Rational Design of 6-Amino-2-Piperazinylpyridine-Based ROCK2 Inhibitors With Anti-Breast Cancer Metastatic Efficiency.

Rho-associated coiled coil kinase (ROCK) plays a pivotal role in regulating actin cytoskeleton remodeling and cellular motility, establishing it as a promising therapeutic target for metastatic breast cancer. Guided by the lead compound belumosudil, a novel series of ROCK2 inhibitors based on a 6-amino-2-piperazine pyridine scaffold was designed and synthesized. The Kinase-Glo assay identified compound 14r as the most potent analog, showing an IC₅₀ value of 82.6 nM, which represented a 1.2-fold improvement over belumosudil. Furthermore, the morphology of MDA-MB-231 cells treated with 14r was significantly changed in immunofluorescent staining analysis. Simultaneously, cell scratch experiments showed that 14r inhibited the migration of MDA-MB-231 cells in a dose-dependent manner. Additionally, molecular docking studies elucidated the binding mode of 14r within the ROCK2 ATP pocket, corroborating its nanomolar-level inhibitory activity. In conclusion, 14r showed great potential for further optimization to suppress breast cancer metastasis.