Thesis
Disrupting inhibitory-kappaB kinase (IKK)-Aurora kinase signalling in prostate cancer cells
- Creator
- Rights statement
- Awarding institution
- University of Strathclyde
- Date of award
- 2021
- Thesis identifier
- T16039
- Person Identifier (Local)
- 201658328
- Qualification Level
- Qualification Name
- Department, School or Faculty
- Abstract
- Prostate cancer (PCa) is the second most common cause of cancer-related death in men. Aurora kinase A (AURKA) is commonly overexpressed in PCa and when active is bound to its activating cofactor, Targeting protein for Xklp2 (TPX2), preventing the dephosphorylation and degradation of AURKA. AURKA interacts with the IκB kinase (IKK) proteins, IKKα, IKKβ, and IKKγ or NF-kappa-B essential modulator (NEMO). From mapped binding studies an IKKβderived NEMO-binding domain (NBD) peptide was developed as a competitive disruptor of IKK-AURKA signalling and was hypothesised to allosterically modulate AURKA-TPX2 status. The NBD peptide in a cell-permeable (CPP) Wild-type form (WT; 100µM), also known to inhibit canonical NF-κB activation, was identified to significantly (p<0.05) accelerate AURKA dephosphorylation/degradation through mitosis and had a similar effect on TPX2, Polo-like kinase-1 (PLK1) status in PC3 prostate cancer cells. Pharmacological and molecular techniques alongside genetically modified cell models (wild type and ikka-/-/ikkb-/--double ‘knockout’ (KO) murine embryonic fibroblasts (MEFs)) were used to target/characterise different aspects of IKK signalling and so elucidate the mechanism of disrupting IKK-AURKA signalling. Small molecule inhibitors and siRNA targeting IKKα/β had minimal effect upon AURKA and TPX2 status. The NBD WT CPP caused mechanistic disruption of AURKA-TPX2-PLK1 status and phenotypic characteristics in different solid tumours; LNCaP AIs (AR+ve prostate cancer); MCF7 (ER+ve breast cancer), T98G (glioblastoma). NBD WT CPP plus ATP-competitive AURK inhibitors significantly (p<0.05) accelerated AURK dephosphorylation/degradation and TPX2 degradation in PCa cells which correlated with a synergistic (CI < 1) inhibition of phenotypic outcomes - rank order of potency: VX-680 > ZM447439 > Aurora kinase/CDK inhibitor > Aurora kinase inhibitor II > Aurora kinase inhibitor III. Hence, the NBD peptide may support two-site targeting of AURKA-TPX2 signalling, potentially improve access to the AURKA catalytic site and therefore be an advance towards pre-clinical molecules/mimetics that can potentially enhance the efficacy and clinical outcome of AURK inhibitors.
- Advisor / supervisor
- Plevin, Robin.
- Paul, Andrew.
- Resource Type
- DOI
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PDF of thesis T16039 | 2021-10-25 | Public | Download |