A study of the anti-invasive properties of N-α-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.

Peptide synthesis: chemical or enzymatic

“…is the modification of the peptide chain (backbone), which can be accomplished in different ways: its exchange by an amide analogue, the alkylation of the NH group of the peptide bond (Ahn et al 2002), the reduction of the carbonyl group of the peptide bond (Lozano et al 2004), or the exchange of the NH group of a peptide bond by an oxygen atom (depsipeptide) (Kuisle et al 1999;Albericio et al 2005;Cruz et al 2006) a sulfur atom (thioester) (Vabeno et al 2004) or a CH 2 group (ketomethylene isostere) (Martin et al 2001). Notable among these modified peptides are depsipeptides that are compounds having sequences of amino and hydroxy carboxylic acid residues regularly alternating; they can also form cyclic structures named cyclodepsipeptides, where the residues are connected in a ring.…”

Synthesis and cytotoxic activity of new 2‐[(3‐aminopropyl)dimethylsilyl]‐5‐triethylsilylfurans

“…[1] The fragment analysis [2] of clinically used antineoplastic agents shows that in many cases a heterocyclic amino group has been introduced to increase the solubility and bioavailability of the active substance, e.g. piperidine in Arzoxifene [3 -6] , Flavopiridol [7] and Perifosine, [8 -10] morpholine in Canertinib, [11,12] Gefinitib [13 -15] and Mofarotene, [16] thiomorpholine in Prinomastat, [17] piperazine in Dasatinib [18] and Imatinib, [19,20] and pyrrolidine in Idoxifene [21,22] . These heterocyclic amines are also used for formation of libraries of cytotoxic agents [23] .…”

Synthesis and antitumor activity of 3-[(methyl)bis(5-trialkylsilyl-furan-2-yl)silyl]propylamines

“…1 H NMR spectrum, , ppm (J, Hz): 0.39 (18H, s, 2Si(CH 3 ) 3 ); 0.71-0.72 (3H, d, J = 4.0, SiHCH 3 ); 5.08-5.11 (1H, m, SiH); 6.73 (2H, d, J = 3.6, 2H-3); 6.88 (2H, d, J = 3.6, 2H-4). Mass spectrum, m/z (I rel , %): 322 [M] + (39), 307 [MMe] +(18), 207 (37), 183(17), 159 (50), 146(22), 133 (62), 109(18), 96(16), 73 (100), 59(22).N,N-Diethyl-{3-[(methyl)bis(5-trimethylsilylfuran-2-yl)silyl]propyl}amine (2).Compound 1 (0.20 g, 0.62 mmol), N,N-diethylallylamine (0.07 g, 0.62 mmol), and two drops of 0.1% H 2 PtCl 6 ·6H 2 O solution in 2-PrOH were added to a flask equipped with reflux condenser and magnetic stirrer and heated for 1 h at 70ºC. The reaction course was monitored by GC-MS.…”