Polo-like Kinase 1 (PLK1) Inhibitors Targeting Anticancer Activity

Polo-like kinase 1 (PLK1) is a serine/threonine kinase that orchestrates multiple critical events during mitosis, including centrosome maturation, spindle assembly, kinetochore–microtubule attachment, and cytokinesis. Dysregulation and overexpression of PLK1 are frequently observed in various cancers, correlating with increased proliferation, metastatic potential, and poor prognosis, which highlights its potential as a therapeutic target. Traditional small-molecule inhibitors have predominantly focused on the ATP-binding site of the N-terminal kinase domain, effectively inducing mitotic arrest and apoptosis in tumor cells; however, these compounds often suffer from limited selectivity and off-target toxicity. The C-terminal Polo-box domain (PBD), responsible for substrate recognition and subcellular localization, has emerged as an alternative and highly selective target for inhibitor design, enabling the disruption of protein–protein interactions critical for PLK1 function. Here, we present a comprehensive review demonstrating the potential inhibition of several compounds against PLK1. This work establishes a foundation for future preclinical development of small molecule-based therapeutics against PLK1-dependent malignancies.