MB wird durch Zuschüsse aus einem MRC-Stipendium unterstützt. KP und AHM werden durch Zuschüsse von Wessex Medical Research and Cancer Research UK / RCS (England) (C28503/A10013) unterstützt. Wir sind dankbar für die Unterstützung der Universität von Southampton Histochemistry Research Unit.

1. Gründung der Primär Fibroblasten-Kulturen von Darm Explantate <ol><li> Erhalten Proben von normalem menschlichen Darmschleimhaut Gewebe direkt von der chirurgischen Operationssaal und Aussetzung in 7-10 ml PBS, ergänzt mit 100 Einheiten / ml Penicillin, 100 ug / ml Streptomycin und 0,25 &amp;mgr; g / ml Fungizon. </li><li> Im Labor stellen die Probe in der Mitte einer 10-cm-Gewebekulturschale und 3 x waschen mit PBS / Pen-Strep / Fungizone. Nach dem letzten Waschen saugen nicht. </li><li> Mit einer sterilen Pinzette und Skalpell geschnitten das Gewebe in kleine Stücke (ca. 2 mm) und legen jedes Stück in der Mitte des Kreuzes mit dem Skalpell in einer 12-Well-Platte gezogen. Rock the Skalpell vorsichtig über das Gewebe, damit sie halten. </li><li> Kultur die Proben in 750 ul primären Fibroblasten-Wachstumsmedium (DMEM, ergänzt mit 20% fötalem Kälberserum (FCS), 100 U / ml Penicillin, 100 ug / ml Streptomycin und 292 ug / ml L-Glutamin), die subme sollterge das Gewebe ohne Aktivierung es zu schweben. Vermeiden Sie die Platte stören in den nächsten 5 Tagen außer neu Feed alle 2 Tage. </li><li> Im Laufe der nächsten 5 Tage Fibroblasten langsam beginnen, von der Kante des Gewebes herauswachsen. Bei etwa 7 Tage, das mehr sichtbar sein. Nach ca. 3-4 Wochen, und wenn es genügend Fibroblasten wachsen aus, fügen Sie 750 ul Trypsin in jede Vertiefung. Nach Zellen abgelöst, Pool und in ein T-25-Zellkulturflasche (die 5-10 Minuten dauern kann). </li></ol> 2. Organotypische Vorbereitung Vorbereitung der Fibroblasten-Gel imprägniert organotypischen: <ol><li> Vorbereitung einer Fibroblastenzellsuspension mit 5 x 10 5 Zellen pro organotypischen in DMEM mit 10% FCS und 292 ug / ml L-Glutamin ergänzt. </li><li> Bilden die organotypischen Gele auf Eis, in den folgenden Verhältnissen: <ul><li> 7 Volumen Rattenschwanz Collagen: Matrigel-Mischung (1:1) </li><li> 1 Volumen gefiltert 10x DMEM </li><li> 1 Volumen FCS </li><li> 1 Volumen der Fibroblasten-Zellsuspension mit 5 x 10 5 Fibroblasten Für 9 Gele (1 ml pro Gel) 10 ml vorzubereiten und vorsichtig mischen, um Blasen zu vermeiden. </li></ul></li><li> 1 ml in jedes Well einer 24-Well-Platte und Inkubation für 1 Stunde bei 37 ° C in einer feuchten Atmosphäre zu ermöglichen Gele einzustellen. Nach 1 Stunde 1 ml DMEM (10% FCS) / Glut auf der Gele und zurück in den Inkubator über Nacht. </li><li> Am folgenden Tag absaugen Medium von der Oberseite des Gels und der Platte 1 ml Medium, enthaltend 5 × 10 5 CRC Epithelzellen. </li></ol> Herstellung von Gel-beschichteten Nylon Blätter: <ol start="5"><li> Bereiten steril, autoklavierbar Nylon Blätter Messung 1,5 cm x 1,5 cm, im Voraus. </li><li> Mit einer sterilen Pinzette, legen Sie die gewünschte Anzahl der Blätter in einer Nylon 10 cm Kulturschale (in der Regel 4 Nylonblätter können pro Schale untergebracht werden). </li><li> Make-up-Gel auf Eis in der folgenden Reihenfolge (250 ul GesamtNylon pro Blatt Volumen erforderlich): <ul><li> 7 Volumen Rattenschwanz Collagen </li><li> 1 Volumen gefiltert 10x DMEM </li><li> 1 Volumen FCS </li><li> 1 Volumen DMEM 10% FCS / Glut </li></ul></li><li> Wenn die Lösung gelb, zu neutralisieren, indem 0,1 M NaOH in 50 &amp;mgr; l Aliquots, bis die Lösung rosa. </li><li> Add 250 ul dieser Lösung zu jeder Nylonfolie und bei 37 ° C in einer befeuchteten Atmosphäre von 5% CO 2 für 30 min, damit Gel einzustellen. </li><li> Make-up 1% Glutaraldehyd-Lösung in PBS. 10 ml zu je 10 cm Kulturschale einmal das Gel gesetzt und Inkubation bei 4 ° C für 1 Stunde. </li><li> Wasch Nylon Blätter 3x in PBS und 1 x in DMEM (10% FCS) / Glu beimpft und über Nacht in DMEM / Glu bei 4 ° C. </li></ol> Raising organotypischen Gele auf Stahlgitter für die Invasion: <ol start="12"><li> Pre-Vorbereitung Gerüstnetze durch Falten Edelstahlbleche in einem Stativ Bildung. Autoklavieren vor der Verwendung.</li><li> Verwenden einer Pinzette in Ethanol sterilisiert, um eine Stahl-Gitter in jede Vertiefung einer sechs Well-Platte zu platzieren. </li><li> Legen Sie ein Gel-beschichteten Nylon-Blatt mit der Kollagen-Seite nach oben, auf jedes Netz. </li><li> Organotypischen die Gele vorsichtig übertragen von der 24-Well-Platte in die erhöhte Nylon Blatt mit einem Spatel in Ethanol sterilisiert. </li><li> Füllen Sie die gut mit DMEM 10% FCS / Glut mit 10% FCS, bis die Nylonfolie in Kontakt mit dem Medium, aber nicht unter Wasser. Stellen Sie sicher, dass das Medium nicht die organ Gel berühren. </li><li> Inkubation für 14 Tage bei 37 ° C in einer befeuchteten Atmosphäre von 5% CO 2 ersetzt Medien alle 2 Tage. </li></ol> 3. Organotypische Fixation <ol><li> Entfernen ganzen organotypischen einschließlich Nylon Blatt von gut und setzen auf Frischhaltefolie. </li><li> Halbierung organotypischen und Nylon-Blatt mit einem sauberen Einmalskalpell und fixieren beide Hälften in Formaldehyd für 24 Stunden bei Raumtemperatur. </li><li> Formaldehyd Ersetzen mit 70% ethanol nach 24 Stunden und lassen Sie über Nacht vor der Einbettung in Paraffin, Schneiden und Färben. </li></ol> 4. Laser Mikrodissektion des Invasive Margin <ol><li> Abschnitt bis 10 um-Dicke auf Membran Dias. </li><li> Entparaffinieren Abschnitte durch die Anwendung Xylol für 1 min, dann entfernen Xylol und fixieren in 75% Ethanol für eine weitere 1 min. </li><li> Entfernen Ethanol und Fleck mit 0,125% Kresylviolett Lösung für 1 min. Kresylviolett hebt Epithelzellen und erlaubt die einfache Unterscheidung von Stroma. </li><li> Entfernen Kresylviolett und gelten 100% Ethanol für eine weitere 1 min vor dem Spülen mit 100% Ethanol. Lassen Sie Folien an der Luft trocknen für 30 min. </li><li> Führen Lasermikrodissektion mit gewählten Plattform (zB Leica AS-System). </li><li> Setzen Sie den Glasobjektträger mit dem gefärbten Abschnitt, um sich auf den Mikroskoptisch mikrodissektiert Gesicht werden. </li><li> Montieren Sie eine 0,5 ml Mikrozentrifugenröhrchen in die Sammelkassette und 50 ulZell-Lyse-Puffer (z. B. DNA, RNA oder Protein-Lyse-Puffer) an der Kappe in die microdissected Gewebe zu sammeln. </li><li> Unter direkter Sicht mit dem Joystick, um Gewebe von Interesse zu identifizieren, und mit Hilfe der Software-Schnittstelle, kommentieren die gefärbte Bio-Ecke, Hervorhebung Zellen bei der Tumorinvasionsfront mikrodissektiert werden. </li><li> Weisen Sie den Laser zu feuern, die beide aus den markierten Bereich schneiden sollte und treiben mikrodissezierten Gewebe in der Kappe des Mikrozentrifugenröhrchen. </li><li> Sobald genügend Material gesammelt worden ist, werfen Sie die Kassette Sammlung, schließen Sie das Mikrozentrifugenröhrchen und Spin sanft, um die Lyse-Puffer auf den Boden der Röhre zu ziehen. </li><li> Zeigen Proben auf Eis, bis Mikrodissektion abgeschlossen ist. Verfahren Proben durch ein geeignetes Verfahren, um den Analyten von Interesse zu extrahieren. </li></ol>

<ol>
	<li>Nystrom, M. L., Thomas, G. J., Stone, M., Mackenzie, I. C., Hart, I. R., Marshall, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+a+quantitative+method+to+analyse+tumour+cell+invasion+in+organotypic+culture.">Development of a quantitative method to analyse tumour cell invasion in organotypic culture.</a> J Pathol. 205 (4), 468-475 (2005).</li><li>Zhang, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=miR-153+supports+colorectal+cancer+progression+via+pleiotropic+effects+that+enhance+invasion+and+chemotherapeutic+resistance.">miR-153 supports colorectal cancer progression via pleiotropic effects that enhance invasion and chemotherapeutic resistance.</a> Cancer Res. , (2013).</li><li>Bullock, M. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pleiotropic+actions+of+miR-21+highlight+the+critical+role+of+deregulated+stromal+microRNAs+during+colorectal+cancer+progression.">Pleiotropic actions of miR-21 highlight the critical role of deregulated stromal microRNAs during colorectal cancer progression.</a> Cell Death Dis. 20 (4), (2013).</li><li>Jenei, V., Nystrom, M. L., Thomas, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measuring+invasion+in+an+organotypic+model.">Measuring invasion in an organotypic model.</a> Methods Mol Biol. 769, 223-232 (2011).</li><li>De Wever, O., Demetter, P., Mareel, M., Bracke, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stromal+myofibroblasts+are+drivers+of+invasive+cancer+growth.">Stromal myofibroblasts are drivers of invasive cancer growth.</a> Int J Cancer. 123 (10), 2229-2238 (2008).</li><li>Fries, K. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evidence+of+fibroblast+heterogeneity+and+the+role+of+fibroblast+subpopulations+in+fibrosis.">Evidence of fibroblast heterogeneity and the role of fibroblast subpopulations in fibrosis.</a> Clin Immunol Immunopathol. 72 (3), 283-292 (1994).</li><li>Moutasim, K. 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=Betel-derived+alkaloid+up-regulates+keratinocyte+alphavbeta6+integrin+expression+and+promotes+oral+submucous+fibrosis.">Betel-derived alkaloid up-regulates keratinocyte alphavbeta6 integrin expression and promotes oral submucous fibrosis.</a> J Pathol. 223 (3), 366-377 (2011).</li><li>Winter, J., Jung, S., Keller, S., Gregory, R. I., Diederichs, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Many+roads+to+maturity:+microRNA+biogenesis+pathways+and+their+regulation.">Many roads to maturity: microRNA biogenesis pathways and their regulation.</a> Nat Cell Biol. 11 (3), 228-234 (2009).</li><li>Li, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+miRNA+expression+patterns+using+total+RNA+extracted+from+matched+samples+of+formalin-fixed+paraffin-embedded+(FFPE)+cells+and+snap+frozen+cells.">Comparison of miRNA expression patterns using total RNA extracted from matched samples of formalin-fixed paraffin-embedded (FFPE) cells and snap frozen cells.</a> BMC Biotechnol. 7 (36), (2007).</li><li>Szafranska, A. 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=Accurate+molecular+characterization+of+formalin-fixed,+paraffin-embedded+tissues+by+microRNA+expression+profiling.">Accurate molecular characterization of formalin-fixed, paraffin-embedded tissues by microRNA expression profiling.</a> J Mol Diagn. 10 (5), 415-423 (2008).</li></ol>

Die Autoren offenbaren keine potenziellen Interessenkonflikte.

Hier beschreiben wir ein Verfahren, um spezifisch zu isolieren und zu charakterisieren, Tumorzellen, die die Fähigkeit, den Krebs Stroma in den frühesten Stadien der metastatische Fortschreiten in einer 3-dimensionalen Co-Kultur-Konstrukt von epithelialen und stromalen Zellen eindringen erworben. Co-Kultur-Modelle der CRC-Epithelzellen mit einem synthetischen Stroma enthält ex vivo menschlichen Kolon-Fibroblasten nebeneinander bestehen wurden verwendet, um CRC-Invasion in 3-Dimen...

Organotypische Co-Kulturen sind Tissue-Engineering-Modelle, die Hilfe bei der Rekonstruktion der in vivo Tumor-Mikroumgebung in drei Dimensionen durch Nebeneinander malignen Epithelzellen und Stromazellen in einem Kollagen-Gel, die wesentliche Komponenten der extrazellulären Matrix 3.1. Hauptsächlich als ein Verfahren zur Messung der Tumorinvasion konzipiert, organotypics die Abhängigkeit von in vivo-Tiermodellen, und vermeiden die Nachteile der anderen in vitro-Techniken, wie Transwell-Assays, bei dem eindringenden Zellen künstlich in einem monodispersen Zustand 2-4 gedrückt. Die Einbeziehung von Stromazellen in diesen Modellen, wie Fibroblasten, spiegelt die wesentliche Rolle der Tumor-Mikroumgebung bei der Regulierung der Invasion und Metastasierung maligner 3-4, jedoch ist die phänotypische Heterogenität des Stroma ist derart, dass, um die physiologische Relevanz der organotypischen maximieren Modelle, organspezifische, anatomisch genaue ex vivoFibroblasten aufgenommen werden sollten, wo immer möglich 3,6. Organotypics sind eine vielseitige Plattform, um Interaktionen zwischen Tumor-und Stromazellen studieren und werden zunehmend in neue Wege, um die Auswirkungen auf die Tumor-Invasion von chemischen Inhibitoren und gezielten Genveränderungen 7,8 untersuchen eingesetzt. Das Studium der invasiven Tumorrand ist eine besonders aufregende Aussicht. In organotypischen Modellen etabliert Darmkrebs (CRC) Zelllinien in der Regel eine gut geschichtete Epithel, und im Querschnitt, Zellen, die die Fähigkeit, die extrazelluläre Matrix (ECM) eindringen erworben haben, sind leicht erkennbar. Angesichts der etablierten Mikro-topographische Heterogenität von Tumor-und Tumor-assoziierten Stroma-Zellen in vivo, Extrahieren, diese Zellen mit Laser-Mikrodissektion und studiert sie in Isolation, können wichtige biologische Erkenntnisse über die Entstehung von Darmkrebs Metastasen zeigen, und wie kann es effizienter sein richtet. Ichn die folgende Methode, alle Patienten, die Gewebeproben eine schriftliche Einverständniserklärung, und die Studie wurde gespendet von den Institutionen regionaler Forschungsethikkommission genehmigt.

<table border="0" cellpadding="0" cellspacing="0" width="634">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Colorectal cancer cell lines - example shown SW480</td>
			<td style="width:132px;">ATCC</td>
			<td style="width:119px;">ATCC CCL-228</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Collagen</td>
			<td style="width:132px;">BD Biosciences</td>
			<td style="width:119px;">354265</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Matrigel</td>
			<td style="width:132px;">BD Biosciences</td>
			<td style="width:119px;">354234</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Nylon membrane</td>
			<td style="width:132px;">Merck Millipore</td>
			<td style="width:119px;">VVLP01300</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Metal grid</td>
			<td style="width:132px;">The Mesh Company</td>
			<td>WSS20-A4</td>
			<td>themeshcompany.com</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Laser microdissection platform</td>
			<td style="width:132px;">Leica Microsystems</td>
			<td style="width:119px;">Leica AS LMD</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Membrane mounted slides</td>
			<td style="width:132px;">Molecular devices</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Cresyl Violet</td>
			<td style="width:132px;">Merck Millipore</td>
			<td style="width:119px;">1052350025</td>
			<td></td>
		</tr>
	</tbody>
</table>

molecular profiling of the invasive tumor microenvironment in a 3-dimensional model of colorectal cancer cells and ex vivo fibroblasts

Invasion Darmkrebs (CRC)-Zellen haben die Fähigkeit, aus ihrer Schwesterzellen zu befreien, das Stroma zu infiltrieren, und renovieren die extrazelluläre Matrix (ECM) erworben. Charakterisierung der Biologie dieser phänotypisch bestimmte Gruppe von Zellen könnte wesentlich unser Verständnis der frühen Ereignisse verbessern während der metastatischen Kaskade. Tumorinvasion ist ein dynamischer Prozess, durch bidirektionale Interaktion zwischen dem Epithel und malignem Krebs Stroma erleichtert. Um Zell-spezifische Antworten auf den Tumor-Stroma-Schnittstelle haben wir organotypischen Kokultur und Laser Mikrodissektion Techniken kombiniert untersuchen. Organotypische Modelle, in denen wichtige Bestandteile wie Stroma-Fibroblasten sind 3-dimentioanally co-kultiviert mit Krebs Epithelzellen, sind sehr manipulierbar experimentelle Werkzeuge, die Invasion und Krebs-Stroma-Interaktionen ermöglichen, in der Nähe von-ph studiert werdenysiological Bedingungen. Laser Mikrodissektion (LMD) ist eine Technik, die die chirurgische Präparation und Extraktion der verschiedenen Schichten im Tumorgewebe, mit Mikrometer-Präzision Niveau bringt. Durch die Kombination dieser Techniken mit genomischer, Transkriptom und epigenetische Profiling wollen wir zu einem tieferen Verständnis der molekularen Eigenschaften der Invasion von Tumorzellen und die umliegenden Stroma-Gewebe zu entwickeln, und dabei möglicherweise offenbaren neue Biomarker und Chancen für die Entwicklung von Medikamenten in CRC.

Wir haben das obige Verfahren, um mehrere Kombinationen von CRC-Zelllinien und Stromazellen aufgebracht. Ein Beispiel hier präsentiert wird, ist SW480 CRC epithelialen Zelllinien mit primären humanen ex vivo Darm Fibroblasten. 3-dimensionale Co-Kulturen sind zum Vergleich der unterschiedlich exprimierten miRNAs zwischen Zellen an der invasiven Tumorfront ausgebildet (Fig. 1), um Mikroskopie und Laser-Capture-Mikrodissektion (Fig. 2) unterzogen und durch microRNA (miRNA) Profi...

Watch this Scientific Journal Video about Molecular Profiling of the Invasive Tumor Microenvironment in a 3-Dimensional Model of Colorectal Cancer Cells and Ex vivo Fibroblasts at JoVE.com

Molecular Profiling of the Invasive Tumor Microenvironment in a 3-Dimensional Model of Colorectal Cancer Cells and Ex vivo Fibroblasts

Molecular Profiling von Laser mikrodissektiert Zellen und Stroma aus synthetischen, Tissue-Engineering-Darmkrebs-Modelle stellt einen neuartigen Ansatz zur manipulierbaren und an der Schnittstelle zwischen Tumorzellen zu charakterisieren und zu sezieren die unverwechselbare Biologie an der invasiven Front und Krebs Stromazellen.

Molecular Profiling von der invasiven Tumor-Microenvironment in einem 3-Dimensional Model of Colorectal Cancer Cells und<em&gt; Ex-vivo-</em&gt; Fibroblasten

Invading colorectal cancer (CRC) cells have acquired the capacity to break free from their sister cells, infiltrate the stroma, and remodel the ...

molecular-profiling-invasive-tumor-microenvironment-3-dimensional

Research

JoVE Journal

Medicine

Molecular Profiling of the Invasive Tumor Microenvironment in a 3-Dimensional Model of Colorectal Cancer Cells and Ex vivo Fibroblasts

11.0K Aufrufe.  University of Southampton School of Medicine.  Molecular Profiling von Laser mikrodissektiert Zellen und Stroma aus synthetischen, Tissue-Engineering-Darmkrebs-Modelle stellt einen neuartigen Ansatz zur manipulierbaren und an der Schnittstelle zwischen Tumorzellen zu charakterisieren und zu sezieren die unverwechselbare Biologie an der invasiven Front und Krebs Stromazellen. 

Serie: Molecular Profiling of the Invasive Tumor Microenvironment in a 3-Dimensional Model of Colorectal Cancer Cells and Ex vivo Fibroblasts

In vivo Bioluminescence Imaging of Tumor Hypoxia Dynamics of Breast Cancer Brain Metastasis in a Mouse Model

It is well recognized that tumor hypoxia plays an important role in promoting malignant progression and affecting therapeutic response negatively. There is little knowledge about in situ, in vivo, tumor hypoxia during intracranial development of malignant brain tumors because of lack of efficient means to monitor it in these deep-seated orthotopic tumors. Bioluminescence imaging (BLI), based on the detection of light emitted by living cells expressing a luciferase gene, has been rapidly adopted for cancer research, in particular, to evaluate tumor growth or tumor size changes in response to treatment in preclinical animal studies. Moreover, by expressing a reporter gene under the control of a promoter sequence, the specific gene expression can be monitored non-invasively by BLI. Under hypoxic stress, signaling responses are mediated mainly via the hypoxia inducible factor-1&alpha; (HIF-1&alpha;) to drive transcription of various genes. Therefore, we have used a HIF-1&alpha; reporter construct, 5HRE-ODD-luc, stably transfected into human breast cancer MDA-MB231 cells (MDA-MB231/5HRE-ODD-luc). In vitro HIF-1&alpha; bioluminescence assay is performed by incubating the transfected cells in a hypoxic chamber (0.1% O2) for 24 hr before BLI, while the cells in normoxia (21% O2) serve as a control. Significantly higher photon flux observed for the cells under hypoxia suggests an increased HIF-1&alpha; binding to its promoter (HRE elements), as compared to those in normoxia. Cells are injected directly into the mouse brain to establish a breast cancer brain metastasis model. In vivo bioluminescence imaging of tumor hypoxia dynamics is initiated 2 wks after implantation and repeated once a week. BLI reveals increasing light signals from the brain as the tumor progresses, indicating increased intracranial tumor hypoxia. Histological and immunohistochemical studies are used to confirm the in vivo imaging results. Here, we will introduce approaches of in vitro HIF-1&alpha; bioluminescence assay, surgical establishment of a breast cancer brain metastasis in a nude mouse and application of in vivo bioluminescence imaging to monitor intracranial tumor hypoxia.

In vivo Bioluminescence Imaging of Tumor Hypoxia Dynamics of Breast Cancer Brain Metastasis in a Mouse Model

Bioluminescence imaging of hypoxia inducible factor-1&alpha; activity is applied to monitor intracranial tumor hypoxia development in a breast cancer brain metastasis mouse model.

In-vivo-Biolumineszenz-Bildgebung von Tumorhypoxie Dynamics of Breast Cancer Hirnmetastasen in einem Mausmodell

It is well recognized that tumor hypoxia plays an important role in promoting malignant progression and affecting therapeutic response negatively. There ...

Forschung

Medizin

Modeling and Imaging 3-Dimensional Collective Cell Invasion

A defining characteristic of cancer malignancy is invasion and metastasis 1. In some cancers (e.g. glioma 2), local invasion into surrounding healthy tissue is the root cause of disease and death. For other cancers (e.g. breast, lung, etc.), it is the process of metastasis, in which tumor cells move from a primary tumor mass, colonize distal sites and ultimately contribute to organ failure, that eventually leads to morbidity and mortality 3. It has been estimated that invasion and metastasis are responsible for 90&#37; of cancer deaths 4. As a result, there has been intense interest in identifying the molecular processes and critical protein mediators of invasion and metastasis for the purposes of improving diagnosis and treatment 5.
A challenge for cancer scientists is to develop invasion assays that sufficiently resemble the in vivo situation to enable accurate disease modeling 6. Two-dimensional cell motility assays are only informative about one aspect of invasion and do not take into account extracellular matrix (ECM) protein remodeling which is also a critical element. Recently, research has refined our understanding of tumor cell invasion and revealed that individual cells may move by elongated or rounded modes 7. In addition, there has been greater appreciation of the contribution of collective invasion, in which cells invade in strands, sheets and clusters, particularly in highly differentiated tumors that maintain epithelial characteristics, to the spread of cancer 8.
We present a refined method 9 for examining the contributions of candidate proteins to collective invasion 10. In particular, by engineering separate pools of cells to express different fluorescent proteins, it is possible to molecularly dissect the activities and proteins required in leading cells versus those required in following cells. The use of RNAi provides the molecular tool to experimentally disassemble the processes involved in individual cell invasion as well as in different positions of collective invasion. In this procedure, mixtures of fluorescently-labeled cells are plated on the bottom of a Transwell insert previously filled with Matrigel ECM protein, then allowed to invade "upwards" through the filter and into the Matrigel. Reconstruction of z-series image stacks, obtained by confocal imaging, into three-dimensional representations allows for visualization of collectively invading strands and analysis of the representation of fluorescently-labeled cells in leading versus following positions.

Models of tumor cell invasion into three-dimensional extracellular matrix better reflect the in vivo situation than two-dimensional motility assays. Using matrix invasion assays combined with confocal imaging of fluorescently-labeled cells, detailed information on invasion modes and the distinct contributions of leading versus following cells can be obtained.

Modeling and Imaging 3-Dimensional Collective Zellinvasion

A defining characteristic of cancer malignancy is invasion and metastasis 1. In some cancers (e.g. glioma 2), local invasion into surrounding healthy ...

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.

Screening für Melanom Modifiers mit einem Zebrafisch Autochthone Tumormodell

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 ...

Live Imaging of Drug Responses in the Tumor Microenvironment in Mouse Models of Breast Cancer

The tumor microenvironment plays a pivotal role in tumor initiation, progression, metastasis, and the response to anti-cancer therapies. Three-dimensional co-culture systems are frequently used to explicate tumor-stroma interactions, including their role in drug responses. However, many of the interactions that occur in vivo in the intact microenvironment cannot be completely replicated in these in vitro settings. Thus, direct visualization of these processes in real-time has become an important tool in understanding tumor responses to therapies and identifying the interactions between cancer cells and the stroma that can influence these responses. Here we provide a method for using spinning disk confocal microscopy of live, anesthetized mice to directly observe drug distribution, cancer cell responses and changes in tumor-stroma interactions following administration of systemic therapy in breast cancer models. We describe procedures for labeling different tumor components, treatment of animals for observing therapeutic responses, and the surgical procedure for exposing tumor tissues for imaging up to 40 hours. The results obtained from this protocol are time-lapse movies, in which such processes as drug infiltration, cancer cell death and stromal cell migration can be evaluated using image analysis software.

We describe a method for imaging response to anti-cancer treatment in vivo and at single cell resolution.

Live-Imaging of Drug Responses in der Tumor-Mikroumgebung in Mausmodellen von Brustkrebs

The tumor microenvironment plays a pivotal role in tumor initiation, progression, metastasis, and the response to anti-cancer therapies. Three-dimensional ...

Initiation of Metastatic Breast Carcinoma by Targeting of the Ductal Epithelium with Adenovirus-Cre: A Novel Transgenic Mouse Model of Breast Cancer

Breast cancer is a heterogeneous disease involving complex cellular interactions between the developing tumor and immune system, eventually resulting in exponential tumor growth and metastasis to distal tissues and the collapse of anti-tumor immunity. Many useful animal models exist to study breast cancer, but none completely recapitulate the disease progression that occurs in humans. In order to gain a better understanding of the cellular interactions that result in the formation of latent metastasis and decreased survival, we have generated an inducible transgenic mouse model of YFP-expressing ductal carcinoma that develops after sexual maturity in immune-competent mice and is driven by consistent, endocrine-independent oncogene expression. Activation of YFP, ablation of p53, and expression of an oncogenic form of K-ras was achieved by the delivery of an adenovirus expressing Cre-recombinase into the mammary duct of sexually mature, virgin female mice. Tumors begin to appear 6 weeks after the initiation of oncogenic events. After tumors become apparent, they progress slowly for approximately two weeks before they begin to grow exponentially. After 7-8 weeks post-adenovirus injection, vasculature is observed connecting the tumor mass to distal lymph nodes, with eventual lymphovascular invasion of YFP+ tumor cells to the distal axillary lymph nodes. Infiltrating leukocyte populations are similar to those found in human breast carcinomas, including the presence of &#945;&#946; and &#947;&#948; T cells, macrophages and MDSCs. This unique model will facilitate the study of cellular and immunological mechanisms involved in latent metastasis and dormancy in addition to being useful for designing novel immunotherapeutic interventions to treat invasive breast cancer.

Activation of latent mutations with adenovirus-Cre into the mammary ductal system results in a clinically relevant metastatic breast cancer. Incorporation of a YFP promoter allows tracking of distal metastatic tumor cells. This model is useful to study latent metastasis, anti-tumor immunity, and for designing novel immunotherapies to treat breast cancer.

Initiation Metastasierende Mammakarzinom durch Targeting des duktalen Epithel mit Adenovirus-Cre: Eine neue transgene Maus-Modell der Brustkrebs

Breast cancer is a heterogeneous disease involving complex cellular interactions between the developing tumor and immune system, eventually resulting in ...

An Ex vivo Model to Study Hormone Action in the Human Breast

The study of hormone action in the human breast has been hampered by lack of adequate model systems. Upon in vitro culture, primary mammary epithelial cells tend to lose hormone receptor expression. Widely used hormone receptor positive breast cancer cell lines are of limited relevance to the in vivo situation. Here, we describe an ex vivo model to study hormone action in the human breast. Fresh human breast tissue specimens from surgical discard material such as reduction mammoplasties or mammectomies are mechanically and enzymatically digested to obtain tissue fragments containing ducts and lobules and multiple stromal cell types. These tissue microstructures kept in basal medium without growth factors preserve their intercellular contacts, the tissue architecture, and remain hormone responsive for several days. They are readily processed for RNA and protein extraction, histological analysis or stored in freezing medium. Fluorescence activated cell sorting (FACS) can be used to enrich for specific cell populations. This protocol provides a straightforward, standard approach for translational studies with highly complex, varied human specimens.

An Ex vivo Model to Study Hormone Action in the Human Breast

We have developed a novel ex vivo model to study hormone action in the human breast. It is based on tissue microstructures isolated from surgical breast tissue specimens which preserve tissue architecture, intercellular interactions, and paracrine signaling.

Ein<em&gt; Ex-vivo-</em&gt; Modell um die Hormonwirkung in der menschlichen Brust Studieren

The study of hormone action in the human breast has been hampered by lack of adequate model systems. Upon in vitro culture, primary mammary epithelial ...

Three-Dimensional (3D) Tumor Spheroid Invasion Assay

Invasion of surrounding normal tissues is generally considered to be a key hallmark of malignant (as opposed to benign) tumors. For some cancers in particular (e.g., brain tumors such as glioblastoma multiforme and squamous cell carcinoma of the head and neck &#8211; SCCHN) it is a cause of severe morbidity and can be life-threatening even in the absence of distant metastases. In addition, cancers which have relapsed following treatment unfortunately often present with a more aggressive phenotype. Therefore, there is an opportunity to target the process of invasion to provide novel therapies that could be complementary to standard anti-proliferative agents. Until now, this strategy has been hampered by the lack of robust, reproducible assays suitable for a detailed analysis of invasion and for drug screening. Here we provide a simple micro-plate method (based on uniform, self-assembling 3D tumor spheroids) which has great potential for such studies. We exemplify the assay platform using a human glioblastoma cell line and also an SCCHN model where the development of resistance against targeted epidermal growth factor receptor (EGFR) inhibitors is associated with enhanced matrix-invasive potential. We also provide two alternative methods of semi-automated quantification: one using an imaging cytometer and a second which simply requires standard microscopy and image capture with digital image analysis.

Three-Dimensional 3D Tumor Spheroid Invasion Assay

Invasion of surrounding normal tissues is a defining characteristic of malignant tumors. We provide here a simple, semi-automated micro-plate assay of invasion into a natural 3D biomatrix that has been exemplified with a number of models of advanced human cancers.

Dreidimensionale (3D) Tumor Spheroid Invasionsassay

Invasion of surrounding normal tissues is generally considered to be a key hallmark of malignant (as opposed to benign) tumors. For some cancers in ...

Studying Pancreatic Cancer Stem Cell Characteristics for Developing New Treatment Strategies

Pancreatic ductal adenocarcinoma (PDAC) contains a subset of exclusively tumorigenic cancer stem cells (CSCs) which have been shown to drive tumor initiation, metastasis and resistance to radio- and chemotherapy. Here we describe a specific methodology for culturing primary human pancreatic CSCs as tumor spheres in anchorage-independent conditions. Cells are grown in serum-free, non-adherent conditions in order to enrich for CSCs while their more differentiated progenies do not survive and proliferate during the initial phase following seeding of single cells. This assay can be used to estimate the percentage of CSCs present in a population of tumor cells. Both size (which can range from 35 to 250 micrometers) and number of tumor spheres formed represents CSC activity harbored in either bulk populations of cultured cancer cells or freshly harvested and digested tumors 1,2. Using this assay, we recently found that metformin selectively ablates pancreatic CSCs; a finding that was subsequently further corroborated by demonstrating diminished expression of pluripotency-associated genes/surface markers and reduced in vivo tumorigenicity of metformin-treated cells. As the final step for preclinical development we treated mice bearing established tumors with metformin and found significantly prolonged survival. Clinical studies testing the use of metformin in patients with PDAC are currently underway (e.g., NCT01210911, NCT01167738, and NCT01488552). Mechanistically, we found that metformin induces a fatal energy crisis in CSCs by enhancing reactive oxygen species (ROS) production and reducing mitochondrial transmembrane potential. In contrast, non-CSCs were not eliminated by metformin treatment, but rather underwent reversible cell cycle arrest. Therefore, our study serves as a successful example for the potential of in vitro sphere formation as a screening tool to identify compounds that potentially target CSCs, but this technique will require further in vitro and in vivo validation to eliminate false discoveries.

Pancreatic cancer stem cells (CSCs) can be expanded in vitro using the anchorage-independent sphere culture technique, which represents a powerful tool to study CSC biology and can serve as the first step to develop novel CSC-targeting therapies. Here the methodology for expanding, analyzing and targeting of pancreatic CSCs is provided.

Studieren Bauchspeicheldrüsenkrebs Stammzelleigenschaften für die Entwicklung neuer Behandlungsstrategien

Pancreatic ductal adenocarcinoma (PDAC) contains a subset of exclusively tumorigenic cancer stem cells (CSCs) which have been shown to drive tumor ...

Isolation and Propagation of Circulating Tumor Cells from a Mouse Cancer Model

Cancer metastasis is the foremost cause of cancer-associated deaths. Recent studies have shown that circulating tumor cells (CTCs) are important in cancer metastasis. Indeed, the number of CTCs correlates with tumor size. Here, a detailed description is provided of a methodology for isolation and propagation of CTCs from a syngeneic mouse model of hepatocellular carcinoma (HCC) which allows for downstream analysis of potentially important molecular mechanisms of solid organ tumor metastasis. This method is efficient and reproducible. It is a non-invasive technique and, therefore, has potential to replace the invasive biopsy of tissues from humans which may be associated with complications. Therefore, the method discussed here allows for the isolation and propagation of CTCs from whole blood samples such that they can be examined and characterized. This has potential for future adaptation for clinical applications such as diagnosis, and personalized targeted therapy.

Circulating tumor cells (CTCs) have been shown to play an important role in tumor metastasis. Here, a method for the isolation and propagation of CTCs from the whole blood of a syngeneic mouse tumor model of hepatocellular carcinoma (HCC) metastasis is described.

Isolierung und Vermehrung von zirkulierenden Tumorzellen aus einer Maus Cancer

Cancer metastasis is the foremost cause of cancer-associated deaths. Recent studies have shown that circulating tumor cells (CTCs) are important in cancer ...

A Brain Tumor/Organotypic Slice Co-culture System for Studying Tumor Microenvironment and Targeted Drug Therapies

Brain tumors are a major cause of cancer-related morbidity and mortality. Developing new therapeutics for these cancers is difficult, as many of these tumors are not easily grown in standard culture conditions. Neurosphere cultures under serum-free conditions and orthotopic xenografts have expanded the range of tumors that can be maintained. However, many types of brain tumors remain difficult to propagate or study. This is particularly true for pediatric brain tumors such as pilocytic astrocytomas and medulloblastomas. This protocol describes a system that allows primary human brain tumors to be grown in culture. This quantitative assay can be used to investigate the effect of microenvironment on tumor growth, and to test new drug therapies. This protocol describes a system where fluorescently labeled brain tumor cells are grown on an organotypic brain slice from a juvenile mouse. The response of tumor cells to drug treatments can be studied in this assay, by analyzing changes in the number of cells on the slice over time. In addition, this system can address the nature of the microenvironment that normally fosters growth of brain tumors. This brain tumor organotypic slice co-culture assay provides a propitious system for testing new drugs on human tumor cells within a brain microenvironment.

Many types of human brain tumors are localized to specific regions within the brain and are difficult to grow in culture. This protocol addresses the role of tumor microenvironment and investigates new drug treatments by analyzing fluorescent primary brain tumor cells growing in an organotypic mouse brain slice. &#160;

Ein Hirntumor / Organotypischen Co-Kultursystem für die Untersuchung Tumor-Microenvironment und gezielte Arzneimitteltherapie

Brain tumors are a major cause of cancer-related morbidity and mortality. Developing new therapeutics for these cancers is difficult, as many of these ...