Academic literature on the topic 'Trasposoni'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Trasposoni.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Trasposoni"

1

Cinar, Munevver, Steven Flygare, Marina Mosunjac, Ganji Nagaraju, Dongkyoo Park, Sheff Faith, Debra Saxe, and Leon Bernal-Mizrachi. "Trasposon Mediated Horizontal Gene Transfer (T-HGT) of Circulating Tumor DNA Reshapes MM Clonal Architecture." Blood 134, Supplement_1 (November 13, 2019): 3065. http://dx.doi.org/10.1182/blood-2019-126699.

Full text
Abstract:
Spatial genetic heterogeneity is a characteristic phenomenon that influences multiple myeloma's (MM) phenotype and drug sensitivity (Rasche L. et al and Bolli N et al.). Hence, the branch model of tumor evolution is not sufficient to explain the disorganized architecture observed in MM. In this study, we investigated whether MM ctDNA horizontal gene transfer (HGT) affect tumor genetic architecture and drug sensitivity, resembling what is seen in prokaryotes, and elucidated the mechanisms involved in the mobilization of genetic material from one cell to another. We identified that plasma from patients with MM transmits drug sensitivity or resistance to cells in culture. This transmission of drug sensitivity is mediated by ctDNA transfer of oncogenes to a host cell. Importantly, in vitro and in vivo demonstrated that ctDNA mainly targets cells resembling the cell of origin (tropism). Karyotype spreads and whole genome sequencing demonstrated that once patients ctDNA encounters host cells, it migrates into the nucleus where it ultimately integrates into the cell's genome. Integration to the genome was confirmed to be targeted to myeloma cells. Further sequencing analysis of multiple MM samples identified ctDNA tropism and integration is dependent on the 5' and 3' end presence of transposable elements (TE), particularly of the MIR and ALUsq family. These results were further validated by TE mediated delivery of GFP into MM cells in vitro and HSVTK in tumors of mouse xenografts. In conclusion, this data indicates for the first time that TE mediates MM ctDNA HGT into homologous tumor cells shaping the hierarchical architecture of tumor clones and affecting tumor response to treatment. Therapeutically, this unique quality of ctDNA can be exploited for targeted gene therapeutic approaches in MM and potentially other cancers. Disclosures Bernal-Mizrachi: Kodikas Therapeutic Solutions, Inc: Equity Ownership; TAKEDA: Research Funding; Winship Cancer Institute: Employment, Patents & Royalties.
APA, Harvard, Vancouver, ISO, and other styles
2

Nasution, Adnan Buyung. "IMPLEMENTASI PENGAMANAN DATA DENGAN MENGGUNAKAN ALGORITMA CAESAR CIPHER DAN TRANSPOSISI CIPHER." JURNAL TEKNOLOGI INFORMASI 3, no. 1 (July 20, 2019): 1. http://dx.doi.org/10.36294/jurti.v3i1.680.

Full text
Abstract:
Abstrack - The existence of data theft and misuse of data by unrelated groups causes the data to be no longer safe. Therefore, a security is needed that can make data safe from groups that are not concerned. Caesar Cipher Algorithm, which is the position of the original letter location changed through the alphabet. Transposition algorithm, which uses character permutations. Caesar Cipher and Transposition can secure data and restore data without changing the original form (plaintext).Keywords - Data Theft, Security, Caesar Chiper, Cipher Transposition Abstrack - Adanya pencurian data dan penyalahgunaan data oleh kelompok yang tidak bersangkutan menyebabkan data tidak terjaga lagi. Oleh karena itu, dibutuhkan suatu keamanan yang bisa membuat data aman dari kelompok yang tidak bersangkutan. Algoritma Caesar Cipher, yaitu posisi letak huruf asal diubah melalui alfabet. Algoritma Transposisi, yaitu menggunakan permutasi karakter. Caesar Cipher dan Transposisi dapat mengamankan data dan mengembalikan data tanpa merubah bentuk dari aslinya (plainteks).Kata Kunci - Pencurian Data, Keamanan, Caesar Chiper, Trasposisi Chiper
APA, Harvard, Vancouver, ISO, and other styles
3

Meli, Mariarita, and Eugenia Taranto. "Problemi con variazione ed equazione figurale: strumenti della didattica cinese trasposti in una scuola primaria italiana." Didattica della matematica. Dalla ricerca alle pratiche d’aula, no. 11 (May 18, 2022): 95–120. http://dx.doi.org/10.33683/ddm.22.11.5.

Full text
Abstract:
In questo lavoro viene mostrata la possibilità di sviluppare un approccio al pensiero pre-algebrico con alunni della scuola primaria che presti maggiore attenzione alle caratteristiche strutturali dei problemi additivi rispetto a quelle numeriche. In particolare, illustrando una sperimentazione condotta con allievi di una classe seconda primaria, si mira a mostrare come può concretizzarsi una trasposizione di strumenti didattici propri della didattica cinese – i problemi con variazione e l’equazione figurale – nel contesto italiano della scuola primaria. Si rileva come, a partire dal testo di un problema e dalla rappresentazione grafica dei suoi dati, i bambini sono in grado di comprendere e, a loro volta, costruire variazioni del problema di partenza, esplorando le potenzialità legate alla struttura della variazione stessa. I bambini sono così portati a sviluppare competenze d’uso di strutture di risoluzione di tipo pre-algebrico, spostando l’attenzione dal piano procedurale a quello relazionale.
APA, Harvard, Vancouver, ISO, and other styles
4

Morandi, Stefano, Paola Cremonesi, Tiziana Silvetti, and Milena Brasca. "Technological characterisation, antibiotic susceptibility and antimicrobial activity of wild-type Leuconostoc strains isolated from north Italian traditional cheeses." Journal of Dairy Research 80, no. 4 (September 26, 2013): 457–66. http://dx.doi.org/10.1017/s0022029913000447.

Full text
Abstract:
Genotypic and technological properties, antibiotic susceptibility and antimicrobial activity of 35 Leuconostoc strains, isolated from different Italian raw milk cheeses, were investigated. RAPD-PCR was used to study genetic variability and to distinguish closely related strains. The results showed a high degree of heterogeneity among isolates. All the strains had weak acidifying activity and showed low proteolytic and lipolytic activities. Reduction activity, was generally low. All the Leuconostoc were susceptible to ampicillin, mupirocin, erythromycin, quinupristin/dalfopristin and tetracycline. Many strains were classified as resistant to oxacillin, ciprofloxacin and nitrofurantonin, while all isolates were found resistant to vancomycin. PCR-based detection did not identify any of the common genetic determinants for vancomycin (vanA, vanB, vanC1, vanC2, vanC3, vanD, vanE, vanG) or erythromycin (ermB and ermC). Tetracycline resistance genes were detected in 25 tetracycline susceptible strains, the most frequent one being tetM. One strain, belonging to Ln. pseudomesenteroides species, was positive for the presence of the int gene of the Tn916/Tn1545 trasposon family. This is the first time the conjugative transposon Tn916 has been detected inside the Leuconostoc species. All strains showed antimicrobial activity against Enterococcus faecalis and Ent. faecium. The presence of genes encoding amino-acid decarboxylases (hdc and tdc) was not detected. Some strains are interesting in view of their use in cheese production as starter and non starter cultures.
APA, Harvard, Vancouver, ISO, and other styles
5

Tiswaya, Waway, and Abdul Hamid. "Transposisi Verba-Predikat Menjadi Nomina-Subjek dalam Kalimat Bahasa Indonesia dan Bahasa Sunda." MADAH 11, no. 1 (April 30, 2020): 1–14. http://dx.doi.org/10.31503/madah.v11i1.203.

Full text
Abstract:
Penelitian ini merupakan kajian bidang sintaksis yang memfokuskan pada transposisi verba predikat menjadi nomina subjek. Pengkajian transposisi konstituen verba predikat menjadi nomina subjek dalam kalimat bahasa Indonesia dan bahasa Sunda dibatasai pada perubahan konstruksi, struktur, dan tataran gramatikal. Tujuan penelitian ini adalah mendeskripsikan konstruksi konstituen subjek, perubahan fungsi lain, perubahan kategori, perubahan tataran gramatikal, dan unsur yang berperan. Trasposisi verba predikat menjadi nomina subjek merupakan kajian yang penting dan menarik karena dalam bahasa Indonesia dan bahasa Sunda gejala kebahasaan ini banyak ditemukan, tetapi belum dikaidahkan. Metode yang digunakan dalam penelitian ini adalah metode kualitatif dengan penyajian data deskriptif yang menggunakan metode dan teknik distribusional pada tahap analisis data. Hasil pengkajian menunjukkan hal-hal sebagai berikut. (a) Dalam transposisi konstituen verba predikat menjadi nomina subjek terjadi pengedepanan konstituen verba predikat. (b) Transposisi konstituen verba predikat menjadi nomina subjek melibatkan morfem, baik morfem afiks maupun morfem kata. (c) Transposisi konstituen verba predikat menjadi nomina subjek menunjukkan terjadinya penominaan (nominalisasi) konstituen. (d) Transposisi konstituen verba predikat menjadi nomina subjek menghilangkan fungsi sintaksis pendamping verba predikat asal dan cenderung terjadi perubahan struktur pada nomina subjek. (e) Transposisi konstituen verba predikat menjadi nomina subjek cenderung mengubah tata tingkat (tataran) gramatikal, yakni kata polimorfemis menjadi monomorfemis atau sebaliknya, frase menjadi kata, dan klausa atau kalimat menjadi frase. Seluruh proses transposisi verba predikat menjadi nomina subjek tersebut dipicu oleh adanya pengutamaan topik-komen yang dinyatakan oleh penutur ujaran tersebut.
APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic "Trasposoni"

1

VADALÀ, REBECCA. "Epigenetic role of transposable elements in human T lymphocytes identity and plasticity." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2022. http://hdl.handle.net/10281/382318.

Full text
Abstract:
I linfociti infiltranti il tumore (TIL) sono i componenti principali del microambiente tumorale e svolgono un ruolo centrale nell'immunità antitumorale. Durante l'immunoediting del cancro, i TIL diventano disfunzionali, un fenotipo associato alla compromissione delle funzioni effettrici, alla ridotta crescita cellulare e alla ridotta capacità di uccisione. Infatti, i trattamenti di immunoterapie contro il cancro cercano di ripristinare lo stato disfunzionale dei TIL al fine di promuovere la clearance del tumore. Le immunoterapie rappresentano oggigiorno la nuova frontiera nella lotta contro il cancro, ma ancora poco si sa per quanto riguarda i modulatori epigenetici responsabili delle proprietà dei TIL; la scoperta di nuove molecole e meccanismi di azione possibili potrebbe migliorare sostanzialmente le conoscenze relative alle immunoterapie e alla reattività del paziente ad esse. Per questo motivo, stiamo applicando nuovi approcci e tecnologie in questo campo, vale a dire lo studio delle funzioni degli elementi trasponibili (TE) come nuovi attori epigenetici nell'identità, nella plasticità e nell'adattabilità dei TIL all'ambiente tumorale. I TE sono sequenze di DNA ripetute che coprono il 40-45% del genoma umano e diversi studi suggeriscono che i TE esercitano una funzione cruciale nella regolazione epigenetica sia in cis che in trans, essendo una fonte di RNA regolatori non codificanti e partecipando al ripiegamento della cromatina. Tra i TE, siamo interessati alle possibili funzioni epigenetiche degli elementi LINE1, che rappresentano il 18% del genoma umano, considerati come nuove molecole chiave coinvolte nella regolazione epigenetica dell'identità cellulare. Fino ad oggi il ruolo e la dinamica degli RNA derivati dai TEs sono stati studiati solo nelle cellule staminali embrionali o durante lo sviluppo dell'organismo, mentre non c'era evidenza delle loro possibili funzioni in cellule completamente differenziate derivate da tessuti adulti, come i linfociti T umani, che sono cellule plastiche in grado di adattarsi e differenziarsi in base all'ambiente circostante. Abbiamo dimostrato che, tra i sottotipi di cellule T, esiste un arricchimento specifico per gli RNA associati alla cromatina LINE1 nelle cellule T CD4 + naïve. Inoltre, gli RNA LINE1 mostrano una dinamica specifica e tempestiva, essendo rapidamente downregolati dopo l'attivazione del TCR. In particolare, esperimenti funzionali hanno suggerito che questi RNA potrebbero regolare le funzioni effettrici dei linfociti T. A seguito di queste evidenze, lo scopo di questa tesi è stato quello di valutare il coinvolgimento di LINE1 nella regolazione epigenetica dell'identità cellulare e delle funzioni nei TIL. Abbiamo generato un modello in vitro per studiare la dinamica di LINE1 in cellule T esauste e disfunzionali, inoltre, abbiamo avuto la possibilità di isolare da pazienti con tumore al colon e al polmone i TIL dai tessuti tumorali e dalla loro controparte normale per eseguire esperimenti funzionali e valutare le funzioni di LINE1 in un contesto patologico. Abbiamo dimostrato che le TIL mostrano un riaccumulo aberrante degli RNA di LINE1 che è associato al fenotipo disfunzionale e che il silenziamento di questi RNA è sufficiente per riattivare le loro funzioni effettrici e di uccisione permettendo una reversione del fenotipo. Infine, miriamo a definire gli RNA di LINE1 come nuove molecole regolatrici di TIL per trovare nuove molecole di RNA che potrebbero essere utilizzate come adiuvanti nella terapia per rafforzare la risposta immunitaria del paziente.
Tumor infiltrating lymphocytes (TILs) are the principal components of the tumor microenvironment, and play a central role in antitumor immunity. During cancer immunoediting, TILs became dysfunctional, a phenotype associated to effector functions impairment, reduced cell growth and decreased killing capability. Indeed, cancer immunotherapies treatments try to revert TILs dysfunctional state in order to promote tumor clearance. Immunotherapies nowadays represent the novel frontier in fighting cancer but still little is known regarding the epigenetic modulators responsible for TILs properties; the discovery of novel, possible targetable molecules and mechanisms could substantially improve knowledges regarding immunotherapies and patient responsiveness to them. For this reason, we are applying novel approaches and technologies in this filed, namely the investigation of transposable elements (TEs) functions as novel epigenetic players in TILs identity, plasticity and adaptability to the environmental cancer driven milieu. TEs are interspersed repetitive DNA sequences that cover 40 - 45% of the human genome and growing evidence suggests that TEs exert a crucial function in epigenetic regulation both in cis and in trans, being a source of non-coding regulatory RNAs and participating to chromatin folding. Among TEs, we are interested in the possible epigenetic functions of LINE1 elements, that represents 18% of the human genome, considered as novel key molecules involved in epigenetic regulation of cell identity. Until today the role and the dynamics of TEs-derived RNAs were investigated only in embryonic stem cells or during organism development, while there was no evidence of their possible functions in fully differentiated cells derived from adult tissues, as human Naïve T lymphocytes, that are plastic cells able to adapt and differentiate to diverse effector cells based on the cytokine milieu. We demonstrate that, among T cells subsets, there is a specific enrichment for LINE1 chromatin associated RNAs in naïve CD4+ T cells. Moreover, LINE1 RNAs show a peculiar and timely specific dynamic, being rapidly depleted from the nuclei after TCR activation. Notably, functional experiments suggested that these transcripts could regulate T cells effector functions. Since these data, the aim of this thesis is to evaluate LINE1 involvement in the epigenetic regulation of cell identity and functions in TILs. We generated an in vitro model to study LINE1 dynamics in exhausted and dysfunctional T cells, moreover, we had the possibility to isolate ex vivo TILs from NSCL cancer, CRC and their normal counterpart derived from patients to perform functional experiments and assess LINE1 functions in a real pathological context. We have demonstrated that TILs show aberrant re-accumulation of LINE1 RNAs which is associated with the dysfunctional phenotype and that the silencing of these RNAs is sufficient to reactivate their effector and killing functions allowing a reversion of the phenotype. Finally, we aim to define LINE1 RNAs as novel TILs regulatory molecules to find novel targetable RNA molecules that could be used as adjuvants in therapy to reinforce patient’s immune response.
APA, Harvard, Vancouver, ISO, and other styles
2

BARBON, Elena. "Development of cellular and animal models of coagulation factors deficiencies for the assessment of innovative therapeutic approaches acting on transcriptional and post-transcriptional regulation." Doctoral thesis, Università degli studi di Ferrara, 2015. http://hdl.handle.net/11392/2388976.

Full text
Abstract:
In the last decades, enormous efforts have been pushed toward the development of molecular therapeutic approaches for human genetic diseases, and the research all over the world has obtained remarkable achievements, especially in gene therapy field. Notwithstanding, the intense research also led to potential therapeutic strategies based on the correction of the specific disease-causing defects, which might circumvent some limitations of gene replacement therapy. These approaches are of great interest for patients with coagulation deficiencies, since they would benefit even from small increase in functional protein levels. This work propose the development of in-vitro and in–vivo models of rare bleeding disorders, in order to explore corrective molecular approaches acting on the specific disease-causing defects, both at transcriptional and post-transcriptional level. The first part of this work deals with the usage of engineered transcription factors (eTFs) as potential therapeutic strategy for factor VII (F7) deficiency caused by two severe promoter mutations. Through the expression of gene reporter plasmids we created a cellular model for the two F7 promoter variants. Then, we assembled four eTFs (TF1-4) designed to target different regions on the F7 proximal promoter in order to test their efficacy in stimulating transcriptional activity on the target gene. The treatment with the different eTFs demonstrated that TF4, targeting a sequence between the mutations, induced a robust increase of gene transcription in the presence of the defective promoter. Interestingly, TF4 appreciably increased the endogenous F7 transcription and mRNA levels in HepG2 cells and induced F7 expression in Hek293 cells that do not virtually express factor VII. The second part describes the exploitation of the Sleeping Beauty Transposon System (SBTS) to develop cellular and mouse model of haemophilia B (HB) caused by splicing mutations, in order to assess the efficacy of an RNA-based therapeutic approach. In the last years, modified small nuclear RNAs U1 (U1snRNAs) have been exploited to correct splicing mutations causing severe coagulation factor VII deficiency and HB, but only in minigenes assays. Therefore, the evaluation of the U1snRNA-mediated correction strategy in–vivo implies the creation of proper mouse models for each specific splicing-variant, not yet available. Here we used the SBTS to develop cellular/mouse models of HB caused by the factor IX ex5-2C splicing variant. We have generated Hek293 stable clones expressing the normal or mutated human splicing-competent factor IX cassettes integrated into the genome as a result of the transposase activity. These preliminary studies provided us with optimized experimental protocol to create cellular models of human disease caused by splicing mutations. This also provides with the rationale for the creation of mouse models through hydrodynamic injection of the transposon plasmids and of the transposase in wt mice, for the assessment of the modified U1 snRNAs-mediated rescue in–vivo in a genomic expression context instead of a transient episomal system.
APA, Harvard, Vancouver, ISO, and other styles
3

Grisard, Eleonora. "BTBD7, a gene identified with a transposon based forward genetic screening, is important for colorectal cancer metastasis." Doctoral thesis, Università degli studi di Padova, 2017. http://hdl.handle.net/11577/3425851.

Full text
Abstract:
Colorectal cancer (CRC) is the second most lethal cancer because of the metastatic spread of the primary tumor. A current hypothesis is that metastasis relies on epithelial to mesenchymal transition (EMT), which is a biological process in which epithelial cells gradually loose epithelial features to switch to a mesenchymal program. In vitro assays that select EMT cells are fundamental to perform in vitro genetic screens that select cells switched to EMT program. For instance, in vitro anoikis assay consists in growing cells in low adherence conditions (loss of cell-matrix contacts) and has been used to select more aggressive tumor cells; however, some tumor cells survive to loss of cell-matrix contacts by strengthening cell-cell contacts, which is counteracting for cells that undergo to EMT. An assay that was developed in our lab and was named Forced Single Cell Suspension Assay (fSCS) is more stringent compared to in vitro anoikis and selects for cells that undergo EMT. The non-coding part of the genome, despite having a fundamental role in regulating EMT and metastasis (e.g miRNAs) is less studied respect to the protein-coding counterpart. Transposon based screens interrogate the genome more randomly than other screens (e.g retroviral based screens). To perform an in vitro assay that permits the high-throughput screening of EMT genes, we combined fSCS with an in vitro Sleeping Beauty (SB) transposon (TN) based screen in HCT116 CRC cells. We identified a cell clone, TN4_20, that shows the following features: greatest fSCS resistance, mesenchymal morphology, expression of EMT markers (e.g. Slug ↑, Twist ↑, Vimentin ↑, E-cadherin ↓, Has-2 ↑), and the ability to generate more satellite colonies in matrigel evasion assay. Moreover, in a pilot in vivo experiment, TN4_20 intra-caecal injected mice developed distant metastases compared to control. We retrieved the genomic position of TN insertions from TN4_20 genomic DNA, and we focused on the TN insertion located within the 3’ UTR of BTBD7. We chose to study this insertion because BTBD7 is a known EMT and metastasis regulator and because, interestingly, this TN insertion locates within the predicted target site of miR-23b, a known anti-metastatic miRNA. We hypothesized and demonstrated that miR-23b targets BTBD7 gene, and our data suggest that TN insertion impairs miR-23b/BTBD7 interaction. Moreover, we demonstrated that the interaction between miR-23b and BTBD7 is important for fSCS resistance. We found that Btbd7 silencing impairs fSCS survival in HCT116 parental and in TN4_20, and that the overexpression of ectopic eGFP-Btbd7 in HCT116 parental confers fSCS resistance and the ability to generate more satellite colonies in matrigel evasion assay. Moreover, the overexpression of ectopic eGFP-Btbd7 induces the down-regulation of E-cadherin at the mRNA and protein level, and the up-regulation of Vimentin, both markers of EMT. In addition, Btbd7 overexpression up-regulates Zeb-1 transcription factor mRNA and protein levels. In an extended version of our TN- fSCS based screen, by performing sequential rounds of fSCS in both HCT116 Parental and Piggybac (PB) TN-cells, we obtained pools of fSCS resistant cells, instead of single clones. We observed that cells that survived to each round of fSCS generated more surviving colonies and acquired a greater scattered/mesenchymal morphology. Moreover, surviving colonies after fSCS showed decreased E-cadherin expression, increased Vimentin expression and increased number of cells with EpCAM low (dim), suggesting that multiple rounds of fSCS enriches for EMT/stem-cell traits. In addition, we observed that enriched fSCS resistant cells showed increased resistance to 5-fluoro-uracil (5FU) treatment and increased in vivo metastatic potential. Finally, repeated rounds of fSCS enrich for two families of miRNAs, miR-30 and miR-302 that were already shown to regulate EMT and metastasis and that may potentially regulate fSCS resistance.
Il tumore del colon-retto è il secondo tumore più letale a causa della diffusione metastatica della lesione primaria. Un’ipotesi attuale è che la metastasi sia basata sulla transizione epitelio-mesenchimale (in inglese EMT, epithelial to mesenchymal transition), un processo biologico in cui le cellule epiteliali perdono gradualmente i loro caratteri epiteliali per convertirsi a un programma di tipo mesenchimale. I saggi in vitro che selezionano cellule EMT sono fondamentali per poter fare screening genetici che selezionano cellule che si sono convertite al programma EMT. Ad esempio, il saggio in vitro di anoikis si basa sulla crescita delle cellule in condizioni di mancanza di attacco alla matrice ed è stato usato per selezionare cellule con fenotipo più aggressivo; tuttavia alcuni tipi di cellule tumorali sono capaci di resistere a queste condizioni di crescita rafforzando i contatti cellula-cellula, un comportamento in netto contrasto con il fenotipo EMT. Un saggio in vitro sviluppato nel nostro laboratorio, denominato forced Single Cell Suspension assay (fSCS) si è rivelato più stringente rispetto al saggio in vitro di anoikis e seleziona cellule andate incontro alla EMT. La parte non codificante del genoma, nonostante abbia un ruolo fondamentale nella regolazione della EMT e nella metastasi (come avviene ad esempio per i miRNA), risulta molto meno studiata rispetto alla controparte codificante. I saggi genetici in vitro basati sull’uso di trasposoni interrogano il genoma in modo più randomico rispetto ad altri tipi di saggi (ad esempio quelli basati sull’uso di retrovirus). Per avvalerci di un saggio in vitro che consenta uno screening molto efficiente dei geni che regolano la EMT, abbiamo combinato il saggio di fSCS con uno screening genetico in vitro basato sull’uso del trasposone Sleeping Beauty in cellule di cancro colo-rettale HCT116. Abbiamo identificato un clone cellulare, TN4_20, che mostra le seguenti caratteristiche: maggior resistenza al saggio di fSCS, morfologia mesenchimale, espressione di marcatori della EMT (ad esempio Slug ↑, Twist ↑, Vimentin ↑, E-cadherin ↓, Has-2 ↑), e abilità di generare un maggior numero di colonie satelliti nel saggio di evasione in matrigel. Inoltre, in un esperimento pilota condotto in vivo, le cellule TN4_20, iniettate in topi mediante iniezione intra-cecale, formano metastasi a distanza. Dopo essere risaliti alle posizioni genomiche delle inserzioni del trasposone nel DNA genomico delle TN4_20, ci siamo focalizzati sull’inserzione localizzata nella 3’UTR (3’ regione non tradotta) del gene BTBD7. Abbiamo scelto di studiare questa inserzione perché BTBD7 è un noto regolatore di EMT e metastasi e perché questa inserzione del trasposone è localizzata nel sito bersaglio predetto del miR-23b, un miRNA con note funzioni anti-metastatiche. Abbiamo ipotizzato e dimostrato che il miR-23b bersaglia il gene BTBD7 e i nostri dati suggeriscono che l’inserzione del trasposone nella 3’UTR di BTBD7 interferisce con questa interazione. Inoltre, abbiamo dimostrato che l’interazione tra il miR-23b e BTBD7 è importante per la resistenza all’ fSCS. I nostri risultati inoltre dimostrano che il silenziamento di BTBD7 interferisce con la resistenza all’ fSCS sia in cellule HCT116 parentali che TN4_20, e che la over-espressione di un costrutto ectopico eGFP-Btbd7 in cellule HCT116 parentali conferisce resistenza all’ fSCS e l’abilità di generare un maggior numero di colonie satelliti nel saggio di evasione in matrigel. Inoltre, l’over-espressione di eGFP-Btbd7 induce una riduzione dei livelli di trascritto e di proteina di E-caderina, e un aumento dei livelli di Vimentina, entrambi marcatori di EMT. In più, la over-espressione di eGFP-Btbd7 aumenta i livelli di trascritto e di proteina del fattore di trascrizione Zeb-1. In una versione estesa del nostro saggio, attraverso l’esecuzione di round multipli di fSCS sia in cellule HCT116 parentali che in cellule HCT116 trasposte con il trasposone Piggybac (PB), abbiamo ottenuto gruppi, e non singoli cloni, di cellule resistenti all’ fSCS. Abbiamo osservato che cellule che sopravvivono a ogni round di fSCS generano un maggior numero di colonie sopravviventi, le quali acquisiscono una morfologia più mesenchimale. Inoltre, le colonie di cellule sopravvissute all’ fSCS mostrano ridotti livelli di espressione di E-caderina, aumentati livelli di espressione di Vimentina, e un aumentato numero di cellule con ridotta espressione di EpCAM, suggerendo che round multipli di fSCS determinano un arricchimento di cellule con tratti di EMT e staminalità. Inoltre, abbiamo osservato che cellule resistenti all’fSCS mostrano una maggiore resistenza al trattamento con 5-fluororacile (5-FU) e un aumentato potenziale metastatico in vivo. Infine, round ripetuti di fSCS arricchiscono due famiglie di miRNA, cioè miR-30 e miR-302, che sono già stati descritte avere un ruolo nella EMT e nella metastasi, e che potrebbero quindi regolare anche la resistenza all’ fSCS.
APA, Harvard, Vancouver, ISO, and other styles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography