Bacteriophage-mediated systemic gene therapy of Diffuse Intrinsic Pontine Glioma through the blood-brain barrier
Author(s)
Yan, Wenqing
Type
Thesis
Abstract
Diffuse intrinsic pontine glioma (DIPG) is the most aggressive childhood brain tumour with a poor survival rate of only 6-10% beyond 2 years with no effective therapies. Surgical resection is not viable due to tumour location and existing treatments such as chemotherapy and radiotherapy show poor therapeutic response. We have applied a targeted cytokine gene therapy by using an engineered hybrid phagemid adeno-associated virus (PAAV) to selectively target the tumour through cancer-selective integrin binding ligand. This vector is derived from recombinant adeno-associated virus (AAV) DNA and M13-filamentous phage capsid and genetically engineered to display the RGD4C peptide which targets αvβ3 and αvβ5 integrin receptors that are over-expressed on tumour cells and tumour vasculature. The tumour necrosis factor-related apoptosis inducing ligand (TRAIL), which has preferential toxicity in tumour cells, was selected as the cytokine therapeutic gene to be delivered via this targeted vector (RGD4C/PAAV). We characterised 6 primary human DIPG cells obtained from biopsies grown under different culture conditions (adherent and spheroid) and evaluated the efficacy of PAAV-mediated TRAIL gene delivery in DIPG cells. We demonstrated that all 6 DIPG cell cultures express the αvβ3 and αvβ5 integrin receptors and TRAIL death receptors which are crucial for the success of our therapy. Next, we showed that our targeted RGD4C/PAAV vector was able to deliver the reporter gene Lucia (secreted luciferase) with high transduction efficacy. Next, we showed the transduction of HSJD-DIPG-07 DIPG cells with our prototype (RGD4C/PAAV-TRAIL) was able to induce significant DIPG cell death. Finally, the efficacy of our prototype was tested for the treatment of DIPG in vivo through intravenous administration. RGD4C/PAAV-TRAIL showed selective tumour homing and prolonged animal survival. In this thesis, we demonstrate that RGD4C/PAAV provides targeting of TRAIL expression selectively to the tumour environment, ensuring systemic safety and therapeutic efficacy.
Version
Open Access
Date Issued
2023-01-08
Date Awarded
2024-05-01
Copyright Statement
Attribution-NonCommercial 4.0 International Licence (CC BY-NC)
License URL
Advisor
Hajitou, Amin
Suwan, Keittisak
Sponsor
Children with Cancer UK
Grant Number
16-230
Publisher Department
Department of Medicine
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)