Name: implantation and evaluation of melanoma in the murine choroid via optical coherence tomography
Uploaded: 2022-12-02T14:10:00
Description: Watch this Scientific Journal Video about Implantation and Evaluation of Melanoma in the Murine Choroid via Optical Coherence Tomography at JoVE.com

This study was supported in part by grant 1304/20 from the Israel Science Foundation (ISF), Israel, for Arie Marcovich. We thank Shahar Ish-Shalom&#160;and Ady Yosipovich, from the Department of Pathology, Kaplan Medical Center, Rehovot, Israel, for histology analysis.

The experiments in the protocol were approved by the Israeli National Council on Animal Experimentation and comply with the ARVO Statement for using Animals in Ophthalmic and Vision Research. Female C57BL/6 mice, aged 8-10 weeks, were used for the present study and were exposed to 12/12 h light-dark cycles. The animals were obtained from a commercial source (see Table of Materials).
1. Cell culture
<ol>
	<li>Culture B16LS9 cells in RPMI 1640 medium, suppleme...

<ol>
	<li>Jager, M. J., 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=Uveal+melanoma.">Uveal melanoma.</a> Nature Reviews Disease Primers. 6 (1), 1-25 (2020).</li><li>Bustamante, P., Piquet, L., Landreville, S., Burnier, J. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Uveal+melanoma+pathobiology:+Metastasis+to+the+liver.">Uveal melanoma pathobiology: Metastasis to the liver.</a> Seminars in Cancer Biology. 71, 65-85 (2021).</li><li>Damato, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ocular+treatment+of+choroidal+melanoma+in+relation+to+the+prevention+of+metastatic+death-A+personal+view.">Ocular treatment of choroidal melanoma in relation to the prevention of metastatic death-A personal view.</a> Progress in Retinal and Eye Research. 66, 187-199 (2018).</li><li>Jouhi, S., 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=The+small+fatal+choroidal+melanoma+study.+A+survey+by+the+European+Ophthalmic+Oncology+Group.">The small fatal choroidal melanoma study. A survey by the European Ophthalmic Oncology Group.</a> American Journal of Ophthalmology. 202, 100-108 (2019).</li><li>Cao, J., Jager, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+eye+models+for+uveal+melanoma.">Animal eye models for uveal melanoma.</a> Ocular Oncology and Pathology. 1 (3), 141-150 (2015).</li><li>Uner, O. E., Gandrakota, N., Azarcon, C. P., Grossniklaus, H. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+of+uveal+melanoma.">Animal models of uveal melanoma.</a> Annals of Eye Science. 7, 21-30 (2022).</li><li>Yang, H., Dithmar, S., Grossniklaus, H. 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M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Murine+models+of+liver+metastasis.">Murine models of liver metastasis.</a> Invasion &amp; Metastasis. 14 (1-6), 349-361 (1994).</li><li>Ashur-Fabian, O., 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=Tetrac+delayed+the+onset+of+ocular+melanoma+in+an+orthotopic+mouse+model.">Tetrac delayed the onset of ocular melanoma in an orthotopic mouse model.</a> Frontiers in Endocrinology. 12, 632335 (2019).</li><li>Elia, 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=Mechanisms+regulating+c-met+overexpression+in+liver-metastatic+B16-LS9+melanoma+cells.">Mechanisms regulating c-met overexpression in liver-metastatic B16-LS9 melanoma cells.</a> Journal of Cellular Biochemistry. 81 (3), 477-487 (2001).</li><li>Harning, R., Szalay, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ocular+metastasis+of+in+vivo+and+in+vitro+derived+syngeneic+murine+melanoma.">Ocular metastasis of in vivo and in vitro derived syngeneic murine melanoma.</a> Investigative Ophthalmology &amp; Visual Science. 28 (9), 1599-1604 (1987).</li><li>Ezra-Elia, R., 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=Can+an+in+vivo+imaging+system+be+used+to+determine+localization+and+biodistribution+of+AAV5-mediated+gene+expression+following+subretinal+and+intravitreal+delivery+in+mice.">Can an in vivo imaging system be used to determine localization and biodistribution of AAV5-mediated gene expression following subretinal and intravitreal delivery in mice.</a> Experimental Eye Research. 176, 227-234 (2018).</li><li>Notting, I. C., 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=Whole-body+bioluminescent+imaging+of+human+uveal+melanoma+in+a+new+mouse+model+of+local+tumor+growth+and+metastasis.">Whole-body bioluminescent imaging of human uveal melanoma in a new mouse model of local tumor growth and metastasis.</a> Investigative Ophthalmology &amp; Visual Science. 46 (5), 1581-1587 (2005).</li><li>Yang, H., 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=In-vivo+xenograft+murine+human+uveal+melanoma+model+develops+hepatic+micrometastases.">In-vivo xenograft murine human uveal melanoma model develops hepatic micrometastases.</a> Melanoma Research. 18 (2), 95-103 (2008).</li><li>Murthy, R. K., Haji, S., Sambhav, K., Grover, S., Chalam, K. 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D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phenotyping+of+mouse+models+with+OCT.">Phenotyping of mouse models with OCT.</a> Methods in Molecular Biology. 1834, 285-291 (2019).</li><li>Zaks, O., 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=In-vivo+imaging+for+assessing+tumor+growth+in+mouse+models+of+ocular+melanoma.">In-vivo imaging for assessing tumor growth in mouse models of ocular melanoma.</a> Experimental Eye Research. 204, 108431 (2021).</li><li>Brar, V. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=American+Academy+of+Ophthalmology+2022-2023+BCSC.+2.">American Academy of Ophthalmology 2022-2023 BCSC. 2.</a> Fundamentals and principles of ophthalmology. , (2022).</li><li>Duker, J. 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Uveal melanoma is a devastating disease for which novel therapeutic approaches are greatly needed. However, research on uveal melanoma and potential treatments is limited by the technical challenges of uveal melanoma animal models1,25. Ocular tumors, which are induced by intraocular injection of cancer cells, are highly variable in both localization and size, likely due to the small dimensions of the mouse eye. Such variability is an obstacle to the comprehensive...

Uveal melanoma (UM) is the most frequent intraocular primary malignancy in adults. Approximately 90% of ocular melanomas originate from melanocytes in the choroid region of the uveal tract1. UM is a major cause of morbidity and mortality, as it is estimated that close to 50% of patients develop metastatic disease, with the liver being the major site of metastasis2. Early treatment of primary lesions may reduce the chance of metastases, yet no effective treatment prevents metastases formation3.
The standard treatment of uveal melanoma includes irradiation therapy, which is associated with loss of vision due to optic neuropathy, retinopathy, dry eye syndrome, and cataract. Surgical resection is typically delayed until the growth of the lesion is recognized and characterized. However, such a delay may allow metastatic disease development4. In some cases, futile enucleation is required. Of course, this radical procedure compromises vision and results in dramatic aesthetic deterioration.
There have been many efforts dedicated to developing experimental models to study uveal melanoma. Preclinical animal models that allow accurate assessment of this malignancy are key for investigating novel diagnostic and therapeutic strategies for uveal melanoma. Experimental animal models of ocular melanoma are mainly based on the inoculation of tumor cells in mice, rats, and rabbits5,6. Mouse models are cost-effective and widely used for melanoma studies due to their rapid reproduction rate and high genome similarity to humans. The murine cutaneous melanoma cell line B16 is commonly utilized to inoculate C57BL6 mice and induce syngeneic tumors. When using this model to induce uveal melanoma, tumor-bearing eyes typically need to be enucleated 7-14 days after inoculation. Further, B16 is a highly invasive model. The immune-privileged nature of the eye supports metastasis, and metastases may typically be detected 3-4 weeks after tumor cell inoculation. Subcultures of the original B16 line display distinct metastatic properties6. For example, the Queens melanoma line has a high metastatic rate7,8. The B16LS9 cell line has dendritic cell morphology and was derived from liver metastases of C57BL/6 mice injected with the parental cutaneous melanoma line B16F19. When injected into the posterior compartment of the eye, these cells were shown to form intraocular tumors, which histologically resemble human uveal melanoma and form liver-specific metastases in C57BL/6, but not Balb/C, mice10,11,12. Genetically, the cells are characterized by higher expression of the c-met proto-oncogene, which acts as a cellular receptor for hepatocyte growth factor13. In contrast, B16F10, the 10th passage of the parental B16, primarily metastasizes to the lungs when inoculated intraocularly14.&#160;Both B16F10 and B16LS9 are pigmented12.
Several key challenges limit the success of murine uveal melanoma models. First, tumor cell reflux may lead to extraocular or subconjunctival melanoma. Second, tumor growth after intraocular inoculation of melanoma cells is often highly variable, posing difficulties in evaluating treatment and progress. Another major difficulty is the limited ability to follow tumor growth in vivo. While bioluminescent imaging, such as of luciferase expressing tumors, is commonly used to monitor ocular tumor growth15,16, it cannot provide information on the intraocular location of the tumor. Therefore, evaluation of the tumor is typically performed following enucleation of the eye10,17. This greatly limits the ability to characterize tumor progression and response to treatments extensively. Another major hurdle in studying uveal melanoma is the difficulty in monitoring lesions in pigmented mice. New approaches, which overcome these difficulties, are required to promote the research of uveal melanoma in animal models.
Optical coherence tomography (OCT) provides distinctive capabilities to image deep into the different sections of the eye in high resolution, which is unparalleled by other methodologies, including&#160;ultrasound18,19. OCT imaging has been used in animal models to study various ocular diseases20. Recently, OCT imaging was demonstrated as noninvasive means to evaluate intraocular tumor growth21. The protocol described here depicts the implantation of melanoma cells in the murine choroid and the utilization of OCT to predict intraocular tumor localization and size at the time of cell inoculation.

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	<tbody>
		<tr>
			<td>10 &#956;L glass syringe (Hamilton Co., Bonaduz, Switzerland)</td>
			<td>Hamilton</td>
			<td>721711</td>
			<td></td>
		</tr>
		<tr>
			<td>30 G needles</td>
			<td>BD Microbalance</td>
			<td>2025-01</td>
			<td></td>
		</tr>
		<tr>
			<td>Atipamezole hydrochloride</td>
			<td>Orion Phrma</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>B16LS9 cells</td>
			<td>from Hans Grossniklaus USA</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Buprenorphine&#160;</td>
			<td>richter pharma</td>
			<td>102047</td>
			<td></td>
		</tr>
		<tr>
			<td>C57BL/6 female mice</td>
			<td>Envigo</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Essential vitamin mixture</td>
			<td>satorius</td>
			<td>01-025-1A</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal bovine serum</td>
			<td>rhenium</td>
			<td>10270106</td>
			<td></td>
		</tr>
		<tr>
			<td>HEPES</td>
			<td>satorius</td>
			<td>03-025-1B</td>
			<td></td>
		</tr>
		<tr>
			<td>Hydroxyethylcellulose 1.4% eye drops</td>
			<td>Fisher Pharmaceutical</td>
			<td>390862</td>
			<td></td>
		</tr>
		<tr>
			<td>InSight OCT segmentation software&#160;</td>
			<td>Phoenix Micron, Inc&#160;</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ketamine</td>
			<td>bremer pharma GMBH (medimarket)</td>
			<td>17889</td>
			<td></td>
		</tr>
		<tr>
			<td>L-glutamine</td>
			<td>satorius</td>
			<td>03-020-1B</td>
			<td></td>
		</tr>
		<tr>
			<td>Medetomidine&#160;</td>
			<td>zoetis (vetmarket)</td>
			<td>102532</td>
			<td></td>
		</tr>
		<tr>
			<td>Ofloxacin 0.3% eye drops</td>
			<td>allergan</td>
			<td>E92170</td>
			<td></td>
		</tr>
		<tr>
			<td>Optical coherence tomography&#160;</td>
			<td>Phoenix Micron, Inc&#160;</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Oxybuprocaine 0.4%</td>
			<td>Fisher Pharmaceutical</td>
			<td>393050</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin-streptomycin-amphoteracin</td>
			<td>satorius</td>
			<td>03-033-1B</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphate buffered saline (PBS)&#160;</td>
			<td>satorius</td>
			<td>02-023-1a</td>
			<td></td>
		</tr>
		<tr>
			<td>RPMI cell media</td>
			<td>satorius</td>
			<td>01-104-1A</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium pyruvate</td>
			<td>satorius</td>
			<td>03-042-1B</td>
			<td></td>
		</tr>
		<tr>
			<td>Surgical microscope</td>
			<td>Zeiss</td>
			<td>OPMI-6 CFC</td>
			<td></td>
		</tr>
		<tr>
			<td>Tropicamide 0.5%</td>
			<td>Fisher Pharmaceutical</td>
			<td>390723</td>
			<td></td>
		</tr>
	</tbody>
</table>

implantation and evaluation of melanoma in the murine choroid via optical coherence tomography

Establishing experimental choroidal melanoma models is challenging in terms of the ability to induce tumors at the correct localization. In addition, difficulties in observing posterior choroidal melanoma in vivo limit tumor location and growth evaluation in real-time. The approach described here optimizes techniques for establishing choroidal melanoma in mice via a multi-step sub-choroidal B16LS9 cell injection procedure. To enable precision in injecting into the small dimensions of the mouse uvea, the complete procedure is performed under a microscope. First, a conjunctival peritomy is formed in the dorsal-temporal area of the eye. Then, a tract into the sub-choroidal space is created by inserting a needle through the exposed sclera. This is followed by the insertion of a blunt needle into the tract and the injection of melanoma cells into the choroid. Immediately after injection, noninvasive optical coherence tomography (OCT) imaging is utilized to determine tumor location and progress. Retinal detachment is evaluated as a predictor of tumor site and size. The presented method enables the reproducible induction of choroid-localized melanoma in mice and the live imaging of tumor growth evaluation. As such, it provides a valuable tool for studying intraocular tumors.

Eyes were examined via OCT immediately after injection of the B16LS9 cells. Local retinal detachment was observed after injection. The mice exhibited three patterns of RD: focal (Figure 2, upper panel), leakage to the vitreous (Figure 2, middle panel), and extended RD (Figure 2, bottom panel). Extended RD is likely caused by damage from the injection. There was an association between the pattern of RD immediately after inje...

Watch this Scientific Journal Video about Implantation and Evaluation of Melanoma in the Murine Choroid via Optical Coherence Tomography at JoVE.com

Implantation and Evaluation of Melanoma in the Murine Choroid via Optical Coherence Tomography

The present protocol describes the implantation and evaluation of melanoma in the murine choroid utilizing optical coherence tomography.

Implantation and Evaluation of Melanoma in the Murine Choroid via Optical Coherence Tomography

Establishing experimental choroidal melanoma models is challenging in terms of the ability to induce tumors at the correct localization. In addition, ...

Establishing tumors as the posterior part of the eye is challenging. This method enables the induction of reproducible choroidal melanoma tumors in mice, and live imaging of tumor growth for evaluation. This protocol utilizes OCT live imaging to assess the location of the tumors already at the time of tumor cell inoculation, and to follow tumor growth in live animals.Uveal melanoma is a devastating disease with close to a 50%rate of metastasis. Developing experimental models is key to advancing research aimed at new therapeutic possibilities. An advantage of this method is that the immediate assessment of the success of injection allows to reach study groups with homogenous tumors and continuously follow them by live imaging.To examine tumor progression. Injecting into the small mouse's eyes requires practice. The ability to visualize the injected cells allows you to assess your success immediately and repeat with more mice as necessary.Demonstrating the procedure will be Dr.Dimitri Gaber from the Ophthalmology Research Laboratory at the Kaplan Medical Center. To begin, apply 0.4%topical ophthalmic anesthetic, Oxybuprocaine to both eyes of the anesthetized mouse. Then topically apply 0.5%Tropicamide to both eyes for dilating the pupils, followed by 1.4%hydroxyethyl cellulose as a lubricant to avoid drying of the eyes.Observe one eye of the mouse under an operating microscope. Hold the eyelids open with sterile intraocular forceps. Then hold the superior temporal limbo-conjunctiva and pull toward an infra nasal position.Secure this position by holding the limbo-conjunctiva throughout the procedure. Using a 30 gauge needle tip make a small conjunctival peritomy in the dorsal temporal area approximately one to two millimeters posterior to the limbus. Remove the excess tendons capsule from the opening of the peritomy.Insert the needle tip to penetrate the sclera creating a track into the subchoroidal space until the brown color of the choroid appears through the exposed white matter of the sclera. Load the cells into a sterile 10 microliter glass Hamilton syringe mounted with a 32 gauge blunt needle twisted at a 45 degree angle. Insert the needle of the loaded syringe approximately two millimeters into the created tract, and inject two microliters of the cell suspension.Hold the needle in place after injection for two to three seconds until all fluid has cleared. Remove the needle by pulling it out gently to avoid leakage from the tract. Immediately after the melanoma cell inoculation, observe the injected eye of the animal by OCT scans.Based on the scans, classify the retinal detachment or RD patterns according to three categories local RD, Leakage Into The Vitreous, or Extended RD.Open an OCT segmentation analysis software to predict the tumor size based on RD height. Measure the height of Local RD in the OCT scans, and classify them into three groups. In the postoperative phase, apply 0.3%of Ofloxacin topically.The OCT-based prediction of tumor growth following subchoroidal cell injection is depicted in this figure. The mice exhibited three patterns of RD, Focal, Leakage To The Vitreous, and Extended RD.There was an association between the pattern of RD immediately after injection, and the localization of the tumors five days after injection. Focal RD was associated with the tumor cell growth that was limited to the choroid.However, observation of cells in the vitreous after injection in animals displaying Focal RD indicated tumor growth in the vitreal cavity and the choroid. when Extended RD was observed after injection, tumors were dispersed throughout the choroid and vitreous after five days. The range of tumor sizes induced in this model can be divided into small, medium, and large.Shown here are representative images of the OCT measurement of RD height after injection, and the corresponding fundus image, a horizontal OCT scan of the tumor height and width on day five after injection, and its corresponding fundus image, and the corresponding H&E stained eye section demonstrating comparable tumor measurements. Tumor volume measurements of mice that presented small, medium or large RD immediately after cell injection are presented here. Adjusting the force of injection can affect tumor size and location.It is important to calibrate this and to evaluate the pattern of induced retinal detachment by OCT after injection. Live imaging of choroidal tumors is an important experimental tool that allows to examine the effect of different factors or potential therapies on tumor progression.

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Cancer Research

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. ...

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

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

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

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

Enrichment and Characterization of the Tumor Immune and Non-immune Microenvironments in Established Subcutaneous Murine Tumors

The tumor immune microenvironment (TIME) has recently been recognized as a critical mediator of treatment response in solid tumors, especially for immunotherapies. Recent clinical advances in immunotherapy highlight the need for reproducible methods to accurately and thoroughly characterize the tumor and its associated immune infiltrate. Tumor enzymatic digestion and flow cytometric analysis allow broad characterization of numerous immune cell subsets and phenotypes; however, depth of analysis is often limited by fluorophore restrictions on panel design and the need to acquire large tumor samples to observe rare immune populations of interest. Thus, we have developed an effective and high throughput method for separating and enriching the tumor immune infiltrate from the non-immune tumor components. The described tumor digestion and centrifugal density-based separation technique allows separate characterization of tumor and tumor immune infiltrate fractions and preserves cellular viability, and thus, provides a broad characterization of the tumor immunologic state. This method was used to characterize the extensive spatial immune heterogeneity in solid tumors, which further demonstrates the need for consistent whole tumor immunologic profiling techniques. Overall, this method provides an effective and adaptable technique for the immunologic characterization of subcutaneous solid murine tumors; as such, this tool can be used to better characterize the tumoral immunologic features and in the preclinical evaluation of novel immunotherapeutic strategies.

Here we describe a method to separate and enrich components of the tumor immune and non-immune microenvironment in established subcutaneous tumors. This technique allows for the separate analysis of tumor immune infiltrate and non-immune tumor fractions which can permit comprehensive characterization of the tumor immune microenvironment.

The tumor immune microenvironment (TIME) has recently been recognized as a critical mediator of treatment response in solid tumors, especially for ...

Longitudinal Morphological and Physiological Monitoring of Three-dimensional Tumor Spheroids Using Optical Coherence Tomography

Tumor spheroids have been developed as a three-dimensional (3D) cell culture model in cancer research and anti-cancer drug discovery. However, currently, high-throughput imaging modalities utilizing bright field or fluorescence detection, are unable to resolve the overall 3D structure of the tumor spheroid due to limited light penetration, diffusion of fluorescent dyes and depth-resolvability. Recently, our lab demonstrated the use of optical coherence tomography (OCT), a label-free and non-destructive 3D imaging modality, to perform longitudinal characterization of multicellular tumor spheroids in a 96-well plate. OCT was capable of obtaining 3D morphological and physiological information of tumor spheroids growing up to about 600 &#181;m in height. In this article, we demonstrate a high-throughput OCT (HT-OCT) imaging system that scans the whole multi-well plate and obtains 3D OCT data of tumor spheroids automatically. We describe the details of the HT-OCT system and construction guidelines in the protocol. From the 3D OCT data, one can visualize the overall structure of the spheroid with 3D rendered and orthogonal slices, characterize the longitudinal growth curve of the tumor spheroid based on the morphological information of size and volume, and monitor the growth of the dead-cell regions in the tumor spheroid based on optical intrinsic attenuation contrast. We show that HT-OCT can be used as a high-throughput imaging modality for drug screening as well as characterizing biofabricated samples.

Optical coherence tomography (OCT), a three-dimensional imaging technology, was used to monitor and characterize the growth kinetics of multicellular tumor spheroids. Precise volumetric quantification of tumor spheroids using a voxel counting approach, and label-free dead tissue detection in the spheroids based on intrinsic optical attenuation contrast, were demonstrated.

Tumor spheroids have been developed as a three-dimensional (3D) cell culture model in cancer research and anti-cancer drug discovery. However, currently, ...

Rapid Generation of Primary Murine Melanocyte and Fibroblast Cultures

Defects in fibroblast or melanocyte function are associated with skin diseases, including poor barrier function, defective wound healing, pigmentation defects and cancer. Vital to the understanding and amelioration of these diseases are experiments in primary fibroblast and melanocyte cultures. Nevertheless, current protocols for melanocyte isolation require that the epidermal and dermal layers of the skin are trypsinized and manually disassociated. This process is time consuming, technically challenging and contributes to inconsistent yields. Furthermore, methods to simultaneously generate pure fibroblast cultures from the same tissue sample are not readily available. Here, we describe an improved protocol for isolating melanocytes and fibroblasts from the skin of mice on postnatal days 0-4. In this protocol, whole skin is mechanically homogenized using a tissue chopper and then briefly digested with collagenase and trypsin. Cell populations are then isolated through selective plating followed by G418 treatment. This procedure results in consistent melanocyte and fibroblast yields from a single mouse in less than 90 min. This protocol is also easily scalable, allowing researchers to process large cohorts of animals without a significant increase in hands-on time. We show through flow cytometric assessments that cultures established using this protocol are highly enriched for melanocytes or fibroblasts.

This protocol outlines a rapid method to simultaneously generate melanocyte and fibroblast cultures from the skin of 0-4 day old mice. These primary cultures can be maintained and manipulated in vitro to study a variety of physiologically relevant processes, including skin cell biology, pigmentation, wound healing and melanoma.

Defects in fibroblast or melanocyte function are associated with skin diseases, including poor barrier function, defective wound healing, pigmentation ...

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 ...

Generation of a Liver Orthotopic Human Uveal Melanoma Xenograft Platform in Immunodeficient Mice

In recent decades, subcutaneously implanted patient-derived xenograft tumors or cultured human cell lines have been increasingly recognized as more representative models to study human cancers in immunodeficient mice than traditional established human cell lines in vitro. Recently, orthotopically implanted patient-derived tumor xenograft (PDX) models in mice have been developed to better replicate features of patient tumors. A liver orthotopic xenograft mouse model is expected to be a useful cancer research platform, providing insights into tumor biology and drug therapy. However, liver orthotopic tumor implantation is generally complicated. Here we describe our protocols for the orthotopic implantation of patient-derived liver-metastatic uveal melanoma tumors. We cultured human liver metastatic uveal melanoma cell lines into immunodeficient mice. The protocols can result in consistently high technical success rates using either a surgical orthotopic implantation technique with chunks of patient-derived uveal melanoma tumor or a needle injection technique with cultured human cell line. We also describe protocols for CT scanning to detect interior liver tumors and for re-implantation techniques using cryopreserved tumors to achieve re-engraftment. Together, these protocols provide a better platform for liver orthotopic tumor mouse models of liver metastatic uveal melanoma in translational research.

Orthotopic human liver metastatic uveal melanoma xenograft mouse models were created using surgical orthotopic implantation techniques with patient-derived tumor chunk and needle injection techniques with cultured human uveal melanoma cell lines.

In recent decades, subcutaneously implanted patient-derived xenograft tumors or cultured human cell lines have been increasingly recognized as more ...

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 ...

In Vitro Evaluation of Oncogenic Transformation in Human Mammary Epithelial Cells

Tumorigenesis is a multi-step process in which cells acquire capabilities&#160;that allow their growth, survival, and dissemination under hostile conditions. Different tests seek to identify and quantify these hallmarks of cancerous cells; however, they often focus on a single aspect of cellular transformation and, in fact, multiple tests are required for their proper characterization. The purpose of this work is to provide researchers with a set of tools to assess cellular transformation in vitro from a broad perspective, thereby making it possible to draw sound conclusions.
A sustained proliferative signaling activation is the major feature of tumoral tissues and can be easily monitored under in vitro conditions by calculating the number of population doublings achieved over time. Besides, the growth of cells in 3D cultures allows their interaction with surrounding cells, resembling what occurs in vivo. This enables the evaluation of cellular aggregation and, together with immunofluorescent labeling of distinctive cellular markers, to obtain information on another relevant feature of tumoral transformation: the loss of proper organization. Another remarkable characteristic of transformed cells is their capacity to grow without attachment to other cells and to the extracellular matrix, which can be evaluated with the anchorage assay.
Detailed experimental procedures to evaluate cell growth rate, to perform immunofluorescent labeling of cell lineage markers in 3D cultures, and to test anchorage-independent cell growth in soft agar are provided. These methodologies are optimized for Breast Primary Epithelial Cells (BPEC) due to its relevance in breast cancer; however, procedures can be applied to other cell types after some adjustments.

This protocol provides experimental in vitro tools to evaluate the transformation of human mammary cells. Detailed steps to follow-up cell proliferation rate, anchorage-independent growth capacity, and distribution of cell lineages in 3D cultures with basement membrane matrix are described.

Tumorigenesis is a multi-step process in which cells acquire capabilities&#160;that allow their growth, survival, and dissemination under hostile ...

Evaluation of the In vivo Antitumor Activity of Polyanhydride IL-1&#945; Nanoparticles

Cytokine therapy is a promising immunotherapeutic strategy that can produce robust antitumor immune responses in cancer patients. The proinflammatory cytokine interleukin-1 alpha (IL-1&#945;) has been evaluated as an anticancer agent in several preclinical and clinical studies. However, dose-limiting toxicities, including flu-like symptoms and hypotension, have dampened the enthusiasm for this therapeutic strategy. Polyanhydride nanoparticle (NP)-based delivery of IL-1&#945; would represent an effective approach in this context since this may allow for a slow and controlled release of IL-1&#945; systemically while reducing toxic side effects. Here an analysis of the antitumor activity of IL-1&#945;-loaded polyanhydride NPs in a head and neck squamous cell carcinoma (HNSCC) syngeneic mouse model is described. Murine oropharyngeal epithelial cells stably expressing HPV16 E6/E7 together with hRAS and luciferase (mEERL) cells were injected subcutaneously into the right flank of C57BL/6J mice. Once tumors reached 3-4 mm in any direction, a 1.5% IL-1a - loaded 20:80 1,8-bis(p-carboxyphenoxy)-3,6-dioxaoctane:1,6-bis(p-carboxyphenoxy)hexane (CPTEG: CPH) nanoparticle (IL-1&#945;-NP) formulation was administered to mice intraperitoneally. Tumor size and body weight were continuously measured until tumor size or weight loss reached euthanasia criteria. Blood samples were taken to evaluate antitumor immune responses by submandibular venipuncture, and inflammatory cytokines were measured through cytokine multiplex assays. Tumor and inguinal lymph nodes were resected and homogenized into a single-cell suspension to analyze various immune cells through multicolor flow cytometry. These standard methods will allow investigators to study the antitumor immune response and potential mechanism of immunostimulatory NPs and other immunotherapy agents for cancer treatment.

Evaluation of the In vivo Antitumor Activity of Polyanhydride IL-1&#945; Nanoparticles

A standard protocol is described to study the antitumor activity and associated toxicity of IL-1&#945; in a syngeneic mouse model of HNSCC.

Cytokine therapy is a promising immunotherapeutic strategy that can produce robust antitumor immune responses in cancer patients. The proinflammatory ...