Name: invasive behavior of human breast cancer cells in embryonic zebrafish
Uploaded: 2017-04-25T15:00:00
Description: Watch this Scientific Journal Video about Invasive Behavior of Human Breast Cancer Cells in Embryonic Zebrafish at JoVE.com

Studies on TGF-&#946; family members are supported by the Cancer Genomics Centre Netherlands. Sijia Liu and Jiang Ren are supported by the China Scholarship Council for 4 years of study at the University of Leiden. We thank Dr. Fred Miller (Barbara Ann Karmanos Cancer Institute, Detroit, MI, USA) for the MCF10A cell lines.

All research using the transgenic fluorescent zebrafish Tg (fli:EGFP) strain, which has enhanced green fluorescent protein (EGFP)-labeled vasculature20, including housing and experiments, was carried out according to the international guidelines and was approved by the local Institutional Committee for Animal Welfare (Dier Ethische Commissie (DEC) of the Leiden University Medical Center.
NOTE: As summarized in Figure 1, the protocol is roughly broken down into four steps: embryo collec...

<ol>
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Here, we described two methods to investigate the invasive behavior of breast cancer cells in Tg (fli1:EGFP) zebrafish embryos, with perivitelline space and Doc injections. By injecting cancer cells labeled with chemical dye or fluorescent protein into transgenic zebrafish embryos, the dynamic and spatial characteristics of invasion and metastasis can be clearly tracked in real-time at the single-cell or cluster level under a fluorescence microscope. In most cases, the rapid progression of metastasis in zebrafis...

Overt cancer metastasis in the clinic comprises a series of complex and multi-step events known as the &#34;metastatic cascade&#34;. The cascade has been extensively reviewed and can be dissected into successive steps: local invasion, intravasation, dissemination, arrest, extravasation, and colonization1,2. A better understanding of the pathogenesis of cancer metastasis and the development of potential treatment strategies in vivo require robust host models of cancer cell spread. Rodent models are well established and are widely used to evaluate metastasis3, but these approaches have low efficiency and ethical limitations and are costly as a forefront model to determine whether a particular manipulation could affect the metastatic phenotype. Other efficient, reliable, low-cost models are needed to quickly access the potential effects of (epi)genetic changes or pharmacological compounds. Due to their high genetic homology to humans and the transparency of their embryos zebrafish (Danio rerio) have emerged as an important vertebrate model and are being increasingly applied to the study of developmental processes, microbe-host interactions, human diseases, drug screening, etc.4. The cancer metastasis models established in zebrafish may provide an answer to the shortcomings of rodent models5,6.
Although spontaneous neoplasia is scarcely seen in wild zebrafish7, there are several longstanding techniques to induce the desired cancer in zebrafish. Carcinogen-induced gene mutations or signaling pathway activation can histologically and molecularly model carcinogenesis, mimicking human disease in zebrafish7,8,9. By taking advantage of diverse forward and reverse genetic manipulations of oncogenes or tumor suppressors, (transgenic) zebrafish have also enabled potential studies of cancer formation and maintenance6,10. The induced cancer models in zebrafish cover a broad spectrum, including digestive, reproductive, blood, nervous system, and epithelial6.
The utilization of zebrafish in cancer research has expanded recently due to the establishment of human tumor cell xenograft models in this organism. This was first reported with human metastatic melanoma cells that were successfully engrafted in zebrafish embryos at the blastula stage in 200511. Several independent laboratories have validated the feasibility of this pioneering work by introducing a diverse range of mammalian cancer cells lines into zebrafish at various sites and developmental stages5. For example, injections near the blastodisc and blastocyst of the blastula stage; injections into the yolk sac, perivitelline space, duct of Cuvier (Doc), and posterior cardinal vein of 6-h- to 5-day-old embryos; and injections into the peritoneal cavity of 30-day-old immunosuppressed larvae have been performed5,12. Additionally, allogeneic tumor transplantations were also reported in zebrafish12,13. One of the great advantages of using xenografts is that the engrafted cancer cells can be easily fluorescently labeled and distinguished from normal cells. Hence, investigations into the dynamic behaviors of microtumor formation14, cell invasion and metastasis15,16,17, tumor-induced angiogenesis15,18, and the interactions between cancer cells and host factors17 can be clearly visualized in the live fish body, especially when transgenic zebrafish lines are applied5.
Inspired by the high potential of zebrafish xenograft models to evaluate metastasis, we demonstrated the transvascular extravasation properties of different breast cancer cell lines in the tailfin area of Tg (fli:EGFP) zebrafish embryos through Doc injections16. The role of transforming growth factor-&#946; (TGF-&#946;)16 and bone morphogenetic protein (BMP)19 signaling pathways in pro-/anti-breast cancer cell invasion and metastasis were also investigated in this model. Moreover, we also recapitulated the intravasation ability of various breast cancer cell lines into circulation using xenograft zebrafish models with perivitelline space injections.
This article presents detailed protocols for zebrafish xenograft models based upon the injection of human breast cancer cells into the perivitelline space or Doc. Using high-resolution fluorescence imaging, we show the representative process of intravasation into blood vessels and the invasive behavior of different human breast cancer cells, which move from the blood vessels into the avascular tailfin area.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Agarose</td>
			<td>MP Biomedicals</td>
			<td>AGAF0500</td>
			<td></td>
		</tr>
		<tr>
			<td>Borosilicate glass capillary</td>
			<td>Harvard Apparatus</td>
			<td>300038</td>
			<td></td>
		</tr>
		<tr>
			<td>Cholera enterotoxin&#160;</td>
			<td>Calbiochem</td>
			<td>227035</td>
			<td></td>
		</tr>
		<tr>
			<td>Confocal microscope</td>
			<td>Leica</td>
			<td>SP5 STED</td>
			<td></td>
		</tr>
		<tr>
			<td>DMEM-high glucose media containing L-glutamine</td>
			<td>ThermoFisher Scientific</td>
			<td>11965092</td>
			<td></td>
		</tr>
		<tr>
			<td>DMEM/F-12 media containing L-glutamine</td>
			<td>ThermoFisher Scientific</td>
			<td>21041025</td>
			<td></td>
		</tr>
		<tr>
			<td>Dumont #5 forceps</td>
			<td>Fine Science Tools Inc</td>
			<td>11252-20</td>
			<td></td>
		</tr>
		<tr>
			<td>Epidermal growth factor</td>
			<td>Merck Millipore</td>
			<td>01-107</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal bovine serum&#160;</td>
			<td>ThermoFisher Scientific</td>
			<td>16140071</td>
			<td></td>
		</tr>
		<tr>
			<td>Fluorescent stereo microscope</td>
			<td>Leica</td>
			<td>M165 FC</td>
			<td></td>
		</tr>
		<tr>
			<td>HEK293T cell line</td>
			<td>American Type Culture Collection</td>
			<td>CRL-1573</td>
			<td></td>
		</tr>
		<tr>
			<td>Hydrocortisone</td>
			<td>SigmaAldrich</td>
			<td>227035</td>
			<td></td>
		</tr>
		<tr>
			<td>Horse serum</td>
			<td>ThermoFisher Scientific</td>
			<td>26050088</td>
			<td></td>
		</tr>
		<tr>
			<td>Insulin</td>
			<td>SigmaAldrich</td>
			<td>I-6634</td>
			<td></td>
		</tr>
		<tr>
			<td>MCF10A (M1) cell line</td>
			<td></td>
			<td></td>
			<td>Kindly provided by Dr. Fred Miller (Barbara Ann Karmanos Cancer Institute, Detroit, MI, USA)&#160;</td>
		</tr>
		<tr>
			<td>MCF10Aras (M2) cell line</td>
			<td></td>
			<td></td>
			<td>Kindly provided by Dr. Fred Miller (Barbara Ann Karmanos Cancer Institute, Detroit, MI, USA)&#160;</td>
		</tr>
		<tr>
			<td>MDA-MB-231 cell line</td>
			<td>American Type Culture Collection</td>
			<td>CRM-HTB-26</td>
			<td></td>
		</tr>
		<tr>
			<td>Manual micromanipulator&#160;</td>
			<td>World Precision Instruments</td>
			<td>M3301R</td>
			<td></td>
		</tr>
		<tr>
			<td>Micropipette puller</td>
			<td>Sutter Instruments</td>
			<td>P-97&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>Wide-tip Pasteur pipette (0,5-20 ul)</td>
			<td>Eppendorf</td>
			<td>F276456I</td>
			<td></td>
		</tr>
		<tr>
			<td>pCMV-VSVG plasmid</td>
			<td></td>
			<td></td>
			<td>Kindly provided by Prof. Dr. Rob Hoeben (Leiden University Medical Center, Leiden, The Netherlands)</td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin (10,000 U/mL)</td>
			<td>ThermoFisher Scientific</td>
			<td>15140122</td>
			<td></td>
		</tr>
		<tr>
			<td>PLV-mCherry plasmid</td>
			<td>Addgene</td>
			<td>36084</td>
			<td></td>
		</tr>
		<tr>
			<td>pMDLg-RRE (gag/pol) plasmid</td>
			<td></td>
			<td></td>
			<td>Kindly provided by Prof. Dr. Rob Houben (Leiden University Medical Center, Leiden, The Netherlands)</td>
		</tr>
		<tr>
			<td>Pneumatic picoPump</td>
			<td>World Precision Instruments</td>
			<td>SYS-PV820</td>
			<td></td>
		</tr>
		<tr>
			<td>Polybrene</td>
			<td>SigmaAldrich</td>
			<td>107689</td>
			<td></td>
		</tr>
		<tr>
			<td>Prism 4 software</td>
			<td>GraphPad Software</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>pRSV-REV plasmid</td>
			<td></td>
			<td></td>
			<td>Kindly provided by Prof. Dr. Rob Hoeben (Leiden University Medical Center, Leiden, The Netherlands)</td>
		</tr>
		<tr>
			<td>Stereo microscope</td>
			<td>Leica</td>
			<td>MZ16FA</td>
			<td></td>
		</tr>
		<tr>
			<td>Tg (fli:EGFP) zebrafish strain</td>
			<td></td>
			<td></td>
			<td>Kindly provided by Dr. Ewa Snaar-Jagalska (Institute of Biology, Leiden University, Leiden, The Netherlands)</td>
		</tr>
		<tr>
			<td>Tris-base&#160;</td>
			<td>SigmaAldrich</td>
			<td>11814273001</td>
			<td></td>
		</tr>
		<tr>
			<td>Tricaine (3-aminobenzoic acid)</td>
			<td>SigmaAldrich</td>
			<td>A-5040</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin-EDTA (0.5%)</td>
			<td>ThermoFisher Scientific</td>
			<td>15400054</td>
			<td></td>
		</tr>
		<tr>
			<td>Petri dishes, polystyrene (60 &#215; 15 mm)</td>
			<td>SigmaAldrich</td>
			<td>P5481-500EA</td>
			<td></td>
		</tr>
		<tr>
			<td>Polystyrene dish with glass bottom</td>
			<td>WillCo</td>
			<td>GWST-5040</td>
			<td></td>
		</tr>
	</tbody>
</table>

invasive behavior of human breast cancer cells in embryonic zebrafish

In many cases, cancer patients do not die of a primary tumor, but rather because of metastasis. Although numerous rodent models are available for studying cancer metastasis in vivo, other efficient, reliable, low-cost models are needed to quickly access the potential effects of (epi)genetic changes or pharmacological compounds. As such, we illustrate and explain the feasibility of xenograft models using human breast cancer cells injected into zebrafish embryos to support this goal. Under the microscope, fluorescent proteins or chemically labeled human breast cancer cells are transplanted into transgenic zebrafish embryos, Tg (fli:EGFP), at the perivitelline space or duct of Cuvier (Doc) 48 h after fertilization. Shortly afterwards, the temporal-spatial process of cancer cell invasion, dissemination, and metastasis in the living fish body is visualized under a fluorescent microscope. The models using different injection sites, i.e., perivitelline space or Doc are complementary to one another, reflecting the early stage (intravasation step) and late stage (extravasation step) of the multistep metastatic cascade of events. Moreover, peritumoral and intratumoral angiogenesis can be observed with the injection into the perivitelline space. The entire experimental period is no more than 8 days. These two models combine cell labeling, micro-transplantation, and fluorescence imaging techniques, enabling the rapid evaluation of cancer metastasis in response to genetic and pharmacological manipulations.

In the embryonic xenograft zebrafish model with a perivitelline space injection, the hematogenous dissemination of labeled cancer cells in the fish body is considered as active migration. This process can be detected and quantified under a fluorescent microscope, as described in the methods above. To illustrate this xenograft model, we followed the dissemination process of different breast cancer cell lines with known (or without) invasion/metastasis potential according to in vitro</e...

Watch this Scientific Journal Video about Invasive Behavior of Human Breast Cancer Cells in Embryonic Zebrafish at JoVE.com

Invasive Behavior of Human Breast Cancer Cells in Embryonic Zebrafish

Here, we describe xenograft zebrafish models using two different injection sites, i.e., perivitelline space and duct of Cuvier, to investigate the invasive behavior and to assess the intravasation and extravasation potential of human breast cancer cells, respectively.

In many cases, cancer patients do not die of a primary tumor, but rather because of metastasis. Although numerous rodent models are available for studying ...

The overall goal of this microinjection of human breast cancer cells into embryonic zebrafish is to investigate the invasive behavior and assess the metastatic potential of human breast cancer cells. This method can help to answer key questions regarding intravasation and extravasation to critical processes in cancer metastasis. The main advantage of this technique is that it provides an elegant, rapid, and cheap in vivo model to measure the ability of cancer cells to invade and metastasize.The implications of this technique extend towards the development of new pharmacological compounds with anti-metastatic activity. Though this measure can provide insight into cancer emission and the metastasis, it can also be applied to study some other phenomena, such as peritumoral angiogenesis and cancer cell dormancy. To begin, culture transduced human breast cancer MDA-MB-231 cells, breast epithelial MCF10A cells, and breast epithelial MCF10A-Ras cells in a T75 flask.Once the transduced cells reach 80%confluence, remove the medium from the T75 flask, wash the cells with phosphate-buffered saline, and detach the cells with 0.5%Trypsin-EDTA solution. Then neutralize the Trypsin with medium. Next, centrifuge the cells at 1, 000 RPM for five minutes to remove the medium, wash them with PBS, and centrifuge the sample one more time.After washing, resuspend the cells in approximately 200 microliters of PBS to obtain a suspension of no more than 1 x 10 to the eighth cells per milliliter. Store the cell suspension in four degrees Celsius for no longer than five hours. To prepare zebrafish embryos for implantation, incubate approximately 60 embryos in a petri dish filled with egg water, supplemented with 60 micrograms per milliliter of sea salts at 28 degrees Celsius.Then, using fine tweezers, remove the coriands from the embryos at 48 hours post-fertilization. To anesthetize the embryos for the implantation procedure, transfer them to a 40 microgram per milliliter solution of tricaine in egg water. Prior to the implantation, prepare injection needles.To do this, load a borosilicate microcapillary tube into a micro-pipette puller and pull the needle. Store the prepared needles in a needle-holder plate until needed. Aspirate 15 microliters of the prepared cell suspension into an injection needle.Next, attach the needle to a micromanipulator, and, using fine tweezers, break its tip to five to 10 microns. Adjust the pneumatic PICO pump and inject cells onto the petri dish pre-coated with sterile 1%agarose. Then, transfer approximately 10 anesthetized embryos at two to three days post-fertilization onto a flat injecting plate coated with 1%agarose.Arrange the position of the embryos with a hair loop tool so that they are oriented in the same direction. While injecting, manually adjust the injection plate position to place the embryos in a diagonal orientation, which is preferred for a precise needle insertion. Direct the needle tip at the injection site and gently insert it into the perivitelline space localized between the yolk sac and the paraderm of the zebrafish embryo.Lastly, inject approximately 400 tumor cells labeled with mCherry. Make sure not to rupture the yolk sac to avoid a misplaced implantation. To inject the cells into the duct of Cuvier, approach the vein from the dorsal side of the embryo with the needle kept at a 45-degree angle.Insert the needle at the starting point of the duct of Cuvier, localized dorsally to the point where the duct starts broadening over the yolk sac. Then, inject approximately 400 cells. Finally, transfer the injected zebrafish embryos to the egg water, and incubate them at 33 degrees Celsius until further analysis.To visualize metastasis, with a Pasteur pipette, transfer the injected zebrafish embryo to a glass-bottom polystyrene dish and remove excess egg water. Image the whole body of the embryo with a confocal microscope set to low magnification to obtain a general pattern of tumor cell dissemination. Use a 488 nanometer laser to visualize the zebrafish embryo vasculature, and a 543 nanometer laser to visualize implanted tumor cells labeled with red fluorescent marker.Next, scan the embryo in eight to 10 steps to acquire a high-quality image. Presented here are photographs of zebrafish embryos that were taken with a confocal microscope three days after perivitelline injection of MDA-MB-231 cells. MDA-MB-231 cells widely disseminated within the zebrafish body, manifesting highly invasive potential.MCF10A-Ras cells, when implanted to zebrafish embryos, revealed moderate invasive capacity with only a few cells spread to distant parts of the body. Upon transplantation, MCF10A cells remained non-invasive and concentrated within the injection site, confirming that all studied cells reveal different invasive potential. The highly invasive character of MDA-MB-231 cells was reflected in their enhanced migration capacity observed within the perivitelline space.To some extent, such migration was also observed for MCF10A-Ras cells. On the contrary, MCF10A cells did not migrate in the perivitelline space. Distinct metastatic behavior of MDA-MB-231 and MCF10A-Ras cells was also observed when both cell types were implanted into the embryos'duct of Cuvier.As shown, MDA-MB-231 cells migrated independently of one another, while MCF10A-Ras were prone to migrate in clusters. Following this procedure, other measures like immunofluorescence can be performed in order to answer additional questions, such as how cancer cells proliferate in the zebrafish, and how they affect the surrounding host of cells. After watching this video, you will have a good understanding of how to use zebrafish model to study an invasive behavior and assize intravasation and extravasation capacity of human breast cancer cells.

invasive-behavior-of-human-breast-cancer-cells-in-embryonic-zebrafish

Research

JoVE Journal

Cancer Research

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 ...

Ultrasonographic Evaluation of Breast Cancer-related Lymphedema

Lymphedema is one of the most common complications after breast cancer surgery. There are many diagnostic tools for lymphedema, but no standard method yet exists. Progressive Resistance Exercise (PRE) is expected to improve lymphedema without additional swelling. This study showed the therapeutic effects of PRE on lymphedema by using ultrasonography to measure the change in thickness of the muscle and subcutaneous tissue. The thickness of subcutaneous tissue decreased more in the PRE group than in the non-PRE group. Ultrasonography is widely used in many clinics because of its easy accessibility, safety, and inexpensiveness. Ultrasound is one of the best tools for diagnosing and determining treatment efficacy on breast cancer-related lymphedema (BCRL).

This study utilized ultrasonography for diagnosis and follow-up tests to confirm treatment efficacy of Progressive Resistance Exercise (PRE) in breast cancer-related lymphedema (BCRL). Ultrasonography can be applied effectively to ensure diagnosis and treatment of lymphedema.

Lymphedema is one of the most common complications after breast cancer surgery. There are many diagnostic tools for lymphedema, but no standard method yet ...

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 ...

Longitudinal Intravital Imaging of Brain Tumor Cell Behavior in Response to an Invasive Surgical Biopsy

Biopsies are standard of care for cancer treatment and are clinically beneficial as they allow solid tumor diagnosis, prognosis, and personalized treatment determination. However, perturbation of the tumor architecture by biopsy and other invasive procedures has been associated with undesired effects on tumor progression, which need to be studied in depth to further improve the clinical benefit of these procedures. Conventional static approaches, which only provide a snapshot of the tumor, are limited in their ability to reveal the impact of biopsy on tumor cell behavior such as migration, a process closely related to tumor malignancy. In particular, tumor cell migration is the key in highly aggressive brain tumors, where local tumor dissemination makes total tumor resection virtually impossible. The development of multiphoton imaging and chronic imaging windows allows scientists to study this dynamic process in living animals over time. Here, we describe a method for the high-resolution longitudinal imaging of brain tumor cells before and after a biopsy in the same living animal. This approach makes it possible to study the impact of this procedure on tumor cell behavior (migration, invasion, and proliferation). Furthermore, we discuss the advantages and limitations of this technique, as well as the ability of this methodology to study changes in the cancer cell behavior for other surgical interventions, including tumor resection or the implantation of chemotherapy wafers.

Here we describe a method for high-resolution time-lapse multiphoton imaging of brain tumor cells before and after invasive surgical intervention (e.g., biopsy) within the same living animal. This method allows studying the impact of these invasive surgical procedures on tumor cells&#39; migratory, invasive, and proliferative behavior at a single cell level.

Biopsies are standard of care for cancer treatment and are clinically beneficial as they allow solid tumor diagnosis, prognosis, and personalized ...

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 ...

In Vivo Targeting of Xenografted Human Cancer Cells with Functionalized Fluorescent Silica Nanoparticles in Zebrafish

Developing nanoparticles capable of detecting, targeting, and destroying cancer cells is of great interest in the field of nanomedicine. In vivo animal models are required for bridging the nanotechnology to its biomedical application. The mouse represents the traditional animal model for preclinical testing; however, mice are relatively expensive to keep and have long experimental cycles due to the limited progeny from each mother. The zebrafish has emerged as a powerful model system for developmental and biomedical research, including cancer research. In particular, due to its optical transparency and rapid development, zebrafish embryos are well suited for real-time in vivo monitoring of the behavior of cancer cells and their interactions with their microenvironment. This method was developed to sequentially introduce human cancer cells and functionalized nanoparticles in transparent Casper zebrafish embryos and monitor in vivo recognition and targeting of the cancer cells by nanoparticles in real time. This optimized protocol shows that fluorescently labeled nanoparticles, which are functionalized with folate groups, can specifically recognize and target metastatic human cervical epithelial cancer cells labeled with a different fluorochrome. The recognition and targeting process can occur as early as 30 min postinjection of the nanoparticles tested. The whole experiment only requires the breeding of a few pairs of adult fish and takes less than 4 days to complete. Moreover, zebrafish embryos lack a functional adaptive immune system, allowing the engraftment of a wide range of human cancer cells. Hence, the utility of the protocol described here enables the testing of nanoparticles on various types of human cancer cells, facilitating the selection of optimal nanoparticles in each specific cancer context for future testing in mammals and the clinic.

Described here is a method for utilizing zebrafish embryos to study the ability of functionalized nanoparticles to target human cancer cells in vivo. This method allows for the evaluation and selection of optimal nanoparticles for future testing in large animals and in clinical trials.

Developing nanoparticles capable of detecting, targeting, and destroying cancer cells is of great interest in the field of nanomedicine. In vivo animal ...

In Vitro Evaluation of Oncogenic Transformation in Human Mammary Epithelial Cells

Tumorigenesis is a multi-step process in which cells acquire capabilities&#160;that allow their growth, survival, and dissemination under hostile conditions. Different tests seek to identify and quantify these hallmarks of cancerous cells; however, they often focus on a single aspect of cellular transformation and, in fact, multiple tests are required for their proper characterization. The purpose of this work is to provide researchers with a set of tools to assess cellular transformation in vitro from a broad perspective, thereby making it possible to draw sound conclusions.
A sustained proliferative signaling activation is the major feature of tumoral tissues and can be easily monitored under in vitro conditions by calculating the number of population doublings achieved over time. Besides, the growth of cells in 3D cultures allows their interaction with surrounding cells, resembling what occurs in vivo. This enables the evaluation of cellular aggregation and, together with immunofluorescent labeling of distinctive cellular markers, to obtain information on another relevant feature of tumoral transformation: the loss of proper organization. Another remarkable characteristic of transformed cells is their capacity to grow without attachment to other cells and to the extracellular matrix, which can be evaluated with the anchorage assay.
Detailed experimental procedures to evaluate cell growth rate, to perform immunofluorescent labeling of cell lineage markers in 3D cultures, and to test anchorage-independent cell growth in soft agar are provided. These methodologies are optimized for Breast Primary Epithelial Cells (BPEC) due to its relevance in breast cancer; however, procedures can be applied to other cell types after some adjustments.

This protocol provides experimental in vitro tools to evaluate the transformation of human mammary cells. Detailed steps to follow-up cell proliferation rate, anchorage-independent growth capacity, and distribution of cell lineages in 3D cultures with basement membrane matrix are described.

Tumorigenesis is a multi-step process in which cells acquire capabilities&#160;that allow their growth, survival, and dissemination under hostile ...

Isolation and Functional Assessment of Human Breast Cancer Stem Cells from Cell and Tissue Samples

Breast cancer stem cells (BCSCs) are cancer cells with inherited or acquired stem cell-like characteristics. Despite their low frequency, they are major contributors to breast cancer initiation, relapse, metastasis and therapy resistance. It is imperative to understand the biology of breast cancer stem cells in order to identify novel therapeutic targets to treat breast cancer. Breast cancer stem cells are isolated and characterized based on expression of unique cell surface markers such as CD44, CD24 and enzymatic activity of aldehyde dehydrogenase (ALDH). These ALDHhighCD44+CD24- cells constitute the BCSC population and can be isolated by fluorescence-activated cell sorting (FACS) for downstream functional studies. Depending on the scientific question, different in vitro and in vivo methods can be used to assess the functional characteristics of BCSCs. Here, we provide a detailed experimental protocol for isolation of human BCSCs from both heterogenous populations of breast cancer cells as well as primary tumor tissue obtained from breast cancer patients. In addition, we highlight downstream in vitro and in vivo functional assays including colony forming assays, mammosphere assays, 3D culture models and tumor xenograft assays that can be used to assess BCSC function.

This experimental protocol describes the isolation of BCSCs from breast cancer cell and tissue samples as well as the in vitro and in vivo assays that can be used to assess BCSC phenotype and function.

Breast cancer stem cells (BCSCs) are cancer cells with inherited or acquired stem cell-like characteristics. Despite their low frequency, they are major ...

Modeling Breast Cancer in Human Breast Tissue using a Microphysiological System

Breast cancer (BC) remains a leading cause of death for women. Despite more than $700 million invested in BC research annually, 97% of candidate BC drugs fail clinical trials. Therefore, new models are needed to improve our understanding of the disease. The NIH Microphysiological Systems (MPS) program was developed to improve the clinical translation of basic science discoveries and promising new therapeutic strategies. Here we present a method for generating MPS for breast cancers (BC-MPS). This model adapts a previously described approach of culturing primary human white adipose tissue (WAT) by sandwiching WAT between adipose-derived stem cell sheets (ASC)s. Novel aspects of our BC-MPS include seeding BC cells into non-diseased human breast tissue (HBT) containing native extracellular matrix, mature adipocytes, resident fibroblasts, and immune cells; and sandwiching the BC-HBT admixture between HBT-derived ASC sheets. The resulting BC-MPS is stable in culture ex vivo for at least 14 days. This model system contains multiple elements of the microenvironment that influence BC including adipocytes, stromal cells, immune cells, and the extracellular matrix. Thus BC-MPS can be used to study the interactions between BC and its microenvironment. 
We demonstrate the advantages of our BC-MPS by studying two BC behaviors known to influence cancer progression and metastasis: 1) BC motility and 2) BC-HBT metabolic crosstalk. While BC motility has previously been demonstrated using intravital imaging, BC-MPS allows for high-resolution time-lapse imaging using fluorescence microscopy over several days. Furthermore, while metabolic crosstalk was previously demonstrated using BC cells and murine pre-adipocytes differentiated into immature adipocytes, our BC-MPS model is the first system to demonstrate this crosstalk between primary human mammary adipocytes and BC cells in vitro.

This protocol describes the construction of an in vitro microphysiological system for studying breast cancer using primary human breast tissue with off the shelf materials.

Breast cancer (BC) remains a leading cause of death for women. Despite more than $700 million invested in BC research annually, 97% of candidate BC drugs ...

Modeling Brain Metastasis Via Tail-Vein Injection of Inflammatory Breast Cancer Cells

Metastatic spread to the brain is a common and devastating manifestation of many types of cancer. In the United States alone, about 200,000 patients are diagnosed with brain metastases each year. Significant progress has been made in improving survival outcomes for patients with primary breast cancer and systemic malignancies; however, the dismal prognosis for patients with clinical brain metastases highlights the urgent need to develop novel therapeutic agents and strategies against this deadly disease. The lack of suitable experimental models has been one of the major hurdles impeding advancement of our understanding of brain metastasis biology and treatment. Herein, we describe a xenograft mouse model of brain metastasis generated via tail-vein injection of an endogenously HER2-amplified cell line derived from inflammatory breast cancer (IBC), a rare and aggressive form of breast cancer. Cells were labeled with firefly luciferase and green fluorescence protein to monitor brain metastasis, and quantified metastatic burden by bioluminescence imaging, fluorescent stereomicroscopy, and histologic evaluation. Mice robustly and consistently develop brain metastases, allowing investigation of key mediators in the metastatic process and the development of preclinical testing of new treatment strategies.

We describe a xenograft mouse model of breast cancer brain metastasis generated via tail-vein injection of an endogenously HER2-amplified inflammatory breast cancer cell line.

Metastatic spread to the brain is a common and devastating manifestation of many types of cancer. In the United States alone, about 200,000 patients are ...