Thesis

Synthesis and evaluation of novel non-viral gene delivery systems for prostate cancer targeting

Creator
Rights statement
Awarding institution
  • University of Strathclyde
Date of award
  • 2018
Thesis identifier
  • T14845
Person Identifier (Local)
  • 201553754
Qualification Level
Qualification Name
Department, School or Faculty
Abstract
  • Prostate cancer is the second most widespread cancer in men worldwide. Treatment choices are limited to prostatectomy, hormonal and radiotherapy that commonly have deleterious side effects and vary in their efficacy, depending on the stage of the disease. Among novel experimental strategies, gene therapy holds great promise for the treatment of cancer, but its use is currently limited by the lack of delivery systems able to selectively deliver the therapeutic genes to the tumours after intravenous administration without major drawbacks. Given that lactoferrin receptors, prostate specific membrane antigen (PSMA) and integrins are overexpressed on prostate cancer cells, the purpose of this study is to determine whether lactoferrin, Peptide2 (CWQPDTAHHWATL) and Peptide4 (CPRPRGDNPPLTCGGKKK) bearing diaminobutyric polypropylenimine (DAB) based dendriplexs would improve the targeting of therapeutic genes in vitro and in vivo. The chemical and physical characteristics of the synthesised dendrimers were first determined, followed by various in vitro experiments, to assess the improvement in the transfection and cellular uptake of the modified dendriplexes in PC-3, DU145 and LNCaP prostate cancer cell lines. Finally, in vivo studies were carried out using BALB/c nude mice to investigate the anticancer effects of the Lf-bearing dendriplexes encoding TNFα, TRAIL, or IL-12. DAB-Lf significantly increased the cellular uptake of the DNA in all prostate cancer cells. The highest DNA uptake, observed in PC-3 cells, was double than that observed in cells treated with non-targeted dendriplex. The anti-proliferative efficacy of DAB-Lf dendriplex encoding TNFα, TRAIL, or IL-12 was significantly improved compared with unmodified DAB dendriplex. In vivo, intravenous injections of DAB-Lf dendrimer complexed with plasmid DNA encoding TNFα and TRAIL have resulted in complete regression in 70% and 40% of tumours respectively at the end of the experiment in tumour-bearing mice. DAB-PEG2k-Pep2 significantly improved the cellular uptake in LNCaP and DU145 cells, but not in PC-3 cells compared with the non-targeted dendriplex. The therapeutic DNA encoding TNFα was successfully transfected after complexation with DAB-PEG2k-Pep2 in all three cell lines, with significant variance in the cytokine concentration between cell lines. The IC50 of DAB-PEG2k-Pep2 dendriplex encoding TNFα was significantly improved compared with untargeted DAB-PEG dendriplex in LNCaP cells. In conclusion, DAB-Lf is a promising DNA carrier for targeting prostate cancer. This study is one of few showing significant tumour regression after intravenous administration of gene therapy using non-viral vectors as a single therapy approach. Peptide2 was also found to be an effective ligand for PSMA, however more improvement in the formulation is still required to obtain an enhanced therapeutic effect.
Advisor / supervisor
  • Dufès, Christine.
Resource Type
Note
  • This thesis was previously held under moratorium from 18th May 2018 until 18th May 2023
DOI
Date Created
  • 2018
Former identifier
  • 9912597791502996

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