Use this URL to cite or link to this record in EThOS:
Title: Enhancing the delivery of therapeutic cargo to cancer cells using cell penetrating peptides
Author: Eissa, Noura Gamal
ISNI:       0000 0004 5919 6351
Awarding Body: Cardiff University
Current Institution: Cardiff University
Date of Award: 2015
Availability of Full Text:
Access from EThOS:
Access from Institution:
Cell penetrating peptides (CPPs) have received considerable attention as cellular delivery vectors for small-molecule and macromolecular therapeutics. Hundreds of CPP sequences have now been described including bioportides that serve as single entity modifiers of cell physiology. Translation of promising CPP pre-clinical studies have however been disappointing as few identified delivery-systems have progressed to clinical trials. This project aimed to extend on studies using CPPs for delivering peptides influencing NF-B signalling and to search for novel membrane active peptides that could be classed as CPPs or bioportides. In-house methods measuring IB-α degradation and luciferase expression assays were developed to study the capacity of penetratin to influence NF-B activity via delivery of the NBD peptide (Pen-NBD: DRQIKIWFQNRRMKWKKTALDWSWLQTE). Results from these studies highlighted how two methods investigating the same signalling pathway could give very different results. Pen-NBD did not reduce TNF-α-induced IB-α degradation but induced reduction in TNF-α-induced luciferase activity. This effect was also observed in cells treated with penetratin alone or DMSO- diluent. EJP-18 (LFMRRRHIVRKRTLRRLL) represents a novel peptide from the EGFR juxtamembrane region and was found to be membrane active and internalised into cells. This thesis further characterised this peptide including two other sequences from this region of EGFR (EJP-21- ii LFMRRRHIVRKRTLRRLLQER and E-64562- RRRHIVRKRTLRRLLQER). In studied cancer cell lines, EJP-18 was toxic in an EGFR-dependant manner and aside from being a potential bioportide, also effectively delivered protein (BSA) and siRNA into cells. EJP-18/BSA was delivered to the lysosome and it remains to be determined whether it could be utilised to deliver siRNA to the cytosol. Cytotoxicity and protein delivery studies with EJP-21 and E-64562 highlighted the critical importance of terminal hydrophobicity in the EJP-18 sequence; this may extend to other studies involving CPPs. This thesis provides new information on in vitro activity of CPPs and CPP-chimeras. Additionally, new peptides were discovered that could potentially be classed as bioportides and CPPs.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: RM Therapeutics. Pharmacology