Agradecemos aos membros do nosso laboratório por suas discussões úteis e apoio. Nossa pesquisa sobre células-tronco de câncer de mama e o microambiente tumoral é financiada por doações do Instituto de Pesquisa da Sociedade Canadense de Pesquisa do Câncer e do Programa de Câncer de Mama do Departamento de Defesa do Exército dos EUA (Grant # BC160912). V.B. é apoiado por uma Western Postdoctoral Fellowship (Western University), e tanto a A.L.A. quanto a V.B. são apoiadas pela Breast Cancer Society of Canada. C.L. é apoiado por uma Bolsa de Pós-Graduação Vanier Canada do Governo do Canadá.

Os autores não têm nada a revelar.

A metástase do câncer de mama e a resistência à terapia tornaram-se a principal causa de mortalidade em mulheres em todo o mundo. A existência de uma subpopulação de células-tronco do câncer de mama (CBSCs) contribui para o aumento da metástase 26,43,44,45,46 e da resistência à terapia 21,47,48.<...

Compreender os mecanismos celulares e moleculares das células-tronco do câncer de mama humano (CBSCs) é crucial para enfrentar os desafios encontrados no tratamento do câncer de mama. O surgimento do conceito de CBSC remonta ao início doséculo 21, onde uma pequena população de células CD44+CD24-/baixo câncer de mama foi capaz de gerar tumores heterogêneos em camundongos 1,2. Posteriormente, observou-se que as células de câncer de mama humano com alta atividade enzimática da aldeído desidrogenase (ALDHalta) também apresentaram propriedades semelhantes às células-tronco3. Esses CBSCs representam uma pequena população de células capazes de auto-renovação e diferenciação, contribuindo para a natureza heterogênea dos tumores em massa 1,2,3. Evidências acumuladas sugerem que alterações nas vias de sinalização evolutivamente conservadas impulsionam a sobrevivência e a manutenção do CBSC 4,5,6,7,8,9,10,11,12,13,14 . Além disso, o microambiente extrínseco celular demonstrou desempenhar um papel fundamental na ditadura de diferentes funções do CBSC15,16,17. Essas vias moleculares e os fatores externos que regulam a função do CBSC contribuem para a recidiva do câncer de mama, metástase18 e desenvolvimento de resistência às terapias 19,20,21, sendo que a existência residual de CBSCs pós-tratamento representa um grande desafio para a sobrevida global de pacientes com câncer de mama 22,23 . A avaliação pré-clínica desses fatores é, portanto, muito importante para identificar terapias direcionadas ao BCSC que possam ser benéficas para alcançar melhores resultados de tratamento e melhorar a sobrevida global em pacientes com câncer de mama.
Vários modelos de linhagem celular de câncer de mama humano in vitro e modelos de xenoenxerto humano in vivo têm sido utilizados para caracterizar BCSCs24,25,26,27,28,29. A capacidade das linhagens celulares de repovoar continuamente após cada passagem sucessiva faz delas um sistema modelo ideal para realizar estudos farmacogenômicos e baseados em ômica. No entanto, as linhagens celulares muitas vezes não conseguem recapitular a heterogeneidade observada em amostras de pacientes. Por isso, é importante complementar os dados da linhagem celular com amostras derivadas do paciente. O isolamento de BCSCs em sua forma mais pura é importante para permitir a caracterização detalhada de BCSCs. Alcançar essa pureza depende da seleção de marcadores fenotípicos que são específicos para BCSCs. Atualmente, o fenótipo de células CD44 + CD24- de alta ALDH é mais comumente usado para distinguir e isolar BCSCs humanos de populações de células de câncer de mama em massa usando a classificaçãode células ativadas por fluorescência (FACS) para máxima pureza1, 3,26. Além disso, as propriedades de CBSCs isolados, como auto-renovação, proliferação e diferenciação, podem ser avaliadas usando técnicas in vitro e in vivo.
Por exemplo, ensaios de formação de colônias in vitro podem ser usados para avaliar a capacidade de uma única célula de se auto-renovar para formar uma colônia de 50 células ou mais na presença de diferentes condições de tratamento30. Os ensaios da mamosfera também podem ser usados para avaliar o potencial de auto-renovação das células de câncer de mama sob condições independentes de ancoragem. Este ensaio mede a capacidade de células individuais de gerar e crescer como esferas (mistura de BCSCs e não-BCSCs) a cada passagem sucessiva em condições de cultura não aderente livre de soro31. Além disso, modelos de cultura 3-Dimensional (3D) podem ser usados para avaliar a função do CBSC, incluindo interações célula-célula e célula-matriz que recapitulam de perto o microambiente in vivo e permitem a investigação da atividade de potenciais terapias direcionadas ao BCSC32. Apesar das diversas aplicações de modelos in vitro, é difícil modelar a complexidade de condições in vivo usando apenas ensaios in vitro. Esse desafio pode ser superado pelo uso de modelos de xenoenxerto de camundongos para avaliar o comportamento do CBSC in vivo. Em particular, tais modelos servem como um sistema ideal para avaliar a metástase do câncer de mama33, investigar as interações com o microambiente durante a progressão da doença 34, imagens in vivo 35 e para prever a toxicidade específica do paciente e a eficácia dos agentes antitumorais34.
Este protocolo fornece uma descrição detalhada para o isolamento de ALDH humanos CD44 + CD24-BCSCselevadosna pureza máxima de populações em massa de células heterogêneas de câncer de mama. Também fornecemos uma descrição detalhada de três técnicas in vitro (ensaio de formação de colônias, ensaio de mamosfera e modelo de cultura 3D) e um ensaio de xenoenxerto tumoral in vivo que pode ser usado para avaliar diferentes funções de CBSCs. Esses métodos seriam apropriados para uso por pesquisadores interessados em isolar e caracterizar BCSCs de linhagens celulares de câncer de mama humano ou células de câncer de mama derivadas de pacientes primários e tecido tumoral para fins de compreensão da biologia do BCSC e / ou investigação de novas terapias direcionadas ao 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

As células-tronco do câncer de mama (CBSCs) são células cancerígenas com características hereditárias ou adquiridas semelhantes a células-tronco. Apesar de sua baixa frequência, eles são os principais contribuintes para o início do câncer de mama, recaída, metástase e resistência à terapia. É imperativo entender a biologia das células-tronco do câncer de mama, a fim de identificar novos alvos terapêuticos para tratar o câncer de mama. As células-tronco do câncer de mama são isoladas e caracterizadas com base na expressão de marcadores únicos da superfície celular, como CD44, CD24 e atividade enzimática da aldeído desidrogenase (ALDH). Essas células CD44+CD24-altasde ALDH constituem a população de CBSC e podem ser isoladas por classificação celular ativada por fluorescência (FACS) para estudos funcionais a jusante. Dependendo da questão científica, diferentes métodos in vitro e in vivo podem ser usados para avaliar as características funcionais dos CBSC. Aqui, fornecemos um protocolo experimental detalhado para o isolamento de BCSCs humanos de populações heterogêneas de células de câncer de mama, bem como tecido tumoral primário obtido de pacientes com câncer de mama. Além disso, destacamos ensaios funcionais in vitro e in vivo a jusante, incluindo ensaios de formação de colônias, ensaios de mamosfera, modelos de cultura 3D e ensaios de xenoenxerto tumoral que podem ser usados para avaliar a função do CBSC.

O protocolo descrito permite o isolamento de BCSCs humanos de uma população heterogênea de células de câncer de mama, seja de linhagens celulares ou de tecido tumoral dissociado. Para qualquer linhagem celular ou amostra de tecido, é crucial gerar uma suspensão celular única uniforme para isolar BCSCs na pureza máxima, pois a contaminação de populações não-BCSC pode resultar em respostas celulares variáveis, especialmente se o objetivo do estudo for avaliar a eficácia de agentes terapêuticos direcionados...

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

Este protocolo experimental descreve o isolamento de CBSCs de amostras de células e tecidos de câncer de mama, bem como os ensaios in vitro e in vivo que podem ser usados para avaliar o fenótipo e a função do CBSC.

Isolamento e Avaliação Funcional de Células-Tronco de Câncer de Mama Humano de Amostras de Células e Tecidos

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

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Cancer Research

4.2K visualizações.  London Regional Cancer Program. Este protocolo experimental descreve o isolamento de CBSCs de amostras de células e tecidos de câncer de mama, bem como os ensaios in vitro e in vivo que podem ser usados para avaliar o fenótipo e a função do CBSC.

Vídeo: 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.

Establishment of Cancer Stem Cell Cultures de Human osteossarcoma convencional

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

Pesquisa do câncer

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.

Utilizando Genómica Funcional de triagem para identificar alvos de drogas potencialmente romance em Spheroid culturas de células de câncer

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.

Síntese e Caracterização de um pró-fármaco Aspirina-fumarato que inibe a actividade NFkB e da mama câncer de células estaminais

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.

Comportamento invasiva de células de cancro da mama humano em 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.

Fluxo Cytometric deteção da recém-formada mama câncer células-tronco células após a reversão de 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.

Isolamento de células-tronco mesenquimais de tecido pulpar e co-cultura com células cancerosas para estudar suas interações

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.

Obtenção de esferas de células-tronco cancerígenas de tumores ginecológicos e de câncer de mama

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

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.

Avaliação funcional das variantes BRCA1 usando editores de base mediados pelo 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.

Modelando o câncer de mama no tecido mamário humano usando um sistema microfisiológico

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 ...

A Rapid Screening Workflow to Identify Potential Combination Therapy for GBM using Patient-Derived Glioma Stem Cells

The glioma stem cells (GSCs) are a small fraction of cancer cells which play essential roles in tumor initiation, angiogenesis, and drug resistance in glioblastoma (GBM), the most prevalent and devastating primary brain tumor. The presence of GSCs makes the GBM very refractory to most of individual targeted agents, so high-throughput screening methods are required to identify potential effective combination therapeutics. The protocol describes a simple workflow to enable rapid screening for potential combination therapy with synergistic interaction. The general steps of this workflow consist of establishing luciferase-tagged GSCs, preparing matrigel coated plates, combination drug screening, analyzing, and validating the results.

Um fluxo de trabalho de triagem rápida para identificar terapia de combinação potencial para GBM usando células-tronco glioma derivadas do paciente

The glioma stem cells (GSCs) are a small fraction of cancer cells which play essential roles in tumor initiation, angiogenesis, and drug resistance in ...