Di Cecilia, Serena (2015) A Novel Long Non-Coding RNA Transcript Regulates The Fate of Colon Cancer Initiation. [Tesi di dottorato]

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Item Type: Tesi di dottorato
Lingua: English
Title: A Novel Long Non-Coding RNA Transcript Regulates The Fate of Colon Cancer Initiation
Creators:
CreatorsEmail
Di Cecilia, Serenaserenadicecilia@gmail.com
Date: 2 March 2015
Number of Pages: 108
Institution: Università degli Studi di Napoli Federico II
Department: Scienze Mediche Traslazionali
Scuola di dottorato: SEMM - European School of Molecular Medicine
Dottorato: PhD in Molecular Medicine (Molecular Oncology or Human Genetics)
Ciclo di dottorato: 26
Coordinatore del Corso di dottorato:
nomeemail
Ballabio, Andreaballabio@igem.it
Tutor:
nomeemail
Salvatore, FrancescoUNSPECIFIED
Del Vecchio, LuigiUNSPECIFIED
Martin, WalshUNSPECIFIED
Date: 2 March 2015
Number of Pages: 108
Uncontrolled Keywords: lncRNA, Colon Cancer initiating cells, Wnt-signalling, LUST
Settori scientifico-disciplinari del MIUR: Area 05 - Scienze biologiche > BIO/12 - Biochimica clinica e biologia molecolare clinica
Area 06 - Scienze mediche > MED/03 - Genetica medica
Date Deposited: 12 Jun 2015 10:11
Last Modified: 31 Dec 2016 02:00
URI: http://www.fedoa.unina.it/id/eprint/10058
DOI: 10.6092/UNINA/FEDOA/10058

Abstract

Cancer Initiating cells are a small population of cancer cells capable of tumor initiation and growth. Characteristic of these cells are the expression of “stem-like” markers and the common alteration of the Wnt/β-catenin and Notch pathways. In my thesis, I characterized Colon Cancer Initiating Cells (CCICs) by FACS analysis from HT-29 colon cancer cell line. I then performed in vitro colonospheres-forming assay and RNA-Seq, to interrogate the genome-wide signature involving CCICs. My results show that members of Wnt/β-catenin pathway are elevated in CCICs and colonospheres, when compared to a more differentiated population. Moreover, genes directing the differentiation were silenced in CCICs and colonospheres. These results demonstrate the self-renewal and proliferation capacity of the isolated CCICs population, and that this subpopulation resembles a strong Wnt-signaling pathway signature. Additionally, several lncRNAs are dys-regulated in CCICs, and my findings identify LUST/RBM5-AS1 as a lncRNA transcript strongly elevated during colonospheres formation. The expression of LUST and stem-like markers CD24 and CD44, and expression of Wnt-signaling corresponds with cells that can survive and grow in serum-free media. Loss of LUST impairs Wnt-signaling at mRNA and protein levels, while LUST overexpression provides enhanced and synergistic signaling mediated through Wnt and β-catenin at the mRNA and protein levels. Nuclear/Cytoplasmic RNA fractionation and RNA-FISH show that LUST essentially is a nuclear transcript. RNA immuno-precipitation and UV cross-linking immuno-precipitation assays show that LUST RNA binds to β-catenin. Finally, LUST overexpression enhances colonospheres formation more rapidly. Collectively, my findings reveal that the lncRNA LUST regulates Wnt pathway in CCICs through a coordinated physical interaction with β-catenin, acting through transcriptional regulation to promote colon cancer initiating cells maintenance.

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