Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.701342
Title: Identifying common therapeutic targets in Merlin-deficient brain tumours
Author: Bassiri, Kayleigh
ISNI:       0000 0004 5991 2485
Awarding Body: University of Plymouth
Current Institution: University of Plymouth
Date of Award: 2016
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Abstract:
Neurofibromatosis type 2 (NF2) is an autosomal dominant inherited condition that predisposes individuals to develop multiple nervous system tumours, primarily schwannoma, meningioma and ependymoma. NF2 is characterised by loss of the tumour suppressor protein Merlin, caused by bi-allelic mutations of the encoding gene NF2 or by loss of heterozygosity. These tumours can occur either sporadically or as part of the NF2 condition. The majority are slow growing and display benign features, but this benignancy renders them largely unresponsive to classic chemotherapeutic agents leaving surgery and radiosurgery as the only remaining treatment options. Depending on their location, NF2-related tumours can cause a number of side effects, including nausea, balance problems, and in some cases hearing and/or vision loss. Phosphorylation is a key regulatory mechanism leading to changes in cell signalling. By identifying phosphoproteins that are significantly activated in tumour cells, novel therapies can be developed aiming to specifically target the phosphorylated status of these proteins thus ‘switching off’ the signalling cascade. The objective of this study is to identify and validate common targets in both Merlin-deficient meningioma and schwannoma to eventually exploit in novel therapeutic approaches. Using phosphoprotein purification followed by mass spectrometry analysis, we identified Signal Transducer and Activator of Transcription 1 (STAT1), phosphorylated at Serine (S) 727 and Tyrosine (Y) 701, PDZ and LIM domain protein 2 (PDLIM2), Heat Shock 70kDa Protein 1A (HSPA1A) and Filamin B (FLNB) as potential common, novel therapeutic targets. We validated these candidates in human primary meningioma and schwannoma tumour cells using a variety of techniques. We also showed that specific 7 knockdown of STAT1 and PDLIM2 was related to a significant decrease in cellular proliferation. Additionally, we performed co-immunoprecipitation using PDLIM2 as the bait protein and identified STAT1, HSPA1A and FLNB as binding partners, suggesting a novel interaction network involving all of the potential targets identified in this study. We also identified activation of several pathways and/ or biological processes in both tumour types that warrant further investigation i.e. endocytosis in schwannoma and the proteasome in meningioma. In conclusion, with our approach we substantially increased the overall body of knowledge regarding the proteome and phosphoproteome of meningioma and schwannoma. We generated a comprehensive set of data that highlighted several potential therapeutic targets and dysregulated pathways which will be further investigated.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.701342  DOI: Not available
Keywords: Meningioma ; Schwannoma ; Therapeutic targets ; Proteomics
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