Name: evaluation of lung metastasis in mouse mammary tumor models by quantitative real-time pcr
Uploaded: 2016-01-29T00:00:00
Description: Watch this Scientific Journal Video about Evaluation of Lung Metastasis in Mouse Mammary Tumor Models by Quantitative Real-time PCR at JoVE.com

The Yeh lab is supported by research funding from an American Cancer Society Institutional Research Grant (IRG-97-219-14) awarded to the Hollings Cancer Center at MUSC, by research funding from a Department of Defense grant (W81XWH-11-2-0229) at MUSC, and by an award from the Concern Foundation (to ESY).

The protocol follows the guidelines and animal care standards of the Medical University of South Carolina (MUSC) and its Institutional Animal Care and Use Committee (IACUC).
1. Lung Dissection
<ol>
	<li>Mammary tumor dissection (optional depending on study goals and whether primary tumor analysis or tail vein injection was performed).
	<ol>
		<li>Euthanize mouse using a lethal dose of isoflurane anesthesia according to IACUC and university regulation. Confirm euthanization by surgical dislocation.&#160;</li>
		<...

<ol>
	<li>Gupta, G. P., Massague, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cancer+metastasis:+building+a+framework.">Cancer metastasis: building a framework.</a> Cell. 127 (4), 679-695 (2006).</li><li>Bos, P. D., Nguyen, D. X., Massague, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modeling+metastasis+in+the+mouse.">Modeling metastasis in the mouse.</a> Curr Opin Pharmacol. 10 (5), 571-577 (2010).</li><li>Kim, I. S., Baek, S. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+models+for+breast+cancer+metastasis.">Mouse models for breast cancer metastasis.</a> Biochem Biophys Res Commun. 394 (3), 443-447 (2010).</li><li>Saxena, M., Christofori, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rebuilding+cancer+metastasis+in+the+mouse.">Rebuilding cancer metastasis in the mouse.</a> Mol Oncol. 7 (2), 283-296 (2013).</li><li>Yang, S., Zhang, J. J., Huang, X. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+models+for+tumor+metastasis.">Mouse models for tumor metastasis.</a> Methods Mol Biol. 928, 221-228 (2012).</li><li>Rampetsreiter, P., Casanova, E., Eferl, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetically+modified+mouse+models+of+cancer+invasion+and+metastasis.">Genetically modified mouse models of cancer invasion and metastasis.</a> Drug Discov Today Dis Models. 8 (2-3), 67-74 (2011).</li><li>Condeelis, J., Segall, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intravital+imaging+of+cell+movement+in+tumours.">Intravital imaging of cell movement in tumours.</a> Nat Rev Cancer. 3 (12), 921-930 (2003).</li><li>Massoud, T. F., Gambhir, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+imaging+in+living+subjects:+seeing+fundamental+biological+processes+in+a+new+light.">Molecular imaging in living subjects: seeing fundamental biological processes in a new light.</a> Genes Dev. 17 (5), 545-580 (2003).</li><li>Zinn, K. R., 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=Noninvasive+bioluminescence+imaging+in+small+animals.">Noninvasive bioluminescence imaging in small animals.</a> ILAR J. 49 (1), 103-115 (2008).</li><li>Tseng, J. C., Kung, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+bioluminescence+imaging+of+mouse+tumor+models.">Quantitative bioluminescence imaging of mouse tumor models.</a> Cold Spring Harb Protoc. 2015 (1), (2015).</li><li>Radonic, 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=Guideline+to+reference+gene+selection+for+quantitative+real-time+PCR.">Guideline to reference gene selection for quantitative real-time PCR.</a> Biochem Biophys Res Commun. 313 (4), 856-862 (2004).</li></ol>

This protocol describes use of QRT-PCR to evaluate mammary tumor cell metastasis to the lung using a xenograft mouse model. It is acknowledged that other techniques, including bioluminescent imaging, are available and are also effective for detecting metastasis despite having their own values and limitations. The data presented suggests that QRT-PCR provides an effective measure of detecting tumor-derived mRNA within lung tissue for quantitation of total metastasis. It is proposed that QRT-PCR analysis provides a seconda...

QRT-PCR analysis is proposed as a method for assessing tumor metastasis. This method is proposed as an alternative for users that are interested in evaluating metastasis but may not have access to specific equipment such as in vivo imaging equipment or a fluorescence capable stereoscope. A discussion of commonly used methods is presented followed by a demonstration for how QRT-PCR analysis can be used either as a separate or as a companion method to evaluate metastasis. This procedure has the potential to provide a quantitative analysis of metastatic burden.
Standard methods of gross analysis, including visualization of lungs under a stereomicroscope as well as serial sectioning followed by hematoxylin and eosin (H&#38;E) staining of lung tissue, are quantifiable but rely heavily on user defined parameters for counting 2-5. When evaluating whole lungs using a stereomicroscope, only large surface metastases are visible and analysis requires the investigator to have reasonable knowledge of lung anatomical structure to determine what constitutes a metastatic lesion. Fluorescent labeling of tumor cells with a marker such as GFP and use of a stereomicroscope that contains a light cube with the appropriate excitation/emission maxima (e.g. near 470/510 nm for GFP) assists in this process, but only surface tumor nodules are detectable. Additionally, fluorescence from blood contamination, which is visible under the same parameters as GFP, may lead to false identification of possible metastatic lesions.
Sectioning of the lung followed by H&#38;E staining to visualize lung metastasis is a useful method to evaluate micrometastases and other microscopic processes including immune cell infiltration but often requires use of the entire lung tissue for paraffin embedding, sectioning, and staining procedures. Therefore, downstream procedures are not ideal following this method. Although quantifiable, this procedure requires the investigator to evaluate a large number of stained lung sections per animal to ensure that the analysis accounts for the entire 3D structure of the lung. Consequently, this type of examination is time consuming, can lead to counting error, and analysis relies heavily on investigator discretion.
Several in vivo imaging techniques (e.g. MRI, PET, SPECT) are currently used to perform or test biological processes in experimental rodent models 8. In vivo bioluminescent imaging is a common method used to acquire a gross view of metastasis 9. This technique is generally applied to evaluate the presence of luciferase reporter activity due to the accumulation of tumor cells, which are engineered to contain a luciferase response element, that reside in specific organs like the mammary gland after tumor cell implantation and the lung upon spontaneous metastasis 10. Visualization of luciferase reporter activity is induced by the presence of luciferin substrate (D-luciferin). Luciferase catalyzes the oxidative decarboxylation of D-luciferin to oxyluciferin generating bioluminescence. While informative, this method is limited by several factors including substrate stability (i.e. short half-life), adequate distribution of substrate which depends on how it is delivered to experimental animals, and low sensitivity of detection 9. A main merit to this technique is that it is non-invasive, can be performed on live animals, and can lead to the detection of tumor cell metastases in multiple organs that may not have been normally harvested at dissection 9,10.
One positive aspect of in vivo imaging techniques is that the lung tissue is undisturbed allowing for secondary procedures like paraffin embedding or as presented here, QRT-PCR analysis. However, because QRT-PCR is theoretically a more sensitive measure of detection, gross evaluation may not reveal low numbers of tumor cells present in the lung. While useful, the imaging techniques described above can be substituted or supplemented with the QRT-PCR method currently described. QRT-PCR has the potential to provide a sensitive measure of tumor-derived mRNA within a lung.

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		<tr>
			<td>2-mercaptoethanol</td>
			<td>Fisher</td>
			<td>BP176-100</td>
			<td></td>
		</tr>
		<tr>
			<td>DNAse</td>
			<td>Thermo Scientific</td>
			<td>EN0521</td>
			<td></td>
		</tr>
		<tr>
			<td>GeneJet RNA Isolation Kit</td>
			<td>Thermo Scientific</td>
			<td>K0732</td>
			<td></td>
		</tr>
		<tr>
			<td>iScript Reverse Transcription Supermix for QRT-PCR</td>
			<td>Bio-Rad</td>
			<td>1708841</td>
			<td></td>
		</tr>
		<tr>
			<td>iTaq Universal SYBR Green Supermix&#160;</td>
			<td>Bio-Rad</td>
			<td>172-5121&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>PrimePCR SYBR Green Assay: ERBB2, Human&#160;</td>
			<td>Bio-Rad</td>
			<td>100-25636&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>PrimePCR Template for SYBR Green Assay: ERBB2, Human&#160;</td>
			<td>Bio-Rad</td>
			<td>100-25716&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>gapdh Primer Sequence</td>
			<td></td>
			<td></td>
			<td>For-ATGGTGAAGGTCGGTGTGAACG Rev-CGCTCCTGGAAGATGGTGATGG</td>
		</tr>
	</tbody>
</table>

evaluation of lung metastasis in mouse mammary tumor models by quantitative real-time pcr

Metastatic disease is the spread of malignant tumor cells from the primary cancer site to a distant organ and is the primary cause of cancer associated death 1. Common sites of metastatic spread include lung, lymph node, brain, and bone 2. Mechanisms that drive metastasis are intense areas of cancer research. Consequently, effective assays to measure metastatic burden in distant sites of metastasis are instrumental for cancer research. Evaluation of lung metastases in mammary tumor models is generally performed by gross qualitative observation of lung tissue following dissection. Quantitative methods of evaluating metastasis are currently limited to ex vivo and in vivo imaging based techniques that require user defined parameters. Many of these techniques are at the whole organism level rather than the cellular level 3-6. Although newer imaging methods utilizing multi-photon microscopy are able to evaluate metastasis at the cellular level 7, these highly elegant procedures are more suited to evaluating mechanisms of dissemination rather than quantitative assessment of metastatic burden. Here, a simple in vitro method to quantitatively assess metastasis is presented. Using quantitative Real-time PCR (QRT-PCR), tumor cell specific mRNA can be detected within the mouse lung tissue.

Beyond the time it takes to perform the initial inoculation of tumor cells into the experimental animal and if performing, primary in vivo tumor analysis, the tissue harvest, RNA isolation, and QRT-PCR analysis is a 1-2 day procedure (Figure 1).
An example of gross analysis is bioluminescent imaging to evaluate tumor cells within the lung tissue. Here, a mammary tumorigenesis experiment was performed to...

Watch this Scientific Journal Video about Evaluation of Lung Metastasis in Mouse Mammary Tumor Models by Quantitative Real-time PCR at JoVE.com

Evaluation of Lung Metastasis in Mouse Mammary Tumor Models by Quantitative Real-time PCR (Video) | JoVE

This protocol describes how to use quantitative Real-time PCR (QRT-PCR) to detect tumor cell specific mRNA representing metastasis within the mouse lung tissue.

Evaluation of Lung Metastasis in Mouse Mammary Tumor Models by Quantitative Real-time PCR

Metastatic disease is the spread of malignant tumor cells from the primary cancer site to a distant organ and is the primary cause of cancer associated ...

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