The authors acknowledge the technical services provided by the molecular cytology facility and the animal facility of Memorial Sloan Kettering Cancer Center. This work was supported by NIH grants CA157686 (to R.J. Wong) and P30 CA008748 (Memorial Sloan Kettering Cancer Center support grant).

All of the procedures with animal subjects were approved by the Institutional Animal Care and Use Committee at Memorial Sloan Kettering Cancer Center.
1. Preparation of the Cancer Cells
<ol>
	<li>Harvest sub-confluent Panc02-H7 cells with 0.25% trypsin for 5 min at 37 &#176;C. Collect the cells in a 15 mL centrifuge tube. 
	NOTE: The cells are grown in T-225 flask, which contains about 12 x 106 cells per flask at 80% confluency and 4 mL trypsin/ flask is used.</li>
	<li>Centrifuge the cells at x 900 g at 4&#176;C for 5 min. Wash the cells by resuspending the cell pellet in 1 mL of PBS (by pipetting up and down twice), and transfer the suspension to a 1.5 mL microcentrifuge tube on ice.</li>
	<li>Centrifuge the cells again at x 900 g at 4&#176;C for 5 min, and discard the supernatant without disturbing the pellet. Keep the pelleted cells on ice until injection.</li>
</ol>
2. Preparation of the Mice and Surgery
Note: 8-week-old, male and female C57BL/6J mice are used in this study. The surgery conditions follows the IACUC rules of our institution. The instruments are sterilized, the surgical working surface is disinfected, the animal is disinfected and the surgeon wears sterile gloves.
<ol>
	<li>On the day before the surgery, anesthetize the mouse using 2% isoflurane and then&#160;remove the fur along the length of femur on the dorsal side with either a thin razor or a chemical hair removal agent.</li>
	<li>On the day of the surgery, anesthetize the mice using 2% isofluorane in an induction chamber. Confirm the anesthetization by a toe pinch stimulus and a lack of response.</li>
	<li>Apply vet ointment on eyes to prevent dryness under anesthesia.</li>
	<li>Place the anesthetized mouse on its ventral side, and gently secure each limb with hypoallergenic tape to create mild tension in the limb to be injected.&#160;Anesthesia is maintained using isoflurane delivered via a precision vaporizer and nose cone.</li>
	<li>Clean the injection site with Betadine, then again with 70% alcohol. Repeat this process two more times. Make sure that no loose hair remains on the surgical field.</li>
	<li>Make a 1 cm incision with small scissors about 2 mm below and parallel to the femur. Retract the skin with forceps laterally to expose the muscles underneath.</li>
	<li>The sciatic nerve runs deep to the gluteus maximus and biceps femoris muscles. Separate these two muscles along a fascial plane with small scissors and expose the sciatic nerve underneath. Free the nerve from the surrounding muscles using blunt dissection.</li>
	<li>Draw 3 &#956;L of cancer cells (about 50,000 cells) from the pellet into a 10 &#956;L syringe. 
	NOTE: Alternatively, draw 3 &#956;L of PBS as a control.</li>
	<li>Place a small metal spatula underneath the nerve at the point of injection for support. Under visualization with a dissecting microscope, insert the needle into the nerve against the metal base, keeping the needle as parallel to the nerve as possible upon insertion. Be careful as not to puncture through the back of the nerve. Minimize the handling of nerve as much as possible throughout this process.</li>
	<li>Slowly inject into the nerve over 5 s. A formation of a bulb in the injection area indicates a good injection. Then leave the needle in place for 3 s before removing the needle gently. Keeping the needle in place for 3 s minimizes backflow of the cells out of the nerve. 
	NOTE: Injection can be performed toward the distal nerve or the spinal cord. It is important to remain consistent within a set of experiments. If the cells spill outside, the animal should not be included in the analysis of the experiment. With experience, these events are very rare.</li>
	<li>Return the nerve to its original position. Cover the nerve with the overlying muscles. Treat the mice with proper analgesia, and then close the skin with 5-0 Nylon sutures.</li>
	<li>Place the mouse alone in a clean cage for observation during recovery, until it fully awakens from anesthesia. 
	NOTE: It takes 5-15 min for the animal to regain full consciousness. The animal is not left unattended until it has regained sufficient consciousness to maintain sternal recumbency. The animal is not returned to the company of other animals until fully recovered. Thereafter, evaluate recovery at least once every 24 h for 72 h.</li>
</ol>
3. Sciatic Nerve Extraction
<ol>
	<li>On postop day #7, euthanize the mice with CO2. Place the mouse on its ventral side, and stabilize the distal limbs using pins.</li>
	<li>Remove the skin on the dorsal side of the injected limb and torso.</li>
	<li>Using blunt dissection, expose the sciatic nerve deep to the muscles.</li>
	<li>The nerve courses between the ilium and the sacrum. To have access to the nerve at the spinal cord region, separate the two bones. First insert closed scissors in the narrow area where the sciatic nerve is located and then open the scissors while holding the mouse. Be delicate and maintain the integrity of the sciatic nerve during the dissection.</li>
	<li>Carefully dissect the sciatic nerve distally to the end of the femur, and proximally to the spinal cord.</li>
	<li>NOTE: Invaded nerves are extremely fragile and prone to breaking under tension or forceful handling.</li>
	<li>Harvest the nerve by first cutting its distal end. Carefully lift the nerve while freeing it from adjacent tissue. Cut the nerve at the proximal end, as close as possible to its exit from the spinal column.</li>
	<li>Record then gross length of invasion using a Vernier caliper. This macroscopic estimation is only indicative.</li>
</ol>
4. Nerve Processing and Quantification
<ol>
	<li>Embed the dissected nerve in OCT compound. Make sure to place nerves longitudinally and as flat on the bottom of the mold as possible.</li>
	<li>Indicate on the cassette the proximal and distal side of the nerve by marking the letter P and D.</li>
	<li>Place embedded nerves on top of dry ice, if they are not sectioned immediately. Sample could be preserved at -80 &#176;C for several weeks.</li>
	<li>Section samples using a Cryostat microtome at 5 &#956;m thickness and place sections on glass slides. If possible, fit 2 nerve sections per slide. Indicate proximal side of the nerve.</li>
	<li>Stain slides using H&#38;E staining12.</li>
	<li>Digitally scan stained nerve sections with a slide-scanner that provides high-resolution digital data.</li>
	<li>Using imaging software, quantify the length of invasion by clicking the measure distance button, area of invasion, or other desired parameters. For a good estimation of the length of invasion, use multiple sections (2 to 4) of the same nerve.</li>
</ol>

<ol>
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J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+Schwann+cells+facilitate+cancer+progression+in+nerves.">How Schwann cells facilitate cancer progression in nerves.</a> Cell Mol Life Sci. 341 (177-186), 1236361-1236416 (2017).</li><li>Abiatari, I., 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=Consensus+transcriptome+signature+of+perineural+invasion+in+pancreatic+carcinoma.">Consensus transcriptome signature of perineural invasion in pancreatic carcinoma.</a> Mol Cancer Ther. 8 (6), 1494-1504 (2009).</li><li>Ayala, G. 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The authors have nothing to disclose.

In this protocol we describe an in vivo murine model of perineural invasion that allows for the quantification of sciatic nerve invasion by pancreatic cancer cells. This model enables the study of molecular mechanisms of nerve invasion. Successful experiments using this technique require a careful approach to three critical steps in the process: 1) the injection of cancer cells (steps 2.7, 2.8), 2) the extraction of invaded nerves (step 3.4), and 3) processing of harvested nerves (step 4.1).
<p class="jove_c...

Nerves form a specific tumor microenvironment that stimulates cancer growth and migration1,2,3. Perineural invasion (PNI) is the process through which cancer cells invade in and around the nerves. It may be considered as a unique route of metastasis since cancer invasion extends away from the sites of origin along nerves. PNI is found in several cancer types including pancreatic, prostate, head &#38; neck, salivary, cervical, and colorectal cancers with an incidence ranging from 22% to 100%1,2. PNI is associated with pain and correlates with poor prognosis and worse survival rates1,2.
Developing models of perineural invasion is essential to elucidate the cellular and molecular mechanisms of this process, and to test candidate therapeutic agents to decrease PNI. In vitro methods of studying interactions between cancers and nerves include the co-culture of cancer cells with nerve explants4, with dorsal root ganglions5,6,7, or with specific cells from the nerve microenvironment such as Schwann cells7. In vivo approaches, however, are more physiologically relevant, include the use of cancer mouse models in which cancer has been induced or transplanted and have the advantage of accounting for the entire nerve microenvironment. In orthotopic models of pancreatic or prostate cancer, PNI has been reported8,9,10 and the incidence of PNI may be recorded, but because of the small size of the nerves in those organs, it is difficult to see the entire nerve and therefore to quantify the extent of PNI. The model we describe here is an in vivo model of PNI in which cancer cells are injected into the sciatic nerve of mice through a simple surgical procedure11. The heterotopic transplant invades within the nerve toward the spinal cord. The length of the nerve invasion from the site of injection to the spinal cord may be measured, as well as the volume of the cancer within the nerve. Importantly, the invaded nerve can also be collected for a variety of assays including microscopic, and molecular analyses. A variety of cancer cells can be tested, and the host mice that have been genetically modified or treated with specific compounds may be used as well. This powerful assay allows for the cancer cells and the host microenvironment to be modified for investigation into the mechanisms of PNI.

<table border="0" cellpadding="0" cellspacing="0" style="width:973px;" width="973">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="40">
			<td height="40" style="height:40px;width:340px;">Mouse</td>
			<td style="width:123px;"></td>
			<td style="width:344px;"></td>
			<td style="width:167px;">Number and age variable depending on experimental needs</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Cell culture media (PBS, Trypsin, and DMEM+10% FBS)</td>
			<td>Any</td>
			<td></td>
			<td>Steps 1.1, 1.2, 1.3.</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Conical centrifuge tube, 50 mL</td>
			<td>Falcon</td>
			<td>352098</td>
			<td>Step 1.1</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Microcentrifuge tube 1.5 mL</td>
			<td>Axygen</td>
			<td>MCT-150-C-S</td>
			<td>Step 1.2</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Electric razor</td>
			<td>WAHL</td>
			<td>9962</td>
			<td>Step 2.1. Can be substituted with commercial hair removal agent</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Isoflurane, 250 mL</td>
			<td>Baxter</td>
			<td>1001936060</td>
			<td>Step 2.2</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Hypoallergenic surgical tape</td>
			<td>3M Blenderm</td>
			<td>70200419342</td>
			<td>Step 2.3</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Betadine Swapsticks</td>
			<td>PDI</td>
			<td>SKU 41350</td>
			<td>Step 2.4</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Webcol Alcohol Preps</td>
			<td>Covidien</td>
			<td>5110</td>
			<td>Step 2.4</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Sterile surgical tools (scissors and forceps)</td>
			<td></td>
			<td></td>
			<td>Steps 2.4, 2.5, 3.3, 3.4, 3.5</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">10 &#956;L Hamilton syringe</td>
			<td>Hamilton</td>
			<td>80308</td>
			<td>Steps 2.7, 2.8</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Steel Micro spatula</td>
			<td>Fisher Scientific</td>
			<td>S50823</td>
			<td>Step 2.7</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Dissecting microscope</td>
			<td></td>
			<td></td>
			<td>Step 2.7</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Bupivacine, 1 g</td>
			<td>Enzo Life Sciences</td>
			<td>BML-NA139-0001</td>
			<td>Step 2.9. Reconstitute to 0.5%</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">5-0 Nylon suture</td>
			<td>Ethicon</td>
			<td>698H</td>
			<td>Step 2.9</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Tissue-Tek O.C.T. Compound</td>
			<td>VWR</td>
			<td>25608-930</td>
			<td>Step 4.1</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Tissue-Tek Cryomold Molds</td>
			<td>VWR</td>
			<td>25608-916</td>
			<td>Step 4.1</td>
		</tr>
	</tbody>
</table>

an in vivo murine sciatic nerve model of perineural invasion

Cancer cells invade nerves through a process termed perineural invasion (PNI), in which cancer cells proliferate and migrate in the nerve microenvironment. This type of invasion is exhibited by a variety of cancer types, and very frequently is found in pancreatic cancer. The microscopic size of nerve fibers within mouse pancreas renders the study of PNI difficult in orthotopic murine models. Here, we describe a heterotopic in vivo model of PNI, where we inject syngeneic pancreatic cancer cell line Panc02-H7 into the murine sciatic nerve. In this model, sciatic nerves of anesthetized mice are exposed and injected with cancer cells. The cancer cells invade in the nerves proximally toward the spinal cord from the point of injection. The invaded sciatic nerves are then extracted and processed with OCT for frozen sectioning. H&amp;E and immunofluorescence staining of these sections allow quantification of both the degree of invasion and changes in protein expression. This model can be applied to a variety of studies on PNI given its versatility. Using mice with different genetic modifications and/or different types of cancer cells allows for investigation of the cellular and molecular mechanisms of PNI and for different cancer types. Furthermore, the effects of therapeutic agents on nerve invasion can be studied by applying treatment to these mice.

This method describes the surgical implantation of pancreatic cancer cells into the murine sciatic nerve to create an in vivo model of quantifiable nerve invasion.&#160;Figure 1 illustrates the anatomical location of the sciatic nerve and the site of injection. Figure 2 shows the two sciatic nerves of a nude mouse. A PBS injected nerve (left) may be compared to a nerve injected with MiaPaCa-2 cancer cells (right). The ne...

Watch this Scientific Journal Video about An In Vivo Murine Sciatic Nerve Model of Perineural Invasion at JoVE.com

An In Vivo Murine Sciatic Nerve Model of Perineural Invasion

We describe an in vivo murine model of perineural invasion by injecting syngeneic pancreatic cancer cells into the sciatic nerve. The model allows for quantification of the extent of nerve invasion, and supports investigation of the cellular and molecular mechanisms of perineural invasion.

An In Vivo Murine Sciatic Nerve Model of Perineural Invasion

Cancer cells invade nerves through a process termed perineural invasion (PNI), in which cancer cells proliferate and migrate in the nerve ...

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11.9K Views.  Memorial Sloan Kettering Cancer Center. We describe an in vivo murine model of perineural invasion by injecting syngeneic pancreatic cancer cells into the sciatic nerve. The model allows for quantification of the extent of nerve invasion, and supports investigation of the cellular and molecular mechanisms of perineural invasion.

Video: An In Vivo Murine Sciatic Nerve Model of Perineural Invasion

Coculture Assays to Study Macrophage and Microglia Stimulation of Glioblastoma Invasion

Glioblastoma multiforme (grade IV glioma) is a very aggressive human cancer with a median survival of 1 year post diagnosis. Despite the increased understanding of the molecular events that give rise to glioblastomas, this cancer still remains highly refractory to conventional treatment. Surgical resection of high grade brain tumors is rarely complete due to the highly infiltrative nature of glioblastoma cells. Therapeutic approaches which attenuate glioblastoma cell invasion therefore is an attractive option. Our laboratory and others have shown that tumor associated macrophages and microglia (resident brain macrophages) strongly stimulate glioblastoma invasion. The protocol described in this paper is used to model glioblastoma-macrophage/microglia interaction using in vitro culture assays. This approach can greatly facilitate the development and/or discovery of drugs that disrupt the communication with the macrophages that enables this malignant behavior. We have established two robust coculture invasion assays where microglia/macrophages stimulate glioma cell invasion by 5 - 10 fold. Glioblastoma cells labelled with a fluorescent marker or constitutively expressing a fluorescent protein are plated without and with macrophages/microglia on matrix-coated polycarbonate chamber inserts or embedded in a three dimensional matrix. Cell invasion is assessed by using fluorescent microscopy to image and count only invasive cells on the underside of the filter. Using these assays, several pharmacological inhibitors (JNJ-28312141, PLX3397, Gefitinib, and Semapimod), have been identified which block macrophage/microglia stimulated glioblastoma invasion.

Understanding the malignant behavior of cancer requires creating accurate models of how tumor cells interact with components of the tumor microenvironment, such as macrophages. Here we describe two methods to study glioblastoma cell interaction with tumor associated macrophages and microglia where the effect on glioblastoma invasion is assessed.

Glioblastoma multiforme (grade IV glioma) is a very aggressive human cancer with a median survival of 1 year post diagnosis. Despite the increased ...

In Vivo Model for Testing Effect of Hypoxia on Tumor Metastasis

Hypoxia has been implicated in the metastasis of Ewing sarcoma (ES) by clinical observations and in vitro data, yet direct evidence for its pro-metastatic effect is lacking and the exact mechanisms of its action are unclear. Here, we report an animal model that allows for direct testing of the effects of tumor hypoxia on ES dissemination and investigation into the underlying pathways involved. This approach combines two well-established experimental strategies, orthotopic xenografting of ES cells and femoral artery ligation (FAL), which induces hindlimb ischemia. Human ES cells were injected into the gastrocnemius muscles of SCID/beige mice and the primary tumors were allowed to grow to a size of 250 mm3. At this stage either the tumors were excised (control group) or the animals were subjected to FAL to create tumor hypoxia, followed by tumor excision 3 days later. The efficiency of FAL was confirmed by a significant increase in binding of hypoxyprobe-1 in the tumor tissue, severe tumor necrosis and complete inhibition of primary tumor growth. Importantly, despite these direct effects of ischemia, an enhanced dissemination of tumor cells from the hypoxic tumors was observed. This experimental strategy enables comparative analysis of the metastatic properties of primary tumors of the same size, yet significantly different levels of hypoxia. It also provides a new platform to further assess the mechanistic basis for the hypoxia-induced alterations that occur during metastatic tumor progression in vivo. In addition, while this model was established using ES cells, we anticipate that this experimental strategy can be used to test the effect of hypoxia in other sarcomas, as well as tumors orthotopically implanted in sites with a well-defined blood supply route.

In Vivo Model for Testing Effect of Hypoxia on Tumor Metastasis

This manuscript describes the development of an animal model that allows for the direct testing of the effects of tumor hypoxia on metastasis and the deciphering the mechanisms of its action. Although the experiments described here focus on Ewing sarcoma, a similar approach can be applied to other tumor types.

Hypoxia has been implicated in the metastasis of Ewing sarcoma (ES) by clinical observations and in vitro data, yet direct evidence for its pro-metastatic ...

A Model for Perineural Invasion in Head and Neck Squamous Cell Carcinoma

Perineural invasion (PNI) is found in approximately 40% of head and neck squamous cell carcinomas (HNSCC). Despite multimodal treatment with surgery, radiation, and chemotherapy, locoregional recurrences and distant metastases occur at higher rates, and overall survival is decreased by 40% compared to HNSCC without PNI. In vitro studies of the pathways involved in HNSCC PNI have historically been challenging given the lack of a consistent, reproducible assay. Described here is the adaptation of the dorsal root ganglion (DRG) assay for the examination of PNI in HNSCC. In this model, DRG are harvested from the spinal column of a sacrificed nude mouse and placed within a semisolid matrix. Over the subsequent days, neurites are generated and grow in a radial pattern from the cell bodies of the DRG. HNSCC cell lines are then placed peripherally around the matrix and invade preferentially along the neurites toward the DRG. This method allows for rapid evaluation of multiple treatment conditions, with very high assay success rates and reproducibility.

Perineural invasion (PNI) is a common feature of head and neck squamous cell carcinoma (HNSCC), conferring lower survival rates. Its mechanisms are poorly understood. Utilizing neurites generated from murine dorsal root ganglia confined to a semisolid matrix, the pathways involved in the PNI of HNSCC cell lines can be investigated.

Perineural invasion (PNI) is found in approximately 40% of head and neck squamous cell carcinomas (HNSCC). Despite multimodal treatment with surgery, ...

A Mouse Model of Fatigue Induced by Peripheral Irradiation

Cancer-related fatigue (CRF) is a distressing and costly condition that often affects patients receiving cancer treatments, including radiation therapy. Here we describe a method using targeted peripheral irradiation to induce fatigue-like behavior in mice. With appropriate shielding, the irradiation targets the lower abdominal/pelvic region of the mouse, sparing the brain, in an effort to model radiation treatment received by individuals with pelvic cancers. We deliver an irradiation dose that is sufficient to induce fatigue-like behavior in mice, measured by voluntary wheel-running activity (VWRA), without causing obvious morbidity. Since wheel running is a normal, voluntary behavior in mice, its use should have little confounding effect on other behavioral tests or biological measures. Hence, wheel running can be used as a feasible outcome measure in understanding the behavioral and biological correlates of fatigue. CRF is a complex condition with frequent comorbidities, and likely has causes related both to cancer and its various treatments. The methods described in this paper are useful for investigating radiation-induced changes that contribute to the development of CRF and, more generally, to explore the biological networks that can explain the development and persistence of a peripherally-triggered but centrally-driven behavior like fatigue.

We describe a method using targeted peripheral irradiation to induce fatigue-like behavior in mice. The selected non-lethal irradiation dose leads to a week-long reduction in voluntary wheel-running activity.

Cancer-related fatigue (CRF) is a distressing and costly condition that often affects patients receiving cancer treatments, including radiation therapy. ...

Moving Upwards: A Simple and Flexible In Vitro Three-dimensional Invasion Assay Protocol

Although 3D invasion assays have been developed, the challenge remains to study cells without affecting the integrity of their microenvironment. Traditional 3D assays such as the Boyden Chamber require that cells are displaced from the original culture location and moved to a new environment. Not only does this disrupt the cellular processes that are intrinsic to the microenvironment, but it often results in a loss of cells. These problems are especially challenging when dealing with cells that are either rare, or extremely sensitive to their microenvironment. Here, we describe the development of a 3D invasion assay that avoids both concerns. In this assay, cells are plated within a small well and an ECM matrix containing a chemoattractant is laid atop the cells. This requires no cell displacement, and allows the cells to invade upwards into the matrix. In this assay, cell invasion as well as cell morphology can be assessed within the collagen gel. Using this assay, we characterize the invasive capacity of rare and sensitive cells; the hybrid cells resulting from fusion between breast cancer cells MCF7 and mesenchymal/multipotent stem/stroma cells (MSCs).

Moving Upwards: A Simple and Flexible In Vitro Three-dimensional Invasion Assay Protocol

This protocol describes an inverted vertical invasion assay that could be used to quantify the migration and invasion capabilities of cells in a three-dimensional setting while preserving the cell microenvironment. This assay is suitable for rare and/or sensitive cells.

Although 3D invasion assays have been developed, the challenge remains to study cells without affecting the integrity of their microenvironment. ...

In Vivo EPR Assessment of pH, pO2, Redox Status, and Concentrations of Phosphate and Glutathione in the Tumor Microenvironment

This protocol demonstrates the capability of low-field electron paramagnetic resonance (EPR)-based techniques in combination with functional paramagnetic probes to provide quantitative information on the chemical tumor microenvironment (TME), including pO2, pH, redox status, concentrations of interstitial inorganic phosphate (Pi), and intracellular glutathione (GSH). In particular, an application of a recently developed soluble multifunctional trityl probe provides unsurpassed opportunity for in vivo concurrent measurements of pH, pO2 and Pi in Extracellular space (HOPE probe). The measurements of three parameters using a single probe allow for their correlation analyses independent of probe distribution and time of the measurements.

In Vivo EPR Assessment of pH, pO2, Redox Status, and Concentrations of Phosphate and Glutathione in the Tumor Microenvironment

Low-field (L-band, 1.2 GHz) electron paramagnetic resonance using soluble nitroxyl and trityl probes is demonstrated for assessment of physiologically important parameters in the tumor microenvironment in mouse models of breast cancer.

This protocol demonstrates the capability of low-field electron paramagnetic resonance (EPR)-based techniques in combination with functional paramagnetic ...

Immunophenotyping of Orthotopic Homograft (Syngeneic) of Murine Primary KPC Pancreatic Ductal Adenocarcinoma by Flow Cytometry

Homograft (syngeneic) tumors are the workhorse of today&#39;s immuno-oncology (I/O) preclinical research. The tumor microenvironment (TME), particularly its immune-components, is vital to the prognosis and prediction of treatment outcomes, especially those of immunotherapy. TME immune-components are composed of different subsets of tumor-infiltrating immune cells assessable by multi-color FACS. Pancreatic ductal adenocarcinoma (PDAC) is among the deadliest malignances lacking good treatment options, thus an urgent and unmet medical need. One important reason for its non-responsiveness to various therapies (chemo-, targeted, I/O) has been its abundant TME, consisting of fibroblasts and leukocytes that protect tumor cells from these therapies. Orthotopically implanted PDAC is believed to more accurately recapture the TME of human pancreatic cancers than conventional subcutaneous (SC) models.
Homograft tumors (KPC) are transplants of mouse spontaneous PDAC originating from genetically engineered KPC-mice (KrasG12D/+/P53-/-/Pdx1-Cre) (KPC-GEMM). The primary tumor tissue is cut into small fragments (~2 mm3) and transplanted subcutaneously (SC) to the syngeneic recipients (C57BL/6, 7&#8211;9 weeks old). The homografts were then surgically orthotopically transplanted onto the pancreas of new C57BL/6 mice, along with SC-implantation, which reached tumor volumes of 300&#8211;1,000 mm3 by 17 days. Only tumors of 400&#8211;600 mm3 were harvested per approved autopsy procedure and cleaned to remove the adjacent non-tumor tissues. They were dissociated per protocol using a tissue dissociator into single-cell suspensions, followed by staining with designated panels of fluorescently-labeled antibodies for various markers of different immune cells (lymphoid, myeloid and NK, DCs). The stained samples were analyzed using multi-color FACS to determine numbers of immune cells of different lineages, as well as their relative percentage within tumors. The immune profiles of orthotopic tumors were then compared to those of SC tumors. The preliminary data demonstrated significantly elevated infiltrating TILs/TAMs in tumors over the pancreas, and higher B-cell infiltration into orthotopic rather than SC tumors.

Immunophenotyping of Orthotopic Homograft Syngeneic of Murine Primary KPC Pancreatic Ductal Adenocarcinoma by Flow Cytometry

The experimental procedure on the immunophenotyping of murine orthotopic PDAC homografts aims at profiling the tumor immuno-microenvironment. Tumors are orthotopically implanted via surgery. Tumors of 200&#8211;600 mm3 in size were harvested and dissociated to prepare single-cell suspensions, followed by multi-immune marker FACS analysis using different fluorescently-labeled antibodies.

Homograft (syngeneic) tumors are the workhorse of today&#39;s immuno-oncology (I/O) preclinical research. The tumor microenvironment (TME), particularly ...

A Simple Migration/Invasion Workflow Using an Automated Live-cell Imager

Cancer cell mobility is crucial for the initiation of metastasis. Therefore, investigation of the cell movement and invasive capacity is of great significance. Migration assays provide basic insight of cell movement at a 2D level, whereas invasion assays are more physiologically relevant, mimicking in vivo cancer cell dislodgment from the original site and invading through the extracellular matrix. The current protocol provides a single workflow for migration and invasion assays. Together with the integrated automated microscopic camera for real-time HD images and built-in analysis module, it gives researchers a time-efficient, simple and reproducible experimental option. This protocol also includes substitutions for the consumables and alternative analysis methods for users to choose from.

The current protocol describes an integrated method investigating cancer cell migration and invasion on a single platform in real-time, providing an easily reproducible and time-efficient option to study cell mobility and morphology.

Cancer cell mobility is crucial for the initiation of metastasis. Therefore, investigation of the cell movement and invasive capacity is of great ...

An Orthotopic Endometrial Cancer Model with Retroperitoneal Lymphadenopathy Made From In Vivo Propagated and Cultured VX2 Cells

Endometrial cancer is the most common gynecologic malignancy in North America and the incidence is rising worldwide. Treatment consists of surgery with or without adjuvant therapy depending on lymph node involvement as determined by lymphadenectomy. Lymphadenectomy is a morbid procedure, which has not been shown to have a therapeutic benefit in many patients, and thus a new method to diagnose lymph node metastases is required. To test novel imaging agents, a reliable model of endometrial cancer with retroperitoneal lymph node metastases is needed. The VX2 endometrial cancer model has been described frequently in the literature; however, significant variation exists with respect to the method of model establishment. Furthermore, no studies have reported on the use of cultured VX2 cells to create this model as only cells propagated in vivo have been previously used. Herein, we present a standardized surgical method and post-operative monitoring method for the establishment of the VX2 endometrial cancer model and report on the first use of cultured VX2 cells to create this model.

This protocol presents a standardized method to grow VX2 cells in culture and to create an orthotopic VX2 model of endometrial cancer with retroperitoneal lymph node metastases in rabbits. Orthotopic endometrial cancer models are important for the pre-clinical study of novel imaging modalities for the diagnosis of lymph node metastases.

Endometrial cancer is the most common gynecologic malignancy in North America and the incidence is rising worldwide. Treatment consists of surgery with or ...

Spatial and Temporal Control of Murine Melanoma Initiation from Mutant Melanocyte Stem Cells

Cutaneous melanoma is well known as the most aggressive skin cancer. Although the risk factors and major genetic alterations continue to be documented with increasing depth, the incidence rate of cutaneous melanoma has shown a rapid and continuous increase during recent decades. In order to find effective preventative methods, it is important to understand the early steps of melanoma initiation in the skin. Previous data has demonstrated that follicular melanocyte stem cells (MCSCs) in the adult skin tissues can act as melanoma cells of origin when expressing oncogenic mutations and genetic alterations. Tumorigenesis arising from melanoma-prone MCSCs can be induced when MCSCs transition from a quiescent to active state. This transition in melanoma-prone MCSCs can be promoted by the modulation of either hair follicle stem cells&#39; activity state or through extrinsic environmental factors such as ultraviolet-B (UV-B). These factors can be artificially manipulated in the laboratory by chemical depilation, which causes transition of hair follicle stem cells and MCSCs from a quiescent to active state, and by UV-B exposure using a benchtop light. These methods provide successful spatial and temporal control of cutaneous melanoma initiation in the murine dorsal skin. Therefore, these in vivo model systems will be valuable to define the early steps of cutaneous melanoma initiation and could be used to test potential methods for tumor prevention.

The following procedure describes a method for spatial and temporal control of melanocytic tumor initiation in murine dorsal skin, using a genetically engineered mouse model. This protocol describes macroscopic as well as microscopic cutaneous melanoma initiation.

Cutaneous melanoma is well known as the most aggressive skin cancer. Although the risk factors and major genetic alterations continue to be documented ...