal cytoplasm rests on the basement membrane. This apico-basal polarity is lost in invasive breast carcinomas, which are characterized by cellular disorganization and formation of anastomosing and branching tubules that haphazardly infiltrates the surrounding stroma. These histopathological differences between benign gland and invasive carcinoma can be reproduced in 3D6,7. Using the appropriate read-outs like the quantitation of single round acinar structures, or differential expression of validated molecular markers for cell proliferation, polarity and apoptosis in combination with other molecular and cell biology techniques, 3D culture can provide an important tool to better understand the cellular changes during malignant transformation and for delineating the responsible signaling.

Three dimensional culture of mammary epithelial cells on a reconstituted basement membrane is a useful method to recapitulate the in vivo architecture of the benign breast, and to differentiate the malignant phenotype from the benign breast phenotype. Importantly, this system can be applied to study invasive carcinomas in other tissues.

Invasive breast carcinomas are a group of malignant epithelial tumors characterized by the invasion of adjacent tissues and propensity to metastasize. The ...

Quantification of Breast Cancer Cell Invasiveness Using a Three-dimensional (3D) Model

It is now well known that the cellular and tissue microenvironment are critical regulators influencing tumor initiation and progression. Moreover, the extracellular matrix (ECM) has been demonstrated to be a critical regulator of cell behavior in culture and homeostasis in vivo. The current approach of culturing cells on two-dimensional (2D), plastic surfaces results in the disturbance and loss of complex interactions between cells and their microenvironment. Through the use of three-dimensional (3D) culture assays, the conditions for cell-microenvironment interaction are established resembling the in vivo microenvironment. This article provides a detailed methodology to grow breast cancer cells in a 3D basement membrane protein matrix, exemplifying the potential of 3D culture in the assessment of cell invasion into the surrounding environment. In addition, we discuss how these 3D assays have the potential to examine the loss of signaling molecules that regulate epithelial morphology by immunostaining procedures. These studies aid to identify important mechanistic details into the processes regulating invasion, required for the spread of breast cancer.

Quantification of Breast Cancer Cell Invasiveness Using a Three-dimensional 3D Model

This article provides detailed methodologies for the use of three-dimensional (3D) assays to quantify breast cancer cell invasion. Specifically, we discuss the procedures required to set up such assays, quantification, and data analysis, as well as methods to examine the loss of membrane integrity that occurs when cells invade.

It is now well known that the cellular and tissue microenvironment are critical regulators influencing tumor initiation and progression. Moreover, the ...

Three-dimensional Co-culture Model for Tumor-stromal Interaction

Cancer progression (initiation, growth, invasion and metastasis) occurs through interactions between malignant cells and the surrounding tumor stromal cells. The tumor microenvironment is comprised of a variety of cell types, such as fibroblasts, immune cells, vascular endothelial cells, pericytes and bone-marrow-derived cells, embedded in the extracellular matrix (ECM). Cancer-associated fibroblasts (CAFs) have a pro-tumorigenic role through the secretion of soluble factors, angiogenesis and ECM remodeling. The experimental models for cancer cell survival, proliferation, migration, and invasion have mostly relied on two-dimensional monocellular and monolayer tissue cultures or Boyden chamber assays. However, these experiments do not precisely reflect the physiological or pathological conditions in a diseased organ. To gain a better understanding of tumor stromal or tumor matrix interactions, multicellular and three-dimensional cultures provide more powerful tools for investigating intercellular communication and ECM-dependent modulation of cancer cell behavior. As a platform for this type of study, we present an experimental model in which cancer cells are cultured on collagen gels embedded with primary cultures of CAFs.

Here we present a protocol to co-culture in three-dimensions, which is useful for investigating multicellular interactions and extracellular matrix-dependent modulation of cancer cell behavior. In this experimental model, cancer cells are cultured on collagen gels embedded with human cancer-associated fibroblasts.

Cancer progression (initiation, growth, invasion and metastasis) occurs through interactions between malignant cells and the surrounding tumor stromal ...

Mammosphere Formation Assay from Human Breast Cancer Tissues and Cell Lines

Similar to healthy tissues, many blood and solid malignancies are now thought to be organised hierarchically, with a subset of stem-like cancer cells that self-renew while giving rise to more differentiated progeny. Understanding and targeting these cancer stem cells in breast cancer, which may possess enhanced chemo- and radio-resistance compared to the non-stem tumor bulk, has become an important research area. Markers including CD44, CD24, and ALDH activity can be assessed using fluorescence activated cell sorting (FACS) to prospectively isolate cells that display enhanced tumorigenicity when implanted into immunocompromised mice: the mammosphere assay has also become widely used for its ability to retrospectively identify sphere-forming cells that develop from single stem cell-like clones. Here we outline approaches for the appropriate culturing of mammospheres from cell lines or primary patient samples, their passaging, and calculations to estimate sphere forming efficiency (SFE). First we discuss key considerations and pitfalls in the appropriate planning and interpretation of mammosphere experiments.

Floating mammosphere assays can investigate the subset of stem-like breast cancer cells that survive in suspension conditions and show enhanced tumorigenesis when implanted into mice. This protocol provides a convenient in vitro measure of sphere-forming ability, a proxy for in vivo tumorigenesis, while facilitating analysis of the stem-associated transcriptional landscape.

Similar to healthy tissues, many blood and solid malignancies are now thought to be organised hierarchically, with a subset of stem-like cancer cells that ...

Three-Dimensional (3D) Tumor Spheroid Invasion Assay

Invasion of surrounding normal tissues is generally considered to be a key hallmark of malignant (as opposed to benign) tumors. For some cancers in particular (e.g., brain tumors such as glioblastoma multiforme and squamous cell carcinoma of the head and neck &#8211; SCCHN) it is a cause of severe morbidity and can be life-threatening even in the absence of distant metastases. In addition, cancers which have relapsed following treatment unfortunately often present with a more aggressive phenotype. Therefore, there is an opportunity to target the process of invasion to provide novel therapies that could be complementary to standard anti-proliferative agents. Until now, this strategy has been hampered by the lack of robust, reproducible assays suitable for a detailed analysis of invasion and for drug screening. Here we provide a simple micro-plate method (based on uniform, self-assembling 3D tumor spheroids) which has great potential for such studies. We exemplify the assay platform using a human glioblastoma cell line and also an SCCHN model where the development of resistance against targeted epidermal growth factor receptor (EGFR) inhibitors is associated with enhanced matrix-invasive potential. We also provide two alternative methods of semi-automated quantification: one using an imaging cytometer and a second which simply requires standard microscopy and image capture with digital image analysis.

Three-Dimensional 3D Tumor Spheroid Invasion Assay

Invasion of surrounding normal tissues is a defining characteristic of malignant tumors. We provide here a simple, semi-automated micro-plate assay of invasion into a natural 3D biomatrix that has been exemplified with a number of models of advanced human cancers.

Invasion of surrounding normal tissues is generally considered to be a key hallmark of malignant (as opposed to benign) tumors. For some cancers in ...