Name: preclinical assessment of the bioactivity of the anticancer coumarin ot48 by spheroids, colony formation assays, and zebrafish xenografts
Uploaded: 2018-06-26T13:00:00.000+00:00
Duration: 9 min 20 s
Description: 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

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>

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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>&lt;strong&gt;Materials required for colony formation assays&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>A549</td><td>ATCC</td><td>CCL-185</td><td>37 C&amp;deg;</td></tr><tr><td>RPMI 1640</td><td>Lonza</td><td>30096</td><td>4 C&amp;deg;</td></tr><tr><td>FBS</td><td>Biowest</td><td>S1520-500</td><td>-20 C&amp;deg;</td></tr><tr><td>Penicillin-Streptomycin</td><td>Lonza</td><td>17-602E</td><td>-20 C&amp;deg;</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&amp;deg;</td></tr><tr><td>Thiazolyl Blue Tetrazolium Bromide (MTT powder)</td><td>Sigma</td><td>M5622</td><td>4 C&amp;deg;</td></tr><tr><td>LAS4000</td><td>GE Healthcare Technologies</td><td></td><td>RT</td></tr><tr><td>&lt;strong&gt;Materials required for spheroid formation assay&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>A549</td><td>ATCC</td><td>CCL-185</td><td>37 C&amp;deg;</td></tr><tr><td>RPMI 1640</td><td>Lonza</td><td>30096</td><td>4 C&amp;deg;</td></tr><tr><td>FBS</td><td>Biowest</td><td>S1520-500</td><td>-20 C&amp;deg;</td></tr><tr><td>Penicillin-streptomycin</td><td>Lonza</td><td>17-602E</td><td>-20 C&amp;deg;</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&amp;deg;</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>&lt;strong&gt;Materials required for zebrafish xenografts&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>A549</td><td>ATCC</td><td>CCL-185</td><td>37 C&amp;deg;</td></tr><tr><td>RPMI 1640</td><td>Lonza</td><td>30096</td><td>4 C&amp;deg;</td></tr><tr><td>FBS</td><td>Biowest</td><td>S1520-500</td><td>-20 C&amp;deg;</td></tr><tr><td>Penicillin-streptomycin</td><td>Lonza</td><td>17-602E</td><td>-20 C&amp;deg;</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&amp;deg;</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&amp;deg;</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

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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

Testing the Vascular Invasive Ability of Cancer Cells in Zebrafish (Danio Rerio)

Cancer cell vascular invasion and extravasation is a hallmark of metastatic progression. Traditional in vitro models of cancer cell invasion of endothelia typically lack the fluid dynamics that invading cells are otherwise exposed to in vivo. However, in vivo systems such as mouse models, though more physiologically relevant, require longer experimental timescales and present unique challenges associated with monitoring and data analysis. Here we describe a zebrafish assay that seeks to bridge this technical gap by allowing for the rapid assessment of cancer cell vascular invasion and extravasation. The approach involves injecting fluorescent cancer cells into the precardiac sinus of transparent 2-day old zebrafish embryos whose vasculature is marked by a contrasting fluorescent reporter. Following injection, the cancer cells must survive in circulation and subsequently extravasate from vessels into tissues in the caudal region of the embryo. Extravasated cancer cells are efficiently identified and scored in live embryos via fluorescence imaging at a fixed timepoint. This technique can be modified to study intravasation and/or competition amongst a heterogeneous mixture of cancer cells by changing the injection site to the yolk sac. Together, these methods can evaluate a hallmark behavior of cancer cells and help uncover mechanisms indicative of malignant progression to the metastatic phenotype.

Testing the Vascular Invasive Ability of Cancer Cells in Zebrafish Danio Rerio

This method utilizes zebrafish embryos to efficiently test the vascular invasive ability of cancer cells. Fluorescent cancer cells are injected into the precardiac sinus or yolk sac of developing embryos. Cancer cell vascular invasion and extravasation is assessed via fluorescence microscopy of the tail region 24 to 96 hr later.

Cancer cell vascular invasion and extravasation is a hallmark of metastatic progression.  Traditional in vitro models of cancer cell invasion of ...

Screening for Melanoma Modifiers using a Zebrafish Autochthonous Tumor Model

Genomic studies of human cancers have yielded a wealth of information about genes that are altered in tumors1,2,3. A challenge arising from these studies is that many genes are altered, and it can be difficult to distinguish genetic alterations that drove tumorigenesis from that those arose incidentally during transformation. To draw this distinction it is beneficial to have an assay that can quantitatively measure the effect of an altered gene on tumor initiation and other processes that enable tumors to persist and disseminate. Here we present a rapid means to screen large numbers of candidate melanoma modifiers in zebrafish using an autochthonous tumor model4 that encompasses steps required for melanoma initiation and maintenance. A key reagent in this assay is the miniCoopR vector, which couples a wild-type copy of the mitfa melanocyte specification factor to a Gateway recombination cassette into which candidate melanoma genes can be recombined5. The miniCoopR vector has a mitfa rescuing minigene which contains the promoter, open reading frame and 3'-untranslated region of the wild-type mitfa gene. It allows us to make constructs using full-length open reading frames of candidate melanoma modifiers. These individual clones can then be injected into single cell Tg(mitfa:BRAFV600E);p53(lf);mitfa(lf)zebrafish embryos. The miniCoopR vector gets integrated by Tol2-mediated transgenesis6 and rescues melanocytes. Because they are physically coupled to the mitfa rescuing minigene, candidate genes are expressed in rescued melanocytes, some of which will transform and develop into tumors. The effect of a candidate gene on melanoma initiation and melanoma cell properties can be measured using melanoma-free survival curves, invasion assays, antibody staining and transplantation assays.

A rapid way to screen for melanoma modifiers using a zebrafish autochthonous tumor model is presented. It takes advantage of the miniCoopR vector which allows for expression of candidate melanoma genes in melanocytes. A method to obtain melanoma-free survival curves, an invasion assay, a protocol for antibody staining of scale melanocytes and a melanoma transplantation assay are described.

Genomic studies of  human cancers have yielded a wealth of information about genes that are altered  in tumors1,2,3. A challenge arising from these ...

Medicine

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 ...

Establishing 3-Dimensional Spheroids from Patient-Derived Tumor Samples and Evaluating their Sensitivity to Drugs

Despite remarkable advances in understanding tumor biology, the vast majority of oncology drug candidates entering clinical trials fail, often due to a lack of clinical efficacy. This high failure rate illuminates the inability of the current preclinical models to predict clinical efficacy, mainly due to their inadequacy in reflecting tumor heterogeneity and the tumor microenvironment. These limitations can be addressed with 3-dimensional (3D) culture models (spheroids) established from human tumor samples derived from individual patients. These 3D cultures represent real-world biology better than established cell lines that do not reflect tumor heterogeneity. Furthermore, 3D cultures are better than 2-dimensional (2D) culture models (monolayer structures) since they replicate elements of the tumor environment, such as hypoxia, necrosis, and cell adhesion, and preserve the natural cell shape and growth. In the present study, a method was developed for preparing primary cultures of cancer cells from individual patients that are 3D and grow in multicellular spheroids. The cells can be derived directly from patient tumors or patient-derived xenografts. The method is widely applicable to solid tumors (e.g., colon, breast, and lung) and is also cost-effective, as it can be performed in its entirety in a typical cancer research/cell biology lab without relying on specialized equipment. Herein, a protocol is presented for generating 3D tumor culture models (multicellular spheroids) from primary cancer cells and evaluating their sensitivity to drugs using two complementary approaches: a cell-viability assay (MTT) and microscopic examinations. These multicellular spheroids can be used to assess potential drug candidates, identify potential biomarkers or therapeutic targets, and investigate the mechanisms of response and resistance.

The present protocol describes generating 3D tumor culture models from primary cancer cells and evaluating their sensitivity to drugs using cell-viability assays and microscopic examinations.

Despite remarkable advances in understanding tumor biology, the vast majority of oncology drug candidates entering clinical trials fail, often due to a ...

Establishment of Zebrafish Patient-Derived Xenografts from Pancreatic Cancer for Chemosensitivity Testing

Cancer is one of the main causes of death worldwide, and the incidence of many types of cancer continues to increase. Much progress has been made in terms of screening, prevention, and treatment; however, preclinical models that predict the chemosensitivity profile of cancer patients are still lacking. To fill this gap, an in vivo patient-derived xenograft model was developed and validated. The model was based on zebrafish (Danio rerio) embryos at 2 days post fertilization, which were used as recipients of xenograft fragments of tumor tissue taken from a patient's surgical specimen. 
It is also worth noting that bioptic samples were not digested or disaggregated, in order to maintain the tumor microenvironment, which is crucial in terms of analyzing tumor behavior and the response to therapy. The protocol details a method for establishing zebrafish-based patient-derived xenografts (zPDXs) from primary solid tumor surgical resection. After screening by an anatomopathologist, the specimen is dissected using a scalpel blade. Necrotic tissue, vessels, or fatty tissue are removed and then chopped into 0.3 mm x 0.3 mm x 0.3 mm pieces. 
The pieces are then fluorescently labeled and xenotransplanted into the perivitelline space of zebrafish embryos. A large number of embryos can be processed at a low cost, enabling high-throughput in vivo analyses of the chemosensitivity of zPDXs to multiple anticancer drugs. Confocal images are routinely acquired to detect and quantify the apoptotic levels induced by chemotherapy treatment compared to the control group. The xenograft procedure has a significant time advantage, since it can be completed in a single day, providing a reasonable time window to carry out a therapeutic screening for co-clinical trials.

Preclinical models aim to advance the knowledge of cancer biology and predict treatment efficacy. This paper describes the generation of zebrafish-based patient-derived xenografts (zPDXs) with tumor tissue fragments. The zPDXs were treated with chemotherapy, the therapeutic effect of which was assessed in terms of cell apoptosis of the transplanted tissue.

Cancer is one of the main causes of death worldwide, and the incidence of many types of cancer continues to increase. Much progress has been made in terms ...

Utilizing Larval Zebrafish for Efficient In Vivo Tumor Studies

A Simple, Rapid, and Effective Method for Tumor Xenotransplantation Analysis in Transparent Zebrafish Embryos

In vivo studies of tumor behavior are a staple of cancer research; however, the use of mice presents significant challenges in cost and time. Here, we present larval zebrafish as a transplant model that has numerous advantages over murine models, including ease of handling, low expense, and short experimental duration. Moreover, the absence of an adaptive immune system during larval stages obviates the need to generate and use immunodeficient strains. While established protocols for xenotransplantation in zebrafish embryos exist, we present here an improved method involving embryo staging for faster transfer, survival analysis, and the use of flow cytometry to assess disease burden. Embryos are staged to facilitate rapid cell injection into the yolk of the larvae and cell marking to monitor the consistency of the injected cell bolus. After injection, embryo survival analysis is assessed up to 7 days post injection (dpi). Finally, disease burden is also assessed by marking transferred cells with a fluorescent protein and analysis by flow cytometry. Flow cytometry is enabled by a standardized method of preparing cell suspensions from zebrafish embryos, which could also be used in establishing the primary culture of zebrafish cells. In summary, the procedure described here allows a more rapid assessment of the behavior of tumor cells in vivo with larger numbers of animals per study arm and in a more cost-effective manner.

Author Spotlight: Advancing Cancer Therapeutics Using Tumor Xenotransplantation in Zebrafish

We describe a protocol for xenotransplantation into the yolk of transparent zebrafish embryos that is optimized by a simple, rapid staging method. Post-injection analyses include survival and assessing the disease burden of xenotransplanted cells by flow cytometry.

In vivo studies of tumor behavior are a staple of cancer research; however, the use of mice presents significant challenges in cost and time. Here, we ...

Rapid Evaluation of Toxicity of Chemical Compounds Using Zebrafish Embryos

The zebrafish is a widely used vertebrate model organism for the disease and phenotype-based drug discovery. The zebrafish generates many offspring, has transparent embryos and rapid external development. Zebrafish embryos can, therefore, also be used for the rapid evaluation of toxicity of the drugs that are precious and available in small quantities. In the present article, a method for the efficient screening of the toxicity of chemical compounds using 1-5-day post fertilization embryos is described. The embryos are monitored by stereomicroscope to investigate the phenotypic defects caused by the exposure to different concentrations of compounds. Half-maximal lethal concentrations (LC50) of the compounds are also determined. The present study required 3-6 mg of an inhibitor compound, and the whole experiment takes about 8-10 h to be completed by an individual in a laboratory having basic facilities. The current protocol is suitable for testing any compound to identify intolerable toxic or off-target effects of the compound in the early phase of drug discovery and to detect subtle toxic effects that may be missed in the cell culture or other animal models. The method reduces procedural delays and costs of drug development.

Zebrafish embryos are used for evaluating the toxicity of chemical compounds. They develop externally and are sensitive to chemicals, allowing detection of subtle phenotypic changes. The experiment only requires a small amount of compound, which is directly added to the plate containing embryos, making the testing system efficient and cost-effective.

The zebrafish is a widely used vertebrate model organism for the disease and phenotype-based drug discovery. The zebrafish generates many offspring, has ...

Zebrafish Xenograft Assay: A Method to Assess the Anti-cancer Efficacy of Therapeutics on Tumorigenicity in Zebrafish In Vivo

Source: Lee, J. Y et al.,<a href="https://www.jove.com/v/57490/preclinical-assessment-bioactivity-anticancer-coumarin-ot48-spheroids">Preclinical Assessment of the Bioactivity of the Anticancer Coumarin OT48 by Spheroids, Colony Formation Assays, and Zebrafish Xenografts.</a>&#160;J. Vis. Exp. (2018)
This video describes the zebrafish xenograft assay to assess in vivo tumor formation and study the effect of therapeutic agents.

Test ksenoprzeszczepu danio pręgowanego: metoda oceny skuteczności przeciwnowotworowej leków na rakotwórczość u danio pręgowanego in vivo

Source: Lee, J. Y et al.,Preclinical Assessment of the Bioactivity of the Anticancer Coumarin OT48 by Spheroids, Colony Formation Assays, and Zebrafish ...

JoVE Encyclopedia of Experiments

Lung Cancer

In vivo study

Zebrafish Patient-Derived Xenograft (zPDX): A Cancer Model

Source: Wang L. et. al., <a href="https://www.jove.com/v/59507/" target="_blank">Patient-derived Heterogeneous Xenograft Model of Pancreatic Cancer Using Zebrafish Larvae as Hosts for Comparative Drug Assessment</a>. J. Vis. Exp. (2019).
This video describes the technique to create a zebrafish patient derived xenograft model. In the sample protocol, we assess the efficiency of the drugs Gemcitabine and Navitoclax on the pancreatic tumor xenograft model.