A.S. was partially supported by grants from the National Institutes of Health (NIH) National Institute of Dental and Craniofacial Research (5R03DE021741-02) and the National Cancer Institute (1K08CA154963-01A1).&#160;
The Howard Hughes Medical Institute provided funding for M.L. through the HHMI Medical Research Fellows Program.

1. Egg Incubation
<ol>
	<li>Obtain 8 day old specific pathogen-free embryonated eggs.</li>
	<li>Place eggs in rotating egg tray, stamped ends facing upwards, and place the rotating tray inside an egg incubator. Incubate eggs for 48 hr&#160;at 36 &#176;C and 50% humidity.</li>
</ol>
2. Dropping the CAM and Opening the Eggs
<ol>
	<li>Gather eggs from incubator. Place eggs in egg rack, stamped side up, and bring to laminar flow hood.</li>
	<li>Turn off the room and hood lights.</li>
	<li>Hold the...

<ol>
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M., Burroughs, A., Bruix, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hepatocellular+carcinoma.">Hepatocellular carcinoma.</a> Lancet. 362 (9399), 1907-1917 (2003).</li><li>Folkman, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=What+is+the+evidence+that+tumors+are+angiogenesis+dependent.">What is the evidence that tumors are angiogenesis dependent.</a> J Natl Cancer Inst. 82, 4-6 (1990).</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> Proc Natl Acad Sci U S A. 102 (5), 1643-1648 (2005).</li><li>Dumartin, L., 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=Netrin-1+mediates+early+events+in+pancreatic+adenocarcinoma+progression,+acting+on+tumor+and+endothelial+cells.">Netrin-1 mediates early events in pancreatic adenocarcinoma progression, acting on tumor and endothelial cells.</a> Gastroenterology. 138 (4), 1595-1606 (2010).</li><li>Aguirre-Ghiso, J. A., Estrada, Y., Liu, D., Ossowski, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ERK(MAPK)+activity+as+a+determinant+of+tumor+growth+and+dormancy;+regulation+by+p38(SAPK).">ERK(MAPK) activity as a determinant of tumor growth and dormancy; regulation by p38(SAPK).</a> Cancer Res. 63 (7), 1684-1695 (2003).</li><li>Baroni, T. E., 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=Ribonomic+and+short+hairpin+RNA+gene+silencing+methods+to+explore+functional+gene+programs+associated+with+tumor+growth+arrest.">Ribonomic and short hairpin RNA gene silencing methods to explore functional gene programs associated with tumor growth arrest.</a> Methods Mol Biol. 383, 227-244 (2007).</li><li>Lopez-Rivera, E., 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=Inducible+nitric+oxide+synthase+drives+mTOR+pathway+activation+and+proliferation+of+human+melanoma+by+reversible+nitrosylation+of+TSC2.">Inducible nitric oxide synthase drives mTOR pathway activation and proliferation of human melanoma by reversible nitrosylation of TSC2.</a> Cancer Res. 74 (4), 1067-1078 (2014).</li><li>Balke, 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=A+short-term+in+vivo+model+for+giant+cell+tumor+of+bone.">A short-term in vivo model for giant cell tumor of bone.</a> BMC Cancer. 11, 241 (2011).</li><li>Balke, 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=Morphologic+characterization+of+osteosarcoma+growth+on+the+chick+chorioallantoic+membrane.">Morphologic characterization of osteosarcoma growth on the chick chorioallantoic membrane.</a> BMC Res Notes. 3, 58 (2010).</li><li>Sys, G. 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(33), (2009).</li><li>Ossowski, L., Reich, E. <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+for+quantitative+study+of+metastasis.">Experimental model for quantitative study of metastasis.</a> Cancer Res. 40 (7), 2300-2309 (1980).</li><li>Ghanekar, A., Ahmed, S., Chen, K., Adeyi, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endothelial+cells+do+not+arise+from+tumor-initiating+cells+in+human+hepatocellular+carcinoma.">Endothelial cells do not arise from tumor-initiating cells in human hepatocellular carcinoma.</a> BMC Cancer. 13, 485 (2013).</li><li>Ho, J. 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Several key steps in this protocol most likely account for the improved embryonic survival as well as increased reliability of tumor growth. Dropping the CAM away from the shell by applying suction to the air sac is less invasive than other existing methods (using a needle to remove albumin from the egg, blunt dissection, etc.). Using a sterile push pin to create the two small holes required for this method is the most challenging part of the protocol. Using too much force can result in damage to the CAM and its vasculat...

Hepatocellular carcinoma (HCC) is the 3rd leading cause of cancer mortality in the world1. Currently only 30% of HCC patients are eligible for potentially curative surgical treatments2, and systemic chemotherapy is not efficacious3. Therefore, there is a pressing unmet clinical need for novel HCC therapies, and the development of model systems suitable for efficient testing of new agents. The chick chorioallantoic membrane (CAM) assay provides a reproducible, cost-effective, and fast medium-throughput method of testing potential anti-tumor drugs in vivo.
The CAM assay has been used extensively to study angiogenesis4. It has also been successfully developed into a tumor xenograft model of cancers, including glioblastoma5, pancreatic cancer6, melanoma7-9, and osteosarcoma10-11. Both in ovo12 and ex ovo13 techniques have been utilized in the literature, with details varying from protocol to protocol. One major challenge to the CAM xenograft model is the relatively high incidence of embryonic death after manipulation of the egg, with published chick embryo mortality rates ranging from 25 - 50 percent11-14.
In this article, we describe the development of an in ovo xenograft model of HCC that reliably produces growth of three-dimensional, vascularized tumors that histologically resemble undifferentiated HCC. We have adapted a protocol first described by Ossowski et al.14 and have achieved chick embryonic survival rates of up to 93% with extremely high tumor engraftment.

<table border="0" cellpadding="0" cellspacing="0" width="1094">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:401px;">Name of Reagent/ Equipment</td>
			<td style="width:108px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:467px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:401px;">Premium incubated eggs</td>
			<td style="width:108px;">Charles River</td>
			<td style="width:119px;">N/A</td>
			<td>http://www.criver.com/files/pdfs/avian/av_c_spf_egg_price_list.aspx</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:401px;">Egg incubators</td>
			<td style="width:108px;">GQF</td>
			<td style="width:119px;">Hova-Bator 2362N</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:401px;">Rotating egg trays</td>
			<td style="width:108px;">GQF</td>
			<td style="width:119px;">1611 Automatic Egg Turner</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:401px;">Egg candler</td>
			<td style="width:108px;">Lyon</td>
			<td style="width:119px;">Hi-Power 950-070</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:401px;">Dremel 100 rotary tool with 15/16 cut-off wheel</td>
			<td style="width:108px;">Dremel</td>
			<td style="width:119px;">100-N/7</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:401px;">Sterile forceps, push pin, dissection scissors, Scotch tape</td>
			<td style="width:108px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:401px;">Matrigel</td>
			<td style="width:108px;">BD Biosciences</td>
			<td style="width:119px;">356234</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:401px;">Cryogenic vials, external thread with silicone washer</td>
			<td style="width:108px;">Corning</td>
			<td style="width:119px;">430659</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:401px;">Collagenase from Clostridium histolyticum</td>
			<td style="width:108px;">Sigma</td>
			<td style="width:119px;">C9891</td>
			<td></td>
		</tr>
	</tbody>
</table>

the in ovo chick chorioallantoic membrane (cam) assay as an efficient xenograft model of hepatocellular carcinoma

The chick chorioallantoic membrane (CAM) begins to develop by day 7 after fertilization and matures by day 12. The CAM is naturally immunodeficient and highly vascularized, making it an ideal system for tumor implantation. Furthermore, the CAM contains extracellular matrix proteins such as fibronectin, laminin, collagen, integrin alpha(v)beta3, and MMP-2, making it an attractive model to study tumor invasion and metastasis. Scientists have long taken advantage of the physiology of the CAM by using it as a model of angiogenesis. More recently, the CAM assay has been modified to work as an in vivo xenograft model system for various cancers that bridges the gap between basic in vitro work and more complex animal cancer models. The CAM assay allows for the study of tumor growth, anti-tumor therapies, and pro-tumor molecular pathways in a biologically relevant system that is both cost- and time-effective. Here, we describe the development of CAM xenograft model of hepatocellular carcinoma (HCC) with embryonic survival rates of up to 93% and reliable tumor take leading to growth of three-dimensional, vascularized tumors.

Representative pictures of key steps in the protocol are shown here. Figure 1A demonstrates the use of the candler to visualize the developing embryo, the air sac, and the vasculature of the CAM. Figure 1B-1C show the process of dropping the CAM by making the two holes and then applying negative pressure using the safety bulb, and Figure 1D shows a successfully dropped CAM with a large air bubble under the pencil-marked hole. Figure 1E and Figure...

Watch this Scientific Journal Video about The In Ovo Chick Chorioallantoic Membrane CAM Assay as an Efficient Xenograft Model of Hepatocellular Carcinoma at JoVE.com

The In Ovo Chick Chorioallantoic Membrane CAM Assay as an Efficient Xenograft Model of Hepatocellular Carcinoma

The chick chorioallantoic membrane (CAM) is immunodeficient and highly vascularized, making it a natural in vivo model of tumor growth and angiogenesis. In this protocol, we describe a reliable method of growing three-dimensional, vascularized hepatocellular carcinoma (HCC) tumors using the CAM assay.

The In Ovo Chick Chorioallantoic Membrane (CAM) Assay as an Efficient Xenograft Model of Hepatocellular Carcinoma

The chick chorioallantoic membrane (CAM) begins to develop by day 7 after fertilization and matures by day 12. The CAM is naturally immunodeficient and ...

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34.8K Views.  Icahn School of Medicine at Mount Sinai. The chick chorioallantoic membrane (CAM) is immunodeficient and highly vascularized, making it a natural in vivo model of tumor growth and angiogenesis. In this protocol, we describe a reliable method of growing three-dimensional, vascularized hepatocellular carcinoma (HCC) tumors using the CAM assay.