This work was supported by SAAG and SEED grants from the University of the Pacific. We thank Dr. William Chan for granting access to the Odyssey Infrared Imaging 205 System and Dr. John Livesey for granting access to the SpectraMax iD3 plate reader. We thank Dr. Melanie Felmlee for the technical advice on the animal protocols.

The animal study was performed with the approval of the Institutional Animal Care and Use Committee (IACUC) at the University of the Pacific (Animal Protocols 19R10 and 22R10). Eight Male athymic nude mice aged 5-6 weeks, weighing 20-25 g, bred with the referenced Rodent Diet and housed under pathogen-free (SPF) conditions, were used for the present study. Cages, bedding, and drinking water were autoclaved and changed regularly. A schematic of tumor inoculation in mice is shown in Figure 1. See the Table of Materials for details related to all materials and instruments used in this protocol.
1. Establishment of three-dimensional MCS of A549-iRFP cells
<ol>
	<li>Incubate A549-iRFP cells (human lung adenocarcinoma) in a humidified atmosphere with 5% CO2 at 37 &#176;C and grow them in complete growth medium DMEM containing 10% fetal bovine serum, 1% penicillin-streptomycin, and 1 &#181;g/mL puromycin.</li>
	<li>Seed A549-iRFP cells into 96-well ultra-low attachment, round-bottom spheroid microplate at a seeding density of 4,000 cells/well, using 100 &#181;L of complete growth medium supplemented with 0.3% collagen.</li>
	<li>Centrifuge the microplates at 300 &#215; g for 7 min at 4 &#176;C to facilitate the MCS formation. Examine the MCS morphology under a microscope to ensure cell aggregation after centrifugation.</li>
	<li>After 48 h, add 100 &#181;L of complete growth medium to each well to achieve a total volume of 200 &#181;L of growth medium per well.</li>
	<li>Replace 100 &#181;L of growth medium in each well with fresh complete growth medium every other day.</li>
</ol>
2. Characterization of A549-iRFP MCS
<ol>
	<li>Observe and image the MCS morphology using a microscope and estimate the MCS volume by simulation with the referenced software from MATLAB based on the phase-contrast microscope images.
	<ol>
		<li>Open one MCS image in ImageJ software.</li>
		<li>Use Freehand selections to select the edge of the MCS and add it to ROI Manager.</li>
		<li>Click Edit | Selection | Create Mask.</li>
		<li>Click Edit | Invert.</li>
		<li>Click File | Save As | Tiff.</li>
		<li>Open ReViSP software.</li>
		<li>Open the saved TIFF image by clicking Browse.</li>
		<li>Click Start to complete the MCS simulation.</li>
	</ol>
	</li>
	<li>Measure the iRFP fluorescent signal using the infrared imaging system at the 700 nm channel and quantify the fluorescent signal using software (e.g., Image Studio).
	<ol>
		<li>Open Image Studio software.</li>
		<li>In the Channels tab, select 700 and Intensity = 5.</li>
		<li>In the Scan Controls tab, select 84 &#181;m, Medium, 0.0 mm, and Flip Image. Keep everything else as default.</li>
		<li>Click Start to start scanning.</li>
	</ol>
	</li>
	<li>Assess and quantify cell viability using the 3D cell viability assay according to the vendor protocol.</li>
	<li>Assess and quantify cellular protein using the BCA Assay according to the vendor protocol.</li>
</ol>
3. MCS selection for tumor inoculation
NOTE: After MCS are seeded into spheroid microplates and grown for 2-3 weeks with regular growth medium exchange, select MCS with the following appropriate characteristics for tumor inoculation.
<ol>
	<li>Observe the MCS morphology under a microscope and choose MCS with a round shape with overall smooth edges but with 5-10 rough buddings (arrows in Figure 2F) and a diameter within the range of 700-800 &#181;m.</li>
	<li>Measure the iRFP fluorescence (refer to step 2.2) and select the MCS whose fluorescent signals are within one standard deviation of the average.</li>
</ol>
4. Intrapulmonary MCS inoculation
NOTE: Use 70% isopropyl alcohol spray to clean the surgical station and the tools before handling the animals. The surgeon should wear sterile gloves throughout the surgical procedures.
<ol>
	<li>Anesthetize each mouse with an IP injection of 80 mg/kg ketamine and 12 mg/kg xylazine; pinch the mouse feet with forceps to ensure full anesthesia.</li>
	<li>Inject 0.05 mg/kg of buprenorphine hydrochloride subcutaneously to reduce the pain.</li>
	<li>Apply ophthalmic ointment on the eyes to prevent dryness.</li>
	<li>Place the mouse on an infrared heat pad in a dorsal posture and secure the limbs in a stretching position with tapes. 
	NOTE: Provide heat support to the anesthetized mouse throughout the whole surgical procedure.</li>
	<li>Disinfect the back skin by swabbing with alternating rounds of iodine and alcohol, at least three times each.</li>
	<li>Cut a 0.5-1 cm incision using surgical scissors on the left back side (Figure 1B). Carefully use forceps to separate the muscle and fat tissues until the chest wall and lung motion are visible.</li>
	<li>Transfer one selected MCS from a microplate into a glass Petri dish containing ice-cold PBS, using a pipette.</li>
	<li>Attach a 20 G needle onto a 100 &#181;L glass syringe, precool them on ice, and draw 20 &#181;L of a precooled mixture of PBS and Matrigel (1:1 v/v).</li>
	<li>Use the syringe to quickly aspirate one MCS from the Petri dish in a minimum volume of PBS-Matrigel mixture, keeping the MCS in the metal part of the needle. 
	NOTE: Keep a tight grip on the syringe and plunger to prevent the MCS from slipping out of the needle.</li>
	<li>Gently insert the needle vertically between two rib bones to ~3 mm depth and slowly inject all the 20 &#181;L PBS and Matrigel mixture that contains the MCS. 
	NOTE: Avoid excessive force during the insertion to prevent damage to the lung, vasculature, or heart.</li>
	<li>Carefully remove the needle and apply triple antibiotic ointment to the wound.</li>
	<li>Seal the incision with surgical clips, which are to be removed after 2 weeks. 
	NOTE: Do not suture the incision because the suture lines may interfere with fluorescence imaging. The nude mice are able to heal naturally after surgery.</li>
	<li>Place the animal on an infrared heat pad and cover it with laboratory wipes to maintain the body temperature. Monitor the animal for at least 30-60 min until it wakes up and moves properly.</li>
	<li>Inject 0.05 mg/kg of buprenorphine hydrochloride subcutaneously every 8 h for the first 48 h to reduce the pain.</li>
</ol>
5. Postsurgical monitoring
<ol>
	<li>Measure the body weight every 3-4 days.</li>
	<li>Measure the iRFP fluorescent signal from the tumor xenograft every 3-4 days on a small animal imaging system at 700 nm channel in four postures: left, right, dorsal, and ventral, while the mice are kept under anesthesia by isoflurane inhalation (flow rate: 1.5-2 L/min oxygen containing 1.5% isoflurane) over 2-3 min. 
	NOTE: Use 70% isopropyl alcohol spray to clean the small animal imaging system before putting animal onto the imaging station. The surgeon should wear sterile gloves throughout the surgical procedures.</li>
	<li>Quantify the net fluorescent intensity of the xenograft cancer in vivo using software (e.g., Image Studio).
	<ol>
		<li>Use a fixed rectangle (A1, 200 x 125 pixels) as the sampling window for the chest area of the mice.</li>
		<li>Use the free-hand function to trace the shape of the mice within the rectangle (A1) and measure the fluorescent intensity (F1) in area A1.</li>
		<li>Use another smaller rectangle (A2,&#160;25 x 40 pixels) to measure the background fluorescence (F2) of the mice in the thigh area.</li>
		<li>Use equation (1) to calculate the net fluorescent intensity of the xenograft cancer in each mouse: 
		<img alt="Equation 1" src="/files/ftp_upload/66787/66787eq01.jpg" style="margin: auto;" />&#160; &#160; &#160;(1)</li>
	</ol>
	</li>
</ol>

Intrapulmonary Inoculation of Multicellular Spheroids to Model Orthotopic NSCLC

<ol>
	<li>Siegel, R. L., Miller, K. D., Jemal, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cancer+statistics.">Cancer statistics.</a> CA Cancer J Clin. 70 (1), 7-30 (2020).</li><li>Bray, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Global+cancer+statistics+2018:+Globocan+estimates+of+incidence+and+mortality+worldwide+for+36+cancers+in+185+countries.">Global cancer statistics 2018: Globocan estimates of incidence and mortality worldwide for 36 cancers in 185 countries.</a> CA Cancer J Clin. 68 (6), 394-424 (2018).</li><li>Travis, W. D., Brambilla, E., Riely, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+pathologic+classification+of+lung+cancer:+Relevance+for+clinical+practice+and+clinical+trials.">New pathologic classification of lung cancer: Relevance for clinical practice and clinical trials.</a> J Clin Oncol. 31 (8), 992-1001 (2013).</li><li>Ducote, T. 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=Using+artificial+intelligence+to+identify+tumor+microenvironment+heterogeneity+in+non-small+cell+lung+cancers.">Using artificial intelligence to identify tumor microenvironment heterogeneity in non-small cell lung cancers.</a> Lab Invest. 103 (8), 100176 (2023).</li><li>Lim, Z. F., Ma, P. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Emerging+insights+of+tumor+heterogeneity+and+drug+resistance+mechanisms+in+lung+cancer+targeted+therapy.">Emerging insights of tumor heterogeneity and drug resistance mechanisms in lung cancer targeted therapy.</a> J Hematol Oncol. 12 (1), 134 (2019).</li><li>Wang, D. C., Wang, W., Zhu, B., Wang, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lung+cancer+heterogeneity+and+new+strategies+for+drug+therapy.">Lung cancer heterogeneity and new strategies for drug therapy.</a> Annu Rev Pharmacol Toxicol. 58, 531-546 (2018).</li><li>Peterson, J. K., Houghton, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Integrating+pharmacology+and+in+vivo+cancer+models+in+preclinical+and+clinical+drug+development.">Integrating pharmacology and in vivo cancer models in preclinical and clinical drug development.</a> Eur J Cancer. 40 (6), 837-844 (2004).</li><li>Madero-Visbal, R. 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=Bioluminescence+imaging+correlates+with+tumor+progression+in+an+orthotopic+mouse+model+of+lung+cancer.">Bioluminescence imaging correlates with tumor progression in an orthotopic mouse model of lung cancer.</a> Surg Oncol. 21 (1), 23-29 (2012).</li><li>Mclemore, T. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+intrapulmonary+model+for+orthotopic+propagation+of+human+lung+cancers+in+athymic+nude+mice.">Novel intrapulmonary model for orthotopic propagation of human lung cancers in athymic nude mice.</a> Cancer Res. 47 (19), 5132-5140 (1987).</li><li>Zanoni, 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=3d+tumor+spheroid+models+for+in+vitro+therapeutic+screening:+A+systematic+approach+to+enhance+the+biological+relevance+of+data+obtained.">3d tumor spheroid models for in vitro therapeutic screening: A systematic approach to enhance the biological relevance of data obtained.</a> Sci Rep. 6, 19103 (2016).</li><li>Kim, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+tissue+culture+models+in+cancer+biology.">Three-dimensional tissue culture models in cancer biology.</a> Semin Cancer Biol. 15 (5), 365-377 (2005).</li><li>Chaicharoenaudomrung, N., Kunhorm, P., Noisa, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+cell+culture+systems+as+an+in+vitro+platform+for+cancer+and+stem+cell+modeling.">Three-dimensional cell culture systems as an in vitro platform for cancer and stem cell modeling.</a> World J Stem Cells. 11 (12), 1065-1083 (2019).</li><li>Mehta, G., Hsiao, A. Y., Ingram, M., Luker, G. D., Takayama, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Opportunities+and+challenges+for+use+of+tumor+spheroids+as+models+to+test+drug+delivery+and+efficacy.">Opportunities and challenges for use of tumor spheroids as models to test drug delivery and efficacy.</a> J Control Release. 164 (2), 192-204 (2012).</li><li>Huang, B. W., Gao, J. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Application+of+3d+cultured+multicellular+spheroid+tumor+models+in+tumor-targeted+drug+delivery+system+research.">Application of 3d cultured multicellular spheroid tumor models in tumor-targeted drug delivery system research.</a> J Control Release. 270, 246-259 (2018).</li><li>Hirschhaeuser, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multicellular+tumor+spheroids:+An+underestimated+tool+is+catching+up+again.">Multicellular tumor spheroids: An underestimated tool is catching up again.</a> J Biotechnol. 148 (1), 3-15 (2010).</li><li>Sethi, P., 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=3d+tumor+tissue+analogs+and+their+orthotopic+implants+for+understanding+tumor-targeting+of+microenvironment-responsive+nanosized+chemotherapy+and+radiation.">3d tumor tissue analogs and their orthotopic implants for understanding tumor-targeting of microenvironment-responsive nanosized chemotherapy and radiation.</a> Nanomedicine. 11 (8), 2013-2023 (2015).</li><li>Valta, M. P., 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=Spheroid+culture+of+lucap+136+patient-derived+xenograft+enables+versatile+preclinical+models+of+prostate+cancer.">Spheroid culture of lucap 136 patient-derived xenograft enables versatile preclinical models of prostate cancer.</a> Clin Exp Metastasis. 33 (4), 325-337 (2016).</li><li>Huang, Y., 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=Intrapulmonary+inoculation+of+multicellular+spheroids+to+construct+an+orthotopic+lung+cancer+xenograft+model+that+mimics+four+clinical+stages+of+non-small+cell+lung+cancer.">Intrapulmonary inoculation of multicellular spheroids to construct an orthotopic lung cancer xenograft model that mimics four clinical stages of non-small cell lung cancer.</a> J Pharmacol Toxicol Methods. , 106885 (2020).</li><li>Lemjabbar-Alaoui, H., Hassan, O. U., Yang, Y. W., Buchanan, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lung+cancer:+Biology+and+treatment+options.">Lung cancer: Biology and treatment options.</a> Biochim Biophys Acta. 1856 (2), 189-210 (2015).</li><li>Detterbeck, F. C., Boffa, D. J., Kim, A. W., Tanoue, L. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+eighth+edition+lung+cancer+stage+classification.">The eighth edition lung cancer stage classification.</a> Chest. 151 (1), 193-203 (2017).</li></ol>

The authors have no conflicts of interest to declare.

The construction of A549-iRFP MCS is a straightforward and highly reproducible lab procedure and can be translated to MCS formation for multiple cell lines. The MCS generated with the aid of centrifugation and collagen exhibits a more integral and solid-tumor-like structure within 3-4 days. This method ensures the formation of robust spheroids that maintain their integral structure for extended periods, typically 2-3 weeks or even longer until small buddings begin to emerge. By employing centrifugation and collagen, we s...

Among all oncological disorders, lung cancer not only inflicts the highest life loss but also claims the second-highest number of new patients every year in the US1. This devastating malignancy stands as a major obstacle in modern healthcare, urging for a deeper understanding of its intricate biology and more efficacious therapeutic modalities2. Non-small cell lung cancer (NSCLC) accounts for 85% of lung cancer and tends to develop into solid tumors3. One of the foremost challenges in lung cancer is the dynamic and heterogeneous tumor microenvironment, which profoundly influences the cancer&#39;s progression and responses to therapeutic interventions4,5,6. A deeper understanding of the interplay between cancer cells and their microenvironment at different stages of NSCLC calls for refined pathological models that recapitulate the histological features of NSCLC progression.
In this regard, orthotopic animal models emerge as a promising avenue for NSCLC research. Unlike commonly employed subcutaneous xenograft models7, orthotopic models feature cancer cells that are directly inoculated into the organ of origin. For lung cancer, this means implanting cancer cells directly into the lung tissue8,9. Consequently, orthotopic models of lung cancer better mimic the native tumor microenvironment, including the neighboring tissues, vessels, and immune components, thus improving their physiological and clinical relevance.
Three-dimensional multicellular spheroids (MCS) represent another promising approach to recapitulating features of the tumor environment. Most cancers are characterized by their complex tumor microenvironment, including the various cell-cell interactions, the extracellular matrix, and the gradients in oxygen and nutrients10,11. Traditional 2D cell cultures lack the spatial and structural complexity to recapitulate these tumor-specific features12. In contrast, MCS of appropriate size feature a heterogeneous structure with a hypoxic and necrotic core, which recapitulates not only the intratumoral microenvironment but also the physiological barrier against drug penetration, which is a major mechanism of drug resistance in anticancer therapy13,14,15.
Taking advantage of both the orthotopic animal models and the MCS culturing techniques, MCS have been inoculated to immune-compromised mice to successfully construct orthotopic models of breast cancer and prostate cancer16,17. Herein, we report the detailed methodology to construct and characterize a murine orthotopic xenograft model of lung cancer. This method employs the intrapulmonary inoculation of 3D MCS derived from fluorescent human lung cancer cells (A549-iRFP)18. This model offers an exceptional opportunity to observe the in vivo progression of lung cancer through stages that closely parallel the four clinical stages of NSCLC. Furthermore, the xenograft cancer of this model responded to the clinically established antilung cancer drug, cisplatin.

<table><tbody><tr><td>100 &amp;micro;L Glass Syringe</td><td>Hamilton</td><td>Part/REF #80601</td><td></td></tr><tr><td>20 G Needle</td><td>Thermo Fisher Scientific Inc.</td><td>14 826D</td><td></td></tr><tr><td>96-well Ultra-Low-Attachment Spheroid Microplate&amp;nbsp;</td><td>Corning</td><td>15-100-173</td><td></td></tr><tr><td>A549-iRFP</td><td>Imanis Life Sciences&amp;nbsp;</td><td>CL082-STAN</td><td></td></tr><tr><td>AIN-93M Mature Rodent Diet&amp;nbsp;</td><td>Research Diets, Inc.</td><td>D10012M</td><td></td></tr><tr><td>Athymic Nude Mouse</td><td>Charles River Laboratories, Inc.</td><td>Strain Code: 490; homozygous</td><td></td></tr><tr><td>BCA</td><td>Pierce</td><td>23227</td><td></td></tr><tr><td>Buprenorphine Hydrochloride</td><td>Patterson Veterinary</td><td>NDC Number: 42023-179-05</td><td></td></tr><tr><td>CellTiter-Glo 3D Cell Viability Assay</td><td>Promega</td><td>G9683</td><td></td></tr><tr><td>Collagen</td><td>Gibco</td><td>A1064401&amp;nbsp;</td><td></td></tr><tr><td>DMEM</td><td>Corning</td><td>MT10013CV</td><td></td></tr><tr><td>Fetal Bovine Serum (FBS)</td><td>Cytiva HyClone</td><td>SH3039603</td><td></td></tr><tr><td>ImageJ</td><td>Open source tool (https://imagej.net/ij/)</td><td>N/A</td><td></td></tr><tr><td>Image Studio&amp;nbsp;</td><td>LI-COR</td><td>Version 5.2</td><td></td></tr><tr><td>Isoflurane</td><td>Patterson Veterinary</td><td>NDC Number: 17033-0091-25</td><td></td></tr><tr><td>Ketamine</td><td>Patterson Veterinary</td><td>NDC Number: 50989-0161-06</td><td></td></tr><tr><td>Microscope&amp;nbsp;</td><td>Keyence</td><td>Model number: BZ-X710</td><td></td></tr><tr><td>Matrigel</td><td>Corning</td><td>CB-40234</td><td></td></tr><tr><td>Odyssey Infrared Imaging 205 System&amp;nbsp;</td><td>LI-COR</td><td>Model number: 9140</td><td></td></tr><tr><td>PBS</td><td>Corning</td><td>MT21040CV</td><td></td></tr><tr><td>Pearl Trilogy small animal imaging system&amp;nbsp;</td><td>LI-COR</td><td>Model number: 9430</td><td></td></tr><tr><td>Penicillin-Streptomycin&amp;nbsp;</td><td>Corning</td><td>MT30002CI</td><td></td></tr><tr><td>Puromycin</td><td>Thermo Fisher Scientific Inc.</td><td>AAJ67236XF</td><td></td></tr><tr><td>ReViSP software from MATLAB&amp;nbsp;</td><td>Open source tool on Sourceforge (https://sourceforge.net/projects/revisp/)</td><td>N/A</td><td></td></tr><tr><td>Surgical Clips--AutoClip System</td><td>Fine Science Tools</td><td>12020-00</td><td></td></tr><tr><td>Xylazine</td><td>Patterson Veterinary</td><td>NDC Number: 61133-6017-01</td><td></td></tr></tbody></table>

construction of an orthotopic xenograft model of non-small cell lung cancer mimicking disease progression and predicting drug activities

Non-small cell lung cancer (NSCLC) is a highly lethal disease with a complex and heterogeneous tumor microenvironment. Currently, common animal models based on subcutaneous inoculation of cancer cell suspensions do not recapitulate the tumor microenvironment in NSCLC. Herein we describe a murine orthotopic lung cancer xenograft model that employs the intrapulmonary inoculation of three-dimensional multicellular spheroids (MCS). Specifically, fluorescent human NSCLC cells (A549-iRFP) were cultured in low-attachment 96-well microplates with collagen for 3 weeks to form MCS, which were then inoculated intercostally into the left lung of athymic nude mice to establish the orthotopic lung cancer model.
Compared with the original A549 cell line, MCS of the A549-iRFP cell line responded similarly to anticancer drugs. The long-wavelength fluorescent signal of the A549-iRFP cells correlated strongly with common markers of cancer cell growth, including spheroid volume, cell viability, and cellular protein level, thus allowing dynamic monitoring of the cancer growth in vivo by fluorescent imaging. After inoculation into mice, the A549-iRFP MCS xenograft reliably progressed through phases closely resembling the clinical stages of NSCLC, including the expansion of the primary tumor, the emergence of neighboring secondary tumors, and the metastases of cancer cells to the contralateral right lung and remote organs. Moreover, the model responded to the benchmark antilung cancer drug, cisplatin with the anticipated toxicity and slower cancer progression. Therefore, this murine orthotopic xenograft model of NSCLC would serve as a platform to recapitulate the disease&#39;s progression and facilitate the development of potential anticancer drugs.

Characterization of A549-iRFP MCS 
A549-iRFP MCS were successfully cultured in spheroid microplates with the assistance of collagen and centrifugation. When MCS reached a diameter of approximately 500 &#181;m after 1 week, both A549 and A549-iRFP MCS were exposed to a variety of anticancer drugs and formulations for 3 days and then maintained in drug-free growth medium for 4 additional days. The A549-iRFP MCS exhibited a response pattern closely mirroring that of the parent A549 cells. A549 and A549...

Read this Scientific Article Protocol about Construction of An Orthotopic Xenograft Model of Non-small Cell Lung Cancer Mimicking Disease Progression and Predicting Drug Activities at JoVE.com

Author Spotlight: Establishing a Murine Non-Small Cell Lung Cancer Model for Developing Nanoformulations of Anticancer Drugs

This study presents an orthotopic non-small cell lung cancer (NSCLC) model based on intrapulmonary inoculation of multicellular spheroids of fluorescent A549-iRFP cells. The model recapitulates clinical NSCLC stages and responds to cisplatin, according to dynamic in vivo monitoring of long-wavelength fluorescence.

Construction of An Orthotopic Xenograft Model of Non-Small Cell Lung Cancer Mimicking Disease Progression and Predicting Drug Activities

Non-small cell lung cancer (NSCLC) is a highly lethal disease with a complex and heterogeneous tumor microenvironment. Currently, common animal models ...

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832 Views.  University of the Pacific. This study presents an orthotopic non-small cell lung cancer (NSCLC) model based on intrapulmonary inoculation of multicellular spheroids of fluorescent A549-iRFP cells. The model recapitulates clinical NSCLC stages and responds to cisplatin, according to dynamic in vivo monitoring of long-wavelength fluorescence. 

Video: Author Spotlight: Establishing a Murine Non-Small Cell Lung Cancer Model for Developing Nanoformulations of Anticancer Drugs

Development and Maintenance of a Preclinical Patient Derived Tumor Xenograft Model for the Investigation of Novel Anti-Cancer Therapies

Patient derived tumor xenograft (PDTX) models provide a necessary platform in facilitating anti-cancer drug development prior to human trials. Human tumor pieces are injected subcutaneously into athymic nude mice (immunocompromised, T cell deficient) to create a bank of tumors and subsequently are passaged into different generations of mice in order to maintain these tumors from patients. Importantly, cellular heterogeneity of the original tumor is closely emulated in this model, which provides a more clinically relevant model for evaluation of drug efficacy studies (single agent and combination), biomarker analysis, resistant pathways and cancer stem cell biology. Some limitations of the PDTX model include the replacement of the human stroma with mouse stroma after the first generation in mice, inability to investigate treatment effects on metastasis due to the subcutaneous injections of the tumors, and the lack of evaluation of immunotherapies due to the use of immunocompromised mice. However, even with these limitations, the PDTX model provides a powerful preclinical platform in the drug discovery process.

Utilizing patient-derived tumors in a subcutaneous preclinical model is an excellent way to study the efficacy of novel therapies, predictive biomarker discovery, and drug resistant pathways. This model, in the drug development process, is essential in determining the fate of many novel anti-cancer therapies prior to clinical investigation.

Patient derived tumor xenograft (PDTX) models provide a necessary platform in facilitating anti-cancer drug development prior to human trials. Human tumor ...

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

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

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

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

Orthotopic Transplantation of Syngeneic Lung Adenocarcinoma Cells to Study PD-L1 Expression

The use of mouse models is indispensable for studying the pathophysiology of various diseases. With respect to lung cancer, several models are available, including genetically engineered models as well as transplantation models. However, genetically engineered mouse models are time-consuming and expensive, whereas some orthotopic transplantation models are difficult to reproduce. Here, a non-invasive intratracheal delivery method of lung tumor cells as an alternative orthotopic transplantation model is described. The use of mouse lung adenocarcinoma cells and syngeneic graft recipients allows studying tumorigenesis under the presence of a fully active immune system. Furthermore, genetic manipulations of tumor cells before transplantation makes this model an attractive time-saving approach to study the impact of genetic factors on tumor growth and tumor cell gene expression profiles under physiological conditions. Using this model, we show that lung adenocarcinoma cells express increased levels of the T-cell suppressor programmed death-ligand 1 (PD-L1) when grown in their natural environment as compared to cultivation in vitro.

Here we describe a minimally invasive syngeneic orthotopic transplantation model of mouse lung adenocarcinoma cells as a time- and cost-reducing model to study non-small cell lung cancer.

The use of mouse models is indispensable for studying the pathophysiology of various diseases. With respect to lung cancer, several models are available, ...

Patient-derived Orthotopic Xenograft Models for Human Urothelial Cell Carcinoma and Colorectal Cancer Tumor Growth and Spontaneous Metastasis

Cancer patients have poor prognoses when lymph node (LN) involvement is present in both high-grade urothelial cell carcinoma (HG-UCC) of the bladder and colorectal cancer (CRC). More than 50% of patients with muscle-invasive UCC, despite curative therapy for clinically-localized disease, will develop metastases and die within 5 years, and metastatic CRC is a leading cause of cancer-related deaths in the US. Xenograft models that consistently mimic UCC and CRC metastasis seen in patients are needed. This study aims to generate patient-derived orthotopic xenograft (PDOX) models of UCC and CRC for primary tumor growth and spontaneous metastases under the influence of LN stromal cells mimicking the progression of human metastatic diseases for drug screening. Fresh UCC and CRC tumors were obtained from consented patients undergoing resection for HG-UCC and colorectal adenocarcinoma, respectively. Co-inoculated with LN stromal cell (LNSC) analog HK cells, luciferase-tagged UCC cells were intra-vesically (IB) instilled into female non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice, and CRC cells were intra-rectally (IR) injected into male NOD/SCID mice. Tumor growth and metastasis were monitored weekly using bioluminescence imaging (BLI). Upon sacrifice, primary tumors and mouse organs were harvested, weighed, and formalin-fixed for Hematoxylin and Eosin and immunohistochemistry staining. In our unique PDOX models, xenograft tumors resemble patient pre-implantation tumors. In the presence of HK cells, both models have high tumor implantation rates measured by BLI and tumor weights, 83.3% for UCC and 96.9% for CRC, and high distant organ metastasis rates (33.3% detected liver or lung metastasis for UCC and 53.1% for CRC). In addition, both models have zero mortality from the procedure. We have established unique, reproducible PDOX models for human HG-UCC and CRC, which allow for tumor formation, growth, and metastasis studies. With these models, testing of novel therapeutic drugs can be performed efficiently and in a clinically-mimetic manner.

This protocol describes the generation of patient-derived orthotopic xenograft models by intra-vesically instilling high-grade urothelial cell carcinoma cells or intra-rectally injecting colorectal cancer cells into non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice for primary tumor growth and spontaneous metastases under the influence of lymph node stromal cells, which mimics the progression of human metastatic diseases.

Cancer patients have poor prognoses when lymph node (LN) involvement is present in both high-grade urothelial cell carcinoma (HG-UCC) of the bladder and ...

Testing Targeted Therapies in Cancer using Structural DNA Alteration Analysis and Patient-Derived Xenografts

We present here an integrative approach for testing efficacy of targeted therapies that combines the next generation sequencing technolo-gies, therapeutic target analyses and drug response monitoring using patient derived xenografts (PDX). This strategy was validated using ovarian tumors as an example. The mate-pair next generation sequencing (MPseq) protocol was used to identify structural alterations and followed by analysis of potentially targetable alterations. Human tumors grown in immunocompromised mice were treated with drugs selected based on the genomic analyses. Results demonstrated a good correlation between the predicted and the observed responses in the PDX model. The presented approach can be used to test the efficacy of combination treatments and aid personalized treatment for patients with recurrent cancer, specifically in cases when standard therapy fails and there is a need to use drugs off label.

Here we present a protocol to test the efficacy of targeted therapies selected based on the genomic makeup of a tumor. The protocol describes identification and validation of structural DNA rearrangements, engraftment of patients&#8217; tumors into mice and testing responses to corresponding drugs.

We present here an integrative approach for testing efficacy of targeted therapies that combines the next generation sequencing technolo-gies, therapeutic ...

Generation of an Orthotopic Xenograft of Pancreatic Cancer Cells by Ultrasound-Guided Injection

Pancreatic cancer (PCa) represents one of the deadliest cancer types worldwide. The reasons for PCa malignancy mainly rely on its intrinsic malignant behavior and high resistance to therapeutic treatments. Indeed, despite many efforts, both standard chemotherapy and innovative target therapies have substantially failed when moved from preclinical evaluation to the clinical setting. In this scenario, the development of preclinical mouse models better mimicking in vivo characteristics of PCa is urgently needed to test newly developed drugs. The present protocol describes a method to generate a mouse model of PCa, represented by an orthotopic xenograft obtained by ultrasound-guided injection of human pancreatic tumor cells. Using such a reliable and minimally invasive protocol, we also provide evidence of in vivo engraftment and development of tumor masses, which can be monitored by ultrasound (US) imaging. A noteworthy aspect of the PCa model described here is the slow development of the tumor masses over time, which allows precise identification of the starting point for pharmacological treatments and better monitoring of the effects of therapeutic interventions. Moreover, the technique described here is an example of implementation of the 3Rs principles since it minimizes pain and suffering and directly improves the welfare of animals in research.

We present a protocol to generate a minimally invasive orthotopic pancreatic cancer model by ultrasound-guided injection of human pancreatic cancer cells and the subsequent monitoring of tumor growth in vivo by ultrasound imaging.

Pancreatic cancer (PCa) represents one of the deadliest cancer types worldwide. The reasons for PCa malignancy mainly rely on its intrinsic malignant ...

A Combined 3D Tissue Engineered In Vitro/In Silico Lung Tumor Model for Predicting Drug Effectiveness in Specific Mutational Backgrounds

In the present study, we combined an in vitro 3D lung tumor model with an in silico model to optimize predictions of drug response based on a specific mutational background. The model is generated on a decellularized porcine scaffold that reproduces tissue-specific characteristics regarding extracellular matrix composition and architecture including the basement membrane. We standardized a protocol that allows artificial tumor tissue generation within 14 days including three days of drug treatment. Our article provides several detailed descriptions of 3D read-out screening techniques like the determination of the proliferation index Ki67 staining&#39;s, apoptosis from supernatants by M30-ELISA and assessment of epithelial to mesenchymal transition (EMT), which are helpful tools for evaluating the effectiveness of therapeutic compounds. We could show compared to 2D culture a reduction of proliferation in our 3D tumor model that is related to the clinical situation. Despite of this lower proliferation, the model predicted EGFR-targeted drug responses correctly according to the biomarker status as shown by comparison of the lung carcinoma cell lines HCC827 (EGFR -mutated, KRAS wild-type) and A549 (EGFR wild-type, KRAS-mutated) treated with the tyrosine-kinase inhibitor (TKI) gefitinib. To investigate drug responses of more advanced tumor cells, we induced EMT by long-term treatment with TGF-beta-1 as assessed by vimentin/pan-cytokeratin immunofluorescence staining. A flow-bioreactor was employed to adjust culture to physiological conditions, which improved tissue generation. Furthermore, we show the integration of drug responses upon gefitinib treatment or TGF-beta-1 stimulation - apoptosis, proliferation index and EMT - into a Boolean in silico model. Additionally, we explain how drug responses of tumor cells with a specific mutational background and counterstrategies against resistance can be predicted. We are confident that our 3D in vitro approach especially with its in silico expansion provides an additional value for preclinical drug testing in more realistic conditions than in 2D cell culture.

A Combined 3D Tissue Engineered In Vitro/In Silico Lung Tumor Model for Predicting Drug Effectiveness in Specific Mutational Backgrounds

We present a three-dimensional (3D) lung cancer model based on a biological collagen scaffold to study sensitivity towards non-small-cell-lung-cancer-(NSCLC)-targeted therapies. We demonstrate different read-out techniques to determine the proliferation index, apoptosis and epithelial-mesenchymal transition (EMT) status. Collected data are integrated into an in silico model for prediction of drug sensitivity.

In the present study, we combined an in vitro 3D lung tumor model with an in silico model to optimize predictions of drug response based on a specific ...

Bioengineering

Establishment and Characterization of Patient-Derived Xenograft Models of Anaplastic Thyroid Carcinoma and Head and Neck Squamous Cell Carcinoma

Patient-derived xenograft (PDX) models faithfully preserve the histological and genetic characteristics of the primary tumor and maintain its heterogeneity. Pharmacodynamic results based on PDX models are highly correlated with clinical practice. Anaplastic thyroid carcinoma (ATC) is the most malignant subtype of thyroid cancer, with strong invasiveness, poor prognosis, and limited treatment. Although the incidence rate of ATC accounts for only 2%-5% of thyroid cancer, its mortality rate is as high as 15%-50%. Head and neck squamous cell carcinoma (HNSCC) is one of the most common head and neck malignancies, with over 600,000 new cases worldwide each year. Herein, detailed protocols are presented to establish PDX models of ATC and HNSCC. In this work, the key factors influencing the success rate of model construction were analyzed, and the histopathological features were compared between the PDX model and the primary tumor. Furthermore, the clinical relevance of the model was validated by evaluating the in vivo therapeutic efficacy of representative clinically used drugs in the successfully constructed PDX models.

The present protocol establishes and characterizes a patient-derived xenograft (PDX) model of anaplastic thyroid carcinoma (ATC) and head and neck squamous cell carcinoma (HNSCC), as PDX models are rapidly becoming the standard in the field of translational oncology.

Patient-derived xenograft (PDX) models faithfully preserve the histological and genetic characteristics of the primary tumor and maintain its ...

Pre-clinical Orthotopic Murine Model of Human Prostate Cancer

To study the multifaceted biology of prostate cancer, pre-clinical in vivo models offer a range of options to uncover critical biological information about this disease. The human orthotopic prostate cancer xenograft mouse model provides a useful alternative approach for understanding the specific interactions between genetically and molecularly altered tumor cells, their organ microenvironment, and for evaluation of efficacy of therapeutic regimens. This is a well characterized model designed to study the molecular events of primary tumor development and it recapitulates the early events in the metastatic cascade prior to embolism and entry of tumor cells into the circulation. Thus it allows elucidation of molecular mechanisms underlying the initial phase of metastatic disease. In addition, this model can annotate drug targets of clinical relevance and is a valuable tool to study prostate cancer progression. In this manuscript we describe a detailed procedure to establish a human orthotopic prostate cancer xenograft mouse model.

Prostate cancer is the second most common cause of cancer-related deaths in the United States. An orthotopic cancer model provides a useful approach to understand the biology of prostate cancer and to evaluate the efficacy of therapeutic regimens. This protocol describes detailed steps necessary to establish an orthotopic prostate cancer mouse model.

To study the multifaceted biology of prostate cancer, pre-clinical in vivo models offer a range of options to uncover critical biological information ...

Medicine

Depletion of Mouse Cells from Human Tumor Xenografts Significantly Improves Downstream Analysis of Target Cells

The use of in vitro cell line models for cancer research has been a useful tool. However, it has been shown that these models fail to reliably mimic patient tumors in different assays1. Human tumor xenografts represent the gold standard with respect to tumor biology, drug discovery, and metastasis research 2-4. Tumor xenografts can be derived from different types of material like tumor cell lines, tumor tissue from primary patient tumors4 or serially transplanted tumors. When propagated in vivo, xenografted tissue is infiltrated and vascularized by cells of mouse origin. Multiple factors such as the tumor entity, the origin of xenografted material, growth rate and region of transplantation influence the composition and the amount of mouse cells present in tumor xenografts. However, even when these factors are kept constant, the degree of mouse cell contamination is highly variable.
Contaminating mouse cells significantly impair downstream analyses of human tumor xenografts. As mouse fibroblasts show high plating efficacies and proliferation rates, they tend to overgrow cultures of human tumor cells, especially slowly proliferating subpopulations. Mouse cell derived DNA, mRNA, and protein components can bias downstream gene expression analysis, next-generation sequencing, as well as proteome analysis 5. To overcome these limitations, we have developed a fast and easy method to isolate untouched human tumor cells from xenografted tumor tissue. This procedure is based on the comprehensive depletion of cells of mouse origin by combining automated tissue dissociation with the benchtop tissue dissociator and magnetic cell sorting. Here, we demonstrate that human target cells can be can be obtained with purities higher than 96% within less than 20 min independent of the tumor type.

Human tumor xenografts are vascularized and infiltrated by cells of mouse origin during the growth phase in vivo. To circumvent the bias caused by these contaminating cells during downstream analysis, we developed a method allowing for comprehensive depletion of all mouse cells by magnetic cell sorting.

The use of in vitro cell line models for cancer research has been a useful tool. However, it has been shown that these models fail to reliably mimic ...

Construction of An Orthotopic Xenograft Model of Non-Small Cell Lung Cancer Mimicking Disease Progression and Predicting Drug Activities

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Chapters in this video

Development and Maintenance of a Preclinical Patient Derived Tumor Xenograft Model for the Investigation of Novel Anti-Cancer Therapies

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

Orthotopic Transplantation of Syngeneic Lung Adenocarcinoma Cells to Study PD-L1 Expression

Patient-derived Orthotopic Xenograft Models for Human Urothelial Cell Carcinoma and Colorectal Cancer Tumor Growth and Spontaneous Metastasis

Testing Targeted Therapies in Cancer using Structural DNA Alteration Analysis and Patient-Derived Xenografts

Generation of an Orthotopic Xenograft of Pancreatic Cancer Cells by Ultrasound-Guided Injection

A Combined 3D Tissue Engineered In Vitro/In Silico Lung Tumor Model for Predicting Drug Effectiveness in Specific Mutational Backgrounds

Establishment and Characterization of Patient-Derived Xenograft Models of Anaplastic Thyroid Carcinoma and Head and Neck Squamous Cell Carcinoma

Pre-clinical Orthotopic Murine Model of Human Prostate Cancer

Depletion of Mouse Cells from Human Tumor Xenografts Significantly Improves Downstream Analysis of Target Cells