Motivation: Computational techniques have been applied to experimental datasets to identify drug mode-of-action. A shortcoming of existing approaches is the requirement of large reference databases of compound expression profiles. Here, we developed a new pathway-based compendium analysis that couples multi-timepoint, controlled microarray data for a single compound with systems-based network analysis to elucidate drug mechanism more efficiently.
Results: We applied this approach to a transcriptional regulatory footprint of phthalimide neovascular factor 1 (PNF1)-a novel synthetic small molecule that exhibits significant in vitro endothelial potency-spanning 1-48 h post-supplementation in human micro-vascular endothelial cells (HMVEC) to comprehensively interrogate PNF1 effects. We concluded that PNF1 first induces tumor necrosis factor-alpha (TNF-alpha) signaling pathway function which in turn affects transforming growth factor-beta (TGF-beta) signaling. These results are consistent with our previous observations of PNF1-directed TGF-beta signaling at 24 h, including differential regulation of TGF-beta-induced matrix metalloproteinase 14 (MMP14/MT1-MMP) which is implicated in angiogenesis. Ultimately, we illustrate how our pathway-based compendium analysis more efficiently generates hypotheses for compound mechanism than existing techniques.