Authors thank Jeffrey Sellers to assist orthotopic pancreatic cancer mouse modeling. This work was supported by Research Initiative Pilot Awards from the Department of Radiology at UAB and NIH grants 2P30CA013148 and P50CA101955.

All procedures were approved by the Institutional Animal Care and Use Committee at the University of Alabama at Birmingham.
1. Orthotopic Pancreatic Tumor Mouse Modeling
<ol>
	<li>Culture standard human pancreatic-cancer cell lines in Dulbecco&#8217;s modified Eagle&#8217;s medium (DMEM) supplemented with 10% fetal bovine serum. Maintain all cultures at 37 &#176;C in humidified atmosphere with 5% CO2.</li>
	<li>Use 8-10 week-old female severe combined immunodeficient&#160;mice. Place animal cages at 12 hr light and 12 hr darkness cycle at RT (21 &#177; 2 &#176;C) and 60% humidity.</li>
	<li>Anesthetize all animals using ventilation with 2% of isoflurane mixed with oxygen (2 L/min) throughout surgery. Confirm the depth of anesthesia by toe pinch reflex. Place animals on a heating pad (37 &#176;C) to maintain the body temperature.&#160;Apply veterinary ophthalmic ointment on eyes to prevent dryness while under anesthesia. &#160;</li>
	<li>Remove the hair in the left upper quadrant of the abdomen of each mouse, and give an analgesic drug (carpofen, 5 mg/kg of body weight subcutaneously) into the area. Apply a betadine solution to the exposed skin. Prepare autoclaved surgical instruments.</li>
	<li>Make a 1 cm incision in the skin and peritoneum using iris straight scissors. Gently remove the pancreas from the abdomen using surgical tweezers.</li>
	<li>Insert 28 G needle of a 0.5 ml insulin syringe into the tail of pancreas and then slowly infuse a solution of 2.5 million human pancreatic cancer cells in 30 &#181;l of DMEM. Confirm that a small bleb is created in the head of pancreas by the solution.</li>
	<li>Gently place the pancreas back into the abdomen using surgical tweezers. Close the peritoneum and the skin in 1 layer with 2 interrupted 5-0 Prolene sutures, and then terminate the anesthesia. Do not return an animal that has undergone surgery to the company of other animals until fully recovered.&#160;Remove sutures at 7~10 days post surgery.</li>
	<li>Give another dose of the analgesic drug (carpofen, 5 mg/kg of body weight subcutaneously) at 24 hr after surgery.</li>
	<li>Check tumor size by palpating the surgery area using two fingers. Tumors typically feel denser and bumpier than the surrounding tissues and organs. Usually it takes ~1 - 2 weeks to start feeling a tumor.</li>
	<li>Monitor animals daily for signs of illness. When animals appear ill (lack normal grooming and avoidance behaviors), we terminated them using cervical dislocation while under anesthesia.</li>
</ol>
2. Magnetic Resonance Imaging
<ol>
	<li>Apply MRI when tumor size is about 5 - 7 mm in diameter at usually 2~4 weeks after cell implantation. Use an MR scanner dedicated to small animal imaging or a clinical MR scanner equipped with a specialized coil for small animal imaging. 
	NOTE: We used a 9.4T small animal MR scanner with a combination of a 1H volume resonator/transmitter and a surface coil receiver (30 mm in diameter)(Bruker BioSpin Corp., Billerica, MA). A surface coil provides better signal-to-noise ratio (SNR)14.</li>
	<li>Prepare a gadolinium-based MRI contrast agent to inject ~0.1 - 0.2 mmol/kg to each animal in ~0.1 - 0.2 ml PBS (phosphate buffered saline). 
	NOTE: We used gadoteridol, and injected 0.2 mmol/kg in 0.15 ml PBS over a period of 15 sec (0.1 ml/sec).</li>
	<li>Prepare a micro-polyethelene tube (length: 7.62 mm, inner diameter: 0.28 mm, outer diameter: 0.64 mm). Insert a 30 G needle (12.7 mm length) into one end of the tube, and a 30 G blunt tip needle (9.5 mm length) into the other end. Connect a 1 ml syringe containing MR contrast agent to the blunt tip needle, and slowly push the syringe to fill up the entire tube with the MR contrast agent.</li>
	<li>Anesthetize animals using ventilation with ~1 - 2% of isoflurane mixed with oxygen (2 L/min) throughout preparation and imaging. Confirm the depth of anesthesia by toe pinch reflex. Apply veterinary ophthalmic ointment on eyes to prevent dryness while under anesthesia. Dilate the tail vein using a heat lamp before needle insertion. Grab the middle of the 30 G needle using Kelly forceps, and insert it into the tail vein. Tape both the tail and tube onto a piece of plastic or cardboard paper (10 mm width x 100 mm length) to keep the tail straight.</li>
	<li>Place the animal in supine position in an animal bed equipped with circulating warm water (or warm air) to regulate body&#160;temperature during imaging. Set the temperature on the bed to 37 &#176;C. Insert a rectal temperature probe to monitor the body temperature during imaging.</li>
	<li>Apply an orthogonally bent plastic board into the abdominal area. Make sure the tumor is located behind the upper end of the board, and then pull down the board slightly (~2 mm) to ensure the tumor is caught by the board. Tape the board to animal bed firmly.</li>
	<li>Tape a respiration pad transducer (SA Instrument, Inc., Stony Brook, NY)&#160;&#160;on the chest area to monitor animal respiration during imaging. Place a surface coil on the top of the tumor region, and tape it to animal bed firmly. Push the animal bed into the MR scanner to place the tumor region at the center of the volume coil (inner diameter: 72 mm).</li>
	<li>Perform matching and tuning for both the receiver and transmitter, followed by shimming.</li>
	<li>Begin with an anatomical MR sequence to locate the tumor. Use a T2-weighted (T2W) turbo spin-echo sequence to obtain axial images with the following acquisition parameters. Repetition time (TR)/echo time (TE) = 3,000/34 msec, 128 x 128 matrix, 30 x 30 mm field of view, number of averages = 1, echo train length = 4, and 20 contiguous 1 mm thick slices in an interlaced mode to cover the entire tumor region (total scanning time: 1.6 min). 
	NOTE: Since orthotopic pancreatic tumors are more difficult to be located than subcutaneous ones, conventional localizer images having lower resolution may not be useful.</li>
	<li>Acquire T1-weighted (T1W) images with various flip angles to retrieve T1 map. For this purpose, use a gradient echo multiflip angle approach with the following parameters: repetition time (TR)/echo time (TE) = 115/3 msec, 128 x 128 matrix,&#160;a 30 x 30 mm field of view, number of averages = 4, ~5 - 7 contiguous 1 mm thick slices in an interlaced mode to cover the tumor region, and seven flip angles of 10, 20, 30, 40, 50, 60, and 70 (total scanning time per flip angle: 1 min). 
	NOTE: However, multiflip angle approach is efficient only when B1 field homogeneity is high. If not, T1 maps can be obtained with multiple TR approach instead15.</li>
	<li>Acquire T1W images before and after gadolinium based MR contrast injection. Use the same acquisition parameters and geometry for T1 mapping but with the fixed flip angle of 30. Use linear encoding to ensure steady state when the center of k-space is obtained, especially when a short TR and a low degree flip angle are used. Acquire 5 baseline images before contrast injection. Then acquire 40 images after contrast injection (total scanning time: 45 min). Use a syringe pump to inject contrast agent at a constant rate (0.01 ml/sec).</li>
	<li>Monitor animal breathing continuously, and adjust isoflurane concentration to keep the respiratory rate to 50 - 100 breaths per min. Monitor animal body temperature throughout imaging.</li>
	<li>After completing DCE-MRI, take off the needle and other probes, and place the animal in an empty cage bedded with paper towels.&#160; Massage softly the lower abdominal area.&#160; The cage should be placed half under a heat lamp to allow the animal to move in and out of the heat gradient as it recovers. &#160;Do not leave an animal unattended until it has regained sufficient consciousness to maintain sternal recumbency.</li>
</ol>
3. Image Processing and Analysis
<ol>
	<li>Segment tumor region in T2W images. In T2W images, the signal intensity in tumor region is brighter than that of surrounding tissues, so the tumor boundary can be manually delineated. 
	NOTE: Semi-automatic segmentation techniques such as global thresholding or active contouring can be used16,17, but uneven background intensity should be corrected especially when a surface coil is used.</li>
	<li>Create T1 and proton density maps. In T1W images acquired with a gradient echo sequence, assuming that echo time (TE) is much less than T2* value, the pixel value is determined by 
	<img alt="Equation 1" fo:content-width="3in" src="/files/ftp_upload/52641/52641eq1.jpg" /> 
	where S0 is proton density, T1 is T1 relaxation time constant, TR is repetition time, and &#952; is a flip angle. Equation (1) can be rewritten to 
	<img alt="Equation 2" fo:content-width="3in" src="/files/ftp_upload/52641/52641eq2.jpg" /> 
	when S(&#952;)/sin&#952; is replaced with Y, and S(&#952;)/tan&#952; is replaced with X. Equation (2) is a linear equation, and its slope and intercept can be used to retrieve T1 and S0 values, respectively.</li>
	<li>Calculate MR contrast concentration in DCE-MR images. When gadolinium based MR contrast agent is injected, T1 relaxation time constant is changed over time. So, equation (1) can be rewritten to 
	<img alt="Equation 3" fo:content-width="3in" src="/files/ftp_upload/52641/52641eq3.jpg" /> 
	T1(t) is related with MR contrast concentration, C(t), as follows, 
	<img alt="Equation 4" fo:content-width="3in" src="/files/ftp_upload/52641/52641eq4.jpg" /> 
	where r1 is longitudinal relaxivity of MR contrast agent. So, by combining equations (3) and (4), MR contrast concentration is determined by 
	<img alt="Equation 5" fo:content-width="3in" src="/files/ftp_upload/52641/52641eq5.jpg" /></li>
	<li>Quantitate the pharmacokinetic parameters of MR contrast agent. Cp(t) presents MR contrast concentration in blood plasma at time t after initiating contrast injection. Cp(t) is called arterial input function (AIF). If AIF is available, the pharmacokinetic parameters of MR contrast agent can be calculated by 
	<img alt="Equation 6" fo:content-width="4in" src="/files/ftp_upload/52641/52641eq6.jpg" /> 
	where Ct(t) is MR contrast concentration in a target tissue, vp is fractional blood plasma volume, ve is fractional extravascular extracellular volume, and Ktrans is volume transfer constant. Flux rate constant, kep, is equal to Ktrans divided by ve. If AIF is not available, then the reference region model can be used instead18,19. The reference region model is based on the flow-limited Kety model20 and uses contrast concentration in a reference region to remove the need for AIF as follows, 
	<img alt="Equation 7" fo:content-width="5in" src="/files/ftp_upload/52641/52641eq7.jpg" /> 
	where Ct,ROI(t), Ktrans,ROI, and ve,ROI are contrast concentration, volume transfer constant, and fractional extravascular-extracellular volume, respectively, in the region of interest (ROI), while Ct,RR(t), Ktrans,RR, and ve,RR are those in the reference region. Paravertebral muscle is often selected as the reference region, and ve,RR in murine paravertebral muscle is assumed to be constant at 0.08 21. We used the reference region model.</li>
</ol>

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Authors do not have any conflicts of interest to declare.

We have introduced the detailed methods of orthotopic pancreatic tumor modeling using immunodeficient mice, DCE-MRI of abdominal tumors in mice, and quantification of its kinetic parameters. In orthotopic pancreatic tumor modeling, care must be taken when inserting a needle into the tail of pancreas. If successful, cells will be transferred to the head of pancreas creating a small bleb. When applying an orthogonally bent plastic board, it is critical to confirm that the tumor is located below the upper end of the board. ...

The overall goal of this method is to apply dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) for orthotopic pancreatic tumor xenografts in mice. DCE-MRI is a non-invasive method to assess microvasculature in a target tissue by monitoring the change of MR contrast over a certain period of time after injection. DCE-MRI has been utilized to diagnose malignant tumors and to assess tumor response to various therapies1-4. Quantitative DCE-MRI has presented high reproducibility5. To quantitate pharmacokinetic parameters of an MR contrast agent in a target tissue, all DCE-MR images acquired at different time points and T1 map obtained before contrast injection must be coregistered6. However, due to respiratory and peristaltic motions in the abdominal area, quantitative DCE-MRI has had limited application for gastrointestinal tumors.
Orthotopic pancreatic tumor models have been utilized to assess pancreatic-tumor response following biological therapies and chemotherapies7,8. Orthotopic tumor models are considered superior to conventional subcutaneous models, since the microenvironment in the original tumor site is reflected and thereby human tumor response to therapy can be more accurately predicted. However, the mouse pancreas is located in the left upper quadrant of the abdomen, so quantitative DCE-MRI of orthotopic pancreatic tumor xenografts in mice has not been readily implemented.
We have established a protocol of DCE-MRI of abdominal tumors in mice by fixing the tumors using an orthogonally bent plastic board to prevent motion transfer from the chest region9. The pressure applied by this board was localized on the abdominal area, and has not resulted in respiratory difficulty. An automated image coregistration technique has been validated for DCE-MRI of abdominal organs in a free-breathing mode, but it performs effectively only when the target regions move slowly and regularly10. Respiratory rate of animals is variable during imaging, so physical restraint in the abdominal area will be necessary to retrieve reliable pharmacokinetic parameters in orthotopic pancreatic tumor mouse models. We have successfully quantitated the pharmacokinetic parameters of an MR contrast agent in orthotopic pancreatic tumor xenografts using the orthogonally bent plastic board in DCE-MRI11-13. Here we present the detailed procedure of orthotopic pancreatic tumor modeling, DCE-MRI of the tumor xenografts in mice, and quantification of pharmacokinetic parameters.

<table border="0" cellpadding="0" cellspacing="0" width="1275">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:245px;">Name of Material/ Equipment</td>
			<td style="width:199px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:712px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">DMEM</td>
			<td>Invitrogen</td>
			<td>11965-118</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Fetal bovine serum</td>
			<td>Harlan Laboratories</td>
			<td>BT-9501</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Betadine</td>
			<td style="width:199px;">Purdue products</td>
			<td style="width:119px;">67618-153-01</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">5-0 Prolene sutures</td>
			<td style="width:199px;">Ethicon</td>
			<td style="width:119px;">8720H</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">9.4T MR scanner</td>
			<td>Bruker Biospin Corporation</td>
			<td style="width:119px;">BioSpec 94/20 USR</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Gadoteridol</td>
			<td>Bracco Diagnostics Inc</td>
			<td style="width:119px;">NDC 0270-1111-03</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Micro-polyethelene tube</td>
			<td style="width:199px;">Strategic Applications, Inc</td>
			<td style="width:119px;">#PE-10-25</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">30G blunt tip needle</td>
			<td style="width:199px;">Strategic Applications, Inc</td>
			<td style="width:119px;">89134-194</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Monitoring and gating system</td>
			<td style="width:199px;">SA instruments, Inc</td>
			<td style="width:119px;">Model 1030</td>
			<td>This is an MR compatiable system to measure resiratory rating and body temperature of small animals at the same time.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Syringe pump</td>
			<td>New Era Pump Systems, Inc.</td>
			<td>NE-1600</td>
			<td></td>
		</tr>
	</tbody>
</table>

dynamic contrast enhanced magnetic resonance imaging of an orthotopic pancreatic cancer mouse model

Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) has been limitedly used for orthotopic pancreatic tumor xenografts due to severe respiratory motion artifact in the abdominal area. Orthotopic tumor models offer advantages over subcutaneous ones, because those can reflect the primary tumor microenvironment affecting blood supply, neovascularization, and tumor cell invasion. We have recently established a protocol of DCE-MRI of orthotopic pancreatic tumor xenografts in mouse models by securing tumors with an orthogonally bent plastic board to prevent motion transfer from the chest region during imaging. The pressure by this board was localized on the abdominal area, and has not resulted in respiratory difficulty of the animals. This article demonstrates the detailed procedure of orthotopic pancreatic tumor modeling using small animals and DCE-MRI of the tumor xenografts. Quantification method of pharmacokinetic parameters in DCE-MRI is also introduced. The procedure described in this article will assist investigators to apply DCE-MRI for orthotopic gastrointestinal cancer mouse models.

Human pancreatic tumor cells grow successfully in mouse pancreas creating a solid tumor. Figure 1 shows photographs of (A) a normal pancreas where tumor cell solution is injected, and (B) a representative mouse bearing an orthotopic pancreatic tumor xenograft (MIA PaCa-2). Tumor is located in the left upper quadrant of abdomen, next to the spleen. It usually takes 2 - 4 weeks for the tumors to grow up to 5 - 7 mm in diameter after cell implantation.
Motion of orthotopic pancre...

Watch this Scientific Journal Video about Dynamic Contrast Enhanced Magnetic Resonance Imaging of an Orthotopic Pancreatic Cancer Mouse Model at JoVE.com

Dynamic Contrast Enhanced Magnetic Resonance Imaging of an Orthotopic Pancreatic Cancer Mouse Model

The goal of this protocol is to apply dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) for orthotopic pancreatic tumor xenografts in mice. DCE-MRI is a non-invasive method to analyze microvasculature in a target tissue, and useful to assess vascular response in a tumor following a novel therapy.

Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) has been limitedly used for orthotopic pancreatic tumor xenografts due to severe ...

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15.0K Views.  University of Alabama at Birmingham. The goal of this protocol is to apply dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) for orthotopic pancreatic tumor xenografts in mice. DCE-MRI is a non-invasive method to analyze microvasculature in a target tissue, and useful to assess vascular response in a tumor following a novel therapy. 

Video: Dynamic Contrast Enhanced Magnetic Resonance Imaging of an Orthotopic Pancreatic Cancer Mouse Model

Combination Radiotherapy in an Orthotopic Mouse Brain Tumor Model

Glioblastoma multiforme (GBM) are the most common and aggressive adult primary brain tumors1. In recent years there has been substantial progress in the understanding of the mechanics of tumor invasion, and direct intracerebral inoculation of tumor provides the opportunity of observing the invasive process in a physiologically appropriate environment2. As far as human brain tumors are concerned, the orthotopic models currently available are established either by stereotaxic injection of cell suspensions or implantation of a solid piece of tumor through a complicated craniotomy procedure3. In our technique we harvest cells from tissue culture to create a cell suspension used to implant directly into the brain. The duration of the surgery is approximately 30 minutes, and as the mouse needs to be in a constant surgical plane, an injectable anesthetic is used. The mouse is placed in a stereotaxic jig made by Stoetling (figure 1). After the surgical area is cleaned and prepared, an incision is made; and the bregma is located to determine the location of the craniotomy. The location of the craniotomy is 2 mm to the right and 1 mm rostral to the bregma. The depth is 3 mm from the surface of the skull, and cells are injected at a rate of 2 &mu;l every 2 minutes. The skin is sutured with 5-0 PDS, and the mouse is allowed to wake up on a heating pad. From our experience, depending on the cell line, treatment can take place from 7-10 days after surgery. Drug delivery is dependent on the drug composition. For radiation treatment the mice are anesthetized, and put into a custom made jig. Lead covers the mouse's body and exposes only the brain of the mouse. The study of tumorigenesis and the evaluation of new therapies for GBM require accurate and reproducible brain tumor animal models. Thus we use this orthotopic brain model to study the interaction of the microenvironment of the brain and the tumor, to test the effectiveness of different therapeutic agents with and without radiation.

The purpose of this article is to describe the use of an orthotopic glioblastoma model for chemoradiation studies. This article will go though cell processing, implanting, and radiotherapy of the mouse using an intracranial model.

Glioblastoma multiforme (GBM) are the most common and aggressive adult primary brain tumors1. In recent years there has been substantial progress in the ...

Multi-modal Imaging of Angiogenesis in a Nude Rat Model of Breast Cancer Bone Metastasis Using Magnetic Resonance Imaging, Volumetric Computed Tomography and Ultrasound

Angiogenesis is an essential feature of cancer growth and metastasis formation. In bone metastasis, angiogenic factors are pivotal for tumor cell proliferation in the bone marrow cavity as well as for interaction of tumor and bone cells resulting in local bone destruction. Our aim was to develop a model of experimental bone metastasis that allows in vivo assessment of angiogenesis in skeletal lesions using non-invasive imaging techniques.
For this purpose, we injected 105 MDA-MB-231 human breast cancer cells into the superficial epigastric artery, which precludes the growth of metastases in body areas other than the respective hind leg1. Following 25-30 days after tumor cell inoculation, site-specific bone metastases develop, restricted to the distal femur, proximal tibia and proximal fibula1. Morphological and functional aspects of angiogenesis can be investigated longitudinally in bone metastases using magnetic resonance imaging (MRI), volumetric computed tomography (VCT) and ultrasound (US).
MRI displays morphologic information on the soft tissue part of bone metastases that is initially confined to the bone marrow cavity and subsequently exceeds cortical bone while progressing. Using dynamic contrast-enhanced MRI (DCE-MRI) functional data including regional blood volume, perfusion and vessel permeability can be obtained and quantified2-4. Bone destruction is captured in high resolution using morphological VCT imaging. Complementary to MRI findings, osteolytic lesions can be located adjacent to sites of intramedullary tumor growth. After contrast agent application, VCT angiography reveals the macrovessel architecture in bone metastases in high resolution, and DCE-VCT enables insight in the microcirculation of these lesions5,6. US is applicable to assess morphological and functional features from skeletal lesions due to local osteolysis of cortical bone. Using B-mode and Doppler techniques, structure and perfusion of the soft tissue metastases can be evaluated, respectively. DCE-US allows for real-time imaging of vascularization in bone metastases after injection of microbubbles7.
In conclusion, in a model of site-specific breast cancer bone metastases multi-modal imaging techniques including MRI, VCT and US offer complementary information on morphology and functional parameters of angiogenesis in these skeletal lesions.

In the pathogenesis of bone metastasis, angiogenesis is a crucial process and therefore represents a target for imaging and therapy. Here, we present a rat model of site-specific breast cancer bone metastasis and describe strategies to non-invasively image angiogenesis in vivo using magnetic resonance imaging, volumetric computed tomography and ultrasound.

Angiogenesis is an essential feature of cancer growth and metastasis formation. In bone metastasis, angiogenic factors are pivotal for tumor cell ...

An Orthotopic Bladder Tumor Model and the Evaluation of Intravesical saRNA Treatment

We present a novel method for treating bladder cancer with intravesically delivered small activating RNA (saRNA) in an orthotopic xenograft mouse bladder tumor model. The mouse model is established by urethral catheterization under inhaled general anesthetic. Chemical burn is then introduced to the bladder mucosa using intravesical silver nitrate solution to disrupt the bladder glycosaminoglycan layer and allows cells to attach. Following several washes with sterile water, human bladder cancer KU-7-luc2-GFP cells are instilled through the catheter into the bladder to dwell for 2 hours. Subsequent growth of bladder tumors is confirmed and monitored by in vivo bladder ultrasound and bioluminescent imaging. The tumors are then treated intravesically with saRNA formulated in lipid nanoparticles (LNPs). Tumor growth is monitored with ultrasound and bioluminescence. All steps of this procedure are demonstrated in the accompanying video.

Establishing an orthotopic bladder tumor model to evaluate antitumor effects of intravesically delivered saRNA and monitoring tumor growth by ultrasound and bioluminescent imaging.

We present a novel method for treating bladder cancer with intravesically delivered small activating RNA (saRNA) in an orthotopic xenograft mouse bladder ...

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 ...

An Orthotopic Bladder Cancer Model for Gene Delivery Studies

Bladder cancer is the second most common cancer of the urogenital tract and novel therapeutic approaches that can reduce recurrence and progression are needed. The tumor microenvironment can significantly influence tumor development and therapy response. It is therefore often desirable to grow tumor cells in the organ from which they originated. This protocol describes an orthotopic model of bladder cancer, in which MB49 murine bladder carcinoma cells are instilled into the bladder via catheterization. Successful tumor cell implantation in this model requires disruption of the protective glycosaminoglycan layer, which can be accomplished by physical or chemical means. In our protocol the bladder is treated with trypsin prior to cell instillation. Catheterization of the bladder can also be used to deliver therapeutics once the tumors are established. This protocol describes the delivery of an adenoviral construct that expresses a luciferase reporter gene. While our protocol has been optimized for short-term studies and focuses on gene delivery, the methodology of mouse bladder catheterization has broad applications.

Implantation of cancer cells into the organ of origin can serve as a useful preclinical model to evaluate novel therapies. MB49 bladder carcinoma cells can be grown within the bladder following intravesical instillation. This protocol demonstrates catheterization of the mouse bladder for the purpose of tumor implantation and adenoviral delivery.

Bladder cancer is the second most common cancer of the urogenital tract and novel therapeutic approaches that can reduce recurrence and progression are ...

Bioluminescent Orthotopic Model of Pancreatic Cancer Progression

Pancreatic cancer has an extremely poor five-year survival rate of 4-6%. New therapeutic options are critically needed and depend on improved understanding of pancreatic cancer biology. To better understand the interaction of cancer cells with the pancreatic microenvironment, we demonstrate an orthotopic model of pancreatic cancer that permits non-invasive monitoring of cancer progression. Luciferase-tagged pancreatic cancer cells are resuspended in Matrigel and delivered into the pancreatic tail during laparotomy. Matrigel solidifies at body temperature to prevent leakage of cancer cells during injection. Primary tumor growth and metastasis to distant organs are monitored following injection of the luciferase substrate luciferin, using in vivo imaging of bioluminescence emission from the cancer cells. In vivo imaging also may be used to track primary tumor recurrence after resection. This orthotopic model is suited to both syngeneic and xenograft models and may be used in pre-clinical trials to investigate the impact of novel anti-cancer therapeutics on the growth of the primary pancreatic tumor and metastasis.

Improved understanding of pancreatic cancer biology is critically needed to enable the development of better therapeutic options to treat pancreatic cancer. To address this need, we demonstrate an orthotopic model of pancreatic cancer that permits non-invasive monitoring of cancer progression using in vivo bioluminescence imaging.

Pancreatic cancer has an extremely poor five-year survival rate of 4-6%.  New therapeutic options are critically needed and depend on improved ...

An Orthotopic Murine Model of Human Prostate Cancer Metastasis

Our laboratory has developed a novel orthotopic implantation model of human prostate cancer (PCa). As PCa death is not due to the primary tumor, but rather the formation of distinct metastasis, the ability to effectively model this progression pre-clinically is of high value. In this model, cells are directly implanted into the ventral lobe of the prostate in Balb/c athymic mice, and allowed to progress for 4-6 weeks. At experiment termination, several distinct endpoints can be measured, such as size and molecular characterization of the primary tumor, the presence and quantification of circulating tumor cells in the blood and bone marrow, and formation of metastasis to the lung. In addition to a variety of endpoints, this model provides a picture of a cells ability to invade and escape the primary organ, enter and survive in the circulatory system, and implant and grow in a secondary site. This model has been used effectively to measure metastatic response to both changes in protein expression as well as to response to small molecule therapeutics, in a short turnaround time.

This orthotopic model of human prostate cancer allows for quantification of tumor size, circulating tumor cells, and formation of distinct metastasis to the lung. As cells must escape the primary organ, enter the blood stream, and implant into a secondary site, this model effectively recapitulates the scenario in humans.

Our laboratory has developed a novel orthotopic implantation model of  human prostate cancer (PCa). As PCa death is not due to the primary tumor, but  ...

An Orthotopic Glioblastoma Mouse Model Maintaining Brain Parenchymal Physical Constraints and Suitable for Intravital Two-photon Microscopy

Glioblastoma multiforme (GBM) is the most aggressive form of brain tumors with no curative treatments available to date.
Murine models of this pathology rely on the injection of a suspension of glioma cells into the brain parenchyma following incision of the dura-mater. Whereas the cells have to be injected superficially to be accessible to intravital two-photon microscopy, superficial injections fail to recapitulate the physiopathological conditions. Indeed, escaping through the injection tract most tumor cells reach the extra-dural space where they expand abnormally fast in absence of mechanical constraints from the parenchyma.
Our improvements consist not only in focally implanting a glioma spheroid rather than injecting a suspension of glioma cells in the superficial layers of the cerebral cortex but also in clogging the injection site by a cross-linked dextran gel hemi-bead that is glued to the surrounding parenchyma and sealed to dura-mater with cyanoacrylate. Altogether these measures enforce the physiological expansion and infiltration of the tumor cells inside the brain parenchyma. Craniotomy was finally closed with a glass window cemented to the skull to allow chronic imaging over weeks in absence of scar tissue development.
Taking advantage of fluorescent transgenic animals grafted with fluorescent tumor cells we have shown that the dynamics of interactions occurring between glioma cells, neurons (e.g. Thy1-CFP mice) and vasculature (highlighted by an intravenous injection of a fluorescent dye) can be visualized by intravital two-photon microscopy during the progression of the disease.
The possibility to image a tumor at microscopic resolution in a minimally compromised cerebral environment represents an improvement of current GBM animal models which should benefit the field of neuro-oncology and drug testing.

We have established a cortical orthotopic glioblastoma model in mice for intravital two-photon microscopy that recapitulates the biophysical constraints normally at play during the growth of the tumor. A chronic glass window replacing the skull above the tumor enables the follow-up of the tumor progression over time by two-photon microscopy.

Glioblastoma multiforme (GBM) is the most aggressive form of brain tumors with no curative treatments available to date.
Murine models of this pathology ...

Tracking the Mammary Architectural Features and Detecting Breast Cancer with Magnetic Resonance Diffusion Tensor Imaging

Breast cancer is the most common cause of cancer among women worldwide. Early detection of breast cancer has a critical role in improving the quality of life and survival of breast cancer patients. In this paper a new approach for the detection of breast cancer is described, based on tracking the mammary architectural elements using diffusion tensor imaging (DTI). 
The paper focuses on the scanning protocols and image processing algorithms and software that were designed to fit the diffusion properties of the mammary fibroglandular tissue and its changes during malignant transformation. The final output yields pixel by pixel vector maps that track the architecture of the entire mammary ductal glandular trees and parametric maps of the diffusion tensor coefficients and anisotropy indices. 
The efficiency of the method to detect breast cancer was tested by scanning women volunteers including 68 patients with breast cancer confirmed by histopathology findings. Regions with cancer cells exhibited a marked reduction in the diffusion coefficients and in the maximal anisotropy index as compared to the normal breast tissue, providing an intrinsic contrast for delineating the boundaries of malignant growth. Overall, the sensitivity of the DTI parameters to detect breast cancer was found to be high, particularly in dense breasts, and comparable to the current standard breast MRI method that requires injection of a contrast agent. Thus, this method offers a completely non-invasive, safe and sensitive tool for breast cancer detection.

We describe how to obtain parametric and vector maps of the diffusion tensor of the breast using magnetic resonance imaging. The protocol and final output following imaging processing are tailored for tracking breast architectural features and detecting breast malignancy.

Breast cancer is the most common cause of cancer among women worldwide. Early detection of breast cancer has a critical role in improving the quality of ...

Simultaneous PET/MRI Imaging During Mouse Cerebral Hypoxia-ischemia

Dynamic changes in tissue water diffusion and glucose metabolism occur during and after hypoxia in cerebral hypoxia-ischemia reflecting a bioenergetics disturbance in affected cells. Diffusion weighted magnetic resonance imaging (MRI) identifies regions that are damaged, potentially irreversibly, by hypoxia-ischemia. Alterations in glucose utilization in the affected tissue may be detectable by positron emission tomography (PET) imaging of 2-deoxy-2-(18F)fluoro-&#7429;-glucose ([18F]FDG) uptake. Due to the rapid and variable nature of injury in this animal model, acquisition of both modes of data must be performed simultaneously in order to meaningfully correlate PET and MRI data. In addition, inter-animal variability in the hypoxic-ischemic injury due to vascular differences limits the ability to analyze multi-modal data and observe changes to a group-wise approach if data is not acquired simultaneously in individual subjects. The method presented here allows one to acquire both diffusion-weighted MRI and [18F]FDG uptake data in the same animal before, during, and after the hypoxic challenge in order to interrogate immediate physiological changes.

The method presented here uses simultaneous positron emission tomography and magnetic resonance imaging. In the cerebral hypoxia-ischemia model, dynamic changes in diffusion and glucose metabolism occur during and after injury. The evolving and irreproducible damage in this model necessitates simultaneous acquisition if meaningful multi-modal imaging data are to be acquired.

Dynamic changes in tissue water diffusion and glucose metabolism occur during and after hypoxia in cerebral hypoxia-ischemia reflecting a bioenergetics ...