Name: using the chicken chorioallantoic membrane in vivo model to study gynecological and urological cancers
Uploaded: 2020-01-28T14:00:00
Description: Watch this Scientific Journal Video about Using the Chicken Chorioallantoic Membrane In Vivo Model to Study Gynecological and Urological Cancers at JoVE.com

The authors wish to thank Dr. Fuyuhiko Tamanoi and Binh Vu for the initial training on this method. Discussions with Dr. Eva Koziolek have been instrumental in optimizing this approach and have been very much appreciated. This work would not have been possible without funding from the following sources: the Tobacco-Related Disease Research Program Postdoctoral Fellowship (27FT-0023, to ACS), the Department of Defense (DoD) Ovarian Cancer Research Program (W81XWH-17-1-0160), NCI/NIH (1R21CA216770), Tobacco-Related Disease Research Program High Impact Pilot Award (27IR-0016), and UCLA institutional support, including a JCCC Seed Grant (NCI/NIH P30CA016042) and a 3R Grant from Office of the Vice Chancellor for Research to LW.

All of the experiments presented herein were reviewed and approved by the appropriate ethical committees at the University of California, Los Angeles (UCLA). The use of deidentified, primary human tumors has been approved by the UCLA Institutional Review Board (Protocol numbers 17-000037, 17-001169, and 11-001363). At UCLA, Animal Research Committee review is not required for experiments using chicken embryos; protocol approval is only required when the eggs will be hatched. However, best practices, such as the AVMA Guid...

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	<li>Kersten, K., de Visser, K. E., van Miltenburg, M. H., Jonkers, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetically+engineered+mouse+models+in+oncology+research+and+cancer+medicine.">Genetically engineered mouse models in oncology research and cancer medicine.</a> EMBO Molecular Medicine. 9 (2), 137-153 (2017).</li><li>Jackson, S. J., Thomas, 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=Human+tissue+models+in+cancer+research:+looking+beyond+the+mouse.">Human tissue models in cancer research: looking beyond the mouse.</a> Disease Models &amp; Mechanisms. 10 (8), 939-942 (2017).</li><li>Cheon, D. J., Orsulic, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+Models+of+Cancer.">Mouse Models of Cancer.</a> Annual Review of Pathology: Mechanisms of Disease. 6 (1), 95-119 (2011).</li><li>. SEER Cancer Statistics Review, 1975-2016 Available from: <a target="_blank" href="https://seer.cancer.gov/csr/1975_2016/">https://seer.cancer.gov/csr/1975_2016/</a> (2018)</li><li>Ribatti, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chicken+chorioallantoic+membrane+angiogenesis+model.">Chicken chorioallantoic membrane angiogenesis model.</a> Methods Molecular Biology. 843, 47-57 (2012).</li><li>Nowak-Sliwinska, P., Segura, T., Iruela-Arispe, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+chicken+chorioallantoic+membrane+model+in+biology,+medicine+and+bioengineering.">The chicken chorioallantoic membrane model in biology, medicine and bioengineering.</a> Angiogenesis. 17 (4), 779-804 (2014).</li><li>Lokman, N. A., Elder, A. S., Ricciardelli, C., Oehler, M. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chick+chorioallantoic+membrane+(CAM)+assay+as+an+in+vivo+model+to+study+the+effect+of+newly+identified+molecules+on+ovarian+cancer+invasion+and+metastasis.">Chick chorioallantoic membrane (CAM) assay as an in vivo model to study the effect of newly identified molecules on ovarian cancer invasion and metastasis.</a> International Journal of Molecular Science. 13 (8), 9959-9970 (2012).</li><li>Xiao, X., 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=Chick+Chorioallantoic+Membrane+Assay:+A+3D+Animal+Model+for+Study+of+Human+Nasopharyngeal+Carcinoma.">Chick Chorioallantoic Membrane Assay: A 3D Animal Model for Study of Human Nasopharyngeal Carcinoma.</a> PLoS ONE. 10 (6), e0130935 (2015).</li><li>Deryugina, E. I., Quigley, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chick+embryo+chorioallantoic+membrane+model+systems+to+study+and+visualize+human+tumor+cell+metastasis.">Chick embryo chorioallantoic membrane model systems to study and visualize human tumor cell metastasis.</a> Histochemistry and Cell Biology. 130 (6), 1119-1130 (2008).</li><li>Shoin, K., 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=Chick+Embryo+Assay+as+Chemosensitivity+Test+for+Malignant+Glioma.">Chick Embryo Assay as Chemosensitivity Test for Malignant Glioma.</a> Japanese Journal of Cancer Research. 82 (10), 1165-1170 (1991).</li><li>Hagedorn, 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=Accessing+key+steps+of+human+tumor+progression+in+vivo+by+using+an+avian+embryo+model.">Accessing key steps of human tumor progression in vivo by using an avian embryo model.</a> Proceedings of the National Academy of Science U S A. 102 (5), 1643-1648 (2005).</li><li>Kavaliauskait&#279;, D., 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=The+Effect+of+Sodium+Valproate+on+the+Glioblastoma+U87+Cell+Line+Tumor+Development+on+the+Chicken+Embryo+Chorioallantoic+Membrane+and+on+EZH2+and+p53+Expression.">The Effect of Sodium Valproate on the Glioblastoma U87 Cell Line Tumor Development on the Chicken Embryo Chorioallantoic Membrane and on EZH2 and p53 Expression.</a> BioMed Research International. 2017, 12 (2017).</li><li>Liu, 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=The+Histone+Methyltransferase+EZH2+Mediates+Tumor+Progression+on+the+Chick+Chorioallantoic+Membrane+Assay,+a+Novel+Model+of+Head+and+Neck+Squamous+Cell+Carcinoma.">The Histone Methyltransferase EZH2 Mediates Tumor Progression on the Chick Chorioallantoic Membrane Assay, a Novel Model of Head and Neck Squamous Cell Carcinoma.</a> Translational Oncology. 6 (3), 273-281 (2013).</li><li>Rudy, S. F., 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=In+vivo+Wnt+pathway+inhibition+of+human+squamous+cell+carcinoma+growth+and+metastasis+in+the+chick+chorioallantoic+model.">In vivo Wnt pathway inhibition of human squamous cell carcinoma growth and metastasis in the chick chorioallantoic model.</a> Journal of Otolaryngology - Head &amp; Neck Surgery. 45 (1), 26 (2016).</li><li>Canale, 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=Interleukin-27+inhibits+pediatric+B-acute+lymphoblastic+leukemia+cell+spreading+in+a+preclinical+model.">Interleukin-27 inhibits pediatric B-acute lymphoblastic leukemia cell spreading in a preclinical model.</a> Leukemia. 25, 1815 (2011).</li><li>Loos, C., 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=Amino-functionalized+nanoparticles+as+inhibitors+of+mTOR+and+inducers+of+cell+cycle+arrest+in+leukemia+cells.">Amino-functionalized nanoparticles as inhibitors of mTOR and inducers of cell cycle arrest in leukemia cells.</a> Biomaterials. 35 (6), 1944-1953 (2014).</li><li>Rovithi, 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=Development+of+bioluminescent+chick+chorioallantoic+membrane+(CAM)+models+for+primary+pancreatic+cancer+cells:+a+platform+for+drug+testing.">Development of bioluminescent chick chorioallantoic membrane (CAM) models for primary pancreatic cancer cells: a platform for drug testing.</a> Scientific Reports. 7, 44686 (2017).</li><li>Majern&#237;k, 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=Novel+Insights+into+the+Effect+of+Hyperforin+and+Photodynamic+Therapy+with+Hypericin+on+Chosen+Angiogenic+Factors+in+Colorectal+Micro-Tumors+Created+on+Chorioallantoic+Membrane.">Novel Insights into the Effect of Hyperforin and Photodynamic Therapy with Hypericin on Chosen Angiogenic Factors in Colorectal Micro-Tumors Created on Chorioallantoic Membrane.</a> International Journal of Molecular Science. 20 (12), 3004 (2019).</li><li>Swadi, 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=Optimising+the+chick+chorioallantoic+membrane+xenograft+model+of+neuroblastoma+for+drug+delivery.">Optimising the chick chorioallantoic membrane xenograft model of neuroblastoma for drug delivery.</a> BMC Cancer. 18 (1), 28 (2018).</li><li>Klingenberg, M., Becker, J., Eberth, S., Kube, D., Wilting, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+chick+chorioallantoic+membrane+as+an+in+vivo+xenograft+model+for+Burkitt+lymphoma.">The chick chorioallantoic membrane as an in vivo xenograft model for Burkitt lymphoma.</a> BMC Cancer. 14 (1), 339 (2014).</li><li>Avram, 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=Standardization+of+A375+human+melanoma+models+on+chicken+embryo+chorioallantoic+membrane+and+Balb/c+nude+mice.">Standardization of A375 human melanoma models on chicken embryo chorioallantoic membrane and Balb/c nude mice.</a> Oncology Reports. 38 (1), 89-99 (2017).</li><li>Zabielska-Koczywas, K., 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+chick+embryo+chorioallantoic+membrane+model+as+an+in+vivo+model+to+study+morphological+and+histopathological+features+of+feline+fibrosarcomas.">3D chick embryo chorioallantoic membrane model as an in vivo model to study morphological and histopathological features of feline fibrosarcomas.</a> BMC Veterinary Research. 13 (1), 201 (2017).</li><li>Skowron, M. 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=Applying+the+chicken+embryo+chorioallantoic+membrane+assay+to+study+treatment+approaches+in+urothelial+carcinoma.">Applying the chicken embryo chorioallantoic membrane assay to study treatment approaches in urothelial carcinoma.</a> Urologic Oncology: Seminars and Original Investigations. 35 (9), e511-e523 (2017).</li><li>Jefferies, B., 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=Non-invasive+imaging+of+engineered+human+tumors+in+the+living+chicken+embryo.">Non-invasive imaging of engineered human tumors in the living chicken embryo.</a> Scientific Reports. 7 (1), 4991 (2017).</li><li>Taizi, M., Deutsch, V. R., Leitner, A., Ohana, A., Goldstein, R. S. <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+and+rapid+in+vivo+system+for+testing+therapeutics+on+human+leukemias.">A novel and rapid in vivo system for testing therapeutics on human leukemias.</a> Experimental Hematology. 34 (12), 1698-1708 (2006).</li><li>Strojnik, T., Kavalar, R., Barone, T. A., Plunkett, R. 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+model+and+immunohistochemical+comparison+of+U87+human+glioblastoma+cell+xenografts+on+the+chicken+chorioallantoic+membrane+and+in+rat+brains.">Experimental model and immunohistochemical comparison of U87 human glioblastoma cell xenografts on the chicken chorioallantoic membrane and in rat brains.</a> Anticancer Research. 30 (12), 4851-4860 (2010).</li><li>Ribatti, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+chick+embryo+chorioallantoic+membrane+as+a+model+for+tumor+biology.">The chick embryo chorioallantoic membrane as a model for tumor biology.</a> Experimental Cell Research. 328 (2), 314-324 (2014).</li><li>Hu, 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=A+Non-integrating+Lentiviral+Approach+Overcomes+Cas9-Induced+Immune+Rejection+to+Establish+an+Immunocompetent+Metastatic+Renal+Cancer+Model.">A Non-integrating Lentiviral Approach Overcomes Cas9-Induced Immune Rejection to Establish an Immunocompetent Metastatic Renal Cancer Model.</a> Molecular Therapy - Methods &amp; Clinical Development. 9, 203-210 (2018).</li></ol>

Tumor expansion and engraftment using the CAM model permits more rapid and directly observable tumor growth than existing in vivo animal models. In addition, costs are significantly lower once the initial purchase of equipment is complete, especially when compared to the cost of immunocompromised mice. The initial, immunocompromised state of chicken embryos readily permits engraftment of human and murine tissue. Even with these strengths, the CAM model does have limitations. The short time that can be a benefit could als...

Mice have served as the classic model organism for the study of human diseases, including malignancy. As mammals, they share many similarities with humans. Their high degree of genetic similarity has permitted transgenic manipulation of the mouse genome to provide enormous insight into the genetic control of human diseases1. Extensive experience in the handling of and experimentation with mice has resulted in their being the model of choice for biomedical research. However, in addition to the ethical and scientific concerns regarding murine models, they can also be quite costly and time consuming2,3. The development of tumors can take weeks or even months. The housing at a typical institution alone can run in the hundreds to thousands of dollars while tumors are developing. Ovarian cancer is an example of this drawback because its growth in murine models can easily take months. Delays in research progress potentially impact ovarian cancer patients&#39; persistently low 5-year survival rate of only 47% (i.e., an increase in survival of only 10% over 30 years)4. Similarly, urological cancers (kidney, prostate, and bladder cancers) constitute 19% of all cancer cases in the United States and 11% of cancer-related deaths4. Thus, a novel in vivo approach to study gynecological and urological cancers could save a laboratory considerable time, labor, and money, even if this model is only applied to initial screening experiments. Additionally, the resulting acceleration of research findings could significantly impact the 177,000 individuals diagnosed with these cancers annually.
The chicken CAM model offers many advantages that address the aforementioned issues. A popular model to study angiogenesis5,6, tumor cell invasion7,8, and metastasis7,9, the chick embryo CAM model has already been used to study many forms of cancers, including glioma10,11,12, head and neck squamous cell carcinoma13,14, leukemia15,16, pancreatic cancer17, and colorectal cancer18. Additionally, CAM models have been generated for neuroblastoma19, Burkitt lymphoma20, melanoma21, and feline fibrosarcoma22. Prior studies have also presented engraftment of bladder cancer23 and prostate cancer cell lines24, but with limited protocol details. Not only are eggs much cheaper than mice, but they also produce highly reproducible results25,26. They show fast vasculature development, and tumor engraftment can occur in as quickly as a few days and be visualized longitudinally through the open window. With the 21 day time frame between egg fertilization and hatching, experiments can be completed within a few weeks. Furthermore, the low cost, limited housing needs, and small size readily permit large-scale experiments that would be prohibitive for mouse studies.
Therefore, we sought to optimize the CAM model for the engraftment of gynecological and urological cancers. Due to the immunocompromised status of the early chicken embryo27, both mouse and human cells can be readily implanted. As such, we have successfully engrafted ovarian, kidney, prostate, and bladder cancers. For each of these tumor types, the CAM readily accepts established murine and/or human tumor cell lines. Importantly, freshly harvested primary human tumor tissues can also engraft from either digested cells or pieces of solid tissue with high rates of success. Each of these cancer types and cell sources requires optimization, which we share here.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>-010 Teflon (PTFE) White 55 Duro Shore D O-Rings</td>
			<td>The O-Ring Store</td>
			<td>TEF010</td>
			<td>Nonstick ring for cell seeding. 1/4&#34;ID X 3/8&#34;OD X 1/16&#34;CS Polytetrafluoroethylene (PTFE).</td>
		</tr>
		<tr>
			<td>C4-2</td>
			<td>ATCC</td>
			<td>CRL-3314</td>
			<td>Human prostate cancer cell line.</td>
		</tr>
		<tr>
			<td>CWR22Rv1</td>
			<td></td>
			<td></td>
			<td>CWR cells were the kind gift of Dr. David Agus (Keck Medicine of University of Southern California)</td>
		</tr>
		<tr>
			<td>Cytokeratin 8/18 Antibody (C-51)</td>
			<td>Novus Biologicals</td>
			<td>NBP2-44929-0.02mg</td>
			<td>Used at a dilution of 1:100 for immunohistochemical analysis of human ovarian CAM tumors.</td>
		</tr>
		<tr>
			<td>D-Luciferin Firefly, potassium salt</td>
			<td>Goldbio</td>
			<td>LUCK-1G</td>
			<td></td>
		</tr>
		<tr>
			<td>Delicate Operating Scissors; Curved; Sharp-Sharp; 30mm Blade Length; 4-3/4 in. Overall Length</td>
			<td>Roboz Surgical</td>
			<td>RS6703</td>
			<td>This is provided as an example. Any similar curved scissors would work as well.</td>
		</tr>
		<tr>
			<td>Dremel 8050-N/18 Micro 8V Max Tool Kit</td>
			<td>Dremel</td>
			<td>8050-N/18</td>
			<td>This kit contains all necessary tools.</td>
		</tr>
		<tr>
			<td>Fertilized chicken eggs (Rhode Island Red - Brown, Lab Grade)</td>
			<td>AA Lab Eggs Inc.</td>
			<td>N/A</td>
			<td>A local egg supplier would need to be identified, as this supplier only delivers regionally.</td>
		</tr>
		<tr>
			<td>HT-1376</td>
			<td>ATCC</td>
			<td>CRL-1472</td>
			<td>Human bladder cancer cell line.</td>
		</tr>
		<tr>
			<td>Hovabator Genesis 1588 Deluxe Egg Incubator Combo Kit</td>
			<td>Incubator Warehouse</td>
			<td>HB1588D-NONE-1102-1588-1357</td>
			<td>Other egg incubators may be used, but their reliability would need to be verified. After implantation, a cell incubator with the CO2 disabled may also be used.</td>
		</tr>
		<tr>
			<td>ID8</td>
			<td></td>
			<td></td>
			<td>Not commercially available, please see PMID: 10753190.</td>
		</tr>
		<tr>
			<td>Incu-Bright Cool Light Egg Candler</td>
			<td>Incubator Warehouse</td>
			<td>1102</td>
			<td>Other candlers may be used; however, this is preferred among those that we have tested. This candler is included in the aforementioned incubator kit.</td>
		</tr>
		<tr>
			<td>Iris Forceps, 10cm, Curved, Serrated, 0.8mm tips</td>
			<td>World Precision Instrument</td>
			<td>15915</td>
			<td>This is provided as an example. Any similar curved forceps would work as well. Multiple brands have been used for this method.</td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>Clipper Distributing</td>
			<td>0010250</td>
			<td></td>
		</tr>
		<tr>
			<td>IVIS Lumina II In Vivo Imaging System</td>
			<td>Perkin Elmer</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Matrigel Membrane Matrix HC; LDEV-Free</td>
			<td>Corning</td>
			<td>354248</td>
			<td>Extracellular matrix solution</td>
		</tr>
		<tr>
			<td>MyC-CaP</td>
			<td>ATCC</td>
			<td>CRL-3255</td>
			<td>Murine prostate cancer cell line.</td>
		</tr>
		<tr>
			<td>Portable Pipet-Aid XP Pipette Controller</td>
			<td>Drummond Scientific</td>
			<td>4-000-101</td>
			<td>Any similar pipet controller would be appropriate.</td>
		</tr>
		<tr>
			<td>PrecisionGlide Hypodermic Needles</td>
			<td>BD</td>
			<td>305196</td>
			<td>This is provided as an example. Any 18G needle would work similarly.</td>
		</tr>
		<tr>
			<td>RENCA</td>
			<td>ATCC</td>
			<td>CRL-2947</td>
			<td></td>
		</tr>
		<tr>
			<td>Semken Forceps</td>
			<td>Fine Science Tools</td>
			<td>11008-13</td>
			<td>This is provided as an example. Any similar forceps or another style that suits researcher preference would be appropriate.</td>
		</tr>
		<tr>
			<td>SKOV3</td>
			<td>ATCC</td>
			<td>HTB-77</td>
			<td>Human ovarian cancer cell line.</td>
		</tr>
		<tr>
			<td>Specimen forceps</td>
			<td>Electron Microscopy Sciences</td>
			<td>72914</td>
			<td>This is provided as an example. The forceps used for pulling away the shell for bioluminescence imaging are approximately 12.8 cm long with 3 mm-wide tips.</td>
		</tr>
		<tr>
			<td>Sterile Cotton Balls</td>
			<td>Fisherbrand</td>
			<td>22-456-885</td>
			<td>This is provided as an example. Any sterile cotton balls would suffice.</td>
		</tr>
		<tr>
			<td>Stirring Rods with Rubber Policeman; 5mm diameter, 6 in. length</td>
			<td>United Scientific Supplies</td>
			<td>GRPL06</td>
			<td>This is provided as an example. Any similar glass stir rods would work as well.</td>
		</tr>
		<tr>
			<td>T24</td>
			<td>ATCC</td>
			<td>HTB-4</td>
			<td>Human bladder cancer cell line.</td>
		</tr>
		<tr>
			<td>Tegaderm Transparent Dressing Original Frame Style 2 3/8&#34; x 2 3/4&#34;</td>
			<td>Moore Medical</td>
			<td>21272</td>
			<td></td>
		</tr>
		<tr>
			<td>Tissue Culture Dishes, 10 cm diameter</td>
			<td>Corning</td>
			<td>353803</td>
			<td>This is provided as an example. Any similar, sterile 10-cm dish may be used. Tissue culture treatment is not necessary.</td>
		</tr>
		<tr>
			<td>Tygon Clear Laboratory Tubing - 1/4 x 3/8 x 1/16 wall (50 feet)</td>
			<td>Tygon</td>
			<td>AACUN017</td>
			<td>This is provided as an example. Any similarly sized tubing would work as well.</td>
		</tr>
	</tbody>
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using the chicken chorioallantoic membrane in vivo model to study gynecological and urological cancers

Mouse models are the benchmark tests for in vivo cancer studies. However, cost, time, and ethical considerations have led to calls for alternative in vivo cancer models. The chicken chorioallantoic membrane (CAM) model provides an inexpensive, rapid alternative that permits direct visualization of tumor development and is suitable for in vivo imaging. As such, we sought to develop an optimized protocol for engrafting gynecological and urological tumors into this model, which we present here. Approximately 7 days postfertilization, the air cell is moved to the vascularized side of the egg, where an opening is created in the shell. Tumors from murine and human cell lines and primary tissues can then be engrafted. These are typically seeded in a mixture of extracellular matrix and medium to avoid cellular dispersal and provide nutrient support until the cells recruit a vascular supply. Tumors may then grow for up to an additional 14 days prior to the eggs hatching. By implanting cells stably transduced with firefly luciferase, bioluminescence imaging can be used for the sensitive detection of tumor growth on the membrane and cancer cell spread throughout the embryo. This model can potentially be used to study tumorigenicity, invasion, metastasis, and therapeutic effectiveness. The chicken CAM model requires significantly less time and financial resources compared to traditional murine models. Because the eggs are immunocompromised and immune tolerant, tissues from any organism can potentially be implanted without costly transgenic animals (e.g., mice) required for implantation of human tissues. However, many of the advantages of this model could potentially also be limitations, including the short tumor generation time and immunocompromised/immune tolerant status. Additionally, although all tumor types presented here engraft in the chicken chorioallantoic membrane model, they do so with varying degrees of tumor growth.

Thus far, we have found this method of implantation to be successful for ovarian, kidney, prostate, and bladder cancers. Each was optimized to identify specific conditions for implantation, although there may be flexibility. Of the tested tumor types, ovarian cancer growth was much less pronounced and typically not visible without the assistance of bioluminescence imaging (Figure 1). However, a stiffening of the CAM could be felt with forceps in the area of i...

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Using the Chicken Chorioallantoic Membrane In Vivo Model to Study Gynecological and Urological Cancers

We present the chicken chorioallantoic membrane model as an alternative, transplantable, in vivo model for the engraftment of gynecological and urological cancer cell lines and patient-derived tumors.

Mouse models are the benchmark tests for in vivo cancer studies. However, cost, time, and ethical considerations have led to calls for alternative in vivo ...

The engraftment of tumors onto the chicken chorioallantoic membrane, or CAM, can be used for studies of tumorigenicity, treatment efficacy or cellular crosstalk. This method permits cost effective rapid tumor growth in an immunotolerant in vivo setting. Using the CAM model, novel therapeutic approaches can be rapidly tested using cell lines or even patient tumor specimens.The most crucial aspects of this protocol are ensuring proper CAM formation and not disrupting the CAM or vasculature while opening the eggs. On developmental day seven or eight when the CAM has fully developed, turn off the egg rotator and place approximately one to three eggs into the egg rack in the biosafety cabinet. With the lights turned off, place an egg candler against the egg shell to identify and mark the location of the air cell of one egg, then move the egg candler over the shell to find a large blood vessel network, rotating the egg as necessary.An ideal vasculature will branch near the middle of the egg. Use a marker to trace the vasculature to be used for implantation. After turning back on the light in the hood, use a cordless rotary tool fitted with a silicon carbide grinding stone to drill a small hole in the shell directly over the center of the air cell.When most of the shell has been removed but with white inner membrane intact, drill another small hole where the vascular window will be opened as just demonstrated. When the second hole is ready, use an 18 gauge needle to gently pierce the white inner membrane over the air cell and vasculature taking care that the white inner membrane, but not the CAM, is disrupted throughout the entirety of the drilled area. With the hood light off again, use the egg candler to verify that the air cell has been transferred from the end of the egg to the area over the vasculature.If necessary, place vacuum tubing inserted into a pipette controller around the hole over the original air cell and gently apply suction in short bursts to move the air cell. Mark the outline of the new location of the air cell approximately 0.5 centimeters inside the air CAM boundary and fix a piece of packing tape just big enough to cover the hole over the new air cell. After preparing the other two eggs as just demonstrated, return the eggs to the incubator and open any additional eggs for the experiment in groups of one to three as demonstrated.When all of the eggs have been opened, transfer one to three eggs with relocated air cells to the egg rack in a biosafety cabinet and use a cordless rotary tool fitted with a circular cutting wheel to cut a small line over the air cell boundary completely through the cell without disrupting the CAM or vasculature. Using curved scissors, cut around the remaining air cell to create a window in the shell and verify the viability of the embryo. Viable embryos will display an extensive vasculature, clear albumin, embryo movement, and/or a visible heartbeat.In nonviable embryos, the CAM may appear opaque with few, if any, vessels present and the embryos may be small or absent without movement or a heartbeat. Using Semkin forceps, pull small pieces of cotton from a sterile cotton ball and gently blot the CAM surface of the viable embryos to remove any shell dust and debris, then cover the shell opening with a one-quarter piece of six by seven centimeter transparent film dressing without touching the CAM and return the eggs to the incubator with the opened window facing up. Use a piece of egg rack, the edge of the egg rotator, or another suitable item to prop any eggs that keep rolling.To prepare cancer cell suspension for transplantation, harvest the cells from the cancer cell culture of interest and sediment the cells by centrifugation. Aspirate the supernatant and mechanically resuspend the cells in the residual medium. Place the cell suspension on ice and use a pipette to measure the volume of cells in medium.Then resuspend the cells at a concentration of one to two million cells in 20 to 100 microliters of medium supplemented with 2.7 to 4 milligrams per milliliter extracellular matrix and any growth factors or other additives of interest. For cancer cell implantation, using a non-stick ring, place up to six eggs to be implanted onto the egg rack and roll the edges of the transparent film dressing toward the open window to remove the film from the shells. Check whether the eggs are viable and healthy.Ideal eggs will have a large vessel with smaller branching vessels within the center of the opened area. Using curved iris forceps, place a sterile non-stick ring onto the CAM over the vessel ideally over a branch point. Use a sterile glass stir rod to gently abrade the CAM and pipette the cancer cell suspension into the center of the ring.When all of the cells have been delivered, seal the opening with a one-quarter piece of six by seven centimeter transparent film dressing and label the egg with an appropriate implant designation. Then place the eggs securely in the incubator with the opening of the shell facing upright. To implant cancer cells without the use of a non-stick ring, aspirate the cell suspension into an appropriately sized pipette tip and holding the top portion of the tip carefully eject the pipette tip and place the tip horizontally into a sterile 10 centimeter tissue culture dish.After the tips have been loaded, place the dish into a 37 degree Celsius incubator for 15 to 30 minutes, checking for polymerization after 15 minutes. A small amount of liquid will typically leak out as each tip is placed in the dish. Use this liquid to estimate the extent of the polymerization within the tip.When the matrix is ready, place one tip onto an appropriately sized pipette and depress the plunger to force the partially polymerized cell suspension onto the CAM ideally over the branched point of a large well-developed vessel. Using these methods, both human and murine ovarian cancer cell lines and primary tumor pieces resulted in the successful engraftment of tumors with morphologies consistent with those observed in other in vivo models. Of the tested tumor types, ovarian cancer growth was much less pronounced and typically not visible without the assistance of bioluminescence imaging.The effects of adding growth factors or hormones at the time of implantation can also be tested using these methods. For kidney cancer, the implantation of clear cell renal cell carcinoma cells from established cell lines or pieces from primary human renal tumors produces rapid, robust tumor formation. Further, multiple human and murine prostate cancer cell lines and human bladder cancer cell lines and primary tumor pieces had been used to establish tumors using this model.It is crucial to avoid disrupting the CAM and the vasculature and to make sure that the CAM does not adhere to the shell while opening the window. After successful engraftment, the CAM model can be used to assess the therapeutic efficacy of treatments of interest or interactions between different cell types within a tumor.

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Research

JoVE Journal

Cancer Research

Coculture Assays to Study Macrophage and Microglia Stimulation of Glioblastoma Invasion

Glioblastoma multiforme (grade IV glioma) is a very aggressive human cancer with a median survival of 1 year post diagnosis. Despite the increased understanding of the molecular events that give rise to glioblastomas, this cancer still remains highly refractory to conventional treatment. Surgical resection of high grade brain tumors is rarely complete due to the highly infiltrative nature of glioblastoma cells. Therapeutic approaches which attenuate glioblastoma cell invasion therefore is an attractive option. Our laboratory and others have shown that tumor associated macrophages and microglia (resident brain macrophages) strongly stimulate glioblastoma invasion. The protocol described in this paper is used to model glioblastoma-macrophage/microglia interaction using in vitro culture assays. This approach can greatly facilitate the development and/or discovery of drugs that disrupt the communication with the macrophages that enables this malignant behavior. We have established two robust coculture invasion assays where microglia/macrophages stimulate glioma cell invasion by 5 - 10 fold. Glioblastoma cells labelled with a fluorescent marker or constitutively expressing a fluorescent protein are plated without and with macrophages/microglia on matrix-coated polycarbonate chamber inserts or embedded in a three dimensional matrix. Cell invasion is assessed by using fluorescent microscopy to image and count only invasive cells on the underside of the filter. Using these assays, several pharmacological inhibitors (JNJ-28312141, PLX3397, Gefitinib, and Semapimod), have been identified which block macrophage/microglia stimulated glioblastoma invasion.

Understanding the malignant behavior of cancer requires creating accurate models of how tumor cells interact with components of the tumor microenvironment, such as macrophages. Here we describe two methods to study glioblastoma cell interaction with tumor associated macrophages and microglia where the effect on glioblastoma invasion is assessed.

Glioblastoma multiforme (grade IV glioma) is a very aggressive human cancer with a median survival of 1 year post diagnosis. Despite the increased ...

The Drosophila Imaginal Disc Tumor Model: Visualization and Quantification of Gene Expression and Tumor Invasiveness Using Genetic Mosaics

Drosophila melanogaster has emerged as a powerful experimental system for functional and mechanistic studies of tumor development and progression in the context of a whole organism. Sophisticated techniques to generate genetic mosaics facilitate induction of visually marked, genetically defined clones surrounded by normal tissue. The clones can be analyzed through diverse molecular, cellular and omics approaches. This study describes how to generate fluorescently labeled clonal tumors of varying malignancy in the eye/antennal imaginal discs (EAD) of Drosophila larvae using the Mosaic Analysis with a Repressible Cell Marker (MARCM) technique. It describes procedures how to recover the mosaic EAD and brain from the larvae and how to process them for simultaneous imaging of fluorescent transgenic reporters and antibody staining. To facilitate molecular characterization of the mosaic tissue, we describe a protocol for isolation of total RNA from the EAD. The dissection procedure is suitable to recover EAD and brains from any larval stage. The fixation and staining protocol for imaginal discs works with a number of transgenic reporters and antibodies that recognize Drosophila proteins. The protocol for RNA isolation can be applied to various larval organs, whole larvae, and adult flies. Total RNA can be used for profiling of gene expression changes using candidate or genome-wide approaches. Finally, we detail a method for quantifying invasiveness of the clonal tumors. Although this method has limited use, its underlying concept is broadly applicable to other quantitative studies where cognitive bias must be avoided.

The Drosophila Imaginal Disc Tumor Model: Visualization and Quantification of Gene Expression and Tumor Invasiveness Using Genetic Mosaics

This protocol demonstrates how to generate fluorescently marked, genetically defined clonal tumors in the Drosophila eye/antennal imaginal discs (EAD). It describes how to dissect the EAD and brain from the third instar larvae and how to process them to visualize and quantify gene expression changes and tumor invasiveness.

Drosophila melanogaster has emerged as a powerful experimental system for functional and mechanistic studies of tumor development and progression in the ...

Live Imaging to Study Microtubule Dynamic Instability in Taxane-resistant Breast Cancers

Taxanes such as docetaxel belong to a group of microtubule-targeting agents (MTAs) that are commonly relied upon to treat cancer. However, taxane resistance in cancerous cells drastically reduces the effectiveness of the drugs' long-term usage. Accumulated evidence suggests that the mechanisms underlying taxane resistance include both general mechanisms, such as the development of multidrug resistance due to the overexpression of drug-efflux proteins, and taxane-specific mechanisms, such as those that involve microtubule dynamics. 
Because taxanes target cell microtubules, measuring microtubule dynamic instability is an important step in determining the mechanisms of taxane resistance and provides insight into how to overcome this resistance. In the experiment, an in vivo method was used to measure microtubule dynamic instability. GFP-tagged &#945;-tubulin was expressed and incorporated into microtubules in MCF-7 cells, allowing for the recording of the microtubule dynamics by time lapse using a sensitive camera. The results showed that, as opposed to the non-resistant parental MCF-7CC cells, the microtubule dynamics of docetaxel-resistant MCF-7TXT cells are insensitive to docetaxel treatment, which causes the resistance to docetaxel-induced mitotic arrest and apoptosis. This paper will outline this in vivo method of measuring microtubule dynamic instability.

In this paper, we report a protocol describing an in vivo method to measure microtubule dynamic instability in docetaxel-resistant breast cancer cells (MCF-7TXT). In this method, a deconvolution microscopy imaging system is used to detect the expression of GFP-tubulin in target cells.

Taxanes such as docetaxel belong to a group of microtubule-targeting agents (MTAs) that are commonly relied upon to treat cancer. However, taxane ...

Detection of Mitochondria Membrane Potential to Study CLIC4 Knockdown-induced HN4 Cell Apoptosis In Vitro

Depletion of the mitochondrial membrane potential (MMP, &#916;&#936;m) is considered the earliest event in the apoptotic cascade. It even occurs ahead of nuclear apoptotic characteristics, including chromatin condensation and DNA breakage. Once the MMP collapses, cell apoptosis will initiate irreversibly. A series of lipophilic cationic dyes can pass through the cell membrane and aggregate inside the matrix of mitochondrion, and serve as fluorescence marker to evaluate MMP change. As one of the six members of the Cl- intracellular channel (CLIC) family, CLIC4 participates in the cell apoptotic process mainly through the mitochondrial pathway. Here we describe a detailed protocol to measure MMP via monitoring the fluorescence fluctuation of Rhodamine 123 (Rh123), through which we study apoptosis induced by CLIC4 knockdown. We discuss the advantages and limitations of the application of confocal laser scanning and normal fluorescence microscope in detail, and also compare it with other methods.

Detection of Mitochondria Membrane Potential to Study CLIC4 Knockdown-induced HN4 Cell Apoptosis In Vitro

Here we present a detailed protocol for the application of rhodamine 123 to identify the mitochondrial membrane potential (MMP) and study CLIC4 knockdown-induced HN4 cell apoptosis in vitro. Under common fluorescence microscope and confocal laser scanning fluorescence microscope, the real-time change of the MMP was recorded.

Depletion of the mitochondrial membrane potential (MMP, &#916;&#936;m) is considered the earliest event in the apoptotic cascade. It even occurs ahead of ...

In Vivo EPR Assessment of pH, pO2, Redox Status, and Concentrations of Phosphate and Glutathione in the Tumor Microenvironment

This protocol demonstrates the capability of low-field electron paramagnetic resonance (EPR)-based techniques in combination with functional paramagnetic probes to provide quantitative information on the chemical tumor microenvironment (TME), including pO2, pH, redox status, concentrations of interstitial inorganic phosphate (Pi), and intracellular glutathione (GSH). In particular, an application of a recently developed soluble multifunctional trityl probe provides unsurpassed opportunity for in vivo concurrent measurements of pH, pO2 and Pi in Extracellular space (HOPE probe). The measurements of three parameters using a single probe allow for their correlation analyses independent of probe distribution and time of the measurements.

In Vivo EPR Assessment of pH, pO2, Redox Status, and Concentrations of Phosphate and Glutathione in the Tumor Microenvironment

Low-field (L-band, 1.2 GHz) electron paramagnetic resonance using soluble nitroxyl and trityl probes is demonstrated for assessment of physiologically important parameters in the tumor microenvironment in mouse models of breast cancer.

This protocol demonstrates the capability of low-field electron paramagnetic resonance (EPR)-based techniques in combination with functional paramagnetic ...

Acellular and Cellular Lung Model to Study Tumor Metastasis

It is difficult to isolate tumor cells at different points of tumor progression. We created an ex vivo lung model that can show the interaction of tumor cells with a natural matrix and continual flow of nutrients, as well as a model that shows the interaction of tumor cells with normal cellular components and a natural matrix. The acellular ex vivo lung model is created by isolating a rat heart-lung block and removing all the cells using the decellularization process. The right main bronchus is tied off and tumor cells are placed in the trachea by a syringe. The cells move and populate the left lung. The lung is then placed in a bioreactor where the pulmonary artery receives a continual flow of media in a closed circuit. The tumor grown on the left lung is the primary tumor. The tumor cells that are isolated in the circulating media are circulating tumor cells and the tumor cells in the right lung are metastatic lesions. The cellular ex vivo lung model is created by skipping the decellularization process. Each model can be used to answer different research questions.

Here, we present a protocol for an ex vivo lung cancer model that mimics the steps of tumor progression and helps to isolate a primary tumor, circulating tumor cells, and metastatic lesions.

It is difficult to isolate tumor cells at different points of tumor progression. We created an ex vivo lung model that can show the interaction of tumor ...

Obtaining Cancer Stem Cell Spheres from Gynecological and Breast Cancer Tumors

Cancer stem cells (CSC) are a small population with self-renewal and plasticity which are responsible for tumorigenesis, resistance to treatment and recurrent disease. This population can be identified by surface markers, enzymatic activity and a functional profile. These approaches per se are limited, due to phenotypic heterogeneity and CSC plasticity. Here, we update the sphere-forming protocol to obtain CSC spheres from breast and gynecological cancers, assessing functional properties, CSC markers and protein expression. The spheres are obtained with single-cell seeding at low density in suspension culture, using a semi-solid methylcellulose medium to avoid migration and aggregates. This profitable protocol can be used in cancer cell lines but also in primary tumors. The tridimensional non-adherent suspension culture thought to mimic the tumor microenvironment, particularly the CSC-niche, is supplemented with epidermal growth factor and basic fibroblast growth factor to ensure CSC signaling. Aiming for robust identification of CSC, we propose a complementary approach, combining functional and phenotypic evaluation. Sphere-forming capacity, self-renewal and sphere projection area establish CSC functional properties. Additionally, characterization comprises flow cytometry evaluation of the markers, represented by CD44+/CD24- and CD133, and Western blot, considering ALDH. The presented protocol was also optimized for primary tumor samples, following a sample digestion procedure, useful for translational research.

The aim of this methodology is to identify cancer stem cells (CSC) in cancer cell lines and primary human tumor samples with the sphere-forming protocol, in a robust manner, using functional assays and phenotypic characterization with flow cytometry and Western blot.

Cancer stem cells (CSC) are a small population with self-renewal and plasticity which are responsible for tumorigenesis, resistance to treatment and ...

Comparing Metastatic Clear Cell Renal Cell Carcinoma Model Established in Mouse Kidney and on Chicken Chorioallantoic Membrane

Metastatic clear cell renal cell carcinoma (ccRCC) is the most common subtype of kidney cancer. Localized ccRCC has a favorable surgical outcome. However, one third of ccRCC patients will develop metastases to the lung, which is related to a very poor outcome for patients. Unfortunately, no therapy is available for this deadly stage, because the molecular mechanism of metastasis remains unknown. It has been known for 25 years that the loss of function of the von Hippel-Lindau (VHL) tumor suppressor gene is pathognomonic of ccRCC. However, no clinically relevant transgenic mouse model of ccRCC has been generated. The purpose of this protocol is to introduce and compare two newly established animal models for metastatic ccRCC. The first is renal implantation in the mouse model. In our laboratory, the CRISPR gene editing system was utilized to knock out the VHL gene in several RCC cell lines. Orthotopic implantation of heterogeneous ccRCC populations to the renal capsule created novel ccRCC models that develop robust lung metastases in immunocompetent mice. The second model is the chicken chorioallantoic membrane (CAM) system. In comparison to the mouse model, this model is more time, labor, and cost-efficient. This model also supported robust tumor formation and intravasation. Due to the short 10 day period of tumor growth in CAM, no overt metastasis was observed by immunohistochemistry (IHC) in the collected embryo tissues. However, when tumor growth was extended by two weeks in the hatched chicken, micrometastatic ccRCC lesions were observed by IHC in the lungs. These two novel preclinical models will be useful to further study the molecular mechanism behind metastasis, as well as to establish new, patient-derived xenografts (PDXs) toward the development of novel treatments for metastatic ccRCC.

Metastatic clear cell renal cell carcinoma is a disease without a comprehensive animal model for thorough preclinical investigation. This protocol illustrates two novel animal models for the disease: the orthotopically implanted mouse model and the chicken chorioallantoic membrane model, both of which demonstrate lung metastasis resembling clinical cases.

Metastatic clear cell renal cell carcinoma (ccRCC) is the most common subtype of kidney cancer. Localized ccRCC has a favorable surgical outcome. However, ...

Using Computer-based Image Analysis to Improve Quantification of Lung Metastasis in the 4T1 Breast Cancer Model

Breast cancer is a devastating malignancy, accounting for 40,000 female deaths and 30% of new female cancer diagnoses in the United States in 2019 alone. The leading cause of breast cancer related deaths is the metastatic burden. Therefore, preclinical models for breast cancer need to analyze metastatic burden to be clinically relevant. The 4T1 breast cancer model provides a spontaneously-metastasizing, quantifiable mouse model for stage IV human breast cancer. However, most 4T1 protocols quantify the metastatic burden by manually counting stained colonies on tissue culture plates. While this is sufficient for tissues with lower metastatic burden, human error in manual counting causes inconsistent and variable results when plates are confluent and difficult to count. This method offers a computer-based solution to human counting error. Here, we evaluate the protocol using the lung, a highly metastatic tissue in the 4T1 model. Images of methylene blue-stained plates are acquired and uploaded for analysis in Fiji-ImageJ. Fiji-ImageJ then determines the percentage of the selected area of the image that is blue, representing the percentage of the plate with metastatic burden. This computer-based approach offers more consistent and expeditious results than manual counting or histopathological evaluation for highly metastatic tissues. The consistency of Fiji-ImageJ results depends on the quality of the image. Slight variations in results between images can occur, thus it is recommended that multiple images are taken and results averaged. Despite its minimal limitations, this method is an improvement to quantifying metastatic burden in the lung by offering consistent and rapid results.

We describe a more consistent and expeditious method to quantify lung metastasis in the 4T1 breast cancer model by using Fiji-ImageJ.

Breast cancer is a devastating malignancy, accounting for 40,000 female deaths and 30% of new female cancer diagnoses in the United States in 2019 alone. ...

Discovery of Metastatic Regulators using a Rapid and Quantitative Intravital Chick Chorioallantoic Membrane Model

Recent advances in cancer research has illustrated the highly complex nature of cancer metastasis. Multiple genes or genes networks have been found to be involved in differentially regulating cancer metastatic cascade genes and gene products dependent on the cancer type, tissue, and individual patient characteristics. These represent potentially important targets for genetic therapeutics and personalized medicine approaches. The development of rapid screening platforms is essential for the identification of these genetic targets.
The chick chorioallantoic membrane (CAM) is a highly vascularized, collagen rich membrane located under the eggshell that allows for gas exchange in the developing embryo. Due to the location and vascularization of the CAM, we developed it as an intravital human cancer metastasis model that allows for robust human cancer cell xenografting and real-time imaging of cancer cell interactions with the collagen rich matrix and vasculature. 
Using this model, a quantitative screening platform was designed for the identification of novel drivers or suppressors of cancer metastasis. We transduced a pool of head and neck HEp3 cancer cells with a complete human genome shRNA gene library, then injected the cells, at low density, into the CAM vasculature. The cells proliferated and formed single-tumor cell colonies. Individual colonies that were unable to invade into the CAM tissue were visible as a compact colony phenotype and excised for identification of the transduced shRNA present in the cells. Images of individual colonies were evaluated for their invasiveness. Multiple rounds of selections were performed to decreases the rate of false positives. Individual, isolated cancer cell clones or newly engineered clones that express genes of interest were subjected to primary tumor formation assay or cancer cell vasculature co-option analysis. In summary we present a rapid screening platform that allows for anti-metastatic target identification and intravital analysis of a dynamic and complex cascade of events.

This is an effective method to screen for suppressors or drivers of cancer metastasis. Cells, transduced with an expression library, are injected into the chicken chorioallantoic membrane vasculature to form metastatic colonies. Colonies having decreased or increased invasiveness are excised, expanded, reinjected to confirm their phenotype, and finally, analyzed using high throughput sequencing.

Recent advances in cancer research has illustrated the highly complex nature of cancer metastasis. Multiple genes or genes networks have been found to be ...