Post-translational modifications in drug resistance

Recent developments in the utilization of pyridones as privileged scaffolds in drug discovery

INTRODUCTION

Pyridones are six-membered, nitrogen-containing heterocycles, possessing two isomeric forms; these are 2-pyridones and 4-pyridones. Both pyridone rings display unique physicochemical properties including weak alkalinity and dual hydrogen-bond donor/acceptor propensities. These heterocyclic compounds are particularly underlined for their diverse biological effects, including their cytotoxicity activity as well as their antibacterial, antiviral, anti-inflammatory, and anti-fibrotic properties. This versatility has attracted remarkable interest and held promise for addressing the challenges of drug resistance.

AREA COVERED

This review is the outcome of literature searches conducted on articles published between 2022 and 2025 across several major databases, including PubMed, Scopus, and Web of Science, using specific keywords concerning 'pyridone' and 'bioactivity.' It focuses on the identification of therapeutic targets, the process of molecular mechanisms, and the plausible modes of interaction and binding.

EXPERT OPINION

Pyridones have been reported to exhibit a wide range of bioactivities by regulating critical signaling pathways that have a diverse influence on downstream gene expression, intracellular enzyme activity and cytoskeletal configuration. They are consequently used as privileged fragments in the design of biologically active molecules with promising application value in pharmaceutical chemistry. Further investigation will be required to enhance drug-like properties. Continuous progress in structure optimization and clinical trial results will help to provide a guideline for future drug candidate discovery.

ML210 Antagonizes ABCB1- Not ABCG2-Mediated Multidrug Resistance in Colorectal Cancer

Objectives: ABCB1-mediated multidrug resistance (MDR) compromises chemotherapy efficacy in colorectal cancer (CRC). Despite decades of research, no selective ABCB1 inhibitor has achieved clinical success. This study investigates ML210 as a novel ABCB1-specific inhibitor to reverse ABCB1-driven MDR. Methods: Cytotoxicity assays (MTT) were performed on ABCB1-overexpressing HCT-8/V and ABCG2-overexpressing S1-M1-80 CRC cells. Drug accumulation (doxorubicin/mitoxantrone) was quantified via flow cytometry, and cell cycle effects were analyzed using propidium iodide staining. Molecular docking utilized the ABCB1 crystal structure. Results: ML210 selectively reversed ABCB1-mediated resistance to doxorubicin and vincristine in HCT-8/V cells, enhancing intracellular drug accumulation without affecting ABCG2 activity. It induced cell cycle arrest in ABCB1-overexpressing cells and did not alter ABCB1 protein expression. Molecular docking revealed stable binding of ML210 within the ABCB1 substrate pocket through hydrophobic interactions and hydrogen bonding. Conclusions: ML210 is a selective ABCB1 inhibitor that circumvents MDR via direct transport blockade, offering a targeted strategy against ABCB1-mediated chemoresistance in CRC. Its specificity for ABCB1 over ABCG2 highlights potential clinical advantages.