Il laboratorio AG è finanziato dal Consiglio spagnolo per la sicurezza nucleare. T.A. e A.G. sono membri di un gruppo di ricerca riconosciuto dalla Generalitat de Catalunya (2017-SGR-503). MT ha un contratto finanziato dalla Fondazione Scientifica Asociación Española Contra el Cáncer [AECC-INVES19022TERR]. Il contratto G.F. è finanziato da una sovvenzione della Fondazione Cellex.

<ol>
	<li>Hanahan, D., Weinberg, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hallmarks+of+cancer:+the+next+generation.">Hallmarks of cancer: the next generation.</a> Cell. 144 (5), 646-674 (2011).</li><li>Stampfer, M. R., Yaswen, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Culture+models+of+human+mammary+epithelial+cell+transformation.">Culture models of human mammary epithelial cell transformation.</a> Journal of Mammary Gland Biology and Neoplasia. 5 (4), 365-378 (2000).</li><li>Schinzel, A. C., Hahn, W. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oncogenic+transformation+and+experimental+models+of+human+cancer.">Oncogenic transformation and experimental models of human cancer.</a> Frontiers in Bioscience : A Journal and Virtual Library. 13 (13), 71 (2008).</li><li>Balani, S., Nguyen, L. V., Eaves, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modeling+the+process+of+human+tumorigenesis.">Modeling the process of human tumorigenesis.</a> Nature Communications. 8 (1), 15422 (2017).</li><li>Bray, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Global+cancer+statistics+2018:+GLOBOCAN+estimates+of+incidence+and+mortality+worldwide+for+36+cancers+in+185+countries.">Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries.</a> CA: A Cancer Journal for Clinicians. 68 (6), 394-424 (2018).</li><li>Ince, T. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transformation+of+different+human+breast+epithelial+cell+types+leads+to+distinct+tumor+phenotypes.">Transformation of different human breast epithelial cell types leads to distinct tumor phenotypes.</a> Cancer Cell. 12 (2), 160-170 (2007).</li><li>Repull&#233;s, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Radiation-induced+malignant+transformation+of+preneoplastic+and+normal+breast+primary+epithelial+cells.">Radiation-induced malignant transformation of preneoplastic and normal breast primary epithelial cells.</a> Molecular Cancer Research. , 1-13 (2019).</li><li>Weigelt, B., Bissell, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unraveling+the+microenvironmental+influences+on+the+normal+mammary+gland+and+breast+cancer.">Unraveling the microenvironmental influences on the normal mammary gland and breast cancer.</a> Seminars in Cancer Biology. 18 (5), 311-321 (2008).</li><li>Paoli, P., Giannoni, E., Chiarugi, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anoikis+molecular+pathways+and+its+role+in+cancer+progression.">Anoikis molecular pathways and its role in cancer progression.</a> Biochimica et Biophysica Acta. 1833 (12), 3481-3498 (2013).</li><li>Debnath, J., Muthuswamy, S. K., Brugge, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morphogenesis+and+oncogenesis+of+MCF-10A+mammary+epithelial+acini+grown+in+three-dimensional+basement+membrane+cultures.">Morphogenesis and oncogenesis of MCF-10A mammary epithelial acini grown in three-dimensional basement membrane cultures.</a> Methods. 30 (3), 256-268 (2003).</li><li>Borowicz, 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=The+soft+agar+colony+formation+assay.">The soft agar colony formation assay.</a> Journal of Visualized Experiments. (92), (2014).</li><li>Schindelin, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fiji:+an+open-source+platform+for+biological-image+analysis.">Fiji: an open-source platform for biological-image analysis.</a> Nature Methods. 9 (7), 676-682 (2012).</li><li>Brocher, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+BioVoxxel+Image+Processing+and+Analysis+Toolbox.">The BioVoxxel Image Processing and Analysis Toolbox.</a> European BioImage Analysis Symposium. 8 (2), 67112 (2015).</li><li>Torquato, S., Truskett, T. M., Debenedetti, P. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Is+random+close+packing+of+spheres+well+defined.">Is random close packing of spheres well defined.</a> Physical Review Letters. 84 (10), 2064-2067 (2000).</li><li>LaBarge, M. A., Garbe, J. C., Stampfer, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Processing+of+human+reduction+mammoplasty+and+mastectomy+tissues+for+cell+culture.">Processing of human reduction mammoplasty and mastectomy tissues for cell culture.</a> Journal of Visualized Experiments. (71), (2013).</li><li>Zubeldia-Plazaola, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glucocorticoids+promote+transition+of+ductal+carcinoma+in+situ+to+invasive+ductal+carcinoma+by+inducing+myoepithelial+cell+apoptosis.">Glucocorticoids promote transition of ductal carcinoma in situ to invasive ductal carcinoma by inducing myoepithelial cell apoptosis.</a> Breast Cancer Research. 20 (1), 65 (2018).</li></ol>

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I protocolli sperimentali descritti in questo documento forniscono strumenti utili per valutare la trasformazione oncogenica delle cellule coltivate in vitro. Ogni tecnica valuta aspetti specifici del processo di trasformazione e, pertanto, occorre prestare particolare attenzione quando si vengono tratte conclusioni da una singola analisi. L'accumulo di curve di crescita è un approccio che richiede informazioni già disponibili quando si coltivano cellule per altri scopi. Ciò rende questa tecnica più economica e più ...

Sono necessari più eventi successivi per lo sviluppo della neoplasia. Nel 2011, Hanahan e Weinberg hanno descritto 10 capacità che consentono la crescita, la sopravvivenza e la diffusione delle cellule trasformate: i cosiddetti "Hallmarks of Cancer"1. La metodologia qui descritta compila tre diversi strumenti per valutare la trasformazione cellulare in vitro concentrandosi su alcune delle caratteristiche distintive delle cellule tumorali. Queste tecniche valutano il tasso di proliferazione cellulare, il comportamento delle cellule quando coltivate in 3D e la loro capacità di formare colonie con indipendenza di ancoraggio.
I modelli cellulari sono fondamentali per testare l'ipotesi in vitro. Diversi approcci sono stati sviluppati per generare modelli sperimentali di trasformazione cellulare per lo studio del cancro2,3,4. Poiché il cancro al seno è il cancro più comune tra le donne in tutto il mondo ed è responsabile di circa il 15% dei decessi per cancrotra le donne 5, fornire modelli cellulari adatti di cellule epiteliali mammarie è della massima importanza per ulteriori indagini. In questo articolo, abbiamo illustrato il potenziale di tre tecniche per valutare la trasformazione cellulare utilizzando un modello sperimentale di trasformazione delle cellule epiteliali primarie del seno (BPEC) inizialmente descritto da Ince e colleghi nel 20076 e successivamente implementato nel nostro laboratorio7. Questo modello sperimentale si basa sull'alterazione sequenziale di tre geni mirati (SV40 Large T e piccoli antigeni t qui indicati come Ttag, hTERTe HRAS) al genoma dei BPEC non trasformati. Inoltre, il metodo utilizzato per la derivazione dei BPEC favorisce il mantenimento di cellule epiteliali mammarie con marcatori luminali o mioepiteliali, risultando in una coltura cellulare eterogenea che conserva alcuni dei tratti fisiologici della ghiandola mammaria.
Nella ghiandola mammaria, le cellule epiteliali mammarie luminali, che sono responsabili della produzione di latte, si trovano vicino al lume, mentre le cellule mioepiteliali vengono smaltite intorno alle cellule luminarie e si prendono cura dei movimenti di contrazione che portano il latte al capezzolo. La perdita di una corretta organizzazione tra questi lignaggi cellulari è una caratteristica dellatrasformazione tumorale 8 che può essere valutata in vitro dopo il rilevamento immunofluorescente di marcatori di lignaggio distintivi nelle colture cellulari 3D. Un'altra caratteristica importante delle cellule tumorali è la loro capacità di crescere senza attaccamento ad altre cellule e alla matrice extracellulare1. Quando le cellule sane sono costrette a crescere in sospensione, meccanismi come anoikis \u2012 un tipo di morte cellulare indotta in risposta al distacco dalla matrice extracellulare \u2012vengono attivati 9. L'evasione della morte cellulare è uno dei tratti distintivi del cancro e quindi, le cellule trasformate sono in grado di inattivare l'anoikis e sopravvivere in modo indipendente dall'ancora. Questa capacità può essere valutata in vitro con il saggio indipendente dall'ancoraggio utilizzando l'agar morbido. Inoltre, una caratteristica intrinseca dei tessuti tumorali è la loro capacità di segnalazione proliferativa sostenuta, che può essere facilmente monitorata in condizioni in vitro misurando l'aumento del numero di cellule nel tempo, non solo nei test di sospensione ma anche monitorando il tasso di crescita delle colture aderenti monostrato.
Nonostante il miglior modello per testare il potenziale tumorigenico sia l'inoculazione delle cellule tumorali nei modelli murini e la valutazione dello sviluppo tumorale in situ, è importante ridurre al minimo il più possibile il numero di animali impiegati nelle procedure sperimentali. Pertanto, avere test adeguati per valutare la trasformazione in vitro è una priorità assoluta. Qui, forniamo una serie di strumenti per valutare il potenziale tumorigenico delle cellule epiteliali del seno parzialmente e completamente trasformate che possono essere facilmente implementate nella maggior parte dei laboratori che lavorano con modelli di trasformazione cellulare.

<table>
	<tbody>
		<tr>
			<td>1 ml Serological Pipettes</td>
			<td>Labclinics</td>
			<td>PLC91001</td>
			<td></td>
		</tr>
		<tr>
			<td>1.5 ml Eppendorfs</td>
			<td>Thermo Fisher Scientific</td>
			<td>3451</td>
			<td>Dark eppendorfs are preferred for MTT long-term storage</td>
		</tr>
		<tr>
			<td>10 &#956;l Pipette tips w/o filter</td>
			<td>Biologix</td>
			<td>20-0010</td>
			<td></td>
		</tr>
		<tr>
			<td>100 ml glass bottle</td>
			<td></td>
			<td></td>
			<td>With cap, autoclavable</td>
		</tr>
		<tr>
			<td>1000 &#956;l Pipette tips w/ filter</td>
			<td>Labclinics</td>
			<td>LAB1000ULFNL</td>
			<td></td>
		</tr>
		<tr>
			<td>1000 &#956;l Pipette tips w/o filter</td>
			<td>Biologix</td>
			<td>20-1000</td>
			<td></td>
		</tr>
		<tr>
			<td>15 ml Conical tubes</td>
			<td>VWR</td>
			<td>525-0400</td>
			<td></td>
		</tr>
		<tr>
			<td>2 ml Serological Pipettes</td>
			<td>Labclinics</td>
			<td>PLC91002</td>
			<td></td>
		</tr>
		<tr>
			<td>200 &#956;l Pipette tips w/ filter</td>
			<td>Labclinics</td>
			<td>FTR200-96</td>
			<td></td>
		</tr>
		<tr>
			<td>5 ml Serological Pipettes</td>
			<td>Labclinics</td>
			<td>PLC91005</td>
			<td></td>
		</tr>
		<tr>
			<td>50 ml Conical Tubes</td>
			<td>VWR</td>
			<td>525-0304</td>
			<td></td>
		</tr>
		<tr>
			<td>Acetone</td>
			<td>PanReac AppliChem</td>
			<td>211007</td>
			<td>Used for 3D structure fixation prior to immunofluorescent labelling</td>
		</tr>
		<tr>
			<td>Agar</td>
			<td>Sigma-Aldrich</td>
			<td>A1296</td>
			<td>Used for anchorage assay</td>
		</tr>
		<tr>
			<td>Anti-Claudin 4 antibody</td>
			<td>Abcam</td>
			<td>15104, RRID:AB_301650</td>
			<td>Working dilution 1:100, host: rabbit</td>
		</tr>
		<tr>
			<td>Anti-Cytokeratin 14 [RCK107] antibody</td>
			<td>Abcam</td>
			<td>9220, RRID:AB_307087</td>
			<td>Working dilution 1:100, host: mouse</td>
		</tr>
		<tr>
			<td>Anti-mouse Cyanine Cy3 antibody</td>
			<td>Jackson ImmunoResearch Inc.</td>
			<td>115-165-146, RRID:AB_2338690</td>
			<td>Working dilution 1:500, host: goat</td>
		</tr>
		<tr>
			<td>Anti-rabbit Alexa Fluor 488 antibody</td>
			<td>Thermo Fisher Scientific</td>
			<td>A-11034, RRID:AB_2576217</td>
			<td>Working dilution 1:500, host: goat</td>
		</tr>
		<tr>
			<td>Autoclave</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>BioVoxxel Toolbox</td>
			<td></td>
			<td>RRID:SCR_015825</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell culture 24-well Plate</td>
			<td>Labclinics</td>
			<td>PLC30024</td>
			<td>Used for 3D cultures in Matrigel. Flat Bottom</td>
		</tr>
		<tr>
			<td>Cell culture 6-well Plate</td>
			<td>Labclinics</td>
			<td>PLC30006</td>
			<td>Used for anchorage assay</td>
		</tr>
		<tr>
			<td>Cell incubator (37 &#186;C and 5 % CO2)</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Cell Strainers</td>
			<td>Fisherbrand</td>
			<td>11587522</td>
			<td>Mesh size: 40 &#956;m</td>
		</tr>
		<tr>
			<td>CellSense software</td>
			<td>Olympus</td>
			<td></td>
			<td>Used to image acquisition</td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Cholera Toxin from Vibrio cholerae</td>
			<td>Sigma-Aldrich</td>
			<td>C8052</td>
			<td>Used to supplement cell culture medium</td>
		</tr>
		<tr>
			<td>Class II Biological Safety Cabinet</td>
			<td>Herasafe</td>
			<td>HAEREUS HS12</td>
			<td></td>
		</tr>
		<tr>
			<td>Confocal inverted Microscope</td>
			<td>Leica</td>
			<td>TCS SP5</td>
			<td></td>
		</tr>
		<tr>
			<td>Cover glasses</td>
			<td>Witeg Labortechnik GmbH</td>
			<td>4600122</td>
			<td>22 X 22 mm, thickness 0.13 - 0.17 mm</td>
		</tr>
		<tr>
			<td>DAPI</td>
			<td></td>
			<td></td>
			<td>2-(4-amidinophenyl)-1H -indole-6-carboxamidine</td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum</td>
			<td>Biowest</td>
			<td>S1810</td>
			<td>Used to inactivate trypsine action</td>
		</tr>
		<tr>
			<td>Fiji software (ImageJ)</td>
			<td>National Institutes of Health</td>
			<td>RRID:SCR_002285</td>
			<td>Free download, no license needed</td>
		</tr>
		<tr>
			<td>Glass Pasteur Pipettes</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Glass slides</td>
			<td>Fisherbrand</td>
			<td>11844782</td>
			<td></td>
		</tr>
		<tr>
			<td>Goat Serum</td>
			<td>Biowest</td>
			<td>S2000</td>
			<td>Used for immunofluorescence of 3D structures</td>
		</tr>
		<tr>
			<td>Heat-Resistant Gloves</td>
			<td></td>
			<td></td>
			<td>Used for agar manipulation after autoclave</td>
		</tr>
		<tr>
			<td>Heater bath (37 &#186;C)</td>
			<td></td>
			<td></td>
			<td>Used to temper solutions prior to cell subculture</td>
		</tr>
		<tr>
			<td>Heater bath (42 &#186;C)</td>
			<td></td>
			<td></td>
			<td>Used to keep agar warm</td>
		</tr>
		<tr>
			<td>Heating plate</td>
			<td></td>
			<td></td>
			<td>Used for Matrigel dehydration</td>
		</tr>
		<tr>
			<td>Humid chamber</td>
			<td></td>
			<td></td>
			<td>Used for the incubation of antibodies during immunofluorescence</td>
		</tr>
		<tr>
			<td>Ice</td>
			<td></td>
			<td></td>
			<td>Used during Matrigel manipulation</td>
		</tr>
		<tr>
			<td>Ice-box</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Inverted Optic Microscope</td>
			<td>Olympus</td>
			<td>IX71</td>
			<td></td>
		</tr>
		<tr>
			<td>Matrigel Matrix</td>
			<td>Becton Dickinson</td>
			<td>354234</td>
			<td>Store at -20 &#186;C and keep cold when in use. Referred to as basement membrane matrix</td>
		</tr>
		<tr>
			<td>Methanol</td>
			<td>PanReac AppliChem</td>
			<td>131091</td>
			<td>Used for 3D structure fixation prior to immunofluorescent labelling</td>
		</tr>
		<tr>
			<td>Micropipette</td>
			<td></td>
			<td></td>
			<td>p1000, p200 and p10</td>
		</tr>
		<tr>
			<td>Microsoft Office Excel</td>
			<td>Microsoft</td>
			<td>RRID:SCR_016137</td>
			<td>Used to calculate population doubling and to obtain growth rate equation</td>
		</tr>
		<tr>
			<td>MilliQ water</td>
			<td></td>
			<td></td>
			<td>Referred to as ultrapure water</td>
		</tr>
		<tr>
			<td>Nail Polish</td>
			<td></td>
			<td></td>
			<td>Used to seal samples after mounting</td>
		</tr>
		<tr>
			<td>Parafilm M</td>
			<td>Bemis</td>
			<td>PM-999</td>
			<td>Used to cover antibody solution during incubation</td>
		</tr>
		<tr>
			<td>PBS pH 7.4 (w/o calcium &#38; magnesium)</td>
			<td>Gibco</td>
			<td>10010-056</td>
			<td>Sterile. Used for cell subculture</td>
		</tr>
		<tr>
			<td>PBS tablets</td>
			<td>Sigma-Aldrich</td>
			<td>P4417</td>
			<td>Dilute in milliQ water. No sterility required. Used for immunofluorescence</td>
		</tr>
		<tr>
			<td>Pipette Aid</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Primaria T25 flasks</td>
			<td>Corning</td>
			<td>353808</td>
			<td>Used for BPEC culture</td>
		</tr>
		<tr>
			<td>Scepter Automated Cell Counter</td>
			<td>Millipore</td>
			<td>PHCC20060</td>
			<td>Alternatively, use an haemocytometer</td>
		</tr>
		<tr>
			<td>Scissors</td>
			<td></td>
			<td></td>
			<td>Used to cut pipette tips and parafilm</td>
		</tr>
		<tr>
			<td>Sterile filters 0.22 &#956;m</td>
			<td>Millipore</td>
			<td>SLGP033RS</td>
			<td>Used to filter MTT solution</td>
		</tr>
		<tr>
			<td>Thiazolyl Blue Tetrazolium Bromide (MTT)</td>
			<td>Sigma-Aldrich</td>
			<td>M2128</td>
			<td>Store at -20 &#186;C</td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Sigma-Aldrich</td>
			<td>T8787</td>
			<td>Used for immunofluorescence of 3D structures</td>
		</tr>
		<tr>
			<td>Trypsin-EDTA 10X</td>
			<td>Biowest</td>
			<td>X0930</td>
			<td>Dilute in PBS to obtain 3X solution</td>
		</tr>
		<tr>
			<td>Vectashield Antifade Mounting Medium</td>
			<td>Vector Laboratories</td>
			<td>H-1000</td>
			<td></td>
		</tr>
		<tr>
			<td>WIT-P-NC Culture Medium</td>
			<td>Stemgent</td>
			<td>00-0051</td>
			<td>Used for primary BPEC culture</td>
		</tr>
		<tr>
			<td>WIT-T Culture Medium</td>
			<td>Stemgent</td>
			<td>00-0047</td>
			<td>Used for transformed BPEC culture</td>
		</tr>
	</tbody>
</table>

in vitro evaluation of oncogenic transformation in human mammary epithelial cells

La tumorigenesi è un processo in più fasi in cui le cellule acquisiscono capacità che consentono la loro crescita, sopravvivenza e diffusione in condizioni ostili. Diversi test cercano di identificare e quantificare questi tratti distintivi delle cellule cancerose; tuttavia, spesso si concentrano su un singolo aspetto della trasformazione cellulare e, di fatto, sono necessari più test per la loro corretta caratterizzazione. Lo scopo di questo lavoro è quello di fornire ai ricercatori una serie di strumenti per valutare la trasformazione cellulare in vitro da un'ampia prospettiva, consentendo così di trarre conclusioni valide.
Un'attivazione prolungata della segnalazione proliferativa è la caratteristica principale dei tessuti tumorali e può essere facilmente monitorata in condizioni in vitro calcolando il numero di raddoppi della popolazione raggiunti nel tempo. Inoltre, la crescita delle cellule nelle colture 3D consente la loro interazione con le cellule circostanti, simile a ciò che accade in vivo. Ciò consente la valutazione dell'aggregazione cellulare e, insieme all'etichettatura immunofluorescente di marcatori cellulari distintivi, di ottenere informazioni su un'altra caratteristica rilevante della trasformazione tumorale: la perdita di una corretta organizzazione. Un'altra caratteristica notevole delle cellule trasformate è la loro capacità di crescere senza attaccamento ad altre cellule e alla matrice extracellulare, che può essere valutata con il saggio di ancoraggio.
Vengono fornite procedure sperimentali dettagliate per valutare il tasso di crescita cellulare, per eseguire l'etichettatura immunofluorescente dei marcatori di lignaggio cellulare nelle colture 3D e per testare la crescita delle cellule indipendenti dall'ancoraggio nell'agar morbido. Queste metodologie sono ottimizzate per le cellule epiteliali primarie del seno (BPEC) a causa della sua rilevanza nel cancro al seno; tuttavia, le procedure possono essere applicate ad altri tipi di celle dopo alcune regolazioni.

Un modello sperimentale di trasformazione cellulare con l'introduzione di tre elementi genetici nei BPEC è stato scelto per generare risultati rappresentativi della trasformazione oncogenica6,7 (Figura 3). I BPEC non trasformati(N)sono stati derivati da tessuti mammari indenne da malattie come descritto dall'Incee dai colleghi 6 e coltivati secondo il protocollo qui indicato. Dopo av...

Watch this Scientific Journal Video about In Vitro Evaluation of Oncogenic Transformation in Human Mammary Epithelial Cells at JoVE.com

In Vitro Evaluation of Oncogenic Transformation in Human Mammary Epithelial Cells

Questo protocollo fornisce strumenti sperimentali in vitro per valutare la trasformazione delle cellule mammarie umane. Vengono descritti i passaggi dettagliati per seguire il tasso di proliferazione cellulare, la capacità di crescita indipendente dall'ancoraggio e la distribuzione di lignaggi cellulari in colture 3D con matrice di membrana basale.

Valutazione in vitro della trasformazione oncogenica nelle cellule epiteliali mammarie umane

Tumorigenesis is a multi-step process in which cells acquire capabilities&#160;that allow their growth, survival, and dissemination under hostile ...

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Research

JoVE Journal

Cancer Research

4.4K Views.  Universitat Autònoma de Barcelona. Questo protocollo fornisce strumenti sperimentali in vitro per valutare la trasformazione delle cellule mammarie umane. Vengono descritti i passaggi dettagliati per seguire il tasso di proliferazione cellulare, la capacità di crescita indipendente dall'ancoraggio e la distribuzione di lignaggi cellulari in colture 3D con matrice di membrana basale.

Video: In Vitro Evaluation of Oncogenic Transformation in Human Mammary Epithelial Cells

Sectioning Mammary Gland Whole Mounts for Lesion Identification

Normal mammary gland development may be altered by exposure to environmental toxicants and pharmaceutical products, excessive exposure to hormones, and genetic alterations. Mammary gland whole mounts are an inexpensive method to capture the progression of morphological changes that may arise after exposure. However, in later life, when abnormalities are more prone to develop, sole reliance on this one method may not always provide enough information to make a proper diagnosis of the abnormality. Historically, in chemical test guideline studies, a single mammary gland is removed at necropsy and prepared as a hematoxylin and eosin (H&#38;E)-stained section. The incorporation of contralateral mammary whole-mount collection and analysis decreases the likelihood of a false-negative assessment. Evaluation of the whole mount is limited by the presence of one or two entire mammary glands on a slide, and in some cases, the abnormalities observed in the whole mount are not uniformly represented in the H&#38;E section.&#160; The goal of this study was to develop a protocol for converting coverslipped mammary whole mounts to H&#38;E-stained sections so that lesions that would otherwise have been missed or that are difficult to diagnose can be identified. Here, we detail a method to produce a high-quality, paraffin-embedded H&#38;E section from a mammary gland that was initially prepared as a whole mount. In comparison to a tissue that was intentionally prepared for H&#38;E sectioning, the whole mount requires additional preparation for tissue removal and processing. However, this method is considered inexpensive, as it requires common lab reagents and little additional time. As a result, this method can provide invaluable information on how chemical and environmental exposures alter normal mammary development, as well as display changes that occur because of genetic modifications.

We developed a method to successfully remove, process, section, and stain, for histopathological evaluation, mammary tissue that had originally been fixed on slides as whole mounts. This method may promote the collection and evaluation of mammary gland whole mounts in reproductive and developmental test guideline studies.

Sezione delle ghiandole mammarie per tutti gli attacchi per identificazione delle lesioni

Normal mammary gland development may be altered by exposure to environmental toxicants and pharmaceutical products, excessive exposure to hormones, and ...

Ricerca

Ricerca sul cancro

Using CRISPR/Cas9 Gene Editing to Investigate the Oncogenic Activity of Mutant Calreticulin in Cytokine Dependent Hematopoietic Cells

Clustered regularly interspaced short palindromic repeats (CRISPR) is an adaptive immunity system in prokaryotes that has been repurposed by scientists to generate RNA-guided nucleases, such as CRISPR-associated (Cas) 9 for site-specific eukaryotic genome editing. Genome engineering by Cas9 is used to efficiently, easily and robustly modify endogenous genes in many biomedically-relevant mammalian cell lines and organisms. Here we show an example of how to utilize the CRISPR/Cas9 methodology to understand the biological function of specific genetic mutations. We model calreticulin (CALR) mutations in murine interleukin-3 (mIL-3) dependent pro-B (Ba/F3) cells by delivery of single guide RNAs (sgRNAs) targeting the endogenous Calr locus in the specific region where insertion and/or deletion (indel) CALR mutations occur in patients with myeloproliferative neoplasms (MPN), a type of blood cancer. The sgRNAs create double strand breaks (DSBs) in the targeted region that are repaired by non-homologous end joining (NHEJ) to give indels of various sizes. We then employ the standard Ba/F3 cellular transformation assay to understand the effect of physiological level expression of Calr mutations on hematopoietic cellular transformation. This approach can be applied to other genes to study their biological function in various mammalian cell lines.

Targeted gene editing using CRISPR/Cas9 has greatly facilitated the understanding of the biological functions of genes. Here, we utilize the CRISPR/Cas9 methodology to model calreticulin mutations in cytokine-dependent hematopoietic cells in order to study their oncogenic activity.

Utilizzando CRISPR/Cas9 Gene Editing per studiare l'attività oncogena di calreticulina mutante in cellule ematopoietiche Cytokine dipendente

Clustered regularly interspaced short palindromic repeats (CRISPR) is an adaptive immunity system in prokaryotes that has been repurposed by scientists to ...

In Vitro Tumor Cell Rechallenge For Predictive Evaluation of Chimeric Antigen Receptor T Cell Antitumor Function

The field of chimeric antigen receptor (CAR) T cell therapy is rapidly advancing with improvements in CAR design, gene-engineering approaches and manufacturing optimizations. One challenge for these development efforts, however, has been the establishment of in vitro assays that can robustly inform selection of the optimal CAR T cell products for in vivo therapeutic success. Standard in vitro tumor-lysis assays often fail to reflect the true antitumor potential of the CAR T cells due to the relatively short co-culture time and high T cell to tumor ratio. Here, we describe an in vitro co-culture method to evaluate CAR T cell recursive killing potential at high tumor cell loads. In this assay, long-term cytotoxic function and proliferative capacity of CAR T cells is examined in vitro over 7 days with additional tumor targets administered to the co-culture every other day. This assay can be coupled with profiling T cell activation, exhaustion and memory phenotypes. Using this assay, we have successfully distinguished the functional and phenotypic differences between CD4+ and CD8+ CAR T cells against glioblastoma (GBM) cells, reflecting their differential in vivo antitumor activity in orthotopic xenograft models. This method provides a facile approach to assess CAR T cell potency and to elucidate the functional variations across different CAR T cell products.

Here, we describe an in vitro co-culture method to recursively challenge tumor-targeted T cells, which allows for phenotypic and functional analysis of antitumor T cell activity.

In Vitro del tumore delle cellule Rechallenge per valutazione predittiva della funzione antitumorale chimerico antigene recettore delle cellule T

The field of chimeric antigen receptor (CAR) T cell therapy is rapidly advancing with improvements in CAR design, gene-engineering approaches and ...

Time-Lapse 2D Imaging of Phagocytic Activity in M1 Macrophage-4T1 Mouse Mammary Carcinoma Cells in Co-cultures

Tumor-associated macrophages (TAMs) have been identified as an important component for tumor growth, invasion, metastasis, and resistance to cancer therapies. However, tumor-associated macrophages can be harmful to the tumor depending on the tumor microenvironment and can reversibly alter their phenotypic characteristics by either antagonizing the cytotoxic activity of immune cells or enhancing anti-tumor response. The molecular actions of macrophages and their interactions with tumor cells (e.g., phagocytosis) have not been extensively studied. Therefore, the interaction between immune cells (M1/M2-subtype TAM) and cancer cells in the tumor microenvironment is now a focus of cancer immunotherapy research. In the present study, a live cell coculture model of induced M1 macrophages and mouse mammary 4T1 carcinoma cells was developed to assess the phagocytic activity of macrophages using a time-lapse video feature using phase-contrast, fluorescent, and differential interference contrast (DIC) microscopy. The present method can observe and document multipoint live-cell imaging of phagocytosis. Phagocytosis of 4T1 cells by M1 macrophages can be observed using fluorescent microscopy before staining 4T1 cells with carboxyfluorescein succinimidyl ester (CFSE). The current publication describes how to coculture macrophages and tumor cells in a single imaging dish, polarize M1 macrophages, and record multipoint events of macrophages engulfing 4T1 cells during 13 h of coculture.

Macrophage phagocytic activity against cancer cells, specifically 4T1 mouse mammary carcinoma cells, was imaged in this study. The live cell coculture model was established and observed using a combination of fluorescent and differential interference contrast microscopy. This assessment was imaged using imaging software to develop multipoint time-lapse video.

Time-Lapse 2D Imaging dell'attività fagocitica in M1 Macrophage-4T1 Mouse Mammary Carcinoma Cells in Co-cultures

Tumor-associated macrophages (TAMs) have been identified as an important component for tumor growth, invasion, metastasis, and resistance to cancer ...

Rat Mammary Epithelial Cell Transplantation into the Interscapular White Fat Pad

As early as the 1970s, researchers have successfully transplanted mammary epithelial cells into the interscapular white fat pad of rats. Grafting mammary epithelium using transplantation techniques takes advantage of the hormonal environment provided by the adolescent rodent host. These studies are ideally suited to explore the impact of various biological manipulations on mammary gland development and dissect many aspects of mammary gland biology. A common, but limiting, feature is that transplanted epithelial cells are strongly influenced by the surrounding stroma and outcompeted by endogenous epithelium; to utilize native mammary tissue, the abdominal-inguinal white fat pad must be cleared to remove host mammary epithelium prior to the transplantation. A major obstacle when using the rat model organism is that clearing the developing mammary tree in post-weaned rats is not efficient. When transplanted into gland-free fat pads, donor epithelial cells can repopulate the cleared host fat pad and form a functional mammary gland. The interscapular fat pad is an alternative location for these grafts. A major advantage is that it lacks ductal structures yet provides the normal stroma that is necessary to promote epithelial outgrowth and is easily accessible in the rat. Another major advantage of this technique is that it is minimally invasive, because it eliminates the need to cauterize and remove the growing endogenous mammary tree. Additionally, the interscapular fat pad contains a medial blood vessel that can be used to separate sites for grafting. Because the endogenous glands remain intact, this technique can also be used for studies comparing the endogenous mammary gland to the transplanted gland. This paper describes the method of mammary epithelial cell transplantation into the interscapular white fat pad of rats.

This article describes a transplantation method to graft donor rat mammary epithelial cells into the interscapular white fat pad of recipient animals. This method can be used to examine host and/or donor effects on mammary epithelium development and eliminates the need for pre-clearing, thereby extending the usefulness of this technique.

Rat mammary Epithelial Cell Transplantation nel Pad Grasso Bianco Interscapular

As early as the 1970s, researchers have successfully transplanted mammary epithelial cells into the interscapular white fat pad of rats. Grafting mammary ...

Evaluation of the In vivo Antitumor Activity of Polyanhydride IL-1&#945; Nanoparticles

Cytokine therapy is a promising immunotherapeutic strategy that can produce robust antitumor immune responses in cancer patients. The proinflammatory cytokine interleukin-1 alpha (IL-1&#945;) has been evaluated as an anticancer agent in several preclinical and clinical studies. However, dose-limiting toxicities, including flu-like symptoms and hypotension, have dampened the enthusiasm for this therapeutic strategy. Polyanhydride nanoparticle (NP)-based delivery of IL-1&#945; would represent an effective approach in this context since this may allow for a slow and controlled release of IL-1&#945; systemically while reducing toxic side effects. Here an analysis of the antitumor activity of IL-1&#945;-loaded polyanhydride NPs in a head and neck squamous cell carcinoma (HNSCC) syngeneic mouse model is described. Murine oropharyngeal epithelial cells stably expressing HPV16 E6/E7 together with hRAS and luciferase (mEERL) cells were injected subcutaneously into the right flank of C57BL/6J mice. Once tumors reached 3-4 mm in any direction, a 1.5% IL-1a - loaded 20:80 1,8-bis(p-carboxyphenoxy)-3,6-dioxaoctane:1,6-bis(p-carboxyphenoxy)hexane (CPTEG: CPH) nanoparticle (IL-1&#945;-NP) formulation was administered to mice intraperitoneally. Tumor size and body weight were continuously measured until tumor size or weight loss reached euthanasia criteria. Blood samples were taken to evaluate antitumor immune responses by submandibular venipuncture, and inflammatory cytokines were measured through cytokine multiplex assays. Tumor and inguinal lymph nodes were resected and homogenized into a single-cell suspension to analyze various immune cells through multicolor flow cytometry. These standard methods will allow investigators to study the antitumor immune response and potential mechanism of immunostimulatory NPs and other immunotherapy agents for cancer treatment.

Evaluation of the In vivo Antitumor Activity of Polyanhydride IL-1&#945; Nanoparticles

A standard protocol is described to study the antitumor activity and associated toxicity of IL-1&#945; in a syngeneic mouse model of HNSCC.

Valutazione dell'attività antitumorale in vivo di nanoparticelle di polianidride IL-1α

Cytokine therapy is a promising immunotherapeutic strategy that can produce robust antitumor immune responses in cancer patients. The proinflammatory ...

Mammary Epithelial and Endothelial Cell Spheroids as a Potential Functional In vitro Model for Breast Cancer Research

Breast cancer is the leading cause of mortality in women. The growth of breast cancer cells and their subsequent metastasis is a key factor for its progression. Although the mechanisms involved in promoting breast cancer growth have been intensively studied using monocultures of breast cancer cells such as MCF-7 cells, the contribution of other cell types, such as vascular and lymphatic endothelial cells that are intimately involved in tumor growth, has not been investigated in depth. Cell-cell interaction plays a key role in tumor growth and progression. Neoangiogenesis, or the development of vessels, is essential for tumor growth, whereas the lymphatic system serves as a portal for cancer cell migration and subsequent metastasis. Recent studies provide evidence that vascular and lymphatic endothelial cells can significantly influence cancer cell growth. These observations imply a need for developing in vitro models that would more realistically reflect breast cancer growth processes in vivo. Moreover, restrictions in animal research require the development of ex vivo models to elucidate better the mechanisms involved.
This article describes the development of breast cancer spheroids composed of both breast cancer cells (estrogen receptor-positive MCF-7 cells) and vascular and/or lymphatic endothelial cells. The protocol describes a detailed step-by-step approach in creating dual-cell spheroids using two different approaches, hanging drop (gold standard and cheap) and 96-well U-bottom plates (expensive). In-depth instructions are provided for how to delicately pick up the formed spheroids to monitor growth by microscopic sizing and assessing viability using dead and live cell staining. Moreover, procedures to fix the spheroids for sectioning and staining with growth-specific antibodies to differentiate growth patterns in spheroids are delineated. Additionally, details for preparing spheroids with transfected cells and methods to extract RNA for molecular analysis are provided. In conclusion, this article provides in-depth instructions for preparing multi-cell spheroids for breast cancer research.

Mammary Epithelial and Endothelial Cell Spheroids as a Potential Functional In vitro Model for Breast Cancer Research

Crosstalk between mammary epithelial cells and endothelial cells importantly contributes to breast cancer progression, tumor growth, and metastasis. In this study, spheroids have been made from breast cancer cells together with vascular and/or lymphatic endothelial cells and demonstrate their applicability as an in vitro system for breast cancer research.

Sferoidi epiteliali ed endoteliali mammari come potenziale modello funzionale in vitro per la ricerca sul cancro al seno

Breast cancer is the leading cause of mortality in women. The growth of breast cancer cells and their subsequent metastasis is a key factor for its ...

Reconstruct Human Retinoblastoma In Vitro

Human RB is pediatric cancer, which is lethal if no treatment is administered. As RB originates from cone precursors, which is relatively rare in rodent models, meanwhile regarding the interspecies differences between humans and rodents, a disease model derived from humans is more beneficial for uncovering the mechanisms of human RB and seeking the targets of therapy. Herein, the protocol describes the generation of two gene-edited hESC lines with a biallelic RB1 point mutation (RB1Mut/Mut) and an RB1 knockout mutation (RB1-/-), respectively. During the process of retinal development, the formation of RB is observed. The RB cell lines are also established by segregating from the RB organoids. Altogether, by differentiating the gene-edited hESC lines into the retinal organoids using a 2D and 3D combined differentiation protocol, we have successfully reconstructed the human RB in a dish and identified its cone-precursor origin. It would provide a helpful disease model for observing the retinoblastoma genesis, proliferation, and growth as well as further developing novel therapeutic agents.

We describe a method for generating human retinoblastoma (RB) by introducing biallelic RB1 mutations in human embryonic stem cells (hESC). RB cell lines could also be successfully cultured using the isolated RB in a dish.

Ricostruire il retinoblastoma umano in vitro

Human RB is pediatric cancer, which is lethal if no treatment is administered. As RB originates from cone precursors, which is relatively rare in rodent ...

Generating and Imaging Mouse and Human Epithelial Organoids from Normal and Tumor Mammary Tissue Without Passaging

Organoids are a reliable method for modeling organ tissue due to their self-organizing properties and retention of function and architecture after propagation from primary tissue or stem cells. This method of organoid generation forgoes single-cell differentiation through multiple passages and instead uses differential centrifugation to isolate mammary epithelial organoids from mechanically and enzymatically dissociated tissues. This protocol provides a streamlined technique for rapidly producing small and large epithelial organoids from both mouse and human mammary tissue in addition to techniques for organoid embedding in collagen and basement extracellular matrix. Furthermore, instructions for in-gel fixation and immunofluorescent staining are provided for the purpose of visualizing organoid morphology and density. These methodologies are suitable for myriad downstream analyses, such as co-culturing with immune cells and ex vivo metastasis modeling via collagen invasion assay. These analyses serve to better elucidate cell-cell behavior and create a more complete understanding of interactions within the tumor microenvironment.

This protocol discusses an approach for generating epithelial organoids from primary normal and tumor mammary tissue through differential centrifugation. Furthermore, instructions are included for three-dimensional culturing as well as immunofluorescent imaging of embedded organoids.

Generazione e imaging di organoidi epiteliali di topo e umani da tessuto mammario normale e tumorale senza passaggio

Organoids are a reliable method for modeling organ tissue due to their self-organizing properties and retention of function and architecture after ...

In Vivo Gene Delivery into Mouse Mammary Epithelial Cells Through Mammary Intraductal Injection

Mouse mammary glands comprise ductal trees, which are lined by epithelial cells and have one opening at the tip of each nipple. The epithelial cells play a major role in mammary gland function and are the origin of most mammary tumors. Introducing genes of interest into mouse mammary epithelial cells is a critical step in evaluating gene function in epithelial cells and generating mouse mammary tumor models. This goal can be accomplished through the intraductal injection of a viral vector carrying the genes of interest into the mouse mammary ductal tree. The injected virus subsequently infects mammary epithelial cells, bringing in the genes of interest. The viral vector can be lentiviral, retroviral, adenoviral, or adenovirus-associated viral (AAV). This study demonstrates how a gene of interest is delivered into mammary epithelial cells through mouse mammary intraductal injection of a viral vector. A lentivirus carrying GFP is used to show stable expression of a delivered gene, and a retrovirus carrying Erbb2 (HER2/Neu) is used to demonstrate oncogene-induced atypical hyperplastic lesions and mammary tumors.

In Vivo Gene Delivery into Mouse Mammary Epithelial Cells Through Mammary Intraductal Injection

The present protocol describes intraductal injection of viral vectors via the teat to deliver genes of interest into the mammary epithelial cells.

In vivo Consegna genica nelle cellule epiteliali mammarie di topo attraverso l'iniezione intraduttale mammaria

Mouse mammary glands comprise ductal trees, which are lined by epithelial cells and have one opening at the tip of each nipple. The epithelial cells play ...