Anticancer Activity of Indeno[1,2-b]-Pyridinol Derivative as a New DNA Minor Groove Binding Catalytic Inhibitor of Topoisomerase IIα

Computer-aided discovery of novel AMPK activators through virtual screening and SAR-driven synthesis

AMPK is a promising target for various chronic illnesses such as diabetes and Alzheimer's disease (AD). We sought to develop a novel small molecule that directly activates AMPK, with the potential to fundamentally modulate the pathogenic mechanisms of the metabolic disorders. To identify a potent novel pharmacophore in an unbiased way, we performed structure-based virtual screening on a commercially available chemical library, and evaluated the actual AMPK activity of 118 compounds selected from 100,000 compounds based on docking scores. Additional iterative molecular docking studies and experimental evaluation of AMPK activity led us to select a hit compound, B1, with a chromone backbone. Using the hit compound and other compounds structurally similar to the hit compound, we identified the chalcone structure as a new scaffold with more efficient interactions with key residues required for AMPK activation. From the newly designed and synthesized chalcone derivatives, we discovered compound 6 as a candidate compound. Compound 6 showed the most efficient interactions with the key residues of AMPK at in silico study and demonstrated significant activation of AMPK in both in vitro and in cellular assays.

AK-I-190, a New Catalytic Inhibitor of Topoisomerase II with Anti-Proliferative and Pro-Apoptotic Activity on Androgen-Negative Prostate Cancer Cells

Castration-resistant prostate cancer (CRPC) is a clinical challenge in treatment because of its aggressive nature and resistance to androgen deprivation therapy. Topoisomerase II catalytic inhibitors have been suggested as a strategy to overcome these issues. We previously reported AK-I-190 as a novel topoisomerase II inhibitor. In this study, the mechanism of AK-I-190 was clarified using various types of spectroscopic and biological evaluations. AK-I-190 showed potent topoisomerase II inhibitory activity through intercalating into DNA without stabilizing the DNA-enzyme cleavage complex, resulting in significantly less DNA toxicity than etoposide, a clinically used topoisomerase II poison. AK-I-190 induced G1 arrest and effectively inhibited cell proliferation and colony formation in combination with paclitaxel in an androgen receptor–negative CRPC cell line. Our results confirmed that topoisomerase II catalytic inhibition inhibited proliferation and induced apoptosis of AR-independently growing prostate cancer cells. These findings indicate the clinical relevance of topoisomerase II catalytic inhibitors in androgen receptor-negative prostate cancer.