This research received no specific grant from public, commercial, or not-for-profit funding agencies.

The present study was performed with approval from the Animal Care and Use Committee of Sichuan University. TPO-cre/ERT2; BrafCA/wt; Trp53&#916;ex2-10/&#916;ex2-10&#160;transgenic mice10 were used in this study (see Table of Materials). The protocol steps can be modified for different animal species&#160;if necessary. Twelve mice, including six females and six males, with a mean age of 93 days, were used here.
1. Experimental preparation
<ol>
	<li>Turn on the ultrasonography system (see Table of Materials) and create a new folder for capturing the images and collecting the data. Select the 40 MHz line probe and click on superficial tissue pattern to activate the superficial tissue transducer. Use the &#34;B-mode&#34; for thyroid imaging (Figure 1A). 
	NOTE: B-mode is the basic ultrasound imaging mode. The appearance of ultrasound images relies on the physical interactions of sound with the tissues in the body. B-mode images are produced as gray images11,12.</li>
	<li>Keep the mice in specific cages with free access to food and water. Place the cage on a supplemental heating device&#160;(see Table of Materials) to ensure thermoregulation.</li>
	<li>Ensure sufficient isoflurane in the vaporizer and O2 in the tank. If the supplies are inadequate, exchange the tanks for new ones.</li>
	<li>Clean the animal imaging platform with sterile saline and switch on the heating button. Verify that the temperature is 38-40 &#176;C before placing the animal on the platform (Figure 1C).</li>
</ol>
2. Animal preparation for imaging
<ol>
	<li>Switch on the isoflurane vaporizer. Transfer the mouse from the cage to the anesthetic box.</li>
	<li>Anesthetize the animal using a mixture of 1%-2% of isoflurane from the vaporizer and oxygen flowing at 0.8&#160;L/min.</li>
	<li>Apply depilatory cream from the chest to the neck, wait 30 secs, and then wipe away the cream and fur completely. Thoroughly rinse the area and surrounding fur with warm sterile saline.</li>
	<li>Place the anesthetized animal on the heated platform. Cover the snout with a nose cone connected to the anesthesia outlet (Figure 2A, B). 
	NOTE: The mouse must be completely sedated within 1-2 min. If the animal is still active, perform prolonged isoflurane induction until the animal no longer shows a pedal withdrawal reflex. Ensure that the animal is breathing stably.</li>
	<li>During imaging, monitor the heart rate of the mouse through the heated platform. 
	NOTE: The ultrasonography imaging system is equipped with a heart rate monitor.</li>
	<li>Use adhesive tape to fix the mouse&#39;s limbs to the heated platform, with the animal in a supine position. Ensure that the nose cone is stably positioned with a constant anesthetic gas flow (1.5 L/min).</li>
	<li>Protect the eyes by applying ophthalmic ointment.</li>
</ol>
3. Tumor imaging
<ol>
	<li>Adjust the imaging system to optimize the resolution. Set up the following parameters: two-dimensional gain, 25-30 dB; image depth, 10 mm; number of focal zones, 3; and center, 3-6 mm. 
	NOTE: For the present study, a 40 MHz probe was used. The B-mode was specified for data acquisition.</li>
	<li>Liberally apply ultrasound gel (see Table of Materials) to the area of bare skin.</li>
	<li>Hold the probe and place it into contact with the ultrasound gel on the chest, and then scan from the chest toward the neck to locate the thyroid (Figure 2C). 
	NOTE: Apply pressure gently while scanning; excessive pressure on the animal&#39;s neck may cause gasping or apnea. This protocol was developed based on handheld scanning, but mechanized scanning can also be performed using a machine to guide the probe, such as an animal imaging platform that moves along the x- and y-axes.</li>
	<li>Scan up and down to identify the tumor&#39;s boundaries and assess its size and shape. 
	NOTE: A healthy thyroid usually appears as a hypoechogenic, homogeneous structure in front of the trachea. Anaplastic tumors cause the thyroid to appear much larger, which can easily be identified by neck scanning (Figure 3).</li>
	<li>Identify the ATC tumors from the trachea and strap muscles depending on the anatomical location and ultrasound echo. 
	NOTE: The strap muscles are located in front of the thyroid and trachea, as well as behind the thyroid. The ultrasound echo of the strap muscles appears higher than that of the ATC, while attenuation exists behind the trachea13.
	<ol>
		<li>Based on the impression of the total tumor, confirm the image section with the largest left-to-right tumor diameter. Press the freeze button, and measure the anteroposterior and left-to-right tumor diameters using the ultrasound caliper. 
		NOTE: The anteroposterior diameter must be measured perpendicularly to the left-to-right tumor diameter (Figure 4). The tumor size of the ATC was calculated by multiplying the anteroposterior diameter by the left-to-right tumor diameter14. As the size of the tumors on the left and right sides was inconsistent, each side of the tumors was calculated separately. The total size of the tumors was obtained by adding the bilateral tumors. The sizes were recorded to observe the growth curve of the ATC.</li>
	</ol>
	</li>
	<li>Save the recording as a cine loop, which facilitates the review of the selected images.</li>
</ol>
4. Animal recovery
<ol>
	<li>After scanning, wipe the ultrasound gel and remove the restraining tape from the animal&#39;s limbs.</li>
	<li>Place the mouse on the supplemental heating device (step 1.2). Lay the animal on its side (Figure 2D).</li>
	<li>After the mouse recovers (~5 min), transfer it back to the cage.</li>
	<li>Clean the ultrasonography system, probe, and platform using a soft cloth and isopropyl alcohol or glutaraldehyde wipes.</li>
	<li>Turn off the imaging system.</li>
</ol>

<ol>
	<li>Maniakas, 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=Evaluation+of+overall+survival+in+patients+with+anaplastic+thyroid+carcinoma,+2000-2019.">Evaluation of overall survival in patients with anaplastic thyroid carcinoma, 2000-2019.</a> JAMA Oncology. 6 (9), 1397-1404 (2020).</li><li>Molinaro, 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=Anaplastic+thyroid+carcinoma:+From+clinicopathology+to+genetics+and+advanced+therapies.">Anaplastic thyroid carcinoma: From clinicopathology to genetics and advanced therapies.</a> Nature Reviews Endocrinology. 13 (11), 644-660 (2017).</li><li>Champa, D., Di Cristofano, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modeling+anaplastic+thyroid+carcinoma+in+the+mouse.">Modeling anaplastic thyroid carcinoma in the mouse.</a> Hormones and Cancer. 6 (1), 37-44 (2015).</li><li>Vitiello, M., Kusmic, C., Faita, F., Poliseno, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+lymph+node+volume+by+ultra-high-frequency+ultrasound+imaging+in+the+Braf/Pten+genetically+engineered+mouse+model+of+melanoma.">Analysis of lymph node volume by ultra-high-frequency ultrasound imaging in the Braf/Pten genetically engineered mouse model of melanoma.</a> Journal of Visualized Experiments. (175), e62527 (2021).</li><li>Wang, Y., 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=Low+intensity+focused+ultrasound+(LIFU)+triggered+drug+release+from+cetuximab-conjugated+phase-changeable+nanoparticles+for+precision+theranostics+against+anaplastic+thyroid+carcinoma.">Low intensity focused ultrasound (LIFU) triggered drug release from cetuximab-conjugated phase-changeable nanoparticles for precision theranostics against anaplastic thyroid carcinoma.</a> Biomaterials Science. 27 (1), 196-210 (2018).</li><li>Mohammed, 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=Early+detection+and+prevention+of+pancreatic+cancer:+Use+of+genetically+engineered+mouse+models+and+advanced+imaging+technologies.">Early detection and prevention of pancreatic cancer: Use of genetically engineered mouse models and advanced imaging technologies.</a> Current Medicinal Chemistry. 19 (22), 3701-3713 (2012).</li><li>Wege, A. 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=High+resolution+ultrasound+including+elastography+and+contrast-enhanced+ultrasound+(CEUS)+for+early+detection+and+characterization+of+liver+lesions+in+the+humanized+tumor+mouse+model.">High resolution ultrasound including elastography and contrast-enhanced ultrasound (CEUS) for early detection and characterization of liver lesions in the humanized tumor mouse model.</a> Clinical Hemorheology and Microcirculation. 52 (2-4), 93-106 (2012).</li><li>Greco, 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=Preclinical+imaging+for+the+study+of+mouse+models+of+thyroid+cancer.">Preclinical imaging for the study of mouse models of thyroid cancer.</a> International Journal of Molecular Sciences. 18 (12), 2731 (2017).</li><li>Renault, G., 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=High-resolution+ultrasound+imaging+of+the+mouse.">High-resolution ultrasound imaging of the mouse.</a> Journal of Radiologie. 87, 1937-1945 (2006).</li><li>McFadden, D. G., 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=p53+constrains+progression+to+anaplastic+thyroid+carcinoma+in+a+Braf-mutant+mouse+model+of+papillary+thyroid+cancer.">p53 constrains progression to anaplastic thyroid carcinoma in a Braf-mutant mouse model of papillary thyroid cancer.</a> Proceedings of the National Academy of Sciences of the United States of America. 111 (16), 1600-1609 (2014).</li><li>Garassini, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Basic+principles+of+ultrasonic+diagnosis.">Basic principles of ultrasonic diagnosis.</a> GEN. 39 (4), 283-289 (1985).</li><li>Aldrich, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Basic+physics+of+ultrasound+imaging.">Basic physics of ultrasound imaging.</a> Critical Care Medicine. 35, 131-137 (2007).</li><li>Mancini, 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=Morphological+ultrasound+microimaging+of+thyroid+in+living+mice.">Morphological ultrasound microimaging of thyroid in living mice.</a> Endocrinology. 150 (10), 4810-4815 (2009).</li><li>Ying, M., Yung, D. M., Ho, K. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two-dimensional+ultrasound+measurement+of+thyroid+gland+volume:+a+new+equation+with+higher+correlation+with+3-D+ultrasound+measurement.">Two-dimensional ultrasound measurement of thyroid gland volume: a new equation with higher correlation with 3-D ultrasound measurement.</a> Ultrasound in Medicine &amp; Biology. 34 (1), 56-63 (2008).</li></ol>

The authors have no conflicts of interest to declare.

This protocol uses high-resolution ultrasonography to analyze orthotopic ATC tumors in a genetically engineered mouse model. The transgenic model, with a genotype of TPO-cre/ERT2; BrafCA/wt; Trp53&#916;ex2-10/&#916;ex2-10, was developed in our laboratory. The animals overexpress BrafV600E and lack Trp53; injecting the animals intraperitoneally with tamoxifen leads to tumor growth after approximately 1 month10. The tumors grow rapidly and reach a m...

Although anaplastic thyroid carcinoma (ATC) accounts for fewer than 2% of thyroid cancers, it causes more than 50% of thyroid cancer-related deaths annually. The median survival time after diagnosis with ATC is only about 6 months, and no treatments are available that significantly improve survival1,2.
The rarity of ATC has hampered the research studying how the disease begins and aggressively progresses. Genetically engineered mouse models that mimic the disease have recently become available, which provide insights into the disease and its responses to possible treatments3,4,5. Such studies require accurate tumor imaging for measurements and monitoring, which is typically performed using magnetic resonance imaging, computed tomography, or high-resolution ultrasonography6,7. Ultrasonography has been widely used in mouse organs. It has advantages over magnetic resonance imaging and computed tomography since it can be performed in real-time and does not expose the subject to radiation, and the necessary equipment is small enough to be portable8,9. However, studies on continuously monitoring ATC growth using ultrasound are rare; therefore, this work explores the utility of ultrasound in this context.
Here, a protocol for using high-resolution ultrasonography to accurately scan, monitor, and measure tumors in a mouse model of ATC is presented.

<table><tbody><tr><td>Adhesive tape</td><td>Winner</td><td></td><td></td></tr><tr><td>Anesthesia system</td><td>RWDlifescience</td><td></td><td></td></tr><tr><td>&lt;em&gt;Braf&lt;sup&gt;flox/wt&lt;/sup&gt;&lt;/em&gt; mice</td><td>Collaboration with Institute of Life Science, eBond Pharmaceutical Technology Ltd, Chengdu, China</td><td></td><td></td></tr><tr><td>Chamber for anesthesia induction</td><td>RWDlifescience</td><td></td><td></td></tr><tr><td>Cotton swabs</td><td>Winner</td><td></td><td></td></tr><tr><td>Depilatory cream</td><td>Veet</td><td></td><td></td></tr><tr><td>Electric heating blanket</td><td>Petbee</td><td></td><td></td></tr><tr><td>Isoflurane vaporizer</td><td>RWDlifescience</td><td></td><td></td></tr><tr><td>Medical gloves</td><td>Winner</td><td></td><td></td></tr><tr><td>Paper towels</td><td>Breeze</td><td>B914JY</td><td></td></tr><tr><td>TPO-cre/ERT2 mice</td><td>Collaboration with Institute of Life Science, eBond Pharmaceutical Technology Ltd, Chengdu, China</td><td></td><td></td></tr><tr><td>&lt;em&gt;Trp53&lt;sup&gt;flox/wt &lt;/sup&gt;&lt;/em&gt;mice</td><td>Collaboration with Institute of Life Science, eBond Pharmaceutical Technology Ltd, Chengdu, China</td><td></td><td></td></tr><tr><td>Ultrasound gel</td><td>Keppler</td><td>KL-250</td><td></td></tr><tr><td>Ultrasound machine</td><td>VisualSonics</td><td>Vevo 3100</td><td></td></tr></tbody></table>

high-resolution ultrasonography for the analysis of orthotopic atc tumors in a genetically engineered mouse model

Anaplastic thyroid carcinoma (ATC) is associated with a poor prognosis and short median survival time, but no effective treatment improves the outcomes significantly. Genetically engineered murine models that mimic ATC&#39;s progression may help researchers to study treatments for this disease. Crossing three different genotypes of mice, a TPO-cre/ERT2; BrafCA/wt; Trp53&#916;ex2-10/&#916;ex2-10&#160;transgenic ATC model was developed. The ATC murine model was induced by an intraperitoneal injection of tamoxifen with overexpression of BrafV600E and deletion of Trp53, and the tumors were generated within about 1 month. High-resolution ultrasound was applied to investigate the tumor initiation and progression, and the dynamic growth curve was obtained by measuring the tumor sizes. Compared to magnetic resonance imaging (MRI) and computed tomography scanning, ultrasound has advantages in observing the ATC murine model, such as being noninvasive, portable, in real-time, and without radiation exposure. High-resolution ultrasound is suitable for dynamic and multiple measurements. However, ultrasonographic examination of the thyroid in mice requires relevant anatomical knowledge and experience. This article provides a detailed procedure for utilizing high-resolution ultrasound to scan tumors in the transgenic ATC model. Meanwhile, ultrasonic parameter adjustment, ultrasound scanning skills, anesthesia and recovery of the animals, and other elements that need attention during the process are listed.

The average right ATC size at the beginning of the study was 4.867 mm2, and the average left ATC size was 5.189 mm2. On the fourth measurement, the average right ATC size had grown to 11.844 mm2, while the tumor size of the left lobe had grown to 9.280 mm2. The total ATC size increased from 10.057 mm2 to 15.843 mm2. In the later stage of the study, the ATC grew rapidly. In terms of the mouse labeled &#34;P92&#34; (Table 1), the tumor size ...

Watch this Scientific Journal Video about High-Resolution Ultrasonography for the Analysis of Orthotopic ATC Tumors in a Genetically Engineered Mouse Model at JoVE.com

High-Resolution Ultrasonography for the Analysis of Orthotopic ATC Tumors in a Genetically Engineered Mouse Model

The present protocol describes high-frequency ultrasonography for visualizing the entire mouse thyroid gland and monitoring the growth of anaplastic thyroid carcinoma.

Anaplastic thyroid carcinoma (ATC) is associated with a poor prognosis and short median survival time, but no effective treatment improves the outcomes ...

high-resolution-ultrasonography-for-analysis-orthotopic-atc-tumors

Research

JoVE Journal

Cancer Research

1.7K Views.  Sichuan University. Dit protocol helpt gebruikers om echografie met hoge resolutie te gebruiken om tumoren in het muismodel van anaplastisch schildkliercarcinoom te scannen, te controleren en te meten. Echografie is betrouwbaar gebleken bij muizen voor het afbeelden van weefsels die vergelijkbare lichaamslocaties bezetten als menselijke weefsels, waaronder de lever, schildklier en foetus. Schakel om te beginnen het echografiesysteem in en maak een nieuwe map voor het vastleggen van de afbeeldingen en het verzame...

Video: High-Resolution Ultrasonography for the Analysis of Orthotopic ATC Tumors in a Genetically Engineered Mouse Model

Utilizing High Resolution Ultrasound to Monitor Tumor Onset and Growth in Genetically Engineered Pancreatic Cancer Models

The LSL-KrasG12D/+; LSL-Trp53R172H/+; Pdx-1-Cre (KPC) mouse model represents an established and frequently used transgenic model to evaluate novel therapies in pancreatic cancer. Tumor onset is variable in the KPC model between 8 weeks and several months. Therefore, non-invasive imaging tools are required to screen for tumor onset and monitor for response to treatment. To address this issue, different approaches have emerged over the last years. High resolution ultrasound has major advantages such as non-invasiveness, fast session times and a high image resolution without radiation exposure. However, ultrasound in mice is not trivial and sufficient anatomical knowledge and practical skills are required to successfully perform high resolution ultrasound in preclinical pancreatic cancer models. With the following article, a detailed hands-on guide for abdominal ultrasound in murine models with a particular focus on endogenous pancreatic cancer models is presented. Furthermore, a summary of common mistakes and how to avoid them is provided.

This article describes the utilization of high-resolution ultrasound in genetically engineered pancreatic cancer mice. The primary aim is to provide a detailed instruction for detection and evaluation of endogenous pancreatic tumors.

The LSL-KrasG12D/+; LSL-Trp53R172H/+; Pdx-1-Cre (KPC) mouse model represents an established and frequently used transgenic model to evaluate novel ...

An Oncogenic Hepatocyte-Induced Orthotopic Mouse Model of Hepatocellular Cancer Arising in the Setting of Hepatic Inflammation and Fibrosis

The absence of a clinically relevant animal model addressing the typical immune characteristics of hepatocellular cancer (HCC) has significantly impeded elucidation of the underlying mechanisms and development of innovative immunotherapeutic strategies. To develop an ideal animal model recapitulating human HCC, immunocompetent male C57BL/6J mice first receive a carbon tetrachloride (CCl4) injection to induce liver fibrosis, then receive histologically-normal oncogenic hepatocytes from young male SV40 T antigen (TAg)-transgenic mice (MTD2) by intra-splenic (ISPL) inoculation. Androgen generated in recipient male mice at puberty initiates TAg expression under control of a liver-specific promoter. As a result, the transferred hepatocytes become cancer cells and form tumor masses in the setting of liver fibrosis/cirrhosis. This novel model mimics human HCC initiation and progression in the context of liver fibrosis/cirrhosis and reflects the most typical features of human HCC including immune dysfunction.

Here, we describe the development of a clinically relevant murine model of liver cancer recapitulating the typical immune features of hepatocellular cancer (HCC).

The absence of a clinically relevant animal model addressing the typical immune characteristics of hepatocellular cancer (HCC) has significantly impeded ...

Using the BLT Humanized Mouse as a Stem Cell based Gene Therapy Tumor Model

Small animal models such as mice have been extensively used to study human disease and to develop new therapeutic interventions. Despite the wealth of information gained from these studies, the unique characteristics of mouse immunity as well as the species specificity of viral diseases such as human immunodeficiency virus (HIV) infection led to the development of humanized mouse models. The earlier models involved the use of C. B 17 scid/scid mice and the transplantation of human fetal thymus and fetal liver termed thy/liv (SCID-hu) 1, 2 or the adoptive transfer of human peripheral blood leukocytes (SCID-huPBL) 3. Both models were mainly utilized for the study of HIV infection.
One of the main limitations of both of these models was the lack of stable reconstitution of human immune cells in the periphery to make them a more physiologically relevant model to study HIV disease. To this end, the BLT humanized mouse model was developed. BLT stands for bone marrow/liver/thymus. In this model, 6 to 8 week old NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) immunocompromised mice receive the thy/liv implant as in the SCID-hu mouse model only to be followed by a second human hematopoietic stem cell transplant 4. The advantage of this system is the full reconstitution of the human immune system in the periphery. This model has been used to study HIV infection and latency 5-8.
We have generated a modified version of this model in which we use genetically modified human hematopoietic stem cells (hHSC) to construct the thy/liv implant followed by injection of transduced autologous hHSC 7, 9. This approach results in the generation of genetically modified lineages. More importantly, we adapted this system to examine the potential of generating functional cytotoxic T cells (CTL) expressing a melanoma specific T cell receptor. Using this model we were able to assess the functionality of our transgenic CTL utilizing live positron emission tomography (PET) imaging to determine tumor regression (9).
The goal of this protocol is to describe the process of generating these transgenic mice and assessing in vivo efficacy using live PET imaging. As a note, since we use human tissues and lentiviral vectors, our facilities conform to CDC NIH guidelines for Biosafety Level 2 (BSL2) with special precautions (BSL2+). In addition, the NSG mice are severely immunocompromised thus, their housing and maintenance must conform to the highest health standards (<a href="http://jaxmice.jax.org/research/immunology/005557-housing.html" target="_blank">http://jaxmice.jax.org/research/immunology/005557-housing.html</a>).

The generation and characterization of tumor specific T cells using humanized mice is described here. Human thymic tissue and genetically modified human hematopoietic stem cells are transplanted into immunocompromised mice. This results in the reconstitution of an engineered human immune system allowing for in vivo examination of anti-tumor immune responses.

Small animal models such as mice have been extensively used to study human  disease and to develop new therapeutic interventions. Despite the wealth of  ...

Immunology and Infection

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 ...

An Orthotopic Mouse Model of Anaplastic Thyroid Carcinoma

Several types of animal models of human thyroid carcinomas have been established, including subcutaneous xenograft and orthotopic implantation of cancer cells into immunodeficient mice. Subcutaneous xenograft models have been valuable for preclinical screening and evaluation of new therapeutic treatments. There are a number of advantages to using a subcutaneous model; 1) rapid, 2) reproducible, and 3) tumor establishment, growth, and response to therapeutic agents may be monitored by visual inspection. However, substantial evidence has shed light on the short-comings of subcutaneous xenograft models1-3. For instance, medicinal treatments demonstrating curative properties in subcutaneous xenograft models often have no notable impact on the human disease. The microenvironment of the site of xenographic transplantation or injection lies at the heart of this dissimilarity.
Orthotopic tumor xenograft models provide a more biologically relevant context in which to study the disease. The advantages of implanting diseased cells or tissue into their anatomical origin equivalent within a host animal includes a suitable site for tumor-host interactions, development of disease-related metastases and the ability to examine site-specific influence on investigational therapeutic remedies. Therefore, orthotopic xenograft models harbor far more clinical value because they closely reproduce human disease. For these reasons, a number of groups have taken advantage of an orthotopic thyroid cancer model as a research tool4-7.
Here, we describe an approach that establishes an orthotopic model for the study of anaplastic thyroid carcinoma (ATC), which is highly invasive, resists treatment, and is virtually fatal in all diagnosed patients. Cultured ATC cells are prepared as a dissociated cellular suspension in a solution containing a basement membrane matrix. A small volume is slowly injected into the right thyroid gland. Overall appearance and health of the mice are monitored to ensure minimal post-operative complications and to gauge pathological penetrance of the cancer. Mice are sacrificed at 4 weeks, and tissue is collected for histological analysis. Animals may be taken at later time-points to examine more advance progression of the disease. Production of this orthotopic mouse model establishes a platform that accomplishes two objectives: 1) further our understanding of ATC pathology, and 2) screen current and future therapeutic agents for efficacy in combating ATC.

Generation of an orthotopic mouse model of anaplastic thyroid carcinoma is described here. This technique employs surgical placement of human anaplastic thyroid cancer cells into the thyroid of immunodeficient mice, thus creating a more clinically relevant setting to study disease progression as well as screen innovative therapeutic interventions.

Several types of animal models of human thyroid carcinomas have been established, including subcutaneous xenograft and orthotopic implantation of cancer ...

Medicine

Minimally Invasive Establishment of Murine Orthotopic Bladder Xenografts

Orthotopic bladder cancer xenografts are the gold standard to study molecular cellular manipulations and new therapeutic agents&#160;in vivo. Suitable cell lines are inoculated either by intravesical instillation (model of nonmuscle invasive growth) or intramural injection into the bladder wall (model of invasive growth). Both procedures are complex and highly time-consuming. Additionally, the superficial model has its shortcomings due to the lack of cell lines that are tumorigenic following instillation. Intramural injection, on the other hand, is marred by the invasiveness of the procedure and the associated morbidity for the host mouse.
With these shortcomings in mind, we modified previous methods to develop a minimally invasive approach for creating orthotopic bladder cancer xenografts. Using ultrasound guidance we have successfully performed percutaneous inoculation of the bladder cancer cell lines UM-UC1, UM-UC3 and UM-UC13 into 50 athymic nude. We have been able to demonstrate that this approach is time efficient, precise and safe. With this technique, initially a space is created under the bladder mucosa with PBS, and tumor cells are then injected into this space in a second step. Tumor growth is monitored at regular intervals with bioluminescence imaging and ultrasound. The average tumor volumes increased steadily in in all but one of our 50 mice over the study period.
In our institution, this novel approach, which allows bladder cancer xenograft inoculation in a minimally-invasive, rapid and highly precise way, has replaced the traditional model.

The established technique to inoculate primary invasive orthotopic bladder cancer xenografts requires laparotomy and mobilization of the bladder. This procedure inflicts significant morbidity on the mice, is technically challenging and time-consuming. We therefore developed a high-precision, percutaneous approach utilizing ultrasound guidance.

Orthotopic bladder cancer xenografts are the gold standard to study molecular cellular manipulations and new therapeutic agents&#160;in vivo. Suitable ...

Ultrasound Imaging-guided Intracardiac Injection to Develop a Mouse Model of Breast Cancer Brain Metastases Followed by Longitudinal MRI

Breast cancer brain metastasis, occurring in 30% of breast cancer patients at stage IV, is associated with high mortality. The median survival is only 6 months. It is critical to have suitable animal models to mimic the hemodynamic spread of the metastatic cells in the clinical scenario. Here, we are introducing the use of small animal ultrasound imaging to guide an accurate injection of brain tropical breast cancer cells into the left ventricle of athymic nude mice. Longitudinal MRI is used to assessing intracranial initiation and growth of brain metastases. Ultrasound-guided intracardiac injection ensures not only an accurate injection and hereby a higher successful rate but also significantly decreased mortality rate, as compared to our previous manual procedure. In vivo high resolution MRI allows the visualization of hyperintense multifocal lesions, as small as 310 &#181;m in diameter on T2-weighted images at 3 weeks post injection. Follow-up MRI reveals intracranial tumor growth and increased number of metastases that distribute throughout the whole brain.

A breast cancer brain metastasis mouse model is established with ultrasound imaging-guided intracardiac injection of MDA-MB231/Br-GFP cells. Development of multifocal intracranial metastases has been monitored longitudinally using high-resolution 9.4 T MRI.

Breast cancer brain metastasis, occurring in 30% of breast cancer patients at stage IV, is associated with high mortality. The median survival is only 6 ...

Non-Invasive PET/MR Imaging in an Orthotopic Mouse Model of Hepatocellular Carcinoma

Preclinical experimental models of hepatocellular carcinoma (HCC) that recapitulate human disease represent an important tool to study tumorigenesis and evaluate novel therapeutic approaches. Non-invasive whole-body imaging using positron emission tomography (PET) provides critical insights into the in vivo characteristics of tissues at the molecular level in real-time. We present here a protocol for orthotopic HCC xenograft creation with and without hepatic artery ligation (HAL) to induce tumor hypoxia and the assessment of their tumor metabolism in vivo using [18F]Fluoromisonidazole ([18F]FMISO) and [18F]Fluorodeoxyglucose ([18F]FDG) PET/magnetic resonance (MR) imaging. Tumor hypoxia could be readily visualized using the hypoxia marker [18F]FMISO, and it was found that the [18F]FMISO uptake was higher in HCC mice that underwent HAL than in the non-HAL group, whereas [18F]FDG could not distinguish tumor hypoxia between the two groups. HAL tumors also displayed a higher level of hypoxia-inducible factor (HIF)-1&#945; expression in response to hypoxia. Quantification of HAL tumors showed a 2.3-fold increase in [18F]FMISO uptake based on the standardized value uptake (SUV) approach.

Here, we present a protocol to create orthotopic hepatocellular carcinoma xenografts with and without hepatic artery ligation and perform non-invasive positron emission tomography (PET) imaging of tumor hypoxia using [18F]Fluoromisonidazole ([18F]FMISO) and [18F]Fluorodeoxyglucose ([18F]FDG).

Preclinical experimental models of hepatocellular carcinoma (HCC) that recapitulate human disease represent an important tool to study tumorigenesis and ...

Spontaneous Murine Model of Anaplastic Thyroid Cancer

Anaplastic thyroid cancer (ATC) is a rare but lethal malignancy with a dismal prognosis. There is an urgent need for more in-depth research on the carcinogenesis and development of ATC, as well as therapeutic methods, since standard treatments are essentially depleted in ATC patients. However, low prevalence has hampered thorough clinical studies and the collection of tissue samples, so little progress has been achieved in creating effective treatments. We used genetic engineering to create a conditionally inducible ATC murine model (mATC) in a C57BL/6 background. The ATC murine model was genotyped by TPO-cre/ERT2; BrafCA/wt; Trp53ex2-10/ex2-10 and induced by intraperitoneal injection with tamoxifen. With the murine model, we investigated the tumor dynamics (tumor size ranged from 12.4 mm2 to 32.5 mm2 after 4 months of induction), survival (the median survival period was 130 days), and metastasis (lung metastases occurred in 91.6% of mice) curves and pathological features (characterized by Cd8, Foxp3, F4/80, Cd206, Ki67, and Caspase-3 immunohistochemical staining). The results indicated that spontaneous mATC possesses highly similar tumor dynamics and immunological microenvironment to human ATC tumors. In conclusion, with high similarity in pathophysiological features and unified genotypes, the mATC model resolved the shortage of clinical ATC tissue and sample heterogeneity to some extent. Therefore, it would facilitate the mechanism and translational studies of ATC and provide an approach to investigate the treatment potential of small molecular drugs and immunotherapy agents for ATC.

Here, we present a standard pipeline to obtain murine ATC tumors by spontaneous genetically engineered mouse models. Further, we present tumor dynamics and pathological information about the primary and metastasized lesions. This model will help researchers to understand tumorigenesis and facilitate drug discoveries.

Anaplastic thyroid cancer (ATC) is a rare but lethal malignancy with a dismal prognosis. There is an urgent need for more in-depth research on the ...

Liver Transplantation in Mouse and Analyzing Allograft Patency

Successful Orthotopic Liver Transplantation in Mice Utilizing Microcomputed Tomography Angiography

Microcomputed tomography (microCT) angiography is an invaluable resource to researchers. New advances in this technology have allowed for high-quality images to be obtained of micro-vasculature and are high-fidelity tools in the field of organ transplantation. In this model of orthotopic liver transplantation (OLT) in mice, microCT affords the opportunity to evaluate allograft anastomosis in real time and has the added benefit of not having to sacrifice study animals. The choice of contrast, as well as image acquisition settings, create a high-definition image, which gives researchers invaluable information. This allows for evaluation of the technical aspects of the procedure as well as potentially evaluating different therapeutics over an extended duration of time. In this protocol, we detail an OLT model in mice in a stepwise fashion and finally describe a microCT protocol that can give high-quality images, which aid researchers in in-depth analysis of solid organ transplantation. We provide a step-by-step guide for liver transplantation in a mouse, as well as briefly discuss a protocol for evaluating the patency of the graft through microCT angiography.

Author Spotlight: Enhancing Transplantation Research Through MicroCT Angiography in Murine Models 

In this protocol, we discuss the implementation of a model of successful orthotopic liver transplantation (OLT) in mice. Additionally, adjuvants to further analyze allograft patency after successful OLT in a mouse are discussed as well, specifically utilizing microcomputed tomography (microCT) scans.

Microcomputed tomography (microCT) angiography is an invaluable resource to researchers. New advances in this technology have allowed for high-quality ...

High-Resolution Ultrasonography for the Analysis of Orthotopic ATC Tumors in a Genetically Engineered Mouse Model

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