We thank the members of the Y.D.S. laboratory. We would like to thank The Wohl Institute for Translational Medicine at the Hadassah Medical Center, Jerusalem, for providing the small animal imaging facility. This study was supported by Research Career Development Award from the Israel Cancer Research Fund.

All mouse experiments were carried out under the Hebrew University Institutional Animal Care and Use Committee-approved protocol MD-21-16429-5. In addition, the Hebrew University is certified by the Association for Assessment and Accreditation of Laboratory Animal Care (AAALAC).
1. Cell line maintenance
NOTE: The human breast cancer cell lines (MCF-7, MDA-MB-468, and MDA-MB-231) were used in this protocol.
<ol>
	<li>Culture all the breast cancer cell lines in Dulb...

<ol>
	<li>Waks, A. G., Winer, E. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Breast+cancer+treatment:+A+review.">Breast cancer treatment: A review.</a> JAMA. 321 (3), 288-300 (2019).</li><li>Jin, X., Mu, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Targeting+breast+cancer+metastasis.">Targeting breast cancer metastasis.</a> Breast Cancer: Basic and Clinical Research. 9, 23-34 (2015).</li><li>Saha, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+bioluminescence+imaging+of+tumor+hypoxia+dynamics+of+breast+cancer+brain+metastasis+in+a+mouse+model.">In vivo bioluminescence imaging of tumor hypoxia dynamics of breast cancer brain metastasis in a mouse model.</a> Journal of Visualized Experiments: JoVE. (56), e3175 (2011).</li><li>Rashid, O. 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=Is+tail+vein+injection+a+relevant+breast+cancer+lung+metastasis+model.">Is tail vein injection a relevant breast cancer lung metastasis model.</a> Journal of Thoracic Disease. 5 (4), 385-392 (2013).</li><li>Fantozzi, A., Christofori, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+models+of+breast+cancer+metastasis.">Mouse models of breast cancer metastasis.</a> Breast Cancer Research. 8 (4), 212 (2006).</li><li>Kocat&#252;rk, B., Versteeg, H. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Orthotopic+injection+of+breast+cancer+cells+into+the+mammary+fat+pad+of+mice+to+study+tumor+growth.">Orthotopic injection of breast cancer cells into the mammary fat pad of mice to study tumor growth.</a> Journal of Visualized Experiments: JoVE. (96), e51967 (2015).</li><li>Baker, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+whole+picture.">The whole picture.</a> Nature. 463 (7283), 977-979 (2010).</li><li>Wang, Y., Tseng, J. -. C., Sun, Y., Beck, A. H., Kung, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Noninvasive+imaging+of+tumor+burden+and+molecular+pathways+in+mouse+models+of+cancer.">Noninvasive imaging of tumor burden and molecular pathways in mouse models of cancer.</a> Cold Spring Harbor Protocols. 2015 (2), 135-144 (2015).</li><li>Kim, J. E., Kalimuthu, S., Ahn, B. -. C. <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+cell+tracking+with+bioluminescence+imaging.">In vivo cell tracking with bioluminescence imaging.</a> Nuclear Medicine and Molecular Imaging. 49 (1), 3-10 (2015).</li><li>Paschall, A. V., Liu, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+orthotopic+mouse+model+of+spontaneous+breast+cancer+metastasis.">An orthotopic mouse model of spontaneous breast cancer metastasis.</a> Journal of Visualized Experiments: JoVE. (114), (2016).</li><li>Morten, B. C., Scott, R. J., Avery-Kiejda, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+Three+Different+Methods+for+Determining+Cell+Proliferation+in+Breast+Cancer+Cell+Lines.">Comparison of Three Different Methods for Determining Cell Proliferation in Breast Cancer Cell Lines.</a> Journal of Visualized Experiments. (115), e54040 (2016).</li><li>Zimmerman, M., Hu, X., Liu, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+metastasis+and+CTL+adoptive+transfer+immunotherapy+mouse+model.">Experimental metastasis and CTL adoptive transfer immunotherapy mouse model.</a> Journal of Visualized Experiments: JoVE. (45), e2077 (2010).</li><li>Lv, 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=Orthotopic+transplantation+of+breast+tumors+as+preclinical+models+for+breast+cancer.">Orthotopic transplantation of breast tumors as preclinical models for breast cancer.</a> Journal of Visualized Experiments: JoVE. (159), e61173 (2020).</li><li>Cheng, R. Y. 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=Studying+triple+negative+breast+cancer+using+orthotopic+breast+cancer+model.">Studying triple negative breast cancer using orthotopic breast cancer model.</a> Journal of Visualized Experiments: JoVE. (157), e60316 (2020).</li><li>Bajikar, S. 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=Tumor-suppressor+inactivation+of+GDF11+occurs+by+precursor+sequestration+in+triple-negative+breast+cancer.">Tumor-suppressor inactivation of GDF11 occurs by precursor sequestration in triple-negative breast cancer.</a> Developmental Cell. 43 (4), 418-435 (2017).</li><li>Khatib, 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=The+glutathione+peroxidase+8+(GPX8)/IL-6/STAT3+axis+is+essential+in+maintaining+an+aggressive+breast+cancer+phenotype.">The glutathione peroxidase 8 (GPX8)/IL-6/STAT3 axis is essential in maintaining an aggressive breast cancer phenotype.</a> Proceedings of the National Academy of Sciences of the United States of America. 117 (35), 21420-21431 (2020).</li></ol>

Animal-based experiments are obligatory for cancer research7,8,9, and indeed many protocols have been developed3,6,10,11,12,13,14. However, most of these studies determined the biological effect onl...

Breast cancers are frequent types of cancer worldwide, with approximately 250,000 new cases diagnosed each year in the United States1. Despite its high incidence, a new set of anticancer drugs has significantly improved breast cancer patient outcomes2. However, these treatments are still inadequate, as many patients experience disease relapse and metastatic spread to vital organs2, which is the primary cause of patient morbidity and mortality. Therefore, one of the main challenges in breast cancer research is identifying the molecular mechanisms regulating the formation of distal metastases to develop new means to inhibit their development.
Cancer metastasis is a dynamic process in which cells detach from the primary tumor and invade neighboring tissues through the blood circulation. Thus, animal models in which the cells undergo a similar metastatic cascade can facilitate the identification of the mechanisms that govern this process3,4. Additionally, these in vivo models are essential for developing breast cancer therapeutic agents5,6. However, these orthotopic models cannot indicate the actual tumor growth kinetics as the effect is only determined upon termination. Therefore, we established a luciferase-based tool to detect tumor development and metastatic colonization in real time. Additionally, these cells express GFP to detect the metastatic colonies. This approach is relatively simple and does not involve any invasive procedures3. Thus, combining luciferase and fluorescence detection is a helpful strategy to advance the preclinical studies of breast cancer therapeutics and disease management.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>1.7 mL eppendorf tubes</td>
			<td>Lifegene</td>
			<td>LMCT1.7B-500</td>
			<td></td>
		</tr>
		<tr>
			<td>10 &#181;L tips</td>
			<td>Lifegene</td>
			<td>LRT10</td>
			<td></td>
		</tr>
		<tr>
			<td>1000 &#181;L tips</td>
			<td>Lifegene</td>
			<td>LRT1000</td>
			<td></td>
		</tr>
		<tr>
			<td>15 mL tubes</td>
			<td>Lifegene</td>
			<td>LTB15-500</td>
			<td></td>
		</tr>
		<tr>
			<td>200 &#181;L tips</td>
			<td>Lifegene</td>
			<td>LRT200</td>
			<td></td>
		</tr>
		<tr>
			<td>6 well cell culture plate</td>
			<td>COSTAR</td>
			<td>3516</td>
			<td></td>
		</tr>
		<tr>
			<td>96 well Plates BLACK flat bottom</td>
			<td>Bar Naor</td>
			<td>BN30496</td>
			<td></td>
		</tr>
		<tr>
			<td>Automated Cell Counters</td>
			<td>Thermofisher</td>
			<td>A50298</td>
			<td></td>
		</tr>
		<tr>
			<td>BD FACSAria III sorter</td>
			<td>BD</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>BD Microlance 3 Needles 27 G (3/4&#39;&#39;)</td>
			<td>BD</td>
			<td>302200</td>
			<td></td>
		</tr>
		<tr>
			<td>BD Plastipak Syringes 1 mL x 120</td>
			<td>BD</td>
			<td>303172</td>
			<td></td>
		</tr>
		<tr>
			<td>Corning 100 mm x 20 mm Style Dish</td>
			<td>CORNING</td>
			<td>430167</td>
			<td></td>
		</tr>
		<tr>
			<td>Corning 150 mm x 20 mm Style Dish</td>
			<td>CORNING</td>
			<td>430599</td>
			<td></td>
		</tr>
		<tr>
			<td>Countess cell counting chamber slides</td>
			<td>Thermofisher</td>
			<td>C10228</td>
			<td></td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s modified Eagle&#39;s medium (DMEM), high glucose, no glutamine</td>
			<td>Biological Industries</td>
			<td>01-055-1A</td>
			<td></td>
		</tr>
		<tr>
			<td>Eclipse 80i microscope</td>
			<td>Nikon</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>eppendorf Centrifuge 5810 R</td>
			<td>Sigma Aldrich</td>
			<td>EP5820740000</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum (FBS)</td>
			<td>Biological Industries</td>
			<td>04-127-1A</td>
			<td></td>
		</tr>
		<tr>
			<td>FUW GFP</td>
			<td></td>
			<td></td>
			<td>Gifted from Dr. Yossi Buganim&#39;s lab (Hebrew University of Jerusalem)</td>
		</tr>
		<tr>
			<td>HEK293T</td>
			<td></td>
			<td></td>
			<td>Gifted from Dr. Lior Nissim&#39;s lab (Hebrew University of Jerusalem)</td>
		</tr>
		<tr>
			<td>Isoflurane, USP Terrell</td>
			<td>Piramal</td>
			<td>NDC 66794-01-25</td>
			<td></td>
		</tr>
		<tr>
			<td>IVIS Spectrum In Vivo Imaging System</td>
			<td>Perkin Elmer</td>
			<td>124262</td>
			<td></td>
		</tr>
		<tr>
			<td>L-Glutamine Solution</td>
			<td>Biological industries</td>
			<td>03-020-1A</td>
			<td></td>
		</tr>
		<tr>
			<td>Living Image Software</td>
			<td>PerkinElmer</td>
			<td></td>
			<td>bioluminescence measurement</td>
		</tr>
		<tr>
			<td>MCF-7</td>
			<td>ATCC</td>
			<td>ATCC HTB-22</td>
			<td></td>
		</tr>
		<tr>
			<td>MDA-MB-231</td>
			<td>ATCC</td>
			<td>ATCC HTB-26</td>
			<td></td>
		</tr>
		<tr>
			<td>MDA-MB-468</td>
			<td>ATCC</td>
			<td>ATCC HTB-132</td>
			<td></td>
		</tr>
		<tr>
			<td>Pasteur pipettes</td>
			<td>NORMAX</td>
			<td>2430-475</td>
			<td></td>
		</tr>
		<tr>
			<td>PBS</td>
			<td>Hylabs</td>
			<td>BP655/500D</td>
			<td></td>
		</tr>
		<tr>
			<td>pCMV-dR8.2-dvpr</td>
			<td>Addgene</td>
			<td>#8455</td>
			<td>Provided by David M. Sabatini&#8217;s lab (Whitehead institute, Boston, USA)</td>
		</tr>
		<tr>
			<td>pCMV-VSV-G</td>
			<td>Addgene</td>
			<td>#8454</td>
			<td>Provided by David M. Sabatini&#8217;s lab (Whitehead institute, Boston, USA)</td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin Solution</td>
			<td>Biological Industries</td>
			<td>03-031-1B</td>
			<td></td>
		</tr>
		<tr>
			<td>Petri dish 90 mm (90x15)</td>
			<td>MINI PLAST</td>
			<td>820-090-01-017</td>
			<td></td>
		</tr>
		<tr>
			<td>Pipettes 10ml</td>
			<td>Lifegene</td>
			<td>LG-GSP010010S</td>
			<td></td>
		</tr>
		<tr>
			<td>Pipettes 25ml</td>
			<td>Lifegene</td>
			<td>LG-GSP010050S</td>
			<td></td>
		</tr>
		<tr>
			<td>Pipettes 5ml</td>
			<td>Lifegene</td>
			<td>LG-GSP010005S</td>
			<td></td>
		</tr>
		<tr>
			<td>pLX304 Luciferase-V5 blast plasmid</td>
			<td>Addgene</td>
			<td>#98580</td>
			<td></td>
		</tr>
		<tr>
			<td>Polybrene</td>
			<td>Sigma Aldrich</td>
			<td>#107689</td>
			<td></td>
		</tr>
		<tr>
			<td>Prism 9</td>
			<td>GraphPad</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Reagent Reservoirs</td>
			<td>Bar Naor</td>
			<td>BN20621STR200TC</td>
			<td></td>
		</tr>
		<tr>
			<td>SMZ18 Stereo microscopes</td>
			<td>Nikon</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium Chloride</td>
			<td>Bio-Lab</td>
			<td>190359400</td>
			<td></td>
		</tr>
		<tr>
			<td>Syringe filters</td>
			<td>Lifegene</td>
			<td>LG-FPV403030S</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypan Blue 0.5% solution</td>
			<td>Biological industries</td>
			<td>03-102-1B</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin EDTA Solution B (0.25%), EDTA (0.05%)</td>
			<td>Biological Industries</td>
			<td>03-052-1a</td>
			<td></td>
		</tr>
		<tr>
			<td>Vacuum driven Filters</td>
			<td>SOFRA LIFE SCIENCE</td>
			<td>SPE-22-500</td>
			<td></td>
		</tr>
		<tr>
			<td>Virusolve</td>
			<td></td>
			<td>disinfectant</td>
			<td></td>
		</tr>
		<tr>
			<td>VivoGlo Luciferin, In Vivo Grade</td>
			<td>Promega</td>
			<td>P1043</td>
			<td></td>
		</tr>
		<tr>
			<td>X-tremeGENE HP DNA Transfection Reagent</td>
			<td>Sigma Aldrich</td>
			<td>#6366236001</td>
			<td></td>
		</tr>
	</tbody>
</table>

monitoring breast cancer growth and metastatic colony formation in mice using bioluminescence

Breast cancer is a frequent heterogeneous malignancy and the second leading cause of mortality in women, mainly due to distant organ metastasis. Several animal models have been generated, including the widely used orthotopic mouse models, where cancer cells are injected into the mammary fat pad. However, these models cannot help monitor tumor growth kinetics and metastatic colonization. Cutting-edge tools to monitor cancer cells in real time in mice will significantly advance the understanding of tumor biology. 
Here, breast cancer cell lines stably expressing luciferase and green fluorescent protein (GFP) were established. Specifically, this technique contains two sequential steps initiated by measuring the luciferase activity in vitro and followed by the implantation of the cancer cells into mammary fat pads of nonobese diabetic-severe combined immunodeficiency (NOD-SCID) mice. After the injection, both the tumor growth and metastatic colonization are monitored in real time by the noninvasive bioluminescence imaging system. Then, the quantification of GFP-expressing metastases in the lungs will be examined by fluorescence microscopy to validate the observed bioluminescence results. This sophisticated system combining luciferase and fluorescence-based detection tools evaluates cancer metastasis in vivo, which has great potential for use in breast cancer therapeutics and disease management.

We generated breast cancer cell lines (MDA-MB-231, MCF-7, and MDA-MB-468) expressing GFP and luciferase vectors. Specifically, this was achieved by a sequential infection. First, the breast cancer cell lines were infected with a lentivirus vector expressing fluorescent GFP. The GFP-positive cells (GFP+) were sorted 2 days post-infection (Figure 1A,B) and infected with the pLX304 Luciferase-V5 vector. Then, blasticidin was used to select for luciferase to generate ...

Watch this Scientific Journal Video about Monitoring Breast Cancer Growth and Metastatic Colony Formation in Mice using Bioluminescence at JoVE.com

Monitoring Breast Cancer Growth and Metastatic Colony Formation in Mice using Bioluminescence

Here, we describe a noninvasive monitoring method involving luciferase and green fluorescent protein expression in various breast cancer cell lines. This protocol provides a technique to monitor tumor formation and metastatic colonization in real time in mice.

Breast cancer is a frequent heterogeneous malignancy and the second leading cause of mortality in women, mainly due to distant organ metastasis. Several ...

Using this sophisticated, non-invasive tool, we can real-time monitor tumor growth kinetics and metastatic colonization in mice, which has a great potential in breast cancer therapeutic and disease management. Combining luciferase and fluorescence detection is a helpful strategy to advance the preclinical studies of breast cancer progression and disease management. This can be applied for anticancer drug studies.This protocol is not restricted to breast cancer and could be applied to other carcinomas, such as lung and pancreatic. Start by growing the MCF-7, MDA-MB-468, and MDA-MB-231 GFP and luciferase-positive cells separately in a 16-centimeter plate to 80%confluency. After harvesting the cells by trypsinization, seed an increasing number of cells in each well into a black 96-well plate.Then, fill all the wells with 100 microliters of DMEM, and incubate for 16 to 24 hours in 37 degrees Celsius, 5%CO2 incubator. Prepare luciferin solution in PBS at a 1.5-milligrams-per-milliliter concentration, and store the solution at minus 20 degrees Celsius. Post-incubation, wash the cells once with PBS gently before adding 100 microliters of luciferin solution into each well.Wait for two minutes, and then measure the luciferase activity in all the breast cancer cells using bioluminescence. Before injecting the mouse, transfer five million MCF-7 and MDA-MB-468 cells into 200 microliters of PBS and two million MDA-MB-231 GFP and luciferase-positive cells into 100 microliters PBS. Prepare the anesthetized mouse for injection by placing a cone over the head in a supine position.Next, wipe the abdominal area of the mouse above the mammary gland with ethanol using a cotton swab, and lift the fourth mammary gland with forceps before inserting a 27-gauge needle under the fat pad to slowly inject 100 microliters of the prepared cell suspension. After the injection, take the mouse out of the hood and transfer it to a new cage under observation until it returns to consciousness. Before the bioluminescence detection, restrain the conscious mouse by holding its neck with the left hand and tilting the hand to the left, resulting in the face of the mouse upward with the lower body in a supine position.Inject 100 microliters of 30-milligrams-per-milliliter luciferin intraperitoneally into the lower left abdominal quadrant of the mouse using a one-milliliter syringe. Keep the mouse for seven minutes without anesthesia, followed by three minutes within the anesthesia chamber before measuring the tumor kinetics. While the mouse is under incubation, open the software and initialize the imaging system by clicking the Initialize button.Keep the setup in auto exposure with exposure time in the auto at 60 seconds, binning medium at an aperture of f/stop one, excitation filter blocked, and emission filter open. When initialization ends, select Imaging Wizard and Bioluminescence and then click Next, Open Filter to select mouse in the image subject. In the field view, select stage C at 10 centimeters and subject height at 1.50 centimeters.Then, click Image Setup Stage to C.Ensure that the mouse is placed on the stage in the proper supine position before closing the door and clicking the Acquire button. Wait for an image to appear on the screen. Repeat the procedure for the other mouse.To detect lung metastasis, cover the strong signal of the primary tumor using a thick cardboard paper and expose only the ventral side of the lungs towards the camera. Capture the image using the same parameters as described earlier. The breast cancer cell lines were infected with a lentivirus vector expressing fluorescent GFP and subject to FAC sorting.The GFP-positive cells were sorted two days post-infection, plated and visualized by fluorescence microscope. The in vitro luciferase activity was confirmed with a cell number-dependent increase in the luciferase activity levels. In addition, a linear correlation was found between the luciferase activity and the cell number.After injecting the breast cancer cell lines, the mice were subjected to bioluminescence reading every two weeks to determine the tumor growth kinetics. The tumor growth kinetics was faster in the MDA-MB-231 cell lines than in the less aggressive cell lines, MCF-7 and MDA-MB-468. The luminescence activity was quantified for three cell lines.Six weeks post-injection, the harvested tumors were found to maintain the GFP expression. Also, positive bioluminescence readings were obtained from the lung of the whole mouse in real time. The lung was harvested to verify positive metastatic colonies, and the metastatic colonies were observed for GFP and bioluminescence.It is more important to be careful while performing the injection procedure. An improper injection may lead to deviation in the tumor growth rate or absence of tumor. We can examine the lung metastasis in vivo and ex vivo by detecting GFP expression.In addition, we can also study the histopathology of lungs by immunohistochemistry-based staining. This technique can be useful to explore the new questions, such as the effect of drug efficacy studies.

monitoring-breast-cancer-growth-metastatic-colony-formation-mice

Research

JoVE Journal

Cancer Research

2.8K Views.  The Hebrew University-Hadassah Medical School. Using this sophisticated, non-invasive tool, we can real-time monitor tumor growth kinetics and metastatic colonization in mice, which has a great potential in breast cancer therapeutic and disease management. Combining luciferase and fluorescence detection is a helpful strategy to advance the preclinical studies of breast cancer progression and disease management. This can be applied for anticancer drug studies.This protocol is not restricted to breast cancer and could be applied to o...

Video: Monitoring Breast Cancer Growth and Metastatic Colony Formation in Mice using Bioluminescence

Utilizing Functional Genomics Screening to Identify Potentially Novel Drug Targets in Cancer Cell Spheroid Cultures

The identification of functional driver events in cancer is central to furthering our understanding of cancer biology and indispensable for the discovery of the next generation of novel drug targets. It is becoming apparent that more complex models of cancer are required to fully appreciate the contributing factors that drive tumorigenesis in vivo and increase the efficacy of novel therapies that make the transition from pre-clinical models to clinical trials.
Here we present a methodology for generating uniform and reproducible tumor spheroids that can be subjected to siRNA functional screening. These spheroids display many characteristics that are found in solid tumors that are not present in traditional two-dimension culture. We show that several commonly used breast cancer cell lines are amenable to this protocol. Furthermore, we provide proof-of-principle data utilizing the breast cancer cell line BT474, confirming their dependency on amplification of the epidermal growth factor receptor HER2 and mutation of phosphatidylinositol-4,5-biphosphate 3-kinase (PIK3CA) when grown as tumor spheroids. Finally, we are able to further investigate and confirm the spatial impact of these dependencies using immunohistochemistry.

Identifying novel drug targets that transition from pre-clinical testing to human trials is a scientific priority. To that end, here we describe a functional genomics approach for examining the impact of gene depletion on cancer cell line spheroids, which more appropriately model human cancers in vivo.

The identification of functional driver events in cancer is central to furthering our understanding of cancer biology and indispensable for the discovery ...

Labeling of Breast Cancer Patient-derived Xenografts with Traceable Reporters for Tumor Growth and Metastasis Studies

The use of preclinical models to study tumor biology and response to treatment is central to cancer research. Long-established human cell lines, and many transgenic mouse models, often fail to recapitulate the key aspects of human malignancies. Thus, alternative models that better represent the heterogeneity of patients' tumors and their metastases are being developed. Patient-derived xenograft (PDX) models in which surgically resected tumor samples are engrafted into immunocompromised mice have become an attractive alternative as they can be transplanted through multiple generations,and more efficiently reflect tumor heterogeneity than xenografts derived from human cancer cell lines. A limitation to the use of PDXs is that they are difficult to transfect or transduce to introduce traceable reporters or to manipulate gene expression. The current protocol describes methods to transduce dissociated tumor cells from PDXs with high transduction efficiency, and the use of labeled PDXs for experimental models of breast cancer metastases. The protocol also demonstrates the use of labeled PDXs in experimental metastasis models to study the organ-colonization process of the metastatic cascade. Metastases to different organs can be easily visualized and quantified using bioluminescent imaging in live animals, or GFP expression during dissection and in excised organs. These methods provide a powerful tool to extend the use of multiple types of PDXs to metastasis research.

We describe a method for stable labeling of patient-derived xenografts (PDXs) with lentiviral particles expressing green-fluorescent protein and luciferase reporters. This method allows for tracking the growth of PDXs at the primary site, as well as detecting spontaneous and experimental metastases using in vivo imaging systems.

The use of preclinical models to study tumor biology and response to treatment is central to cancer research. Long-established human cell lines, and many ...

Practical Considerations in Studying Metastatic Lung Colonization in Osteosarcoma Using the Pulmonary Metastasis Assay

The pulmonary metastasis assay (PuMA) is an ex vivo lung explant and closed cell culture system that permits researchers to study the biology of lung colonization in osteosarcoma (OS) by fluorescence microscopy. This article provides a detailed description of the protocol, and discusses examples of obtaining image data on metastatic growth using widefield or confocal fluorescence microscopy platforms. The flexibility of the PuMA model permits researchers to study not only the growth of OS cells in the lung microenvironment, but also to assess the effects of anti-metastatic therapeutics over time. Confocal microscopy allows for unprecedented, high-resolution imaging of OS cell interactions with the lung parenchyma. Moreover, when the PuMA model is combined with fluorescent dyes or fluorescent protein genetic reporters, researchers can study the lung microenvironment, cellular and subcellular structures, gene function, and promoter activity in metastatic OS cells. The PuMA model provides a new tool for osteosarcoma researchers to discover new metastasis biology and assess the activity of novel anti-metastatic, targeted therapies.

The goal of this article is to provide a detailed description of the protocol for the pulmonary metastasis assay (PuMA). This model permits researchers to study metastatic osteosarcoma (OS) cell growth in lung tissue using a widefield fluorescence or confocal laser-scanning microscope.

The pulmonary metastasis assay (PuMA) is an ex vivo lung explant and closed cell culture system that permits researchers to study the biology of lung ...

Preclinical Assessment of the Bioactivity of the Anticancer Coumarin OT48 by Spheroids, Colony Formation Assays, and Zebrafish Xenografts

In vitro and in vivo pre-clinical screening of novel therapeutic agents are an essential tool in cancer drug discovery. Although human cancer cell lines respond to therapeutic compounds in 2D (dimensional) monolayer cell cultures, 3D culture systems were developed to understand the efficacy of drugs in more physiologically relevant models. In recent years, a paradigm shift was observed in pre-clinical research to validate the potency of new molecules in 3D culture systems, more precisely mimicking the tumor microenvironment. These systems characterize the disease state in a more physiologically relevant manner and help to gain better mechanistic insight and understanding of the pharmacological potency of a given molecule. Moreover, with the current trend in improving in vivo cancer models, zebrafish has emerged as an important vertebrate model to assess in vivo tumor formation and study the effect of therapeutic agents. Here, we investigated the therapeutic efficacy of hydroxycoumarin OT48 alone or in combination with BH3 mimetics in lung cancer cell line A549 by using three different 3D culture systems including colony formation assays (CFA), spheroid formation assay (SFA) and in vivo zebrafish xenografts.

Here, we present the preclinical screening of anticancer coumarins using 3D culture and zebrafish.

In vitro and in vivo pre-clinical screening of novel therapeutic agents are an essential tool in cancer drug discovery. Although human cancer cell lines ...

Orthotopic Injection of Breast Cancer Cells into the Mice Mammary Fat Pad

A proper animal model is crucial for a better understanding of diseases. Animal models established by different methods (subcutaneous injections, xenografts, genetic manipulation, chemical reagents induction, etc.) have various pathological characters and play important roles in investigating certain aspects of diseases. Although no single model can totally mimic the whole human disease progression, orthotopic organs disease models with a proper stromal environment play an irreplaceable role in understanding diseases and screening for potential drugs. In this article, we describe how to implant breast cancer cells into the mammary fat pad in a simple, less invasive, and easy-to-handle way, and follow the metastasis to distant organs. With the proper features of primary tumor growth, breast and nipple pathological changes, and a high occurrence of other organs&#39; metastasis, this model maximumly mimics human breast cancer progression. Primary tumor growth in situ, long-distant metastasis, and the tumor microenvironment of breast cancer can be investigated by using this model.

Here, we present a protocol to implant breast cancer cells into the mammary fat pad in a simple, less invasive, and easy-to-handle way, and this mouse orthotopic breast cancer model with a proper mammary fat pad environment can be used to investigate various aspects of cancer.

A proper animal model is crucial for a better understanding of diseases. Animal models established by different methods (subcutaneous injections, ...

Performing Data Mining And Integrative Analysis Of Biomarker in Breast Cancer Using Multiple Publicly Accessible Databases

In recent years, emerging databases were designed to lower the barriers for approaching the intricate cancer genomic datasets, thereby, facilitating investigators to analyze and interpret genes, samples and clinical data across different types of cancer. Herein, we describe a practical operation procedure, taking ID1 (Inhibitor of DNA binding proteins 1) as an example, to characterize the expression patterns of biomarker and survival predictors of breast cancer based on pooled clinical datasets derived from online accessible databases, including ONCOMINE, bcGenExMiner v4.0 (Breast cancer gene-expression miner v4.0), GOBO (Gene expression-based Outcome for Breast cancer Online), HPA (The human protein atlas), and Kaplan-Meier plotter. The analysis began with querying the expression pattern of the gene of interest (e.g., ID1) in cancerous samples vs. normal samples. Then, the correlation analysis between ID1 and clinicopathological characteristics in breast cancer was performed. Next, the expression profiles of ID1 was stratified according to different subgroups. Finally, the association between ID1 expression and survival outcome was analyzed. The operation procedure simplifies the concept to integrate multidimensional data types at the gene level from different databases and test hypotheses regarding recurrence and genomic context of gene alteration events in breast cancer. This method can improve the credibility and representativeness of the conclusions, thereby, present informative perspective on a gene of interest.

Here, we present a protocol to explore the biomarker and survival predictor of breast cancer based on the comprehensive analysis of pooled clinical datasets derived from a variety of publicly accessible databases, using the strategy of expression, correlation and survival analysis step by step.

In recent years, emerging databases were designed to lower the barriers for approaching the intricate cancer genomic datasets, thereby, facilitating ...

In Vivo Inhibition of MicroRNA to Decrease Tumor Growth in Mice

MicroRNAs (miRNAs) are important regulators of gene expression through their ability to destabilize mRNA and inhibit translation of target mRNAs. An ever-increasing number of studies have identified miRNAs as potential biomarkers for cancer diagnosis and prognosis, and also as therapeutic targets, adding an extra dimension to cancer evaluation and treatment. In the context of thyroid cancer, tumorigenesis results not only from mutations in important genes, but also from the overexpression of many miRNAs. Accordingly, the role of miRNAs in the control of thyroid gene expression is evolving as an important mechanism in cancer. Herein, we present a protocol to examine the effects of miRNA-inhibitor delivery as a therapeutic modality in thyroid cancer using human tumor xenograft and orthotopic mouse models. After engineering stable thyroid tumoral cells expressing GFP and luciferase, cells are injected into nude mice to develop tumors, which can be followed by bioluminescence. The in vivo inhibition of a miRNA can reduce tumor growth and upregulate miRNA gene targets. This method can be used to assess the importance of a determined miRNA in vivo, in addition to identifying new therapeutic targets.

This protocol describes xenograft and orthotopic mouse models of human thyroid tumorigenesis as a platform to test microRNA-based inhibitor treatments. This approach is ideal to study the function of non-coding RNAs and their potential as new therapeutic targets.

MicroRNAs (miRNAs) are important regulators of gene expression through their ability to destabilize mRNA and inhibit translation of target mRNAs. An ...

Studying Triple Negative Breast Cancer Using Orthotopic Breast Cancer Model

Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype with limited therapeutic options. When compared to patients with less aggressive breast tumors, the 5-year survival rate of TNBC patients is 77% due to their characteristic drug-resistant phenotype and metastatic burden. Toward this end, murine models have been established aimed at identifying novel therapeutic strategies limiting TNBC tumor growth and metastatic spread. This work describes a practical guide for the TNBC orthotopic model where MDA-MB-231 breast cancer cells suspended in a basement membrane matrix are implanted in the fourth mammary fat pad, which closely mimics the cancer cell behavior in humans. Measurement of tumors by caliper, lung metastasis assessment via in vivo and ex vivo imaging, and molecular detection are discussed. This model provides an excellent platform to study therapeutic efficacy and is especially suitable for the study of the interaction between the primary tumor and distal metastatic sites.

This work presets an advanced protocol to accurately assess tumor loading by detection of green fluorescent protein and bioluminescence signals as well as the integration of quantitative molecular detection technique.

Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype with limited therapeutic options. When compared to patients with less ...

Combined Use of Tail Vein Metastasis Assays and Real-Time In Vivo Imaging to Quantify Breast Cancer Metastatic Colonization and Burden in the Lungs

Metastasis is the main cause of cancer-related deaths and there are limited therapeutic options for patients with metastatic disease. The identification and testing of novel therapeutic targets that will facilitate the development of better treatments for metastatic disease requires preclinical in vivo models. Demonstrated here is a syngeneic mouse model for assaying breast cancer metastatic colonization and subsequent growth. Metastatic cancer cells are stably transduced with viral vectors encoding firefly luciferase and ZsGreen proteins. Candidate genes are then stably manipulated in luciferase/ZsGreen-expressing cancer cells and then the cells are injected into mice via the lateral tail vein to assay metastatic colonization and growth. An in vivo imaging device is then used to measure the bioluminescence or fluorescence of the tumor cells in the living animals to quantify changes in metastatic burden over time. The expression of the fluorescent protein allows the number and size of metastases in the lungs to be quantified at the end of the experiment without the need for sectioning or histological staining. This approach offers a relatively quick and easy way to test the role of candidate genes in metastatic colonization and growth, and provides a great deal more information than traditional tail vein metastasis assays. Using this approach, we show that simultaneous knockdown of Yes associated protein (YAP) and transcriptional co-activator with a PDZ-binding motif (TAZ) in breast cancer cells leads to reduced metastatic burden in the lungs and that this reduced burden is the result of significantly impaired metastatic colonization and reduced growth of metastases.

The described approach combines experimental tail vein metastasis assays with in vivo live animal imaging to allow real-time monitoring of breast cancer metastasis formation and growth in addition to the quantification of metastasis number and size in the lungs.

Metastasis is the main cause of cancer-related deaths and there are limited therapeutic options for patients with metastatic disease. The identification ...

Orthotopic Transplantation of Breast Tumors as Preclinical Models for Breast Cancer

Preclinical models that faithfully recapitulate tumor heterogeneity and therapeutic response are critical for translational breast cancer research. Immortalized cell lines are easy to grow and genetically modify to study molecular mechanisms, yet the selective pressure from cell culture often leads to genetic and epigenetic alterations over time. Patient-derived xenograft (PDX) models faithfully recapitulate the heterogeneity and drug response of human breast tumors. PDX models exhibit a relatively short latency after orthotopic transplantation that facilitates the investigation of breast tumor biology and drug response. The transplantable genetically engineered mouse models allow the study of breast tumor immunity. The current protocol describes the method to orthotopically transplant breast tumor fragments into the mammary fat pad followed by drug treatments. These preclinical models provide valuable approaches to investigate breast tumor biology, drug response, biomarker discovery and mechanisms of drug resistance.

Patient-derived xenograft (PDX) models and transplantable genetically engineered mouse models faithfully recapitulate human disease and are preferred models for basic and translational breast cancer research. Here, a method is described to orthotopically transplant breast tumor fragments into the mammary fat pad to study tumor biology and evaluate drug response.

Preclinical models that faithfully recapitulate tumor heterogeneity and therapeutic response are critical for translational breast cancer research. ...