TH-257

TH-257 is a potent and selective small molecule inhibitor of LIM domain kinases 1 and 2 (LIMK1 and LIMK2). It acts by blocking the ATP-binding site of these kinases, thereby preventing the phosphorylation of their downstream substrate, cofilin. In the context of oncology, particularly acute myeloid leukemia (AML), TH-257 has been investigated for its ability to disrupt the RhoC-LIMK-cofilin signaling axis, which is involved in actin cytoskeleton remodeling and the formation of tunneling nanotubes. By inhibiting this pathway, TH-257 impairs horizontal mitochondrial transfer (HMT) from bone marrow macrophages to AML cells, a process that typically confers chemoprotection. Consequently, TH-257 treatment has been shown to restore the sensitivity of AML cells to chemotherapy agents such as daunorubicin in preclinical models.