Discovery of novel pyrazolo[1,5-a]pyrimidine derivatives as selective ROCK2 inhibitors with anti-breast cancer migration and invasion activities

Rho-associated coiled-coil kinase (ROCK) is involved in multiple cellular activities regulating the actin Cytoskeleton, such as cell morphology, adhesion, and migration. The inhibition of ROCK is a feasible strategy to suppress breast Cancer metastasis. Herein, based on Belumosudil, a series of pyrazolo[1,5-a]pyrimidine derivatives as selective ROCK2 inhibitors were designed and synthesized. Through systematic investigation of SARs, the piperazine analog 7u was identified with optimum ROCK2 inhibitory activity (IC₅₀ = 36.8 nM) and excellent selectivity over the isoform protein ROCK1 (>250-fold). Intriguingly, upon treatment with 7u, the arrangement of the MDA-MB-231 Cytoskeleton was affected accompanied by the alteration of morphology. Furthermore, cell scratch and transwell assays indicated that 7u inhibited MDA-MB-231 cell migration and invasion in a dose-dependent manner. Ultimately, the binding model of 7u with ROCK2 well accounted for the superior activities of 7u as a promising ROCK2 Inhibitor with the potential application in breast Cancer metastasis treatment.

Breast cancer metastasis; Inhibitors; Pyrazolo[1,5-a]pyrimidine; ROCK2; Synthesis.