Name: live-imaging of breast epithelial cell migration after the transient depletion of tip60
Uploaded: 2017-12-07T13:00:00
Description: Watch this Scientific Journal Video about Live-imaging of Breast Epithelial Cell Migration After the Transient Depletion of TIP60 at JoVE.com

We thank the members of the Jha laboratory for their helpful discussion and comments. S.J. was supported by grants from the National Research Foundation Singapore and the Singapore Ministry of Education under its Research Centers of Excellence initiative to the Cancer Science Institute of Singapore (R-713-006-014-271), the National Medical Research Council (CBRG-NIG; BNIG11nov001 and CS-IRG; R-713-000-162-511), the Ministry of Education Academic Research Fund (MOE AcRF Tier 1 T1-2012 Oct -04). Y.Z., G.S.C., and C.Y.T. were supported by a post-graduate fellowship awarded by the Cancer Science Institute of Singapore, National University of Singapore.

1. Preparation
<ol>
	<li>Prepare MCF10A culture medium: Dulbecco&#39;s Modified Eagle Medium (DMEM)/F12 (1:1) with 5% horse serum, 20 ng/mL epithelial growth factor, 0.5 mg/mL hydrocortisone, 100 ng/mL cholera toxin, and 10 &#181;g/mL insulin.</li>
	<li>Prepare serum-free medium: DMEM/F12 (1:1) with 20 ng/mL epithelial growth factor, 0.5 mg/mL hydrocortisone, 100 ng/mL cholera toxin, and 10 &#181;g/mL insulin.</li>
	<li>Use the following siRNA sequence: 
	siControl: 
	Forward: 5&#39;-CGUACGCGGAAUACUUCGAdTdT-3...

<ol>
	<li>Sun, Y., Jiang, X., Chen, S., Fernandes, N., Price, B. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+role+for+the+Tip60+histone+acetyltransferase+in+the+acetylation+and+activation+of+ATM.">A role for the Tip60 histone acetyltransferase in the acetylation and activation of ATM.</a> Proc Natl Acad Sci U S A. 102 (37), 13182-13187 (2005).</li><li>Sykes, S. M., Stanek, T. J., Frank, A., Murphy, M. E., McMahon, S. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Acetylation+of+the+DNA+binding+domain+regulates+transcription-independent+apoptosis+by+p53.">Acetylation of the DNA binding domain regulates transcription-independent apoptosis by p53.</a> J Biol Chem. 284 (30), 20197-20205 (2009).</li><li>Jha, S., Shibata, E., Dutta, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+Rvb1/Tip49+is+required+for+the+histone+acetyltransferase+activity+of+Tip60/NuA4+and+for+the+downregulation+of+phosphorylation+on+H2AX+after+DNA+damage.">Human Rvb1/Tip49 is required for the histone acetyltransferase activity of Tip60/NuA4 and for the downregulation of phosphorylation on H2AX after DNA damage.</a> Mol Cell Biol. 28 (8), 2690-2700 (2008).</li><li>Sapountzi, V., Logan, I. R., Robson, C. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellular+functions+of+TIP60.">Cellular functions of TIP60.</a> Int J Biochem Cell Biol. 38 (9), 1496-1509 (2006).</li><li>Squatrito, M., Gorrini, C., Amati, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tip60+in+DNA+damage+response+and+growth+control:+many+tricks+in+one+HAT.">Tip60 in DNA damage response and growth control: many tricks in one HAT.</a> Trends Cell Biol. 16 (9), 433-442 (2006).</li><li>Sun, Y., Xu, Y., Roy, K., Price, B. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=DNA+damage-induced+acetylation+of+lysine+3016+of+ATM+activates+ATM+kinase+activity.">DNA damage-induced acetylation of lysine 3016 of ATM activates ATM kinase activity.</a> Mol Cell Biol. 27 (24), 8502-8509 (2007).</li><li>Sykes, S. 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=Acetylation+of+the+p53+DNA-binding+domain+regulates+apoptosis+induction.">Acetylation of the p53 DNA-binding domain regulates apoptosis induction.</a> Mol Cell. 24 (6), 841-851 (2006).</li><li>Tang, Y., Luo, J., Zhang, W., Gu, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tip60-dependent+acetylation+of+p53+modulates+the+decision+between+cell-cycle+arrest+and+apoptosis.">Tip60-dependent acetylation of p53 modulates the decision between cell-cycle arrest and apoptosis.</a> Mol Cell. 24 (6), 827-839 (2006).</li><li>Chen, G., Cheng, Y., Tang, Y., Martinka, M., Li, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+Tip60+in+human+melanoma+cell+migration,+metastasis,+and+patient+survival.">Role of Tip60 in human melanoma cell migration, metastasis, and patient survival.</a> J Invest Dermatol. 132 (11), 2632-2641 (2012).</li><li>Gorrini, C., 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=Tip60+is+a+haplo-insufficient+tumour+suppressor+required+for+an+oncogene-induced+DNA+damage+response.">Tip60 is a haplo-insufficient tumour suppressor required for an oncogene-induced DNA damage response.</a> Nature. 448 (7157), 1063-1067 (2007).</li><li>Jha, S., 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=Destabilization+of+TIP60+by+human+papillomavirus+E6+results+in+attenuation+of+TIP60-dependent+transcriptional+regulation+and+apoptotic+pathway.">Destabilization of TIP60 by human papillomavirus E6 results in attenuation of TIP60-dependent transcriptional regulation and apoptotic pathway.</a> Mol Cell. 38 (5), 700-711 (2010).</li><li>Kim, J. H., 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=Transcriptional+regulation+of+a+metastasis+suppressor+gene+by+Tip60+and+beta-catenin+complexes.">Transcriptional regulation of a metastasis suppressor gene by Tip60 and beta-catenin complexes.</a> Nature. 434 (7035), 921-926 (2005).</li><li>Sakuraba, K., 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=Down-regulation+of+Tip60+gene+as+a+potential+marker+for+the+malignancy+of+colorectal+cancer.">Down-regulation of Tip60 gene as a potential marker for the malignancy of colorectal cancer.</a> Anticancer Res. 29 (10), 3953-3955 (2009).</li><li>Subbaiah, V. K., 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=E3+ligase+EDD1/UBR5+is+utilized+by+the+HPV+E6+oncogene+to+destabilize+tumor+suppressor+TIP60.">E3 ligase EDD1/UBR5 is utilized by the HPV E6 oncogene to destabilize tumor suppressor TIP60.</a> Oncogene. , (2015).</li><li>Friedl, P., Wolf, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tumour-cell+invasion+and+migration:+diversity+and+escape+mechanisms.">Tumour-cell invasion and migration: diversity and escape mechanisms.</a> Nat Rev Cancer. 3 (5), 362-374 (2003).</li><li>Nguyen, D. X., Bos, P. D., 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=Metastasis:+from+dissemination+to+organ-specific+colonization.">Metastasis: from dissemination to organ-specific colonization.</a> Nat Rev Cancer. 9 (4), 274-284 (2009).</li><li>Zijl, F., Krupitza, G., Mikulits, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Initial+steps+of+metastasis:+cell+invasion+and+endothelial+transmigration.">Initial steps of metastasis: cell invasion and endothelial transmigration.</a> Mutat Res. 728 (1-2), 23-34 (2011).</li><li>Lamouille, S., Xu, J., Derynck, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+mechanisms+of+epithelial-mesenchymal+transition.">Molecular mechanisms of epithelial-mesenchymal transition.</a> Nat Rev Mol Cell Biol. 15 (3), 178-196 (2014).</li><li>Liang, C. C., Park, A. Y., Guan, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vitro+scratch+assay:+a+convenient+and+inexpensive+method+for+analysis+of+cell+migration+in+vitro.">In vitro scratch assay: a convenient and inexpensive method for analysis of cell migration in vitro.</a> Nat Protoc. 2 (2), 329-333 (2007).</li><li>Zhang, Y., 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=TIP60+inhibits+metastasis+by+ablating+DNMT1-SNAIL2-driven+epithelial-mesenchymal+transition+program.">TIP60 inhibits metastasis by ablating DNMT1-SNAIL2-driven epithelial-mesenchymal transition program.</a> J Mol Cell Biol. , (2016).</li><li>Riahi, R., Yang, Y., Zhang, D. D., Wong, P. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advances+in+wound-healing+assays+for+probing+collective+cell+migration.">Advances in wound-healing assays for probing collective cell migration.</a> J Lab Autom. 17 (1), 59-65 (2012).</li><li>Jonkman, J. 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=An+introduction+to+the+wound+healing+assay+using+live-cell+microscopy.">An introduction to the wound healing assay using live-cell microscopy.</a> Cell Adh Migr. 8 (5), 440-451 (2014).</li></ol>

It is known that in the process of cell migration, cells can either move in the form of adherent sheets; loose clusters; or single, isolated cells. The mode and dynamic of cell invasion can vary from one condition to another, and the phenotype can change within hours. The traditional wound-healing assay is based on snapshot pictures taken from a microscope with a long time interval, such as 12 or 24 h. This makes it difficult to capture the dynamic of wound closure and the pattern of cell movements.
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HIV-Tat-interactive protein 60 kDa (TIP60) is a lysine acetyltransferase that can acetylate both histone and non-histone proteins1,2. Its functions are found to have implications in multiple signaling pathways, including transcription, DNA-damage repair, and apoptosis1,3,4,5,6,7,8. Furthermore, TIP60 is often downregulated in cancers, and its downregulation is correlated with cancer metastasis and poor survival rates9,10,11,12,13,14. Tumor metastasis is the major cause of cancer-related death. It is a multi-step process, and the initial step of metastasis involves the migration and invasion of tumor cells into adjacent tissues15,16. In order to do so, tumor cells first must detach from the primary tumor mass, either in the form of a collectively invading cell sheet or as detached single cells17. During this process, tumor cells often undergo epithelial to mesenchymal transition (EMT), resulting in changes in morphology and cell adhesion capability17,18.
A few techniques have been developed to study the migration and invasion ability of tumor cells in vitro. Among them, the wound-healing assay is the most efficient and economical19. First, this method involves the creation of an artificial gap on a confluent monolayer of cells, thus allowing cells to migrate and close the gap. Second, images of the gaps can be captured at the beginning and end of the experiment. Finally, a comparison of gap closure is used to determine the rate of cell migration. A phase-contrast microscope is usually used to capture images for conventional wound-healing assays. Another advantage of the wound-healing assay is that it partly resembles in vivo tumor cell migration. Similarly to in vivo tumor metastasis, cell migration in wound-healing assays shows both the collective migration of epithelial sheets and the migration of detached single cells.
However, cell migration is known to be dynamic, and there is a need to document the movement of cells in real time. For instance, a conventional wound-healing assay does not allow a researcher to analyze single-cell movement. On the other hand, cells cultured for wound-healing assays are often serum-starved to inhibit cell proliferation. This is done to rule out the possibility of gap closure due to cell proliferation. Nonetheless, there will still be some proliferation and cell death, and phase-contrast images taken before and after the experiment are unable to differentiate between them.
The live-cell imaging technique addresses this limitation of conventional wound-healing assays. Using a live-imaging microscope combined with a CO2 incubator and appropriate temperature control, researchers can measure the gap size and its rate of closure over time while tracing the movement of actively migrating cells located at the tips of the invasive front. Hence, the implementation of live-cell imaging to monitor cell migration will not only provide better visualization of cell migration, but will also allow for the possibility to differentiate between cell migration and cell proliferation, thus providing a more reliable analysis of cell migration.
In this study, MCF10A breast epithelial cells were used to demonstrate the combination of the wound-healing assay and live-cell imaging to study the role of TIP60 in cell migration. The depletion of TIP60 results in increased migration abilities in MCF10A cells.

<table border="0" cellpadding="0" cellspacing="0" width="874">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">MCF10A cell</td>
			<td style="width:211px;">ATCC</td>
			<td style="width:119px;">CRL-10317TM</td>
			<td style="width:257px;">Breast epithelial cell</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">DMEM/F12 media (1:1)</td>
			<td style="width:211px;">Gibco</td>
			<td style="width:119px;">11330-032</td>
			<td>MCF10A culture media</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Epithelial growth factor (EGF)</td>
			<td style="width:211px;">Peprotech</td>
			<td style="width:119px;">AF-100-15</td>
			<td>Supplements for MCF10A culture media</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Cholera Toxin</td>
			<td style="width:211px;">Sigma-Aldrich</td>
			<td style="width:119px;">C-8052</td>
			<td>Supplements for MCF10A culture media</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Hydrocortisone</td>
			<td style="width:211px;">Sigma-Aldrich</td>
			<td style="width:119px;">H-0888</td>
			<td>Supplements for MCF10A culture media</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Insulin</td>
			<td style="width:211px;">Sigma-Aldrich</td>
			<td style="width:119px;">I-1882</td>
			<td>Supplements for MCF10A culture media</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">House serum</td>
			<td style="width:211px;">Gibco</td>
			<td style="width:119px;">16050-122</td>
			<td>Supplements for MCF10A culture media</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Trypsin</td>
			<td style="width:211px;">Gibco</td>
			<td style="width:119px;">25200-056</td>
			<td>For MCF10A detach from plate</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Hemacytometer</td>
			<td style="width:211px;">Fisher Scientific</td>
			<td style="width:119px;">267110</td>
			<td>For counting cell</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Opti-MEM reduced serum media</td>
			<td style="width:211px;">Gibco</td>
			<td style="width:119px;">31985-070</td>
			<td>For siRNA mixture</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Lipofectamine RNAiMAX</td>
			<td style="width:211px;">Invitrogen/Life Technologies</td>
			<td style="width:119px;">56532</td>
			<td>Transfect reagent</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Trizol reagent</td>
			<td style="width:211px;">Invitrogen/Life Technologies</td>
			<td style="width:119px;">15596-026</td>
			<td>For mRNA extraction</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">iScript cDNA Synthesis Kit</td>
			<td style="width:211px;">Bio-Rad</td>
			<td style="width:119px;">170-8891</td>
			<td>For cDNA generation</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">iTaq Universal SYBR Green Supermix</td>
			<td style="width:211px;">Bio-Rad</td>
			<td style="width:119px;">172-5125</td>
			<td>For real time qPCR</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">7500 Fast Real Time PCR system</td>
			<td style="width:211px;">Biosystems</td>
			<td style="width:119px;"></td>
			<td>Real time qPCR mechine</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">10-cm dish</td>
			<td style="width:211px;">Greiner bio-one</td>
			<td style="width:119px;">664160</td>
			<td>For Knockdown experiment</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">24-well plate</td>
			<td style="width:211px;">Cellstar</td>
			<td style="width:119px;">662160</td>
			<td>For wound healing assay</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">siControl siRNA</td>
			<td style="width:211px;">Self designed</td>
			<td style="width:119px;">Self designed</td>
			<td>CGUACGCGGAAUACUUCGAdTdT</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">siTIP60 siRNA</td>
			<td style="width:211px;">Self designed</td>
			<td style="width:119px;">Self designed</td>
			<td>UGAUCGAGUUCAGCUAUGAdTdT</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Live cell observer</td>
			<td style="width:211px;">Zeiss</td>
			<td style="width:119px;"></td>
			<td>Zeiss inverted Cell Observer for live cell experiments</td>
		</tr>
	</tbody>
</table>

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.

General Schema of Live-cell Imaging-based Cell Migration Assay 
Figure 1A is a schema of this protocol. MCF10A cells transfected with siControl showed typical epithelial morphology. After the depletion of TIP60, MCF10A cells were more mesenchymal compared to control cells (Figure 1B).
Examination of TIP60 Knockdown Efficiency ...

Watch this Scientific Journal Video about Live-imaging of Breast Epithelial Cell Migration After the Transient Depletion of TIP60 at JoVE.com

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

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.

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 ...

The overall goal of this procedure is to observe the effects of the depletion of specific genes of interest on cell migration. This method can help us answer key questions in cancer metastasis, such as cancer cell migration. The main advantage of this technique is that it allows the dynamic cell migration to be monitored in real time.We first had the idea for this method, when we were observing cell morphology changes upon the patient of TIP60, a tumor suppressor. Begin by seeding one million breast epithelial cells in three milliliters of culture medium per 10 centimeter dish. Add 20 minutes room temperature incubated SRINA mixture drop by drop to the experimental cell culture.Manually shake both dishes to ensure that the cells are evenly distributed before placing them into a 37 degree Celsius incubator. After six hours, replace the supernatants with eight milliliters of fresh culture medium per dish and return the cultures to the incubator. The next morning, replace the supernatants with three milliliters of fresh culture medium per dish and add a second patch of SIRNA mixture to the experimental cell culture, as just demonstrated, shaking the dish to ensure the reagents are fully mixed before returning the cells to the incubator.Then replace the supernatants with eight milliliters of fresh culture medium after six hours and incubate the cultures over night. On day three, wash the cells one time with two milliliters of BPS per plate and detach the cells in both plates with one milliliter of tripson EDTA per dish for 20 minutes at 37 degrees Celsius. At the end of the incubation, stop the reaction with four milliliters of complete culture medium per plate.Resuspend the cells by pipetting and transfer the cell suspensions into individual 15 milliliter tubes. Collect the cells by centrifugation and resuspend the pellets in five milliliters of serum-free medium per tube. After counting, dilute both cell cultures to a 600, 000 cells per milliliter concentration and add 500 microliters of cells from each culture to one well of a 24 well plate to ensure 100%confluency.When all of the cells have been seeded, gently shake the plate back and forth and side to side to ensure even distribution and place the plate in the cell culture incubator for 24 hours. To check the knock down efficiency of the gene of interest, collect the remaining cells in the collection tubes with another centrifugation and isolate the RNA from the pellets, using a commercial reagent according to the manufacturers instructions for real time quantitative PCR evaluation. The next morning, at least one hour before beginning the live cell imaging, turn on the microscope and temperature control.Set the temperature to 37 degrees Celsius and carbon dioxide gas supply to 5%When the chamber has reached 37 degrees Celsius, use phase contrast microscopy to confirm that the cells are confluent and fully attached to the bottom of the wells. Then use a 200 microliter pipette tip to gently scratch a straight line across the entire length of the center of each well and gently wash all of the wells five times with serum free medium to remove the detached cells. After the last wash, add one milliliter of serum free medium to each well.Place the plate on the microscope stage under the 10 power objective and direct the emitted light to the eye pieces instead of the camera. Manually adjust the focus to locate each wound and the cells around it. Then return the emitted light back to the camera and use a live cell observing system to mark the position of the wounds and to set the time conditions.Image the cells for the appropriate experiment period, then open the first avi video in the appropriate imaging software and open the m track j plug-in. Click on the add tab to add a track for the single cells and choose one cell at the tip of the invasive front and one cell that can migrate on its own. Follow the movement of the chosen cells on the video using mtrackJ to trace their trafficking.Then click on the measure tab to measure the distance of the cell movement and save the videos with the tracks in avi format. After depletion of TIP60, breast epithelial cells are more mesenchymal compared to control cultured cells. Indeed, TIP60 expression, as well as epithelial cell adhesion molecule expression, decreases significantly after siTIP60 treatment.On the other hand, the expression of specific epithelial to mesenchymal transition driver genes is increased upon TIP60 depletion. Live imaging of the cell cultures after wound administration demonstrates a faster cell migration of siTIP60 treated cells, compared to siControl cultures, with a significant increase in the percentage of migrating cells observed in response to TIP60 depletion. Further, siControl cells move as a sheet, whereas more single cell movement is observed within the siTIP60 cultures.After watching this video, you should have a good understanding of how to use a live cell imaging technique to monitor dynamic changes of cell migration.

live-imaging-breast-epithelial-cell-migration-after-transient

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Utilizing Functional Genomics Screening to Identify Potentially Novel Drug Targets in Cancer Cell Spheroid Cultures

The identification of functional driver events in cancer is central to furthering our understanding of cancer biology and indispensable for the discovery of the next generation of novel drug targets. It is becoming apparent that more complex models of cancer are required to fully appreciate the contributing factors that drive tumorigenesis in vivo and increase the efficacy of novel therapies that make the transition from pre-clinical models to clinical trials.
Here we present a methodology for generating uniform and reproducible tumor spheroids that can be subjected to siRNA functional screening. These spheroids display many characteristics that are found in solid tumors that are not present in traditional two-dimension culture. We show that several commonly used breast cancer cell lines are amenable to this protocol. Furthermore, we provide proof-of-principle data utilizing the breast cancer cell line BT474, confirming their dependency on amplification of the epidermal growth factor receptor HER2 and mutation of phosphatidylinositol-4,5-biphosphate 3-kinase (PIK3CA) when grown as tumor spheroids. Finally, we are able to further investigate and confirm the spatial impact of these dependencies using immunohistochemistry.

Identifying novel drug targets that transition from pre-clinical testing to human trials is a scientific priority. To that end, here we describe a functional genomics approach for examining the impact of gene depletion on cancer cell line spheroids, which more appropriately model human cancers in vivo.

The identification of functional driver events in cancer is central to furthering our understanding of cancer biology and indispensable for the discovery ...

A Portal Vein Injection Model to Study Liver Metastasis of Breast Cancer

Breast cancer is the leading cause of cancer-related mortality in women worldwide. Liver metastasis is involved in upwards of 30% of cases with breast cancer metastasis, and results in poor outcomes with median survival rates of only 4.8 - 15 months. Current rodent models of breast cancer metastasis, including primary tumor cell xenograft and spontaneous tumor models, rarely metastasize to the liver. Intracardiac and intrasplenic injection models do result in liver metastases, however these models can be confounded by concomitant secondary-site metastasis, or by compromised immunity due to removal of the spleen to avoid tumor growth at the injection site. To address the need for improved liver metastasis models, a murine portal vein injection method that delivers tumor cells firstly and directly to the liver was developed. This model delivers tumor cells to the liver without complications of concurrent metastases in other organs or removal of the spleen. The optimized portal vein protocol employs small injection volumes of 5 - 10 &#956;l, &#8805; 32 gauge needles, and hemostatic gauze at the injection site to control for blood loss. The portal vein injection approach in Balb/c female mice using three syngeneic mammary tumor lines of varying metastatic potential was tested; high-metastatic 4T1 cells, moderate-metastatic D2A1 cells, and low-metastatic D2.OR cells. Concentrations of &#8804; 10,000 cells/injection results in a latency of ~ 20 - 40 days for development of liver metastases with the higher metastatic 4T1 and D2A1 lines, and &#62; 55 days for the less aggressive D2.OR line. This model represents an important tool to study breast cancer metastasis to the liver, and may be applicable to other cancers that frequently metastasize to the liver including colorectal and pancreatic adenocarcinomas.

A surgical procedure was developed to deliver mammary tumor cells to the murine liver via portal vein injection. This model permits investigation of late stages of liver metastasis in a fully immune competent host, including tumor cell extravasation, seeding, survival, and metastatic outgrowth in the liver.

Breast cancer is the leading cause of cancer-related mortality in women worldwide. Liver metastasis is involved in upwards of 30% of cases with breast ...

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.

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.

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

Invasive Behavior of Human Breast Cancer Cells in Embryonic Zebrafish

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

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

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

Using the Dot Assay to Analyze Migration of Cell Sheets

Although complex organisms appear static, their tissues are under a continuous turnover. As cells age, die, and are replaced by new cells, cells move within tissues in a tightly orchestrated manner. During tumor development, this equilibrium is disturbed, and tumor cells leave the epithelium of origin to invade the local microenvironment, to travel to distant sites, and to ultimately form metastatic tumors at distant sites. The dot assay is a simple, two-dimensional unconstrained migration assay, to assess the net movement of cell sheets into a cell-free area, and to analyze parameters of cell migration using time-lapse imaging. Here, the dot assay is demonstrated using a human invasive, lung colony forming breast cancer cell line, MCF10CA1a, to analyze the cells' migratory response to epidermal growth factor (EGF), which is known to increase malignant potential of breast cancer cells and to alter the migratory phenotype of cells.

Cell migration is essential for development, tissue maintenance and repair, and tumorigenesis, and is regulated by growth factors, chemokines, and cytokines. This protocol describes the dot assay, a two-dimensional, unconstrained migration assay to assess the migratory phenotype of attached, cohesive cell sheets in response to microenvironmental cues.

Although complex organisms appear static, their tissues are under a continuous turnover. As cells age, die, and are replaced by new cells, cells move ...

Live-Cell Imaging Assays to Study Glioblastoma Brain Tumor Stem Cell Migration and Invasion

Glioblastoma (GBM) is an aggressive brain tumor that is poorly controlled with the currently available treatment options. Key features of GBMs include rapid proliferation and pervasive invasion into the normal brain. Recurrence is thought to result from the presence of radio- and chemo-resistant brain tumor stem cells (BTSCs) that invade away from the initial cancerous mass and, thus, evade surgical resection. Hence, therapies that target BTSCs and their invasive abilities may improve the otherwise poor prognosis of this disease. Our group and others have successfully established and characterized BTSC cultures from GBM patient samples. These BTSC cultures demonstrate fundamental cancer stem cell properties such as clonogenic self-renewal, multi-lineage differentiation, and tumor initiation in immune-deficient mice. In order to improve on the current therapeutic approaches for GBM, a better understanding of the mechanisms of BTSC migration and invasion is necessary. In GBM, the study of migration and invasion is restricted, in part, due to the limitations of existing techniques which do not fully account for the in vitro growth characteristics of BTSCs grown as neurospheres. Here, we describe rapid and quantitative live-cell imaging assays to study both the migration and invasion properties of BTSCs. The first method described is the BTSC migration assay which measures the migration toward a chemoattractant gradient. The second method described is the BTSC invasion assay which images and quantifies a cellular invasion from neurospheres into a matrix. The assays described here are used for the quantification of BTSC migration and invasion over time and under different treatment conditions.

Here, we describe live-cell imaging techniques to quantitatively measure the migration and invasion of glioblastoma brain tumor stem cells over time and under multiple treatment conditions.

Glioblastoma (GBM) is an aggressive brain tumor that is poorly controlled with the currently available treatment options. Key features of GBMs include ...

Flow Cytometric Detection of Newly-formed Breast Cancer Stem Cell-like Cells After Apoptosis Reversal

Cancer recurrence has long been studied by oncologists while the underlying mechanisms remain unclear. Recently, we and others found that a phenomenon named apoptosis reversal leads to increased tumorigenicity in various cell models under different stimuli. Previous studies have been focused on tracking this process in vitro and in vivo; however, the isolation of real reversed cells has yet to be achieved, which limits our understanding on the consequences of apoptosis reversal. Here, we take advantage of a Caspase-3/7 Green Detection dye to label cells with activated caspases after apoptotic induction. Cells with positive signals are further sorted out by fluorescence-activated cell sorting (FACS) for recovery. Morphological examination under confocal microscopy helps confirm the apoptotic status before FACS. An increase in tumorigenicity can often be attributed to the elevation in the percentage of cancer stem cell (CSC)-like cells. Also, given the heterogeneity of breast cancer, identifying the origin of these CSC-like cells would be critical to cancer treatment. Thus, we prepare breast non-stem cancer cells before triggering apoptosis, isolating caspase-activated cells and performing the apoptosis reversal procedure. Flow cytometry analysis reveals that breast CSC-like cells re-appear in the reversed group, indicating breast CSC-like cells are transited from breast non-stem cancer cells during apoptosis reversal. In summary, this protocol includes the isolation of apoptotic breast cancer cells and detection of changes in CSC percentage in reversed cells by flow cytometry.

Here, we present a protocol to isolate apoptotic breast cancer cells by fluorescence-activated cell sorting and further detect the transition of breast non-stem cancer cells to breast cancer stem cell-like cells after apoptosis reversal by flow cytometry.

Cancer recurrence has long been studied by oncologists while the underlying mechanisms remain unclear. Recently, we and others found that a phenomenon ...

Differentiation of Mouse Breast Epithelial HC11 and EpH4 Cells

Cadherins play an important role in the regulation of cell differentiation as well as neoplasia. Here we describe the origins and methods of the induction of differentiation of two mouse breast epithelial cell lines, HC11 and EpH4, and their use to study complementary stages of mammary gland development and neoplastic transformation.
The HC11 mouse breast epithelial cell line originated from the mammary gland of a pregnant Balb/c mouse. It differentiates when grown to confluence attached to a plastic Petri dish surface in medium containing fetal calf serum and Hydrocortisone, Insulin and Prolactin (HIP medium). Under these conditions, HC11 cells produce the milk proteins &#946;-casein and whey acidic protein (WAP), similar to lactating mammary epithelial cells, and form rudimentary mammary gland-like structures termed &#34;domes&#34;.
The EpH4 cell line was derived from spontaneously immortalized mouse mammary gland epithelial cells isolated from a pregnant Balb/c mouse. Unlike HC11, EpH4 cells can fully differentiate into spheroids (also called mammospheres) when cultured under three-dimensional (3D) growth conditions in HIP medium. Cells are trypsinized, suspended in a 20% matrix consisting of a mixture of extracellular matrix proteins produced by Engelbreth-Holm-Swarm (EHS) mouse sarcoma cells, plated on top of a layer of concentrated matrix coating a plastic Petri dish or multiwell plate, and covered with a layer of 10% matrix-containing HIP medium. Under these conditions, EpH4 cells form hollow spheroids that exhibit apical-basal polarity, a hollow lumen, and produce &#946;-casein and WAP.
Using these techniques, our results demonstrated that the intensity of the cadherin/Rac signal is critical for the differentiation of HC11 cells. While Rac1 is necessary for differentiation and low levels of activated RacV12 increase differentiation, high RacV12 levels block differentiation while inducing neoplasia. In contrast, EpH4 cells represent an earlier stage in mammary epithelial differentiation, which is inhibited by even low levels of RacV12.

We describe techniques for differentiation induction of two breast epithelial lines, HC11 and EpH4. While both require fetal calf serum, insulin, and prolactin to produce milk proteins, EpH4 cells can fully differentiate into mammospheres in three-dimensional culture. These complementary models are useful for signal transduction studies of differentiation and neoplasia.

Cadherins play an important role in the regulation of cell differentiation as well as neoplasia. Here we describe the origins and methods of the induction ...

Evaluating the Differentiation Capacity of Mouse Prostate Epithelial Cells Using Organoid Culture

The prostate epithelium is comprised predominantly of basal and luminal cells. In vivo lineage tracing has been utilized to define the differentiation capacity of mouse prostate basal and luminal cells during development, tissue-regeneration and transformation. However, evaluating cell-intrinsic and extrinsic regulators of prostate epithelial differentiation capacity using a lineage tracing approach often requires extensive breeding and can be cost-prohibitive. In the prostate organoid assay, basal and luminal cells generate prostatic epithelium ex vivo. Importantly, primary epithelial cells can be isolated from mice of any genetic background or mice treated with any number of small molecules prior to, or after, plating into three-dimensional (3D) culture. Sufficient material for evaluation of differentiation capacity is generated after 7-10 days. Collection of basal-derived and luminal-derived organoids for (1) protein analysis by Western blot and (2) immunohistochemical analysis of intact organoids by whole-mount confocal microscopy enables researchers to evaluate the ex vivo differentiation capacity of prostate epithelial cells. When used in combination, these two approaches provide complementary information about the differentiation capacity of prostate basal and luminal cells in response to genetic or pharmacological manipulation.

Mouse prostate organoids represent a promising context to evaluate mechanisms that regulate differentiation. This paper describes an improved approach to establish prostate organoids, and introduces methods to (1) collect protein lysate from organoids, and (2) fix and stain organoids for whole-mount confocal microscopy.

The prostate epithelium is comprised predominantly of basal and luminal cells. In vivo lineage tracing has been utilized to define the differentiation ...

Rat Mammary Epithelial Cell Transplantation into the Interscapular White Fat Pad

As early as the 1970s, researchers have successfully transplanted mammary epithelial cells into the interscapular white fat pad of rats. Grafting mammary epithelium using transplantation techniques takes advantage of the hormonal environment provided by the adolescent rodent host. These studies are ideally suited to explore the impact of various biological manipulations on mammary gland development and dissect many aspects of mammary gland biology. A common, but limiting, feature is that transplanted epithelial cells are strongly influenced by the surrounding stroma and outcompeted by endogenous epithelium; to utilize native mammary tissue, the abdominal-inguinal white fat pad must be cleared to remove host mammary epithelium prior to the transplantation. A major obstacle when using the rat model organism is that clearing the developing mammary tree in post-weaned rats is not efficient. When transplanted into gland-free fat pads, donor epithelial cells can repopulate the cleared host fat pad and form a functional mammary gland. The interscapular fat pad is an alternative location for these grafts. A major advantage is that it lacks ductal structures yet provides the normal stroma that is necessary to promote epithelial outgrowth and is easily accessible in the rat. Another major advantage of this technique is that it is minimally invasive, because it eliminates the need to cauterize and remove the growing endogenous mammary tree. Additionally, the interscapular fat pad contains a medial blood vessel that can be used to separate sites for grafting. Because the endogenous glands remain intact, this technique can also be used for studies comparing the endogenous mammary gland to the transplanted gland. This paper describes the method of mammary epithelial cell transplantation into the interscapular white fat pad of rats.

This article describes a transplantation method to graft donor rat mammary epithelial cells into the interscapular white fat pad of recipient animals. This method can be used to examine host and/or donor effects on mammary epithelium development and eliminates the need for pre-clearing, thereby extending the usefulness of this technique.

As early as the 1970s, researchers have successfully transplanted mammary epithelial cells into the interscapular white fat pad of rats. Grafting mammary ...