title: A study of the anti-invasive properties of N-alpha-phthalimidomethyl-ketomethylene tripeptide-based metalloprotease inhibitors.
abstract: We have developed matrix metalloprotease (MMP) inhibitors based on synthetic peptides incorporating a non-cleavable peptide-bond isostere at the site of the putative scissile bond. These inhibitors, N-alpha-phthaloyl-Gly-psi(CO-CH2)-Leu-Tyr-Ala-NH2 (Pht-G-CH2-LYA-NH2) and N-alpha-phthaloyl-Gly-psi(CO-CH2)-Leu-Tic-Ala-NH2 (Pht-G-CH2-LTcA-NH2) were kinetically evaluated against the type IV collagenases, gelatinase A (MMP-2) and B (MMP-9), and compared with an exactly analogous chelating-based inhibitor, N-alpha-mercaptoacetyl-Leu-Tyr-Ala-NH2 (HSCH2CO-LYA-NH2). The peptide inhibitors were also tested for their anti-invasive effects on breast carcinoma cell lines using a modification of the Boyden chamber assay. Gelatin zymography was utilized to identify gelatinolytic activities present in media removed from cultured breast cancer cells. Of the two N-alpha-phthalimidomethyl-ketomethylene peptide-based inhibitors, Pht-G-CH2-LYA-NH2 proved the more effective inhibitor of MMP-2 and MMP-9 (Ki 34.27 and 45.75 microM, respectively). However, when tested against two breast cancer cell lines, T47D and MDA-MB-231, both inhibitors were able to effectively reduce tumour cell invasion through a type IV collagen matrix by up to 91.2%. Of particular interest was the observation that Pht-G-CH2-LYA-NH2 was the most potent inhibitor of invasion by the highly aggressive MDA-MB-231 cells, despite the cells' relative lack of active secreted metalloprotease activity. The results obtained from this kinetic and anti-invasive analysis of the new inhibitors suggest that compounds incorporating the N-alpha-phthalimidomethyl-ketomethylene peptide-bond isostere may have potential for development as new agents with anti-metastatic properties.
authors: Division of Biomedicinal Chemistry, School of Pharmacy, The Queen's University of Belfast, Medical Biology Centre, Northern Ireland, UK. l.martin@qub.ac.uk
authors: S L
authors: SL
authors: Martin
authors: A
authors: A
authors: McDowell
authors: J F
authors: JF
authors: Lynas
authors: J
authors: J
authors: Nelson
authors: B
authors: B
authors: Walker
mesh_terms: D000465:Algorithms; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000201:enzymology; D017077:Culture Media, Conditioned; D004354:Drug Screening Assays, Antitumor; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D007700:Kinetics; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors*; D008855:Microscopy, Electron, Scanning; D009362:Neoplasm Metastasis / Q000517:prevention & control; D009374:Neoplasms, Experimental / Q000473:pathology; D010797:Phthalimides; D011480:Protease Inhibitors / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D017077:Culture Media, Conditioned; C429883:N-phthalimidomethyl-ketomethylene; D010797:Phthalimides; D011480:Protease Inhibitors; D008666:Metalloendopeptidases