Optimization of a Pipemidic Acid Autotaxin Inhibitor

Abstract

Autotaxin (ATX, NPP2) has recently been shown to be the lysophospholipase D responsible for synthesis of the bioactive lipid lysophosphatidic acid (LPA). LPA has a well-established role in cancer, and the production of LPA is consistent with the cancer-promoting actions of ATX. Increased ATX and LPA receptor expression have been found in numerous cancer cell types. The current study has combined ligand-based computational approaches (binary quantitative structure-activity relationship), medicinal chemistry, and experimental enzymatic assays to optimize a previously identified small molecule ATX inhibitor, H2L 7905958 (1). Seventy prospective analogs were analyzed via computational screening, from which 30 promising compounds were synthesized and screened to assess efficacy, potency, and mechanism of inhibition. This approach has identified four analogs as potent as or more potent than the lead. The most potent analog displayed an IC(50) of 900 nM with respect to ATX-mediated FS-3 hydrolysis with a K(i) of 700 nM, making this compound approximately 3-fold more potent than the previously described lead.

Hits of a High-Throughput Screen Identify the Hydrophobic Pocket of Autotaxin/Lysophospholipase D As an Inhibitory Surface

“…The differences in substrate-specific inhibition by the two groups of compounds led us to hypothesize that they might interact with different surfaces of ATX, as has been suggested for other ATX inhibitors showing substrateselective effects (Hoeglund et al, 2010). Computational docking studies were performed using one of the recently solved crystal structures of ATX (2XR9) (Fig.…”

“…Inhibition of ATXmediated hydrolysis of various chain-length LPC substrates was determined via Amplex Red choline release assay as described previously (Hoeglund et al, 2010;North et al, 2010). Briefly, 60-ml triplicate reaction volumes were loaded into 96-well, half-area plates (Corning Inc., Corning, NY) in assay buffer consisting of 50 mM Tris, 5 mM CaCl 2 , and 30 mM fatty acid-free BSA (pH 7.4).…”

“…At the present time there is no approved ATX inhibitor available for therapy; however, development of ATX inhibitors has gained increasing interest with several smallmolecule ATX inhibitors having been described (Ferry et al, 2008;Saunders et al, 2008;Albers et al, 2010;Gierse et al, 2010;Hoeglund et al, 2010;Mize et al, 2011;Gotoh et al, 2012;Kawaguchi et al, 2013;St-Coeur et al, 2013). A considerable amount of effort has been devoted to the characterization of inhibitors that interact with the active site of ATX.…”

Computational Methods in Drug Discovery

“…The study resulted in the identification of 18 novel CPEs, four of which showed minimal or no toxic effects (Golla et al, 2012). Hoeglund et al (2010) used QSAR modeling combined with synthetic optimization in a follow up to their most potent hit from a 2008 in silico screen for inhibitors of autotaxin. Autotaxin is an autocrine motility factor and has been linked to cancer progression, multiple sclerosis, obesity, diabetes, Alzheimer's disease, and chronic pain through the production of lysophosphatidic acid (LPA) (Kawagoe et al, 1997;Euer et al, 2002;Baumforth et al, 2005;Boucher et al, 2005;Umemura et al, 2006;Inoue et al, 2008).…”

A Bromophosphonate Analogue of Lysophosphatidic Acid Surpasses Dacarbazine in Reducing Cell Proliferation and Viability of MeWo Melanoma Cells

“…Recent studies have shown that targeting either the LPA3 receptor or ATX effectively reduces melanoma cell viability (Altman et al 2010). Furthermore, research devoted to producing inhibitors and antagonists targeting the ATX-LPA receptor axis has yielded a large variety of compounds (Albers, Dong et al 2010;Altman et al 2010;Baker, Fujiwara et al 2006;Block, Duff et al 2010;Hoeglund, Bostic et al 2010;North, Howard et al 2010;Xu, Yang et al 2009), suggesting the critical role of this pathway in cancer. Herein we tested the in vitro capability of another antagonist of the LPA3 receptor and the lysophospholipase D activity of autotaxin, BrP-LPA, among the MeWo melanoma cell line.…”