This work was supported by a grant R01 CA240323 (S.Z.) from the National Cancer Institute; a grant W81XWH-17-1-0498 (S.Z.) from the United States Department of Defense (DoD); a V Scholar award from the V Foundation for Cancer Research (S.Z.) and a Platform Grant from the Mayo Center for Biomedical Discovery (S.Z.); and supports from the Mayo Clinic Cancer Center and Center for Individualized Medicine (S.Z.).

<ol>
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C., Hynes, R. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intravital+imaging+of+metastasis+in+adult+Zebrafish.">Intravital imaging of metastasis in adult Zebrafish.</a> BMC Cancer. 17 (1), 660 (2017).</li><li>Kim, I. 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=Microenvironment-derived+factors+driving+metastatic+plasticity+in+melanoma.">Microenvironment-derived factors driving metastatic plasticity in melanoma.</a> Nature Communications. 8, 14343 (2017).</li><li>Zhu, 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=Activated+ALK+collaborates+with+MYCN+in+neuroblastoma+pathogenesis.">Activated ALK collaborates with MYCN in neuroblastoma pathogenesis.</a> Cancer Cell. 21 (3), 362-373 (2012).</li><li>Maris, J. M., Hogarty, M. D., Bagatell, R., Cohn, S. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuroblastoma.">Neuroblastoma.</a> Lancet. 369 (9579), 2106-2120 (2007).</li><li>Park, J. 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=Children's+oncology+group's+2013+blueprint+for+research:+neuroblastoma.">Children's oncology group's 2013 blueprint for research: neuroblastoma.</a> Pediatric Blood and Cancer. 60 (6), 985-993 (2013).</li><li>Hoehner, J. 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=A+developmental+model+of+neuroblastoma:+differentiating+stroma-poor+tumors'+progress+along+an+extra-adrenal+chromaffin+lineage.">A developmental model of neuroblastoma: differentiating stroma-poor tumors' progress along an extra-adrenal chromaffin lineage.</a> Laboratory Investigation: A Journal of Technical Methods and Pathology. 75 (5), 659-675 (1996).</li><li>Tsubota, S., Kadomatsu, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Origin+and+initiation+mechanisms+of+neuroblastoma.">Origin and initiation mechanisms of neuroblastoma.</a> Cell and Tissue Research. 372 (2), 211-221 (2018).</li><li>Tolbert, V. P., Matthay, K. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuroblastoma:+Clinical+and+biological+approach+to+risk+stratification+and+treatment.">Neuroblastoma: Clinical and biological approach to risk stratification and treatment.</a> Cell and Tissue Research. 372 (2), 195-209 (2018).</li><li>Maris, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+advances+in+neuroblastoma.">Recent advances in neuroblastoma.</a> New England Journal of Medicine. 362 (23), 2202-2211 (2010).</li><li>Zhu, 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=LMO1+Synergizes+with+MYCN+to+promote+neuroblastoma+initiation+and+metastasis.">LMO1 Synergizes with MYCN to promote neuroblastoma initiation and metastasis.</a> Cancer Cell. 32, 310-323 (2017).</li><li>Patton, E. E., Zon, L. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+art+and+design+of+genetic+screens:+zebrafish.">The art and design of genetic screens: zebrafish.</a> Nature Reviews Genetics. 2 (12), 956-966 (2001).</li><li>Lieschke, G. J., Currie, P. D. <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+human+disease:+zebrafish+swim+into+view.">Animal models of human disease: zebrafish swim into view.</a> Nature Reviews Genetics. 8 (5), 353-367 (2007).</li><li>Tao, 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=LIN28B+regulates+transcription+and+potentiates+MYCN-induced+neuroblastoma+through+binding+to+ZNF143+at+target+gene+promotors.">LIN28B regulates transcription and potentiates MYCN-induced neuroblastoma through binding to ZNF143 at target gene promotors.</a> Proceedings of the National Academy of Sciences of the United States of America. 117 (28), 16516-16526 (2020).</li><li>Ung, C. Y., Guo, F., Zhang, X., Zhu, Z., Zhu, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mosaic+zebrafish+transgenesis+for+functional+genomic+analysis+of+candidate+cooperative+genes+in+tumor+pathogenesis.">Mosaic zebrafish transgenesis for functional genomic analysis of candidate cooperative genes in tumor pathogenesis.</a> Journal of Visualized Experiments. (97), e52567 (2015).</li><li>Zhang, 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=Critical+role+for+GAB2+in+neuroblastoma+pathogenesis+through+the+promotion+of+SHP2/MYCN+cooperation.">Critical role for GAB2 in neuroblastoma pathogenesis through the promotion of SHP2/MYCN cooperation.</a> Cell Reports. 18 (12), 2932-2942 (2017).</li><li>Zimmerman, M. W., 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=MYC+drives+a+subset+of+high-risk+pediatric+neuroblastomas+and+is+activated+through+mechanisms+including+enhancer+hijacking+and+focal+enhancer+amplification.">MYC drives a subset of high-risk pediatric neuroblastomas and is activated through mechanisms including enhancer hijacking and focal enhancer amplification.</a> Cancer Discovery. 8 (3), 320-335 (2018).</li><li>Koach, 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=Drugging+MYCN+oncogenic+signaling+through+the+MYCN-PA2G4+binding+interface.">Drugging MYCN oncogenic signaling through the MYCN-PA2G4 binding interface.</a> Cancer Research. 79 (21), 5652-5667 (2019).</li><li>Kimmel, C. B., Ballard, W. W., Kimmel, S. R., Ullmann, B., Schilling, 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=Stages+of+embryonic+development+of+the+zebrafish.">Stages of embryonic development of the zebrafish.</a> Developmental Dynamics. 203 (3), 253-310 (1995).</li><li>DuBois, S. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Metastatic+sites+in+stage+IV+and+IVS+neuroblastoma+correlate+with+age,+tumor+biology,+and+survival.">Metastatic sites in stage IV and IVS neuroblastoma correlate with age, tumor biology, and survival.</a> Journal of pediatric hematology/oncology. 21 (3), 181-189 (1999).</li><li>Wattrus, S. J., Zon, L. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stem+cell+safe+harbor:+The+hematopoietic+stem+cell+niche+in+zebrafish.">Stem cell safe harbor: The hematopoietic stem cell niche in zebrafish.</a> Blood Advances. 2 (21), 3063-3069 (2018).</li><li>Menke, A. L., Spitsbergen, J. M., Wolterbeek, A. P., Woutersen, 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=Normal+anatomy+and+histology+of+the+adult+zebrafish.">Normal anatomy and histology of the adult zebrafish.</a> Toxicologic Pathology. 39 (5), 759-775 (2011).</li><li>Renshaw, S. A., Trede, N. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+model+450+million+years+in+the+making:+Zebrafish+and+vertebrate+immunity.">A model 450 million years in the making: Zebrafish and vertebrate immunity.</a> Disease Models and Mechanisms. 5 (1), 38-47 (2012).</li><li>Junqueira, L. C., Cossermelli, W., Brentani, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+staining+of+collagens+type+I,+II+and+III+by+Sirius+Red+and+polarization+microscopy.">Differential staining of collagens type I, II and III by Sirius Red and polarization microscopy.</a> Archivum histologicum Japonicum (Nihon Soshikigaku Kiroku). 41 (3), 267-274 (1978).</li><li>Sweat, F., Puchtler, H., Rosenthal, S. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sirius+red+F3BA+as+a+stain+for+connective+tissue.">Sirius red F3BA as a stain for connective tissue.</a> Archives of Pathology. 78, 69-72 (1964).</li><li>Ignatius, M. S., Hayes, M., Langenau, D. M. <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+cancer+in+zebrafish.">In vivo imaging of cancer in zebrafish.</a> Advances in Experimental Medicine and Biology. 916, 219-237 (2016).</li><li>Howe, C. 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=The+zebrafish+reference+genome+sequence+and+its+relationship+to+the+human+genome.">The zebrafish reference genome sequence and its relationship to the human genome.</a> Nature. 496 (7446), 498-503 (2013).</li><li>Fazio, M., Ablain, J., Chuan, Y., Langenau, D. M., Zon, L. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Zebrafish+patient+avatars+in+cancer+biology+and+precision+cancer+therapy.">Zebrafish patient avatars in cancer biology and precision cancer therapy.</a> Nature Reviews Cancer. 20 (5), 263-273 (2020).</li><li>Yoganantharjah, P., Gibert, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Use+of+the+zebrafish+model+to+aid+in+drug+discovery+and+target+validation.">The Use of the zebrafish model to aid in drug discovery and target validation.</a> Current Topics in Medicinal Chemistry. 17 (18), 2041-2055 (2018).</li><li>Ignatius, M. 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=In+vivo+imaging+of+tumor-propagating+cells,+regional+tumor+heterogeneity,+and+dynamic+cell+movements+in+embryonal+rhabdomyosarcoma.">In vivo imaging of tumor-propagating cells, regional tumor heterogeneity, and dynamic cell movements in embryonal rhabdomyosarcoma.</a> Cancer Cell. 21 (5), 680-693 (2012).</li><li>Stoletov, K., Montel, V., Lester, R. D., Gonias, S. L., Klemke, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-resolution+imaging+of+the+dynamic+tumor+cell+vascular+interface+in+transparent+zebrafish.">High-resolution imaging of the dynamic tumor cell vascular interface in transparent zebrafish.</a> Proceedings of the National Academy of Sciences of the United States of America. 104 (44), 17406-17411 (2007).</li><li>Ahmed, 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=Neuroblastoma+with+orbital+metastasis:+ophthalmic+presentation+and+role+of+ophthalmologists.">Neuroblastoma with orbital metastasis: ophthalmic presentation and role of ophthalmologists.</a> Eye. 20 (4), 466-470 (2006).</li><li>Papaioannou, G., McHugh, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuroblastoma+in+childhood:+review+and+radiological+findings.">Neuroblastoma in childhood: review and radiological findings.</a> Cancer Imaging Society. 5 (1), 116-127 (2005).</li><li>Langenau, D. M., 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=Co-injection+strategies+to+modify+radiation+sensitivity+and+tumor+initiation+in+transgenic+Zebrafish.">Co-injection strategies to modify radiation sensitivity and tumor initiation in transgenic Zebrafish.</a> Oncogene. 27 (30), 4242-4248 (2008).</li><li>Amores, A., 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=Zebrafish+hox+clusters+and+vertebrate+genome+evolution.">Zebrafish hox clusters and vertebrate genome evolution.</a> Science. 282 (5394), 1711-1714 (1998).</li><li>Postlethwait, J. 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The authors declare that they have no competing financial interests.

Zebrafish has been commonly used in research for the past few decades, especially in cancer research, for obvious reasons, such as its ease of maintenance, robust reproduction, and clear advantages for in vivo imaging1,28. The zebrafish model can be easily manipulated embryonically due to their external fertilization and development, which complements well to mammalian model organisms, such as rats and mice, for large-scale genetic studies<sup class="xre...

Zebrafish has been widely used and applied to several areas of research, especially in cancer. This model provides many advantages-such as its robust reproduction, cost-effective maintenance, and versatile visualization of tumor growth and metastasis-all of which make zebrafish a powerful tool to study and investigate the cellular and molecular bases of tumorigenesis and metastasis. New techniques for large-scale genome mapping, transgenesis, genes overexpression or knockout, cell transplantation, and chemical screens have immensely augmented the power of the zebrafish model1. During the past few years, many zebrafish lines have been developed to study tumorigenesis and metastasis of a variety of human cancers, including but not limited to leukemia, melanoma, rhabdomyosarcoma, and hepatocellular carcinoma2,3,4,5. Additionally, the first zebrafish model of neuroblastoma (NB) was generated by overexpressing MYCN, an oncogene, in the peripheral sympathetic nervous system (PSNS) under control of the dopamine-beta-hydroxylase (d&#946;h) promoter. With this model, it was further demonstrated that activated ALK can synergize with MYCN to accelerate tumor onset and increase tumor penetrance in vivo6.
NB is derived from the sympathoadrenal lineage of the neural crest cells, and is a highly metastatic cancer in children7. It is responsible for 10% of pediatric cancer-related deaths8. Widely metastasized at diagnosis, NB can be clinically presented as tumors primarily originating along the chain of the sympathetic ganglia and the adrenal medulla of PSNS9,10. MYCN amplification is commonly associated with poor outcomes in NB patients11,12. Moreover, LMO1 has been identified as a critical NB susceptibility gene in high-risk cases13,14. Studies found that the transgenic coexpression of MYCN and LMO1 in the PSNS of the zebrafish model not only promotes earlier onset of NB, but also induces widespread metastasis to the tissues and organs that are similar to sites commonly seen in patients with high-risk NB13. Very recently, another metastatic phenotype of NB has also been observed in a newer zebrafish model of NB, in which both MYCN and Lin28B, encoding an RNA binding protein, are overexpressed under control of the d&#946;h promoter16.
The stable transgenic approach in zebrafish is often used to study whether overexpression of a gene of interest could contribute to the normal development and disease pathogenesis14,15. This technique has been successfully used to demonstrate the importance of multiple genes and pathways to NB tumorigenesis6,16,17,18,19,20. This paper will introduce how the transgenic fish line that overexpresses both MYCN and LMO1 in the PSNS was created and how it was demonstrated that the cooperation of these two oncogenes accelerate the onset of NB tumorigenesis and metastasis13. First, the transgenic line that overexpresses EGFP-MYCN under control of the d&#946;h promoter (designated MYCN line) was developed by injecting the d&#946;h-EGFP-MYCN construct into one-cell stage of wild-type (WT) AB embryos, as previously described6,17. A separate transgenic line that overexpresses LMO1 in the PSNS (designated LMO1 line) was developed by coinjecting two DNA constructs, d&#946;h-LMO1 and d&#946;h-mCherry, into WT embryos at the one-cell stage13. It has been previously demonstrated that coinjected double DNA constructs can be cointegrated into the fish genome; therefore, LMO1 and mCherry are coexpressed in the PSNS cells of the transgenic animals. Once the injected F0 embryos reached sexual maturity, they were then out-crossed with WT fish for the identification of positive fish with transgene(s) integration. Briefly, the F1 offspring were first screened by fluorescent microscopy for mCherry expression in the PSNS cells. The germline integration of LMO1 in mCherry-positive fish was further confirmed by genomic PCR and sequencing. After successful identification of each transgenic line, the progeny of heterozygous MYCN and LMO1 transgenic fish were interbred to generate a compound fish line expressing both MYCN and LMO1 (designated MYCN;LMO1 line). Tumor-bearing MYCN;LMO1 fish were monitored by fluorescent microscopy biweekly for the evidence of metastatic tumors in the regions distant to the primary site, interrenal gland region (IRG, zebrafish equivalent of human adrenal gland)13. To confirm the metastasis of tumors in MYCN;LMO1 fish, histological and immunohistochemical analyses were applied.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>3,3&#8217;-Diaminobenzidine (DAB) Vector Kit</td>
			<td>Vector</td>
			<td>SK-4100</td>
			<td></td>
		</tr>
		<tr>
			<td>Acetic Acid</td>
			<td>Fisher Scientific / Acros Organic</td>
			<td>64-19-7</td>
			<td></td>
		</tr>
		<tr>
			<td>Agarose GP2</td>
			<td>Midwest Scientific</td>
			<td>009012-36-6</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-Tyrosine Hydroxylase (TH) Antibody</td>
			<td>Pel-Freez</td>
			<td>P40101</td>
			<td></td>
		</tr>
		<tr>
			<td>Avidin/Biotin Blocking Kit</td>
			<td>Vector</td>
			<td>SP-2001</td>
			<td></td>
		</tr>
		<tr>
			<td>BOND Intense R Detection</td>
			<td>Leica Biosystems</td>
			<td>DS9263</td>
			<td></td>
		</tr>
		<tr>
			<td>BOND primary antibody diluent</td>
			<td>Leica Biosystems Newcastle, Ltd.</td>
			<td>AR9352</td>
			<td></td>
		</tr>
		<tr>
			<td>BOND-MAX IHC instrument</td>
			<td>Leica Biosystems Newcastle, Ltd.</td>
			<td>N/A</td>
			<td>fully automated IHC staining system</td>
		</tr>
		<tr>
			<td>CH211-270H11 BAC clone</td>
			<td>BACPAC resources center (BRFC)</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Compound microscope equipped with DP71 camera</td>
			<td>Olympus</td>
			<td>AX70</td>
			<td></td>
		</tr>
		<tr>
			<td>Cytoseal XYL (xylene based mounting medium)</td>
			<td>Richard-Allan Scientific</td>
			<td>8312-4</td>
			<td></td>
		</tr>
		<tr>
			<td>Eosin</td>
			<td>Leica</td>
			<td>3801601</td>
			<td>ready-to-use (no preparation needed)</td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>Carolina</td>
			<td>86-1263</td>
			<td></td>
		</tr>
		<tr>
			<td>Expand Long Template PCR System</td>
			<td>Roche Applied Science, IN</td>
			<td>11681834001</td>
			<td></td>
		</tr>
		<tr>
			<td>Gateway BP Clonase II enzyme mix</td>
			<td>Invitrogen, CA</td>
			<td>11789-020</td>
			<td></td>
		</tr>
		<tr>
			<td>Gateway LR Clonase II enzyme mix</td>
			<td>Invitrogen, CA</td>
			<td>11791-100</td>
			<td></td>
		</tr>
		<tr>
			<td>Goat anti-Rb secondary antibody (Biotinylated)</td>
			<td>Dako</td>
			<td>E0432</td>
			<td></td>
		</tr>
		<tr>
			<td>Hematoxylin Solution, Harris Modified</td>
			<td>Sigma Aldrich Chemical Company Inc. / SAFC</td>
			<td>HHS-32-1L</td>
			<td></td>
		</tr>
		<tr>
			<td>HRP Avidin D</td>
			<td>Vector</td>
			<td>A-2004</td>
			<td></td>
		</tr>
		<tr>
			<td>Hydrochloric Acid</td>
			<td>Aqua Solutions</td>
			<td>4360-1L</td>
			<td></td>
		</tr>
		<tr>
			<td>Hydrogen Peroxide, 3%</td>
			<td>Fisher Scientific</td>
			<td>H324-500</td>
			<td></td>
		</tr>
		<tr>
			<td>I-SceI enzyme</td>
			<td>New England Biolabs, MA</td>
			<td>R0694L</td>
			<td></td>
		</tr>
		<tr>
			<td>Kanamycin sulfate</td>
			<td>Teknova, Inc.</td>
			<td>K2150</td>
			<td></td>
		</tr>
		<tr>
			<td>Kimberly-Clark Professional Kimtech Science Kimwipes</td>
			<td>Fisher Scientific</td>
			<td>34133</td>
			<td></td>
		</tr>
		<tr>
			<td>Lithium Carbonate</td>
			<td>Sigma Aldrich Chemical Company Inc. / SAFC</td>
			<td>554-13-2</td>
			<td></td>
		</tr>
		<tr>
			<td>Microtome for sectioning</td>
			<td>Leica Biosystems</td>
			<td>RM2255</td>
			<td></td>
		</tr>
		<tr>
			<td>One Shot TOP10 Chemically Competent&#160;E. coli</td>
			<td>Invitrogen</td>
			<td>C404006</td>
			<td></td>
		</tr>
		<tr>
			<td>p3E-polyA</td>
			<td>&#160;Dr. Chi-Bin Chien, Univ. of Utah</td>
			<td>N/A</td>
			<td>a generous gift 
			(Please refer to webpage http://tol2kit.genetics.utah.edu/index.php/Main_Page to obtain material, which is freely distrubted as described.)</td>
		</tr>
		<tr>
			<td>Parafin wax</td>
			<td>Surgipath Paraplast</td>
			<td>39603002</td>
			<td>Parrafin to parafin</td>
		</tr>
		<tr>
			<td>Paraformaldehyde</td>
			<td>Alfa Aesar</td>
			<td>A11313</td>
			<td></td>
		</tr>
		<tr>
			<td>pDEST vector (modified destination vector containing I-SceI recognition sites)</td>
			<td>Dr. C. Grabher, Karlsruhe Institute of Technology, Karlsruhe, Germany</td>
			<td>N/A</td>
			<td>a generous gift</td>
		</tr>
		<tr>
			<td>pDONR 221 gateway donor vector</td>
			<td>Thermo Fisher Scientific</td>
			<td>12536-017</td>
			<td></td>
		</tr>
		<tr>
			<td>pDONRP4-P1R donor vector</td>
			<td>&#160;Dr. Chi-Bin Chien, Univ. of Utah</td>
			<td>N/A</td>
			<td>a generous gift</td>
		</tr>
		<tr>
			<td>Phenol red, 0.5%</td>
			<td>Sigma Aldrich</td>
			<td>&#160;P0290</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphate Buffered Saline (PBS), 10X</td>
			<td>BioRad</td>
			<td>1610780</td>
			<td></td>
		</tr>
		<tr>
			<td>Picrosirrius red stain kit</td>
			<td>Polysciences</td>
			<td>24901-250</td>
			<td></td>
		</tr>
		<tr>
			<td>pME-mCherry</td>
			<td>Addgene</td>
			<td>26028</td>
			<td>(DBH construct)</td>
		</tr>
		<tr>
			<td>Proteinase K, recombinant, PCR Grade</td>
			<td>Roche</td>
			<td>21712520</td>
			<td></td>
		</tr>
		<tr>
			<td>QIAprep Spin MiniPrep Kit</td>
			<td>Qiagen</td>
			<td>27104</td>
			<td></td>
		</tr>
		<tr>
			<td>RDO Rapid Decalcifier</td>
			<td>Apex Enginerring</td>
			<td>RDO04</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium Azide (NaN3)</td>
			<td>Sigma Aldrich</td>
			<td>26628-22-8</td>
			<td></td>
		</tr>
		<tr>
			<td>Stereo fluorescence microscope</td>
			<td>Leica</td>
			<td>MZ10F</td>
			<td></td>
		</tr>
		<tr>
			<td>Stereoscopic fluorescence microscope equipped with a digital sight DS-U1 camera for imaging</td>
			<td>Nikon</td>
			<td>SMZ-1500</td>
			<td></td>
		</tr>
		<tr>
			<td>Taq DNA Polymerase</td>
			<td>New England Biolabs, MA</td>
			<td>M0273L</td>
			<td></td>
		</tr>
		<tr>
			<td>Tissue-Tek VIP&#174;&#160;6 AI Vacuum Infiltration Processor</td>
			<td>Sakura</td>
			<td>N/A</td>
			<td>Model #: VIP-6-A1</td>
		</tr>
		<tr>
			<td>Tricaine-S</td>
			<td>Western Chemical Incorporated</td>
			<td>20513</td>
			<td></td>
		</tr>
		<tr>
			<td>Xylene</td>
			<td>Thermo Fisher Scientific</td>
			<td>X3P1GAL</td>
			<td></td>
		</tr>
	</tbody>
</table>

zebrafish model of neuroblastoma metastasis

Zebrafish has emerged as an important animal model to study human diseases, especially cancer. Along with the robust transgenic and genome editing technologies applied in zebrafish modeling, the ease of maintenance, high-yield productivity, and powerful live imaging altogether make the zebrafish a valuable model system to study metastasis and cellular and molecular bases underlying this process in vivo. The first zebrafish neuroblastoma (NB) model of metastasis was developed by overexpressing two oncogenes, MYCN and LMO1, under control of the dopamine-beta-hydroxylase (d&#946;h) promoter. Co-overexpressed MYCN and LMO1 led to the reduced latency and increased penetrance of neuroblastomagenesis, as well as accelerated distant metastasis of tumor cells. This new model reliably reiterates many key features of human metastatic NB, including involvement of clinically relevant and metastasis-associated genetic alterations; natural and spontaneous development of metastasis in vivo; and conserved sites of metastases. Therefore, the zebrafish model possesses unique advantages to dissect the complex process of tumor metastasis in vivo.

To determine whether LMO1 synergizes with MYCN to affect NB pathogenesis, transgenic constructs that drive expression of either LMO1 (d&#946;h:LMO1 and d&#946;h:mCherry) or MYCN (d&#946;h:EGFP-MYCN) in the PSNS cells under control of the d&#946;h promoter were injected into zebrafish embryos13. As illustrated in Figure 1A, after the development of stable transgenic lines and validation of their ge...

Watch this Scientific Journal Video about Zebrafish Model of Neuroblastoma Metastasis at JoVE.com

Zebrafish Model of Neuroblastoma Metastasis

This paper introduces the method of developing, characterizing, and tracking in real-time the tumor metastasis in zebrafish model of neuroblastoma, specifically in the transgenic zebrafish line with overexpression of MYCN and LMO1, which develops metastasis spontaneously.

Zebrafish has emerged as an important animal model to study human diseases, especially cancer. Along with the robust transgenic and genome editing ...

zebrafish-model-of-neuroblastoma-metastasis

Research

JoVE Journal

Cancer Research

2.7K Views.  Mayo Clinic College of Medicine, Mayo Clinic Cancer Center. This paper introduces the method of developing, characterizing, and tracking in real-time the tumor metastasis in zebrafish model of neuroblastoma, specifically in the transgenic zebrafish line with overexpression of MYCN and LMO1, which develops metastasis spontaneously. 

Video: Zebrafish Model of Neuroblastoma Metastasis

Murine Experimental Model of Original Tumor Development and Peritoneal Metastasis via Orthotopic Inoculation with Ovarian Carcinoma Cells

Epithelial ovarian carcinoma (EOC) is associated with a poor prognosis because it shows peritoneal dissemination. To improve the prognosis, it is important to control peritoneal dissemination. However, it is still unclear how tumor cells detach from primary lesions and attach to the mesothelium. The establishment of an appropriate animal model is needed to gain an understanding of the mechanism of peritoneal dissemination in vivo. In the current study, we introduce the process from the local injection of EOC cells into the murine ovarian surface to the development of metastasis, including the peritoneum and distant organs. Female nude mice (BALB/c nu/nu) at 8 weeks of age were used. Under a microscopic field of view, EOC cells (1 x 105 cells/&#181;l of medium-extracellular matrix (ECM)-based hydrogel/unilateral ovary/mouse) were injected into murine ovaries through a retroperitoneal approach from the dorsal flank. This proposed method is a less invasive procedure for the mouse and minimizes damage to the ovary. Here, we describe the methodological steps in the development of the original and metastatic tumor formation of EOC.

Murine Experimental Model of Original Tumor Development and Peritoneal Metastasis via Orthotopic Inoculation with Ovarian Carcinoma Cells

To clarify the multistep process of peritoneal dissemination of ovarian carcinoma, the current study presents a murine experimental model of original tumor development and peritoneal metastasis via orthotopic inoculation with these tumor cells.

Epithelial ovarian carcinoma (EOC) is associated with a poor prognosis because it shows peritoneal dissemination. To improve the prognosis, it is ...

In Vivo Model for Testing Effect of Hypoxia on Tumor Metastasis

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

In Vivo Model for Testing Effect of Hypoxia on Tumor Metastasis

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

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

Advanced Animal Model of Colorectal Metastasis in Liver: Imaging Techniques and Properties of Metastatic Clones

Patients with a limited number of hepatic metastases and slow rates of progression can be successfully treated with local treatment approaches1,2. However, little is known about the heterogeneity of liver metastases, and animal models capable of evaluating the development of individual metastatic colonies are needed. Here, we present an advanced model of hepatic metastases that provides the ability to quantitatively visualize the development of individual tumor clones in the liver and estimate their growth kinetics and colonization efficiency. We generated a panel of monoclonal derivatives of HCT116 human colorectal cancer cells stably labeled with luciferase and tdTomato and possessing different growth properties. With a splenic injection followed by a splenectomy, the majority of these clones are able to generate hepatic metastases, but with different frequencies of colonization and varying growth rates. Using the In Vivo&#160;Imaging System (IVIS), it is possible to visualize and quantify metastasis development with in vivo luminescent and ex vivo fluorescent imaging. In addition, Diffuse Luminescent Imaging Tomography (DLIT) provides a 3D distribution of liver metastases in vivo. Ex vivo fluorescent imaging of harvested livers provides quantitative measurements of individual hepatic metastatic colonies, allowing for the evaluation of the frequency of liver colonization and the growth kinetics of metastases. Since the model is similar to clinically observed liver metastases, it can serve as a modality for detecting genes associated with liver metastasis and for testing potential ablative or adjuvant treatments for liver metastatic disease.

The ability of metastatic clones to colonize distant sites depends on their proliferation capacity and/or their ability to survive in the host microenvironment without significant proliferation. Here, we present an animal model that allows quantitative visualization of both types of liver colonization by metastatic clones.

Patients with a limited number of hepatic metastases and slow rates of progression can be successfully treated with local treatment approaches1,2. ...

Surgical Procedures and Methodology for a Preclinical Murine Model of De Novo Mammary Cancer Metastasis

A rate-limiting aspect of transgenic mouse models of mammary adenocarcinoma is that primary tumor burden in mammary tissue typically defines study end-points. Thus, studies focused on elucidating mechanisms of late-stage de novo metastasis are compromised, as are studies examining efficacy of anti-cancer therapies targeting mediators of metastasis in the adjuvant setting. Numerous murine mammary cancer models have been developed via targeted expression of dominant oncoproteins to mammary epithelial cells yielding models variably mimicking histopathologic and transcriptome-defined breast cancer subtypes common in women1. While much has been learned regarding the biology of mammary carcinogenesis with these models, their utility in identifying molecules regulating growth of late-stage metastasis are compromised as mice are typically euthanized at earlier time points due to significant primary tumor burden. Moreover, since a significant percentage of women diagnosed with breast cancer receive adjuvant therapy after surgical resection of primary tumors and prior to presence of detectable metastatic disease, preclinical models of de novo metastasis are urgently needed as platforms to evaluate new therapies aimed at targeting metastatic foci. To address these deficiencies, we developed a murine model of de novo mammary cancer metastasis, wherein primary mammary tumors are surgically resected, and metastatic foci subsequently develop over a 115 day post-surgical period. This long latency provides a tractable model to identify functionally significant regulators of metastatic progression in mice lacking primary tumor, as well as a model to evaluate preclinical therapeutic efficacy of agents aimed at blocking functionally significant molecules aiding metastatic tumor survival and growth.

Surgical Procedures and Methodology for a Preclinical Murine Model of De Novo Mammary Cancer Metastasis

Pre-clinical models evaluating adjuvant therapy targeting breast cancer metastasis are lacking. To address this, we developed a murine model of de novo pulmonary mammary adenocarcinoma metastasis, wherein therapies administered in the adjuvant setting (post surgical resection of primary tumors) can be evaluated for efficacy in impacting previously seeded pulmonary metastases.

A rate-limiting aspect of transgenic mouse models of mammary adenocarcinoma is that primary tumor burden in mammary tissue typically defines study ...

A Portal Vein Injection Model to Study Liver Metastasis of Breast Cancer

Breast cancer is the leading cause of cancer-related mortality in women worldwide. Liver metastasis is involved in upwards of 30% of cases with breast cancer metastasis, and results in poor outcomes with median survival rates of only 4.8 - 15 months. Current rodent models of breast cancer metastasis, including primary tumor cell xenograft and spontaneous tumor models, rarely metastasize to the liver. Intracardiac and intrasplenic injection models do result in liver metastases, however these models can be confounded by concomitant secondary-site metastasis, or by compromised immunity due to removal of the spleen to avoid tumor growth at the injection site. To address the need for improved liver metastasis models, a murine portal vein injection method that delivers tumor cells firstly and directly to the liver was developed. This model delivers tumor cells to the liver without complications of concurrent metastases in other organs or removal of the spleen. The optimized portal vein protocol employs small injection volumes of 5 - 10 &#956;l, &#8805; 32 gauge needles, and hemostatic gauze at the injection site to control for blood loss. The portal vein injection approach in Balb/c female mice using three syngeneic mammary tumor lines of varying metastatic potential was tested; high-metastatic 4T1 cells, moderate-metastatic D2A1 cells, and low-metastatic D2.OR cells. Concentrations of &#8804; 10,000 cells/injection results in a latency of ~ 20 - 40 days for development of liver metastases with the higher metastatic 4T1 and D2A1 lines, and &#62; 55 days for the less aggressive D2.OR line. This model represents an important tool to study breast cancer metastasis to the liver, and may be applicable to other cancers that frequently metastasize to the liver including colorectal and pancreatic adenocarcinomas.

A surgical procedure was developed to deliver mammary tumor cells to the murine liver via portal vein injection. This model permits investigation of late stages of liver metastasis in a fully immune competent host, including tumor cell extravasation, seeding, survival, and metastatic outgrowth in the liver.

Breast cancer is the leading cause of cancer-related mortality in women worldwide. Liver metastasis is involved in upwards of 30% of cases with breast ...

Acellular and Cellular Lung Model to Study Tumor Metastasis

It is difficult to isolate tumor cells at different points of tumor progression. We created an ex vivo lung model that can show the interaction of tumor cells with a natural matrix and continual flow of nutrients, as well as a model that shows the interaction of tumor cells with normal cellular components and a natural matrix. The acellular ex vivo lung model is created by isolating a rat heart-lung block and removing all the cells using the decellularization process. The right main bronchus is tied off and tumor cells are placed in the trachea by a syringe. The cells move and populate the left lung. The lung is then placed in a bioreactor where the pulmonary artery receives a continual flow of media in a closed circuit. The tumor grown on the left lung is the primary tumor. The tumor cells that are isolated in the circulating media are circulating tumor cells and the tumor cells in the right lung are metastatic lesions. The cellular ex vivo lung model is created by skipping the decellularization process. Each model can be used to answer different research questions.

Here, we present a protocol for an ex vivo lung cancer model that mimics the steps of tumor progression and helps to isolate a primary tumor, circulating tumor cells, and metastatic lesions.

It is difficult to isolate tumor cells at different points of tumor progression. We created an ex vivo lung model that can show the interaction of tumor ...

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 ...

Using Computer-based Image Analysis to Improve Quantification of Lung Metastasis in the 4T1 Breast Cancer Model

Breast cancer is a devastating malignancy, accounting for 40,000 female deaths and 30% of new female cancer diagnoses in the United States in 2019 alone. The leading cause of breast cancer related deaths is the metastatic burden. Therefore, preclinical models for breast cancer need to analyze metastatic burden to be clinically relevant. The 4T1 breast cancer model provides a spontaneously-metastasizing, quantifiable mouse model for stage IV human breast cancer. However, most 4T1 protocols quantify the metastatic burden by manually counting stained colonies on tissue culture plates. While this is sufficient for tissues with lower metastatic burden, human error in manual counting causes inconsistent and variable results when plates are confluent and difficult to count. This method offers a computer-based solution to human counting error. Here, we evaluate the protocol using the lung, a highly metastatic tissue in the 4T1 model. Images of methylene blue-stained plates are acquired and uploaded for analysis in Fiji-ImageJ. Fiji-ImageJ then determines the percentage of the selected area of the image that is blue, representing the percentage of the plate with metastatic burden. This computer-based approach offers more consistent and expeditious results than manual counting or histopathological evaluation for highly metastatic tissues. The consistency of Fiji-ImageJ results depends on the quality of the image. Slight variations in results between images can occur, thus it is recommended that multiple images are taken and results averaged. Despite its minimal limitations, this method is an improvement to quantifying metastatic burden in the lung by offering consistent and rapid results.

We describe a more consistent and expeditious method to quantify lung metastasis in the 4T1 breast cancer model by using Fiji-ImageJ.

Breast cancer is a devastating malignancy, accounting for 40,000 female deaths and 30% of new female cancer diagnoses in the United States in 2019 alone. ...

A Syngeneic Orthotopic Osteosarcoma Sprague Dawley Rat Model with Amputation to Control Metastasis Rate

The most recent advance in the treatment of osteosarcoma (OS) occurred in the 1980s when multi-agent chemotherapy was shown to improve overall survival compared to surgery alone. To address this problem, the aim of the study is to refine a lesser-known model of OS in rats with a comprehensive histologic, imaging, biologic, implantation, and amputation surgical approach that prolongs survival. We used an immunocompetent, outbred Sprague-Dawley (SD), syngeneic rat model with implanted UMR106 OS cell line (originating from a SD rat) with orthotopic tibial tumor implants into 3-week-old male and female rats to model pediatric OS. We found that rats develop reproducible primary and metastatic pulmonary tumors, and that limb amputations at 3 weeks post implantation significantly reduce the incidence of pulmonary metastasis and prevent unexpected deaths. Histologically, the primary and metastatic OSs in rats were very similar to human OS. Using immunohistochemistry methods, the study shows that rat OS are infiltrated with macrophages and T cells. A protein expression survey of OS cells reveals that these tumors express ErbB family kinases. Since these kinases are also highly expressed in most human OSs, this rat model could be used to test ErbB pathway inhibitors for therapy.

Here, a syngeneic orthotopic implantation followed by an amputation procedure of the osteosarcoma with spontaneous pulmonary metastasis that can be used for preclinical investigation of metastasis biology and development of novel therapeutics is described.

The most recent advance in the treatment of osteosarcoma (OS) occurred in the 1980s when multi-agent chemotherapy was shown to improve overall survival ...

The Establishment and Utilization of Patient Derived Xenograft Models of Central Nervous System Metastasis

The development of novel therapies for central nervous system (CNS) metastasis has been hindered by the lack of preclinical models that accurately represent the disease. Patient derived xenograft (PDX) models of CNS metastasis have been shown to better represent the phenotypic and molecular characteristics of the human disease, as well as better reflect the heterogeneity and clonal dynamics of human patient tumors compared to historic cell line models. There are multiple sites that can be used to implant patient-derived tissue when setting up preclinical trials, each with their own advantages and disadvantages, and each suited for studying different aspects of the metastatic cascade. Here, the protocol describes how to establish PDX models and present three different approaches for utilizing CNS metastasis PDX models in pre-clinical studies, discussing each of their applications and limitations. These include flank implantation, orthotopic injection in the brain, and intracardiac injection. Subcutaneous flank implantation is the easiest to monitor and, therefore, most convenient for pre-clinical studies. In addition, metastases to brain and other tissues from flank implantation were observed, indicating that the tumor has undergone multiple steps of metastasis, including intravasation, extravasation, and colonization. Orthotopic injection in the brain is the best option for recapitulating the brain tumor microenvironment and is useful for determining the efficacy of biologics to cross the blood-brain barrier (BBB) but bypasses most steps of the metastatic cascade. Intracardiac injection facilitates metastasis to the brain and is also useful for studying organ tropism. While this method forgoes earlier steps of the metastatic cascade, these cells will still have to survive circulation, extravasate, and colonize. The utility of a PDX model, is therefore, impacted by the route of tumor inoculation and the choice of which one to utilize should be dictated by the scientific question and overall goals of the experiment.

Central nervous system metastasis PDX models represent the phenotypic and molecular characteristics of human metastasis, making them excellent models for preclinical studies. Described here is how to establish PDX models and the inoculation routes that are best used for preclinical studies.