Discovery and biological evaluation of biaryl acetamide derivatives as selective and in vivo active sphingosine kinase-2 inhibitors

Sphingosine kinase 2 (SphK2) has emerged as a promising target for cancer therapy due to its critical role in tumor growth. However, the lack of potent and selective inhibitors has hindered its clinical application. Herein, we report the design and synthesis of a series of novel SphK2 inhibitors, culminating in the identification of compound 12q as a highly selective and potent inhibitor of SphK2. Molecular dynamics simulations suggest that the incorporation of larger substitution groups facilitates a more effective occupation of the binding site, thereby stabilizing the complex. Compared to the widely used inhibitor ABC294640, compound 12q exhibits superior anti-proliferative activity against various cancer cells, inducing G2 phase arrest and apoptosis in liver cancer cells HepG2. Notably, 12q inhibited migration and colony formation in HepG2 and altered intracellular sphingolipid content. Moreover, intraperitoneal administration of 12q in mice resulted in decreased levels of S1P. 12q provides a valuable tool compound for exploring the therapeutic potential of targeting SphK2 in cancer.