Abstract B131: Chemical array screen identifies a novel MMP inhibitor NPDK-18 that suppresses tumor cell migration

Abstract

Background and Purpose: Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases that degrade extracellular matrix components and that have been implicated in a wide range of pathological processes including tumor metastasis. Although many small-molecule MMP inhibitors have been developed, there are some problems related to specificity and side effects. In addition, recent studies have shown that several MMPs have nonproteolytic and tumor-suppressing functions depending upon the stage of cancer progression. Thus, much work remains for the elucidation of each MMP function and the development of new MMP inhibitors. Small-molecule microarrays represent a powerful new platform for facilitating target-based screens. Thousands of small molecules are arrayed on a slide glass and used to screen for protein-small molecule interactions in a high-throughput manner. We have developed unique photo-cross-linked chemical arrays, which enable the immobilization of a variety of small molecules on a solid support in a functional group-independent manner using a photoaffinity reaction. In this study, we screened MMP-9 inhibitors using the photo-cross-linked chemical arrays. Methods and Results: The array slides with compounds of the RIKEN NPDepo chemical library were probed sequentially with His-Myc-tagged human recombinant MMP-9, anti-His antibody, and a Cy5-labeled secondary antibody, and then scanned with a microarray scanner. The fluorescence signals from two slides treated with and without His-Myc-tagged MMP-9 were quantified. We obtained 27 hit compounds among 24,275 compounds; 2 of the identified compounds (isoxazole compound NPDK-1 and naphthofluorescein) inhibited MMP-9 enzyme activity in vitro. We further explored 17 analogs of NPDK-1 and found that NPDK-18 showed the strongest inhibitory activity against MMP-9, with an IC50 value of 3.8 μM. NPDK-18 inhibited the enzyme activities of MMP-2, MMP-12 and MMP-13, as well as MMP-9 and MMP-9/ΔHemopexin, with almost identical potency, but showed no inhibition against MMP-1 and MMP-7. The biological potency of NPDK-18 was confirmed in a wound-healing scratch assay, where NPDK-18 significantly inhibited cell migration of human fibrosarcoma HT1080 cells with no cell toxicity at 10 μM. Conclusion: These results suggest that NPDK-18 is a broad-spectrum MMP inhibitor. Our study has shown that the photo-cross-linked chemical arrays are useful for high-throughput drug screening. Citation Format: Makoto Kawatani, Yasumitsu Kondoh, Kaori Honda, Tomomi Sekine, Hiroyuki Osada. Chemical array screen identifies a novel MMP inhibitor NPDK-18 that suppresses tumor cell migration. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B131.