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dc.contributor.advisorShnyder, Steven D.
dc.contributor.advisorFalconer, Robert A.
dc.contributor.authorSaeed, Rida F.*
dc.date.accessioned2017-12-07T15:09:12Z
dc.date.available2017-12-07T15:09:12Z
dc.date.issued2015
dc.identifier.urihttp://hdl.handle.net/10454/14108
dc.description.abstractPolysialic acid is aunique carbohydrate that decorates the surface of the neural cell adhesion molecule. Polysialic acidis an onco-developmental antigen, expressed in tumours principally of neuroendocrine origin, notably neuroblastoma,strongly correlating with invasion and metastasis. Polysialylation is regulated by two polysialyltransferase enzymes, PST(ST8SiaIV)and STX(ST8SiaII),withSTX dominant in cancer. Post-development polysialic acid expression is only found at low levels in the brain, thus this could be a novel target for cancer therapy. It is hypothesized that inhibition of polysialyltransferasecould lead to control of tumour dissemination and metastasis.The aims of this thesis were to develop tools and in vitro assays to screen novel polysialyltransferaseinhibitors. A panel of tumour cell lines were characterised in terms of growth parameters (using the MTT assay) and polysialic acid expression. This includes a pair of isogenic C6 rat glioma cells (C6-STX and C6-WT) and naturally polysialic acid expressing neuroblastoma cells(SH-SY5Y). Following this, an in vitro assay was validated to screen modulation of polysialic acid expression by removing pre-existing polysialic acid expression using endoneuraminidase N and evaluated the amount of re-expression of polysialic acid using immunocytochemistry. Then, a functional assay was developed and validated for invasion, the matrigel invasion assay. Cytidine monophosphate (tool compound) significantly reduced polysialic acidsurface expression and invasion. A panel of six novel polysialyltransferase inhibitors was screened for cytotoxicity, polysialic acidsurface expression and invasion. Of the potential polysialyltransferase inhibitorsevaluated, ICT3176 and ICT3172 were identified from virtual screening of Maybridge library and were emerged as the most promising inhibitors, demonstrating significant (p<0.05)reduction in cell-surface polysialic acidre-expression and invasion in polysialic acid expressing cells.Furthermore, the specificity of compounds for polysialyltransferase (α-2,8-sialyltransferase) over othermembers of the wider sialyltransferase family (α-2,3-and α-2,6-sialyltransferases) was confirmed using differential lectin staining. These results demonstrated that small molecule inhibitors as STX is possible and provides suitable in vitrocell based assays to discovery more potent derivatives.en
dc.language.isoenen_US
dc.rights<a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nc-nd/3.0/88x31.png" /></a><br />The University of Bradford theses are licenced under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/">Creative Commons Licence</a>.en_US
dc.subjectPolysialic acid; Neural cell adhesion molecule; Neuroblastoma; Polysialyltransferase; Metastasis; Invasion; Cancer therapeutics; Transwell invasion assay; Sialic acid expressionen_US
dc.titleInvestigation of inhibitors of polysialyltransferase as novel therapeutics for neuroblastoma. Development of in vitro assays to assess the functionality and selectivity of novel small-molecule inhibitors of polysialyltransferases for use in neuroblastoma therapyen_US
dc.type.qualificationleveldoctoralen_US
dc.publisher.institutionUniversity of Bradfordeng
dc.publisher.departmentInstitute of Cancer Therapeutics, Faculty of Life Sciencesen_US
dc.typeThesiseng
dc.type.qualificationnamePhDen_US
dc.date.awarded2015
refterms.dateFOA2019-06-05T11:20:30Z


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