Pharmacological investigations into matrix metalloproteinase-activated anti-tumour prodrugs. In vitro metabolic and pharmacological investigations into a series of colchicine-based peptide prodrugs activated by tumour-expressed matrix metalloproteinases

Matrix metalloproteinases (MMPs) play a significant role in degrading the extra- cellular matrix in cancer development and metastasis. Overexpression of matrix metalloproteinases in tumour tissues relative to normal tissues has been exploited as a target for peptide-based therapeutics, to improve therapeutic index of currently used agents. The stability of MMP-activated prodrugs in normal tissue or organs is a significant challenge for their success in the clinic. In an in vitro study, the stability of twenty six prodrugs was studied in mouse liver, kidney, lung and tumour homogenates using HPLC and LC/MS. Selected agents were studied in vivo. Each prodrug has a characteristic amino acid sequence with dominant FITC N-terminal end cap. All prodrugs were conjugated to a colchicine derivative (ICT 2552) which is a vascular disrupting agent causing tumour vasculature shutdown and consequently, tumour necrosis. ICT 3146, ICT 3019, ICT 3120 and ICT 3115 prodrugs showed significant stability in normal tissues and considerable activation in certain tumour tissues compared to the lead compound ICT 2588. Also, the selectivity of promising prodrugs to the MMP family was confirmed by using leupeptin (serine, cysteine and threonine protease inhibitor), pepstatin A (aspartate protease inhibitor), phosphoramidon (nepralysin inhibitor), ilomastat (metalloproteinase inhibitor) and BML-P115 (matrix metalloproteinase inhibitor). Moreover, members of the MMP family responsible for cleaving the selected prodrugs were identified using recombinant MMP enzymes. Furthermore, a LC/MS-MS method was developed to specifically detect and quantify MMP-16 protein expression in H460 tumour. MMP- 16 was responsible for the cleavage of ICT 3146 and ICT 3115. Therefore, MMP-activated prodrugs could be a useful therapeutic approach to avoid off-site toxicities of currently used anti-tumour agents.

Grantor dc:publisher.institution

University of Bradford

Year dc:date.issued

2014

Author dc:creator

• Youssef, Ahmed M.M.

Advisors dc:contributor.advisor

• Loadman, Paul
• Falconer, Robert A.

• Matrix Metalloproteinases; Membrane Type Matrix Metalloproteinases; Cancer; Prodrug; Drug metabolism; Colchicine; Peptide-based therapeutics

Statement dc:rights

• <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nc-nd/3.0/88x31.png" /></a><br />The University of Bradford theses are licenced under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/">Creative Commons Licence</a>.

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10454/13982

OAI identifier oai:identifier

oai:bradscholars.brad.ac.uk:10454/13982