Nous remercions les membres de notre laboratoire pour leurs discussions utiles et leur soutien. Notre recherche sur les cellules souches du cancer du sein et le microenvironnement tumoral est financée par des subventions de l’Institut de recherche de la Société canadienne de recherche sur le cancer et du U.S. Army Department of Defense Breast Cancer Program (subvention # BC160912). V.B. est soutenu par une bourse postdoctorale Western (Université Western), et A.L.A. et V.B. sont soutenus par la Société du cancer du sein du Canada. C.L. est soutenu par une bourse d’études supérieures du Canada Vanier du gouvernement du Canada.

Les auteurs n’ont rien à divulguer.

Les métastases du cancer du sein et la résistance au traitement sont devenues des causes majeures de mortalité chez les femmes dans le monde entier. L’existence d’une sous-population de cellules souches du cancer du sein (CSBC) contribue à l’augmentation des métastases 26,43,44,45,46 et à la résistance au traitement21,47,48.</sup...

Comprendre les mécanismes cellulaires et moléculaires des cellules souches du cancer du sein humain (CSCA) est crucial pour relever les défis rencontrés dans le traitement du cancer du sein. L’émergence du concept BCSC remonte au début du 21esiècle, où une petite population de cellules cancéreuses du sein CD44 + CD24 / faible s’est avérée capable de générer des tumeurs hétérogènes chez la souris 1,2. Par la suite, il a été observé que les cellules cancéreuses du sein humain ayant une activité enzymatique élevée de l’aldéhyde déshydrogénase (ALDHélevée) présentaient également des propriétés similaires à celles des cellules souches3. Ces BCSC représentent une petite population de cellules capables de s’auto-renouveler et de se différencier, contribuant à la nature hétérogène des tumeurs en vrac 1,2,3. L’accumulation de preuves suggère que les altérations des voies de signalisation conservées au cours de l’évolution déterminent la survie et le maintiende la BCSC 4,5,6,7,8,9,10,11,12,13,14 . En outre, il a été démontré que le microenvironnement extrinsèque cellulaire joue un rôle central dans la dictée des différentes fonctions BCSC15,16,17. Ces voies moléculaires et les facteurs externes régulant la fonction BCSC contribuent à la rechute du cancer du sein, aux métastases18 et au développement d’une résistance aux thérapies 19,20,21, l’existence résiduelle de BCSC post-traitement posant un défi majeur pour la survie globale des patientes atteintes d’un cancer du sein22,23 . L’évaluation préclinique de ces facteurs est donc très importante pour identifier les thérapies ciblant le BCSC qui pourraient être bénéfiques pour obtenir de meilleurs résultats de traitement et améliorer la survie globale chez les patientes atteintes d’un cancer du sein.
Plusieurs modèles in vitro de lignées cellulaires de cancer du sein humain et modèles in vivo de xénogreffes humaines ont été utilisés pour caractériser les CSCA 24,25,26,27,28,29. La capacité des lignées cellulaires à se repeupler continuellement après chaque passage successif en fait un système modèle idéal pour effectuer des études omiques et pharmacogénomiques. Cependant, les lignées cellulaires ne parviennent souvent pas à récapituler l’hétérogénéité observée dans les échantillons de patients. Par conséquent, il est important de compléter les données de lignées cellulaires avec des échantillons dérivés de patients. L’isolement des CSCA dans leur forme la plus pure est important pour permettre une caractérisation détaillée des CSCA. L’atteinte de cette pureté dépend de la sélection de marqueurs phénotypiques spécifiques aux CSBC. Actuellement, le phénotypeALDH à CD44+CD24- élevé est le plus souvent utilisé pour distinguer et isoler les BCSC humaines des populations de cellules cancéreuses du sein en vrac en utilisant le tri cellulaire activé par fluorescence (FACS) pour une pureté maximale1, 3,26. De plus, les propriétés des BCSC isolées, telles que l’auto-renouvellement, la prolifération et la différenciation, peuvent être évaluées à l’aide de techniques in vitro et in vivo.
Par exemple, les essais in vitro formant des colonies peuvent être utilisés pour évaluer la capacité d’une seule cellule à s’auto-renouveler pour former une colonie de 50 cellules ou plus en présence de différentes conditions de traitement30. Les tests de mammosphère peuvent également être utilisés pour évaluer le potentiel d’auto-renouvellement des cellules cancéreuses du sein dans des conditions indépendantes de l’ancrage. Ce test mesure la capacité de cellules individuelles à générer et à se développer sous forme de sphères (mélange de BCSC et de non-BCSC) à chaque passage successif dans des conditions de culture non adhérentes sans sérum31. De plus, des modèles de culture en 3 dimensions (3D) peuvent être utilisés pour évaluer la fonction BCSC, y compris les interactions cellule-cellule et cellule-matrice qui récapitulent étroitement le microenvironnement in vivo et permettent d’étudier l’activité des thérapies potentielles ciblant le BCSC32. Malgré les diverses applications des modèles in vitro, il est difficile de modéliser la complexité des conditions in vivo en utilisant uniquement des essais in vitro. Ce défi peut être surmonté en utilisant des modèles de xénogreffes de souris pour évaluer le comportement de BCSC in vivo. En particulier, ces modèles constituent un système idéal pour évaluer les métastases du cancer du sein33, étudier les interactions avec le microenvironnement au cours de la progression de la maladie 34, l’imagerie in vivo 35 et prédire la toxicité et l’efficacité spécifiques au patient des agents antitumoraux 34.
Ce protocole fournit une description détaillée de l’isolement des BCSC humains à CD44+CD24- élevés en ALDHà unepureté maximale à partir de populations en vrac de cellules hétérogènes du cancer du sein. Nous fournissons également une description détaillée de trois techniques in vitro (test de formation de colonies, test de mammosphère et modèle de culture 3D) et un test de xénogreffe tumorale in vivo qui peut être utilisé pour évaluer différentes fonctions des BCSC. Ces méthodes seraient appropriées pour les chercheurs intéressés à isoler et à caractériser les CSCA à partir de lignées cellulaires de cancer du sein humain ou de cellules cancéreuses du sein et de tissus tumoraux dérivés de patients primaires dans le but de comprendre la biologie du BCSC et/ou d’étudier de nouvelles thérapies ciblant le BCSC.

<table>
	<tbody>
		<tr>
			<td>7-Aminoactinomycin D (7AAD)</td>
			<td>BD</td>
			<td>51-68981E</td>
			<td>suggested: 0.25 &#181;g/1x106 cells</td>
		</tr>
		<tr>
			<td>Acetone</td>
			<td>Fisher</td>
			<td>A18-1</td>
			<td></td>
		</tr>
		<tr>
			<td>Aldehyde dehydrogenase (ALDH) substrate</td>
			<td>Stemcell Technologies</td>
			<td>1700</td>
			<td>Sold commerically as part of the ALDEFLOUR Assay kit; follow manufacturer&#39;s instructions for ALDH substrate preparation</td>
		</tr>
		<tr>
			<td>Basement membrane extract (BME)</td>
			<td>Corning</td>
			<td>354234</td>
			<td>Sold under the commercial name Matrigel</td>
		</tr>
		<tr>
			<td>Cell culture plates: 6 well</td>
			<td>Corning</td>
			<td>877218</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell culture plates: 60mm</td>
			<td>Corning</td>
			<td>353002</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell culture plates: 96-well ultra low attachment</td>
			<td>Corning</td>
			<td>3474</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell strainer: 40 micron</td>
			<td>BD</td>
			<td>352340</td>
			<td></td>
		</tr>
		<tr>
			<td>Collagen</td>
			<td>Stemcell Technologies</td>
			<td>7001</td>
			<td>Prepare 1:30 dilution of 3 mg/mL collagen in PBS</td>
		</tr>
		<tr>
			<td>Collagenase</td>
			<td>Sigma</td>
			<td>11088807001</td>
			<td>1x</td>
		</tr>
		<tr>
			<td>Conical tubes: 50 mL</td>
			<td>Fisher scientific</td>
			<td>05-539-7</td>
			<td></td>
		</tr>
		<tr>
			<td>Crystal violet</td>
			<td>Sigma</td>
			<td>C6158</td>
			<td>Use 0.05% crystal violet solution in water for staining</td>
		</tr>
		<tr>
			<td>Dispase</td>
			<td>Stemcell Technologies</td>
			<td>7913</td>
			<td>5U/mL</td>
		</tr>
		<tr>
			<td>DMEM:F12</td>
			<td>Gibco</td>
			<td>11330-032</td>
			<td>1x, With L-glutamine and 15 mM HEPES</td>
		</tr>
		<tr>
			<td>DNAse</td>
			<td>Sigma</td>
			<td>D5052</td>
			<td>0.1 mg/mL final concentration</td>
		</tr>
		<tr>
			<td>FBS</td>
			<td>Avantor Seradigm Lifescience</td>
			<td>97068-085</td>
			<td>&#160;</td>
		</tr>
		<tr>
			<td>Flow tubes: 5ml</td>
			<td>BD</td>
			<td>352063</td>
			<td>Polypropylene round-bottom tubes</td>
		</tr>
		<tr>
			<td>Methanol</td>
			<td>Fisher</td>
			<td>84124</td>
			<td></td>
		</tr>
		<tr>
			<td>mouse anti-Human CD24 antibody</td>
			<td>BD</td>
			<td>561646</td>
			<td>R-phycoerythrin and Cyanine dye conjugated Clone: ML5</td>
		</tr>
		<tr>
			<td>mouse anti-Human CD44 antibody</td>
			<td>BD</td>
			<td>555479</td>
			<td>R-phycoerythrin conjugated, Clone: G44-26</td>
		</tr>
		<tr>
			<td>N,N-diethylaminobenzaldehyde (DEAB)</td>
			<td>Stemcell Technologies</td>
			<td>1700</td>
			<td>Sold commerically as part of the ALDEFLOUR Assay kit; follow manufacturer&#39;s instructions DEAB preparation</td>
		</tr>
		<tr>
			<td>PBS</td>
			<td>Wisent Inc</td>
			<td>311-425-CL</td>
			<td>1x, Without calcium and magnesium</td>
		</tr>
		<tr>
			<td>Trypsin-EDTA</td>
			<td>Gibco</td>
			<td>25200-056</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Mammosphere Media Composition</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>B27</td>
			<td>Gibco</td>
			<td>17504-44</td>
			<td>1x</td>
		</tr>
		<tr>
			<td>bFGF</td>
			<td>Sigma</td>
			<td>F2006</td>
			<td>10 ng/mL</td>
		</tr>
		<tr>
			<td>BSA</td>
			<td>Bioshop</td>
			<td>ALB003</td>
			<td>04%</td>
		</tr>
		<tr>
			<td>DMEM:F12</td>
			<td>Gibco</td>
			<td>11330-032</td>
			<td>1x, With L-glutamine and 15 mM HEPES</td>
		</tr>
		<tr>
			<td>EGF</td>
			<td>Sigma</td>
			<td>E9644</td>
			<td>20 ng/mL</td>
		</tr>
		<tr>
			<td>Insulin</td>
			<td>Sigma</td>
			<td>16634</td>
			<td>5 &#181;g/mL</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>3D Organoid Media Composition</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>A8301</td>
			<td>Tocris</td>
			<td>2939</td>
			<td>500 nM</td>
		</tr>
		<tr>
			<td>B27</td>
			<td>Gibco</td>
			<td>17504-44</td>
			<td>1x</td>
		</tr>
		<tr>
			<td>DMEM:F12</td>
			<td>Gibco</td>
			<td>11330-032</td>
			<td>1x, With L-glutamine and 15 mM HEPES</td>
		</tr>
		<tr>
			<td>EGF</td>
			<td>Sigma</td>
			<td>E9644</td>
			<td>5 ng/mL</td>
		</tr>
		<tr>
			<td>FGF10</td>
			<td>Peprotech</td>
			<td>100-26</td>
			<td>20 ng/mL</td>
		</tr>
		<tr>
			<td>FGF7</td>
			<td>Peprotech</td>
			<td>100-19</td>
			<td>5 ng/mL</td>
		</tr>
		<tr>
			<td>GlutaMax</td>
			<td>Invitrogen</td>
			<td>35050-061</td>
			<td>1x</td>
		</tr>
		<tr>
			<td>HEPES</td>
			<td>Gibco</td>
			<td>15630-080</td>
			<td>10 mM</td>
		</tr>
		<tr>
			<td>N-acetylcysteine</td>
			<td>Sigma</td>
			<td>A9165</td>
			<td>1.25 mM</td>
		</tr>
		<tr>
			<td>Neuregulin &#946;1</td>
			<td>Peprotech</td>
			<td>100-03</td>
			<td>5 nM</td>
		</tr>
		<tr>
			<td>Nicotinamide</td>
			<td>Sigma</td>
			<td>N0636</td>
			<td>5 mM</td>
		</tr>
		<tr>
			<td>Noggin</td>
			<td>Peprotech</td>
			<td>120-10C</td>
			<td>100 ng/mL</td>
		</tr>
		<tr>
			<td>R-spondin3</td>
			<td>R&#38;D</td>
			<td>3500</td>
			<td>250 ng/mL</td>
		</tr>
		<tr>
			<td>SB202190</td>
			<td>Sigma</td>
			<td>S7067</td>
			<td>500 nM</td>
		</tr>
		<tr>
			<td>Y-27632</td>
			<td>Tocris</td>
			<td>1254</td>
			<td>5 &#181;M</td>
		</tr>
	</tbody>
</table>

isolation and functional assessment of human breast cancer stem cells from cell and tissue samples

Les cellules souches du cancer du sein (CSBC) sont des cellules cancéreuses dont les caractéristiques héréditaires ou acquises ressemblent à des cellules souches. Malgré leur faible fréquence, elles contribuent grandement à l’initiation du cancer du sein, aux rechutes, aux métastases et à la résistance au traitement. Il est impératif de comprendre la biologie des cellules souches du cancer du sein afin d’identifier de nouvelles cibles thérapeutiques pour traiter le cancer du sein. Les cellules souches du cancer du sein sont isolées et caractérisées en fonction de l’expression de marqueurs de surface cellulaire uniques tels que CD44, CD24 et l’activité enzymatique de l’aldéhyde déshydrogénase (ALDH). Ces cellules ALDHà CD44+CD24- élevé constituent la population BCSC et peuvent être isolées par tri cellulaire activé par fluorescence (FACS) pour des études fonctionnelles en aval. Selon la question scientifique, différentes méthodes in vitro et in vivo peuvent être utilisées pour évaluer les caractéristiques fonctionnelles des BCSC. Ici, nous fournissons un protocole expérimental détaillé pour l’isolement des BCSC humains à partir de populations hétérogènes de cellules cancéreuses du sein ainsi que de tissus tumoraux primaires obtenus à partir de patientes atteintes d’un cancer du sein. En outre, nous mettons en évidence des tests fonctionnels in vitro et in vivo en aval, y compris des tests de formation de colonies, des tests de mammosphère, des modèles de culture 3D et des tests de xénogreffe tumorale qui peuvent être utilisés pour évaluer la fonction BCSC.

Le protocole décrit permet d’isoler des CSCA humaines à partir d’une population hétérogène de cellules cancéreuses du sein, soit à partir de lignées cellulaires, soit à partir de tissus tumoraux dissociés. Pour une lignée cellulaire ou un échantillon de tissu donné, il est crucial de générer une suspension unicellulaire uniforme pour isoler les CSCA avec une pureté maximale, car la contamination des populations non BCSC pourrait entraîner des réponses cellulaires variables, en particulier si le but ...

Watch this Scientific Journal Video about Isolation and Functional Assessment of Human Breast Cancer Stem Cells from Cell and Tissue Samples at JoVE.com

Isolation and Functional Assessment of Human Breast Cancer Stem Cells from Cell and Tissue Samples

Ce protocole expérimental décrit l’isolement des CSCA à partir d’échantillons de cellules et de tissus cancéreux du sein ainsi que les tests in vitro et in vivo qui peuvent être utilisés pour évaluer le phénotype et la fonction des CSBC.

Isolement et évaluation fonctionnelle des cellules souches du cancer du sein humain à partir d’échantillons de cellules et de tissus

Breast cancer stem cells (BCSCs) are cancer cells with inherited or acquired stem cell-like characteristics. Despite their low frequency, they are major ...

isolation-functional-assessment-human-breast-cancer-stem-cells-from

Research

JoVE Journal

Cancer Research

4.2K vues.  London Regional Cancer Program. Ce protocole expérimental décrit l’isolement des CSCA à partir d’échantillons de cellules et de tissus cancéreux du sein ainsi que les tests in vitro et in vivo qui peuvent être utilisés pour évaluer le phénotype et la fonction des CSBC.

Vidéo: Isolation and Functional Assessment of Human Breast Cancer Stem Cells from Cell and Tissue Samples

Establishment of Cancer Stem Cell Cultures from Human Conventional Osteosarcoma

The current improvements in therapy against osteosarcoma (OS) have prolonged the lives of cancer patients, but the survival rate of five years remains poor when metastasis has occurred. The Cancer Stem Cell (CSC) theory holds that there is a subset of tumor cells within the tumor that have stem-like characteristics, including the capacity to maintain the tumor and to resist multidrug chemotherapy. Therefore, a better understanding of OS biology and pathogenesis is needed in order to advance the development of targeted therapies to eradicate this particular subset and to reduce morbidity and mortality among patients. Isolating CSCs, establishing cell cultures of CSCs, and studying their biology are important steps to improving our understanding of OS biology and pathogenesis. The establishment of human-derived OS-CSCs from biopsies of OS has been made possible using several methods, including the capacity to create 3-dimensional stem cell cultures under nonadherent conditions. Under these conditions, CSCs are able to create spherical floating colonies formed by daughter stem cells; these colonies are termed &#34;cellular spheres&#34;. Here, we describe a method to establish CSC cultures from primary cell cultures of conventional OS obtained from OS biopsies. We clearly describe the several passages required to isolate and characterize CSCs.

The presence of cancer stem cells (CSCs) in bone sarcomas has recently been linked to their pathogenesis. In this article, we present the isolation of CSCs from primary cell cultures obtained from human biopsies of conventional osteosarcoma (OS) using the ability of CSCs to grow under nonadherent conditions.

Création de souches du cancer de cultures de cellules de Human ostéosarcome conventionnel

The current improvements in therapy against osteosarcoma (OS) have prolonged the lives of cancer patients, but the survival rate of five years remains ...

Recherche

Recherche en cancérologie

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

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

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

Utilisant la génomique fonctionnelle de dépistage pour identifier les cibles de médicaments potentiellement nouveaux dans Cancer Cell Cultures Spheroid

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

Synthesis and Characterization of an Aspirin-fumarate Prodrug that Inhibits NF&#954;B Activity and Breast Cancer Stem Cells

Inflammation is a cancer hallmark that underlies cancer incidence and promotion, and eventually progression to metastasis. Therefore, adding an anti-inflammatory drug to standard cancer regiments may improve patient outcome. One such drug, aspirin (acetylsalicylic acid, ASA), has been explored for cancer chemoprevention and anti-tumor activity. Besides inhibiting the cyclooxygenase 2-prostaglandin axis, ASA&#39;s anti-cancer activities have also been attributed to nuclear factor &#312;B (NF&#312;B) inhibition. Because prolonged ASA use may cause gastrointestinal toxicity, a prodrug strategy has been implemented successfully. In this prodrug design the carboxylic acid of ASA is masked and additional pharmacophores are incorporated.
This protocol describes how we synthesized an aspirin-fumarate prodrug, GTCpFE, and characterized its inhibition of the NF&#312;B pathway in breast cancer cells and attenuation of the cancer stem-like properties, an important NF&#312;B-dependent phenotype. GTCpFE effectively inhibits the NF&#312;B pathway in breast cancer cell lines whereas ASA lacks any inhibitory activity, indicating that adding fumarate to ASA structure significantly contributes to its activity. In addition, GTCpFE shows significant anti-cancer stem cell activity by blocking mammosphere formation and attenuating the cancer stem cell associated CD44+CD24- immunophenotype. These results establish a viable strategy to develop improved anti-inflammatory drugs for chemoprevention and cancer therapy.

Synthesis and Characterization of an Aspirin-fumarate Prodrug that Inhibits NF&amp;#954;B Activity and Breast Cancer Stem Cells

This procedure will demonstrate how we synthesized and characterized the anti-NF&#954;B and anti-cancer stem cell activity of an aspirin-fumarate prodrug.

Synthèse et caractérisation d&#39;un promédicament Aspirin-fumarate qui inhibe l&#39;activité de NFkB et du sein des cellules souches du cancer

Inflammation is a cancer hallmark that underlies cancer incidence and promotion, and eventually progression to metastasis. Therefore, adding an ...

Invasive Behavior of Human Breast Cancer Cells in Embryonic Zebrafish

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

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

Comportement invasif des cellules cancéreuses du sein humain dans Embryonic Zebrafish

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

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

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

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

Débit par cytométrie en flux détection de cellules de cellules souches-comme pour le Cancer du sein nouvellement formé après le renversement de l’apoptose

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

Mesenchymal Stem Cell Isolation from Pulp Tissue and Co-Culture with Cancer Cells to Study Their Interactions

Cancer as a multistep process and complicated disease is not only regulated by individual cell proliferation and growth but also controlled by tumor environment and cell-cell interactions. Identification of cancer and stem cell interactions, including changes in extracellular environment, physical interactions, and secreted factors, might enable the discovery of new therapy options. We combine known co-culture techniques to create a model system for mesenchymal stem cells (MSCs) and cancer cell interactions. In the current study, dental pulp stem cells (DPSCs) and PC-3 prostate cancer cell interactions were examined by direct and indirect co-culture techniques. Condition medium (CM) obtained from DPSCs and 0.4 &#181;m pore sized trans-well membranes were used to study paracrine activity. Co-culture of different cell types together was performed to study direct cell-cell interaction. The results revealed that CM increased cell proliferation and decreased apoptosis in prostate cancer cell cultures. Both CM and trans-well system increased cell migration capacity of PC-3 cells. Cells stained with different membrane dyes were seeded into the same culture vessels, and DPSCs participated in a self-organized structure with PC-3 cells under this direct co-culture condition. Overall, the results indicated that co-culture techniques could be useful for cancer and MSC interactions as a model system.

We provide protocols for evaluation of mesenchymal stem cells isolated from dental pulp and prostate cancer cell interactions based on direct and indirect co-culture methods. Condition medium and trans-well membranes are suitable to analyze indirect paracrine activity. Seeding differentially stained cells together is an appropriate model for direct cell-cell interaction.

Isolement des cellules souches mésenchymateuses du tissu de pulpe et co-culture avec les cellules cancéreuses afin d’étudier leurs Interactions

Cancer as a multistep process and complicated disease is not only regulated by individual cell proliferation and growth but also controlled by tumor ...

Obtaining Cancer Stem Cell Spheres from Gynecological and Breast Cancer Tumors

Cancer stem cells (CSC) are a small population with self-renewal and plasticity which are responsible for tumorigenesis, resistance to treatment and recurrent disease. This population can be identified by surface markers, enzymatic activity and a functional profile. These approaches per se are limited, due to phenotypic heterogeneity and CSC plasticity. Here, we update the sphere-forming protocol to obtain CSC spheres from breast and gynecological cancers, assessing functional properties, CSC markers and protein expression. The spheres are obtained with single-cell seeding at low density in suspension culture, using a semi-solid methylcellulose medium to avoid migration and aggregates. This profitable protocol can be used in cancer cell lines but also in primary tumors. The tridimensional non-adherent suspension culture thought to mimic the tumor microenvironment, particularly the CSC-niche, is supplemented with epidermal growth factor and basic fibroblast growth factor to ensure CSC signaling. Aiming for robust identification of CSC, we propose a complementary approach, combining functional and phenotypic evaluation. Sphere-forming capacity, self-renewal and sphere projection area establish CSC functional properties. Additionally, characterization comprises flow cytometry evaluation of the markers, represented by CD44+/CD24- and CD133, and Western blot, considering ALDH. The presented protocol was also optimized for primary tumor samples, following a sample digestion procedure, useful for translational research.

The aim of this methodology is to identify cancer stem cells (CSC) in cancer cell lines and primary human tumor samples with the sphere-forming protocol, in a robust manner, using functional assays and phenotypic characterization with flow cytometry and Western blot.

Obtenir des sphères de cellules souches cancéreuses à partir de tumeurs gynécologiques et du cancer du sein

Cancer stem cells (CSC) are a small population with self-renewal and plasticity which are responsible for tumorigenesis, resistance to treatment and ...

Isolation of Stem-like Cells from 3-Dimensional Spheroid Cultures

Despite advances in adult stem cell research, identification and isolation of stem cells from tissue specimens remains a major challenge. While resident stem cells are relatively quiescent with niche restraints in adult tissues, they enter the cell cycle in anchor-free three-dimensional (3D) culture and undergo both symmetric and asymmetric cell division, giving rise to both stem and progenitor cells. The latter proliferate rapidly and are the major cell population at various stages of lineage commitment, forming heterogeneous spheroids. Using primary normal human prostate epithelial cells (HPrEC), a spheroid-based, label-retention assay was developed that permits the identification and functional isolation of the spheroid-initiating stem cells at a single cell resolution.
HPrEC or cell lines are two-dimensionally (2D) cultured with BrdU for 10 days to permit its incorporation into the DNA of all dividing cells, including self-renewing stem cells. Wash out commences upon transfer to the 3D culture for 5 days, during which stem cells self-renew through asymmetric division and initiate spheroid formation. While relatively quiescent daughter stem cells retain BrdU-labeled parental DNA, the daughter progenitors rapidly proliferate, losing the BrdU label. BrdU can be substituted with CFSE or Far Red pro-dyes, which permit live stem cell isolation by FACS. Stem cell characteristics are confirmed by in vitro spheroid formation, in vivo tissue regeneration assays, and by documenting their symmetric/asymmetric cell divisions. The isolated label-retaining stem cells can be rigorously interrogated by downstream molecular and biologic studies, including RNA-seq, ChIP-seq, single cell capture, metabolic activity, proteome profiling, immunocytochemistry, organoid formation, and in vivo tissue regeneration. Importantly, this marker-free functional stem cell isolation approach identifies stem-like cells from fresh cancer specimens and cancer cell lines from multiple organs, suggesting wide applicability. It can be used to identify cancer stem-like cell biomarkers, screen pharmaceuticals targeting cancer stem-like cells, and discover novel therapeutic targets in cancers.

Using human primary prostate epithelial cells, we report a novel biomarker-free method of functional characterization of stem-like cells by a spheroid-based label-retention assay. A step-by-step protocol is described for BrdU, CFSE, or Far Red 2D cell labeling; three-dimensional spheroid formation; label-retaining stem-like cell identification by immunocytochemistry; and isolation by FACS.

Isolement des cellules souches des cultures sphéroïdes tridimensionnelles

Despite advances in adult stem cell research, identification and isolation of stem cells from tissue specimens remains a major challenge. While resident ...

Functional Assessment of BRCA1 variants using CRISPR-Mediated Base Editors

Recent studies have investigated the risks associated with BRCA1 gene mutations using various functional assessment methods such as fluorescent reporter assays, embryonic stem cell viability assays, and therapeutic drug-based sensitivity assays. Although they have clarified a lot of BRCA1 variants, these assays involving the use of exogenously expressed BRCA1 variants are associated with overexpression issues and cannot be applied to post-transcriptional regulation. To resolve these limitations, we previously reported a method for functional analysis of BRCA1 variants via CRISPR-mediated cytosine base editor that induce targeted nucleotide substitution in living cells. Using this method, we identified variants whose functions remain ambiguous, including c.-97C&#62;T, c.154C&#62;T, c.3847C&#62;T, c.5056C&#62;T, and c.4986+5G&#62;A, and confirmed that CRISPR-mediated base editors are useful tools for reclassifying the variants of uncertain significance in BRCA1. Here, we describe a protocol for functional analysis of BRCA1 variants using CRISPR-based cytosine base editor. This protocol provides guidelines for the selection of target sites, functional analysis and evaluation of BRCA1 variants.

Functional Assessment of BRCA1 variants using CRISPR-Mediated Base Editors

People with BRCA1 mutations have a higher risk of developing cancer, which warrants accurate evaluation of the function of BRCA1 variants. Herein, we described a protocol for functional assessment of BRCA1 variants using CRISPR-mediated cytosine base editors that enable targeted C:G to T:A conversion in living cells.

Évaluation fonctionnelle des variantes BRCA1 à l’aide d’éditeurs de base à base de CRISPR

Recent studies have investigated the risks associated with BRCA1 gene mutations using various functional assessment methods such as fluorescent reporter ...

Modeling Breast Cancer in Human Breast Tissue using a Microphysiological System

Breast cancer (BC) remains a leading cause of death for women. Despite more than $700 million invested in BC research annually, 97% of candidate BC drugs fail clinical trials. Therefore, new models are needed to improve our understanding of the disease. The NIH Microphysiological Systems (MPS) program was developed to improve the clinical translation of basic science discoveries and promising new therapeutic strategies. Here we present a method for generating MPS for breast cancers (BC-MPS). This model adapts a previously described approach of culturing primary human white adipose tissue (WAT) by sandwiching WAT between adipose-derived stem cell sheets (ASC)s. Novel aspects of our BC-MPS include seeding BC cells into non-diseased human breast tissue (HBT) containing native extracellular matrix, mature adipocytes, resident fibroblasts, and immune cells; and sandwiching the BC-HBT admixture between HBT-derived ASC sheets. The resulting BC-MPS is stable in culture ex vivo for at least 14 days. This model system contains multiple elements of the microenvironment that influence BC including adipocytes, stromal cells, immune cells, and the extracellular matrix. Thus BC-MPS can be used to study the interactions between BC and its microenvironment. 
We demonstrate the advantages of our BC-MPS by studying two BC behaviors known to influence cancer progression and metastasis: 1) BC motility and 2) BC-HBT metabolic crosstalk. While BC motility has previously been demonstrated using intravital imaging, BC-MPS allows for high-resolution time-lapse imaging using fluorescence microscopy over several days. Furthermore, while metabolic crosstalk was previously demonstrated using BC cells and murine pre-adipocytes differentiated into immature adipocytes, our BC-MPS model is the first system to demonstrate this crosstalk between primary human mammary adipocytes and BC cells in vitro.

This protocol describes the construction of an in vitro microphysiological system for studying breast cancer using primary human breast tissue with off the shelf materials.

Modélisation du cancer du sein dans le tissu mammaire humain à l’aide d’un système microphysiologique

Breast cancer (BC) remains a leading cause of death for women. Despite more than $700 million invested in BC research annually, 97% of candidate BC drugs ...