Name: modeling chemotherapy resistant leukemia in vitro
Uploaded: 2016-02-09T14:00:00
Description: Watch this Scientific Journal Video about Modeling Chemotherapy Resistant Leukemia In Vitro at JoVE.com

Supported by National Institutes of Health (NHLBI) R01 HL056888 (LFG), National Cancer Institute (NCI) RO1 CA134573NIH (LFG), P30 GM103488 (LFG), WV CTR-IDEA NIH 1U54 GM104942, the Alexander B. Osborn Hematopoietic Malignancy and Transplantation Program, and the WV Research Trust Fund. We are grateful for the support of Dr. Kathy Brundage and the West Virginia University Flow Cytometry Core Facility, supported by NIH S10-OD016165 and the Institutional Development Award (IDeA) from the NIH Institute of General Medical Sciences of the National Institutes of Health (CoBRE P30GM103488 and INBRE P20GM103434).

1. Advanced Preparation
<ol>
	<li>Preparing dextran G10 particles.
	<ol>
		<li>Prepare G10 slurry by adding 50 ml 1x PBS to 10 g G10 particles. Mix by inversion and allow G10 to settle out of phosphate buffered saline (PBS) at 4 &#176;C O/N.</li>
		<li>The day of G10 column separation, aspirate PBS from settled G10 particles and add 50 ml fresh PBS. Mix by inversion. Repeat twice, adding 50 ml fresh PBS to settled G10 particles and store at 4&#160;&#176;C until ready to use.</li>
	</ol>
	</li>
	<li>Culturing BMSC and O...

<ol>
	<li>Ayala, F., Dewar, R., Kieran, M., Kalluri, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Contribution+of+bone+microenvironment+to+leukemogenesis+and+leukemia+progression.">Contribution of bone microenvironment to leukemogenesis and leukemia progression.</a> Leukemia. 23 (12), 2233-2241 (2009).</li><li>Coustan-Smith, E., Sancho, 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=Clinical+importance+of+minimal+residual+disease+in+childhood+acute+lymphoblastic+leukemia.">Clinical importance of minimal residual disease in childhood acute lymphoblastic leukemia.</a> Blood. 96 (8), 2691-2696 (2000).</li><li>Gaynon, P. S., Qu, R. 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Minimal residual disease (MRD) which contributes to relapse of disease continues to be a major clinical challenge in the treatment of aggressive refractory ALL, as well as, a host of other hematological malignancies. The bone marrow microenvironment is the most common site of relapse in ALL3,8. As such, models that model the bone marrow microenvironment are vital tools to test hypotheses related to leukemic tumor cell survival and maintenance of MRD during chemotherapy exposure. While mouse models define the g...

The overall goal of the method described is to provide an efficient, cost-effective in vitro approach that supports investigation of the mechanisms that underlie bone marrow supported survival of leukemic cells during chemotherapy exposure. It is well documented that surviving residual tumor cells that persist after treatment contribute to relapse of disease that is often more aggressive than that at diagnosis and is often less effectively treated1-8. Models that include leukemic cells in isolation, such as those limited to culture of cells in media alone, for testing of therapeutic approaches do not factor in these critical signals, or the heterogeneity of disease that occurs in response to availability of niche derived cues in which tumor cell subpopulations with very specific interactions with niche cells derive enhanced protection. Standard 2D co-culture models that co-culture bone marrow derived stromal cells and leukemic cells have somewhat addressed the contribution of the marrow niche and have shown that interaction with bone marrow microenvironment cells increases their resistance to chemotherapy and alters their growth characteristics9-14. These models however often fail to recapitulate long term survival of tumor cells and do not accurately inform the outcomes associated with the most resistant leukemic cell populations that contribute to MRD. In vivo models remain critical and define the "gold standard" for investigation of innovative therapies prior to clinical trials but they are often challenged by the time and cost required to test hypotheses related to resistant tumors and relapse of disease. As such, development of more informative 2D models would be of benefit for pilot investigations to better inform the design of subsequent murine based pre-clinical design. 
The 2D in vitro model presented in this report lacks the complexity of the true in vivo microenvironment, but provides a cost effective and reproducible means to interrogate tumor interactions with the microenvironment that lends itself specifically to enrichment of the chemoresistant subpopulation of tumor cells. This distinction is valuable as evaluation of the entire population of tumor cells may mask the phenotype of a minor group of therapy resistant tumor cells that comprise the most important target. An additional advantage is the scalability of the model to fit the analysis of interest. Bulk cultures can be established for those analyses requiring significant recovery of tumor cells, while small scale co-cultures in multi-well plates can be utilized for PCR based analysis or microscopy based evaluations. 
Based on this need we developed an in vitro model to address the heterogeneity of disease that is characteristic of B-lineage acute lymphoblastic leukemia (ALL). We demonstrate that ALL cells, which share many characteristics in common with their healthy counterparts, localize to distinct compartments of BMSC or OB co-culture. Three populations of tumor cells are generated that have distinct phenotypes that are valuable for investigation of therapeutic response. Specifically, we demonstrate that (ALL) cells recovered from the "phase dim" (PD) population of co-culture are consistently refractory to therapy with survival that approximates tumor cells that have not been exposed to cytotoxic agents. These ALL cells, from either established cell lines or primary patient samples, migrate beneath adherent stromal cells or osteoblast layers but can be captured following trypsinization of cultures and separation of cell types by utilization of gel type 10 cross-linked dextran (G10) particle columns15. 
Here we present a setup of a 2D co-culture that can be employed to model interactions between bone marrow microenvironment stromal cells (BMSC/OB) and leukemic cells. Of particular importance is the observation that leukemic cells form three spatial subpopulations relative to the stromal cell monolayer and that the PD population represents a chemotherapy resistant tumor population due to its interaction with the BMSC or OB. Furthermore, we demonstrate how to effectively isolate the leukemic cell populations by G10 columns. Of note, we have found that isolation of these subpopulations allows for downstream analysis of the most resistant PD population to determine potential modes of resistance that are conferred to these cells due to their interaction with the bone marrow microenvironment stromal cells or osteoblasts. Techniques that we have utilized downstream of this co-culture and isolation model include flow cytometric evaluation, proteomic analysis and targeted protein expression evaluation as well as more recently developed laser ablation electrospray ionization (LAESI) and Seahorse analysis to evaluate metabolic profiles. Through use of this model in combination with the techniques above we have found that the PD population of leukemic cells has a chemotherapy resistant phenotype that is unique when compared to leukemic cells cultured in media alone or those recovered from the other subpopulations in the same co-culture. As such, this model lends itself to more rigorous evaluation to test strategies targeting the most chemotherapy resistant leukemic cells which derive their resistant phenotype through interaction with the bone marrow microenvironment.

<table border="0" cellpadding="0" cellspacing="0" width="734">
	<tbody>
		<tr height="60">
			<td height="60" style="height:60px;width:224px;">G10 sephadex beads</td>
			<td style="width:149px;">Sigma</td>
			<td style="width:119px;">G10120</td>
			<td style="width:243px;">Referred to in manuscript as gel type 10 cross-linked dextran particles</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:224px;">10 ml sterile syringe</td>
			<td style="width:149px;">BD</td>
			<td style="width:119px;">309604</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:224px;">Glass wool</td>
			<td style="width:149px;">Pyrex</td>
			<td style="width:119px;">3950</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:224px;">1-way stopcocks</td>
			<td style="width:149px;">World Precision Instruments, Inc.</td>
			<td style="width:119px;">14054-10</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:224px;">50 ml conical centrifuge tubes</td>
			<td style="width:149px;">World Wide Medical Products</td>
			<td style="width:119px;">41021039</td>
			<td>Used as collection tubes</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:224px;">15 ml conical centrifuge tubes</td>
			<td style="width:149px;">World Wide Medical Products</td>
			<td style="width:119px;">41021037</td>
			<td>Used for cell collection</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:224px;">Fetal Bovine Serum</td>
			<td style="width:149px;">Sigma</td>
			<td style="width:119px;">F6178</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:224px;">0.05% Trypsin&#160;</td>
			<td style="width:149px;">Mediatech, Inc.</td>
			<td style="width:119px;">25-053-CI</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:224px;">100X20mm Cell Culture Dishes</td>
			<td style="width:149px;">Greiner Bio-One</td>
			<td style="width:119px;">664160</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">Name</td>
			<td style="width:149px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">Culture media</td>
			<td style="width:149px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">Osteoblast culture media&#160;</td>
			<td style="width:149px;">PromoCell</td>
			<td style="width:119px;">C-27001</td>
			<td>For human osteoblast media&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">RPMI 1640 media</td>
			<td style="width:149px;">Mediatech, Inc.</td>
			<td style="width:119px;">15-040</td>
			<td>For tumor media prepation&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">Name</td>
			<td style="width:149px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">Cell lines</td>
			<td style="width:149px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">Adherent Cells</td>
			<td style="width:149px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:224px;">Human Osteoblasts</td>
			<td style="width:149px;">PromoCell</td>
			<td style="width:119px;">C-12720</td>
			<td style="width:243px;">Human osteoblast were cultured according to the supplier&#8217;s recommendations.&#160;</td>
		</tr>
		<tr height="210">
			<td height="210" style="height:210px;width:224px;">Human Bone Morrow Stromal Cells</td>
			<td style="width:149px;">WVU Biospecimen Core</td>
			<td style="width:119px;"></td>
			<td style="width:243px;">De-identified primary human leukemia and bone marrow stromal cells (BMSC) were provided by the Mary Babb Randolph Cancer Center (MBRCC) Biospecimen Processing Core and the West Virginia University Department of Pathology Tissue Bank. BMSC cultures were established as previously described (*)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">Leukemic Cells:</td>
			<td style="width:149px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:224px;">REH</td>
			<td style="width:149px;">ATCC</td>
			<td style="width:119px;">ATCC-CRL-8286</td>
			<td style="width:243px;">REH cells were cultured according to the supplier&#8217;s recommendations and recommended media.&#160;</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:224px;">SD-1</td>
			<td style="width:149px;">DSMZ</td>
			<td style="width:119px;">ACC 366</td>
			<td style="width:243px;">SD-1 were cultured according to the supplier&#8217;s recommendations and recommended media.&#160;</td>
		</tr>
		<tr height="48">
			<td colspan="4" height="48" style="height:48px;width:735px;">(*) Gibson LF, Fortney J, Landreth KS, Piktel D, Ericson SG, Lynch JP. Disruption of bone marrow stromal cell function by etoposide. Biol Blood Marrow Transplant J Am Soc Blood Marrow Transplant. 1997 Aug;3(3):122&#8211;32.&#160;</td>
		</tr>
	</tbody>
</table>

modeling chemotherapy resistant leukemia in vitro

It is well established that the bone marrow microenvironment provides a unique site of sanctuary for hematopoietic diseases that both initiate and progress in this site. The model presented in the current report utilizes human primary bone marrow stromal cells and osteoblasts as two representative cell types from the marrow niche that influence tumor cell phenotype. The in vitro co-culture conditions described for human leukemic cells with these primary niche components support the generation of a chemoresistant subpopulation of tumor cells that can be efficiently recovered from culture for analysis by diverse techniques. A strict feeding schedule to prevent nutrient fluxes followed by gel type 10 cross-linked dextran (G10) particles recovery of the population of tumor cells that have migrated beneath the adherent bone marrow stromal cells (BMSC) or osteoblasts (OB) generating a "phase dim" (PD) population of tumor cells, provides a consistent source of purified therapy resistant leukemic cells. This clinically relevant population of tumor cells can be evaluated by standard methods to investigate apoptotic, metabolic, and cell cycle regulatory pathways as well as providing a more rigorous target in which to test novel therapeutic strategies prior to pre-clinical investigations targeted at minimal residual disease.

Successful setup and culture of this co-culture model will result in the establishment of 3 subpopulations of leukemic cells relative to the adherent BMSC or OB monolayer. Figure 1 shows how ALL cells seeded into a BMSC monolayer initially appear as only a single population of suspended leukemic cells. Over the course of 4 days leukemic cells interact with the BMSC to form 3 spatial subpopulations of leukemic cells (suspended (S), phase bright (PB), and phase dim (PD)). W...

Watch this Scientific Journal Video about Modeling Chemotherapy Resistant Leukemia In Vitro at JoVE.com

Modeling Chemotherapy Resistant Leukemia In Vitro

The current report summarizes a protocol that can be utilized to model the influence of the bone marrow microenvironment niche on leukemic cells with emphasis placed on enrichment of the most chemoresistant subpopulation.

Modeling Chemotherapy Resistant Leukemia In Vitro

It is well established that the bone marrow microenvironment provides a unique site of sanctuary for hematopoietic diseases that both initiate and ...

The overall goal of this procedure, is to better model resistant acute lymphoblastic leukemia, or ALL, in vitro. This method can help answer key questions in the treatment of refractory ALL about how the bone marrow microenvironment influences ALL cell chemotherapeutic resistance. The main advantages of this technique are that it is considerably cheaper and less time consuming than utilizing traditional animal models to examine drug advocacy on refractory ALL cells.Begin by seeding five to 20 times 10 to the sixth leukemic cells in 10 milliliters of tumor-specific culture medium onto a 100 millimeter plate of 80 to 90%confluent bone marrow stromal cells or osteoblasts. Every fourth day, tilt the plate to the side and aspirate all but one milliliter of the medium, taking care not to disturb the adherent cell layer. Then, carefully add nine milliliters of fresh leukemic cell culture medium dropwise into the corner of the plate along the side to ensure a minimal disruption of the adherent cells.After the 12th day of co-culture, gently pipette the culture medium up and down over the plate approximately five to 10 times to collect the floating leukemic cells. And transfer the cells into a 15 milliliter conical tube. Then, reseed the cells onto a new plate of 80 to 90%confluent bone marrow stromal cells, or osteoblasts, as just demonstrated.By day four, three subpopulations of leukemic cells will have formed, with the suspended leukemic cells freely floating in the medium. The Phase Bright leukemic cells adhere to the surface of the adherent cell monolayer, and the Phase Dim leukemic cells migrated beneath the monolayer. To prepare the G10 bead columns, first rewarm 30 milliliters of cell culture medium per column to 37 degrees Celsius in a water bath.Next, use tweezers to pull glass wool into thin, loose strands. And add multiple layers of lightly packed strands to one 10 milliliter syringe per column needed. When the syringe is 2/3 full, attach a one-way stopcock in the closed position to the tip, and clamp the syringe onto a ring stand high enough that a 50 milliliter conical collection tube can be placed beneath the stopcock.Now, place a collection tube under the syringe column. And use a 10 milliliter pipette to add drops of G10 particles, suspended in PBS, on top of the glass wool. Continue adding the G10 particles until a two milliliter pellet forms.Then, add two milliliter aliquots of the pre-warmed medium to the column. And slowly open the stopcock valve, so that the medium flows out of the column dropwise. When 10 milliliters of medium have fully drained through the column, close the stopcock.Discard the flow-through, and place a new collection tube under the column. To harvest the suspended tumor subpopulation, aspirate the medium from the leukemic cell co-culture plate, and use the same medium to gently rinse the plate one time. Then, transfer the floating suspension leukemic cell subpopulation into a 15 milliliter conical tube.To harvest the Phase Bright tumor subpopulation, add 10 milliliters of fresh medium back onto the co-culture plate. And rinse approximately five times vigorously enough to remove the adherent leukemic cells without dislodging the adherent cell monolayer. Then, transfer the Phase Bright subpopulation into its own 15 milliliter conical tube.To harvest the Phase Dim tumor subpopulation, remove the remaining medium with a one milliliter PBS rinse. And detach the cells with three milliliters of trypsin at 37 degrees Celsius. After five minutes, gently tap the sides of the plate to dislodge the adherent cells, followed by the addition of one milliliter of FBS to stop the enzymatic reaction.Then, rinse the serum three to five times to break apart any large cell aggregates. And transfer the unpurified Phase Dim subpopulation into a new 15 milliliter conical tube. When all of the subpopulations have been collected, spin down the cells.And re-suspend each of the pellets in one milliliter of pre-warmed medium. With the stopcock completely closed, for each subpopulation, use a 1, 000 microliter pipette to add the entire one milliliter volume of cells, dropwise, onto the top of one of the prepared G10 columns, making sure the cells remain on top of, or within, the G10 pellet. Allow the cells to incubate on the G10 pellet for 20 minutes at room temperature.Then, add one to three milliliters of fresh pre-warmed medium to the column. And open the stopcock so that the medium slowly exits the columns, dropwise. Continue to add pre-warmed medium to the columns, in one to two milliliter increments.When a total of 15 to 20 milliliters of leukemic cells has been collected, close the stopcock and cap the collection tube. Then, spin down the cells and re-suspend the pellet in the appropriate downstream analysis buffer. Following trypsinization of the adherent cell layer, two distinct populations of cells are observed by forward versus side scatter analysis.After G10 separation, a pure population of ALL cells is recovered. Of particular interest, all of the Phase Dim cells recovered from bone marrow stromal cell, or osteoblast co-cultures, exhibit little to no death following their exposure to cytotoxic chemotherapy. While attempting these procedures, it's important to remember to perform these steps as properly as possible to reduce any phenotypic changes that may occur in the leukemic cells.This technique provides a way for researchers in the field of leukemia research to model the chemotherapy-resistant leukemia in an in vitro model that more closely resembles the bone marrow microenvironment.

modeling-chemotherapy-resistant-leukemia-in-vitro

Research

JoVE Journal

Medicine

Multi-modal Imaging of Angiogenesis in a Nude Rat Model of Breast Cancer Bone Metastasis Using Magnetic Resonance Imaging, Volumetric Computed Tomography and Ultrasound

Angiogenesis is an essential feature of cancer growth and metastasis formation. In bone metastasis, angiogenic factors are pivotal for tumor cell proliferation in the bone marrow cavity as well as for interaction of tumor and bone cells resulting in local bone destruction. Our aim was to develop a model of experimental bone metastasis that allows in vivo assessment of angiogenesis in skeletal lesions using non-invasive imaging techniques.
For this purpose, we injected 105 MDA-MB-231 human breast cancer cells into the superficial epigastric artery, which precludes the growth of metastases in body areas other than the respective hind leg1. Following 25-30 days after tumor cell inoculation, site-specific bone metastases develop, restricted to the distal femur, proximal tibia and proximal fibula1. Morphological and functional aspects of angiogenesis can be investigated longitudinally in bone metastases using magnetic resonance imaging (MRI), volumetric computed tomography (VCT) and ultrasound (US).
MRI displays morphologic information on the soft tissue part of bone metastases that is initially confined to the bone marrow cavity and subsequently exceeds cortical bone while progressing. Using dynamic contrast-enhanced MRI (DCE-MRI) functional data including regional blood volume, perfusion and vessel permeability can be obtained and quantified2-4. Bone destruction is captured in high resolution using morphological VCT imaging. Complementary to MRI findings, osteolytic lesions can be located adjacent to sites of intramedullary tumor growth. After contrast agent application, VCT angiography reveals the macrovessel architecture in bone metastases in high resolution, and DCE-VCT enables insight in the microcirculation of these lesions5,6. US is applicable to assess morphological and functional features from skeletal lesions due to local osteolysis of cortical bone. Using B-mode and Doppler techniques, structure and perfusion of the soft tissue metastases can be evaluated, respectively. DCE-US allows for real-time imaging of vascularization in bone metastases after injection of microbubbles7.
In conclusion, in a model of site-specific breast cancer bone metastases multi-modal imaging techniques including MRI, VCT and US offer complementary information on morphology and functional parameters of angiogenesis in these skeletal lesions.

In the pathogenesis of bone metastasis, angiogenesis is a crucial process and therefore represents a target for imaging and therapy. Here, we present a rat model of site-specific breast cancer bone metastasis and describe strategies to non-invasively image angiogenesis in vivo using magnetic resonance imaging, volumetric computed tomography and ultrasound.

Angiogenesis is an essential feature of cancer growth and metastasis formation. In bone metastasis, angiogenic factors are pivotal for tumor cell ...

Heterotypic Three-dimensional In Vitro Modeling of Stromal-Epithelial Interactions During Ovarian Cancer Initiation and Progression

Epithelial ovarian cancers (EOCs) are the leading cause of death from gynecological malignancy in Western societies. Despite advances in surgical treatments and improved platinum-based chemotherapies, there has been little improvement in EOC survival rates for more than four decades 1,2. Whilst stage I tumors have 5-year survival rates &gt;85%, survival rates for stage III/IV disease are &lt;40%. Thus, the high rates of mortality for EOC could be significantly decreased if tumors were detected at earlier, more treatable, stages 3-5. At present, the molecular genetic and biological basis of early stage disease development is poorly understood. More specifically, little is known about the role of the microenvironment during tumor initiation; but known risk factors for EOCs (e.g. age and parity) suggest that the microenvironment plays a key role in the early genesis of EOCs. We therefore developed three-dimensional heterotypic models of both the normal ovary and of early stage ovarian cancers. For the normal ovary, we co-cultured normal ovarian surface epithelial (IOSE) and normal stromal fibroblast (INOF)&nbsp;cells, immortalized by retrovrial transduction of the catalytic subunit of human telomerase holoenzyme (hTERT) to extend the lifespan of these cells in culture. To model the earliest stages of ovarian epithelial cell transformation, overexpression of the CMYC oncogene in IOSE cells, again co-cultured with INOF cells. These heterotypic models were used to investigate the effects of aging and senescence on the transformation and invasion of epithelial cells. Here we describe the methodological steps in development of these three-dimensional model; these methodologies aren't specific to the development of normal ovary and ovarian cancer tissues, and could be used to study other tissue types where stromal and epithelial cell interactions are a fundamental aspect of the tissue maintenance and disease development.

Heterotypic Three-dimensional In Vitro Modeling of Stromal-Epithelial Interactions During Ovarian Cancer Initiation and Progression

We describe methodologies for establishing in vitro heterotypic three-dimensional models comprising ovarian fibroblasts and normal ovarian surface or ovarian cancer epithelial cells. We discuss the use of these models to study stromal-epithelial interactions that occur during ovarian cancer development.

Epithelial ovarian cancers (EOCs) are the leading cause of death from gynecological malignancy in Western societies. Despite advances in surgical ...

Quantitative Multispectral Analysis Following Fluorescent Tissue Transplant for Visualization of Cell Origins, Types, and Interactions

With the desire to understand the contributions of multiple cellular elements to the development of a complex tissue; such as the numerous cell types that participate in regenerating tissue, tumor formation, or vasculogenesis, we devised a multi-colored cellular transplant model of tumor development in which cell populations originate from different fluorescently colored reporter gene mice and are transplanted, engrafted or injected in and around a developing tumor. These colored cells are then recruited and incorporated into the tumor stroma. In order to quantitatively assess bone marrow derived tumor stromal cells, we transplanted GFP expressing transgenic whole bone marrow into lethally irradiated RFP expressing mice as approved by IACUC. 0ovarian tumors that were orthotopically injected into the transplanted mice were excised 6-8 weeks post engraftment and analyzed for bone marrow marker of origin (GFP) as well as antibody markers to detect tumor associated stroma using multispectral imaging techniques. We then adapted a methodology we call MIMicc- Multispectral Interrogation of Multiplexed cellular compositions, using multispectral unmixing of fluoroprobes to quantitatively assess which labeled cell came from which starting populations (based on original reporter gene labels), and as our ability to unmix 4, 5, 6 or more spectra per slide increases, we&#39;ve added additional immunohistochemistry associated with cell lineages or differentiation to increase precision. Utilizing software to detect co-localized multiplexed-fluorescent signals, tumor stromal populations can be traced, enumerated and characterized based on marker staining.1

Complex tissue masses, from organs to tumors, are composed of various cellular elements. We elucidated the contribution of cellular phenotypes within a tissue utilizing multi-labeled fluorescent transgenic mice in combination with multiparameter immunofluorescent staining followed by spectral unmixing to decipher cell origin as well as cell characteristics based on protein expression.

With the desire to understand the contributions of multiple cellular elements to the development of a complex tissue; such as the numerous cell types that ...

Pre-clinical Evaluation of Tyrosine Kinase Inhibitors for Treatment of Acute Leukemia

Receptor tyrosine kinases have been implicated in the development and progression of many cancers, including both leukemia and solid tumors, and are attractive druggable therapeutic targets. Here we describe an efficient four-step strategy for pre-clinical evaluation of tyrosine kinase inhibitors (TKIs) in the treatment of acute leukemia. Initially, western blot analysis is used to confirm target inhibition in cultured leukemia cells. Functional activity is then evaluated using clonogenic assays in methylcellulose or soft agar cultures. Experimental compounds that demonstrate activity in cell culture assays are evaluated in vivo using NOD-SCID-gamma (NSG) mice transplanted orthotopically with human leukemia cell lines. Initial in vivo pharmacodynamic studies evaluate target inhibition in leukemic blasts isolated from the bone marrow. This approach is used to determine the dose and schedule of administration required for effective target inhibition. Subsequent studies evaluate the efficacy of the TKIs in vivo using luciferase expressing leukemia cells, thereby allowing for non-invasive bioluminescent monitoring of leukemia burden and assessment of therapeutic response using an in vivo bioluminescence imaging system. This strategy has been effective for evaluation of TKIs in vitro and in vivo and can be applied for identification of molecularly-targeted agents with therapeutic potential or for direct comparison and prioritization of multiple compounds.

Receptor tyrosine kinases are ectopically expressed in many cancers and have been identified as therapeutic targets in acute leukemia. This manuscript describes an efficient strategy for pre-clinical evaluation of tyrosine kinase inhibitors for the treatment of acute leukemia.

Receptor tyrosine kinases have been implicated in the development and progression of many cancers, including both leukemia and solid tumors, and are ...

Modeling Spontaneous Metastatic Renal Cell Carcinoma (mRCC) in Mice Following Nephrectomy

One of the key challenges to improved testing of new experimental therapeutics in renal cell carcinoma (RCC) is the development of models that faithfully recapitulate early- and late-stage metastatic disease progression. Typical tumor implantation models utilize ectopic or orthotopic primary tumor implantation, but few include systemic spontaneous metastatic disease that mimics the clinical setting. This protocol describes the key steps to develop RCC disease progression stages similar to patients. First, it uses a highly metastatic mouse tumor cell line in a syngeneic model to show orthotopic tumor cell implantation. Methods include superficial and internal implantation into the sub-capsular space with cells combined with matrigel to prevent leakage and early spread. Next it describes the procedures for excision of tumor-bearing kidney (nephrectomy), with critical pre- and post- surgical mouse care. Finally, it outlines the steps necessary to monitor and assess micro-and macro-metastatic disease progression, including bioluminescent imaging as well provides a detailed visual necropsy guide to score systemic disease distribution. The goal of this protocol description is to facilitate the widespread use of clinically relevant metastatic RCC models to improve the predictive value of future therapeutic testing.&#160;

Modeling Spontaneous Metastatic Renal Cell Carcinoma mRCC in Mice Following Nephrectomy

Models of spontaneous metastatic renal cell carcinoma (RCC) disease progression can be used for evaluating treatments in a clinically relevant setting. This protocol demonstrates different procedures for orthotopic kidney tumor cell implantation, proper nephrectomy, and finally outlines a necropsy guide for visual and bioluminescent scoring of metastatic burden and localization.

One of the key challenges to improved testing of new experimental therapeutics in renal cell carcinoma (RCC) is the development of models that faithfully ...

Chemotherapy-induced Vascular Toxicity - Real-time In vivo Imaging of Vessel Impairment

Certain classes of chemotherapies may exert acute vascular changes that may progress into long-term conditions that may predispose the patient to an increased risk of vascular morbidity.&#160;Yet, albeit&#160;the mounting clinical evidence, there is a paucity of clear studies of vascular toxicity and therefore the etiology of a heterogeneous group of vascular/cardiovascular disorders remains to be elucidated. Moreover, the mechanism that may underlie vascular toxicity can completely differ from the principles of chemotherapy-induced cardiotoxicity, which is related to direct myocyte injury. We have established a real-time, in vivo molecular imaging platform&#160;to evaluate&#160;the potential&#160;acute&#160;vascular toxicity of anti-cancer therapies.
We have set up a platform of in vivo, high-resolution molecular imaging&#160;in mice,&#160;suitable for visualizing vasculature within confined organs and reference blood vessels within the same individuals whereas each individual serve as its own control. Blood vessel walls were impaired after doxorubicin administration, representing a unique mechanism of vascular toxicity that may be the early event in end-organ injury. Herein, the method of fibered confocal fluorescent microscopy (FCFM) based imaging is described, which provides an innovative mode to understand physiological phenomena at the cellular and sub-cellular levels in animal subjects.

Chemotherapy-induced Vascular Toxicity - Real-time In vivo Imaging of Vessel Impairment

We herein describe the method of fibered confocal fluorescent microscopy (FCFM) based imaging, which provides an innovative mode to understand physiological phenomena at the cellular and sub-cellular levels in animal subjects.

Certain classes of chemotherapies may exert acute vascular changes that may progress into long-term conditions that may predispose the patient to an ...

From a 2DE-Gel Spot to Protein Function: Lesson Learned From HS1 in Chronic Lymphocytic Leukemia

The identification of molecules involved in tumor initiation and progression is fundamental for understanding disease&#8217;s biology and, as a consequence, for the clinical management of patients. In the present work we will describe an optimized proteomic approach for the identification of molecules involved in the progression of Chronic Lymphocytic Leukemia (CLL). In detail, leukemic cell lysates are resolved by 2-dimensional Electrophoresis (2DE) and visualized as &#8220;spots&#8221; on the 2DE gels. Comparative analysis of proteomic maps allows the identification of differentially expressed proteins (in terms of abundance and post-translational modifications) that are picked, isolated and identified by Mass Spectrometry (MS). The biological function of the identified candidates can be tested by different assays (i.e. migration, adhesion and F-actin polymerization), that we have optimized for primary leukemic cells.

Here we describe a protocol that couples two proteomic techniques, namely 2-dimensional Electrophoresis (2DE) and Mass Spectrometry (MS), to identify differentially expressed/post-translational modified proteins among two or more groups of primary samples. This approach, together with functional experiments, allows the identification and characterization of prognostic markers/therapeutic targets.

The identification of molecules involved in tumor initiation and progression is fundamental for understanding disease&#8217;s biology and, as a ...

MRI-guided dmPFC-rTMS as a Treatment for Treatment-resistant Major Depressive Disorder

Here we outline the protocol for magnetic resonance imaging (MRI) guided repetitive transcranial magnetic stimulation (rTMS) to the dorsal medial prefrontal cortex (dmPFC) in patients with major depressive disorder (MDD). Technicians used a neuronavigation system to process patient MRIs to generate a 3-dimensional head model. The head model was subsequently used to identify patient-specific stimulatory targets. The dmPFC was stimulated daily for 20 sessions. Stimulation intensity was titrated to address scalp pain associated with rTMS. Weekly assessments were conducted on the patients using the Hamilton Rating Scale for Depression (HamD17) and Beck Depression Index II (BDI-II). Treatment-resistant MDD patients achieved significant improvements on both HAMD and BDI-II. Of note, angled, double-cone coil rTMS at 120% resting motor threshold allows for optimal stimulation of deeper midline prefrontal regions, which results in a possible therapeutic application for MDD. One major limitation of the rTMS field is the heterogeneity of treatment parameters across studies, including duty cycle, number of pulses per session and intensity. Further work should be done to clarify the effect of stimulation parameters on outcome. Future dmPFC-rTMS work should include sham-controlled studies to confirm its clinical efficacy in MDD.

Here we outline the procedure for MRI-guided repetitive transcranial magnetic stimulation to the dorsomedial prefrontal cortex as an experimental treatment for major depressive disorder.

Here we outline the protocol for magnetic resonance imaging (MRI) guided repetitive transcranial magnetic stimulation (rTMS) to the dorsal medial ...

Modeling Myotonic Dystrophy 1 in C2C12 Myoblast Cells

Myotonic dystrophy 1 (DM1) is a common form of muscular dystrophy. Although several animal models have been established for DM1, myoblast cell models are still important because they offer an efficient cellular alternative for studying cellular and molecular events. Though C2C12 myoblast cells have been widely used to study myogenesis, resistance to gene transfection, or viral transduction, hinders research in C2C12 cells. Here, we describe an optimized protocol that includes daily maintenance, transfection and transduction procedures to introduce genes into C2C12 myoblasts and the induction of myocyte differentiation. Collectively, these procedures enable best transfection/transduction efficiencies, as well as consistent differentiation outcomes. The protocol described in establishing DM1 myoblast cell models would benefit the study of myotonic dystrophy, as well as other muscular diseases.

In this protocol, we present the procedures in establishing myotonic dystrophy 1 myoblast models, including optimized C2C12 cell maintenance, gene transfection/transduction, and myocyte differentiation.

Myotonic dystrophy 1 (DM1) is a common form of muscular dystrophy. Although several animal models have been established for DM1, myoblast cell models are ...

Network Analysis of Foramen Ovale Electrode Recordings in Drug-resistant Temporal Lobe Epilepsy Patients

Approximately 30% of epilepsy patients are refractory to antiepileptic drugs. In these cases, surgery is the only alternative to eliminate/control seizures. However, a significant minority of patients continues to exhibit post-operative seizures, even in those cases in which the suspected source of seizures has been correctly localized and resected. The protocol presented here combines a clinical procedure routinely employed during the pre-operative evaluation of temporal lobe epilepsy (TLE) patients with a novel technique for network analysis. The method allows for the evaluation of the temporal evolution of mesial network parameters. The bilateral insertion of foramen ovale electrodes (FOE) into the ambient cistern simultaneously records electrocortical activity at several mesial areas in the temporal lobe. Furthermore, network methodology applied to the recorded time series tracks the temporal evolution of the mesial networks both interictally and during the seizures. In this way, the presented protocol offers a unique way to visualize and quantify measures that considers the relationships between several mesial areas instead of a single area.

This protocol describes a procedure to track the evolution of mesial network measures in temporal lobe epilepsy (TLE) patients. It is based on the combination of intracranial recordings with a novel numerical technique for data analysis. Specifically, we present a protocol for network analyses of foramen ovale recordings.