Name: live imaging to study microtubule dynamic instability in taxane-resistant breast cancers
Uploaded: 2017-02-20T13:00:00.000+00:00
Duration: 6 min 2 s
Description: Watch this Scientific Journal Video about Live Imaging to Study Microtubule Dynamic Instability in Taxane-resistant Breast Cancers at JoVE.com

This research is supported by funding from CBCF (to ZW).

1. Vorbereitung der Zellen für Live-Imaging <ol><li> Zellkultur und Seeding <ol><li> Verwenden MCF-7 Brustkrebszellen , ausgewählt für die Resistenz gegen Docetaxel (MCF-7 TXT) und deren nicht-resistenten parentalen Zelllinie (MCF-7 CC). Die detaillierten Auswahlprozess und die Charakterisierung dieser ausgewählten Zelllinien wurden zuvor 24 beschrieben. </li><li> Wachsen alle Zellen in 10 cm-Kulturschalen bei 37 ° C in einem Medium, 90% Dulbecco besteht modifiziertem Eagle-Medium (DMEM) und 10% fötales Rinderserum (FBS) und supplementiert mit nicht-essentiellen Aminosäuren. Pflegen Sie das Medium in einer 5% igen CO 2 -Atmosphäre. Pflegen MCF-7 TXT Zellen bei 5 nM Docetaxel. </li><li> Seed-Zellen auf Deckgläser für die Live-Darstellung. Sterilisieren 24 mm poly-L-Lysin beschichteten Glasplättchen, indem sie mit 70% -igem Alkohol gespült und dann über Nacht sie UV ausgesetzt wird. Legen Sie die Deckgläser in einer 6-Well-Kulturplatte von 35 mm. Place ein Deckglas in jeder Vertiefung. </li><li> Entfernen Sie das Medium aus dem 10-cm-Kulturschale und waschen Sie die Zellen mit PBS. Mit 0,5 ml Trypsin-EDTA in die Schale um die Zellen von der Schale zu lösen. 5 ml Kulturmedium in die Schale um das Trypsin nach der Ablösung der Zellen zu neutralisieren. </li><li> Zähle die Zellen mit einem Hämozytometer die Anzahl der Zellen pro Volumeneinheit zu ermitteln. </li><li> In etwa 10 5 Zellen in jede Vertiefung auf der Basis der Zellzahl pro Volumeneinheit. sanft, legte die Platte wieder in den Inkubator Nach Schütteln, damit die Zellen an den Deckgläsern zu befestigen. </li></ol></li><li> Expression von GFP-markierten α-Tubulin <ol><li> Zu testen Dynamik der Mikrotubuli, Transduktion der Zellen mit GFP-markierten α-Tubulin mit dem handelsüblichen GFP Transduktion Steuerung (zB BacMam) nach dem Protokoll des Herstellers. </li><li> Kultur der Zellen in der Vertiefung für 36 h in einem 37 ° C Zellkulturinkubator com zu ermöglichenplete Adhäsion und 60% Konfluenz. </li><li> Berechne den geeigneten Volumen GFP-markierten α-Tubulin zu jeder Vertiefung hinzugefügt, entsprechend der folgenden Gleichung: <img alt="Gleichung" src="/files/ftp_upload/55027/55027eq1.jpg" /> Die Anzahl der Zellen ist, die geschätzte Gesamtzahl der Zellen in der Vertiefung zum Zeitpunkt der Markierung und der gewünschten PPC ist die Anzahl der Partikel pro Zelle. HINWEIS: Die MCF-7 - Zellen Seeding sollte die Zellzahl 10 5 bis 2 x 10 5 mit einem gewünschten PPC 20 verdoppelt haben, das Volumen für jede Deck benötigt daher 40 &amp; mgr; l. Für verschiedene Zellen, berechnet das Volumen auf der obigen Formel basiert möglicherweise nicht die beste sein. Das genaue Volumen sollte entsprechend der tatsächlichen Expression von GFP-Tubulin eingestellt werden. </li><li> Mische die GFP-markierten α-Tubulin mehrfach durch Umdrehen um eine homogene Lösung zu gewährleisten. Nicht mit dem Vortex. HINWEIS: Für die Steuerung, die Null (Kontrolle) Reagens fehlt jede Säugetier genetischeElemente und können potentielle Baculovirus-vermittelte Effekte und Hintergrundfluoreszenz verwendet werden, bestimmen zu helfen. Eine nicht gezielt GFP Transduktion Kontrolle kann auch verwendet werden, die die gesamte Zelle leuchtet. </li><li> Ersetzen Sie das Kulturmedium mit frischem Medium. 2 mL des neuen Mediums und 40 ul GFP-markierten α-Tubulin zu jeder Vertiefung. </li><li> Schütteln Sie die Platte vorsichtig vollständige Durchmischung von GFP-markierten α-Tubulin mit dem Kulturmedium zu ermöglichen. Bringen Sie die Platte mit dem Kultur-Inkubator und Inkubation für 24 h, um die Expression von GFP-Tubulin zu ermöglichen. </li></ol></li><li> Treat Zellen mit Docetaxel Hinweis: Dieses Experiment wird die Wirkung von Docetaxel auf Mikrotubuli dynamische Instabilität zu testen. Somit werden die Zellen mit der gewünschten Konzentration von Docetaxel behandelt. <ol><li> Bereiten Sie ein Medium, 90% DMEM und zu 10% der FBS und ergänzt mit nicht-essentiellen Aminosäuren. Verwenden Sie DMEM ohne Phenol rot, weil Phenolrot mit dem fluorescen störence von GFP-Tubulin. Fügen Sie die gewünschte Konzentration von Docetaxel (im Bereich von 10 nm bis 10 &amp; mgr; M). Die Stammlösung von Docetaxel ist 10 mM in Dimethylsulfoxid (DMSO). </li><li> Vorwärmen der Docetaxel enthaltende Medium auf 37 ° C in der Gewebekultur-Inkubator. </li><li> Ersetzen Sie die normalen Kulturmedium mit der Docetaxel-haltigen Medium und Inkubation für 30 min in der Gewebekultur-Inkubator. Es sollte für jeden Docetaxel-Konzentration mindestens 3 Deck pro Vertiefung sein. </li></ol></li></ol> 2. Live-Imaging zu untersuchen Mikrotubuli dynamische Instabilität <ol><li> Einrichten des Systems <ol><li> Führen Experimente in einer Kammer bei 37 ° C und 5% CO 2 gehalten. Erwerben Fluoreszenzbilder von Zeitablauf mit einem mikroskopischen System mit einem 60X versehen, 1,42 NA Öl Objektivlinse auf einem invertierten Fluoreszenzmikroskop und mit einer CCD-Kamera. </li><li> Legen Sie die Zellen für Livebild. Vorwärmen sowohl der Probenhalter unddas Medium auf 37 ° C. Wählen Sie ein Deckglas zu untersuchen. Montieren Sie das Deckglas von Interesse auf einem Probenhalter und Inkubation mit 1 ml der Docetaxel-haltigen Medium hergestellt in Schritt 1.3.1. </li></ol></li><li> Live - Bildgebung von Mikrotubuli dynamische Instabilität <ol><li> Identifizieren Sie die Zellen, die für die Bildgebung verwendet wird. Sie sollten flach sein, haben eine hohe Fluoreszenzintensität ausgedrückt GFP-Tubulin und haben klare Mikrotubuli-Strukturen. </li><li> Wählen einer Zelle aus der Gruppe der identifizierten Zellen aus Schritt 2.2.1 zunächst zu untersuchen. Konzentrieren sich auf den Randbereich der identifizierten Zelle. Stellen Sie das Programm für die Belichtungszeit und die Häufigkeit der Bildaufnahme auf. Als Belichtungszeit gewöhnlich 0,5 s ist, werden die Bilder alle zwei s erfasst werden. </li><li> Lassen Sie eine zusätzliche 20 Minuten für die Schritte von 1,33 bis 2.2.3. Somit genau 50 min nach der Zugabe von Docetaxel, wie in Schritt 1.3.3 beschrieben, beginnen imaging (dies für Normung). </li><li> Notieren Sie sich die Mikrotubuli-dynamics für 2 Minuten, die ein Foto alle 2 s. Insgesamt erwerben 60 Bilder für die identifizierte Zelle. </li><li> Gehen Sie zum nächsten identifizierten Zelle und wiederholen Sie die Schritte 2.2.2 bis 2.2.4. Wiederholen Sie den Vorgang, bis 5 Zellen abgebildet wurden. Es ist zwingend notwendig, dies zu tun, bevor die Zeit 70 min nach der Zugabe von Docetaxel erreicht, wie es in Schritt 1.3.3 beschrieben. </li><li> Für jede Behandlungsbedingung, wiederholen Sie die Schritte 2.2.1 für 3 verschiedene Deck bis 2.2.5. Insgesamt Bild 15 Zellen, die genug Daten Mikrotubuli dynamische Instabilität zu messen. </li></ol></li></ol> 3. Bildverarbeitung und Datenanalyse <ol><li> Deconvolution der Bilder <ol><li> Entfalten die aufgenommenen Bilder eine hohe Qualität zu erreichen. Öffnen Sie das Entfaltungsprogramm mit dem Mikroskopsystem ausgestattet. </li><li> Klicken Sie auf &quot;Bearbeiten&quot; und wählen Sie &quot;entfalten.&quot; Ziehen Sie die Datei in den &quot;Input&quot; Fenster und klicken Sie auf &quot;Do&quot; Die Bilddatei wird entfalteten und dieentfalteten Datei wird automatisch als neue Datei gespeichert werden. </li></ol></li><li> Die Erzeugung von Videos <ol><li> Klicken Sie auf die entfalteten Bilddatei mit ausgestatteter Software zu öffnen. </li><li> Klicken Sie auf &quot;Datei&quot; und wählen Sie &quot;als Film speichern&quot;. Wählen Sie den &quot;Filmformat&quot; als &quot;AV&quot; und &quot;Animation-Stil&quot; als &quot;Forward&quot;. Stellen Sie die &quot;Komprimierungsqualität&quot; auf &quot;100%&quot; und der &quot;Frame Rate&quot; bis &quot;5 / Sekunde.&quot; </li><li> Überprüfen Sie die Schachtel &quot;Animieren durch die Zeit&quot; und klicken Sie auf &quot;Do it.&quot; Das Video wird erzeugt werden. </li></ol></li><li> Die Messung der Mikrotubuli - Verkürzung und Wachstumsrate <ol><li> Identifizieren Sie die Mikrotubuli, die für die Messung verwendet wird. Für jede Zelle wird nur wenige Mikrotubuli Lage sein, ihre Verkürzung oder Wachstum haben klar und vollständig folgt. </li><li> Untersuchen jeden Frame des Videos den Rahmen zu identifizieren, die die Ausgangslänge des Mikrotubuli a zeigtnd der Rahmen mit den meisten verlängert oder verkürzt Mikrotubuli. Messen der Änderung in der Länge zwischen den beiden Mikrotubuli und dem zwischen den beiden Rahmen verstrichene Zeit. </li><li> Berechnen Sie die Geschwindigkeit des Wachstums oder der Verkürzung durch die Längenänderung durch Zeitteilung (die Einheit &amp; mgr; m / s). Für jede Behandlungsbedingung, folgen mindestens 10 Zellen und mindestens 20 Mikrotubuli messen. </li><li> Berechnen Sie den Mittelwert und der Standardfehler für jede Behandlungsbedingung. Analysieren Sie den statistischen Unterschied zwischen den Bedingungen des Student-Test. Melden Sie die Daten in einer Tabelle und / oder in einem Diagramm. </li></ol></li></ol>

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Die Autoren erklären, dass sie keine finanziellen Interessen haben.

Es gibt zwei Hauptmethoden Mikrotubuli dynamische Instabilität zu messen: in vitro und in vivo. In dem in vitro - Verfahren wird gereinigtes Tubulin verwendet Mikrotubuli dynamische Instabilität mit Computer-enhanced Zeitrafferdifferentialinterferenzkontrastmikroskopie zu messen. In dem in vivo - Verfahren, mikroinjiziert Fluoreszenz Tubulin oder Tubulin-GFP exprimiert, in Mikrotubuli eingebaut. Die Dynamik (Wachstum und Verkürzung) der Mikrotubuli wird dann durch Zeitraffer unter ...

<html> Die Haupttodesursache Brustkrebs ist durch Metastase 1, 2. Taxane wie Docetaxel und Paclitaxel, werden derzeit als First-Line - Therapien bei der Behandlung von metastasierendem Brustkrebs 2, 3, 4, 5, 6 verwendet. Sie sind Teil einer Gruppe von Mikrotubuli-Targeting-Mittel (MTAs), die die Dynamik der Mikrotubuli stören. Allerdings ist eine der größten Herausforderungen für die Taxane in kurativen Therapie ist die Entwicklung von Taxan - Resistenz von Krebszellen unter Verwendung, die 7 bis Wiederauftreten der Krankheit führt. Arzneimittelresistenz ist für mehr als 90% aller Todesfälle bei Patienten mit metastasiertem Brustkrebs , 7. Mikrotubuli sind durch die Polymerisation von α- und β-Tubulin-Heterodimeren gebildetclass = &quot;xref&quot;&gt; 8, 9. Die genaue Regelung der Dynamik der Mikrotubuli ist wichtig für viele zelluläre Funktionen, einschließlich der Zellpolarisation, Zellzyklus, den intrazellulären Transport und Zellsignalisierung. Dysregulation von Mikrotubuli und deren Dynamik werden die Zellfunktion stören und führen in den Zelltod 10, 11. Je nachdem , wie sie diese Dysregulation verursachen kann MTA Medikamente entweder als Mikrotubuli stabilisierende Mittel eingestuft werden (dh Taxane) oder Mikrotubuli-destabalizing Mittel (dh, Vinca - Alkaloiden oder Colchicin-Bindungsstelle Mittel) 20. Trotz ihrer gegenläufigen Effekte auf Mikrotubuli Masse, bei einer ausreichenden Dosierung, beide Klassen können 21 Krebszellen durch ihre Auswirkungen auf die Dynamik der Mikrotubuli töten. Taxane funktionieren in erster Linie durch die Mikrotubuli Spindel 12 zu stabilisieren, was zuchromosomale Fehlausrichtung. Die anschließende unaufhörlichen Aktivierung der Spindelanordnung checkpoint (SAC) hemmt die Zelle in die Mitose. Längerer mitotischen Arrest bewirkt dann , dass die Apoptose 13, 14. Taxan interagiert mit Mikrotubuli durch die Taxan - Bindungsstelle auf β-Tubulin - 8, 15, die im zusammengebauten Tubulin 16 nur vorhanden ist. Mehrere Mechanismen für Taxan Widerstand haben 9 vorgeschlagen, 17. Diese Mechanismen umfassen sowohl allgemeine Multidrug - Resistenz durch die Überexpression von arzneimittel Efflux Proteine und Taxan-spezifischen Widerstand 5, 9, 18, 19. Beispielsweise Taxan-resistenten Krebszellen Expression und Funktion bestimmter β-Tub möglicherweise verändertulin Isotypen 5, 9, 19, 20, 21, 22, 23. Durch die Verwendung eines in vivo - Verfahren Mikrotubuli dynamische Instabilität zu messen, zeigen wir , dass, wenn im Vergleich zu nicht-resistenten, elterliche MCF-7 - Zellen CC 17 die Mikrotubuli - Dynamik von Docetaxel-resistenten MCF-7 - Zellen zu TXT Docetaxel Behandlung unempfindlich sind. Zum besseren Verständnis der Funktion von MTAs und der genaue Mechanismus der Taxan-Resistenz in Krebszellen zu verstehen, ist es wichtig, die Dynamik der Mikrotubuli zu messen. Hier berichten wir über eine in vivo - Methode, dies zu tun. Durch die Verwendung von Echtzeit- Bildgebung in Kombination mit der Expression von GFP-markierten Tubulin in Zellen, können wir die Dynamik der Mikrotubuli von MCF-7 TXT und MCF-7 CC - Zellen mit und wi messenthout Behandlung mit Docetaxel. Die Ergebnisse können uns wirksamer Medikamente helfen entwerfen, die Taxan Widerstand überwinden kann.

<table><tbody><tr><td>Dulbecco&#039;s Modified Eagle&#039;s Medium (DMEM)</td><td>Sigma-Aldrich</td><td>D5796</td><td></td></tr><tr><td>Non-essential amino acids</td><td>Life Technologies, Invitrogen</td><td>11140-050</td><td></td></tr><tr><td>FBS</td><td>Gibco, Invitrogen</td><td>12483</td><td></td></tr><tr><td>Anti-Anti (100x)</td><td>Life Technologies, Invitrogen</td><td>15240-062</td><td></td></tr><tr><td>docetaxel</td><td>Sigma-Aldrich</td><td>01885-5mg-F</td><td></td></tr><tr><td>DMEM phenol red-free</td><td>Gibco, Invitrogen</td><td>21063</td><td></td></tr><tr><td>CellLight Reagent *BacMam 2.0* GFP-tubulin</td><td>ThermoFisher Scientific</td><td>C10613</td><td>Key reagent for expressing GFP tubulin in cells</td></tr><tr><td>CellLight Reagent *BacMam 2.0* GFP</td><td>ThermoFisher Scientific</td><td>B10383</td><td>Control</td></tr><tr><td>Dimethyl Sulfoxide (DMSO)</td><td>Sigma-Aldrich+B9:AA9</td><td>472301</td><td>for dissoving decetaxel</td></tr><tr><td>22-mm glass coveslip</td><td>Fisher Scientifics</td><td>12-545-101</td><td></td></tr><tr><td>6-well culture plate</td><td>Greiner Bio-One International</td><td>6 Well Celi Culture Plate</td><td></td></tr><tr><td>DeltaVision Microscopy Imaging Systems</td><td>GE Health</td><td></td><td>This system is equipped with weather station for controlling temperature and CO2. It also equipped with Worx Software for deconvolution and time lapse control.</td></tr><tr><td>Trypsin-EDTA (0.25%), phenol red</td><td>ThermoFisher Scientific</td><td>25200056</td><td></td></tr><tr><td>Bright-Line Hemacytometer Set, Hausser Scientific</td><td>Hausser Scientific, Distributed by VWR</td><td>Supplier No.: 1492 VWR No.:15170-172</td><td></td></tr></tbody></table>

live imaging to study microtubule dynamic instability in taxane-resistant breast cancers

Taxanes such as docetaxel belong to a group of microtubule-targeting agents (MTAs) that are commonly relied upon to treat cancer. However, taxane resistance in cancerous cells drastically reduces the effectiveness of the drugs' long-term usage. Accumulated evidence suggests that the mechanisms underlying taxane resistance include both general mechanisms, such as the development of multidrug resistance due to the overexpression of drug-efflux proteins, and taxane-specific mechanisms, such as those that involve microtubule dynamics. 
Because taxanes target cell microtubules, measuring microtubule dynamic instability is an important step in determining the mechanisms of taxane resistance and provides insight into how to overcome this resistance. In the experiment, an in vivo method was used to measure microtubule dynamic instability. GFP-tagged &#945;-tubulin was expressed and incorporated into microtubules in MCF-7 cells, allowing for the recording of the microtubule dynamics by time lapse using a sensitive camera. The results showed that, as opposed to the non-resistant parental MCF-7CC cells, the microtubule dynamics of docetaxel-resistant MCF-7TXT cells are insensitive to docetaxel treatment, which causes the resistance to docetaxel-induced mitotic arrest and apoptosis. This paper will outline this in vivo method of measuring microtubule dynamic instability.

Mit dem Protokoll hier vorgestellten, untersuchten wir die Wirkung von Docetaxel auf die Mikrotubuli - Dynamik der normalen (MCF-7 CC) und Docetaxel-resistenten (MCF-7 TXT) Brustkrebszellen. Zwei Sätze von Aufnahmen zeigen die Wirkung von Docetaxel (0,5 uM) auf Mikrotubuli Wachstum und Verkürzung in MCF-7 CC und MCF-7 - TXT - Zellen (1A). Wir auch die Geschwindigke...

Watch this Scientific Journal Video about Live Imaging to Study Microtubule Dynamic Instability in Taxane-resistant Breast Cancers at JoVE.com

Live Imaging to Study Microtubule Dynamic Instability in Taxane-resistant Breast Cancers

In this paper, we report a protocol describing an in vivo method to measure microtubule dynamic instability in docetaxel-resistant breast cancer cells (MCF-7TXT). In this method, a deconvolution microscopy imaging system is used to detect the expression of GFP-tubulin in target cells.

Live-Imaging zur Untersuchung Mikrotubuli dynamische Instabilität in Taxan-resistenten Mammakarzinome

Taxanes such as docetaxel belong to a group of microtubule-targeting agents (MTAs) that are commonly relied upon to treat cancer. However, taxane ...

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7.5K Aufrufe.  University of Alberta. In this paper, we report a protocol describing an in vivo method to measure microtubule dynamic instability in docetaxel-resistant breast cancer cells (MCF-7TXT). In this method, a deconvolution microscopy imaging system is used to detect the expression of GFP-tubulin in target cells. 

Serie: Live Imaging to Study Microtubule Dynamic Instability in Taxane-resistant Breast Cancers

Live-imaging of Breast Epithelial Cell Migration After the Transient Depletion of TIP60

The wound-healing assay is efficient and one of the most economical ways to study cell migration in vitro. Conventionally, images are taken at the beginning and end of an experiment using a phase-contrast microscope, and the migration abilities of cells are evaluated by the closure of wounds. However, cell movement is a dynamic phenomenon, and a conventional method does not allow for tracking single-cell movement. To improve current wound-healing assays, we use live-cell imaging techniques to monitor cell migration in real time. This method allows us to determine the cell migration rate based on a cell tracking system and provides a clearer distinction between cell migration and cell proliferation. Here, we demonstrate the use of live-cell imaging in wound-healing assays to study the different migration abilities of breast epithelial cells influenced by the presence of TIP60. As cell motility is highly dynamic, our method provides more insights into the processes of wound healing than a snapshot of wound closure taken with the traditional imaging techniques used for wound-healing assays.

Here, we present the real-time monitoring of cell migration in a wound-healing assay using TIP60-depleted MCF10A breast epithelial cells. The implementation of live-cell imaging techniques in our protocol allows us to analyze and visualize single-cell movement in real time and across time.

Live-Darstellung der Brust Epithelzelle Migration nach der vorübergehenden Erschöpfung der TIP60

The wound-healing assay is efficient and one of the most economical ways to study cell migration in vitro. Conventionally, images are taken at the ...

Forschung

Krebsforschung

Monitoring Tumor Metastases and Osteolytic Lesions with Bioluminescence and Micro CT Imaging

Following intracardiac delivery of MDA-MB-231-luc-D3H2LN cells to Nu/Nu mice, systemic metastases developed in the injected animals. Bioluminescence imaging using IVIS Spectrum was employed to monitor the distribution and development of the tumor cells following the delivery procedure including DLIT reconstruction to measure the tumor signal and its location.
Development of metastatic lesions to the bone tissues triggers osteolytic activity and lesions to tibia and femur were evaluated longitudinally using micro CT. Imaging was performed using a Quantum FX micro CT system with fast imaging and low X-ray dose. The low radiation dose allows multiple imaging sessions to be performed with a cumulative X-ray dosage far below LD50. A mouse imaging shuttle device was used to sequentially image the mice with both IVIS Spectrum and Quantum FX achieving accurate animal positioning in both the bioluminescence and CT images. The optical and CT data sets were co-registered in 3-dimentions using the Living Image 4.1 software. This multi-mode approach allows close monitoring of tumor growth and development simultaneously with osteolytic activity.

An experimental mouse model of bone metastasis was established following intracardiac delivery of luciferase expressing mammary tumor cells. Tumor development and resulted osteolytic lesion were monitored longitudinally with bioluminescence and micro CT imaging.

Überwachung Tumormetastasen und Osteolysen mit Biolumineszenz und Micro-CT Imaging

Following intracardiac delivery of MDA-MB-231-luc-D3H2LN cells to Nu/Nu mice, systemic metastases developed in the injected animals. Bioluminescence ...

Medizin

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 ...

Long-term Live-cell Imaging to Assess Cell Fate in Response to Paclitaxel

Live-cell imaging is a powerful technique that can be used to directly visualize biological phenomena in single cells over extended periods of time. Over the past decade, new and innovative technologies have greatly enhanced the practicality of live-cell imaging. Cells can now be kept in focus and continuously imaged over several days while maintained under 37 &#176;C and 5% CO2 cell culture conditions. Moreover, multiple fields of view representing different experimental conditions can be acquired simultaneously, thus providing high-throughput experimental data. Live-cell imaging provides a significant advantage over fixed-cell imaging by allowing for the direct visualization and temporal quantitation of dynamic cellular events. Live-cell imaging can also identify variation in the behavior of single cells that would otherwise have been missed using population-based assays. Here, we describe live-cell imaging protocols to assess cell fate decisions following treatment with the anti-mitotic drug paclitaxel. We demonstrate methods to visualize whether mitotically arrested cells die directly from mitosis or slip back into interphase. We also describe how the fluorescent ubiquitination-based cell cycle indicator (FUCCI) system can be used to assess the fraction of interphase cells born from mitotic slippage that are capable of re-entering the cell cycle. Finally, we describe a live-cell imaging method to identify nuclear envelope rupture events.

Live-cell imaging provides a wealth of information on single cells or whole populations that is unattainable by fixed cell imaging alone. Here, live-cell imaging protocols to assess cell fate decisions following treatment with the anti-mitotic drug paclitaxel are described.

Langfristige Leben-Cell Imaging zu Zelle Schicksal als Reaktion auf Paclitaxel bewerten

Live-cell imaging is a powerful technique that can be used to directly visualize biological phenomena in single cells over extended periods of time. Over ...

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 ...

Time-lapse Imaging of Primary Preneoplastic Mammary Epithelial Cells Derived from Genetically Engineered Mouse Models of Breast Cancer

Time-lapse imaging can be used to compare behavior of cultured primary preneoplastic mammary epithelial cells derived from different genetically engineered mouse models of breast cancer. For example, time between cell divisions (cell lifetimes), apoptotic cell numbers, evolution of morphological changes, and mechanism of colony formation can be quantified and compared in cells carrying specific genetic lesions. Primary mammary epithelial cell cultures are generated from mammary glands without palpable tumor. Glands are carefully resected with clear separation from adjacent muscle, lymph nodes are removed, and single-cell suspensions of enriched mammary epithelial cells are generated by mincing mammary tissue followed by enzymatic dissociation and filtration. Single-cell suspensions are plated and placed directly under a microscope within an incubator chamber for live-cell imaging. Sixteen 650 &mu;m x 700 &mu;m fields in a 4x4 configuration from each well of a 6-well plate are imaged every 15 min for 5 days. Time-lapse images are examined directly to measure cellular behaviors that can include mechanism and frequency of cell colony formation within the first 24 hr of plating the cells (aggregation versus cell proliferation), incidence of apoptosis, and phasing of morphological changes. Single-cell tracking is used to generate cell fate maps for measurement of individual cell lifetimes and investigation of cell division patterns. Quantitative data are statistically analyzed to assess for significant differences in behavior correlated with specific genetic lesions.

Time-lapse imaging is used to assess behavior of primary preneoplastic mammary epithelial cells derived from genetically engineered mouse models of breast cancer risk to determine if there are correlations between specific behavioral parameters and distinct genetic lesions.

Zeitraffer-Imaging of Primary Präkanzeröse Brustepithelzellen aus gentechnisch veränderten Mausmodellen der Breast Cancer Abgeleitet

Time-lapse  imaging can be used to compare behavior of cultured primary preneoplastic  mammary epithelial cells derived from different genetically ...

Real-time Imaging of Myeloid Cells Dynamics in ApcMin/+ Intestinal Tumors by Spinning Disk Confocal Microscopy

Myeloid cells are the most abundant immune cells within tumors and have been shown to promote tumor progression. Modern intravital imaging techniques enable the observation of live cellular behavior inside the organ but can be challenging in some types of cancer due to organ and tumor accessibility such as intestine. Direct observation of intestinal tumors has not been previously reported. A surgical procedure described here allows direct observation of myeloid cell dynamics within the intestinal tumors in live mice by using transgenic fluorescent reporter mice and injectable tracers or antibodies. For this purpose, a four-color, multi-region, micro-lensed spinning disk confocal microscope that allows long-term continuous imaging with rapid image acquisition has been used. ApcMin/+ mice that develop multiple adenomas in the small intestine are crossed with c-fms-EGFP mice to visualize myeloid cells and with ACTB-ECFP mice to visualize intestinal epithelial cells of the crypts. Procedures for labeling different tumor components, such as blood vessels and neutrophils, and the procedure for positioning the tumor for imaging through the serosal surface are also described. Time-lapse movies compiled from several hours of imaging allow the analysis of myeloid cell behavior in situ in the intestinal microenvironment.

Real-time Imaging of Myeloid Cells Dynamics in ApcMin/+ Intestinal Tumors by Spinning Disk Confocal Microscopy

By using transgenic reporter mice and injectable fluorescent labels, long-term intravital spinning disk confocal microscopy enables direct visualization of myeloid cell behavior into intestinal adenoma in the ApcMin/+ colorectal cancer model.

Echtzeit-Imaging von myeloischen Zellen in Dynamics<em&gt; Apc<sup&gt; Min / +</sup</em&gt; Darmtumoren durch Spinning-Disk-konfokale Mikroskopie

Myeloid cells are the most abundant immune cells within tumors and have been shown to promote tumor progression. Modern intravital imaging techniques ...

Immunologie und Infektion

Simultaneous Visualization of the Dynamics of Crosslinked and Single Microtubules In Vitro by TIRF Microscopy

Microtubules are polymers of &#945;&#946;-tubulin heterodimers that organize into distinct structures in cells. Microtubule-based architectures and networks often contain subsets of microtubule arrays that differ in their dynamic properties. For example, in dividing cells, stable bundles of crosslinked microtubules coexist in close proximity to dynamic non-crosslinked microtubules. TIRF-microscopy-based in vitro reconstitution studies enable the simultaneous visualization of the dynamics of these different microtubule arrays. In this assay, an imaging chamber is assembled with surface-immobilized microtubules, which are either present as single filaments or organized into crosslinked&#160;bundles. Introduction of tubulin, nucleotides, and protein regulators allows direct visualization of associated proteins and of dynamic properties of single and crosslinked microtubules. Furthermore, changes that occur as dynamic single microtubules organize into bundles can be monitored in real-time. The method described here allows for a systematic evaluation of the activity and localization of individual proteins, as well as synergistic effects of protein regulators on two different microtubule subsets under identical experimental conditions, thereby providing mechanistic insights that are inaccessible by other methods.

Simultaneous Visualization of the Dynamics of Crosslinked and Single Microtubules In Vitro by TIRF Microscopy

Here, a TIRF microscopy-based in vitro reconstitution assay is presented to simultaneously quantify and compare the dynamics of two microtubule populations. A method is described to simultaneously view the collective activity of multiple microtubule-associated proteins on crosslinked microtubule bundles and single microtubules.

Simultane Visualisierung der Dynamik von vernetzten und einzelnen Mikrotubuli in vitro mittels TIRF-Mikroskopie

Microtubules are polymers of &#945;&#946;-tubulin heterodimers that organize into distinct structures in cells. Microtubule-based architectures and ...

Biochemie

Through the Looking Glass: Time-lapse Microscopy and Longitudinal Tracking of Single Cells to Study Anti-cancer Therapeutics

The response of single cells to anti-cancer drugs contributes significantly in determining the population response, and therefore is a major contributing factor in the overall outcome. Immunoblotting, flow cytometry and fixed cell experiments are often used to study how cells respond to anti-cancer drugs. These methods are important, but they have several shortcomings. Variability in drug responses between cancer and normal cells, and between cells of different cancer origin, and transient and rare responses are difficult to understand using population averaging assays and without being able to directly track and analyze them longitudinally. The microscope is particularly well suited to image live cells. Advancements in technology enable us to routinely image cells at a resolution that enables not only cell tracking, but also the observation of a variety of cellular responses. We describe an approach in detail that allows for the continuous time-lapse imaging of cells during the drug response for essentially as long as desired, typically up to 96 hr. Using variations of the approach, cells can be monitored for weeks. With the employment of genetically encoded fluorescent biosensors numerous processes, pathways and responses can be followed. We show examples that include tracking and quantification of cell growth and cell cycle progression, chromosome dynamics, DNA damage, and cell death. We also discuss variations of the technique and its flexibility, and highlight some common pitfalls.

Here, we describe a method of long-term time-lapse microscopy to longitudinally track single cells in response to anti-cancer therapeutics.

Durch den Spiegel: Zeitraffer-Mikroskopie und Longitudinal-Tracking von Einzelzellen Anti-Krebs-Therapeutika zu studieren

The response of single cells to anti-cancer drugs contributes significantly in determining the population response, and therefore is a major contributing ...

Extended Time-lapse Intravital Imaging of Real-time Multicellular Dynamics in the Tumor Microenvironment

In the tumor microenvironment, host stromal cells interact with tumor cells to promote tumor progression, angiogenesis, tumor cell dissemination and metastasis. Multicellular interactions in the tumor microenvironment can lead to transient events including directional tumor cell motility and vascular permeability. Quantification of tumor vascular permeability has frequently used end-point experiments to measure extravasation of vascular dyes. However, due to the transient nature of multicellular interactions and vascular permeability, the kinetics of these dynamic events cannot be discerned. By labeling cells and vasculature with injectable dyes or fluorescent proteins, high-resolution time-lapse intravital microscopy has allowed the direct, real-time visualization of transient events in the tumor microenvironment. Here we describe a method for using multiphoton microscopy to perform extended intravital imaging in live mice to directly visualize multicellular dynamics in the tumor microenvironment. This method details cellular labeling strategies, the surgical preparation of a mammary skin flap, the administration of injectable dyes or proteins by tail vein catheter and the acquisition of time-lapse images. The time-lapse sequences obtained from this method facilitate the visualization and quantitation of the kinetics of cellular events of motility and vascular permeability in the tumor microenvironment.

This protocol describes the use of multiphoton microscopy to perform extended time-lapse imaging of multicellular interactions in real time, in vivo at single cell resolution.

Erweiterte Zeitraffer-Intravital Imaging von Echtzeit-Vielzellige Dynamics im Tumormikromilieu

In the tumor microenvironment, host stromal cells interact with tumor cells to promote tumor progression, angiogenesis, tumor cell dissemination and ...