We would like to thank Dr. Lee Niswander and Dr. Rada Massarwa for their technical expertise and contributions to the slice culture confocal imaging protocol described here. Further thanks to Dr. Kalen Dionne who provided expertise regarding optimizing brain tumor tissue slicing and culture parameters.

Before collection of patient tissue samples is initiated, informed consent must be obtained from each patient under an approved Institutional Review Board (IRB) protocol. The authors of this protocol received consent for the work described under approved IRB protocols at the University of Colorado Hospital and Inova Fairfax Hospital. Data collected from these slice cultures were not used to direct patient care decisions.
1. Pre-slicing Preparation
<ol>
	<li>Prepare &#34;tissue processing&#34; media and &#34;slice culture maintenance&#34; media the day before planned tumor resection and tissue collection (or utilize previously generated media within 2 weeks). Add 5 mL of Penicillin-Streptomycin solution (10,000 U/mL) and 5 mL of 1 M HEPES to 500 mL of a High-Glucose DMEM to generate the tissue processing medium.</li>
	<li>Prepare 250 mL of slice culture maintenance media using a base of neuronal medium (e.g., Neurobasal) without phenol red. Supplement this medium with 10 mM HEPES, 1x B-27 supplement, 400 &#181;M L-glutamine, 600 &#181;M L-alanyl-L-glutamine dipeptide, 60 U/mL penicillin, 60 &#181;g/mL streptomycin, and 6 U/mL nystatin.</li>
	<li>Store all media at 4 &#176;C for no longer than 2 weeks.</li>
</ol>
2. Day of Surgery: Tissue Acquisition
<ol>
	<li>On the day of tissue acquisition, prepare 50 - 100 mL of 1% and 2% (wt/vol %) solutions of low melting temperature agarose in tissue processing media using autoclaved glassware and sterile technique in a laminar flow hood. Both concentrations of agarose are needed to accommodate unpredictable variation in tumor tissue consistency.</li>
	<li>Heat the agarose suspension, using a microwave, until gentle boiling is observed. Place the agarose solution in a 37 &#176;C water bath to maintain in a liquid state until use.</li>
	<li>Place 1 mL of slice culture maintenance media in each well of a 6-well plate.</li>
	<li>Use a sterile forceps to place empty PTFE culture inserts in each well. Place the plate in a humidified, water-jacketed, tissue culture incubator with a 5% CO2 atmosphere maintained at 37 &#176;C.</li>
	<li>Using a sterile Pasteur pipette in a laminar flow hood, bubble a mixture of 95% O2/5% CO2 gas into a flask containing ice cold tissue processing media for approximately 15 to 30 min, prior to tumor tissue acquisition. The use of supra-oxygenated media minimizes hypoxia in the bulk tissue during processing.</li>
	<li>Prepare labeled 50 mL conical tubes (enough for desired number of individual tumor regions to be isolated) containing 20 mL aliquots of supra-oxygenated ice-cold processing media to transport tissue between the operating room and slicing facility.</li>
	<li>In conjunction with a neurosurgeon, pre-operatively plan the tumor region for sample acquisition. Select a tumor region with contrast enhancement as demonstrated on the patient&#39;s clinical imaging (T1 post-gadolinium magnetic resonance imaging (MRI) sequences). Previous experience suggests this area yields viable tumor tissue as opposed to necrotic tissue. 
	NOTE: Generation of slices from the surrounding (peritumoral) white matter was attempted; however, background autofluorescence and decreased tumor cell density limited the experimental utility of these slices.</li>
	<li>Obtain tumor tissue towards the beginning of tumor resection. Avoid collection of tumor tissue exposed to extensive bipolar cautery, which may compromise tissue viability secondary to thermal injury. Tissue samples acquired during piecemeal tumor resection demonstrate enhanced viability when compared to tissue acquired from lengthy en bloc resections. This observation may relate to differential tumor tissue deprivation of blood flow as a result of surgical resection and extended time to acquisition.</li>
	<li>If desired, label and store tumor tissue in separate conical tubes to isolate samples from distinct tumor regions. (i.e. superficial vs. deep tumor tissue). Precise tissue locations can be recorded if/when intraoperative surgical navigation is available.</li>
</ol>
3. Slice Culture Preparation
NOTE: This protocol requires the use of fresh unfixed human tissue. All samples are presumed to be infectious, and should be handled according to universal blood borne pathogen protocols. Appropriate personal protective equipment should be donned at all times. Forceps and scalpels should be exposed to 15 min of UV light prior to use. During use, intermittently spray the tools with 70% ethanol (EtOH), allowing time for the liquid to evaporate before use. The slicing process is performed in a semi-sterile fashion utilizing a horizontal laminar flow hood with filtered air.
<ol>
	<li>Place tumor tissue pieces in a Petri dish with ice-cold processing media. To wash the tumor tissue and minimize adherent red blood cells, use a pipette to gently exchange and discard the media in the Petri dish three times.</li>
	<li>Using a scalpel, cut tumor pieces into rectangular box shapes. Trim tissue pieces to approximate 3 mm x 3 mm x 10 mm. Carefully remove any attached vessels through excision or gentle traction with fine forceps.</li>
	<li>Pipette 5 - 7 mL of 37 &#176;C agarose into a small cube-shaped (~ 2 cm3) plastic embedding mold. Confirm temperature of agarose solution is no greater than 37 &#176;C with a sterile thermometer before use.</li>
	<li>Allow agarose to sit for approximately 1 min on a bed of ice.</li>
	<li>Place 2 - 4 tumor tissue &#34;strips&#34; into agarose with long axis oriented vertically. 
	NOTE: Tissue strips will tend to &#34;sink&#34; in the agarose before solidification. To avoid this complication, temporarily hold the tissue strip in vertical orientation until agarose is further solidified.</li>
	<li>Keep the tissue containing agarose mold on a bed of ice for 2 - 5 min to facilitate solidification.</li>
	<li>Remove mold from ice and gently remove the agarose block by cutting the sides of the form with a scalpel. Avoid placing excessive force on the block, which may fracture the agarose.</li>
	<li>Use a generous drop of cyanoacrylate glue to affix the agarose block to the vibratome specimen plate. Let glue set for approximately 1 - 2 min.</li>
	<li>Fill the vibratome reservoir with ice-cold processing media to submerge the agarose block affixed to the specimen plate.</li>
	<li>During slicing, bubble 95% O2 / 5% CO2 gas mixture into the vibratome reservoir through a trimmed sterile plastic pipette.</li>
	<li>Set the vibratome slice thickness to 300 - 350 &#181;m.</li>
	<li>Adjust blade advance speed and blade amplitude according to tissue consistency. &#34;Stiffer&#34; GBM tissue requires slower blade advance speeds and higher amplitude. Exact blade speed and amplitude settings will vary according to vibratome specifications. 
	NOTE: Several issues commonly arise during slicing. If the tissue strip dislodges from the agarose block, attempt embedding the tissue in a higher concentration agarose. If tumor slices are thicker than desired (machine set), or are asymmetric, increase the amplitude and decrease speed of vibratome blade. To ensure tumor tissue is not stuck to or &#34;dragged&#34; by the blade holder, as slicing occurs, carefully position the microspatula between the blade holder and slice, as the blade moves.</li>
	<li>Transfer tissue slices to Petri dish with ice-cold processing media using a stainless steel microspatula.</li>
	<li>Obtain 6-well plates containing PTFE inserts and equilibrated slice culture media from incubator (as prepared in section 2, step 4).</li>
	<li>Plate tissue slices using a stainless steel microspatula. Minimize direct contact and manipulation of tissue by using a small fine bristle paintbrush to generate a &#34;fluid wave&#34; to gently push the slice off the spatula and onto the culture insert. 
	NOTE: Minimize the amount of processing media introduced on top of the tissue culture insert. If excessive amounts of media are transferred causing the slices to float, use a sterile Pasteur pipette to remove media.</li>
	<li>Return the 6-well plates containing tumor slices to an incubator maintained at 37 &#176;C with a 5% CO2 atmosphere. 
	NOTE: The entire embedding and slicing protocol should be completed within 90 min of tumor tissue acquisition from the operating room.</li>
</ol>
4. Slice Culture Maintenance
<ol>
	<li>After 12 - 24 h, transfer the slice cultures by grasping each insert rim with a sterile forceps, and transfer to plates containing fresh slice culture maintenance media. Ensure the slice culture maintenance media aliquoted into each well equilibrates in the incubator for at least 15 min before transferring inserts.</li>
	<li>Move inserts to new 6-well plates with fresh equilibrated slice culture media every 48 h.</li>
	<li>If desired, aliquot old slice culture media with a pipette for immediate use in biochemical assays (i.e. ELISA) or freeze at -80 &#176;C for future use.</li>
</ol>
5. Tumor Cell Labeling Via Green Fluorescence Protein Expressing Retrovirus
NOTE: Time-lapse microscopy for analysis of tumor cell migration requires stable, long-term fluorescent labeling of cells within the slice culture. Use of retrovirus is suggested because it selectively infects dividing cells, thereby enriching fluorescent labeling within the tumor cell population as opposed to microglia or other cell types present within the slice. Standardization of infection suggests that a viral titer of 104 CFUs/&#181;L results in sufficient green fluorescent protein expression for the tracking and analysis of cell migration. Increased viral titer, use of non-selective virus (i.e. adenovirus, lentivirus), or other means of labeling all cells may preclude identification of clear cell boundaries during migration, thus complicating analysis. Use of alternative fluorescent markers can be utilized and optimized as needed.
<ol>
	<li>Obtain retrovirus for infection of tumor slices either via standard protocols5,14 or from a commercially available source. Dilute the viral supernatant by adding the appropriate volume into unsupplemented neuronal medium to attain a viral titer of 104 CFUs/&#181;L.</li>
	<li>Between 7 - 10 days of culture infect the tumor slice cultures of interest with 5 - 10 &#181;L of virus (104 CFUs/&#181;L). Place the virus gently dropwise onto the surface of each tissue slice. Decrease supernatant volume added if the slice floats on the surface of the insert. Return plates containing slice cultures to incubator.</li>
	<li>Assess the slices for labeled tumor cells beginning at 24 h after viral infection (see section 6). This time delay will vary dependent on viral incorporation and fluorescence gene expression kinetics. For the viral constructs used here, 72 h was required to observe robust fluorescent signal with a standard epifluorescence microscope. 
	&#8203;NOTE: Rarely, slices display a predominantly peripheral distribution of virally labeled cells, which can complicate confocal imaging. To avoid this complication, attempt to reduce slice thickness and thickness variation across the slice. If the slice culture has a thicker region near the center, this may prevent adequate nutrient penetration, thus limiting the population of actively dividing tumor cells. A qualitative assay to screen for this complication is the addition of a tetrazolium dye reagent (i.e. MTT) to the slice culture media. Areas of the slice that do not turn blue after adding the reagent indicate a lack of metabolic activity and compromised slice health.</li>
</ol>
6. Time-Lapse Single Photon Laser Scanning Confocal Imaging of Tumor Cell Migration
NOTE: After successful transduction and health of the culture is confirmed, cells may be imaged under control conditions, followed by an equal period of imaging under treatment conditions. Using this protocol, cells were successfully imaged and tracked for 12 hours in each condition. However, shorter or longer periods of imaging and environmental manipulation may also be informative.
<ol>
	<li>Loading the Microscope
	<ol>
		<li>Before imaging, place 1 mL of fresh slice media into a glass bottom dish.</li>
		<li>Allow media in the glass bottom dish to equilibrate in an incubator for 15 min. 
		&#8203;NOTE: At this point soluble labeling agents, such as fluorescently conjugated lectins (i.e. Isolectin IB4 for microglia labeling) or ligand conjugated quantum dots, can be added to the slice culture media for identification of cellular subpopulations during imaging.</li>
		<li>Transfer the insert to be imaged to a glass bottom dish using sterile forceps in a laminar flow hood. Transport the dish to the microscope stage.</li>
		<li>Maintain slice cultures at 37 &#176;C and 5% CO2 atmosphere in a sealed microscope stage-top incubator. Utilize sterile H2O humidification of the incubation chamber if available to prevent excessive media evaporation (especially important for longer imaging experiments).</li>
		<li>Utilize a confocal microscope with a long working distance 10X air objective and laser excitation for single-photon and/or multi-photon. 
		&#8203;NOTE: Ensure that the microscope objective lens provides adequate working distance. As a result of the added height from the stage-top incubator, glass bottom dish, and tissue culture insert, long working distance objectives are critical.</li>
		<li>Secure the glass bottom plate, remove the plastic Petri dish cover, and cover with a gas-permeable membrane.</li>
	</ol>
	</li>
	<li>Image Acquisition
	<ol>
		<li>Use the microscope to visually inspect the slice, and locate a suitable field with adequate density of fluorescently labeled tumor cells between the slice edge and the center. Avoid imaging fields at the edge of the slice, due to increased susceptibility of tissue shifts during imaging. Tissue slice harps may be employed to limit this shift.</li>
		<li>Use imaging software in multidimensional analysis mode to set the first (bottom) and last (top) Z-stack boundaries, such that all positions to be imaged contain visible fluorescent cellular signal. Imaging through 150 - 200 &#181;m of the slice, with a constant Z-step of 10 &#181;m provided adequate resolution for tracking cell paths (this can be adjusted for individual imaging needs).</li>
		<li>If the microscope has a motorized stage, ensure adequate time is allowed for each Z-stack acquisition. Set the time interval between acquisitions to equal scan time per position x number of positions to image (i.e. imaged tumor regions). 
		&#8203;NOTE: For simultaneous excitation of the green and red fluorophores, utilize a dual-line laser line-scanning program, with simultaneous 488 nm and 633 nm excitation. The wavelength of laser excitation selected will vary according to individual fluorescent proteins expressed.</li>
		<li>Maintain uniform laser power and confocal pinhole settings between the imaged tumor regions. Utilize the lowest laser power setting needed to clearly demarcate the tumor cell bodies and processes to limit phototoxicity. Specific imaging parameter units (i.e. power and confocal pinhole settings) will vary according to microscope and laser source specifications.</li>
		<li>Compensate for potential media evaporation by adding 2 - 3 &#34;buffer&#34; Z-stack steps in the focal planes advancing towards the objective. This effectively prevents the tissue from leaving the range of Z-stack acquisitions in the vertical plane.</li>
	</ol>
	</li>
</ol>
7. Image Post-Processing and Tumor Cell Tracking
NOTE: Many confocal imaging systems are equipped with proprietary image-processing software. The processing steps discussed below comprise a general protocol, which can be performed across software platforms. Specific instructions will be given for the open-source platforms, NIH ImageJ and MTrackJ15.
<ol>
	<li>Open a Z-stack file. In ImageJ, click &#34;Image&#8594;Stacks&#8594;Z Project.&#34; Chose the first and last Z-stack to include, and chose &#34;Max Intensity&#34; as the projection type. The result is a rendering called a maximum intensity projection (MIP). Create an MIP from each set of Z-stack images captured at each region imaged.</li>
	<li>Concatenate the MIPs from each region to create a time series. Click &#34;Image&#8594;Stacks&#8594;Images to Stack.&#34;</li>
	<li>Manually identify the location of the cell body &#34;centroid&#34; by selecting the visually approximated center point of the tumor cell body. This is accomplished by clicking on the cell body using the &#34;add&#34; track functionality of MTrackJ (an open-source plugin-in for NIH ImageJ).</li>
	<li>Click to demarcate the cell body location in each frame of the series of images. This creates a unique &#34;track&#34; for each cell. Sequentially, mark the cell body locations of the next cell. Repeat this process until all cell migration paths are tracked.</li>
	<li>Once a population of cells is tracked in a given tumor micro region, export all cell track coordinates using the &#34;measure&#34; function of MTrackJ. Save the file as an .xls format so the raw data can be analyzed using spreadsheet or user-generated software.</li>
	<li>Use the coordinates recorded for each point along a cell&#39;s migration track, to perform quantitative analyses including derivation of migration speed, directionality, and other migration metrics, as described in Parker et al16. 
	NOTE: All calculated distances and speeds are under-estimates of actual values. This is inherent in the transformation of three-dimensional images (and migration paths) to two-dimensional data through generation of maximum intensity projections.</li>
</ol>

<ol>
	<li>Beadle, 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=The+role+of+myosin+II+in+glioma+invasion+of+the+brain.">The role of myosin II in glioma invasion of the brain.</a> Mol Biol Cell. 19, 3357-3368 (2008).</li><li>Farin, 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=Transplanted+glioma+cells+migrate+and+proliferate+on+host+brain+vasculature:+a+dynamic+analysis.">Transplanted glioma cells migrate and proliferate on host brain vasculature: a dynamic analysis.</a> Glia. 53, 799-808 (2006).</li><li>Panopoulos, A., Howell, M., Fotedar, R., Margolis, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glioblastoma+motility+occurs+in+the+absence+of+actin+polymer.">Glioblastoma motility occurs in the absence of actin polymer.</a> Mol Biol Cell. 22, 2212-2220 (2011).</li><li>Ivkovic, 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=Direct+inhibition+of+myosin+II+effectively+blocks+glioma+invasion+in+the+presence+of+multiple+motogens.">Direct inhibition of myosin II effectively blocks glioma invasion in the presence of multiple motogens.</a> Mol Biol Cell. 23, 533-542 (2012).</li><li>Assanah, 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=Glial+progenitors+in+adult+white+matter+are+driven+to+form+malignant+gliomas+by+platelet-derived+growth+factor-expressing+retroviruses.">Glial progenitors in adult white matter are driven to form malignant gliomas by platelet-derived growth factor-expressing retroviruses.</a> J Neurosci. 26, 6781-6790 (2006).</li><li>Chaichana, K. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preservation+of+glial+cytoarchitecture+from+ex+vivo+human+tumor+and+non-tumor+cerebral+cortical+explants:+A+human+model+to+study+neurological+diseases.">Preservation of glial cytoarchitecture from ex vivo human tumor and non-tumor cerebral cortical explants: A human model to study neurological diseases.</a> J Neurosci Methods. 164, 261-270 (2007).</li><li>Grube, 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=Overexpression+of+fatty+acid+synthase+in+human+gliomas+correlates+with+the+WHO+tumor+grade+and+inhibition+with+Orlistat+reduces+cell+viability+and+triggers+apoptosis.">Overexpression of fatty acid synthase in human gliomas correlates with the WHO tumor grade and inhibition with Orlistat reduces cell viability and triggers apoptosis.</a> J Neurooncol. 118, 277-287 (2014).</li><li>Hovinga, K. 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=Inhibition+of+notch+signaling+in+glioblastoma+targets+cancer+stem+cells+via+an+endothelial+cell+intermediate.">Inhibition of notch signaling in glioblastoma targets cancer stem cells via an endothelial cell intermediate.</a> Stem Cells. 28, 1019-1029 (2010).</li><li>Merz, F., 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=Organotypic+slice+cultures+of+human+glioblastoma+reveal+different+susceptibilities+to+treatments.">Organotypic slice cultures of human glioblastoma reveal different susceptibilities to treatments.</a> Neurooncol. 15, 670-681 (2013).</li><li>Xu, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vorinostat+modulates+cell+cycle+regulatory+proteins+in+glioma+cells+and+human+glioma+slice+cultures.">Vorinostat modulates cell cycle regulatory proteins in glioma cells and human glioma slice cultures.</a> J Neurooncol. 105, 241-251 (2011).</li><li>Verhaak, R. G., 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=Integrated+genomic+analysis+identifies+clinically+relevant+subtypes+of+glioblastoma+characterized+by+abnormalities.">Integrated genomic analysis identifies clinically relevant subtypes of glioblastoma characterized by abnormalities.</a> in PDGFRA, IDH1, EGFR, and NF1. Cancer cell. 17, 98-110 (2010).</li><li>Gill, B. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MRI-localized+biopsies+reveal+subtype-specific+differences+in+molecular+and+cellular+composition+at+the+margins+of+glioblastoma.">MRI-localized biopsies reveal subtype-specific differences in molecular and cellular composition at the margins of glioblastoma.</a> Proc Natl Acad Sci USA. 111, 12550-12555 (2014).</li><li>Snuderl, 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=Mosaic+amplification+of+multiple+receptor+tyrosine+kinase+genes+in+glioblastoma.">Mosaic amplification of multiple receptor tyrosine kinase genes in glioblastoma.</a> Cancer cell. 20, 810-817 (2011).</li><li>Kakita, A., Goldman, 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=Patterns+and+dynamics+of+SVZ+cell+migration+in+the+postnatal+forebrain:+monitoring+living+progenitors+in+slice+preparations.">Patterns and dynamics of SVZ cell migration in the postnatal forebrain: monitoring living progenitors in slice preparations.</a> Neuron. 23, 461-472 (1999).</li><li>Meijering, E., Dzyubachyk, O., Smal, I., van Cappellen, W. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tracking+in+cell+and+developmental+biology.">Tracking in cell and developmental biology.</a> Sem Cell Dev Biol. 20, 894-902 (2009).</li><li>Parker, J. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gefitinib+selectively+inhibits+tumor+cell+migration+in+EGFR-amplified+human+glioblastoma.">Gefitinib selectively inhibits tumor cell migration in EGFR-amplified human glioblastoma.</a> Neurooncol. 15, 1048-1057 (2013).</li><li>Brat, D. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pseudopalisades+in+glioblastoma+are+hypoxic,+express+extracellular+matrix+proteases,+and+are+formed+by+an+actively+migrating+cell+population.">Pseudopalisades in glioblastoma are hypoxic, express extracellular matrix proteases, and are formed by an actively migrating cell population.</a> Cancer Res. 64, 920-927 (2004).</li><li>Shweiki, D., Itin, A., Soffer, D., Keshet, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vascular+endothelial+growth+factor+induced+by+hypoxia+may+mediate+hypoxia-initiated+angiogenesis.">Vascular endothelial growth factor induced by hypoxia may mediate hypoxia-initiated angiogenesis.</a> Nature. 359, 843-845 (1992).</li><li>Shamir, E. R., Ewald, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+organotypic+culture:+experimental+models+of+mammalian+biology+and+disease.">Three-dimensional organotypic culture: experimental models of mammalian biology and disease.</a> Nat Rev Mol Cell Biol. 15, 647-664 (2014).</li><li>Charles, N. A., Holland, E. C., Gilbertson, R., Glass, R., Kettenmann, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+brain+tumor+microenvironment.">The brain tumor microenvironment.</a> Glia. 60, 502-514 (2012).</li><li>Di Cristofori, 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=The+vacuolar+H++ATPase+is+a+novel+therapeutic+target+for+glioblastoma.">The vacuolar H+ ATPase is a novel therapeutic target for glioblastoma.</a> Oncotarget. 6, 17514-17513 (2015).</li><li>Vaira, V., 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=Preclinical+model+of+organotypic+culture+for+pharmacodynamic+profiling+of+human+tumors.">Preclinical model of organotypic culture for pharmacodynamic profiling of human tumors.</a> Proc Natl Acad Sci USA. , 8352-8356 (2010).</li><li>Gerlach, M. 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=Slice+cultures+from+head+and+neck+squamous+cell+carcinoma:+a+novel+test+system+for+drug+susceptibility+and+mechanisms+of+resistance.">Slice cultures from head and neck squamous cell carcinoma: a novel test system for drug susceptibility and mechanisms of resistance.</a> Br J Cancer. 110, 479-488 (2014).</li><li>Holliday, D. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+practicalities+of+using+tissue+slices+as+preclinical+organotypic+breast+cancer+models.">The practicalities of using tissue slices as preclinical organotypic breast cancer models.</a> J Clin Pathol. 66, 253-255 (2013).</li><li>Maund, S. L., Nolley, R., Peehl, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimization+and+comprehensive+characterization+of+a+faithful+tissue+culture+model+of+the+benign+and+malignant+human+prostate.">Optimization and comprehensive characterization of a faithful tissue culture model of the benign and malignant human prostate.</a> Lab Invest. 94, 208-221 (2014).</li></ol>

The authors have nothing to disclose.

Organotypic slice cultures from human cancer tissue provide an attractive and underutilized platform for pre-clinical translational experimentation. Understanding of population-level behaviors of tumor cells with regards to migration, proliferation, and cell death in the native tumor microenvironment is lacking. Critically, studying tumor response to therapy in a dynamic, time-resolved fashion at the level of cell behavior may shed light on novel mechanisms of treatment resistance. Human tumor slice cultures provide a li...

The laboratory study of glioblastoma (GBM), is hindered by a lack of models that faithfully recapitulate the requisite pathologic characteristics of the human disease, namely tumor cell migration and invasion. Comparative studies of 2D and 3D in vitro invasion assays as well as 3D rodent slice culture models have uncovered mechanistically disparate cellular migration programs in these two contexts, potentially limiting the translatability of findings from 2D systems to the human disease1,2,3. The organotypic tumor slice culture and imaging paradigm described here allows for the study of tumor cell migration within slices of ex vivo human tumor tissue obtained from surgical resection. Thus, slice cultures of surgically resected tumor tissue in conjunction with time-lapse confocal microscopy provide a platform to study tumor cell migration in the native microenvironment without tissue dissolution or culture passaging.
There is extensive literature employing rodent brain slice culture models of GBM generated from human tumor xenografts, retroviral-induced tumors, and cellular overlays to study tumor invasion1,2,3,4,5. Recently, several groups have described the generation of organotypic slice cultures directly from human GBM tissue6,7,8,9,10. However, there is marked variation among published protocols with regards to slicing technique and culture media. Further, the use of organotypic slice cultures has focused on static experimental endpoints that have included changes in cell signaling, proliferation, and death. The protocol described herein expands upon prior slice culture paradigms by incorporating time-resolved observation of dynamic tumor cell behaviors through time-lapse laser scanning confocal microscopy. Recent discovery of inter11 and intratumoral12,13 genetic variation in human GBM underlines the importance of linking this heterogeneity with tumor cell behaviors and its implications on tumor response to therapy. Here, we report a streamlined and reproducible protocol for use of direct slice cultures from a human cancer tissue to visualize tumor cell migration in near real-time.

<table fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>DMEM High Glucose&#160;</td>
			<td>Invitrogen (Gibco)</td>
			<td>11960-044</td>
			<td></td>
		</tr>
		<tr>
			<td>Neurobasal-A Medium, minus phenol red</td>
			<td>Invitrogen (Gibco)</td>
			<td>12349-015</td>
			<td></td>
		</tr>
		<tr>
			<td>B-27 Supplement (50X), serum free</td>
			<td>Invitrogen (Gibco)</td>
			<td>17504-044</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin (10,000 U/mL)</td>
			<td>Invitrogen (Gibco)</td>
			<td>15140-122</td>
			<td></td>
		</tr>
		<tr>
			<td>GlutaMAX Supplement</td>
			<td>Invitrogen (Gibco)</td>
			<td>35050-061</td>
			<td></td>
		</tr>
		<tr>
			<td>L-Glutamine (200 mM)</td>
			<td>Invitrogen (Gibco)</td>
			<td>25030-081</td>
			<td></td>
		</tr>
		<tr>
			<td>HEPES (1 M)</td>
			<td>Invitrogen (Gibco)</td>
			<td>15630-080</td>
			<td></td>
		</tr>
		<tr>
			<td>Nystatin Suspension</td>
			<td>Sigma-Aldrich</td>
			<td>N1638-20ML</td>
			<td>10,000 unit/mL in DPBS, aseptically processed, BioReagent, suitable for cell culture</td>
		</tr>
		<tr>
			<td>UltraPure Low Melting Point Agarose</td>
			<td>Invitrogen (Gibco)</td>
			<td>16520-050</td>
			<td>Melts at 65.5 C, Remains fluid at 37 C, and sets rapidly below 25 C.</td>
		</tr>
		<tr>
			<td>Isolectin GS-IB4 from Griffonia simplicifolia, Alexa Fluor 647 Conjugate</td>
			<td>Thermo Fisher (Molecular Probes)</td>
			<td>I32450</td>
			<td>Used in media to label Microglia/Macrophages</td>
		</tr>
		<tr>
			<td>pRetroX-IRES-ZsGreen1 Vector</td>
			<td>Clonetech</td>
			<td>632520</td>
			<td></td>
		</tr>
		<tr>
			<td>Retro-X Concentrator&#160;</td>
			<td>Clonetech</td>
			<td>31455</td>
			<td>Binding resin for non-ultracentrifugation concentration of viral supernatants</td>
		</tr>
		<tr>
			<td>pVSG-G Vector</td>
			<td>Clonetech</td>
			<td>631530</td>
			<td>part of the Retro-X Universal Retroviral Expression System</td>
		</tr>
		<tr>
			<td>GP2-293 Viral packaging cells</td>
			<td>Clonetech</td>
			<td>631530</td>
			<td>part of the Retro-X Universal Retroviral Expression System</td>
		</tr>
		<tr>
			<td>Cyanoacrylate Glue (Super Glue)</td>
			<td>Sigma-Aldrich</td>
			<td>Z105899</td>
			<td>Medium-viscosity</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Peel-A-Way Embedding Mold (Square - S22)</td>
			<td>Polysciences, Inc.</td>
			<td>18646A-1</td>
			<td>Molds for tumor sample embedding</td>
		</tr>
		<tr>
			<td>Stainless Steel Micro Spatulas</td>
			<td>Fisher Scientific</td>
			<td>S50823</td>
			<td>Bend instrument 45 degrees at the neck of the spoon blade</td>
		</tr>
		<tr>
			<td>Curved Fisherbrand Dissecting Fine-Pointed Forceps</td>
			<td>Fisher Scientific&#160;</td>
			<td>08-875</td>
			<td></td>
		</tr>
		<tr>
			<td>Single Edge Razor Blade (American Safety Razors)</td>
			<td>Fisher Scientific</td>
			<td>17-989-001</td>
			<td>Blade edge is 0.009&#34; thick. Crimped blunt-edge cover is removed before loading onto vibratome.</td>
		</tr>
		<tr>
			<td>Leica VT1000 S Vibratome</td>
			<td>Leica Biosystems</td>
			<td>VT1000 S</td>
			<td></td>
		</tr>
		<tr>
			<td>Hydrophilic PTFE cell culture insert&#160;</td>
			<td>EMD Millipore</td>
			<td>PICM0RG50</td>
			<td>30 mm, hydrophilic PTFE, 0.4 &#181;m pore size</td>
		</tr>
		<tr>
			<td>35 mm Glass Bottom Dishes&#160;</td>
			<td>MatTek</td>
			<td>P35G-1.5-20-C Sleeve</td>
			<td>20mm glass diameter. Coverslip glass thickness 1.5</td>
		</tr>
		<tr>
			<td>LSM 510 Confocal Micoscope</td>
			<td>Zeiss</td>
			<td>LSM 510</td>
			<td>10x Air Objective (c-Apochromat NA 0.45)</td>
		</tr>
		<tr>
			<td>PECON Stagetop Incubator</td>
			<td>PeCON Germany</td>
			<td>(Discontinued)</td>
			<td>Incubator PM 2000 RBT is a comprable product designed for use with Zeiss Microscopes.</td>
		</tr>
	</tbody>
</table>

a human glioblastoma organotypic slice culture model for study of tumor cell migration and patient-specific effects of anti-invasive drugs

Glioblastoma (GBM) continues to carry an extremely poor clinical prognosis despite surgical, chemotherapeutic, and radiation therapy. Progressive tumor invasion into surrounding brain parenchyma represents an enduring therapeutic challenge. To develop anti-migration therapies for GBM, model systems that provide a physiologically relevant background for controlled experimentation are essential. Here, we present a protocol for generating slice cultures from human GBM tissue obtained during surgical resection. These cultures allow for ex vivo experimentation without passaging through animal xenografts or single cell cultures. Further, we describe the use of time-lapse laser scanning confocal microscopy in conjunction with cell tracking to quantitatively study the migratory behavior of tumor cells and associated response to therapeutics. Slices are reproducibly generated within 90 min of surgical tissue acquisition. Retrovirally-mediated fluorescent cell labeling, confocal imaging, and tumor cell migration analyses are subsequently completed within two weeks of culture. We have successfully used these slice cultures to uncover genetic factors associated with increased migratory behavior in human GBM. Further, we have validated the model&#39;s ability to detect patient-specific variation in response to anti-migration therapies. Moving forward, human GBM slice cultures are an attractive platform for rapid ex vivo assessment of tumor sensitivity to therapeutic agents, in order to advance personalized neuro-oncologic therapy.

Our group has successfully generated slice cultures from over 50 patients undergoing initial GBM resection. This slice generation, culture, retroviral-labeling, imaging, and migration analysis protocol has been streamlined into a reproducible workflow (Figure 1). Critically, these organotypic GBM slices demonstrate concordance with originating tumor tissue throughout culture, including maintenance of pathologic hallmarks and microglia up to 15 days in culture (Fig...

Watch this Scientific Journal Video about A Human Glioblastoma Organotypic Slice Culture Model for Study of Tumor Cell Migration and Patient-specific Effects of Anti-Invasive Drugs at JoVE.com

A Human Glioblastoma Organotypic Slice Culture Model for Study of Tumor Cell Migration and Patient-specific Effects of Anti-Invasive Drugs

Current ex vivo models of glioblastoma (GBM) are not optimized for physiologically relevant study of human tumor invasion. Here, we present a protocol for generation and maintenance of organotypic slice cultures from fresh human GBM tissue. A description of time-lapse microscopy and quantitative cell migration analysis techniques is provided.

Glioblastoma (GBM) continues to carry an extremely poor clinical prognosis despite surgical, chemotherapeutic, and radiation therapy. Progressive tumor ...

a-human-glioblastoma-organotypic-slice-culture-model-for-study-tumor

Research

JoVE Journal

Medicine

12.7K Views.  Stanford University Hospital, Stanford University School of Medicine. Current ex vivo models of glioblastoma (GBM) are not optimized for physiologically relevant study of human tumor invasion. Here, we present a protocol for generation and maintenance of organotypic slice cultures from fresh human GBM tissue. A description of time-lapse microscopy and quantitative cell migration analysis techniques is provided.

Video: A Human Glioblastoma Organotypic Slice Culture Model for Study of Tumor Cell Migration and Patient-specific Effects of Anti-Invasive Drugs

Multi-photon Imaging of Tumor Cell Invasion in an Orthotopic Mouse Model of Oral Squamous Cell Carcinoma

Loco-regional invasion of head and neck cancer is linked to metastatic risk and presents a difficult challenge in designing and implementing patient management strategies. Orthotopic mouse models of oral cancer have been developed to facilitate the study of factors that impact invasion and serve as model system for evaluating anti-tumor therapeutics. In these systems, visualization of disseminated tumor cells within oral cavity tissues has typically been conducted by either conventional histology or with in vivo bioluminescent methods. A primary drawback of these techniques is the inherent inability to accurately visualize and quantify early tumor cell invasion arising from the primary site in three dimensions. Here we describe a protocol that combines an established model for squamous cell carcinoma of the tongue (SCOT) with two-photon imaging to allow multi-vectorial visualization of lingual tumor spread. The OSC-19 head and neck tumor cell line was stably engineered to express the F-actin binding peptide LifeAct fused to the mCherry fluorescent protein (LifeAct-mCherry). Fox1nu/nu mice injected with these cells reliably form tumors that allow the tongue to be visualized by ex-vivo application of two-photon microscopy. This technique allows for the orthotopic visualization of the tumor mass and locally invading cells in excised tongues without disruption of the regional tumor microenvironment. In addition, this system allows for the quantification of tumor cell invasion by calculating distances that invaded cells move from the primary tumor site. Overall this procedure provides an enhanced model system for analyzing factors that contribute to SCOT invasion and therapeutic treatments tailored to prevent local invasion and distant metastatic spread. This method also has the potential to be ultimately combined with other imaging modalities in an in vivo setting.

A comprehensive overview of the techniques involved in generating a mouse model of oral cancer and quantitative monitoring of tumor invasion within the tongue through multi-photon microscopy of labeled cells is presented. This system can serve as a useful platform for the molecular assessment and drug efficacy of anti-invasive compounds.

Loco-regional invasion of head and neck cancer is linked to metastatic risk and presents a difficult challenge in designing and implementing patient ...

Human Neuroendocrine Tumor Cell Lines as a Three-Dimensional Model for the Study of Human Neuroendocrine Tumor Therapy

Neuroendocrine tumors (NETs) are rare tumors, with an incidence of two per 100,&#x200A;000 individuals per year, and they account for 0.5% of all human malignancies.1 Other than surgery for the minority of patients who present with localized disease, there is little or no survival benefit of systemic therapy. Therefore, there is a great need to better understand the biology of NETs, and in particular define new therapeutic targets for patients with nonresectable or metastatic neuroendocrine tumors. 3D cell culture is becoming a popular method for drug screening due to its relevance in modeling the in vivo tumor tissue organization and microenvironment.2,3 The 3D multicellular spheroids could provide valuable information in a more timely and less expensive manner than directly proceeding from 2D cell culture experiments to animal (murine) models.
To facilitate the discovery of new therapeutics for NET patients, we have developed an in vitro 3D multicellular spheroids model using the human NET cell lines. The NET cells are plated in a non-adhesive agarose-coated 24-well plate and incubated under physiological conditions (5% CO2, 37 &deg;C) with a very slow agitation for 16-24 hr after plating. The cells form multicellular spheroids starting on the 3rd or 4th day. The spheroids become more spherical by the 6th day, at which point the drug treatments are initiated. The efficacy of the drug treatments on the NET spheroids is monitored based on the morphology, shape and size of the spheroids with a phase-contrast light microscope. The size of the spheroids is estimated automatically using a custom-developed MATLAB program based on an active contour algorithm. Further, we demonstrate a simple method to process the HistoGel embedding on these 3D spheroids, allowing the use of standard histological and immunohistochemical techniques. 
This is the first report on generating 3D spheroids using NET cell lines to examine the effect of therapeutic drugs. We have also performed histology on these 3D spheroids, and displayed an example of a single drug's effect on growth and proliferation of the NET spheroids. Our results support that the NET spheroids are valuable for further studies of NET biology and drug development.

We present a simple agarose overlay platform to grow 3D multicellular spheroids using neuroendocrine cancer cell lines. This method provides a very convenient way to examine the effect of therapeutic drugs on the neuroendocrine tumor cells. It could also help us establish human neuroendocrine tumor spheroids for cancer therapy.

Neuroendocrine tumors (NETs) are rare tumors, with an incidence of two per 100,&#x200A;000 individuals per year, and they account for 0.5% of all human ...

Processing of Human Reduction Mammoplasty and Mastectomy Tissues for Cell Culture

Experimental examination of normal human mammary epithelial cell (HMEC) behavior, and how normal cells acquire abnormal properties, can be facilitated by in vitro culture systems that more accurately model in vivo biology. The use of human derived material for studying cellular differentiation, aging, senescence, and immortalization is particularly advantageous given the many significant molecular differences in these properties between human and commonly utilized rodent cells1-2. Mammary cells present a convenient model system because large quantities of normal and abnormal tissues are available due to the frequency of reduction mammoplasty and mastectomy surgeries.
The mammary gland consists of a complex admixture of many distinct cell types, e.g., epithelial, adipose, mesenchymal, endothelial. The epithelial cells are responsible for the differentiated mammary function of lactation, and are also the origin of the vast majority of human breast cancers. We have developed methods to process mammary gland surgical discard tissues into pure epithelial components as well as mesenchymal cells3. The processed material can be stored frozen indefinitely, or initiated into primary culture. Surgical discard material is transported to the laboratory and manually dissected to enrich for epithelial containing tissue. Subsequent digestion of the dissected tissue using collagenase and hyaluronidase strips stromal material from the epithelia at the basement membrane. The resulting small pieces of the epithelial tree (organoids) can be separated from the digested stroma by sequential filtration on membranes of fixed pore size. Depending upon pore size, fractions can be obtained consisting of larger ductal/alveolar pieces, smaller alveolar clusters, or stromal cells. We have observed superior growth when cultures are initiated as organoids rather than as dissociated single cells. Placement of organoids in culture using low-stress inducing media supports long-term growth of normal HMEC with markers of multiple lineage types (myoepithelial, luminal, progenitor)4-5. Sufficient numbers of cells can be obtained from one individual's tissue to allow extensive experimental examination using standardized cell batches, as well as interrogation using high throughput modalities.
Cultured HMEC have been employed in a wide variety of studies examining the normal processes governing growth, differentiation, aging, and senescence, and how these normal processes are altered during immortal and malignant transformation4-15,16. The effects of growth in the presence of extracellular matrix material, other cell types, and/or 3D culture can be compared with growth on plastic5,15. Cultured HMEC, starting with normal cells, provide an experimentally tractable system to examine factors that may propel or prevent human aging and carcinogenesis.

A method to process human mammary surgical discard material is described. Processed tissue, in the form of organoids, can be stored frozen indefinitely or placed in culture for long-term growth. This method enables experimental examination of normal human epithelial cell biology, and the effects of exogenous perturbations.

Experimental  examination of normal human mammary epithelial cell (HMEC) behavior, and how  normal cells acquire abnormal properties, can be facilitated ...

Patient Derived Cell Culture and Isolation of CD133+ Putative Cancer Stem Cells from Melanoma

Despite improved treatments options for melanoma available today, patients with advanced malignant melanoma still have a poor prognosis for progression-free and overall survival. Therefore, translational research needs to provide further molecular evidence to improve targeted therapies for malignant melanomas. In the past, oncogenic mechanisms related to melanoma were extensively studied in established cell lines. On the way to more personalized treatment regimens based on individual genetic profiles, we propose to use patient-derived cell lines instead of generic cell lines. Together with high quality clinical data, especially on patient follow-up, these cells will be instrumental to better understand the molecular mechanisms behind melanoma progression.
Here, we report the establishment of primary melanoma cultures from dissected fresh tumor tissue. This procedure includes mincing and dissociation of the tissue into single cells, removal of contaminations with erythrocytes and fibroblasts as well as primary culture and reliable verification of the cells' melanoma origin.
Recent reports revealed that melanomas, like the majority of tumors, harbor a small subpopulation of cancer stem cells (CSCs), which seem to exclusively fuel tumor initiation and progression towards the metastatic state. One of the key markers for CSC identification and isolation in melanoma is CD133. To isolate CD133+ CSCs from primary melanoma cultures, we have modified and optimized the Magnetic-Activated Cell Sorting (MACS) procedure from Miltenyi resulting in high sorting purity and viability of CD133+ CSCs and CD133- bulk, which can be cultivated and functionally analyzed thereafter.

Patient Derived Cell Culture and Isolation of CD133+ Putative Cancer Stem Cells from Melanoma

This article describes the preparation of freshly obtained melanoma tissue into primary cell cultures, and how to remove contaminations of erythrocytes and fibroblasts from the tumor cells. Finally, we describe how CD133+ putative melanoma stem cells are sorted from the CD133- bulk using Magnetic Activated Cell Sorting (MACS).

Despite improved treatments options for melanoma available today, patients with advanced malignant melanoma still have a poor prognosis for ...

A Three-dimensional Tissue Culture Model to Study Primary Human Bone Marrow and its Malignancies

Tissue culture has been an invaluable tool to study many aspects of cell function, from normal development to disease. Conventional cell culture methods rely on the ability of cells either to attach to a solid substratum of a tissue culture dish or to grow in suspension in liquid medium. Multiple immortal cell lines have been created and grown using such approaches, however, these methods frequently fail when primary cells need to be grown ex vivo. Such failure has been attributed to the absence of the appropriate extracellular matrix components of the tissue microenvironment from the standard systems where tissue culture plastic is used as a surface for cell growth. Extracellular matrix is an integral component of the tissue microenvironment and its presence is crucial for the maintenance of physiological functions such as cell polarization, survival, and proliferation. Here we present a 3-dimensional tissue culture method where primary bone marrow cells are grown in extracellular matrix formulated to recapitulate the microenvironment of the human bone (rBM system). Embedded in the extracellular matrix, cells are supplied with nutrients through the medium supplemented with human plasma, thus providing a comprehensive system where cell survival and proliferation can be sustained for up to 30 days while maintaining the cellular composition of the primary tissue. Using the rBM system we have successfully grown primary bone marrow cells from normal donors and patients with amyloidosis, and various hematological malignancies. The rBM system allows for direct, in-matrix real time visualization of the cell behavior and evaluation of preclinical efficacy of novel therapeutics. Moreover, cells can be isolated from the rBM and subsequently used for in vivo transplantation, cell sorting, flow cytometry, and nucleic acid and protein analysis. Taken together, the rBM method provides a reliable system for the growth of primary bone marrow cells under physiological conditions.

In standard culture methods cells are taken out of their physiological environment and grown on the plastic surface of a dish. To study the behavior of primary human bone marrow cells we created a 3-D culture system where cells are grown under conditions recapitulating the native microenvironment of the tissue.

Tissue culture has been an invaluable tool to study many aspects of cell function, from normal development to disease. Conventional cell culture methods ...

Human Dupuytren's Ex Vivo Culture for the Study of Myofibroblasts and Extracellular Matrix Interactions

Organ fibrosis or &#8220;scarring&#8221; is known to account for a high death toll due to the extensive amount of disorders and organs affected (from cirrhosis to cardiovascular diseases). There is no effective treatment and the in vitro tools available do not mimic the in vivo situation rendering the progress of the out of control wound healing process still enigmatic.
To date, 2D and 3D cultures of fibroblasts derived from DD patients are the main experimental models available. Primary cell cultures have many limitations; the fibroblasts derived from DD are altered by the culture conditions, lack cellular context and interactions, which are crucial for the development of fibrosis and weakly represent the derived tissue. Real-time PCR analysis of fibroblasts derived from control and DD samples show that little difference is detectable. 3D cultures of fibroblasts include addition of extracellular matrix that alters the native conditions of these cells. 
As a way to characterize the fibrotic, proliferative properties of these resection specimens we have developed a 3D culture system, using intact human resections of the nodule part of the cord. The system is based on transwell plates with an attached nitrocellulose membrane that allows contact of the tissue with the medium but not with the plastic, thus, preventing the alteration of the tissue. No collagen gel or other extracellular matrix protein substrate is required. The tissue resection specimens maintain their viability and proliferative properties for 7 days. This is the first &#8220;organ&#8221; culture system that allows human resection specimens from DD patients to be grown ex vivo and functionally tested, recapitulating the in vivo situation.

Human Dupuytren's Ex Vivo Culture for the Study of Myofibroblasts and Extracellular Matrix Interactions

Dupuytren&#8217;s disease (DD) is a fibroproliferative disease of the palm of the hand. Here, we present a protocol to culture resection specimens from DD in a three-dimensional (3D) culture system. Such short-term culture system allows preservation of the 3D structure and molecular properties of the fibrotic tissue.

Organ fibrosis or &#8220;scarring&#8221; is known to account for a high death toll due to the extensive amount of disorders and organs affected (from ...

Isolation and Culture Expansion of Tumor-specific Endothelial Cells

Freshly isolated tumor-specific endothelial cells (TEC) can be used to explore molecular mechanisms of tumor angiogenesis and serve as an in vitro model for developing new angiogenesis inhibitors for cancer. However, long-term in vitro expansion of murine endothelial cells (EC) is challenging due to phenotypic drift in culture (endothelial-to-mesenchymal transition) and contamination with non-EC. This is especially true for TEC which are readily outcompeted by co-purified fibroblasts or tumor cells in culture. Here, a high fidelity isolation method that takes advantage of immunomagnetic enrichment coupled with colony selection and in vitro expansion is described. This approach generates pure EC fractions that are entirely free of contaminating stromal or tumor cells. It is also shown that lineage-traced Cdh5cre:ZsGreenl/s/l reporter mice, used with the protocol described herein, are a valuable tool to verify cell purity as the isolated EC colonies from these mice show durable and brilliant ZsGreen fluorescence in culture.

We report a reliable method to isolate and culture primary tumor-specific endothelial cells from genetically engineered mouse models.

Freshly isolated tumor-specific endothelial cells (TEC) can be used to explore molecular mechanisms of tumor angiogenesis and serve as an in vitro model ...

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

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

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

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

Assessing Specificity of Anticancer Drugs In Vitro

A procedure for assessing specificity of anticancer drugs in vitro using cultures containing both tumor and non-tumor cells is demonstrated. The key element is the quantitative determination of a tumor-specific genetic alteration in relation to a universal sequence using a dual-probe digital PCR assay and the subsequent calculation of the proportion of tumor cells. The assay is carried out on a culture containing tumor cells of an established line and spiked-in non-tumor cells. The mixed culture is treated with a test drug at various concentrations. After the treatment, DNA is prepared directly from the survived adhesive cells in wells of 96-well plates using a simple and inexpensive method, and subjected to a dual-probe digital PCR assay for measuring a tumor-specific genetic alteration and a reference universal sequence. In the present demonstration, a heterozygous deletion of the NF1 gene is used as the tumor-specific genetic alteration and a RPP30 gene as the reference gene. Using the ratio NF1/RPP30, the proportion of tumor cells was calculated. Since the dose-dependent change of the proportion of tumor cells provides an in vitro indication for specificity of the drug, this genetic and cell-based in vitro assay will likely have application potential in drug discovery. Furthermore, for personalized cancer-care, this genetic- and cell-based tool may contribute to optimizing adjuvant chemotherapy by means of testing efficacy and specificity of candidate drugs using primary cultures of individual tumors.

Assessing Specificity of Anticancer Drugs In Vitro

The goal of this protocol is to assess specificity of anticancer drugs in vitro using mixed cultures containing both tumor and non-tumor cells.

A procedure for assessing specificity of anticancer drugs in vitro using cultures containing both tumor and non-tumor cells is demonstrated. The key ...

A Cell Culture Model of Resistance Arteries

The myoendothelial junction (MEJ), a unique signaling microdomain in small diameter resistance arteries, exhibits localization of specific proteins and signaling processes that can control vascular tone and blood pressure. As it is a projection from either the endothelial or smooth muscle cell, and due to its small size (on average, an area of ~1 &#181;m2), the MEJ is difficult to study in isolation. However, we have developed a cell culture model called the vascular cell co-culture (VCCC) that allows for in vitro MEJ formation, endothelial cell polarization, and dissection of signaling proteins and processes in the vascular wall of resistance arteries. The VCCC has a multitude of applications and can be adapted to suit different cell types. The model consists of two cell types grown on opposite sides of a filter with 0.4 &#181;m pores in which the in vitro MEJs can form. Here we describe how to create the VCCC via plating of cells and isolation of endothelial, MEJ, and smooth muscle fractions, which can then be used for protein isolation or activity assays. The filter with intact cell layers can be fixed, embedded, and sectioned for immunofluorescent analysis. Importantly, many of the discoveries from this model have been confirmed using intact resistance arteries, underscoring its physiological relevance.

A cell culture model of resistance arteries is described, allowing for the dissection of signaling pathways in endothelium, smooth muscle, or between endothelium and smooth muscle (the myoendothelial junction). The selective application of agonists or protein isolation, electron microscopy, or immunofluorescence can be utilized using this cell culture model.

The myoendothelial junction (MEJ), a unique signaling microdomain in small diameter resistance arteries, exhibits localization of specific proteins and ...