We would like to thank the staff of the Tissue Procurement Facility of the University of Minnesota for assistance with patient tissue samples collection. This work was supported by the Department of Defense Ovarian Cancer Research Program (OCRP) OC093424 to MB, by the Randy Shaver Cancer Research and Community Fund to MB, by the Minnesota Ovarian Cancer Alliance to MB and by the Gynecological Oncology Departmental fund to MB. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.

Ethics Statement&#160; 
Solid specimens of ovarian cancer were obtained from the University of Minnesota Tissue Procurement Facility (TPF) after Institutional Review Board Committee: Human Subject Board (IRB) approval.
1. Reagent Setup
<ol>
	<li>Prepare Complete DMEM medium by supplementing DMEM with 10% FBS, and 100 units penicillin-streptomycin. Store the medium at 4&#160;&#176;C and warm to 37&#160;&#176;C prior to use.</li>
	<li>Aliquot dispase II into separate volumes of 5-10 ml to avoid multiple freeze thaws and store at -20&#160;&#176;C in a nonfrost-free freezer.</li>
</ol>
2. Tissue Collection
<ol>
	<li>Collect solid specimens of ovarian cancer (~5 g in size) at the time of surgery from areas macroscopically identified as cancer by a pathologist. Clinical specimens are de-identified and registered according to institutional protocols.</li>
	<li>Place specimens in a sterile, screw lid, polypropylene specimens container filled with 30 ml of ice-cold PBS. Transport the specimens from the surgical pathology laboratory to the research laboratory for processing on ice, and within 30 min&#160;from specimen collection&#160;(Figure 1).</li>
</ol>
3. Tissue Processing
<ol>
	<li>Working under sterile conditions, transfer the samples onto a Petri dish (60 mm x&#160;60 mm) containing 10 ml of fresh, ice-cold PBS and using a sterile razor blade, further cut into the smallest pieces possible (2 mm or less)&#160;(Figures 2A and 2B).</li>
	<li>Transfer the minced tissues into a 15 ml conic tube containing 10 ml of prewarmed (37 &#176;C for 30 min) dispase II (2.4 U/ml) in DMEM and incubate at 5% CO2 and 37 &#176;C for 30 min. To ensure optimal digestion of the specimens, manually agitate the cell slurry every 5 min.</li>
	<li>After 30 min&#160;incubation, transfer (using a 10 ml serological pipette) the cell slurry onto a cell strainer&#160;(70 &#956;m mesh) placed on top of a 50 ml conical tube and apply a gentle pressure against the mesh using a syringe plunger. Discard any undissociated tissue (remaining on the top of the mesh) and collect the obtained cell suspension in the 50 ml sterile conical tube. Centrifuge at 320 x g for 7 min&#160;at 4 &#176;C&#160;(Figure 3).</li>
	<li>Discard the supernatant and resuspend the cell pellet in 10 ml of DMEM containing 10% FBS.</li>
	<li>Incubate the cell suspension in a Petri dish at 5% CO2 and 37 &#176;C&#160;(Figure 4).</li>
	<li>Change the medium after 24 hr&#160;from the initial plating. This allows for removal of cellular debris and the majority of the erythrocytes present in culture.</li>
	<li>Change the medium every three days for the following two weeks, after which the cultures of primary EOC are ready for downstream applications.</li>
</ol>

<ol>
	<li>Kurman, R. J., Visvanathan, K., Roden, R., Wu, T. C., Ie M, S. h. i. h. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+detection+and+treatment+of+ovarian+cancer:+shifting+from+early+stage+to+minimal+volume+of+disease+based+on+a+new+model+of+carcinogenesis.">Early detection and treatment of ovarian cancer: shifting from early stage to minimal volume of disease based on a new model of carcinogenesis.</a> Am. J. Obstet. Gynecol. 198 (4), 351-356 (2008).</li><li>Kuhn, E., Kurman, R. J., Shih, I. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ovarian+Cancer+Is+an+Imported+Disease:+Fact+or+Fiction.">Ovarian Cancer Is an Imported Disease: Fact or Fiction.</a> Curr. Obstet. Gynecol. Rep. 1 (1), 1-9 (2012).</li><li>Sarojini, 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=Early+detection+biomarkers+for+ovarian.">Early detection biomarkers for ovarian.</a> J. Oncol. , (2012).</li><li>Shepherd, T. G., Theriault, B. L., Campbell, E. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nachtigal+M.W.+Primary+culture+of+ovarian+surface+epithelial+cells+and+ascites-derived+ovarian+cancer+cells+from+patients.">Nachtigal M.W. Primary culture of ovarian surface epithelial cells and ascites-derived ovarian cancer cells from patients.</a> Nat. Protoc. 1 (6), 2643-2649 (2006).</li><li>Tsao, S. W., 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=Characterization+of+human+ovarian+surface+epithelial+cells+immortalized+by+human+papilloma+viral+oncogenes+(HPV-E6E7+ORFs).">Characterization of human ovarian surface epithelial cells immortalized by human papilloma viral oncogenes (HPV-E6E7 ORFs).</a> Exp. Cell. Res. 218 (2), 499-507 (1995).</li><li>Auersperg, N., Maines-Bandiera, S. L., Dyck, H. G., Kruk, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+cultured+human+ovarian+surface+epithelial+cells:+phenotypic+plasticity+and+premalignant+changes.">Characterization of cultured human ovarian surface epithelial cells: phenotypic plasticity and premalignant changes.</a> Lab. Invest. 71 (4), 510-518 (1994).</li><li>Brewer, 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=In+vitro+model+of+normal,+immortalized+ovarian+surface+epithelial+and+ovarian+cancer+cells+for+chemoprevention+of+ovarian+cancer.">In vitro model of normal, immortalized ovarian surface epithelial and ovarian cancer cells for chemoprevention of ovarian cancer.</a> Gynecol. Oncol. 98 (2), 182-192 (2005).</li><li>Sueblinvong, T., 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=Establishment,+characterization+and+downstream+application+of+primary+ovarian+cancer+cells+derived+from+solid+tumors.">Establishment, characterization and downstream application of primary ovarian cancer cells derived from solid tumors.</a> PLoS One. 7 (11), (2012).</li><li>Rockwell, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo-in+vitro+tumour+cell+lines:+characteristics+and+limitations+as+models+for+human+cancer.">In vivo-in vitro tumour cell lines: characteristics and limitations as models for human cancer.</a> Br. J. Cancer Suppl. 41 (4), 118-122 (1980).</li><li>Wong, C., Chen, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+development,+application+and+limitations+of+breast+cancer+cell+lines+to+study+tamoxifen+and+aromatase+inhibitor+resistance.">The development, application and limitations of breast cancer cell lines to study tamoxifen and aromatase inhibitor resistance.</a> J. Steroid. Biochem. Mol. Biol. 131 (3-5), 83-92 (2012).</li></ol>

The authors have nothing to disclose.

A better understanding of ovarian cancer etiology and development is crucial to improving the outcome of women affected by this devastating disease. In this context, the use of established and &#34;commercially available&#34; ovarian cancer cell line has undoubtedly been tremendously useful. However, today we know that cancer cell lines are not representative of the human tumor they originated from in many aspects including the lack of heterogeneity9,10.
Here, we report a rapid and ...

Despite its relatively low incidence, ovarian cancer is the deadliest of the gynecological diseases and the fifth leading cause of cancer deaths among women1,2. This is mainly due to the lack of reliable tools and models that faithfully recapitulate the initiation and progression of the disease3. Most of our knowledge today about ovarian cancer has been possible through the use of immortalized ovarian surface epithelial cells (IOSEs), ovarian cancer cell lines and primary ovarian cancer cells recovered from ascitic fluid4-7. Unfortunately, their use has several limitations including a number of genetic and phenotypic changes associated with immortalization process or in vitro passages and the heterogeneity of the population resulting from ascitic fluid preparation.
Therefore, primary ovarian cancer cells derived from identifiable and specific solid specimens of ovarian cancer represent a unique tool for studying ovarian cancer progression.
The main difficulties involved in the obtaining these malignant cells are due to an overgrowth of stromal cells or fibroblasts along with loss of viability and premature lack of proliferative capacity in the culture of these EOC cells. Several methods to create single-cell suspensions from solid tumors currently exist, through mechanical means or enzymatic dissociation, however certain techniques yield a greater amount of the preferred outcome8. Here, we show that enzymatic digestion with dispase II results in an effective recovery of viable, fibroblast-free EOC cells. The so-obtained EOC cultures are highly susceptible to genetic manipulation and are also useful in drug screening tests, indicating that these EOC cultures are suitable for many downstream applications.

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		<col />
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	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:275px;">Name of Material/ Equipment</td>
			<td style="width:125px;">Company</td>
			<td style="width:155px;">Catalog Number</td>
			<td style="width:167px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">REAGENTS:</td>
			<td style="width:125px;"></td>
			<td style="width:155px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td style="width:125px;"></td>
			<td style="width:155px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">1X PBS, sterile&#160;</td>
			<td style="width:125px;">Invitrogen</td>
			<td style="width:155px;">14190-144</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td style="width:125px;"></td>
			<td style="width:155px;"></td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">&#160;Screw lid, polypropylene specimen container, sterile (Thermoscientific)</td>
			<td style="width:125px;">Thermoscientific</td>
			<td style="width:155px;">02 1090</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td style="width:125px;"></td>
			<td style="width:155px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">&#160;DMEM medium, sterile&#160;</td>
			<td style="width:125px;">Invitrogen</td>
			<td style="width:155px;">11995-065</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td style="width:125px;"></td>
			<td style="width:155px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">&#160;Fetal bovine serum, sterile</td>
			<td style="width:125px;">Thermo Scientific Hyclone</td>
			<td style="width:155px;">SH30396.03</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td style="width:125px;"></td>
			<td style="width:155px;"></td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">&#160;100x penicillin-streptomycin, liquid (Invitrogen)</td>
			<td style="width:125px;">Invitrogen</td>
			<td style="width:155px;">15140-122</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td style="width:125px;"></td>
			<td style="width:155px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">&#160;Dispase II, sterile (Roche)</td>
			<td style="width:125px;">Roche</td>
			<td style="width:155px;">04942 078 001</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td style="width:125px;"></td>
			<td style="width:155px;"></td>
			<td></td>
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		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td style="width:125px;"></td>
			<td style="width:155px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">&#160;Small fine-tip forceps and scalpel blade, sterile</td>
			<td style="width:125px;">Fisher Scientific</td>
			<td style="width:155px;">forceps: 08-953E, blades: 08-927-5D</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td style="width:125px;"></td>
			<td style="width:155px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">&#160;Small dissecting scissors, sterile</td>
			<td style="width:125px;">Fisher Scientific</td>
			<td style="width:155px;">08-945</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td style="width:125px;"></td>
			<td style="width:155px;"></td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">&#160;15 ml conical capped tubes, sterile (BD Falcon)</td>
			<td style="width:125px;">BD, Falcon</td>
			<td align="right" style="width:155px;">352097</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td style="width:125px;"></td>
			<td style="width:155px;"></td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">50 ml conical capped tubes, sterile (BD Falcon)</td>
			<td style="width:125px;">BD, Falcon</td>
			<td align="right" style="width:155px;">352027</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td style="width:125px;"></td>
			<td style="width:155px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">&#160;10 ml serological pipette, sterile&#160;</td>
			<td style="width:125px;">Corning</td>
			<td style="width:155px;">13-678-11E</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td style="width:125px;"></td>
			<td style="width:155px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">6 ml syringe plunger, sterile&#160;</td>
			<td style="width:125px;">Tyco Healthcare</td>
			<td align="right" style="width:155px;">8881516911</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td style="width:125px;"></td>
			<td style="width:155px;"></td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Nylon filter (70 &#956;m ) cell strainer, sterile (BD Falcon)</td>
			<td style="width:125px;">BD Falcon</td>
			<td align="right" style="width:155px;">352350</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td style="width:125px;"></td>
			<td style="width:155px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">5-cm Petri dish, sterile&#160;</td>
			<td style="width:125px;">Corning</td>
			<td align="right" style="width:155px;">430166</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td style="width:125px;"></td>
			<td style="width:155px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">10-cm Petri dish, sterile&#160;</td>
			<td style="width:125px;">Corning</td>
			<td align="right" style="width:155px;">430167</td>
			<td></td>
		</tr>
	</tbody>
</table>

method for obtaining primary ovarian cancer cells from solid specimens

Reliable tools for investigating ovarian cancer initiation and progression are urgently needed. While the use of ovarian cancer cell lines remains a valuable tool for understanding ovarian cancer, their use has many limitations. These include the lack of heterogeneity and the plethora of genetic alterations associated with extended in vitro passaging.&#160;Here we describe a method that allows for rapid establishment of primary ovarian cancer cells form solid clinical specimens collected at the time of surgery. The method consists of subjecting clinical specimens to enzymatic digestion for 30 min. The isolated cell suspension is allowed to grow and can be used for downstream application including drug screening. The advantage of primary ovarian cancer cell lines over established ovarian cancer cell lines is that they are representative of the original specific clinical specimens they are derived from and can be derived from different sites whether primary or metastatic ovarian cancer.

Fresh clinical specimens of ovarian cancer are collected after surgery (Figure 1) and cut in small pieces (Figures 2A and 2B) constituting the cell slurry. This allows for optimal exposure of the specimens to the enzymatic treatment. Cell slurry is exposed to enzymatic digestion and incubated at 37 &#176;C for 30 min. During the incubation time the slurry becomes increasingly cloudy (especially after each agitation) and this is a sign of tissue disaggregation.&#160;At th...

Watch this Scientific Journal Video about Method for Obtaining Primary Ovarian Cancer Cells From Solid Specimens at JoVE.com

Method for Obtaining Primary Ovarian Cancer Cells From Solid Specimens

This study describes a detailed method for isolation and characterization of primary ovarian cancer cells from solid clinical specimens. Ovarian cancer clinical specimens are subjected to enzymatic digestion to obtain viable, fibroblast-free epithelial ovarian cancer (EOC) cells highly suitable for downstream applications.

Reliable tools for investigating ovarian cancer initiation and progression are urgently needed. While the use of ovarian cancer cell lines remains a ...

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13.4K Views.  University of Minnesota. This study describes a detailed method for isolation and characterization of primary ovarian cancer cells from solid clinical specimens. Ovarian cancer clinical specimens are subjected to enzymatic digestion to obtain viable, fibroblast-free epithelial ovarian cancer (EOC) cells highly suitable for downstream applications.

Video: Method for Obtaining Primary Ovarian Cancer Cells From Solid Specimens

Method for Novel Anti-Cancer Drug Development using Tumor Explants of Surgical Specimens

The current therapies for malignant glioma have only palliative effect. For therapeutic development, one hurdle is the discrepancy of efficacy determined by current drug efficacy tests and the efficacy on patients. Thus, novel and reliable methods for evaluating drug efficacy are warranted in pre-clinical phase. In vitro culture of tumor tissues, including cell lines, has substantial phenotypic, genetic, and epigenetic alterations of cancer cells caused by artificial environment of cell culture, which may not reflect the biology of original tumors in situ. Xenograft models with the immunodeficient mice also have limitations, i.e., the lack of immune system and interspecies genetic and epigenetic discrepancies in microenvironment. Here, we demonstrate a novel method using the surgical specimens of malignant glioma as undissociated tumor blocks to evaluate treatment effects. To validate this method, data with the current first-line chemotherapeutic agent, temozolomide (TMZ), are described.


We used the freshly-removed surgical specimen of malignant glioma for our experiments. We performed intratumoral injection of TMZ or other drug candidates, followed by incubation and analysis on surgical specimens. Here, we sought to establish a tumor tissue explant method as a platform to determine the efficacy of novel anti-cancer therapies so that we may be able to overcome, at least, some of the current limitations and fill the existing gap between the current experimental data and the efficacy on an actual patient's tumor. This method may have the potential to accelerate identifying novel chemotherapeutic agents for solid cancer treatment.

Here, we established a method for drug efficacy testing with surgical specimens of brain tumors, termed &#x201C;tumor explant method&#x201D;. With this method, we can evaluate drug efficacy without breaking the microenvironment of solid tumors. To validate reliability of this method, we describe representative data with our glioma specimen treated with the current first-line chemotherapeutic agent, temozolomide.


The current therapies for malignant glioma have only palliative effect. For therapeutic development, one hurdle is the discrepancy of efficacy determined ...

Identification of Sleeping Beauty Transposon Insertions in Solid Tumors using Linker-mediated PCR

Genomic, proteomic, transcriptomic, and epigenomic analyses of human tumors indicate that there are thousands of anomalies within each cancer genome compared to matched normal tissue. Based on these analyses it is evident that there are many undiscovered genetic drivers of cancer1. Unfortunately these drivers are hidden within a much larger number of passenger anomalies in the genome that do not directly contribute to tumor formation. Another aspect of the cancer genome is that there is considerable genetic heterogeneity within similar tumor types. Each tumor can harbor different mutations that provide a selective advantage for tumor formation2. Performing an unbiased forward genetic screen in mice provides the tools to generate tumors and analyze their genetic composition, while reducing the background of passenger mutations. The Sleeping Beauty (SB) transposon system is one such method3. The SB system utilizes mobile vectors (transposons) that can be inserted throughout the genome by the transposase enzyme. Mutations are limited to a specific cell type through the use of a conditional transposase allele that is activated by Cre Recombinase. Many mouse lines exist that express Cre Recombinase in specific tissues. By crossing one of these lines to the conditional transposase allele (e.g. Lox-stop-Lox-SB11), the SB system is activated only in cells that express Cre Recombinase. The Cre Recombinase will excise a stop cassette that blocks expression of the transposase allele, thereby activating transposon mutagenesis within the designated cell type. An SB screen is initiated by breeding three strains of transgenic mice so that the experimental mice carry a conditional transposase allele, a concatamer of transposons, and a tissue-specific Cre Recombinase allele. These mice are allowed to age until tumors form and they become moribund. The mice are then necropsied and genomic DNA is isolated from the tumors. Next, the genomic DNA is subjected to linker-mediated-PCR (LM-PCR) that results in amplification of genomic loci containing an SB transposon. LM-PCR performed on a single tumor will result in hundreds of distinct amplicons representing the hundreds of genomic loci containing transposon insertions in a single tumor4. The transposon insertions in all tumors are analyzed and common insertion sites (CISs) are identified using an appropriate statistical method5. Genes within the CIS are highly likely to be oncogenes or tumor suppressor genes, and are considered candidate cancer genes. The advantages of using the SB system to identify candidate cancer genes are: 1) the transposon can easily be located in the genome because its sequence is known, 2) transposition can be directed to almost any cell type and 3) the transposon is capable of introducing both gain- and loss-of-function mutations6. The following protocol describes how to devise and execute a forward genetic screen using the SB transposon system to identify candidate cancer genes (Figure 1).

Identification of Sleeping Beauty Transposon Insertions in Solid Tumors using Linker-mediated PCR

A method of identifying unknown drivers of carcinogenesis using an unbiased approach is described. The method uses the Sleeping Beauty transposon as a random mutagen directed to specific tissues. Genomic mapping of transposon insertions that drive tumor formation identifies novel oncogenes and tumor suppressor genes

Genomic, proteomic, transcriptomic, and epigenomic analyses of human tumors indicate that there are thousands of anomalies within each cancer genome ...

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

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

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

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

A Sensitive Method to Quantify Senescent Cancer Cells

Human cells do not indefinitely proliferate. Upon external and/or intrinsic cues, cells might die or enter a stable cell cycle arrest called senescence. Several cellular mechanisms, such as telomere shortening and abnormal expression of mitogenic oncogenes, have been shown to cause senescence. Senescence is not restricted to normal cells; cancer cells have also been reported to senesce.
	Chemotherapeutical drugs have been shown to induce senescence in cancer cells. However, it remains controversial whether senescence prevents or promotes tumorigenesis. As it might eventually be patient-specific, a rapid and sensitive method to assess senescence in cancer cell will soon be required.
	To this end, the standard &beta;-galactosidase assay, the currently used method, presents major drawbacks: it is time consuming and not sensitive. We propose here a flow cytometry-based assay to study senescence on live cells. This assay offers the advantage of being rapid, sensitive, and can be coupled to the immunolabeling of various cellular markers.

Whether senescence prevents or promotes tumorigenesis remains controversial. Since chemotherapeutical drugs can induce cancer cells to senesce, studying senescence is essential for proposing new therapies. However, the standard and broadly used &beta;-galactosidase assay presents major drawbacks. We propose here a rapid and sensitive flow cytometry-based assay to quantify senescence.

Human cells do not indefinitely proliferate. Upon external and/or intrinsic  cues, cells might die or enter a stable cell cycle arrest called senescence. ...

Isolation of Cancer Stem Cells From Human Prostate Cancer Samples

The cancer stem cell (CSC) model has been considerably revisited over the last two decades. During this time CSCs have been identified and directly isolated from human tissues and serially propagated in immunodeficient mice, typically through antibody labeling of subpopulations of cells and fractionation by flow cytometry. However, the unique clinical features of prostate cancer have considerably limited the study of prostate CSCs from fresh human tumor samples. We recently reported the isolation of prostate CSCs directly from human tissues by virtue of their HLA class I (HLAI)-negative phenotype. Prostate cancer cells are harvested from surgical specimens and mechanically dissociated. A cell suspension is generated and labeled with fluorescently conjugated HLAI and stromal antibodies. Subpopulations of HLAI-negative cells are finally isolated using a flow cytometer. The principal limitation of this protocol is the frequently microscopic and multifocal nature of primary cancer in prostatectomy specimens. Nonetheless, isolated live prostate CSCs are suitable for molecular characterization and functional validation by transplantation in immunodeficient mice.

The isolation of cancer stem cells (CSCs) directly from human tissues is requisite for their biological characterization. This manuscript describes a methodology for the isolation of prostate CSCs from human tissues, while also providing tips on troubleshooting difficult steps.

The cancer stem cell (CSC) model has been considerably revisited over the last two decades. During this time CSCs have been identified and directly ...

Two Methods for Establishing Primary Human Endometrial Stromal Cells from Hysterectomy Specimens

Many efforts have been devoted to establish in vitro cell culture systems. These systems are designed to model a vast number of in vivo processes. Cell culture systems arising from human endometrial samples are no exception. Applications range from normal cyclic physiological processes to endometrial pathologies such as gynecological cancers, infectious diseases, and reproductive deficiencies. Here, we provide two methods for establishing primary endometrial stromal cells from surgically resected endometrial hysterectomy specimens. The first method is referred to as &#8220;the scraping method&#8221; and incorporates mechanical scraping using surgical or razor blades whereas the second method is termed &#8220;the trypsin method.&#8221; This latter method uses the enzymatic activity of trypsin to promote the separation of cells and primary cell outgrowth. We illustrate step-by-step methodology through digital images and microscopy. We also provide examples for validating endometrial stromal cell lines via quantitative real time polymerase chain reactions (qPCR) and immunofluorescence (IF).

Establishing primary endometrial stromal cell culture systems from hysterectomy specimens is a valuable biological technique and a crucial step prior to pursuing a vast array of research aims. Here, we describe two methods used to establish stromal cultures from surgically resected endometrial tissues of human patients.&#160;

Many efforts have been devoted to establish in vitro cell culture systems. These systems are designed to model a vast number of in vivo processes. Cell ...

Assessment of Ovarian Cancer Spheroid Attachment and Invasion of Mesothelial Cells in Real Time

Ovarian cancers metastasize by shedding into the peritoneal fluid and dispersing to distal sites within the peritoneum. Monolayer cultures do not accurately model the behaviors of cancer cells within a nonadherent environment, as cancer cells inherently aggregate into multicellular structures which contribute to the metastatic process by attaching to and invading the peritoneal lining to form secondary tumors. To model this important stage of ovarian cancer metastasis, multicellular aggregates, or spheroids, can be generated from established ovarian cancer cell lines maintained under nonadherent conditions. To mimic the peritoneal microenvironment encountered by tumor cells in vivo, a spheroid-mesothelial co-culture model was established in which preformed spheroids are plated on top of a human mesothelial cell monolayer, formed over an extracellular matrix barrier. Methods were then developed using a real-time cell analyzer to conduct quantitative real time measurements of the invasive capacity of different ovarian cancer cell lines grown as spheroids. This approach allows for the continuous measurement of invasion over long periods of time, which has several advantages over traditional endpoint assays and more laborious real time microscopy image analyses. In short, this method enables a rapid, determination of factors which regulate the interactions between ovarian cancer spheroid cells invading through mesothelial and matrix barriers over time.

Ovarian cancer cell invasion into the mesothelial lining of the peritoneum is a dynamic process over time. Utilizing a real time analyzer, the invasive capacity of ovarian cancer cells in a spheroid-mesothelial cell co-culture model can be quantified over prolonged time periods, providing insights into factors regulating the metastatic process.

Ovarian cancers metastasize by shedding into the peritoneal fluid and dispersing to distal sites within the peritoneum. Monolayer cultures do not ...

Murine Model for Non-invasive Imaging to Detect and Monitor Ovarian Cancer Recurrence

Epithelial ovarian cancer is the most lethal gynecologic malignancy in the United States. Although patients initially respond to the current standard of care consisting of surgical debulking and combination chemotherapy consisting of platinum and taxane compounds, almost 90% of patients recur within a few years. In these patients the development of chemoresistant disease limits the efficacy of currently available chemotherapy agents and therefore contributes to the high mortality. To discover novel therapy options that can target recurrent disease, appropriate animal models that closely mimic the clinical profile of patients with recurrent ovarian cancer are required. The challenge in monitoring intra-peritoneal (i.p.) disease limits the use of i.p. models and thus most xenografts are established subcutaneously. We have developed a sensitive optical imaging platform that allows the detection and anatomical location of i.p. tumor mass. The platform includes the use of optical reporters that extend from the visible light range to near infrared, which in combination with 2-dimensional X-ray co-registration can provide anatomical location of molecular signals. Detection is significantly improved by the use of a rotation system that drives the animal to multiple angular positions for 360 degree imaging, allowing the identification of tumors that are not visible in single orientation. This platform provides a unique model to non-invasively monitor tumor growth and evaluate the efficacy of new therapies for the prevention or treatment of recurrent ovarian cancer.

We describe a non-invasive animal imaging platform that allows the detection, quantification, and monitoring of ovarian cancer growth and recurrence. This intra-peritoneal xenograft model mimics the clinical profile of patients with ovarian cancer.

Epithelial ovarian cancer is the most lethal gynecologic malignancy in the United States. Although patients initially respond to the current standard of ...

Enrichment for Chemoresistant Ovarian Cancer Stem Cells from Human Cell Lines

Cancer stem cells (CSCs) are defined as a subset of slow cycling and undifferentiated cells that divide asymmetrically to generate highly proliferative, invasive, and chemoresistant tumor cells. Therefore, CSCs are an attractive population of cells to target therapeutically. CSCs are predicted to contribute to a number of types of malignancies including those in the blood, brain, lung, gastrointestinal tract, prostate, and ovary. Isolating and enriching a tumor cell population for CSCs will enable researchers to study the properties, genetics, and therapeutic response of CSCs. We generated a protocol that reproducibly enriches for ovarian cancer CSCs from ovarian cancer cell lines (SKOV3 and OVCA429). Cell lines are treated with 20 &#181;M cisplatin for 3 days. Surviving cells are isolated and cultured in a serum-free stem cell media containing cytokines and growth factors. We demonstrate an enrichment of these purified CSCs by analyzing the isolated cells for known stem cell markers Oct4, Nanog, and Prom1 (CD133) and cell surface expression of CD177 and CD133. The CSCs exhibit increased chemoresistance. This method for isolation of CSCs is a useful tool for studying the role of CSCs in chemoresistance and tumor relapse.

Cancer stem cells (CSCs) are&#160;implicated in tumor relapse due to chemoresistance. We have optimized a protocol for selection and expansion of CSCs from ovarian cancer cell lines. By treating cells with the chemotherapeutic cisplatin and culturing&#160;in a stem cell promoting media we enrich for non-adherent CSC cultures.

Cancer stem cells (CSCs) are defined as a subset of slow cycling and undifferentiated cells that divide asymmetrically to generate highly proliferative, ...

Quantitative Mass Spectrometric Profiling of Cancer-cell Proteomes Derived From Liquid and Solid Tumors

In-depth analyses of cancer cell proteomes are needed to elucidate oncogenic pathomechanisms, as well as to identify potential drug targets and diagnostic biomarkers. However, methods for quantitative proteomic characterization of patient-derived tumors and in particular their cellular subpopulations are largely lacking. Here we describe an experimental set-up that allows quantitative analysis of proteomes of cancer cell subpopulations derived from either liquid or solid tumors. This is achieved by combining cellular enrichment strategies with quantitative Super-SILAC-based mass spectrometry followed by bioinformatic data analysis. To enrich specific cellular subsets, liquid tumors are first immunophenotyped by flow cytometry followed by FACS-sorting; for solid tumors, laser-capture microdissection is used to purify specific cellular subpopulations. In a second step, proteins are extracted from the purified cells and subsequently combined with a tumor-specific, SILAC-labeled spike-in standard that enables protein quantification. The resulting protein mixture is subjected to either gel electrophoresis or Filter Aided Sample Preparation (FASP) followed by tryptic digestion. Finally, tryptic peptides are analyzed using a hybrid quadrupole-orbitrap mass spectrometer, and the data obtained are processed with bioinformatic software suites including MaxQuant. By means of the workflow presented here, up to 8,000 proteins can be identified and quantified in patient-derived samples, and the resulting protein expression profiles can be compared among patients to identify diagnostic proteomic signatures or potential drug targets.

In-depth analyses of cancer cell proteomes facilitate identification of novel drug targets and diagnostic biomarkers. We describe an experimental workflow for quantitative analysis of (phospho-)proteomes in cancer cell subpopulations derived from liquid and solid tumors. This is achieved by combining cellular enrichment strategies with quantitative Super-SILAC-based mass spectrometry.

In-depth analyses of cancer cell proteomes are needed to elucidate oncogenic pathomechanisms, as well as to identify potential drug targets and diagnostic ...