Name: utilization of ultrasound guided tissue-directed cellular implantation for the establishment of biologically relevant metastatic tumor xenografts
Uploaded: 2018-05-25T14:30:00
Description: Watch this Scientific Journal Video about Utilization of Ultrasound Guided Tissue-directed Cellular Implantation for the Establishment of Biologically Relevant Metastatic Tumor Xenografts at JoVE.com

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...

Watch this Scientific Journal Video about Utilization of Ultrasound Guided Tissue-directed Cellular Implantation for the Establishment of Biologically Relevant Metastatic Tumor Xenografts at JoVE.com

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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Research

JoVE Journal

Cancer Research

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 ...

Advanced Animal Model of Colorectal Metastasis in Liver: Imaging Techniques and Properties of Metastatic Clones

Patients with a limited number of hepatic metastases and slow rates of progression can be successfully treated with local treatment approaches1,2. However, little is known about the heterogeneity of liver metastases, and animal models capable of evaluating the development of individual metastatic colonies are needed. Here, we present an advanced model of hepatic metastases that provides the ability to quantitatively visualize the development of individual tumor clones in the liver and estimate their growth kinetics and colonization efficiency. We generated a panel of monoclonal derivatives of HCT116 human colorectal cancer cells stably labeled with luciferase and tdTomato and possessing different growth properties. With a splenic injection followed by a splenectomy, the majority of these clones are able to generate hepatic metastases, but with different frequencies of colonization and varying growth rates. Using the In Vivo&#160;Imaging System (IVIS), it is possible to visualize and quantify metastasis development with in vivo luminescent and ex vivo fluorescent imaging. In addition, Diffuse Luminescent Imaging Tomography (DLIT) provides a 3D distribution of liver metastases in vivo. Ex vivo fluorescent imaging of harvested livers provides quantitative measurements of individual hepatic metastatic colonies, allowing for the evaluation of the frequency of liver colonization and the growth kinetics of metastases. Since the model is similar to clinically observed liver metastases, it can serve as a modality for detecting genes associated with liver metastasis and for testing potential ablative or adjuvant treatments for liver metastatic disease.

The ability of metastatic clones to colonize distant sites depends on their proliferation capacity and/or their ability to survive in the host microenvironment without significant proliferation. Here, we present an animal model that allows quantitative visualization of both types of liver colonization by metastatic clones.

Patients with a limited number of hepatic metastases and slow rates of progression can be successfully treated with local treatment approaches1,2. ...

Endobronchial Ultrasound-guided Intratumoral Injection of Cisplatin for the Treatment of Isolated Mediastinal Recurrence of Lung Cancer

Isolated hilar and mediastinal recurrence (IMHR) following external beam radiation therapy (EBRT) in patients with lung cancer is common. These patients do not have many treatment options and are usually offered palliative chemotherapy or best supportive care. Endobronchial ultrasound (EBUS)-guided intratumoral injection of cisplatin (ITC) is a novel approach for these patients. The procedure is performed under conscious sedation. The lesion is located with a bronchoscopy using EBUS, and a 22-gauge EBUS needle is advanced through the working channel of the scope and locked in position. Under ultrasound guidance, the wall of the tracheobronchial tree is punctured and the needle is moved into the target lesion. The needle stylet is then removed and cisplatin (40 mg/40 mL) is injected into the lesion. One to two sites are treated per session. Details of the procedure are described in the protocol section of paper. At our center, 50 sites were treated in 36 patients (19 males, 17 females). The mean age of our cohort was 61.9 &#177;8.5 years. We performed final analyses on 35 patients and 41 sites. 24/35 (69%) had complete or partial response (responders), whereas 11/35 (31%) had stable or progressive disease (non-responders). Overall, survival in our group was 8 months (95% CI of 6-11 months), with patients who responded having significantly better survival than the ones who did not.

The management of isolated recurrent lung cancer in a previously-irradiated field is challenging. Here, we describe an endobronchial ultrasound (EBUS)-guided cisplatin injection for the management of patients with localized lung cancer recurrence in a previously-radiated field.

Isolated hilar and mediastinal recurrence (IMHR) following external beam radiation therapy (EBRT) in patients with lung cancer is common. These patients ...

Labeling of Breast Cancer Patient-derived Xenografts with Traceable Reporters for Tumor Growth and Metastasis Studies

The use of preclinical models to study tumor biology and response to treatment is central to cancer research. Long-established human cell lines, and many transgenic mouse models, often fail to recapitulate the key aspects of human malignancies. Thus, alternative models that better represent the heterogeneity of patients' tumors and their metastases are being developed. Patient-derived xenograft (PDX) models in which surgically resected tumor samples are engrafted into immunocompromised mice have become an attractive alternative as they can be transplanted through multiple generations,and more efficiently reflect tumor heterogeneity than xenografts derived from human cancer cell lines. A limitation to the use of PDXs is that they are difficult to transfect or transduce to introduce traceable reporters or to manipulate gene expression. The current protocol describes methods to transduce dissociated tumor cells from PDXs with high transduction efficiency, and the use of labeled PDXs for experimental models of breast cancer metastases. The protocol also demonstrates the use of labeled PDXs in experimental metastasis models to study the organ-colonization process of the metastatic cascade. Metastases to different organs can be easily visualized and quantified using bioluminescent imaging in live animals, or GFP expression during dissection and in excised organs. These methods provide a powerful tool to extend the use of multiple types of PDXs to metastasis research.

We describe a method for stable labeling of patient-derived xenografts (PDXs) with lentiviral particles expressing green-fluorescent protein and luciferase reporters. This method allows for tracking the growth of PDXs at the primary site, as well as detecting spontaneous and experimental metastases using in vivo imaging systems.

The use of preclinical models to study tumor biology and response to treatment is central to cancer research. Long-established human cell lines, and many ...

The Establishment of a Lung Colonization Assay for Circulating Tumor Cell Visualization in Lung Tissues

Metastasis is the major cause of cancer death. The role of circulating tumor cells (CTCs) in promoting cancer metastasis, in which lung colonization by CTCs critically contributes to early lung metastatic processes, has been vigorously investigated. As such, animal models are the only approach that captures the full systemic process of metastasis. Given that problems occur in previous experimental designs for examining the contributions of CTCs to blood vessel extravasation, we established an in vivo lung colonization assay in which a long-term-fluorescence cell-tracer, carboxyfluorescein succinimidyl ester (CFSE), was used to label suspended tumor cells and lung perfusion was performed to clear non-specifically trapped CTCs prior to lung removal, confocal imaging, and quantification. Polymeric fibronectin (polyFN) assembled on CTC surfaces has been found to mediate lung colonization in the final establishment of metastatic tumor tissues. Here, to specifically test the requirement of polyFN assembly on CTCs for lung colonization and extravasation, we performed short term lung colonization assays in which suspended Lewis lung carcinoma cells (LLCs) stably expressing FN-shRNA (shFN) or scramble-shRNA (shScr) and pre-labeled with 20 &#956;M of CFSE were intravenously inoculated into C57BL/6 mice. We successfully demonstrated that the abilities of shFN LLC cells to colonize the mouse lungs were significantly diminished in comparison to shScr LLC cells. Therefore, this short-term methodology may be widely applied to specifically demonstrate the ability of CTCs within the circulation to colonize the lungs.

An animal model is needed to decipher the role of circulating tumor cells (CTCs) in promoting lung colonization during cancer metastasis. Here, we established and successfully performed an in vivo assay to specifically test the requirement of polymeric fibronectin (polyFN) assembly on CTCs for lung colonization.

Metastasis is the major cause of cancer death. The role of circulating tumor cells (CTCs) in promoting cancer metastasis, in which lung colonization by ...

Micromanipulation of Circulating Tumor Cells for Downstream Molecular Analysis and Metastatic Potential Assessment

Blood-borne metastasis accounts for&#160;most cancer-related deaths and involves circulating tumor cells (CTCs) that are successful in establishing new tumors at distant sites. CTCs are found in the bloodstream of patients as single cells (single CTCs) or as multicellular aggregates (CTC clusters and CTC-white blood cell clusters), with the latter displaying a higher metastatic ability. Beyond enumeration, phenotypic and molecular analysis is extraordinarily important to dissect CTC biology and to identify actionable vulnerabilities. Here, we provide a detailed description of a workflow that includes CTC immunostaining and micromanipulation, ex vivo culture to assess&#160;proliferative and survival capabilities of individual cells, and in vivo metastasis-formation assays. Additionally, we provide a protocol to achieve the dissociation of CTC clusters into individual cells and the investigation of intra-cluster heterogeneity. With these approaches, for instance, we precisely quantify survival and proliferative potential of single CTCs and individual cells within CTC clusters, leading us to the observation that cells within clusters display better survival and proliferation in ex vivo cultures compared to single CTCs. Overall, our workflow offers a platform to dissect the characteristics of CTCs at the single cell level, aiming towards the identification of metastasis-relevant pathways and a better understanding of CTC biology.

Here, we present an integrated workflow to identify phenotypic and molecular features that characterize circulating tumor cells (CTCs). We combine live immunostaining and robotic micromanipulation of single and clustered CTCs with single cell-based techniques for downstream analysis and assessment of metastasis-seeding ability.

Blood-borne metastasis accounts for&#160;most cancer-related deaths and involves circulating tumor cells (CTCs) that are successful in establishing new ...

In Vivo Imaging and Quantitation of the Host Angiogenic Response in Zebrafish Tumor Xenografts

Tumor angiogenesis is a key target of anti-cancer therapy and this method has been developed to provide a new model to study this process in vivo. A zebrafish xenograft is created by implanting mammalian tumor cells into the perivitelline space of two days-post-fertilization zebrafish embryos, followed by measuring the extent of the angiogenic response observed at an experimental endpoint up to two days post-implantation. The key advantage to this method is the ability to accurately quantitate the zebrafish host angiogenic response to the graft. This enables detailed examination of the molecular mechanisms as well as the host vs tumor contribution to the angiogenic response. The xenografted embryos can be subjected to a variety of treatments, such as incubation with potential anti-angiogenesis drugs, in order to investigate strategies to inhibit tumor angiogenesis. The angiogenic response can also be live-imaged in order to examine more dynamic cellular processes. The relatively undemanding experimental technique, cheap maintenance costs of zebrafish and short experimental timeline make this model especially useful for the development of strategies to manipulate tumor angiogenesis.

The aim of this method is to generate an in vivo model of tumor angiogenesis by xenografting mammalian tumor cells into a zebrafish embryo that has fluorescently-labelled blood vessels. By imaging the xenograft and associated vessels, a quantitative measurement of the angiogenic response can be obtained.

Tumor angiogenesis is a key target of anti-cancer therapy and this method has been developed to provide a new model to study this process in vivo. A ...

Ultrasound-Guided Orthotopic Implantation of Murine Pancreatic Ductal Adenocarcinoma

The recent success of immune checkpoint blockade in melanoma and lung adenocarcinoma has galvanized the field of immuno-oncology as well as revealed the limitations of current treatments, as the majority of patients do not respond to immunotherapy. Development of accurate preclinical models to quickly identify novel and effective therapeutic combinations are critical to address this unmet clinical need. Pancreatic ductal adenocarcinoma (PDA) is a canonical example of an immune checkpoint blockade resistant tumor with only 2% of patients responding to immunotherapy. The genetically engineered KrasG12D+/-;Trp53R172H+/-;Pdx-1 Cre (KPC) mouse model of PDA recapitulates human disease and is a valuable tool for assessing therapies for immunotherapy resistant in the preclinical setting, but time to tumor onset is highly variable. Surgical orthotopic tumor implantation models of PDA maintain the immunobiological hallmarks of the KPC tissue-specific tumor microenvironment (TME) but require a time-intensive procedure and introduce aberrant inflammation. Here, we use an ultrasound-guided orthotopic tumor implantation model (UG-OTIM) to non-invasively inject KPC-derived PDA cell lines directly into the mouse pancreas. UG-OTIM tumors grow in the endogenous tissue site, faithfully recapitulate histological features of the PDA TME, and reach enrollment-sized tumors for preclinical studies by four weeks after injection with minimal seeding on the peritoneal wall. The UG-OTIM system described here is a rapid and reproducible tumor model that may allow for high throughput analysis of novel therapeutic combinations in the murine PDA TME.

We describe a protocol for the ultrasound guided implantation of murine-derived pancreatic ductal adenocarcinoma cell lines directly into the native tumor site. This approach resulted in pancreatic tumors detectable by ultrasound scanning within 2-4 weeks of injection, and significantly reduced the proportion tumor cell seeding on the peritoneal wall as compared to surgical orthotopic implantation.

The recent success of immune checkpoint blockade in melanoma and lung adenocarcinoma has galvanized the field of immuno-oncology as well as revealed the ...

Detection of Lung Tumor Progression in Mice by Ultrasound Imaging

With ~1.6 million victims per year, lung cancer contributes tremendously to the worldwide burden of cancer. Lung cancer is partly driven by genetic alterations in oncogenes such as the KRAS oncogene, which constitutes ~25% of lung cancer cases. The difficulty in therapeutically targeting KRAS-driven lung cancer partly stems from having poor models that can mimic the progression of the disease in the lab. We describe a method that permits the relative quantification of primary KRAS lung tumors in a Cre-inducible LSL-KRAS G12D mouse model via ultrasound imaging. This method relies on brightness (B)-mode acquisition of the lung parenchyma. Tumors that are initially formed in this model are visualized as B-lines and can be quantified by counting the number of B-lines present in the acquired images. These would represent the relative tumor number formed on the surface of the mouse lung. As the formed tumors develop with time, they are perceived as deep clefts within the lung parenchyma. Since the circumference of the formed tumor is well-defined, calculating the relative tumor volume is achieved by measuring the length and width of the tumor and applying them in the formula used for tumor caliper measurements. Ultrasound imaging is a non-invasive, fast and user-friendly technique that is often used for tumor quantifications in mice. Although artifacts may appear when obtaining ultrasound images, it has been shown that this imaging technique is more advantageous for tumor quantifications in mice compared to other imaging techniques such as computed tomography (CT) imaging and bioluminescence imaging (BLI). Researchers can investigate novel therapeutic targets using this technique by comparing lung tumor initiation and progression between different groups of mice.

This protocol describes the steps taken to induce KRAS lung tumors in mice as well as the quantification of formed tumors by ultrasound imaging. Small tumors are visualized in early timepoints as B-lines. At later timepoints, relative tumor volume measurements are achieved by the measurement tool in the ultrasound software.

With ~1.6 million victims per year, lung cancer contributes tremendously to the worldwide burden of cancer. Lung cancer is partly driven by genetic ...

Drug Screening of Primary Patient Derived Tumor Xenografts in Zebrafish

Patient derived xenograft models are critical in defining how different cancers respond to drug treatment in an in vivo system. Mouse models are the standard in the field, but zebrafish have emerged as an alternative model with several advantages, including the ability for high-throughput and low-cost drug screening. Zebrafish also allow for in vivo drug screening with large replicate numbers that were previously only obtainable with in vitro systems. The ability to rapidly perform large scale drug screens may open up the possibility for personalized medicine with rapid translation of results back to clinic. Zebrafish xenograft models could also be used to rapidly screen for actionable mutations based on tumor response to targeted therapies or to identify new anti-cancer compounds from large libraries. The current major limitation in the field has been quantifying and automating the process so that drug screens can be done on a larger scale and be less labor-intensive. We have developed a workflow for xenografting primary patient samples into zebrafish larvae and performing large scale drug screens using a fluorescence microscope equipped imaging unit and automated sampler unit. This method allows for standardization and quantification of engrafted tumor area and response to drug treatment across large numbers of zebrafish larvae. Overall, this method is advantageous over traditional cell culture drug screening as it allows for growth of tumor cells in an in vivo environment throughout drug treatment, and is more practical and cost-effective than mice for large scale in vivo drug screens.

Zebrafish xenograft models allow for high-throughput drug screening and fluorescent imaging of human cancer cells in an in vivo microenvironment. We developed a workflow for large scale, automated drug screening on patient-derived leukemia samples in zebrafish using an automated fluorescence microscope equipped imaging unit.

Patient derived xenograft models are critical in defining how different cancers respond to drug treatment in an in vivo system. Mouse models are the ...