Name: modeling primary bone tumors and bone metastasis with solid tumor graft implantation into bone
Uploaded: 2020-09-09T13:00:00
Description: Watch this Scientific Journal Video about Modeling Primary Bone Tumors and Bone Metastasis with Solid Tumor Graft Implantation into Bone at JoVE.com

The authors acknowledge the critical contribution of Dr. Beth Chaffee, DVM, PhD, DACVP to the development of this technique.&#160;&#160;

All described animal experiments were approved by the institutional animal care and use committee of University of Cambridge, Cambridge, UK.
1. Preparation of cell lines
<ol>
	<li>Grow cell lines in accordance with the laboratory&#8217;s standard cell culture protocols for traditional cell culture or injection into mice. Standard protocols used here are growth in Dulbecco&#8217;s modified Eagle&#8217;s medium containing 10% fetal bovine serum (FBS), L-glutamine, and penicillin/streptomycin (...

<ol>
	<li>Bryda, E. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Mighty+Mouse:+the+impact+of+rodents+on+advances+in+biomedical+research.">The Mighty Mouse: the impact of rodents on advances in biomedical research.</a> Missouri Medicine. 110 (3), 207-211 (2013).</li><li>Vandamme, T. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+rodents+as+models+of+human+diseases.">Use of rodents as models of human diseases.</a> Journal of Pharmacy and Bioallied Sciences. 6 (1), 2-9 (2014).</li><li>Simmons, J. 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=Animal+Models+of+Bone+Metastasis.">Animal Models of Bone Metastasis.</a> Veterinary Pathology. 52 (5), 827-841 (2015).</li><li>Wolfe, T. D., 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=Effect+of+zoledronic+acid+and+amputation+on+bone+invasion+and+lung+metastasis+of+canine+osteosarcoma+in+nude+mice.">Effect of zoledronic acid and amputation on bone invasion and lung metastasis of canine osteosarcoma in nude mice.</a> Clinical and Experimental Metastasis. 28 (4), 377-389 (2011).</li><li>Wang, 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=The+Clinicopathological+features+and+survival+outcomes+of+patients+with+different+metastatic+sites+in+stage+IV+breast+cancer.">The Clinicopathological features and survival outcomes of patients with different metastatic sites in stage IV breast cancer.</a> BMC Cancer. 19 (1), 1091 (2019).</li><li>James, J. 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=metastases+from+breast+carcinoma:+histopathological+-+radiological+correlations+and+prognostic+features.">metastases from breast carcinoma: histopathological - radiological correlations and prognostic features.</a> British Journal of Cancer. 89 (4), 660-665 (2003).</li><li>Pantel, K., Brakenhoff, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dissecting+the+metastatic+cascade.">Dissecting the metastatic cascade.</a> Nature Reviews Cancer. 4 (6), 448-456 (2004).</li><li>Chaffee, B. K., Allen, 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=A+clinically+relevant+mouse+model+of+canine+osteosarcoma+with+spontaneous+metastasis.">A clinically relevant mouse model of canine osteosarcoma with spontaneous metastasis.</a> In Vivo. 27 (5), 599-603 (2013).</li><li>Munajat, I., Zulmi, W., Norazman, M. Z., Wan Faisham, W. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tumour+volume+and+lung+metastasis+in+patients+with+osteosarcoma.">Tumour volume and lung metastasis in patients with osteosarcoma.</a> Journal of Orthopaedic Surgery (Hong Kong). 16 (2), 182-185 (2008).</li><li>Huang, X., 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=Risk+and+clinicopathological+features+of+osteosarcoma+metastasis+to+the+lung:+A+population-based+study.">Risk and clinicopathological features of osteosarcoma metastasis to the lung: A population-based study.</a> Journal of Bone Oncology. 16, 100230 (2019).</li><li>Li, W., Zhang, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Survival+of+patients+with+primary+osteosarcoma+and+lung+metastases.">Survival of patients with primary osteosarcoma and lung metastases.</a> Journal of BUON. 23 (5), 1500-1504 (2018).</li><li>Campbell, J. P., Merkel, A. R., Masood-Campbell, S. K., Elefteriou, F., Sterling, 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=Models+of+bone+metastasis.">Models of bone metastasis.</a> Journal of Visualized Experiments. (67), e4260 (2012).</li><li>Maloney, 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=Intratibial+Injection+Causes+Direct+Pulmonary+Seeding+of+Osteosarcoma+Cells+and+Is+Not+a+Spontaneous+Model+of+Metastasis:+A+Mouse+Osteosarcoma+Model.">Intratibial Injection Causes Direct Pulmonary Seeding of Osteosarcoma Cells and Is Not a Spontaneous Model of Metastasis: A Mouse Osteosarcoma Model.</a> Clinical Orthopedics and Related Research. 476 (7), 1514-1522 (2018).</li><li>Dai, J., Hensel, J., Wang, N., Kruithof-de Julio, M., Shiozawa, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+models+for+studying+prostate+cancer+bone+metastasis.">Mouse models for studying prostate cancer bone metastasis.</a> BoneKey Reports. 5, 777 (2016).</li><li>Marques da Costa, M. 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=Establishment+and+characterization+of+in+vivo+orthotopic+bioluminescent+xenograft+models+from+human+osteosarcoma+cell+lines+in+Swiss+nude+and+NSG+mice.">Establishment and characterization of in vivo orthotopic bioluminescent xenograft models from human osteosarcoma cell lines in Swiss nude and NSG mice.</a> Cancer Medicine. 7 (3), 665-676 (2018).</li><li>Raheem, 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=A+novel+patient-derived+intra-femoral+xenograft+model+of+bone+metastatic+prostate+cancer+that+recapitulates+mixed+osteolytic+and+osteoblastic+lesions.">A novel patient-derived intra-femoral xenograft model of bone metastatic prostate cancer that recapitulates mixed osteolytic and osteoblastic lesions.</a> Journal of Translational Medicine. 9, 185 (2011).</li><li>Sasaki, H., Iyer, S. V., Sasaki, K., Tawfik, O. W., Iwakuma, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+improved+intrafemoral+injection+with+minimized+leakage+as+an+orthotopic+mouse+model+of+osteosarcoma.">An improved intrafemoral injection with minimized leakage as an orthotopic mouse model of osteosarcoma.</a> Analytical Biochemistry. 486, 70-74 (2015).</li><li>Valastyan, S., Weinberg, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tumor+metastasis:+molecular+insights+and+evolving+paradigms.">Tumor metastasis: molecular insights and evolving paradigms.</a> Cell. 147 (2), 275-292 (2011).</li><li>Yu, 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=Intra-iliac+Artery+Injection+for+Efficient+and+Selective+Modeling+of+Microscopic+Bone+Metastasis.">Intra-iliac Artery Injection for Efficient and Selective Modeling of Microscopic Bone Metastasis.</a> Journal of Visualized Experiments. (115), e53982 (2016).</li><li>Kuchimaru, 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=A+reliable+murine+model+of+bone+metastasis+by+injecting+cancer+cells+through+caudal+arteries.">A reliable murine model of bone metastasis by injecting cancer cells through caudal arteries.</a> Nature Communications. 9 (1), 2981 (2018).</li><li>Haley, H. 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=Enhanced+Bone+Metastases+in+Skeletally+Immature+Mice.">Enhanced Bone Metastases in Skeletally Immature Mice.</a> Tomography. 4 (2), 84-93 (2018).</li><li>Lei, Z. G., Ren, X. H., Wang, S. S., Liang, X. H., Tang, Y. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immunocompromised+and+immunocompetent+mouse+models+for+head+and+neck+squamous+cell+carcinoma.">Immunocompromised and immunocompetent mouse models for head and neck squamous cell carcinoma.</a> Onco Targets and Therapy. 9, 545-555 (2016).</li><li>Lefley, D., 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+clinically+relevant+in+vivo+metastasis+models+using+human+bone+discs+and+breast+cancer+patient-derived+xenografts.">Development of clinically relevant in vivo metastasis models using human bone discs and breast cancer patient-derived xenografts.</a> Breast Cancer Research. 21 (1), 130 (2019).</li><li>Tuveson, D., Clevers, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cancer+modeling+meets+human+organoid+technology.">Cancer modeling meets human organoid technology.</a> Science. 364 (6444), 952-955 (2019).</li></ol>

This report documents our model to create primary bone tumors or bone metastasis following the intratibial implantation of a tumor allograft. We believe that there are several critical steps in this process. A safe anesthetic plane should be established for both subcutaneous injection of the tumor cell suspension and intratibial placement of the resultant tumor fragments. There should be sterile preparation of the surgical site for both removal of the subcutaneous allograft and intratibial placement of the allograft. Tum...

Mouse models of human and animal disease are becoming increasingly popular in biomedical research. The utility of using mice in this context is that their anatomy and physiology are very similar to humans. They have a relatively short gestation period and time in post-natal life to achieve maturity, and are largely associated with a relatively low cost and ease of housing, albeit increasing costs of development or purchase are associated with greater degrees of genetic modification, immunodeficiency, and/or humanization1. Use of inbred strains results in a largely uniform animal population prior to study inclusion. A complete knowledge of their genome suggests a high degree of similarity to humans. Orthologous molecular targets for many disease processes have been identified in the mouse genome and there is now an extensive library of mouse-specific reagents that are easily obtainable. Therefore, they provide the opportunity for relatively high-throughput analysis in a more rapid and less expensive manner when compared to larger animal models1. In addition, with the advent of genetic editing strategies that allows for the overexpression or deletion of certain genes either globally or in a cell type specific manner and/or constitutively or in an inducible manner, they represent a very biologically useful model system for the investigation of human and animal diseases2.
Cancer is one field in which mouse models have great utility. Genetic mouse models of cancer rely on modulation of the expression of either oncogenes or tumor suppressor genes, alone or in combination, for cells to undergo oncogenic transformation. The injection of primary or established tumor cell lines into mice is also performed. The introduction of either cell lines or tissues from humans or other animal species, including mice, remains the most widely used model of cancer in vivo. The use of cells and tissues from dissimilar species (xenografts) in immunocompromised mice is most commonly performed2. However, the use of allograft tumor cells or tissues where both the host and recipient are of the same species allows for the interaction with an intact immune system when combined with the same host mouse strain in syngeneic systems3.
Primary bone tumors or bone metastasis from solid tumors result in painful osteolytic, osteoblastic, or mixed osteolytic/osteoblastic lesions3,4. These tumors compromise bone structure, increasing the risk of pathologic fracture, and leave patients with limited treatment options. Primary bone tumors metastasize to distant organs, with some types capable of spreading to other skeletal sites. In breast cancer patients, bone is the most common site of first metastasis and the most frequent first site of presentation of metastatic disease5,6. In addition, disseminated tumor cells (DTCs) are present in the bone marrow prior to the diagnosis of, and predict the development of, metastasis in other organs7. Therefore, it is believed that cancer cells present in bone are the source of cells that ultimately metastasize to other organ systems. Many mouse models of solid tumor metastasis exist that develop metastasis predominantly in the lung and lymph nodes, and depending on the tumor type and injection technique, potentially other organ systems3. However, mouse models of bone metastasis are lacking that dependably, reproducibly produce site specific skeletal metastasis and develop bone metastasis before mice reach early removal criteria from primary tumor burden or metastasis to other organs. We have reported a model of the primary bone tumor osteosarcoma that relies on the surgical implantation of a solid tumor allograft into the proximal tibia of mice8. Bone tumors formed in 100% of mice and 88% developed pulmonary metastasis. This incidence of metastasis exceeds what is commonly reported clinically in people (~20-50%), but is of great interest since the lung is the most common site of metastasis for osteosarcoma9,10,11. While this model is advantageous in modeling primary bone tumors, it also has great utility in modeling bone metastasis from other osteotropic solid tumors such as breast, lung, prostate, thyroid, hepatic, renal, and gastrointestinal tumors.
The rationale for the development of this model was to develop an alternative to the traditional intra-osseous injection typically into the proximal tibia or distal femur to model primary bone tumors or bone metastasis12. Our primary goal was to alleviate a known limitation of this technique i.e., tumor embolization of the lung. This results in the engraftment of these embolic tumor cells and &#8220;artifactual metastasis&#8221; that do not recapitulate the complete metastatic cascade from an established primary bone tumor that metastasizes to the lungs8,13. This would also be the situation when an established bone metastasis spreads to a distant site. In addition, this technique was, also, developed to produce a model of bone metastasis that would ensure a greater incidence of engraftment and growth of tumors in bone and at a uniform site when compared with orthotopic or intravascular injection techniques. This model has distinct advantages over these described techniques. This model involves controlled, consistent delivery of tumor cells into the bone. It, also, avoids artifactual lung metastasis following pulmonary embolization and establishes a baseline uniform study population. There is the benefit of site-specific tumors with this model without the risk of early removal criteria resulting from primary tumors or metastasis to other organs. Lastly, this model has great utility for modification, including the use of patient-derived xenografts.
The model presented has similarities to direct cell suspension injection into bone following a surgical approach followed by either injection through the cortex or delivery into the marrow cavity after making a small defect in the cortex (with or without reaming out the medullary cavity)8,14,15,16,17. However, the implantation of a tumor allograft makes this technique distinctly different. Therefore, the purpose of this report was to demonstrate this model of primary bone tumors and bone metastasis from solid tumors, which overcomes many limitations of previously described models. Research groups with experience in cell culture, mouse models, mouse anesthesia and surgery, and mouse anatomy are well equipped to reproduce our technique to model primary bone tumors or bone metastasis in mice.

<table>
	<tbody>
		<tr>
			<td>#15 scalpel blade</td>
			<td>Henry Schein Ltd.</td>
			<td>75614</td>
			<td>None</td>
		</tr>
		<tr>
			<td>6-well tissue culture plates</td>
			<td>Thermo Fisher Scientific</td>
			<td>10578911</td>
			<td>Used for mincing tumor pieces. Can also be used for cell culture</td>
		</tr>
		<tr>
			<td>Abrams osteosarcoma cell line</td>
			<td>Not applicable</td>
			<td>Not applicable</td>
			<td>None</td>
		</tr>
		<tr>
			<td>Anesthesia machine with isoflurane vaporiser and oxygen tank(s)</td>
			<td>VetEquip</td>
			<td>901805</td>
			<td>None</td>
		</tr>
		<tr>
			<td>Animal weighing scale</td>
			<td>Kent Scientific</td>
			<td>SCL- 1015</td>
			<td>None</td>
		</tr>
		<tr>
			<td>BALB/c nude mouse (nu/nu)</td>
			<td>Charles River Ltd.</td>
			<td>NA</td>
			<td>6-8 weeks of age. Male or female mice</td>
		</tr>
		<tr>
			<td>Bone cement</td>
			<td>Depuy Synthes</td>
			<td>160504</td>
			<td>Optional use instead of bone wax</td>
		</tr>
		<tr>
			<td>Bone wax</td>
			<td>Ethicon</td>
			<td>W31G</td>
			<td>Optional</td>
		</tr>
		<tr>
			<td>Buprenorphine</td>
			<td>Animalcare Ltd.</td>
			<td>N/A</td>
			<td>Buprecare 0.3 mg/ml Solution for Injection for Dogs and Cats</td>
		</tr>
		<tr>
			<td>Carbon dioxide euthanasia station</td>
			<td>N/A</td>
			<td>N/A</td>
			<td>Should be provided within animal facility</td>
		</tr>
		<tr>
			<td>Cell culture incubator set at 37 &#176;C and 5% carbon dioxide</td>
			<td>Heraeus</td>
			<td>Various</td>
			<td>None</td>
		</tr>
		<tr>
			<td>Chlorhexidine surgical scrub</td>
			<td>Vetoquinol</td>
			<td>411412</td>
			<td>None</td>
		</tr>
		<tr>
			<td>Cryovials (2 ml)</td>
			<td>Thermo Scientific Nalgene</td>
			<td>5000-0020</td>
			<td>Optional if cryopreserving tumor fragments</td>
		</tr>
		<tr>
			<td>D-luciferin (Firefly), potassium salt</td>
			<td>Perkin Elmer</td>
			<td>122799</td>
			<td>Optional if cell line of interest has a bioluminescent reporter gene</td>
		</tr>
		<tr>
			<td>Digital caliper</td>
			<td>Mitutoyo</td>
			<td>500-181-30</td>
			<td>Can be manual</td>
		</tr>
		<tr>
			<td>Digital microradiography cabinet</td>
			<td>Faxitron Bioptics, LLC</td>
			<td>MX-20</td>
			<td>Optional to evaluate bone response to tumor growth</td>
		</tr>
		<tr>
			<td>Dimethyl sulfoxide (DMSO)</td>
			<td>Sigma Aldrich</td>
			<td>1371171000</td>
			<td>Optional if cryopreserving tumor fragments</td>
		</tr>
		<tr>
			<td>Dulbecco&#8217;s modified Eagle&#8217;s medium</td>
			<td>Thermo Fisher Scientific</td>
			<td>11965092</td>
			<td>None</td>
		</tr>
		<tr>
			<td>Ethanol (70%)</td>
			<td>Sigma Aldrich</td>
			<td>2483</td>
			<td>None</td>
		</tr>
		<tr>
			<td>Fetal bovine serum</td>
			<td>Thermo Fisher Scientific</td>
			<td>26140079</td>
			<td>None</td>
		</tr>
		<tr>
			<td>Forceps, Dumont</td>
			<td>Fine Science Tools, Inc.</td>
			<td>11200-33</td>
			<td>None</td>
		</tr>
		<tr>
			<td>Freezer (&#8211; 80 &#176;C)</td>
			<td>Sanyo</td>
			<td>MDF-794C</td>
			<td>Optional if cryopreserving or snap freezing tumor fragments</td>
		</tr>
		<tr>
			<td>Hemocytometer</td>
			<td>Thermo Fisher Scientific</td>
			<td>11704939</td>
			<td>Can also use automated cell counter, if available</td>
		</tr>
		<tr>
			<td>Hypodermic needles (27 gauge)</td>
			<td>Henry Schein Ltd.</td>
			<td>DIS55510</td>
			<td>May also use 25G (DIS55509) and 30G (Catalog DIS599) needles</td>
		</tr>
		<tr>
			<td>Ice</td>
			<td>N/A</td>
			<td>N/A</td>
			<td>Ideally small pieces in a container for syringe and cell suspension storage</td>
		</tr>
		<tr>
			<td>Iris scissors</td>
			<td>Fine Science Tools, Inc.</td>
			<td>14084-08</td>
			<td>None</td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>Henry Schein Ltd.</td>
			<td>1182098</td>
			<td>None</td>
		</tr>
		<tr>
			<td>IVIS Lumina III bioluminescence/fluorescence imaging system</td>
			<td>Perkin Elmer</td>
			<td>CLS136334</td>
			<td>Optional if cell line of interest has bioluminescent or fluorescent reporter genes</td>
		</tr>
		<tr>
			<td>L-glutamine</td>
			<td>Thermofisher scientifc</td>
			<td>25030081</td>
			<td>None</td>
		</tr>
		<tr>
			<td>Liquid nitrogen</td>
			<td>British Oxygen Corporation</td>
			<td>NA</td>
			<td>Optional if cryopreserving or snap freezing tumor fragments</td>
		</tr>
		<tr>
			<td>Liquid nitrogen dewar, 5 litres</td>
			<td>Thermo Fisher Scientific</td>
			<td>TY509X1</td>
			<td>Optional if cryopreserving tumor fragments</td>
		</tr>
		<tr>
			<td>Matrigel&#174; Matrix GFR, LDEV-Free, 5 ml</td>
			<td>Corning Life Sciences</td>
			<td>356230</td>
			<td>Optional. Also available in 10 ml size (354230)</td>
		</tr>
		<tr>
			<td>Microcentrifuge</td>
			<td>Thermo Fisher Scientific</td>
			<td>75002549</td>
			<td>Pellet cells at 1200 rpm for 5-6 minutes</td>
		</tr>
		<tr>
			<td>Mr. Frosty freezing containiner</td>
			<td>Fisher Scientific</td>
			<td>10110051</td>
			<td>Optional if cryopreserving tumor fragments</td>
		</tr>
		<tr>
			<td>NAIR Hair remover lotion/oil</td>
			<td>Thermo Fisher Scientific</td>
			<td>NC0132811</td>
			<td>Can alternatively use an electric clipper with fine blade</td>
		</tr>
		<tr>
			<td>Penicillin/streptomycin</td>
			<td>Sigma-Aldrich</td>
			<td>P4333</td>
			<td>None</td>
		</tr>
		<tr>
			<td>Scalpel handle, #7 Short</td>
			<td>Fine Science Tools, Inc.</td>
			<td>10007-12</td>
			<td>User preference as long as it accepts #15 scalpel blade</td>
		</tr>
		<tr>
			<td>Small animal heated pad</td>
			<td>VetTech</td>
			<td>HE006</td>
			<td>None</td>
		</tr>
		<tr>
			<td>Stereomicroscope</td>
			<td>GT Vision Ltd.</td>
			<td>H600BV1</td>
			<td>None</td>
		</tr>
		<tr>
			<td>Sterile phosphate-buffered saline (PBS)</td>
			<td>Thermo Fisher Scientific</td>
			<td>10010023</td>
			<td>Use for injections and also as part of the surgical scrub, alternating with chlorhexidine</td>
		</tr>
		<tr>
			<td>Tissue adhesive (sterile)</td>
			<td>3M Corporation</td>
			<td>84-1469SB</td>
			<td>Can alternatively use non-absorbable skin suture (6-0 size)</td>
		</tr>
		<tr>
			<td>Trypan blue</td>
			<td>Thermo Fisher Scientific</td>
			<td>5250061</td>
			<td>None</td>
		</tr>
		<tr>
			<td>Trypsin-EDTA</td>
			<td>Thermo Fisher Scientific</td>
			<td>25300054</td>
			<td>Use 0.05%-0.25%</td>
		</tr>
		<tr>
			<td>Tuberculin syringe (1 ml with 0.1 ml gradations)</td>
			<td>Becton Dickinson</td>
			<td>309659</td>
			<td>Slip tip preferred over Luer</td>
		</tr>
		<tr>
			<td>Vented tissue culture flasks, T-75</td>
			<td>Corning Life Sciences</td>
			<td>CLS3290</td>
			<td>Can also use smaller or larger flasks, as needed</td>
		</tr>
	</tbody>
</table>

modeling primary bone tumors and bone metastasis with solid tumor graft implantation into bone

Primary bone tumors or bone metastasis from solid tumors result in painful osteolytic, osteoblastic, or mixed osteolytic/osteoblastic lesions. These lesions compromise bone structure, increase the risk of pathologic fracture, and leave patients with limited treatment options. Primary bone tumors metastasize to distant organs, with some types capable of spreading to other skeletal sites. However, recent evidence suggests that with many solid tumors, cancer cells that have spread to bone may be the primary source of cells that ultimately metastasize to other organ systems. Most syngeneic or xenograft mouse models of primary bone tumors involve intra-osseous (orthotopic) injection of tumor cell suspensions. Some animal models of skeletal metastasis from solid tumors also depend on direct bone injection, while others attempt to recapitulate additional steps of the bone metastatic cascade by injecting cells intravascularly or into the organ of the primary tumor. However, none of these models develop bone metastasis reliably or with an incidence of 100%. In addition, direct intra-osseous injection of tumor cells has been shown to be associated with potential tumor embolization of the lung. These embolic tumor cells engraft but do not recapitulate the metastatic cascade. We reported a mouse model of osteosarcoma in which fresh or cryopreserved tumor fragments (consisting of tumor cells plus stroma) are implanted directly into the proximal tibia using a minimally invasive surgical technique. These animals developed reproducible engraftment, growth, and, over time, osteolysis and lung metastasis. This technique has the versatility to be used to model solid tumor bone metastasis and can readily employ grafts consisting of one or multiple cell types, genetically-modified cells, patient-derived xenografts, and/or labeled cells that can be tracked by optical or advanced imaging. Here, we demonstrate this technique, modeling primary bone tumors and bone metastasis using solid tumor graft implantation into bone.

A positive result would be associated with tumor engraftment and progressive tumor growth over time. Depending on the tumor type, intraosseous tumor growth may be associated with progressive hind limb lameness, but many tumors do not cause lameness despite signs of attendant bone disease. Successful engraftment was documented with advanced imaging, whereby there would be progressive radiographic, &#181;CT, or &#181;MRI changes in the proximal tibia associated with the bone phenotype of the cell line of interest (osteolyt...

Watch this Scientific Journal Video about Modeling Primary Bone Tumors and Bone Metastasis with Solid Tumor Graft Implantation into Bone at JoVE.com

Modeling Primary Bone Tumors and Bone Metastasis with Solid Tumor Graft Implantation into Bone

Bone metastasis models do not develop metastasis uniformly or with a 100% incidence. Direct intra-osseous tumor cell injection can result in embolization of the lung. We present our technique modeling primary bone tumors and bone metastasis using solid tumor graft implantation into bone, leading to reproducible engraftment and growth.

Primary bone tumors or bone metastasis from solid tumors result in painful osteolytic, osteoblastic, or mixed osteolytic/osteoblastic lesions. These ...

This study allows for flexibility in creating primary bone tumors or bone metastasis by placing solid tumor grafts into bone. This technique is a departure from injecting tumor cell suspensions in the bone. This method overcomes the limitation of tumor cell suspension injections lung emboli.Another advantage is creating a more uniform model when compared to spontaneous bone metastasis or after intravascular cell injection. Based on solid tumor graft implantation, possibilities exist beyond human or mouse models, but the use of patient-derived xenografts which can lead to therapies tailored to specific patients. The primary focus is for use at cancer research such as tumor microenvironment, metastasis, drug discovery, cancer genetics, and precision medicine.Visual demonstration is key to showing the key steps of creating the subcutaneous tumor, dissection and creation of the tumor graft, and surgical implantation into the tibia. For subcutaneous tumor induction, harvest the cell line of interest using an appropriate cell dissociation solution and resuspend the cells at a one to two times 10 to the fifth cells to 100 to 150 microliter sterile PBS concentration. Place the cells on ice.Clean the exposed skin with 70%ethanol, and load the cells into a Tuberculin syringe equipped with a 27 gauge needle. Then inject the cell subcutaneously into a region of disinfected skin that will not be impacted by the movement of the shoulder blades. Use a caliper to monitor the size of the subcutaneous tumor overlying the dorsal thorax or abdomen, and measure the animal's body weight weekly to ensure that the tumor does not ulcerate or that the mouse does not meet early removal criteria as established by the Institutional Animal Care and Use Committee.When the tumor reaches 15 millimeters in any dimension, use 70%ethanol to sterilize the skin and use a 15 scalpel to incise the skin overlying the tumor. Use sterile surgical scissors to dissect the tumor from the surrounding attached soft tissues sharply and place the tumor in one well of a six-well plate containing complete growth medium. Use the scalpel to mince the tumor into appropriately sized fragments and place the fragments into a new container of sterile complete growth medium at room temperature.For cryopreservation, pool multiple fragments in a single cryovial in complete growth medium supplemented with 20%fetal bovine serum and 10%dimethyl sulfoxide and use a commercial cryopreservation system at minus 80 degrees Celsius to gradually freeze the tissue before long-term storage in liquid nitrogen. To preserve tumor fragments for subsequent analysis but not future implantation, snap freeze the samples by liquid nitrogen immersion and store the frozen tumor fragments long term at minus 80 degrees Celsius. For subcutaneous tumor fragment implantation, first bring the tumor fragments suspension to room temperature.Next, confirm a lack of response to pedal reflex in an anesthetized recipient mouse and subcutaneously administer analgesia. To minimize the potential trauma to the skin, use depilating cream to remove the hair on the right knee joint and proximal tibia of the connected hindlimb. Scrub the exposed skin with 70%ethanol, followed by alternating chlorhexidine and saline scrubs.While flexing and extending the joint, visualize the proximal tibia as the region just distal to the knee joint and use a 15 scalpel blade to create a three to four millimeter incision at the level of the proximal tibia on the medial aspect of the limb through the skin and subcutaneous tissue to expose the medial cortex of the proximal tibia. To create a small hole in the medial cortex of the proximal tibia, use the tip of a 25 gauge needle to apply gentle pressure while rotating the tip approximately two millimeters distal to the knee joint and equidistant between the cranial and caudal tibial cortexes. When the hole has been created, use sterile forceps or a 27 to 30 gauge needle to insert a minimum of 0.5 cubed millimeter tumor fragments into the medullary cavity of the proximal tibia and use a 27 to 30 gauge needle to manipulate the tumor fragments into the medullary canal.After placing all the fragments, oppose the skin edges with the appropriate material and return the animal to its cage with monitoring until ambulatory. Then evaluate the tibial tumor growth noninvasively by weekly digital radiography, bioluminescence, or fluorescence imaging, and use calipers to measure the limb at the implantation site. Successful engraftment can be documented with advanced imaging.In this representative analysis, the cortical defect created for tumor graft implantation was visible in the proximal tibia one week after implantation. By week two, visible osteolysis and bone remodeling adjacent to the cortical defect could be observed. From weeks two to five, additional progressive bone destruction and the formation of new bone associated with tumor engraftment and growth occurred.Care should be taken while creating a small hole in the proximal tibia. Rely on rotating the tip with gentle to minimal pressure allowing the needle tip to do the work. Following this procedure, tumor graft placement in other bone sites, placement of organoids or tumor cells in the extracellular matrix into the bone defect or molecular and histologic analysis in addition to imaging can be performed.

modeling-primary-bone-tumors-bone-metastasis-with-solid-tumor-graft

Research

JoVE Journal

Cancer Research

Next Generation Sequencing for the Detection of Actionable Mutations in Solid and Liquid Tumors

As our understanding of the driver mutations necessary for initiation and progression of cancers improves, we gain critical information on how specific molecular profiles of a tumor may predict responsiveness to therapeutic agents or provide knowledge about prognosis. At our institution a tumor genotyping program was established as part of routine clinical care, screening both hematologic and solid tumors for a wide spectrum of mutations using two next-generation sequencing (NGS) panels: a custom, 33 gene hematological malignancies panel for use with peripheral blood and bone marrow, and a commercially produced solid tumor panel for use with formalin-fixed paraffin-embedded tissue that targets 47 genes commonly mutated in cancer. Our workflow includes a pathologist review of the biopsy to ensure there is adequate amount of tumor for the assay followed by customized DNA extraction is performed on the specimen. Quality control of the specimen includes steps for quantity, quality and integrity and only after the extracted DNA passes these metrics an amplicon library is generated and sequenced. The resulting data is analyzed through an in-house bioinformatics pipeline and the variants are reviewed and interpreted for pathogenicity. Here we provide a snapshot of the utility of each panel using two clinical cases to provide insight into how a well-designed NGS workflow can contribute to optimizing clinical outcomes.

This manuscript describes clinical protocols for two next-generation sequencing panels. One panel interrogates hematologic malignancies while the other panel targets genes commonly mutated in solid tumors. Molecular classification of driver mutations in human malignancies offers valuable prognostic and predictive information.

As our understanding of the driver mutations necessary for initiation and progression of cancers improves, we gain critical information on how specific ...

Intra-iliac Artery Injection for Efficient and Selective Modeling of Microscopic Bone Metastasis

Intra-iliac artery (IIA) injection is an efficient approach to introduce metastatic lesions of various cancer cells in animals. Compared to the widely used intra-cardiac and intra-tibial injections, IIA injection brings several advantages. First, it can deliver a large quantity of cancer cells specifically to hind limb bones, thereby providing spatiotemporally synchronized early-stage colonization events and allowing robust quantification and swift detection of disseminated tumor cells. Second, it injects cancer cells into the circulation without damaging the local tissues, thereby avoiding inflammatory and wound-healing processes that confound the bone colonization process. Third, IIA injection causes very little metastatic growth in non-bone organs, thereby preventing animals from succumbing to other vital metastases, and allowing continuous monitoring of indolent bone lesions. These advantages are especially useful for the inspection of progression from single cancer cells to multi-cell micrometastases, which has largely been elusive in the past. When combined with cutting-edge approaches of biological imaging and bone histology, IIA injection can be applied to various research purposes related to bone metastases.

This manuscript provides the detailed procedure of intra-iliac artery (IIA) injection, a technique to deliver cancer cells specifically to hind limb tissues including bones to establish experimental bone metastases. Although initially established with breast tumor models, this protocol can be easily extended to other cancer types.

Intra-iliac artery (IIA) injection is an efficient approach to introduce metastatic lesions of various cancer cells in animals. Compared to the widely ...

Dual Effects of Melanoma Cell-derived Factors on Bone Marrow Adipocytes Differentiation

The crosstalk between bone marrow adipocytes and tumor cells may play a critical role in the process of bone metastasis. A variety of methods are available for studying the significant crosstalk; however, a two-dimensional transwell system for coculture remains a classic, reliable, and easy way for this crosstalk study. Here, we present a detailed protocol that shows the coculture of bone marrow adipocytes and melanoma cells. Nevertheless, such a coculture system could not only contribute to the study of cell signal transductions of cancer cells induced by bone marrow adipocytes, but also to the future mechanistic study of bone metastasis which may reveal new therapeutic targets for bone metastasis.

Here, we present a reliable and straightforward two-dimensional (2D) coculture system for studying the interaction between tumor cells and bone marrow adipocytes, which reveals a dual effect of melanoma cell-derived factors on the bone marrow adipocytes differentiation and also poses a classic method for the mechanistic study of bone metastasis.

The crosstalk between bone marrow adipocytes and tumor cells may play a critical role in the process of bone metastasis. A variety of methods are ...

Measuring Bone Remodeling and Recreating the Tumor-Bone Microenvironment Using Calvaria Co-culture and Histomorphometry

Bone is a connective tissue constituted of osteoblasts, osteocytes, and osteoclasts and a mineralized extracellular matrix, which gives it its strength and flexibility and allows it to fulfill its functions. Bone is continuously exposed to a variety of stimuli, which in pathological conditions can deregulate bone remodeling. To study bone biology and diseases and evaluate potential therapeutic agents, it has been necessary to develop in vitro and in vivo models.
This manuscript describes the dissection process and culture conditions of calvarias isolated from neonatal mice to study bone formation and the bone tumor microenvironment. In contrast to in vitro and in vivo models, this ex vivo model allows preservation of the three-dimensional environment of the tissue as well as the cellular diversity of the bone while culturing under defined conditions to simulate the desired microenvironment. Therefore, it is possible to investigate bone remodeling and its mechanisms, as well as the interactions with other cell types, such as the interactions between cancer cells and bone.
The assays reported here use calvarias from 5-7 day old BALB/C mice. The hemi-calvarias obtained are cultured in the presence of insulin, breast cancer cells (MDA-MB-231), or conditioned medium from breast cancer cell cultures. After analysis, it was established that insulin induced new bone formation, while cancer cells and their conditioned medium induced bone resorption. The calvarial model has been successfully used in basic and applied research to study bone development and cancer-induced bone diseases. Overall, it is an excellent option for an easy, informative, and low-cost assay.

The ex vivo culture of bone explants can be a valuable tool for the study of bone physiology and the potential evaluation of drugs in bone remodeling and bone diseases. The presented protocol describes the preparation and culture of calvarias isolated from newborn mice skulls, as well as its applications.

Bone is a connective tissue constituted of osteoblasts, osteocytes, and osteoclasts and a mineralized extracellular matrix, which gives it its strength ...

Three-Dimensional Bone Extracellular Matrix Model for Osteosarcoma

Osteosarcoma (OS) is the most common and a highly aggressive primary bone tumor. It is characterized with anatomic and histologic variations along with diagnostic or prognostic difficulties. OS comprises genotypically and phenotypically heterogeneous cancer cells. Bone microenvironment elements are proved to account for tumor heterogeneity and disease progression. Bone extracellular matrix (BEM) retains the microstructural matrices and biochemical components of native extracellular matrix. This tissue-specific niche provides a favorable and long-term scaffold for OS cell seeding and proliferation. This article provides a protocol for the preparation of BEM model and its further experimental application. OS cells can grow and differentiate into multiple phenotypes consistent with the histopathological complexity of OS clinical specimens. The model also allows visualization of diverse morphologies and their association with genetic alterations and underlying regulatory mechanisms. As homologous to human OS, this BEM-OS model can be developed and applied to the pathology and clinical research of OS.

The bone extracellular matrix (BEM) model for osteosarcoma (OS) is well established and shown here. It can be used as a suitable scaffold for mimicking primary tumor growth in vitro and providing an ideal model for studying the histologic and cytogenic heterogeneity of OS.

Osteosarcoma (OS) is the most common and a highly aggressive primary bone tumor. It is characterized with anatomic and histologic variations along with ...

Micromanipulation of Circulating Tumor Cells for Downstream Molecular Analysis and Metastatic Potential Assessment

Blood-borne metastasis accounts for&#160;most cancer-related deaths and involves circulating tumor cells (CTCs) that are successful in establishing new tumors at distant sites. CTCs are found in the bloodstream of patients as single cells (single CTCs) or as multicellular aggregates (CTC clusters and CTC-white blood cell clusters), with the latter displaying a higher metastatic ability. Beyond enumeration, phenotypic and molecular analysis is extraordinarily important to dissect CTC biology and to identify actionable vulnerabilities. Here, we provide a detailed description of a workflow that includes CTC immunostaining and micromanipulation, ex vivo culture to assess&#160;proliferative and survival capabilities of individual cells, and in vivo metastasis-formation assays. Additionally, we provide a protocol to achieve the dissociation of CTC clusters into individual cells and the investigation of intra-cluster heterogeneity. With these approaches, for instance, we precisely quantify survival and proliferative potential of single CTCs and individual cells within CTC clusters, leading us to the observation that cells within clusters display better survival and proliferation in ex vivo cultures compared to single CTCs. Overall, our workflow offers a platform to dissect the characteristics of CTCs at the single cell level, aiming towards the identification of metastasis-relevant pathways and a better understanding of CTC biology.

Here, we present an integrated workflow to identify phenotypic and molecular features that characterize circulating tumor cells (CTCs). We combine live immunostaining and robotic micromanipulation of single and clustered CTCs with single cell-based techniques for downstream analysis and assessment of metastasis-seeding ability.

Blood-borne metastasis accounts for&#160;most cancer-related deaths and involves circulating tumor cells (CTCs) that are successful in establishing new ...

Establishment and Analysis of Three-Dimensional (3D) Organoids Derived from Patient Prostate Cancer Bone Metastasis Specimens and their Xenografts

Three-dimensional (3D) culture of organoids from tumor specimens of human patients and patient-derived xenograft (PDX) models of prostate cancer, referred to as patient-derived organoids (PDO), are an invaluable resource for studying the mechanism of tumorigenesis and metastasis of prostate cancer. Their main advantage is that they maintain the distinctive genomic and functional heterogeneity of the original tissue compared to conventional cell lines that do not. Furthermore, 3D cultures of PDO can be used to predict the effects of drug treatment on individual patients and are a step towards personalized medicine. Despite these advantages, few groups routinely use this method in part because of the extensive optimization of PDO culture conditions that may be required for different patient samples. We previously demonstrated that our prostate cancer bone metastasis PDX model, PCSD1, recapitulated the resistance of the donor patient&rsquo;s bone metastasis to anti-androgen therapy. We used PCSD1 3D organoids to characterize further the mechanisms of anti-androgen resistance. Following an overview of currently published studies of PDX and PDO models, we describe a step-by-step protocol for 3D culture of PDO using domed or floating basement membrane (e.g., Matrigel) spheres in optimized culture conditions. In vivo stitch imaging and cell processing for histology are also described. This protocol can be further optimized for other applications including western blot, co-culture, etc. and can be used to explore characteristics of 3D cultured PDO pertaining to drug resistance, tumorigenesis, metastasis and therapeutics.

Establishment and Analysis of Three-Dimensional 3D Organoids Derived from Patient Prostate Cancer Bone Metastasis Specimens and their Xenografts

Three-dimensional cultures of patient BMPC specimens and xenografts of bone metastatic prostate cancer maintain the functional heterogeneity of their original tumors resulting in cysts, spheroids and complex, tumor-like organoids. This manuscript provides an optimization strategy and protocol for 3D culture of heterogeneous patient derived samples and their analysis using IFC.

Three-dimensional (3D) culture of organoids from tumor specimens of human patients and patient-derived xenograft (PDX) models of prostate cancer, referred ...

Machine Learning Algorithms for Early Detection of Bone Metastases in an Experimental Rat Model

Machine learning (ML) algorithms permit the integration of different features into a model to perform classification or regression tasks with an accuracy exceeding its constituents. This protocol describes the development of an ML algorithm to predict the growth of breast cancer bone macrometastases in a rat model before any abnormalities are observable with standard imaging methods. Such an algorithm can facilitate the detection of early metastatic disease (i.e., micrometastasis) that is regularly missed during staging examinations.
The applied metastasis model is site-specific, meaning that the rats develop metastases exclusively in their right hind leg. The model&#8217;s tumor-take rate is 60%&#8211;80%, with macrometastases becoming visible in magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) in a subset of animals 30 days after induction, whereas a second subset of animals exhibit no tumor growth.
Starting from image examinations acquired at an earlier time point, this protocol describes the extraction of features that indicate tissue vascularization detected by MRI, glucose metabolism by PET/CT, and the subsequent determination of the most relevant features for the prediction of macrometastatic disease. These features are then fed into a model-averaged neural network (avNNet) to classify the animals into one of two groups: one that will develop metastases and the other that will not develop any tumors. The protocol also describes the calculation of standard diagnostic parameters, such as overall accuracy, sensitivity, specificity, negative/positive predictive values, likelihood ratios, and the development of a receiver operating characteristic. An advantage of the proposed protocol is its flexibility, as it can be easily adapted to train a plethora of different ML algorithms with adjustable combinations of an unlimited number of features. Moreover, it can be used to analyze different problems in oncology, infection, and inflammation.

This protocol was designed to train a machine learning algorithm to use a combination of imaging parameters derived from magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) in a rat model of breast cancer bone metastases to detect early metastatic disease and predict subsequent progression to macrometastases.

Machine learning (ML) algorithms permit the integration of different features into a model to perform classification or regression tasks with an accuracy ...

Intra-Cardiac Injection of Human Prostate Cancer Cells to Create a Bone Metastasis Xenograft Mouse Model

As the most common male malignancy, prostate cancer (PC) ranks second in mortality, primarily due to a 65%-75% bone metastasis rate. Therefore, it is essential to understand the process and related mechanisms of prostate cancer bone metastasis for developing new therapeutics. For this, an animal model of bone metastasis is an essential tool. Here, we report detailed procedures to generate a bone metastasis mouse model via intra-cardiac injection of prostate cancer cells. A bioluminescence imaging system can determine whether prostate cancer cells have been accurately injected into the heart and monitor cancer cell metastasis since it has great advantages in monitoring metastatic lesion development. This model replicates the natural development of disseminated cancer cells to form micro-metastases in the bone and imitates the pathological process of prostate cancer bone metastasis. It provides an effective tool for further exploration of the molecular mechanisms and the in vivo therapeutic effects of this disease.

Here, we present a protocol for the intra-cardiac injection of human prostate cancer cells to generate a mouse model with bone metastasis lesions.

As the most common male malignancy, prostate cancer (PC) ranks second in mortality, primarily due to a 65%-75% bone metastasis rate. Therefore, it is ...

Isolation and Characterization of Bone Marrow Microenvironment in Myeloid Neoplasms

Identifying Bone Marrow Microenvironmental Populations in Myelodysplastic Syndrome and Acute Myeloid Leukemia

The bone marrow microenvironment consists of distinct cell populations, such as mesenchymal stromal cells, endothelial cells, osteolineage cells, and fibroblasts, which provide support for hematopoietic stem cells (HSCs). In addition to supporting normal HSCs, the bone marrow microenvironment also plays a role in the development of hematopoietic stem cell disorders, such as myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). MDS-associated mutations in HSCs lead to a block in differentiation and progressive bone marrow failure, especially in the elderly. MDS can often progress to therapy-resistant AML, a disease characterized by a rapid accumulation of immature myeloid blasts. The bone marrow microenvironment is known to be altered in patients with these myeloid neoplasms. Here, a comprehensive protocol to isolate and phenotypically characterize bone marrow microenvironmental cells from murine models of myelodysplastic syndrome and acute myeloid leukemia is described. Isolating and characterizing changes in the bone marrow niche populations can help determine their role in disease initiation and progression and may lead to the development of novel therapeutics targeting cancer-promoting alterations in the bone marrow stromal populations.

Author Spotlight: Analyzing Bone Marrow Microenvironment in Murine Hematological Malignancies 

Here a detailed protocol to isolate and characterize bone marrow microenvironmental populations from murine models of myelodysplastic syndromes and acute myeloid leukemia is presented. This technique identifies changes in the non-hematopoietic bone marrow niche, including the endothelial and mesenchymal stromal cells, with disease progression.

The bone marrow microenvironment consists of distinct cell populations, such as mesenchymal stromal cells, endothelial cells, osteolineage cells, and ...