Development of a Novel Class of Mitochondrial Ubiquinol–Cytochrome <i>c</i> Reductase Binding Protein (UQCRB) Modulators as Promising Antiangiogenic Leads

Recently, we identified a novel therapeutic target and a small molecule for regulating angiogenesis. Our study showed that ubiquinol–cytochrome <i>c</i> reductase binding protein (UQCRB) of the mitochondrial complex III plays a crucial role in hypoxia-induced angiogenesis via mitochondrial reactive oxygen species (ROS) mediated signaling. Herein, we developed new synthetic small molecules that specifically bind to UQCRB and regulate its function. To improve the pharmacological properties of 6-((1-hydroxynaphthalen-4-ylamino)­dioxysulfone)-2<i>H</i>-naphtho­[1,8-<i>bc</i>]­thiophen-2-one (HDNT), a small molecule that targets UQCRB, a series of HDNT derivatives were designed and synthesized. Several derivatives showed a significant increase in hypoxia inducible factor 1α (HIF-1α) inhibitory potency compared to HDNT. The compounds bound to UQCRB and suppressed mitochondrial ROS-mediated hypoxic signaling, resulting in potent inhibition of angiogenesis without inducing cytotoxicity. Notably, one of these new derivatives significantly suppressed tumor growth in a mouse xenograft model. Therefore, these mitochondrial UQCRB modulators could be potential leads for the development of novel antiangiogenic agents

Discovery of Orally Available Runt-Related Transcription Factor 3 (RUNX3) Modulators for Anticancer Chemotherapy by Epigenetic Activation and Protein Stabilization

Recently, we identified a novel strategy for anticancer chemotherapy by restoring runt-related transcription factor 3 (RUNX3) levels via lactam-based histone deacetylase (HDAC) inhibitors that stabilize RUNX3. Described here are the synthesis, biological evaluation, and pharmacokinetic evaluation of new synthetic small molecules based on pyridone-based HDAC inhibitors that specifically stabilize RUNX3 by acetylation and regulate its function. Many of the newly synthesized compounds showed favorable RUNX activities, HDAC inhibitory activities, and inhibitory activities on the growth of human cancer cell lines. Notably, one of these new derivatives, (<i>E</i>)-<i>N</i>-hydroxy-3-(2-oxo-1-(quinolin-2-ylmethyl)-1,2-dihydropyridin-3-yl)­acrylamide (<b>4l</b>), significantly restored RUNX3 in a dose-dependent manner and showed high metabolic stability, a good pharmacokinetic profile with high oral bioavailability and long half-life, and strong antitumor activity. This study suggests that pyridone-based analogues modulate RUNX3 activity through epigenetic regulation as well as strong transcriptional and post-translational regulation of RUNX3 and could be potential clinical candidates as orally available RUNX3 modulators for the treatment of cancer

Property-Based Optimization of Hydroxamate-Based γ‑Lactam HDAC Inhibitors to Improve Their Metabolic Stability and Pharmacokinetic Profiles

Hydroxamate-based HDAC inhibitors have promising anticancer activities but metabolic instability and poor pharmacokinetics leading to poor in vivo results. QSAR and PK studies of HDAC inhibitors showed that a γ-lactam core and a modified cap group, including halo, alkyl, and alkoxy groups with various carbon chain linkers, improved HDAC inhibition and metabolic stability. The biological properties of the γ-lactam HDAC inhibitors were evaluated; the compound designated <b>8f</b> had potent anticancer activity and high oral bioavailability

Property-Based Optimization of Hydroxamate-Based γ‑Lactam HDAC Inhibitors to Improve Their Metabolic Stability and Pharmacokinetic Profiles

Hydroxamate-based HDAC inhibitors have promising anticancer activities but metabolic instability and poor pharmacokinetics leading to poor in vivo results. QSAR and PK studies of HDAC inhibitors showed that a γ-lactam core and a modified cap group, including halo, alkyl, and alkoxy groups with various carbon chain linkers, improved HDAC inhibition and metabolic stability. The biological properties of the γ-lactam HDAC inhibitors were evaluated; the compound designated <b>8f</b> had potent anticancer activity and high oral bioavailability