Research at SNU is supported by the National Research Foundation (NRF) by the MEST of Korea for Tumor Microenvironment Global Core Research Center (GCRC) grant, [grant number 2011-0030001]; by the Seoul National University Research Grant and by Brain Korea (BK21) PLUS program.

1. Colony Formation Assays
<ol>
	<li>Culture A549 cells at a concentration of 20,000 cells/cm2 in 15 mL of RPMI1640 cell culture medium supplemented with 10% FBS (Fetal Bovine Serum) and 1% antibiotics in a 75 cm2 flask in a CO2 incubator at 37&#160;&#176;C and 5% CO2.</li>
	<li>On the day of the experiment, determine the cell concentration by using a hemocytometer. Collect 50,000 cells by centrifugation at 400 x g for 7 min in a 1.5 mL microcentrifuge tube and re-suspend cells in 100 &#181;L of 1x sterile PBS (Phosphate Buffered Saline) in 1.5 mL tubes.</li>
	<li>Dispense 1.1 mL of semi-solid methylcellulose-based medium (MCBM) in 15 mL tubes with a multipipette. Prepare one tube for each condition.</li>
	<li>Add 110 &#181;L of FBS to 1.1 mL of MCBM using a P200 micropipette.</li>
	<li>Seeds cells at 1,000 cells/mL. Collect 2.4 &#181;L of cell suspension from the stock solution (50,000 cells in 100 &#181;L of 1x PBS) using a P2 micropipette and add to 1.1 mL of MCBM supplemented with 10% FBS.</li>
	<li>After adding the cells, vortex the tubes for 1 min, holding them vertically at the highest speed to mix MCBM and cells well.</li>
	<li>Add test compounds (OT48 alone or in combination with A1210477). Prepare a separate tube as a control for the solvent used (here dimethyl sulfoxide (DMSO)). Depending on the concentration of the compounds and the volume added for each condition, the solvent control will include the highest concentration of solvent used for the dilutions of the test compound, to assess for adverse effects caused by the solvent.</li>
	<li>Vortex tubes for 1 minute.</li>
	<li>For each assay, add 1 mL of the mixture with a P1000 micropipette to the center well of a 12-well cell culture plate.</li>
	<li>Fill empty wells with 1 mL of sterile water or 1x PBS to stabilize humidity.</li>
	<li>Incubate culture plates for 10 days in an incubator at 37&#160;&#176;C and 5% CO2.</li>
	<li>After 10 days of incubation, add 200 &#181;L of an MTT (methylthiazolyldiphenyl-tetrazolium bromide) stock solution (5 mg/mL) to each well to reach a final concentration of 1 mg/mL.</li>
	<li>Incubate 10 min in an incubator at 37&#160;&#176;C and 5% CO2. Viable colonies will turn violet.</li>
	<li>Capture the image using a digital camera using the white background plate (LAS white dia tray). Use the following settings: Method, digitize; Exposure type, precision; Exposure time, manual, 1 second; Sensitivity/resolution, high resolution. Save the image in tiff format.</li>
	<li>Quantify viable colonies by using ImageJ software. Select menu &#34;Image | Type | 8 bit&#34;. Select menu &#34;Adjust | Threshold&#34;. Set threshold to control and keep constant for all conditions; Select menu &#34;Analyze | Analyze Particles&#34;. Save data and analyze with a statistics software for graphical representation.</li>
</ol>
2. Spheroid Formation Assay
<ol>
	<li>Culture A549 cells at a concentration of 20,000 cells/cm2 in 75 cm2 flasks with 15 mL of RPMI 1640 medium supplemented with 10% FBS and 1% antibiotics.</li>
	<li>On the day of the experiment, prepare a 96 well U-bottom plate.</li>
	<li>Plate 10,000 cells into a well which already contains the compound of interest (here 50 &#181;M of OT48 and/or 20 &#181;M of A1210477). Adjust the final volume to 100 &#181;L of cell culture medium. The number of cells that form uniform spheroids with an intact outer boundary is considered adequate to form spheroids.</li>
	<li>Incubate for 3 days in an incubator at 37&#160;&#176;C and at 5% CO2.</li>
	<li>After 3 days of incubation, capture images of the spheroids using a light microscope with 4x magnification.</li>
</ol>
3. Zebrafish Xenograft Assay
NOTE: This technical approach is visualized as a schematic (Figure 1).
<ol>
	<li>Preparation of stock reagents
	<ol>
		<li>Prepare 1 L of 30x Danieau&#8217;s solution: 1740 mM NaCl, 21 mM KCl, 12 mM MgSO4&#8729;7H2O, 18 mM Ca(NO3)2, and 150 mM HEPES. Adjust to the pH of the buffer to 7.6 using a pH meter.</li>
		<li>Prepare 1% (50x) tricaine solution: Dissolve 20 mg of ethyl 3-aminobenzoate methanesulfonate (tricaine) in 2 mL of distilled water.</li>
		<li>Prepare 1% phenol Red-PBS solution: Add 2 &#181;L of Phenol Red sodium salt solution to 198 &#181;L of sterilized PBS solution in a 1.5 &#181;L tube.</li>
		<li>Prepare 3% methylcellulose: Add 3 g of methylcellulose to 100 mL of 1x Danieau&#8217;s solution.</li>
	</ol>
	</li>
	<li>Zebrafish egg production and incubation
	<ol>
		<li>Separate one female and one male zebrafish in a partition tank filled with UV-sterilized and filtered tap water at 28.5&#160;&#176;C in the dark. After 24 h of separation, mix fish of both genders to initiate mating. Transfer fertilized eggs from the mating tank to a Petri dish containing 5 mL of fresh Danieau&#8217;s solution.</li>
		<li>Wash eggs three times with 5 mL of Danieau&#8217;s solution. For the washing, carefully aspirate the eggs with a pipette and transfer to 5 mL of fresh solution. Incubate for 8 h at 28.5&#160;&#176;C.
		<ol>
			<li>After 8 h of incubation in Danieau&#39;s solution, change to Danieau&#39;s solution containing 0.03% 1-phenyl-2-thiourea (PTU) to inhibit pigmentation. Sort out opaque eggs (unfertilized or containing undeveloped embryos) to prevent contamination.</li>
		</ol>
		</li>
	</ol>
	</li>
	<li>Embryo dechorionation
	<ol>
		<li>24 h post fertilization (hpf), dechorionate zebrafish embryos using sharp forceps. Incubate hatching embryos in Danieau&#8217;s solution with 0.03% PTU at 28.5&#160;&#176;C until 48 hpf.</li>
	</ol>
	</li>
	<li>Compound-treated cell preparation
	<ol>
		<li>Seed A549 cells at 20,000 cells/cm2 in 25 cm2 culture flasks. After 24 h of seeding, add compounds (here OT48 at 50 &#181;M and and/or A1210477 at 20 &#181;M) for 24 h in an incubator at 37&#160;&#176;C and 5% CO2. Set up the treatment time for each compound to maintain the viability of the cells but to commit them towards cell death. This time point needs to be individually set up based on cell viability, morphology and molecular markers.</li>
		<li>2 h before the end of the treatment, stain cells with 4 &#181;M of fluorescent cell tracker dye CM-Dil at 37&#160;&#176;C and 5% CO2. After 2 h of incubation, trypsinize cells with 0.05% trypsin-EDTA, and dilute 106 cells in 50 &#181;L of phenol Red-PBS solution prior to injection.</li>
	</ol>
	</li>
	<li>Micro-injection of cancer cells for xenograft formation
	<ol>
		<li>Anesthetize zebrafish in a 0.02% tricaine solution for 5 min until they settle down on an agar plate.</li>
		<li>Pull a 1.0 mm (outside diameter (OD) glass capillary) by a micropipette puller (Program settings: P: 300, Heat: 260, Pull: 60, VEL: 50, and Time: 200). Cut the microcapillary with a syringe to produce a sharp edge. Load microcapillaries with 20 &#181;L of cell/phenol Red-PBS solution. Set injection pressure and time to dispense 2 nL per injection.</li>
		<li>Inject 100&#8211;200 cells into the yolk sac by injecting 6 to 10 nL via 3 to 5 injections. After injection, allow fish to recover for 10 to 30 min in 5 mL of fresh Danieau&#8217;s solution containing PTU solution. Dispatch fish in 24-well plates with 1 mL of Danieau&#39;s solution containing PTU solution are and incubate for 72 h at 28.5&#160;&#176;C.</li>
		<li>After 72 h of incubation, anesthetize fish in a 0.02% tricaine solution and immobilize on a glass slide with a drop of 3% methylcellulose. Take 5x pictures by fluorescence microscopy at a wavelength of 620 to 750 nm.</li>
		<li>Quantify the size of fluorescent tumors by ImageJ software. Select menu &#34;Analyze | Measure&#34;. Save values corresponding to the fluorescent signal and analyze with a statistics software for graphical representation.</li>
	</ol>
	</li>
</ol>

<ol>
	<li>Giancotti, F. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deregulation+of+cell+signaling+in+cancer.">Deregulation of cell signaling in cancer.</a> FEBS Letters. 588 (16), 2558-2570 (2014).</li><li>Knowlton, S., Onal, S., Yu, C. H., Zhao, J. J., Tasoglu, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bioprinting+for+cancer+research.">Bioprinting for cancer research.</a> Trends in Biotechnology. 33 (9), 504-513 (2015).</li><li>Santo, V. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drug+screening+in+3D+in+vitro+tumor+models:+overcoming+current+pitfalls+of+efficacy+read-outs.">Drug screening in 3D in vitro tumor models: overcoming current pitfalls of efficacy read-outs.</a> Biotechnology Journal. 12 (1), (2017).</li><li>Tanner, K., Gottesman, M. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Beyond+3D+culture+models+of+cancer.">Beyond 3D culture models of cancer.</a> Science Translational Medicine. 7 (283), 283ps289 (2015).</li><li>Haycock, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D+cell+culture:+a+review+of+current+approaches+and+techniques.">3D cell culture: a review of current approaches and techniques.</a> Methods in Molecular Biology. 695, 1-15 (2011).</li><li>Talhi, O., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bis(4-hydroxy-2H-chromen-2-one):+synthesis+and+effects+on+leukemic+cell+lines+proliferation+and+NF-kappaB+regulation.">Bis(4-hydroxy-2H-chromen-2-one): synthesis and effects on leukemic cell lines proliferation and NF-kappaB regulation.</a> Bioorganic and Medicinal Chemistry. 22 (11), 3008-3015 (2014).</li><li>Franken, N. A., Rodermond, H. M., Stap, J., Haveman, J., van Bree, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clonogenic+assay+of+cells+in+vitro.">Clonogenic assay of cells in vitro.</a> Nature Protocols. 1 (5), 2315-2319 (2006).</li><li>Katt, M. E., Placone, A. L., Wong, A. D., Xu, Z. S., Searson, 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=In+Vitro+Tumor+Models:+Advantages,+Disadvantages,+Variables,+and+Selecting+the+Right+Platform.">In Vitro Tumor Models: Advantages, Disadvantages, Variables, and Selecting the Right Platform.</a> Frontiers in Bioengineering and Biotechnology. 4, 12 (2016).</li><li>Lee, J. 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=Cytostatic+hydroxycoumarin+OT52+induces+ER/Golgi+stress+and+STAT3+inhibition+triggering+non-canonical+cell+death+and+synergy+with+BH3+mimetics+in+lung+cancer.">Cytostatic hydroxycoumarin OT52 induces ER/Golgi stress and STAT3 inhibition triggering non-canonical cell death and synergy with BH3 mimetics in lung cancer.</a> Cancer Letters. 416, 94-108 (2018).</li><li>Rotem, 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=Alternative+to+the+soft-agar+assay+that+permits+high-throughput+drug+and+genetic+screens+for+cellular+transformation.">Alternative to the soft-agar assay that permits high-throughput drug and genetic screens for cellular transformation.</a> Proceedings of the National Academy of Sciences of the United States of America. 112 (18), 5708-5713 (2015).</li><li>Spoerri, L., Beaumont, K. A., Anfosso, A., Haass, N. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Real-Time+Cell+Cycle+Imaging+in+a+3D+Cell+Culture+Model+of+Melanoma.">Real-Time Cell Cycle Imaging in a 3D Cell Culture Model of Melanoma.</a> Methods in Molecular Biology. 1612, 401-416 (2017).</li><li>Beaumont, K. A., Anfosso, A., Ahmed, F., Weninger, W., Haass, N. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging-+and+Flow+Cytometry-based+Analysis+of+Cell+Position+and+the+Cell+Cycle+in+3D+Melanoma+Spheroids.">Imaging- and Flow Cytometry-based Analysis of Cell Position and the Cell Cycle in 3D Melanoma Spheroids.</a> Journal of Visualized Experiments. (106), e53486 (2015).</li><li>Lovitt, C. J., Shelper, T. B., Avery, V. 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The authors have nothing to disclose.

The rates of colony formation obtained with MCBM depends on the cell type. Usually, for non-adherent cells, the number of colonies is much higher compared to adherent cells. We observed that A549 cells formed 30 to 40 colonies after 10 days. Previously we have reported for different leukemia cells that number of colonies is between 200 to 2509. Our results showed that OT48 alone did not produce a significant decrease of the number of colonies alone. However, in combination with BH3 mimetic A121047...

Cancer is caused by cellular mutations and as a consequence biochemical signaling pathways are disrupted triggering uncontrolled cell division and resistance to cell death. Tumors interfere with physiological functions of digestive, nervous, circulatory systems and subsequently neighboring tissues1. Despite extensive research efforts, cancer remains the most prevalent life-threatening disease in the world2. Precision medicine has been recognized as the foundation of future cancer therapeutics. New molecular entities are tested routinely in combination with existing drugs to improve clinical outcome.
However, one of the significant limitations associated with the development of new efficient targeted therapies is the failure of commonly used assays to simulate the exact biological outcome of drug exposure3. Cancer drug discovery still mostly relies on testing the efficacy of therapeutic agents in cancer cell lines cultured in 2D monolayer cultures, which are difficult to validate in clinical trials4. Therefore, there is a growing interest to develop better cancer models that better mimic the native features of tumors in vivo5. In recent years, an increasing interest in 3D culture models resulted in the development of improved methodologies to produce 3D tumor models5.
Here, we present an approach with three different 3D cell culture techniques allowing to improve the understanding of the potency of the hydroxycoumarin OT486 in combination with BH3 mimetics before more in depth in vivo assays. Our method consists of combining colony and SFAs with an in vivo tumor formation test based on a zebrafish model to further validate the efficacy of the combination of OT48 and BH3 mimetics in lung cancer cells and monitor cancer progression in a living organism.
Colony formation assays are routinely used to assess efficacy of anticancer agents for both solid as well as hematopoietic cancers. The assay determines the ability of a cell to proliferate indefinitely and form colonies7. The effect of an anticancer agent on the colony forming ability of cells is determined by decrease of the number and/or size of the colonies.
Spheroids represent in vitro tumor models and serve as a low-cost screening platform for anticancer agents. Spheroids are aggregates of cells growing in suspension or embedded in a 3D matrix. This approach is widely used for drug screening and studies of tumor growth, proliferation and immune interaction8.
To fully understand the properties of a new drug, it is essential to conduct in vivo experiments on rodents. However, this conventional method is expensive and time consuming. In recent years, zebrafish (Danio rerio) became a widely studied laboratory organism that is cheaper and faster to raise. Tumors developed in the zebrafish represent a 3D cell culture approach but within the in vivo setting of a vertebrate9.
Altogether, we use here three different 3D culture approaches including CFAs, SFAs and zebrafish in vivo tumor formation to demonstrate the anticancer capacity of hydroxycoumarin OT48 in a lung cancer A549 cell model in combination with BH3 mimetics.

<table>
	<tbody>
		<tr>
			<td>Materials required for colony formation assays</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>A549</td>
			<td>ATCC</td>
			<td>CCL-185</td>
			<td>37 C&#176;</td>
		</tr>
		<tr>
			<td>RPMI 1640</td>
			<td>Lonza</td>
			<td>30096</td>
			<td>4 C&#176;</td>
		</tr>
		<tr>
			<td>FBS</td>
			<td>Biowest</td>
			<td>S1520-500</td>
			<td>-20 C&#176;</td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin</td>
			<td>Lonza</td>
			<td>17-602E</td>
			<td>-20 C&#176;</td>
		</tr>
		<tr>
			<td>Cell culture flask T75</td>
			<td>SPL</td>
			<td>70075</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>PBS solution</td>
			<td>Hyclone</td>
			<td>SH30256.02</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>1.5ml tube</td>
			<td>Extragene</td>
			<td>Tube-170-C</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>15 ml tube</td>
			<td>Hyundai Micro</td>
			<td>H20015</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>12 well plate</td>
			<td>SPL</td>
			<td>30012</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>MethoCult</td>
			<td>StemCell technologies</td>
			<td>4230</td>
			<td>-20 C&#176;</td>
		</tr>
		<tr>
			<td>Thiazolyl Blue Tetrazolium Bromide (MTT powder)</td>
			<td>Sigma</td>
			<td>M5622</td>
			<td>4 C&#176;</td>
		</tr>
		<tr>
			<td>LAS4000</td>
			<td>GE Healthcare Technologies</td>
			<td></td>
			<td>RT</td>
		</tr>
		<tr>
			<td>Materials required for spheroid formation assay</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>A549</td>
			<td>ATCC</td>
			<td>CCL-185</td>
			<td>37 C&#176;</td>
		</tr>
		<tr>
			<td>RPMI 1640</td>
			<td>Lonza</td>
			<td>30096</td>
			<td>4 C&#176;</td>
		</tr>
		<tr>
			<td>FBS</td>
			<td>Biowest</td>
			<td>S1520-500</td>
			<td>-20 C&#176;</td>
		</tr>
		<tr>
			<td>Penicillin-streptomycin</td>
			<td>Lonza</td>
			<td>17-602E</td>
			<td>-20 C&#176;</td>
		</tr>
		<tr>
			<td>Cell culture flask T75</td>
			<td>SPL</td>
			<td>70075</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>PBS solution</td>
			<td>Hyclone</td>
			<td>SH30256.02</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>Trypsin-EDTA</td>
			<td>Gibco</td>
			<td>25-300-054</td>
			<td>4 C&#176;</td>
		</tr>
		<tr>
			<td>Corning costar ultra low attachemnt 96 well plate</td>
			<td>Corning</td>
			<td>3474</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>Microscopy</td>
			<td>Nikon</td>
			<td>Eclipse TS100</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>Materials required for zebrafish xenografts</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>A549</td>
			<td>ATCC</td>
			<td>CCL-185</td>
			<td>37 C&#176;</td>
		</tr>
		<tr>
			<td>RPMI 1640</td>
			<td>Lonza</td>
			<td>30096</td>
			<td>4 C&#176;</td>
		</tr>
		<tr>
			<td>FBS</td>
			<td>Biowest</td>
			<td>S1520-500</td>
			<td>-20 C&#176;</td>
		</tr>
		<tr>
			<td>Penicillin-streptomycin</td>
			<td>Lonza</td>
			<td>17-602E</td>
			<td>-20 C&#176;</td>
		</tr>
		<tr>
			<td>Cell culture flask T25</td>
			<td>SPL</td>
			<td>70025</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>Cell culture flask T75</td>
			<td>SPL</td>
			<td>70075</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>Cell culture flask T175</td>
			<td>SPL</td>
			<td>71175</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>1.5ml tube</td>
			<td>Extragene</td>
			<td>Tube-170-C</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>24 well plate</td>
			<td>SPL</td>
			<td>30024</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>Petridish</td>
			<td>SPL</td>
			<td>10100</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>PBS solution</td>
			<td>Hyclone</td>
			<td>SH30256.02</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>Trypsin-EDTA</td>
			<td>Gibco</td>
			<td>25-300-054</td>
			<td>4 C&#176;</td>
		</tr>
		<tr>
			<td>Sodium Chloride</td>
			<td>Sigma-Aldrich</td>
			<td>71382</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>Potassium chloride (KCL)</td>
			<td>Sigma-Aldrich</td>
			<td>P9541</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>Magnesium sulfate heptahydrate (MgSO4.7H2O)</td>
			<td>Sigma-Aldrich</td>
			<td>M2773</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>Calcium nitrate tetrahydrate (Ca(NO3)2)</td>
			<td>Sigma-Aldrich</td>
			<td>C1396</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>HEPES solution</td>
			<td>Sigma-Aldrich</td>
			<td>H0887</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>Ethyl 3-aminobenzoate methanesulfonate (Tricaine)</td>
			<td>Sigma-Aldrich</td>
			<td>E10521</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>Phenol Red solution</td>
			<td>Sigma-Aldrich</td>
			<td>P0290</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>Methylcellulose</td>
			<td>Sigma-Aldrich</td>
			<td>M0512</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>1-phenyl-2-thiourea (PTU)</td>
			<td>Sigma-Aldrich</td>
			<td>P7629</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>CM-Dil dye</td>
			<td>Invitrogen</td>
			<td>C7001</td>
			<td>-20 C&#176;</td>
		</tr>
		<tr>
			<td>Glass capillary</td>
			<td>World Precision Instruments</td>
			<td>TW 100F-4</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>Micropipette puller</td>
			<td>Shutter instrument, USA</td>
			<td>P-97</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>Micro injector</td>
			<td>World Precision Instruments</td>
			<td>PV820</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>Syringe</td>
			<td>KOVAX</td>
			<td>1ml</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>Micro loader</td>
			<td>Eppendorf</td>
			<td>5242956003</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>Glass slide</td>
			<td>Marienfeld</td>
			<td>HSU-1000612</td>
			<td>RT</td>
		</tr>
		<tr>
			<td>Fluorescence microscopy</td>
			<td>Leica</td>
			<td>DE/DM 5000B</td>
			<td>RT</td>
		</tr>
	</tbody>
</table>

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.

In Figure 2, lung cancer cell line A549 was seeded in MCBM to form colonies after treatment with OT48 alone or in combination with BH3 mimetic A1210477 at the indicated concentrations. The results showed that the combination significantly reduced number, size and total surface area of the colonies after 10 days of incubation.
In Figure 3, A549 cells were treated with OT...

Watch this Scientific Journal Video about Preclinical Assessment of the Bioactivity of the Anticancer Coumarin OT48 by Spheroids, Colony Formation Assays, and Zebrafish Xenografts at JoVE.com

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

preclinical-assessment-bioactivity-anticancer-coumarin-ot48-spheroids

Research

JoVE Journal

Cancer Research

8.3K Views.  Seoul National University. Here, we present the preclinical screening of anticancer coumarins using 3D culture and zebrafish.

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

Coculture Assays to Study Macrophage and Microglia Stimulation of Glioblastoma Invasion

Glioblastoma multiforme (grade IV glioma) is a very aggressive human cancer with a median survival of 1 year post diagnosis. Despite the increased understanding of the molecular events that give rise to glioblastomas, this cancer still remains highly refractory to conventional treatment. Surgical resection of high grade brain tumors is rarely complete due to the highly infiltrative nature of glioblastoma cells. Therapeutic approaches which attenuate glioblastoma cell invasion therefore is an attractive option. Our laboratory and others have shown that tumor associated macrophages and microglia (resident brain macrophages) strongly stimulate glioblastoma invasion. The protocol described in this paper is used to model glioblastoma-macrophage/microglia interaction using in vitro culture assays. This approach can greatly facilitate the development and/or discovery of drugs that disrupt the communication with the macrophages that enables this malignant behavior. We have established two robust coculture invasion assays where microglia/macrophages stimulate glioma cell invasion by 5 - 10 fold. Glioblastoma cells labelled with a fluorescent marker or constitutively expressing a fluorescent protein are plated without and with macrophages/microglia on matrix-coated polycarbonate chamber inserts or embedded in a three dimensional matrix. Cell invasion is assessed by using fluorescent microscopy to image and count only invasive cells on the underside of the filter. Using these assays, several pharmacological inhibitors (JNJ-28312141, PLX3397, Gefitinib, and Semapimod), have been identified which block macrophage/microglia stimulated glioblastoma invasion.

Understanding the malignant behavior of cancer requires creating accurate models of how tumor cells interact with components of the tumor microenvironment, such as macrophages. Here we describe two methods to study glioblastoma cell interaction with tumor associated macrophages and microglia where the effect on glioblastoma invasion is assessed.

Glioblastoma multiforme (grade IV glioma) is a very aggressive human cancer with a median survival of 1 year post diagnosis. Despite the increased ...

A Syngeneic Mouse Model of Metastatic Renal Cell Carcinoma for Quantitative and Longitudinal Assessment of Preclinical Therapies

Renal cell carcinoma (RCC) affects &#62; 60,000 people in the United States annually, and ~ 30% of RCC patients have multiple metastases at the time of diagnosis. Metastatic RCC (mRCC) is incurable, with a median survival time of only 18 months. Immune-based interventions (e.g., interferon (IFN) and interleukin (IL)-2) induce durable responses in a fraction of mRCC patients, and multikinase inhibitors (e.g., sunitinib or sorafenib) or anti-VEGF receptor monoclonal antibodies (mAb) are largely palliative, as complete remissions are rare. Such shortcomings in current therapies for mRCC patients provide the rationale for the development of novel treatment protocols. A key component in the preclinical testing of new therapies for mRCC is a suitable animal model. Beneficial features that recapitulate the human condition include a primary renal tumor, renal tumor metastases, and an intact immune system to investigate any therapy-driven immune effector responses and the formation of tumor-induced immunosuppressive factors. This report describes an orthotopic mRCC mouse model that has all of these features. We describe an intrarenal implantation technique using the mouse renal adenocarcinoma cell line Renca, followed by the assessment of tumor growth in the kidney (primary site) and lungs (metastatic site).

Implementation of an orthotopic model of renal cell carcinoma in immunocompetent mice affords the investigator a clinically-relevant system defined by the presence of a primary renal tumor and lung metastases in the same animal. This system can be used to preclinically test a variety of treatments in vivo.

Renal cell carcinoma (RCC) affects &#62; 60,000 people in the United States annually, and ~ 30% of RCC patients have multiple metastases at the time of ...

Immunofluorescence Microscopy of &#947;H2AX and 53BP1 for Analyzing the Formation and Repair of DNA Double-strand Breaks

DNA double-strand breaks (DSB) are serious DNA lesions. Analysis of the formation and repair of DSB is relevant in a broad spectrum of research areas including genome integrity, genotoxicity, radiation biology, aging, cancer, and drug development. In response to DSB, the histone H2AX is phosphorylated at Serine 139 in a region of several megabase pairs forming discrete nuclear foci detectable by immunofluorescence microscopy. In addition, 53BP1 (p53 binding protein 1) is another important DSB-responsive protein promoting repair of DSB by nonhomologous end-joining while preventing homologous recombination. According to the specific functions of &#947;H2AX and 53BP1, the combined analysis of &#947;H2AX and 53BP1 by immunofluorescence microscopy may be a reasonable approach for a detailed analysis of DSB. This manuscript provides a step-by-step protocol supplemented with methodical notes for performing the technique. Specifically, the influence of the cell cycle on &#947;H2AX foci patterns is demonstrated in normal fibroblasts of the cell line NHDF. Further, the value of the &#947;H2AX foci as a biomarker is depicted in x-ray irradiated lymphocytes of a healthy individual. Finally, genetic instability is investigated in CD34+ cells of a patient with acute myeloid leukemia by immunofluorescence microscopy of &#947;H2AX and 53BP1.

This manuscript provides a protocol for the analysis of DNA double-strand breaks by immunofluorescence microscopy of &#947;H2AX and 53BP1.

DNA double-strand breaks (DSB) are serious DNA lesions. Analysis of the formation and repair of DSB is relevant in a broad spectrum of research areas ...

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 ...

Potentiation of Anticancer Antibody Efficacy by Antineoplastic Drugs: Detection of Antibody-drug Synergism Using the Combination Index Equation

Potentiation of hostile monoclonal antibodies (mAb) by chemotherapeutic agents constitutes a valuable strategy for designing effective and safer therapy against cancer. Here we provide a protocol to identify a rational combination at the preclinical step. First, we describe a cell-based assay to assess the synergism between anticancer mAb and cytotoxic drugs, that uses the combination index equation of Chou and Talalay1. This includes the measurement of tumor cell drug- and antibody-sensitivity using an MTT assay, followed by an automated computer analysis to calculate the combination index (CI) values. CI values of &lt;1 indicate synergism between tested mAbs and cytotoxic agents1. To corroborate the in vitro findings in vivo, we further describe a method to assess the combination regimen efficacy in a xenograft tumor model. In this model, the combined regimen significantly delays tumor growth, which results in a significant extended survival in comparison to single-agent controls. Importantly, the in vivo experimentation reveals that the combination regimen is well tolerated. This protocol allows the effective evaluation of anticancer drug combinations in preclinical models and the identification of rational combination to evaluate in clinical trials.

This protocol describes how to assess synergism between an anticancer antibody and antineoplastic drugs in preclinical models by using the combination index equation of Chou and Talalay.

Potentiation of hostile monoclonal antibodies (mAb) by chemotherapeutic agents constitutes a valuable strategy for designing effective and safer therapy ...

In Vivo Imaging and Quantitation of the Host Angiogenic Response in Zebrafish Tumor Xenografts

Tumor angiogenesis is a key target of anti-cancer therapy and this method has been developed to provide a new model to study this process in vivo. A zebrafish xenograft is created by implanting mammalian tumor cells into the perivitelline space of two days-post-fertilization zebrafish embryos, followed by measuring the extent of the angiogenic response observed at an experimental endpoint up to two days post-implantation. The key advantage to this method is the ability to accurately quantitate the zebrafish host angiogenic response to the graft. This enables detailed examination of the molecular mechanisms as well as the host vs tumor contribution to the angiogenic response. The xenografted embryos can be subjected to a variety of treatments, such as incubation with potential anti-angiogenesis drugs, in order to investigate strategies to inhibit tumor angiogenesis. The angiogenic response can also be live-imaged in order to examine more dynamic cellular processes. The relatively undemanding experimental technique, cheap maintenance costs of zebrafish and short experimental timeline make this model especially useful for the development of strategies to manipulate tumor angiogenesis.

The aim of this method is to generate an in vivo model of tumor angiogenesis by xenografting mammalian tumor cells into a zebrafish embryo that has fluorescently-labelled blood vessels. By imaging the xenograft and associated vessels, a quantitative measurement of the angiogenic response can be obtained.

Tumor angiogenesis is a key target of anti-cancer therapy and this method has been developed to provide a new model to study this process in vivo. A ...

Enhanced Viability for Ex vivo 3D Hydrogel Cultures of Patient-Derived Xenografts in a Perfused Microfluidic Platform

Patient-derived xenografts (PDX), generated when resected patient tumor tissue is engrafted directly into immunocompromised mice, remain biologically stable, thereby preserving molecular, genetic, and histological features, as well as heterogeneity of the original tumor. However, using these models to perform a multitude of experiments, including drug screening, is prohibitive both in terms of cost and time. Three-dimensional (3D) culture systems are widely viewed as platforms in which cancer cells retain their biological integrity through biochemical interactions, morphology, and architecture. Our team has extensive experience culturing PDX cells in vitro using 3D matrices composed of hyaluronic acid (HA). In order to separate mouse fibroblast stromal cells associated with PDXs, we use rotation culture, where stromal cells adhere to the surface of tissue culture-treated plates while dissociated PDX tumor cells float and self-associate into multicellular clusters. Also floating in the supernatant are single, often dead cells, which present a challenge in collecting viable PDX clusters for downstream encapsulation into hydrogels for 3D cell culture. In order to separate these single cells from live cell clusters, we have employed density step gradient centrifugation. The protocol described here allows for the depletion of non-viable single cells from the healthy population of cell clusters that will be used for further in vitro experimentation. In our studies, we incorporate the 3D cultures in microfluidic plates which allow for media perfusion during culture. After assessing the resultant cultures using a fluorescent image-based viability assay of purified versus non-purified cells, our results show that this additional separation step substantially reduced the number of non-viable cells from our cultures.

This protocol demonstrates methods to enable extended in vitro culture of patient-derived xenografts (PDX). One step enhances overall viability of multicellular cluster cultures in 3D hydrogels, through straightforward removal of non-viable single cells. A secondary step demonstrates best practices for PDX culture in a perfused microfluidic platform.

Patient-derived xenografts (PDX), generated when resected patient tumor tissue is engrafted directly into immunocompromised mice, remain biologically ...

Drug Screening of Primary Patient Derived Tumor Xenografts in Zebrafish

Patient derived xenograft models are critical in defining how different cancers respond to drug treatment in an in vivo system. Mouse models are the standard in the field, but zebrafish have emerged as an alternative model with several advantages, including the ability for high-throughput and low-cost drug screening. Zebrafish also allow for in vivo drug screening with large replicate numbers that were previously only obtainable with in vitro systems. The ability to rapidly perform large scale drug screens may open up the possibility for personalized medicine with rapid translation of results back to clinic. Zebrafish xenograft models could also be used to rapidly screen for actionable mutations based on tumor response to targeted therapies or to identify new anti-cancer compounds from large libraries. The current major limitation in the field has been quantifying and automating the process so that drug screens can be done on a larger scale and be less labor-intensive. We have developed a workflow for xenografting primary patient samples into zebrafish larvae and performing large scale drug screens using a fluorescence microscope equipped imaging unit and automated sampler unit. This method allows for standardization and quantification of engrafted tumor area and response to drug treatment across large numbers of zebrafish larvae. Overall, this method is advantageous over traditional cell culture drug screening as it allows for growth of tumor cells in an in vivo environment throughout drug treatment, and is more practical and cost-effective than mice for large scale in vivo drug screens.

Zebrafish xenograft models allow for high-throughput drug screening and fluorescent imaging of human cancer cells in an in vivo microenvironment. We developed a workflow for large scale, automated drug screening on patient-derived leukemia samples in zebrafish using an automated fluorescence microscope equipped imaging unit.

Patient derived xenograft models are critical in defining how different cancers respond to drug treatment in an in vivo system. Mouse models are the ...

Generation of Zebrafish Larval Xenografts and Tumor Behavior Analysis

Zebrafish larval xenografts are being widely used for cancer research to perform in vivo and real-time studies of human cancer. The possibility of rapidly visualizing the response to anti-cancer therapies (chemo, radiotherapy, and biologicals), angiogenesis and metastasis with single cell resolution, places the zebrafish xenograft model as a top choice to develop preclinical studies.

The zebrafish larval xenograft assay presents several experimental advantages compared to other models, but probably the most striking is the reduction of size scale and consequently time. This reduction of scale allows single cell imaging, the use of a relatively low number of human cells (compatible with biopsies), medium-high-throughput drug screenings, but most importantly enables a significant reduction of the time of the assay. All these advantages make the zebrafish xenograft assay extremely attractive for future personalized medicine applications.

Many zebrafish xenograft protocols have been developed with a wide diversity of human tumors; however, a general and standardized protocol to efficiently generate zebrafish larval xenografts is still lacking. Here we provide a step-by-step protocol, with tips to generate xenografts and guidelines for tumor behavior analysis, whole-mount immunofluorescence, and confocal imaging quantification.

Here, we provide a step-by-step protocol, with tips to generate xenografts and guidelines for tumor behavior analysis, whole-mount immunofluorescence, and confocal imaging quantification.

Zebrafish larval xenografts are being widely used for cancer research to perform in vivo and real-time studies of human cancer. The possibility of rapidly ...

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.

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 ...