Name: focus formation: a cell-based assay to determine the oncogenic potential of a gene
Uploaded: 2014-12-31T15:00:00.000+00:00
Duration: 8 min 18 s
Description: Watch this Scientific Journal Video about Focus Formation: A Cell-based Assay to Determine the Oncogenic Potential of a Gene at JoVE.com

Bu çalışma NIH Yönetmenin Yeni Yenilikçi Ödülü Programı (ED) bir hibe ile desteklenmiştir. AA Ulusal Kanser Enstitüsü ve Ulusal Bilim Vakfı lisans ödülleri kısmen desteklenmiştir.

1. Viral vektörlerin yapımına İlgi konusu genin, hem de pozitif ve negatif kontroller için kodlama dizileri, geleneksel klonlama (PCR amplifikasyonu, sınırlama sindirimi ve ligasyon) ile pBABEpuro sokulur. BamHI, SnaBI, EcoRI ve SalI: DNA ilave edilebilir vektör üzerindeki dört kısıtlama bölgeleri vardır. <ol><li> QIAGEN plazmit Midi Kit kullanılarak yetkili hücrelerin transfeksiyonu dereceli plazma DNA hazırlanır. </li><li> Bir NanoDrop2000 spektrofotometre kullanılarak DNA konsantrasyonu ölçümü. </li></ol> 2. Retrovirus Üretimi Plat-E, paketleme hücre soyu NIH 3T3 hücreleri ilgilendiren cDNA teslim edecek ekotropik retrovirüs üretmek için kullanılır. <ol><li> Dondurulmuş Hücreleri Plat-e Kültürler kurulması <ol><li> Hızlı bir şekilde 37 ° C su banyosu içinde Plat-E hücreler eritin ve 15 ml konik tüp aktarın. Yavaş yavaş (Du Plat-E orta 9 ml ekleyinlbecco Modifiye Kartal Ortamı (DMEM)% 10 fetal sığır serumu (FBS) + penisilin ve streptomisin). </li><li> 180 x tüp santrifüj g 5 dakika ve süpernatan atılır. </li><li> 10 cm kültür çanak Plat-E orta ve transfer 10 ml hücreleri yeniden askıya. </li><li> Bunlar% 80-90 ortak akışlı (yaklaşık 2 gün) kadar 37 ° C,% 5 CO2 inkübatörü içinde inkübe hücreleri. </li></ol></li><li> Hücre Bölme <ol><li> Orta aspire ve bir kez PBS ile yıkayın hücreleri. </li><li> % 0.05 tripsin-EDTA 2 ml ilave edilir ve oda sıcaklığında 1 dakika boyunca inkübe edin. </li><li> , Dokunarak parmak hücreleri ayırmak Plat-E orta 10 ml ekleyin ve 15 ml tüp hücre süspansiyonu aktarın. </li><li> 180 x tüp santrifüj g 5 dakika ve süpernatan atılır. </li><li> Plat-D ortamı 10 ml hücrelerin yeniden süspanse edin ve 1 yeni yemekler bunları tohum: 4-1: 6 dilüsyonları. </li></ol></li><li> Plat-E Tohumlama ve Transfeksiyon <ol><li> Tohum, 2 x 10 6Herhangi bir antibiyotik olmadan Plat-E ortamı kullanılarak 10 cm kültür çanak başına hücreleri. </li><li> 37 ° C,% 5 CO2 inkübatöründe hücreleri O / N inkübe edin. </li><li> Ertesi gün, her 1.5 ml mikrofüj tüpüne Opti-MEM içinde 300 ul aktarın. </li><li> Opti-MEM ile hazırlanan bir tüpe, polietilenimin 27 ul (PEI), düşük maliyetli bir transfeksiyon ayıracı 12 ekleyin. Dokunarak parmakla hafifçe karıştırın ve oda sıcaklığında 5 dakika inkübe edilir. </li><li> Opti-MEM / PEI tüp içine transfeksiyon dereceli plazmid DNA 9 ug ekle vorteks ile yavaşça karıştırın ve 15 dakika oda sıcaklığında inkübe edin. </li><li> Ekle DNA / PEI Plat-E kabına ve 37 ° C&#39;de O / N inkübe karmaşık bilge damla,% 5 CO 2. </li><li> Bir sonraki gün, transfeksiyon reaktifi ihtiva eden bir ortam aspire ve (antibiyotikler olmadan) taze Plat-D ortamı 10 ml ekleyin. </li><li> Inkübatör hücreleri dönün. </li></ol></li></ol> 3. NIH 3T3 hücreleri ve Enfeksiyon <ol><li> NIH kurulması3T3 Kültürleri ve Tohumculuk <ol><li> Hızlı bir şekilde 37 ° C su banyosu içinde, NIH 3T3 hücrelerini eritin ve 15 ml&#39;lik bir tüpe transfer. Yavaş yavaş NIH 3T3 ortamında (DMEM +% 10 FBS) 9 ml ekleyin. </li><li> 180 x tüp santrifüj g 5 dakika ve süpernatan atılır. </li><li> 10 cm&#39;lik bir kültür tabağına, NIH 3T3, orta ve devir, 10 ml ile tekrar süspansiyon hücreleri. </li><li> 37 ° C,% 5 CO2 inkübatörü içinde inkübe hücreleri. Bu kendiliğinden dönüşüm (ve odak oluşumu bu nedenle, bazal seviye) sıklığı gibi bir kültür konfluent ulaştıktan sonra artar, NIH 3T3 hücreleri, her zaman underconfluent (% 50-60) tutulması çok önemlidir. </li><li> 10 cm çanak başına tohum 3 x 10 5 hücreleri ve ertesi gün enfeksiyonu için O / N kuluçkaya yatmaktadır. </li></ol></li><li> Enfeksiyon <ol><li> 0.45 um gözenek boyutlu naylon zar filtre boyunca, 10 ml&#39;lik atılabilir bir şırınga kullanılarak, ve 15 ml aktararak Plat-E, çanak retroviral süpernatan hasattüp. </li><li> (Antibiyotikler olmadan) hücrelere taze Plat-E orta 10 ml ekleyin ve inkübatör onları geri. </li><li> Enfekte NIH 3T3 hücre çanak orta aspire ve virüs ihtiva eden, süzüldü süpernatanın 5 normal NIH 3T3 ortamının ml ve 5 mi ekleyin. </li><li> 6 ug / ml&#39;lik bir konsantrasyonda çanak polybrene ekleyin. </li><li> 37 ° C&#39;de,% 5 CO2 hücreleri O / N inkübe edin. </li><li> Enfeksiyon ikinci tur için 3.2.5 - Ertesi gün, tekrar 3.2.1 adımları. </li><li> Normal NIH 3T3 ortamı ile virüs içeren ortam değiştirin. </li><li> Gerektiğinde ortamının değiştirilmesiyle, NIH 3T3 hücreleri, 2-3 hafta boyunca büyümeye izin verin. Çoğaltma plakalarından bütün hücre lizatları üzerindeki geleneksel protein elektroforezi ve immüno-lekeleme ile, ilgilenilen proteinin ekspresyonunu kontrol edin. </li></ol></li></ol> 4. Boyama ve miktarının belirlenmesi <ol><li> Kristal Violet Boyama <ol><li> NIH 3T3 orta aspire ve yemekler yerBuz üzerinde. </li><li> Buz soğukluğunda PBS ile iki kez yemekler yıkayın. </li><li> 10 dakika boyunca buz soğukluğunda metanol ile hücreleri saptamak. </li><li> Buz yemekler çıkarın metanol havalandırın, ve 25% metanol (RT) &#39;de yapılan% 0.5 kristal mor çözelti 3 ml ekleyin. </li><li> Oda sıcaklığında 5 dakika boyunca yemekler inkübe edin. </li><li> Kristal viyole çözüm aspire ve hiçbir renk durulama kapalı gelene kadar dikkatli Milli-Q H 2 O ile çanak durulayın. </li><li> Yemekleri masa üstü Ç / N kurumasını bekleyin (ortaya). </li></ol></li><li> Foci Kantifikasyon <ol><li> Yemekler, kuru, plaka üzerinde hücrelerin koyu renkli koleksiyonlarını ölçmek için bir cetvel kullanın. Sadece olarak çapı 5 mm&#39;nin olanlar saymak &quot;odaklar.&quot; Odaklarının sayısını kaydedin ve ortalamalar ve kontrollere göre önemini hesaplamak. </li></ol></li></ol>

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Yazarlar ifşa hiçbir şey yok.

FFA in vitro malign transformasyon değerlendirmek için hızlı ve kolay bir yöntem sağlar. Aday genler nispeten büyük sayıda taranması için uygundur ve mütevazı teknik gereksinimler, maliyet açısından tercih. Bundan başka, iki ya da daha çok gen birlikte eksprese edilebilir kombinasyonunun tümörijenik potansiyelini değerlendirmek için (bazen &quot;işbirliği&quot; deneyi olarak da adlandırılır). Bu testin avantajları basit tekniği, miktar kolaylığı ve nispeten kısa dönüş etrafı...

Tümör hücrelerinin gen ifadesi örnekleri morfolojik ve proliferatif değişikliklere epigenomics için, değişiklik geniş bir yelpazesi ile, bunların normal emsallerine ayırt edilebilir. Sonuncular içinde, sonuç olarak, hayvanlara enjekte edildiğinde tümör oluşturma yeteneği habis dönüşüm 3 yararlı ölçülebilir göstergeleri, serum bağımlılığı, kontak (yoğunluğu) inhibisyonu kaybı, ankoraj-bağımsız çoğalma satın azalır ve. In vitro ve in vivo tahliller çeşitli hücresel transformasyon için geliştirilmiştir. In vitro deneyler, amaç (düşük serumda büyümesi) belirlenmesi ve kültür morfolojisi (odak oluşumu testi), kültür dinamiği (büyüme oranı, doygunluk yoğunluk) ve büyüme faktörü değişiklikleri ölçülmesi veya gereksinimleri ankraj (yumuşak agar büyüme). Bir hücre tipi malign tabiatını tespit etmek için altın standart deney hayvanlarında tümör formasyonu (ksenogrefleri) kalır. Bununla birlikte, TO mal ve in vivo çalışmalar uzunluğu her zaman aday onkojenlerin ilk doğrulama adımı veya tarama gibi onları haklı yapmazlar. Hiçbir in vitro deney, bir genin onkojenik potansiyeli kesin bir değerlendirmesini sağlar rağmen, onlar in vivo çalışmalar geleceği daraltmak olabilir onkojenik potansiyeli içgörü sağlarlar. In vitro onkojenik potansiyeli değerlendirmek için en yaygın kullanılan sistemlerden biri Odak Oluşumu Testi 2. Bu yaklaşım, NIH 3T3 fare fibroblast, mutlaka temas inhibisyonu gösteren bir dönüştürülmemiş hücre çizgisinin kullanımına dayanır. Yoğunluk bağımlı büyüme kaybına bir onkogen sonuçların aşırı ekspresyonu; Dönüştürülen hücreler daha sonra kolayca dönüştürülmemiş hücrelerin arka plan tek tabaka ile görselleştirildi &quot;odak&quot; oluşturan, çok sayıda tabaka halinde büyüyebilir. İletişim inhib kaybı ile kanıtlandığı gibi odak oluşumu Deneyi, daha sonra, habis dönüşümünün uyarılması için aday onkogen kabiliyetini ölçmektedirölçülebilir fenotip olarak yerleştirme. FFA (örneğin, Src 4 BRAF 5), protein kinazların aşırı ekspresyonu, transkripsiyon faktörleri (örneğin, N-myc 6) (örneğin, P2RY8 7), G-protein bağlı reseptörler ve GTPazlar (örneğin, dönüşümün değerlendirmek için kullanılmıştır Ras 1), ve diğerleri. Bu deneyde göreli kolaylığı genin ekspresyonu in vitro NIH 3T3 fare fibroblast hücrelerini dönüştürmek için yeterli olup olmadığı hızlı ve görsel net bir cevap verecek iyi bir seçim yapar. Bu protokol açıklanan FFA viral ambalaj proteinleri sağlar Plat-E ambalaj hücre hattı 8, kullanır ve retroviral vektörü pBABEpuro 9 (Addgene plazmid 1764) retrovirüs üretmek. İlgi konusu geni içeren pBABEpuro yapısı ile transfeksiyondan sonra Plat-D hücre çizgisi NIH 3T3 hücreleri enfekte etmek için kullanılabilir ekotropik retrovirüs üretecektir. TGen teslim onun viral yöntem, geleneksel kimyasal transfeksiyon yöntemlere göre daha etkili olduğunu ve sürdürülebilir geni 10 ifade etmek için bir yol sunar. Bir kez NIH 3T3 hücrelerinin genomu içine dahil edilmiş, ilgi konusu genin aşın virüs uzun terminal tekrarları (LTR) promoteri 11 tarafından tahrik edilir. Bu sabit ifade eden NIH 3T3 hücreleri üzerinde odaklarının oluşumu ile ölçüldüğü haliyle ilgi konusu genin onkojenik etkinliğe sahip olup olmadığını belirlemek için kullanılabilir.

<table><tbody><tr><td>pBABE-puro vector</td><td>Addgene</td><td>Plasmid 1764</td><td>cloning vector</td></tr><tr><td>Platinum-E Retroviral Packaging Cell Line, Ecotropic</td><td>Cell Biolabs, Inc.</td><td>RV-101</td><td>cell line for viral production</td></tr><tr><td>NIH 3T3 Cell Line murine</td><td>Sigma-Aldrich</td><td>93061524</td><td>cell line for focus formation assay</td></tr><tr><td>10 ml BD Luer-Lok tip syringe</td><td>BD Biosciences</td><td>309604</td><td>viral production reagent</td></tr><tr><td>0.45 &amp;mu;m Puradisc Syringe Filter</td><td>Whatman</td><td>6750-2504</td><td>viral production reagent</td></tr><tr><td>Polyethylenimine (PEI)</td><td>Polysciences, Inc.</td><td>23966-2</td><td>cell transfection reagent</td></tr><tr><td>Polybrene Infection / Transfection Reagent</td><td>EMD Millipore</td><td>TR-1003-G</td><td>cell transfection reagent</td></tr><tr><td>Crystal Violet</td><td>Fisher Scientific</td><td>C581-25</td><td>cell stain reagent</td></tr><tr><td>Plasmid Plus Midi Kit</td><td>QIAGEN</td><td>12945</td><td>plasmid purification</td></tr><tr><td>BD Falcon Tissue Culture Dishes</td><td>BD Biosciences</td><td>353003</td><td>cell culture supplies</td></tr><tr><td>Dulbecco&#039;s Modified Eagle Medium (DMEM)</td><td>Gibco</td><td>11995-065</td><td>cell culture media</td></tr><tr><td>0.05% Trypsin-EDTA</td><td>Gibco</td><td>25300-054</td><td>cell culture supplies</td></tr><tr><td>Opti-MEM I Reduced Serum Medium</td><td>Gibco</td><td>31985-062</td><td>cell culture media</td></tr><tr><td>Fetal Bovine Serum (FBS)</td><td>Gibco</td><td>16000-044</td><td>cell culture media</td></tr></tbody></table>

focus formation: a cell-based assay to determine the oncogenic potential of a gene

Malignant transformation of cells is typically associated with increased proliferation, loss of contact inhibition, acquisition of anchorage-independent growth potential, and the ability to form tumors in experimental animals1. In NIH 3T3 cells, the Ras signal transduction pathway is known to trigger many of these events, what is known as Ras transformation. The introduction of an overexpressed gene in NIH 3T3 cells may promote morphological transformation and loss of contact inhibition, which can help determine the oncogenic potential of that gene of interest. An assay that provides a straightforward method to assess one aspect of the transforming potential of an oncogene is the Focus Formation Assay (FFA)2. When NIH 3T3 cells divide normally in culture, they do so until they reach a confluent monolayer. However, in the presence of an overexpressed oncogene, these cells can begin to grow in dense, multilayered foci1 that can be visualized and quantified by crystal violet or Hema 3 staining. In this article we describe the FFA protocol with retroviral transduction of the gene of interest into NIH 3T3 cells, and how to quantify the number of foci through staining. Retroviral transduction offers a more efficient method of gene delivery than transfection, and the use of an ecotropic murine retrovirus provides a biosafety control when working with potential human oncogenes.

MXD3 MYC / MAX / MAD ağının bir üyesi olan temel bir sarmal döngü-heliks lösin fermuar (bHLHZ) transkripsiyon faktörüdür. Bu MAD ailesinin 13-15 bir atipik üyesi olduğunu ve karsinogenezinde 16,17 rol bildirilmiştir. PBABEpuro (negatif kontrol) ve myc (pozitif kontrol) ile karşılaştırıldığında, MXD3 aşın NIH 3T3 yemekler önemli ölçüde daha az odakları (Şekil 1A) vardı. Şekil 1 B &#39;de veri önemini belirlemek için birden çok deney...

Watch this Scientific Journal Video about Focus Formation: A Cell-based Assay to Determine the Oncogenic Potential of a Gene at JoVE.com

Focus Formation: A Cell-based Assay to Determine the Oncogenic Potential of a Gene

Odak Oluşumu Testi aday onkogen dönüşürken potansiyelini değerlendirmek için basit bir yöntem sağlar.

Formation Odak: bir hücreye dayalı tahlil, bir genin onkojenik potansiyeli belirlemek için

Malignant transformation of cells is typically associated with increased proliferation, loss of contact inhibition, acquisition of anchorage-independent ...

focus-formation-cell-based-assay-to-determine-oncogenic-potential

Universidad de Cartagena UDEC

Research

JoVE Journal

Medicine

27.8K Görüntüleme.  University of California, Davis.  Odak Oluşumu Testi aday onkogen dönüşürken potansiyelini değerlendirmek için basit bir yöntem sağlar. 

Video: Focus Formation: A Cell-based Assay to Determine the Oncogenic Potential of a Gene

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.

İşlevsel Genomik Tarama kullanılması Kanser Hücre Sfero Kültürleri Potansiyel Yeni İlaç Hedefleri Belirlemek İçin

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

Kanser Araştırmaları

Colony Forming Cell (CFC) Assay for Human Hematopoietic Cells

Human hematopoietic stem/progenitor cells are usually obtained from bone marrow, cord blood, or peripheral blood and are used to study hematopoiesis and leukemogenesis. They have the capacity to differentiate into lymphoid and myeloid lineages. The colony forming cell (CFC) assay is used to study the proliferation and differentiation pattern of hematopoietic progenitors by their ability to form colonies in a semisolid medium. The number and the morphology of the colonies formed by a fixed number of input cells provide preliminary information about the ability of progenitors to differentiate and proliferate. Cells can be harvested from individual colonies or from the whole plate to further assess their numbers and differentiation states using flow cytometry and morphologic evaluation of Giemsa-stained slides. This assay is useful for assessing myeloid but not lymphoid differentiation. The term myeloid in this context is used in its wider sense to encompass granulocytic, monocytic, erythroid, and megakaryocytic lineages.

We have used this assay to assess the effects of oncogenes on the differentiation of primary human CD34+ cells derived from peripheral blood. For this purpose cells are transduced with either control retroviral construct or a construct expressing the oncogene of interest, in this case NUP98-HOXA9. We employ a commonly used retroviral vector, MSCV-IRES-GFP, that expresses a bicistronic mRNA that produces the gene of interest and a GFP marker. Cells are pre-activated by growing in the presence of cytokines for two days prior to retroviral transduction. After another two days, GFP+ cells are isolated by fluorescence-activated cell sorting (FACS) and mixed with a methylcellulose-containing semisolid medium supplemented with cytokines and incubated till colonies appear on the surface, typically 14 days. The number and morphology of the colonies are documented. Cells are then removed from the plates, washed, counted, and subjected to flow cytometry and morphologic examination. Flow cytometry with antibodies specific to the cell surface markers expressed during hematopoiesis provides information about lineage and maturation stage. Morphological studies of individual cells under a microscope after Wright- Giemsa staining provide further information with regard to lineage and maturation. Comparison of cells transduced with control empty vector to those transduced with an oncogene reveals the effects of the oncogene on hematopoietic differentiation.

Colony Forming Cell CFC Assay for Human Hematopoietic Cells

The colony forming cell (CFC) assay is an in vitro assay in which hematopoietic progenitors form colonies in a semi-solid medium. A combination of colony morphology, cell morphology, and flow cytometry are used to assess the ability of the progenitors to proliferate and differentiate along the different hematopoietic lineages.

Koloni Oluşturan İnsan Hematopoetik Hücreler Hücre (CFC) Testi

Human hematopoietic stem/progenitor cells are usually obtained from bone marrow, cord blood, or peripheral blood and are used to study hematopoiesis and ...

İmmünoloji ve Enfeksiyon

Genome-wide RNAi Screening to Identify Host Factors That Modulate Oncolytic Virus Therapy

High-throughput genome-wide RNAi (RNA interference) screening technology has been widely used for discovering host factors that impact&#160;virus replication. Here we present the application of this technology to uncovering host targets that specifically modulate the replication of Maraba virus, an oncolytic rhabdovirus, and vaccinia virus with the goal of enhancing therapy. While the protocol has been tested for use with oncolytic Maraba virus and oncolytic vaccinia virus, this approach is applicable to other oncolytic viruses and can also be utilized for identifying host targets that modulate virus replication in mammalian cells in general. This protocol describes the development and validation of an assay for high-throughput RNAi screening in mammalian cells, the key considerations and preparation steps important for conducting a primary high-throughput RNAi screen, and a step-by-step guide for conducting a primary high-throughput RNAi screen; in addition, it broadly outlines the methods for conducting secondary screen validation and tertiary validation studies. The benefit of high-throughput RNAi screening is that it allows one to catalogue, in an extensive and unbiased fashion, host factors that modulate any aspect of virus replication for which one can develop an in vitro assay such as infectivity, burst size, and cytotoxicity. It has the power to uncover biotherapeutic targets unforeseen based on current knowledge.

Here we describe a protocol for employing high-throughput RNAi screening to uncover host targets that can be manipulated to enhance oncolytic virus therapy, specifically rhabodvirus and vaccinia virus therapy, but it can be readily adapted to other oncolytic virus platforms or for discovering host genes that modulate virus replication generally.

Tedavi Oncolytic virusu modüle ana faktörleri tanımlamak için genom çapında RNAi tarama

High-throughput genome-wide RNAi (RNA interference) screening technology has been widely used for discovering host factors that impact&#160;virus ...

Methods for Evaluating the Role of c-Fos and Dusp1 in Oncogene Dependence

The demonstration of tyrosine kinase inhibitors (TKIs) in treating chronic myeloid leukemia (CML) has heralded a new era in cancer therapeutics. However, a small population of cells does not respond to TKI treatment, resulting in minimal residual disease (MRD); even the most potent TKIs fail to eradicate these cells. These MRD cells serve as a reservoir to develop resistance to therapy. Why TKI treatment is ineffective against MRD cells is not known. Growth factor signaling is implicated in supporting the survival of MRD cells during TKI treatment, but a mechanistic understanding is lacking. Recent studies demonstrated that an elevated c-Fos and Dusp1 expression as a result of convergent oncogenic and growth factor signaling in MRD cells mediate TKI resistance. The genetic and chemical inhibition of c-Fos and Dusp1 renders CML exquisitely sensitive to TKIs and cures CML in both genetic and humanized mouse models. We identified these target genes using multiple microarrays from TKI-sensitive and -resistant cells. Here, we provide methods for target validation using in vitro and in vivo mouse models. These methods can easily be applied to any target for genetic validation and therapeutic development.

Here, we describe protocols for the genetic and chemical validation of c-Fos and Dusp1 as a drug target in leukemia using in vitro and in vivo genetic and humanized mouse models. This method can be applied to any target for genetic validation and therapeutic development.

C-Fos rolü ve Dusp1 onkogen bağımlılığı değerlendirme yöntemleri

The demonstration of tyrosine kinase inhibitors (TKIs) in treating chronic myeloid leukemia (CML) has heralded a new era in cancer therapeutics. However, ...

Yeast As a Chassis for Developing Functional Assays to Study Human P53

The finding that the well-known mammalian P53 protein can act as a transcription factor (TF) in the yeast S. cerevisiae has allowed for the development of different functional assays to study the impacts of 1) binding site [i.e., response element (RE)] sequence variants on P53 transactivation specificity or 2) TP53 mutations, co-expressed cofactors, or small molecules on P53 transactivation activity. Different basic and translational research applications have been developed. Experimentally, these approaches exploit two major advantages of the yeast model. On one hand, the ease of genome editing enables quick construction of qualitative or quantitative reporter systems by exploiting isogenic strains that differ only at the level of a specific P53-RE to investigate sequence-specificity of P53-dependent transactivation. On the other hand, the availability of regulated systems for ectopic P53 expression allows the evaluation of transactivation in a wide range of protein expression. Reviewed in this report are extensively used systems that are based on color reporter genes, luciferase, and the growth of yeast to illustrate their main methodological steps and to critically assess their predictive power. Moreover, the extreme versatility of these approaches can be easily exploited to study different TFs including P63 and P73, which are other members of TP53 gene family.

Presented here are four protocols to construct and exploit yeast Saccharomyces cerevisiae reporter strains to study human P53 transactivation potential, impacts of its various cancer-associated mutations, co-expressed interacting proteins, and the effects of specific small molecules.

Insan p53 çalışma fonksiyonel Assays geliştirmek için bir şasi olarak Maya

The finding that the well-known mammalian P53 protein can act as a transcription factor (TF) in the yeast S. cerevisiae has allowed for the development of ...

Oncogenic Gene Fusion Detection Using Anchored Multiplex Polymerase Chain Reaction Followed by Next Generation Sequencing

Gene fusions frequently contribute to the oncogenic phenotype of many different types of cancer. Additionally, the presence of certain fusions in samples from cancer patients often directly influences diagnosis, prognosis, and/or therapy selection. As a result, the accurate detection of gene fusions has become a critical component of clinical management for many disease types. Until recently, clinical gene fusion detection was predominantly accomplished through the use of single-gene assays. However, the ever-growing list of gene fusions with clinical significance has created a need for assessing fusion status of multiple genes simultaneously. Next generation sequencing (NGS)-based testing has met this demand through the ability to sequence nucleic acid in massively parallel fashion. Multiple NGS-based approaches that employ different strategies for gene target enrichment are now available for use in clinical molecular diagnostics, each with its own strengths and weaknesses. This article describes the use of anchored multiplex PCR (AMP)-based target enrichment and library preparation followed by NGS to assess for gene fusions in clinical solid tumor specimens. AMP is unique among amplicon-based enrichment approaches in that it identifies gene fusions regardless of the identity of the fusion partner. Detailed here are both the wet-bench and data analysis steps that ensure accurate gene fusion detection from clinical samples.

This article details the use of an anchored multiplex polymerase chain reaction-based library preparation kit followed by next-generation sequencing to assess for oncogenic gene fusions in clinical solid tumor samples. Both wet-bench and data analysis steps are described.

Yeni nesil sıralamanın ardından bağlantılı Multiplex polimeraz zincir reaksiyonu kullanılarak Onkojenik gen füzyon tespiti

Gene fusions frequently contribute to the oncogenic phenotype of many different types of cancer. Additionally, the presence of certain fusions in samples ...

Mapping the Structure-Function Relationships of Disordered Oncogenic Transcription Factors Using Transcriptomic Analysis

Many cancers are characterized by chromosomal translocations which result in the expression of oncogenic fusion transcription factors. Typically, these proteins contain an intrinsically disordered domain (IDD) fused with the DNA-binding domain (DBD) of another protein and orchestrate widespread transcriptional changes to promote malignancy. These fusions are often the sole recurring genomic aberration in the cancers they cause, making them attractive therapeutic targets. However, targeting oncogenic transcription factors requires a better understanding of the mechanistic role that low-complexity, IDDs play in their function. The N-terminal domain of EWSR1 is an IDD involved in a variety of oncogenic fusion transcription factors, including EWS/FLI, EWS/ATF, and EWS/WT1. Here, we use RNA-sequencing to investigate the structural features of the EWS domain important for transcriptional function of EWS/FLI in Ewing sarcoma. First shRNA-mediated depletion of the endogenous fusion from Ewing sarcoma cells paired with ectopic expression of a variety of EWS-mutant constructs is performed. Then RNA-sequencing is used to analyze the transcriptomes of cells expressing these constructs to characterize the functional deficits associated with mutations in the EWS domain. By integrating the transcriptomic analyses with previously published information about EWS/FLI DNA binding motifs, and genomic localization, as well as functional assays for transforming ability, we were able to identify structural features of EWS/FLI important for oncogenesis and define a novel set of EWS/FLI target genes critical for Ewing sarcoma. This paper demonstrates the use of RNA-sequencing as a method to map the structure-function relationship of the intrinsically disordered domain of oncogenic transcription factors.

Intrinsically disordered domains are important for oncogenic fusion transcription factor function. To therapeutically target these proteins, a more detailed understanding of the regulatory mechanisms employed by these domains is required. Here, we use transcriptomics to map important structural features of the intrinsically disordered EWS domain in Ewing sarcoma.

Transcriptomik Analiz Kullanarak Düzensiz Onkojenik Transkripsiyon Faktörlerinin Yapı-fonksiyon İlişkilerinin Eşlenmesini

Many cancers are characterized by chromosomal translocations which result in the expression of oncogenic fusion transcription factors. Typically, these ...

A Multiplexed Luciferase-based Screening Platform for Interrogating Cancer-associated Signal Transduction in Cultured Cells

Genome-scale interrogation of gene function using RNA interference (RNAi) holds tremendous promise for the rapid identification of chemically tractable cancer cell vulnerabilities. Limiting the potential of this technology is the inability to rapidly delineate the mechanistic basis of phenotypic outcomes and thus inform the development of molecularly targeted therapeutic strategies. We outline here methods to deconstruct cellular phenotypes induced by RNAi-mediated gene targeting using multiplexed reporter systems that allow monitoring of key cancer cell-associated processes. This high-content screening methodology is versatile and can be readily adapted for the screening of other types of large molecular libraries.

Achieving a systems level understanding of cellular processes is a goal of modern-day cell biology. We describe here strategies for multiplexing luciferase reporters of various cellular function end-points to interrogate gene function using genome-scale RNAi libraries.

Kültür Hücreler Kanser ile ilişkili Sinyal İletimi sorgulanması için bir Multiplexed Lusiferaz tabanlı Tarama Platformu

Genome-scale interrogation of gene function using RNA interference (RNAi)  holds tremendous promise for the rapid identification of chemically tractable  ...

Tıp

Oncogene Expression Analysis with Alterations in pH in a Pancreatic Ductal Cell Line

The fourth leading cause of cancer-related death, pancreatic ductal adenocarcinoma (PDAC), has a 12% five-year survival rate. This disease has a poor prognosis and is characterized by a rigid stromal microenvironment, which represents a tangible challenge in its treatment. Chronic pancreatitis patients have a 10-fold greater risk of developing PDAC; in these patients, the ductal pH decreases from pH 8.0 to pH 6.0 due to bicarbonate insufficiency and the inflammatory milieu. Our goal was to understand the role of the acidic environment observed in chronic pancreatitis on oncogene expression in a pancreatic ductal cell line.
Therefore, 80% confluent human pancreatic ductal epithelial cells were incubated at pH 6.0 to pH 7.2 for 6 h. Total RNA from the cells was processed to enrich the total mRNA in the samples. Gene expression was evaluated via next-generation sequencing (NGS) of biological replicates. RNA-seq analysis was carried out with the aid of an online tool, and the differentially expressed genes (FCs &#60; &#177; 2.0) were identified; there were 90, 148, and 109 upregulated genes and 20, 14, and 23 downregulated genes at pH 6.0, 6.5, and 7.0, respectively. Four oncogenes were upregulated at pH 6.0, seven were upregulated at pH 6.5, and seven were upregulated at pH 7.0. The common genes that were upregulated at pH 6.0, pH 6.5, and pH 7.0 were lymphocyte cell-specific protein-tyrosine kinase (LCK) [pH 6.0, FC: 2.93; pH 6.5, FC: 2.93; pH 7.0, FC: 3.32], FGR proto-oncogene, Src family tyrosine kinase (FGR) [pH 6.0, FC: 4.17; pH 6.5, FC: 5.25; pH 7.0, FC: 5.09], and ArfGAP With SH3 domain, ankyrin repeat, and PH domain 3 (ASAP3) [pH 6.0, FC: 2.37; pH 6.5, FC: 3.84; pH 7.0, FC: 2.51]. The acidic environment triggers the activation of proto-oncogenes, which may trigger tumor initiation in chronic pancreatitis.

This study describes a protocol for exploring the effects of altered pH on oncogene expression via RNA-seq analysis of a pancreatic ductal cell line.

Pankreatik Duktal Hücre Hattında pH Değişiklikleri ile Onkogen Ekspresyon Analizi

The fourth leading cause of cancer-related death, pancreatic ductal adenocarcinoma (PDAC), has a 12% five-year survival rate. This disease has a poor ...

The Soft Agar Colony Formation Assay

Anchorage-independent growth is the ability of transformed cells to grow independently of a solid surface, and is a hallmark of carcinogenesis. The soft agar colony formation assay is a well-established method for characterizing this capability in vitro and is considered to be one of the most stringent tests for malignant transformation in cells. This assay also allows for semi-quantitative evaluation of this capability in response to various treatment conditions. Here, we will demonstrate the soft agar colony formation assay using a murine lung carcinoma cell line, CMT167, to demonstrate the tumor suppressive effects of two members of the Wnt signaling pathway, Wnt7A and Frizzled-9 (Fzd-9). Concurrent overexpression of Wnt7a and Fzd-9 caused an inhibition of colony formation in CMT167 cells. This shows that expression of Wnt7a ligand and its Frizzled-9 receptor is sufficient to suppress tumor growth in a murine lung carcinoma model.

The soft agar colony formation assay is a method used to confirm cellular anchorage-independent growth in vitro. The goal of this protocol is to illustrate a stringent method for the detection of the tumorigenic potential of transformed cells and the tumor suppressive effects of proteins on transformed cells.

Yumuşak Agar koloni formasyon deneyi

Anchorage-independent growth is the ability of transformed cells to grow independently of a solid surface, and is a hallmark of carcinogenesis. The soft ...