Name: targeted and selective treatment of pluripotent stem cell-derived teratomas using external beam radiation in a small-animal model
Uploaded: 2019-02-17T13:00:00
Description: Watch this Scientific Journal Video about Targeted and Selective Treatment of Pluripotent Stem Cell-derived Teratomas Using External Beam Radiation in a Small-animal Model at JoVE.com

The authors would like to thank the National Institutes of Health R01 HL134830 (PKN), K08 HL135343 (KS), and 5F32HL134221 (JWR); the Howard Hughes Medical Institute (ASL); and the Stanford Cardiovascular Institute (ASL) for their support.

This animal experiment was approved and performed under the Institutional Review Board and the Administrative Panel on Laboratory Animal Care at Stanford University.
1. Cell Culture of iPSCs
<ol>
	<li>Grow human iPSCs derived by lentiviral reprogramming on 6-well plates coated with basement membrane matrix (e.g., matrigel, referred to as matrix hereon).</li>
	<li>Daily change the media of the iPSCs with enriched culture medium (see Table of Materials) incubating at 37&#160;&...

<ol>
	<li>Sallam, K., Wu, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Embryonic+stem+cell+biology:+insights+from+molecular+imaging.">Embryonic stem cell biology: insights from molecular imaging.</a> Methods in Molecular Biology. 660, 185-199 (2010).</li><li>Lee, A. S., Tang, C., Rao, M. S., Weissman, I. L., Wu, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tumorigenicity+as+a+clinical+hurdle+for+pluripotent+stem+cell+therapies.">Tumorigenicity as a clinical hurdle for pluripotent stem cell therapies.</a> Nature Medicine. 19 (8), 998-1004 (2013).</li><li>Amariglio, N., 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=Donor-derived+brain+tumor+following+neural+stem+cell+transplantation+in+an+ataxia+telangiectasia+patient.">Donor-derived brain tumor following neural stem cell transplantation in an ataxia telangiectasia patient.</a> PLOS Medicine. 6 (2), e1000029 (2009).</li><li>Kuriyan, A. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vision+Loss+after+Intravitreal+Injection+of+Autologous+&amp;#34;Stem+Cells&amp;#34;+for+AMD.">Vision Loss after Intravitreal Injection of Autologous &amp;#34;Stem Cells&amp;#34; for AMD.</a> The New England Journal of Medicine. 376 (11), 1047-1053 (2017).</li><li>Berkowitz, A. L., 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=Glioproliferative+Lesion+of+the+Spinal+Cord+as+a+Complication+of+&amp;#34;Stem-Cell+Tourism&amp;#34.">Glioproliferative Lesion of the Spinal Cord as a Complication of &amp;#34;Stem-Cell Tourism&amp;#34.</a> The New England Journal of Medicine. 375, 196-198 (2016).</li><li>Zhang, W. Y., de Almeida, P. E., Wu, J. 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T., Magnus, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Wrongful+termination:+lessons+from+the+Geron+clinical+trial.">Wrongful termination: lessons from the Geron clinical trial.</a> STEM CELLS Translational Medicine. 3 (12), 1398-1401 (2014).</li><li>Strauss, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Geron+trial+resumes,+but+standards+for+stem+cell+trials+remain+elusive.">Geron trial resumes, but standards for stem cell trials remain elusive.</a> Nature Biotechnology. 28 (10), 989-990 (2010).</li><li>Coghlan, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unexpected+mutations+put+stem+cell+trial+on+hold.">Unexpected mutations put stem cell trial on hold.</a> New Scientist. 227 (3033), 9 (2015).</li><li>Tang, 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=An+antibody+against+SSEA-5+glycan+on+human+pluripotent+stem+cells+enables+removal+of+teratoma-forming+cells.">An antibody against SSEA-5 glycan on human pluripotent stem cells enables removal of teratoma-forming cells.</a> Nature Biotechnology. 29 (9), 829-834 (2011).</li><li>Lee, A. 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=Effects+of+cell+number+on+teratoma+formation+by+human+embryonic+stem+cells.">Effects of cell number on teratoma formation by human embryonic stem cells.</a> Cell Cycle. 8 (16), 2608-2612 (2009).</li><li>Tano, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+in+vitro+method+for+detecting+undifferentiated+human+pluripotent+stem+cells+as+impurities+in+cell+therapy+products+using+a+highly+efficient+culture+system.">A novel in vitro method for detecting undifferentiated human pluripotent stem cells as impurities in cell therapy products using a highly efficient culture system.</a> PLoS One. 9 (10), e110496 (2014).</li><li>Kuroda, T., 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=Highly+sensitive+in+vitro+methods+for+detection+of+residual+undifferentiated+cells+in+retinal+pigment+epithelial+cells+derived+from+human+iPS+cells.">Highly sensitive in vitro methods for detection of residual undifferentiated cells in retinal pigment epithelial cells derived from human iPS cells.</a> PLoS One. 7 (5), e37342 (2012).</li><li>Cao, F., 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+visualization+of+embryonic+stem+cell+survival,+proliferation,+and+migration+after+cardiac+delivery.">In vivo visualization of embryonic stem cell survival, proliferation, and migration after cardiac delivery.</a> Circulation. 113 (7), 1005-1014 (2006).</li><li>Cao, F., 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=Molecular+imaging+of+embryonic+stem+cell+misbehavior+and+suicide+gene+ablation.">Molecular imaging of embryonic stem cell misbehavior and suicide gene ablation.</a> Cloning Stem Cells. 9 (1), 107-117 (2007).</li><li>Kotini, A. G., de Stanchina, E., Themeli, M., Sadelain, M., Papapetrou, E. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Escape+Mutations,+Ganciclovir+Resistance,+and+Teratoma+Formation+in+Human+iPSCs+Expressing+an+HSVtk+Suicide+Gene.">Escape Mutations, Ganciclovir Resistance, and Teratoma Formation in Human iPSCs Expressing an HSVtk Suicide Gene.</a> Molecular Therapy - Nucleic Acids. 5, e284 (2016).</li><li>Smith, A. 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=Apoptotic+susceptibility+to+DNA+damage+of+pluripotent+stem+cells+facilitates+pharmacologic+purging+of+teratoma+risk.">Apoptotic susceptibility to DNA damage of pluripotent stem cells facilitates pharmacologic purging of teratoma risk.</a> STEM CELLS Translational Medicine. 1 (10), 709-718 (2012).</li><li>Choo, A. B., 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=Selection+against+undifferentiated+human+embryonic+stem+cells+by+a+cytotoxic+antibody+recognizing+podocalyxin-like+protein-1.">Selection against undifferentiated human embryonic stem cells by a cytotoxic antibody recognizing podocalyxin-like protein-1.</a> Stem Cells. 26 (6), 1454-1463 (2008).</li><li>Yorke, E., Gelblum, D., Ford, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Patient+safety+in+external+beam+radiation+therapy.">Patient safety in external beam radiation therapy.</a> American Journal of Roentgenology. 196 (4), 768-772 (2011).</li><li>Zhou, 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=Development+of+a+micro-computed+tomography-based+image-guided+conformal+radiotherapy+system+for+small+animals.">Development of a micro-computed tomography-based image-guided conformal radiotherapy system for small animals.</a> International Journal of Radiation Oncology &#8226; Biology &#8226; Physics. 78 (1), 297-305 (2010).</li><li>Slatkin, D. N., Spanne, P., Dilmanian, F. A., Gebbers, J. O., Laissue, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Subacute+neuropathological+effects+of+microplanar+beams+of+x-rays+from+a+synchrotron+wiggler.">Subacute neuropathological effects of microplanar beams of x-rays from a synchrotron wiggler.</a> Proceedings of the National Academy of Sciences of the United States of America. 92 (19), 8783-8787 (1995).</li><li>Lee, A. 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=Brief+Report:+External+Beam+Radiation+Therapy+for+the+Treatment+of+Human+Pluripotent+Stem+Cell-Derived+Teratomas.">Brief Report: External Beam Radiation Therapy for the Treatment of Human Pluripotent Stem Cell-Derived Teratomas.</a> Stem Cells. 35 (8), 1994-2000 (2017).</li><li>Berkowitz, A. L., 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=Glioproliferative+Lesion+of+the+Spinal+Cord+as+a+Complication+of+&amp;#34;Stem-Cell+Tourism&amp;#34.">Glioproliferative Lesion of the Spinal Cord as a Complication of &amp;#34;Stem-Cell Tourism&amp;#34.</a> The New England Journal of Medicine. 375 (2), 196-198 (2016).</li><li>Swijnenburg, R. 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=In+vivo+imaging+of+embryonic+stem+cells+reveals+patterns+of+survival+and+immune+rejection+following+transplantation.">In vivo imaging of embryonic stem cells reveals patterns of survival and immune rejection following transplantation.</a> Stem Cells and Development. 17 (6), 1023-1029 (2008).</li><li>Cao, F., 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=Noninvasive+de+novo+imaging+of+human+embryonic+stem+cell-derived+teratoma+formation.">Noninvasive de novo imaging of human embryonic stem cell-derived teratoma formation.</a> Cancer Research. 69 (7), 2709-2713 (2009).</li><li>Priddle, 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=Bioluminescence+imaging+of+human+embryonic+stem+cells+transplanted+in+vivo+in+murine+and+chick+models.">Bioluminescence imaging of human embryonic stem cells transplanted in vivo in murine and chick models.</a> Cloning and Stem Cells. 11 (2), 259-267 (2009).</li><li>Dale, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dose-rate+effects+in+targeted+radiotherapy.">Dose-rate effects in targeted radiotherapy.</a> Physics in Medicine &amp; Biology. 41 (10), 1871-1884 (1996).</li></ol>

Preclinical data and anecdotal cases from victims of &#34;stem cell tourism&#34; confirm that the risk of developing teratomas is a serious drawback associated with PSC treatments23. Development of careful approaches to prevent and treat the neoplastic risk associated with stem cell therapies is, therefore, an important step in facilitating the clinical translation of regenerative stem cell therapies. In this article, we described a method of therapeutic targeting of PSC-associated teratomas using...

The development of stem cell therapies for tissue regeneration has encountered a number of barriers in the past several decades, hampering efforts for efficient clinical deployment. These hurdles include poor cell retention at sites of delivery, stem cell immunogenicity, and the neoplastic potential to form teratomas1. Tumorigenicity is of particular clinical concern as it can potentially harm stem cell transplant recipients2. Accounts of tumor formation due to unregulated stem cell injections have already been reported in multiple clinical settings3,4,5. The potential for teratoma formation is the most frequently cited clinical concern in pluripotent stem cell (PSC) development and has resulted in delays and cancellations of multiple high-profile embryonic stem cell (ESC) and induced pluripotent stem cell (iPSC) trials6,7,8,9. Thus, there is a pressing need for a translational investigation dedicated toward providing appropriate treatment, should these iatrogenic tumors arise.
To date, most strategies to control stem cell misbehavior have focused on reducing the number of PSCs with tumorigenic potential2,10. Unfortunately, only a small number of residual cells (e.g., 1 x 104 to 1 x 105 cells11) is required for teratoma formation, which is far below the detection limit quoted by currently available assays12,13. Other limitations of using these preseparation methods include low efficiency and high expense, reliance on single-cell suspensions that may not be appropriate for newer tissue-engineering approaches, and the potential impairment of cell survival and engraftment.
Few studies have addressed treatment options following teratoma formation. Perhaps the most well-studied strategy is the incorporation of &#34;suicide&#34; genes into stem cells14,15. This method involves genetically manipulating the stem cells to incorporate an inducible apoptosis-activating gene that can be activated by pharmacological stimulation postinjection, thereby providing a rescue approach if injected cells produce teratomas. This approach, however, suffers from significant drawbacks, including off-target effects of genetic modifications of PSCs and the potential for a gradual development of drug resistance16. A similar approach utilizes small molecules to induce selective cell death of PSCs via the inhibition of anti-apoptotic pathways17. Other groups have targeted cell death of PSCs using antibodies against pluripotency surface markers, such as podocalyxin-like protein-1 (PODXL)18. The timing of small-molecule or antibody delivery stands to have a significant impact on the therapeutic potential of PSCs if delivered too early and may lack therapeutic efficacy if delivered too late. In addition, the systemic effects of small molecules and antibodies used in this fashion have not been studied.
An alternative approach to treating these tumors relies on using external beam radiation therapy (EBRT). EBRT is one of the primary modalities currently employed in the treatment of solid tumors19. Innovations in EBRT, including the development of the proton beam and stereotactic radiosurgery, have enabled the enhanced targeting of pathological structures while avoiding damage to normal tissue, making conformal EBRT ideal for addressing teratoma formation in anatomically sensitive structures20. Additionally, this method avoids the genetic manipulation or viral transduction of stem cells, which are both fraught with additional clinical safety and efficacy concerns15. Finally, advances in micro-irradiators have enabled the application of EBRT in rodents21.
In this article, we demonstrate how to create a small-animal model of teratoma formation by injecting human iPSCs in mice. We then show how to apply EBRT to selectively eradicate these tumors in vivo with minimal damage to surrounding tissue. This approach provides a targeted therapy for PSC-derived teratomas while avoiding the off-target effects of the systemic delivery of biological molecules and peptides and the genetic manipulation of the PSCs. For investigational purposes, we offer an optional step to transduce stem cells with reporter genes to track tumor response to radiation therapy via bioluminescence imaging (BLI).

<table>
	<tbody>
		<tr>
			<td>Induced Pluripotent Stem Cell Control Line</td>
			<td>Stanford University</td>
			<td>Nguyen Lab</td>
			<td>Cell culture of iPSC</td>
		</tr>
		<tr>
			<td>Corning matrigel basement membrane matrix 354234</td>
			<td>Fisher Scientific</td>
			<td>CB-40234</td>
			<td>Cell culture of iPSC</td>
		</tr>
		<tr>
			<td>Essential 8 culture medium</td>
			<td>ATCC-The global bioresource center</td>
			<td>30-2203</td>
			<td>Cell culture of iPSC</td>
		</tr>
		<tr>
			<td>Tryple E</td>
			<td>Gibco</td>
			<td>12605-036</td>
			<td>Cell culture of iPSC</td>
		</tr>
		<tr>
			<td>Y27632 inhibitor 2 HCL (ROCK Inhibitor)</td>
			<td>Fisher Scientific</td>
			<td>S104950MG</td>
			<td>Cell culture of iPSC</td>
		</tr>
		<tr>
			<td>Lentivirus</td>
			<td>Cyagen</td>
			<td>P170721-1001cjn</td>
			<td>Transduction of iPSC with double fusion reporter gene</td>
		</tr>
		<tr>
			<td>Polyrbrene Infection/Transfection Reagent</td>
			<td>Millipore Sigma</td>
			<td>TR-1003-G</td>
			<td>Transduction of iPSC with double fusion reporter gene</td>
		</tr>
		<tr>
			<td>Fluc-eGFP reporter gene driven by ubiquitin promoter</td>
			<td>Stanford University</td>
			<td>Sam Gambhir lab</td>
			<td>Transduction of iPSC with double fusion reporter gene</td>
		</tr>
		<tr>
			<td>D-luciferin</td>
			<td>Perkin Elmer</td>
			<td>122799</td>
			<td>Transduction of iPSC with double fusion reporter gene and BLI</td>
		</tr>
		<tr>
			<td>Flow cytometer (BD FACSARIA III)</td>
			<td>BD Biosciences&#160;</td>
			<td>FACSAria</td>
			<td>Transduction of iPSC with double fusion reporter gene</td>
		</tr>
		<tr>
			<td>microplate spectrofluorometer (Glomax Navigator System)</td>
			<td>Promega Bio Systems, Sunnyvale, CA</td>
			<td>GM2000</td>
			<td>Transduction of iPSC with double fusion reporter gene</td>
		</tr>
		<tr>
			<td>Xenogen IVIS 200&#160;</td>
			<td>Perkin Elmer</td>
			<td>124262</td>
			<td>BLI</td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>Sigma-Aldrich</td>
			<td>CDS019936</td>
			<td>irradiation</td>
		</tr>
		<tr>
			<td>X-Rad SmART image-guided irradiator&#160;</td>
			<td>Precision X-ray Inc., North Branford, CT</td>
			<td>X-Rad SmART</td>
			<td>irradiation</td>
		</tr>
		<tr>
			<td>RT_Image software package</td>
			<td>Stanford University (http://rtimage.sourceforge.net/)</td>
			<td>RT_Image v0.2&#946;</td>
			<td>Irradiation</td>
		</tr>
	</tbody>
</table>

targeted and selective treatment of pluripotent stem cell-derived teratomas using external beam radiation in a small-animal model

The growing number of victims of &#34;stem cell tourism,&#34; the unregulated transplantation of stem cells worldwide, has raised concerns about the safety of stem cell transplantation. Although the transplantation of differentiated rather than undifferentiated cells is common practice, teratomas can still arise from the presence of residual undifferentiated stem cells at the time of transplant or from spontaneous mutations in differentiated cells. Because stem cell therapies are often delivered into anatomically sensitive sites, even small tumors can be clinically devastating, resulting in blindness, paralysis, cognitive abnormalities, and cardiovascular dysfunction. Surgical access to these sites may also be limited, leaving patients with few therapeutic options. Controlling stem cell misbehavior is, therefore, critical for the clinical translation of stem cell therapy.
External beam radiation offers an effective means of delivering targeted therapy to decrease the teratoma burden while minimizing injury to surrounding organs. Additionally, this method avoids genetic manipulation or viral transduction of stem cells-which are associated with additional clinical safety and efficacy concerns. Here, we describe a protocol to create pluripotent stem cell-derived teratomas in mice and to apply external beam radiation therapy to selectively ablate these tumors in vivo.

Injected mice typically will demonstrate teratoma growth formation after 4&#8211;8 weeks as confirmed by BLI imaging (Figure 2). Tumors will shrink dramatically when irradiated with a cumulative dose of 18 Gy given one month after cell delivery, resulting in a significant decrease in luciferase signal (Figure 2). Importantly, normal tissues taken 5 mm from the irradiated site do not appear to have any significant damage (<strong ...

Watch this Scientific Journal Video about Targeted and Selective Treatment of Pluripotent Stem Cell-derived Teratomas Using External Beam Radiation in a Small-animal Model at JoVE.com

Targeted and Selective Treatment of Pluripotent Stem Cell-derived Teratomas Using External Beam Radiation in a Small-animal Model

Research on treatment strategies for pluripotent stem cell-derived teratomas is important for the clinical translation of stem cell therapy. Here, we describe a protocol to, first, generate stem cell-derived teratomas in mice and, then, to selectively target and treat these tumors in vivo using a small-animal irradiator.

The growing number of victims of &#34;stem cell tourism,&#34; the unregulated transplantation of stem cells worldwide, has raised concerns about the ...

The overall goal of this procedure is to selectively target stem cell-derived teratomas in mice for evaluation of the in vivo effectiveness of small animal external beam radiation therapy. The main advantage of external radiation beam therapy is that it is a targeted therapy for stem cell associated teramtomas that avoids the off-targets adverse effects of systemically delivered therapies. Advances in external beam radiation therapy have enabled the specific targeting of small teratomas while avoiding damage to normal tissues, making this therapy ideal for treating radiation sensitive teratomas.This method can not only provide insight into optimizing strategies for cell therapies, it also has the potential to become clinically applicable in human therapies. Begin by taking a six-well plate containing iPSCs. To induce tetratoma formation in immunodeficient animals add one milliliter of recombinant cell dissociation enzyme mix per well of the 6-well plate containing human induced pluripotent stem cells transduced with a double fusion reporter gene for a five minute incubation at room temperature.At the end of the incubation disperse the cells by pipetting and stop the enzymatic reaction by adding an equal volume of cell culture medium to each well. Pull the single cell suspensions in a 15 milliliter conical tube for counting. After centrifugation is complete, aspirate the supernatant and resuspend the pellet in 30 microliters of Matrigel matrix solution and place the tube on ice.If utilizing double fusion reportagen transfected cells, these double positive affect cells should also be suspended in 30 microliters of matrix. Next, load each cell population into a one milliliter syringe equipped with 28.5 gauge needle and confirm a lack of response to toe pinch in each anesthetized eight to 10 week old athymic nude recipient mouse. Then, subcutaneously inject one cell matrix mixture into the dorsal flank of each recipient animal.At the appropriate experimental time point after inoculation inject 375 milligrams per kilogram of deluciferon intraperitoneally into each recipient. After 10 minutes image the bioluminescence signal in each anesthetized reporter probe injected animal for 30 minutes using one minute acquisition windows at five minute intervals, according to standard bioluminescence imaging protocols. For teratoma irradiation, at the appropriate experimental time point, first place an anesthetized recipient animal onto the bed of an image-guided preclinical irradiator and acquire a set of 400 projection micro-computed tomography images over 360 degrees using a 40 peak kilovoltage, 2 milliamp x-ray beam, and reconstruct the image into volumetric images with an isotropic pixel size of 0.2 millimeters.It is critical to reconstruct volumetric images of the teratomas. These images will help to plan the radiation treatments for the specific delivery of the therapy to the teratomas only, while minimizing any off-target radiation of the surrounding tissues. Then use the micro-CT images and the RT image software package to plan a radiation treatment protocol.Administer the treatment for three consecutive days to deliver a total of 18 grays to the target tumor. The injected mice typically demonstrate teratoma growth formation four to eigth weeks after tumor cell injection as confirmed by bioluminescence imaging. When irradiated with a cumulative does of 18 grays one month after cell delivery the tumors will shrink dramatically resulting in a significant coincident decrease in luciferase signal.Importantly, as these images illustrate, normal tissue biopsies harvested five milliliters from the irradiated site do not appear to sustain any significant damage. After watching this video, you should have a clear understanding of how to create stem cell derived teratomas in vivo and to effectively and safely treat them with external beam radiation. This simple approach requires the acquisition of high resolution CT images of a subject after which a series of radiation beam therapies could be prescribed to irradiate the target tumors, while avoiding adjacent tissue.Don't forget that working with radiation can be extremely hazardous and that precautions, such as using the appropriate shields, should always be taken while performing this procedure.

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Protocol for Long Duration Whole Body Hyperthermia in Mice

Hyperthermia is a general term used to define the increase in core body temperature above normal. It is often used to describe the increased core body temperature that is observed during fever. The use of hyperthermia as an adjuvant has emerged as a promising procedure for tumor regression in the field of cancer biology. For this purpose, the most important requirement is to have reliable and uniform heating protocols. We have developed a protocol for hyperthermia (whole body) in mice. In this protocol, animals are exposed to cycles of hyperthermia for 90 min followed by a rest period of 15 min. During this period mice have easy access to food and water. High body temperature spikes in the mice during first few hyperthermia exposure cycles are prevented by immobilizing the animal. Additionally, normal saline is administered in first few cycles to minimize the effects of dehydration. This protocol can simulate fever like conditions in mice up to 12-24 hr. We have used 8-12 weeks old BALB/Cj female mice to demonstrate the protocol.

This paper describes a protocol for whole body hyperthermia in mice that can stimulate fever like conditions up to 12-24 hr.

Hyperthermia is a general term used to define the increase in core body temperature above normal. It is often used to describe the increased core body ...

Assessment of Cardiac Function and Myocardial Morphology Using Small Animal Look-locker Inversion Recovery (SALLI) MRI in Rats

Small animal magnetic resonance imaging is an important tool to study cardiac function and changes in myocardial tissue. The high heart rates of small animals (200 to 600 beats/min) have previously limited the role of CMR imaging. Small animal Look-Locker inversion recovery (SALLI) is a T1 mapping sequence for small animals to overcome this problem 1. T1 maps provide quantitative information about tissue alterations and contrast agent kinetics. It is also possible to detect diffuse myocardial processes such as interstitial fibrosis or edema 1-6. Furthermore, from a single set of image data, it is possible to examine heart function and myocardial scarring by generating cine and inversion recovery-prepared late gadolinium enhancement-type MR images 1.
	The presented video shows step-by-step the procedures to perform small animal CMR imaging. Here it is presented with a healthy Sprague-Dawley rat, however naturally it can be extended to different cardiac small animal models.

Assessment of Cardiac Function and Myocardial Morphology Using Small Animal Look-locker Inversion Recovery SALLI MRI in Rats

Contrast enhanced cardiac magnetic resonance (CMR) imaging allows comprehensive in vivo assessment of the heart in small animal models of cardiovascular disease. Here we detail the procedures to perform CMR imaging, reconstruction and analysis using Small Animal Lock-Locker Inversion Recovery (SALLI) in rats.

Small animal magnetic resonance  imaging is an important tool to study cardiac function and changes in myocardial  tissue. The high heart rates of small ...

Studying Pancreatic Cancer Stem Cell Characteristics for Developing New Treatment Strategies

Pancreatic ductal adenocarcinoma (PDAC) contains a subset of exclusively tumorigenic cancer stem cells (CSCs) which have been shown to drive tumor initiation, metastasis and resistance to radio- and chemotherapy. Here we describe a specific methodology for culturing primary human pancreatic CSCs as tumor spheres in anchorage-independent conditions. Cells are grown in serum-free, non-adherent conditions in order to enrich for CSCs while their more differentiated progenies do not survive and proliferate during the initial phase following seeding of single cells. This assay can be used to estimate the percentage of CSCs present in a population of tumor cells. Both size (which can range from 35 to 250 micrometers) and number of tumor spheres formed represents CSC activity harbored in either bulk populations of cultured cancer cells or freshly harvested and digested tumors 1,2. Using this assay, we recently found that metformin selectively ablates pancreatic CSCs; a finding that was subsequently further corroborated by demonstrating diminished expression of pluripotency-associated genes/surface markers and reduced in vivo tumorigenicity of metformin-treated cells. As the final step for preclinical development we treated mice bearing established tumors with metformin and found significantly prolonged survival. Clinical studies testing the use of metformin in patients with PDAC are currently underway (e.g., NCT01210911, NCT01167738, and NCT01488552). Mechanistically, we found that metformin induces a fatal energy crisis in CSCs by enhancing reactive oxygen species (ROS) production and reducing mitochondrial transmembrane potential. In contrast, non-CSCs were not eliminated by metformin treatment, but rather underwent reversible cell cycle arrest. Therefore, our study serves as a successful example for the potential of in vitro sphere formation as a screening tool to identify compounds that potentially target CSCs, but this technique will require further in vitro and in vivo validation to eliminate false discoveries.

Pancreatic cancer stem cells (CSCs) can be expanded in vitro using the anchorage-independent sphere culture technique, which represents a powerful tool to study CSC biology and can serve as the first step to develop novel CSC-targeting therapies. Here the methodology for expanding, analyzing and targeting of pancreatic CSCs is provided.

Pancreatic ductal adenocarcinoma (PDAC) contains a subset of exclusively tumorigenic cancer stem cells (CSCs) which have been shown to drive tumor ...

Scleral Cross-linking Using Riboflavin and Ultraviolet-A Radiation for Prevention of Axial Myopia in a Rabbit Model

Myopic individuals, especially those with severe myopia, are at higher-than-normal risk of cataract, glaucoma, retinal detachment and chorioretinal abnormalities. In addition, pathological myopia is a common irreversible cause of visual impairment and blindness1-3. Our study demonstrates the effect of scleral crosslinking using riboflavin and ultraviolet-A radiation on the development of axial myopia in a rabbit model. The axial length of the eyeball was measured by A-scan ultrasound in New Zealand white rabbits aged 13 days (male and female). The eye then underwent 360&#176; conjunctival peritomy with scleral crosslinking, followed by tarsorrhaphy. Axial elongation was induced in 13 day-old New Zealand rabbits by suturing their right eye eyelids (tarsorrhaphy). The eyes were divided into quadrants, and every quadrant had two scleral irradiation zones, each with an area of 0.2 cm&#178; and a radius of 4 mm. Crosslinking was performed by dropping 0.1% dextran-free riboflavin-5-phosphate onto the irradiation zones 20 sec before ultraviolet-A irradiation and every 20 sec during the 200 sec irradiation time. UVA radiation (370 nm) was applied perpendicular to the sclera at 57 mW/cm&#178; (total UVA light dose, 57 J/cm&#178;). Tarsorrhaphies were removed on day 55, followed by repeated axial length measurements. This study demonstrates that scleral crosslinking with riboflavin and ultraviolet-A radiation effectively prevents occlusion-induced axial elongation in a rabbit model.

We demonstrate the effect of scleral crosslinking with riboflavin and UVA on an axial elongation rabbit eye. Axial elongation was induced in 13 day-old New Zealand rabbits (male and female) by suturing their right eye eyelids (tarsorrhaphy).

Myopic individuals, especially those with severe myopia, are at higher-than-normal risk of cataract, glaucoma, retinal detachment and chorioretinal ...

In Vivo Evaluation of Fracture Callus Development During Bone Healing in Mice Using an MRI-compatible Osteosynthesis Device for the Mouse Femur

Endochondral fracture healing is a complex process involving the development of fibrous, cartilaginous, and osseous tissue in the fracture callus. The amount of the different tissues in the callus provides important information on the fracture healing progress. Available in vivo techniques to longitudinally monitor the callus tissue development in preclinical fracture-healing studies using small animals include digital radiography and &#181;CT imaging. However, both techniques are only able to distinguish between mineralized and non-mineralized tissue. Consequently, it is impossible to discriminate cartilage from fibrous tissue. In contrast, magnetic resonance imaging (MRI) visualizes anatomical structures based on their water content and might therefore be able to noninvasively identify soft tissue and cartilage in the fracture callus. Here, we report the use of an MRI-compatible external fixator for the mouse femur to allow MRI scans during bone regeneration in mice. The experiments demonstrated that the fixator and a custom-made mounting device allow repetitive MRI scans, thus enabling longitudinal analysis of fracture-callus tissue development.

In Vivo Evaluation of Fracture Callus Development During Bone Healing in Mice Using an MRI-compatible Osteosynthesis Device for the Mouse Femur

The evaluation of tissue development in the fracture callus during endochondral bone healing is essential to monitor the healing process. Here, we report the use of a magnetic resonance imaging (MRI)-compatible external fixator for the mouse femur to allow MRI scans during bone regeneration in mice.

Endochondral fracture healing is a complex process involving the development of fibrous, cartilaginous, and osseous tissue in the fracture callus. The ...

Radiation Planning Assistant - A Streamlined, Fully Automated Radiotherapy Treatment Planning System

The Radiation Planning Assistant (RPA) is a system developed for the fully automated creation of radiotherapy treatment plans, including volume-modulated arc therapy (VMAT) plans for patients with head/neck cancer and 4-field box plans for patients with cervical cancer. It is a combination of specially developed in-house software that uses an application programming interface to communicate with a commercial radiotherapy treatment planning system. It also interfaces with a commercial secondary dose verification software. The necessary inputs to the system are a Treatment Plan Order, approved by the radiation oncologist, and a simulation computed tomography (CT) image, approved by the radiographer. The RPA then generates a complete radiotherapy treatment plan. For the cervical cancer treatment plans, no additional user intervention is necessary until the plan is complete. For head/neck treatment plans, after the normal tissue and some of the target structures are automatically delineated on the CT image, the radiation oncologist must review the contours, making edits if necessary. They also delineate the gross tumor volume. The RPA then completes the treatment planning process, creating a VMAT plan. Finally, the completed plan must be reviewed by qualified clinical staff.

Radiation therapy is a highly complex cancer treatment that requires multiple specialists to create a treatment plan and provide quality assurance (QA) prior to delivery to a patient. This protocol describes the use of a fully automated system, the Radiation Planning Assistant (RPA), to create high-quality radiation treatment plans.

The Radiation Planning Assistant (RPA) is a system developed for the fully automated creation of radiotherapy treatment plans, including volume-modulated ...

A Small Animal Model of Ex Vivo Normothermic Liver Perfusion

There is a significant shortage of liver allografts available for transplantation, and in response the donor criteria have been expanded. As a result, normothermic ex vivo liver perfusion (NEVLP) has been introduced as a method to evaluate and modify organ function. NEVLP has many advantages in comparison to hypothermic and subnormothermic perfusion including reduced preservation injury, restoration of normal organ function under physiologic conditions, assessment of organ performance, and as a platform for organ repair, remodeling, and modification. Both murine and porcine NEVLP models have been described. We demonstrate a rat model of NEVLP and use this model to show one of its important applications &#8212; the use of a therapeutic molecule added to liver perfusate. Catalase is an endogenous reactive oxygen species (ROS) scavenger and has been demonstrated to decrease ischemia-reperfusion in the eye, brain, and lung. Pegylation has been shown to target catalase to the endothelium. Here, we added pegylated-catalase (PEG-CAT) to the base perfusate and demonstrated its ability to mitigate liver preservation injury. An advantage of our rodent NEVLP model is that it is inexpensive in comparison to larger animal models. A limitation of this study is that it does not currently include post-perfusion liver transplantation. Therefore, prediction of the function of the organ post-transplantation cannot be made with certainty. However, the rat liver transplant model is well established and certainly could be used in conjunction with this model. In conclusion, we have demonstrated an inexpensive, simple, easily replicable NEVLP model using rats. Applications of this model can include testing novel perfusates and perfusate additives, testing software designed for organ evaluation, and experiments designed to repair organs.

A Small Animal Model of Ex Vivo Normothermic Liver Perfusion

There is a significant liver donor shortage, and criteria for liver donors have been expanded. Normothermic ex vivo liver perfusion (NEVLP) has been developed to evaluate and modify organ function. This study demonstrates a rat model of NEVLP and tests the ability of pegylated-catalase, to mitigate liver preservation injury.

There is a significant shortage of liver allografts available for transplantation, and in response the donor criteria have been expanded. As a result, ...

Isometric Contractility Measurement of the Mouse Mesenteric Artery Using Wire Myography

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and drugs. It is widely used in many studies on the physiological functions of vascular smooth muscle, the pathogenesis of vascular diseases such as hypertension, and the development of smooth muscle relaxant drugs. The mouse is a widely used model animal with a large pool of disease models and genetically modified strains. We introduced this method to measure the isometric contraction of mouse mesenteric artery in detail. A 1.4-mm segment of mouse mesenteric resistance artery was isolated and mounted on a myograph chamber by passing two steel wires through its lumen. After equilibration and normalization steps, the vessel segment was potentiated by a high-K+ solution twice prior to the contraction assay. As an example of the application of this method in drug development, we measured the relaxant effect of a novel natural substance, neoliensinine, isolated from a Chinese herb, embryos of the lotus seed (Nelumbo nucifera Gaertn.) on mouse mesenteric arteries. The vessel segments mounted on the myograph chamber were stimulated with a high-K+ solution. When the force tension reached a stable sustained phase, cumulative doses of neoliensinine were added to the chamber. We found that neoliensinine had a dose-dependent relaxant effect on smooth muscle contraction, thus suggesting that it bears potential activity against hypertension. In addition, as the vessel segment can survive at least 4 hours after mounting and maintain contractility induced by the high-K+ solution for many times, we suggest that the wire myograph system may be used for the time-consuming process of drug screening.

The wire myograph technique is used to investigate vascular smooth muscle functions and screen new drugs. We report a detailed protocol for measuring the isometric contractility of the mouse mesenteric artery and for screening new relaxants of vascular smooth muscle.

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and ...

Sarcomere Shortening of Pluripotent Stem Cell-Derived Cardiomyocytes using Fluorescent-Tagged Sarcomere Proteins.

Pluripotent stem cell-derived cardiomyocytes (PSC-CMs) can be produced from both embryonic and induced pluripotent stem (ES/iPS) cells. These cells provide promising sources for cardiac disease modeling. For cardiomyopathies, sarcomere shortening is one of the standard physiological assessments that are used with adult cardiomyocytes to examine their disease phenotypes. However, the available methods are not appropriate to assess the contractility of PSC-CMs, as these cells have underdeveloped sarcomeres that are invisible under phase-contrast microscopy. To address this issue and to perform sarcomere shortening with PSC-CMs, fluorescent-tagged sarcomere proteins and fluorescent live-imaging were used. Thin Z-lines and an M-line reside at both ends and the center of a sarcomere, respectively. Z-line proteins &#8212;&#160;&#945;-Actinin (ACTN2), Telethonin (TCAP), and actin-associated LIM protein (PDLIM3) &#8212; and one M-line protein &#8212; Myomesin-2 (Myom2) &#8212;&#160;were tagged with fluorescent proteins. These tagged proteins can be expressed from endogenous alleles as knock-ins or from adeno-associated viruses (AAVs). Here, we introduce the methods to differentiate mouse and human pluripotent stem cells to cardiomyocytes, to produce AAVs, and to perform and analyze live-imaging. We also describe the methods for producing polydimethylsiloxane (PDMS) stamps for a patterned culture of PSC-CMs, which facilitates the analysis of sarcomere shortening with fluorescent-tagged proteins. To assess sarcomere shortening, time-lapse images of the beating cells were recorded at a high framerate (50-100 frames per second) under electrical stimulation (0.5-1 Hz). To analyze sarcomere length over the course of cell contraction, the recorded time-lapse images were subjected to SarcOptiM, a plug-in for ImageJ/Fiji. Our strategy provides a simple platform for investigating cardiac disease phenotypes in PSC-CMs.

This method can be used to examine sarcomere shortening using pluripotent stem cell-derived cardiomyocytes with fluorescent-tagged sarcomere proteins.

Pluripotent stem cell-derived cardiomyocytes (PSC-CMs) can be produced from both embryonic and induced pluripotent stem (ES/iPS) cells. These cells ...

Ultrasound-Guided Induced Pluripotent Stem Cell-Derived Cardiomyocyte Implantation in Myocardial Infarcted Mice

The key objective of cell therapy after myocardial infarction (MI) is to effectively enhance the cell grafted rate, and human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are a promising cell source for cardiac repair after ischemic damage. However, a low grafted rate is a significant obstacle for effective cardiac tissue regeneration after transplantation. This protocol shows that multiple hiPSC-CM ultrasound-guided percutaneous injections into an MI area effectively increase cell transplantation rates. The study also describes the entire hiPSC-CM culture process, pretreatment, and ultrasound-guided percutaneous delivery methods. In addition, the use of human mitochondrial DNA help detect the absence of hiPSC-CMs in other mouse organs. Lastly, this paper describes the changes in cardiac function, angiogenesis, cell size, and apoptosis at the infarcted border zone in mice 4 weeks after cell delivery. It can be concluded that echocardiography-guided percutaneous injection of the left ventricular myocardium is a feasible, relatively invasive, satisfactory, repeatable, and effective cellular therapy.

Ultrasound-guided cell delivery around the site of myocardial infarction in mice is a safe, effective, and convenient way of cell transplantation.

The key objective of cell therapy after myocardial infarction (MI) is to effectively enhance the cell grafted rate, and human induced pluripotent stem ...