This work received support from the Robert Wood Johnson Foundation/Amos Medical Faculty Development Program, Taubman Research Institute, and the Section of Pediatric Surgery, The University of Michigan. The authors wish to thank Kimber Converso-Baran and Dr. Marcus Jarboe for the assistance with ultrasound injection procedures and the imaging platform. We thank Paul Trombley for his assistance with figure graphics. We also thank the Department of Radiology at The University of Michigan for the use of The Center for Molecular Imaging and the Tumor Imaging Core, which are supported in part by Comprehensive Cancer Center NIH, grant P30 CA046592. The University of Michigan Physiology Phenotyping Core that is supported in part by grant funding from the NIH (OD016502) and the Frankel Cardiovascular Center. Cell line authentication was done at IDEXX RADIL Bioresearch Facilities, Columbia, MO. We thank Tammy Stoll, Dr. Rajen Mody and the Mott Solid Tumor Oncology Program. Our patients and families are gratefully acknowledged for their inspiration, courage, and ongoing support of our research.

All work was done in accordance with The University of Michigan Institutional Review Board (HUM 00052430) and conforms to procedures approved by the University Committee on Use and Care of Animals (UCUCA). The Unit for Laboratory of Animal Medicine (ULAM) oversaw animal care.
All work was done with approval from The University of Michigan Institutional Review Board (HUM 00052430) and conforms to all human research ethics committee regulations.&#160;Human cells are considered to be a potentiall...

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Ultrasound-guided implantation of NB and ES cells is an efficient and safe method to establish reliable murine xenografts for preclinical studies in cancer biology. Critical to the success of ultrasound-guided tissue-targeted implantation is the presence and availability of trained personnel with expertise in anatomically localizing the organ of interest and in stereotactic injection of tumor cells.
The dissociation of tumor tissue proved to be a crucial step in developing the described patien...

Animal xenograft models are essential tools for preclinical studies of novel anticancer therapies. Standard murine xenografts rely on subcutaneous flank implantation of cells, providing an efficient and easily accessible site for monitoring tumor growth. The disadvantage of subcutaneous models is their lack of tumor-specific biologic characteristics, which may limit their potential to metastasize1. Such limitations are overcome by the use of orthotopic xenografts in which tumor cells are engrafted at native tissue sites, providing a relevant microenvironment with metastatic potential2. Orthotopic xenograft models maintain original biological features and provide reliable models for preclinical drug discovery3,4. The cancer cells utilized for tissue-directed implantation are either established cell lines or patient-derived cells from patient tumors. Xenografts established from cancer cell lines may exhibit high genetic divergence from the primary tumor compared to patient derived xenografts5. Given this, the establishment of patient-derived orthotopic xenografts has become the preferred standard for testing novel therapeutics in cancer drug discovery.
In the pediatric cancer neuroblastoma (NB), orthotopic xenograft models recapitulate primary tumor biology and develop metastasis to typical sites of NB spread6,7. NB develops in the adrenal gland or along the paravertebral sympathetic chain. The most common methods of orthotopic implantation require open trans-abdominal surgical procedures. Such methods are often tedious, have high animal morbidity, and complex recovery periods. High-resolution ultrasound has been recently utilized for tissue-directed implantation of tumor cells in development of several murine models for cancer research8,9. The technique is reliable, reproducible, efficient, and safe for the establishment of relevant metastatic tumor xenografts10,11.
The establishment of pediatric cancer xenografts by ultrasound-guided target organ localization and needle implantation of cell lines and patient-derived tumor cells is demonstrated11. The technique was utilized for NB targeted to the murine adrenal gland. Ewing&#39;s sarcoma (ES) is predominantly an osseous cancer, commonly seen in the long bones such as femur and pelvic bones12. Case reports have shown that to determine whether growth of a predominantly osseous cancer is feasible in renal tissue, a renal sub capsular location was chosen for orthotopic implantation13. Renal sub capsular cell implantation of tumor cells has been utilized as a promising model to study spontaneous metastases for ES14.

<table border="0" cellpadding="0" cellspacing="0" width="1053">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Mice</td>
			<td style="width:231px;"></td>
			<td style="width:232px;"></td>
			<td style="width:295px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">NOD-SCID</td>
			<td>Charles River</td>
			<td>394</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">NSG</td>
			<td>The Jackson Laboratory</td>
			<td>5557</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Cell Line&#160;</td>
			<td style="width:231px;"></td>
			<td style="width:232px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">NB</td>
			<td style="width:231px;"></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">IMR-32</td>
			<td style="width:231px;">ATCC</td>
			<td>CCL-127</td>
			<td>Established human neuroblastoma cell line</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">SH-SY5Y</td>
			<td style="width:231px;">ATCC</td>
			<td style="width:232px;">CRL-2266</td>
			<td>Established human neuroblastoma cell line</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">SK-N-Be2</td>
			<td style="width:231px;">ATCC</td>
			<td style="width:232px;">CRL-2271</td>
			<td>Established human neuroblastoma cell line</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">ES</td>
			<td style="width:231px;"></td>
			<td style="width:232px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">TC32&#160;</td>
			<td style="width:231px;">COGcell.ORG</td>
			<td style="width:232px;"></td>
			<td>Established human Ewing&#39;s Sarcoma cell line</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">A673</td>
			<td style="width:231px;">COGcell.ORG</td>
			<td style="width:232px;"></td>
			<td>Established human Ewing&#39;s Sarcoma cell line</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">CHLA-25</td>
			<td style="width:231px;">COGcell.ORG</td>
			<td style="width:232px;"></td>
			<td>Established human Ewing&#39;s Sarcoma cell line</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">A4573</td>
			<td style="width:231px;">COGcell.ORG</td>
			<td style="width:232px;"></td>
			<td>Established human Ewing&#39;s Sarcoma cell line</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Cell Line media</td>
			<td style="width:231px;"></td>
			<td style="width:232px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">RPMI</td>
			<td style="width:231px;">Life Technologies</td>
			<td style="width:232px;">11875-093</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Matrigel</td>
			<td style="width:231px;">BD BioSciences</td>
			<td>354234</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Dissociation</td>
			<td style="width:231px;"></td>
			<td style="width:232px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Dissection Tools</td>
			<td style="width:231px;">KentScientific</td>
			<td style="width:232px;">INSMOUSEKIT</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Human Tumor Dissociation Kit&#160;</td>
			<td style="width:231px;">MACS Miltenyi Biotec</td>
			<td style="width:232px;">130-095-929</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">gentleMACS dissociator</td>
			<td style="width:231px;">MACS Miltenyi Biotec</td>
			<td>130-093-235</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">gentleMACS C tubes</td>
			<td style="width:231px;">MACS Miltenyi Biotec</td>
			<td>130-096-334</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Cell Strainer</td>
			<td style="width:231px;">Corning</td>
			<td>431751</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Luciferase Tagging</td>
			<td style="width:231px;"></td>
			<td style="width:232px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:296px;">Lenti-GFP1 virus</td>
			<td style="width:231px;">University of Michigan, Vector Core</td>
			<td style="width:232px;"></td>
			<td>Luciferase Virus</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Steady Glo-Luciferase Assay Kit</td>
			<td style="width:231px;">Promega</td>
			<td>E2510</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Bioluminescence Imaging</td>
			<td style="width:231px;"></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Ivis Spectrum Imaging System</td>
			<td style="width:231px;">PerkinElmer</td>
			<td>124262</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">D-Luciferin</td>
			<td style="width:231px;">Promega</td>
			<td>E160X</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Anesthetic</td>
			<td style="width:231px;"></td>
			<td style="width:232px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Inhaled Isoflurane&#160;</td>
			<td style="width:231px;">Piramal Critical Care Inc</td>
			<td style="width:232px;">66794-0017-25</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Ultrasound Guided Injection</td>
			<td style="width:231px;"></td>
			<td style="width:232px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Vevo 2100 High Resolution Imaging</td>
			<td style="width:231px;">Vevo</td>
			<td style="width:232px;">2100</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Hamilton Syringes (27 gauge needle)</td>
			<td style="width:231px;">Hamilton</td>
			<td style="width:232px;">80000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">22 Gauge Angiocatheter</td>
			<td style="width:231px;">BD Biosciences</td>
			<td style="width:232px;">381423</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Optical ointment</td>
			<td style="width:231px;">Major Pharmaceuticals</td>
			<td style="width:232px;">301909</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Nair</td>
			<td style="width:231px;">Church &#38; Dwight Co</td>
			<td style="width:232px;"></td>
			<td style="width:295px;">Hair Removal agent</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:296px;">Aquasonic 100 Ultrasound Transmission gel</td>
			<td style="width:231px;">Parker</td>
			<td style="width:232px;"></td>
			<td>Ultrasound gel</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Histology</td>
			<td style="width:231px;"></td>
			<td style="width:232px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">CD99</td>
			<td style="width:231px;">DAKO</td>
			<td>M3601</td>
			<td>Primary Antibody</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Tyrosine Hydroxylase</td>
			<td style="width:231px;">Sigma-Aldrich</td>
			<td>T2928</td>
			<td>Primary Antibody</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Secondary HRP-Polymer antibody</td>
			<td style="width:231px;">Biocare</td>
			<td>BRR4056KG</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Miscelleneous</td>
			<td style="width:231px;"></td>
			<td style="width:232px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">10 mL Pipettes</td>
			<td style="width:231px;">Fisher Scientific</td>
			<td style="width:232px;">13-676-10J</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">5 mL Pipettes</td>
			<td style="width:231px;">Fisher Scientific</td>
			<td style="width:232px;">13-676-10H</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">1.5 mL Microcentrifuge tubes</td>
			<td style="width:231px;">Fisher Scientific</td>
			<td style="width:232px;">05-408-129</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">P1000 pipette</td>
			<td style="width:231px;">Eppendorf</td>
			<td style="width:232px;">3120000062</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">P200 pipette</td>
			<td style="width:231px;">Eppendorf</td>
			<td style="width:232px;">3120000054</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">P1000 pipette tips</td>
			<td style="width:231px;">Fisher Scientific</td>
			<td style="width:232px;">21-375E</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">P200 pipette tips</td>
			<td style="width:231px;">Fisher Scientific</td>
			<td style="width:232px;">21-375D</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Portable pipette aid</td>
			<td style="width:231px;">Drummond</td>
			<td>4-000-101</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">digital animal Weighing Scale&#160;</td>
			<td style="width:231px;">KentScientific</td>
			<td style="width:232px;">SCL-1015</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Calipers</td>
			<td style="width:231px;">Fisher Scientific</td>
			<td style="width:232px;">06-664-16</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">6well low attachment plates</td>
			<td style="width:231px;">Corning</td>
			<td style="width:232px;">07-200-601</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">10 cm Tissue Culture Treated Dishes</td>
			<td style="width:231px;">Fisher Scientific</td>
			<td style="width:232px;">FB012924</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:296px;">Polybrene</td>
			<td style="width:231px;">Sigma-Aldrich</td>
			<td style="width:232px;">TR-1003-G</td>
			<td></td>
		</tr>
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utilization of ultrasound guided tissue-directed cellular implantation for the establishment of biologically relevant metastatic tumor xenografts

Preclinical testing of anticancer therapies relies on relevant xenograft models that mimic the innate tendencies of cancer. Advantages of standard subcutaneous flank models include procedural ease and the ability to monitor tumor progression and response without invasive imaging. Such models are often inconsistent in translational clinical trials and have limited biologically relevant characteristics with low proclivity to produce metastasis, as there is a lack of a native microenvironment. In comparison, orthotopic xenograft models at native tumor sites have been shown to mimic the tumor microenvironment and replicate important disease characteristics such as distant metastatic spread. These models often require tedious surgical procedures with prolonged anesthetic time and recovery periods. To address this, cancer researchers have recently utilized ultrasound-guided injection techniques to establish cancer xenograft models for preclinical experiments, which allows for rapid and reliable establishment of tissue-directed murine models. Ultrasound visualization also provides a noninvasive method for longitudinal assessment of tumor engraftment and growth. Here, we describe the method for ultrasound-guided injection of cancer cells, utilizing the adrenal gland for NB and renal sub capsule for ES. This minimally invasive approach overcomes tedious open surgery implantation of cancer cells in tissue-specific locations for growth and metastasis, and abates morbid recovery periods. We describe the utilization of both established cell lines and patient derived cell lines for orthotopic injection. Pre-made commercial kits are available for tumor dissociation and luciferase tagging of cells. Injection of cell suspension using image-guidance provides a minimally invasive and reproducible platform for the creation of preclinical models. This method is utilized to create reliable preclinical models for other cancers such as bladder, liver and pancreas exemplifying its untapped potential for numerous cancer models.

Using the procedures presented, ultrasound-guided implantation of NB cells into the adrenal gland was done in a dedicated procedure room equipped with a heated surgical table. Arm and foot pads were placed for monitoring murine heart activity (Figure 1A). The animal remained anesthetized under isoflurane using nose cone inhalation. Using a high-resolution ultrasound probe, the left kidney was identified with the adrenal gland just cranial to the kidney (<stro...

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Utilization of Ultrasound Guided Tissue-directed Cellular Implantation for the Establishment of Biologically Relevant Metastatic Tumor Xenografts

Here, we present a protocol to utilize ultrasound-guided injection of neuroblastoma (NB) and Ewing's sarcoma (ES) cells (established cell lines and patient-derived tumor cells) at biologically relevant sites to create reliable preclinical models for cancer research.

Preclinical testing of anticancer therapies relies on relevant xenograft models that mimic the innate tendencies of cancer. Advantages of standard ...

The goal of this method is to establish biologically relevant cancer orthotopic xenografts for preclinical studies. Patient-derived neuroblastoma cells are injected into the murine adrenal gland by ultrasound guidance without open surgery or prolonged recovery. This method can help answer critical questions in cancer biology and in translational research, such as studies of tumor evolution, therapeutic responses in the native microenvironment and metastases.Such a knowledge would greatly improve the reliability of preclinical studies and facilitate drug discovery. The main advantage of this technique is that it is patient-derived, tissue-directed, efficient, and reliable in producing an orthotopic xenographed model for cancer therapy research. Demonstrating the critical steps in the procedure will be Sahiti Chukkapalli, a senior technician and our lab manager, along with Tina Thomas, a research fellow in our laboratory.Generate a single, patient-derived cancer cell suspension from tumor tissue using a tumor dissociation kit. Begin by transferring approximately half a gram of tumor tissue to a 100 millimeter cell culture dish containing five milliliters of enzyme supplemented RPMI buffer. Then, use scissors and tissue forceps to mince the tumor into small pieces of two to four millimeters.Pipette the tumor mixture into a dissociater tube and close the tube. Invert the tube, attach onto the sleeve of a tissue dissociater, and dissociate the tissue using the appropriate program. After dissociating, incubate the tumor cell suspension on a rotating rack at 37 degrees Celsius for one hour.Triturate the cell suspension every 15 minutes during the incubation. Following the incubation, transfer the cell suspension to a new 50 milliliter conical tube and add 10 milliliters of RPMI. Then, centrifuge the cell suspension at 314g for five minutes.After the centrifugation, remove the supernatant and suspend the pellet in five milliliters of RPMI. Pass the cell suspension through a 40 micron cell strainer and collect the strained solution into a fresh, 50 milliliter tube. After washing the strainer with five milliliters of RPMI media, centrifuge the cell suspension at 314g for five minutes to collect a pellet.Count the cells using a hemocytometer. Then, suspend the pellet in RPMI to obtain a final concentration of four times 10 to the five cells per 10 microliter volume. Transfer five microliters of this cell suspension per injection to a fresh tube, and the same volume of basement membrane matrix to make 10 microliters of cell solution for each injection and place it on ice.Transfer the mouse to the imaging platform with the abdominal side down. Fit and secure the nose cone to maintain isoflurane anesthesia. Begin the implantation procedure using hair removal lotion and a shaver to depilate the back and flank of a properly anesthetized six to eight week old immune-deficient NSG mouse.Apply optical ointment over the animal's eyes to prevent drying. Then, tape the mouse in place to prevent any inadvertent movement. Next, use ultrasound visualization to identify the murine liver, vena cava, spleen, left kidney, and adjacent left adrenal gland.Load a chilled Hamilton syringe, fitted with a small bore needle, with 10 microliters of cell solution. Then, under ultrasound guidance, gently inserted a chilled 22-gauge catheter through the skin and back muscle, directly into the left adrenal gland to provide a channel for cellular injection. Remove the needle and leave the catheter in place.Visualization of the adrenal gland throughout the insertion of the catheter, along with the needle and its trajectory, is imperative to ensure minimal injury to surrounding structures and organs and lower murine morbidity. Then, guide the syringe through the catheter positioned into the center of the adrenal gland. As the syringe is guided through the catheter, it is important to maintain catheter stability and watch the needle advance.Note that the needle itself extends approximately two millimeters beyond termination of the catheter, its position easily seen on ultrasound. Inject the cells into the targeted adrenal tissue. Leave the needle in place for one to two minutes to allow the basement membrane matrix to set.After the basement membrane matrix has set, slowly remove the needle, followed by the removal of the catheter. Finally, place the mouse into a recovery cage until it regains sufficient consciousness to maintain sternal recumbency before returning to the home cage. Ultrasound imaging monitors in vivo tumor progression.This image shows an ultrasound image of the adrenal gland, one week following injection. Here, luminescence imaging of a neuroblastoma injected mouse one week post-injection, shows readings not indicative of tumor engraftment. After two weeks, ultrasound imaging shows tumor engraftment and progression to an area of approximately 40 square millimeters.Bioluminescence at two weeks post-injection showed radiance measuring 10 to the seventh, which is suggestive of cell uptake and tumor growth correlating with ultrasound findings. Ultrasound imaging eight weeks post-injection showed continued tumor growth with an area measurement of greater than 100 square millimeters. Again, bioluminescence confirmed the ultrasound findings with increased radiance levels of 10 to the nine.3-D ultrasound imaging of the tumor showed a volume greater than 100 cubic millimeters, the baseline that our laboratory utilizes for initiation of preclinical therapeutic trials. Excised tumor grossly measured greater than one centimeter in size, correlating with ultrasound measurements and luminescence signals. This media provides demonstration of how to successfully establish adrenal orthotopic xenographs with patient-derived neuroblastoma cells, utilizing ultrasound guidance.Once mastered, this technique can be done in less than 12 minutes per injection if it is performed properly.

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Cancer Research

8.1K Views.  The University of Michigan Medical School. The goal of this method is to establish biologically relevant cancer orthotopic xenografts for preclinical studies. Patient-derived neuroblastoma cells are injected into the murine adrenal gland by ultrasound guidance without open surgery or prolonged recovery. This method can help answer critical questions in cancer biology and in translational research, such as studies of tumor evolution, therapeutic responses in the native microenvironment and metastases.Such a knowledge would great...

Video: Utilization of Ultrasound Guided Tissue-directed Cellular Implantation for the Establishment of Biologically Relevant Metastatic Tumor Xenografts