Abstract 1377: Identification and characterization of small molecule inhibitors of the activator protein-1 pathway

Abstract

Abstract The activation of transcription factor activator protein-1 (AP-1) plays a critical role in multiple stages associated with carcinogenesis. The AP-1 complex is a dimeric transcription factor typically made up of proteins from JUN, FOS, ATF, and MAF families. Growth factors including EGF activate AP-1 via cell surface receptors such as EGF receptor (EGFR). EGFR activation of MAPK cascades lead to phosphorylation and nuclear translocation of AP-1 subunits. Discovery of selective inhibitors of the AP-1 pathway would lead to invaluable tools in the study, treatment and prevention of multiple cancers. To screen for AP-1 pathway inhibitors, a FRET-based AP-1 β-lactamase reporter was used to measure AP-1 activation in a ME-180 cervical cancer cell line. Approximately 75,000 compounds were screened, each at 7-15 concentrations, in a quantitative high-throughput screening (qHTS) format. Several novel structure series were identified from this screen. Hits selected based on a structure-activity relationship analysis were confirmed and further investigated for mechanism of action because EGF-stimulated AP-1 activation can be inhibited by multiple mechanisms in the pathway. Inhibitors mechanisms of action in the EFGR-mediated pathway were determined in follow-up studies including receptor inhibition, MAPK inhibition, and direct disruption of the AP-1 signaling complex. The identification and characterization of novel AP-1 inhibitors will lead to compounds that serve as probes of the AP-1 pathway and potential candidates for anticancer drug development. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1377. doi:10.1158/1538-7445.AM2011-1377