Investigating aryl-sulphonamides as dual inhibitors of splicing and metabolism for the potential treatment of neuroblastoma
File(s)
Author(s)
Herendi, Lili
Type
Thesis
Abstract
Neuroblastoma is one of the most common paediatric solid tumours with a poor prognosis for high-risk patients, highlighting the need for novel therapies. In this study, I analysed public drug sensitivity data and identified indisulam as a potent neuroblastoma inhibitor that selectively targets the RNA splicing factor RBM39. To investigate the molecular mechanism of indisulam, I utilized a range of analytical and biological techniques, including LC-MS and GC-MS profiling, stable isotope tracing, RNA interference, cell respiratory and energetic assays and CRISPR-Cas9 gene editing.
I found that indisulam initiates the proteasomal degradation of RBM39 via DCAF15-E3 ubiquitin ligase, resulting in subsequent mis-splicing events and metabolic alterations in neuroblastoma cells. I characterized the metabolic response of DCAF15 knockout lines and identified potential contributory effects to indisulam toxicity and concluded that the main determinant of metabolic effects in neuroblastoma is RBM39 degradation, similar to colorectal and lymphoid cancers.
Furthermore, I investigated the efficacy of indisulam in neuroblastoma cell models and correlated the expression of DCAF15 with reduced cell viability. I determined the molecular targets of RBM39 proteasomal degradation responsible for metabolic alterations in neuroblastoma and identified consistent effects of indisulam on metabolism, including to glutamine utilization which can contribute to toxicity independently of RBM39 degradation. I also found that MYCN expression sensitizes neuroblastoma to indisulam treatment which should be considered in therapy.
In conclusion, the findings of this work suggest that dual inhibition of RNA splicing and metabolism by indisulam is a promising therapeutic approach for the treatment of high-risk neuroblastoma and the analytical techniques employed in this study provide important insights into the molecular mechanisms underlying this approach.
I found that indisulam initiates the proteasomal degradation of RBM39 via DCAF15-E3 ubiquitin ligase, resulting in subsequent mis-splicing events and metabolic alterations in neuroblastoma cells. I characterized the metabolic response of DCAF15 knockout lines and identified potential contributory effects to indisulam toxicity and concluded that the main determinant of metabolic effects in neuroblastoma is RBM39 degradation, similar to colorectal and lymphoid cancers.
Furthermore, I investigated the efficacy of indisulam in neuroblastoma cell models and correlated the expression of DCAF15 with reduced cell viability. I determined the molecular targets of RBM39 proteasomal degradation responsible for metabolic alterations in neuroblastoma and identified consistent effects of indisulam on metabolism, including to glutamine utilization which can contribute to toxicity independently of RBM39 degradation. I also found that MYCN expression sensitizes neuroblastoma to indisulam treatment which should be considered in therapy.
In conclusion, the findings of this work suggest that dual inhibition of RNA splicing and metabolism by indisulam is a promising therapeutic approach for the treatment of high-risk neuroblastoma and the analytical techniques employed in this study provide important insights into the molecular mechanisms underlying this approach.
Version
Open Access
Date Issued
2022-04
Date Awarded
2023-09
Copyright Statement
Creative Commons Attribution NonCommercial NoDerivatives Licence
Advisor
Keun, Hector
Nijhuis, Anke
Nicholson, Jeremy
Publisher Department
Department of Surgery & Cancer
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)