Date of Award

Summer 2017

Document type

Thesis

Degree Name

PhD (Doctor of Philosophy)

First Supervisor

Dr Olga Piskareva

Second Supervisor

Professor Ray Stallings

Funder/Sponsor

National Childrens Research Centre (NCRC)

Keywords

Neuroblastoma, Drug Therapy, Drug Resistance

Abstract

Neuroblastoma is a highly heterogeneous disease, responsible for 15 % of paediatric cancer deaths. Acquired drug resistance is a major obstacle in high risk neuroblastoma, making the elucidation of mechanisms in development and modulation of drug resistance essential.

Three drug-resistant models, KellyCis83, CHP212Cis100 and SK-N-ASCis24 were developed previously to elucidate mechanisms involved in cisplatin resistance development.

Cisplatin resistance induces phenotypic changes in neuroblastoma. The aim of this work was to characterise phenotypic and proteomic changes and validate a miRNA capable of regulating the expression of up-regulated genes from proteomic analysis of cisplatin resistant sub-lines.

Proteomic profiling was carried out on the MYCN amplified KellyCis83 and non-MYCN amplified SK-N-ASCis24, which demonstrated cross resistance. Profiling identified an increase in proteins involved with ILK signalling, actin cytoskeletal signalling, epithelial adherens junction signalling and remodelling of epithelial adherens junctions pathways, indicating a mesenchymal phenotype in SK-N-ASCis24.

MiR-124-3p targets overexpressed proteins from our dataset and low expression is associated with poor survival in a cohort of non-MYCN amplified tumours. Microfluidic card and individual Taqman analysis of miR-124-3p did not find decreased expression in SK-N-ASCis24.

We conclude; rather than acting as a powerful inducer of apoptosis or cell cycle arrest, miR-124-3p decreased cell viability through a more subtle mechanism, targeting a large proportion of cytoskeletal genes associated with cell cycle checkpoints and proliferation. Gene ontology analysis of miR-124-3p targets provided a better understanding of the extensive cellular processes and mechanisms targeted by this tumour suppressor miRNA, demonstrating the highly context and cancer type dependent role of miR-124-3p.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 4.0 License.

File Size

28.2 MB

Comments

A thesis submitted for the degree of Doctor of Philosophy from the Royal College of Surgeons in Ireland in 2017.

Available for download on Sunday, June 30, 2019

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