|200P London, UK
Structure-activity relationship of a novel family of cysteinyl leukotriene receptor antagonist quinoline compounds with anti-angiogenic activity.
Introduction: Previously, we identified quininib (2-[(E)-2-(quinolin-2-yl)vinyl]phenol), a cysteinyl leukotriene receptor antagonist with anti-angiogenic and anti-permeable activity (1,2). Here, we report a structure activity relationship study to more comprehensively characterise features which confer anti-angiogenic activity.
Methods: 70 quininib analogues were synthesised or purchased (3). Anti-angiogenic activity was ranked based on ability of 10 µM compound to inhibit blood vessel formation in two in vivo developmental angiogenesis assays in Tg[fli1:EGFP] zebrafish (i) hyaloid/ocular vessel formation and (ii) intersegmental /tail vessel formation. Compounds were considered active where ≥40% inhibition was observed compared to control. Selected highly ranked compounds were tested in human endothelial cell lines (HMEC-1) for cytoxicity (MTT assay) and anti-angiogenic activity (in vitro tubule formation assay). Efficacy was also determined in mouse aortic ring assay (4). CYSLT receptor antagonism was quantified using reporter cell bioassays.
Results: 18 analogues showed ≥40% inhibition in formation of hyaloid vessels and fourteen showed ≥40% inhibition in formation of intersegmental vessels. These compounds comprised those with “triene” bond and benzene ring modifications. Six compounds were selected for further testing (Q8: (E)-2-(2-Quinolin-2-yl-vinyl)benzene-1,4-diol HCl; Q 14: 3-(2-Quinolin-2-yl-ethyl)-phenol HCl; Q 18: 2-[(Z)-2-(Quinolin-2-yl)vinyl]phenol HCl; Q 20: (E)-2-(2-Quinolin-2-yl-propenyl)-phenol HCl; Q 22: 2-Quinolin-2-yl-ylethynyl-phenol HCl and Q 54: 2-(2-(2-Methoxyphenyl)vinyl)quinoline). No compound showed an effect on cell viability. Three compounds (Q 8, Q 18, Q 22) showed ≥40% reduction in in vitro tubule length and Q 18 showed ≥40% reduction in sprout formation in the aortic ring assay. Cell bioassays showed all six compounds inhibited LTD4 induced activation of CYSLT1 (IC50: 1.7 - 6.7 µM) and at 30 µM, four compounds (Q 14, Q 18, Q 20, Q 22) showed ≥50% inhibition of LTC4 induced activation of CYSLT2.
Conclusions: More than 10 compounds showed robust anti-angiogenic activity in both assays. Three quinoline compounds demonstrated anti-angiogenic activity in human cell lines and mouse aortic ring. This study is the first step in identifying a quinoline pharmacophore for antagonism of the CYSLT pathway as a therapeutic target for inhibiting the aberrant pathological angiogenesis occurring in blindness, cancer and arthritis.
1. Galvin O et al., (2016). J Control Release 233, 198-207.
2. Reynolds AL et al., (2016). J Biol Chem 291, 7242-7255.
3. Kennedy BN et al., (2016) USPTO US 9,388,138 B2 (Patent).
4. Baker M et al., (2012) Nat. Protoc 7, 89-104.