A novel tubulin binding molecule drives differentiation of acute myeloid leukaemia cells

Acute Myeloid Leukaemia (AML) continues to have a poor prognosis, especially in the elderly. One reason for this is that many treatment regimens are not well tolerated by elderly patients. Much current focus is on the development of therapies that can target specific vulnerabilities of AML while having fewer toxic side effects. However, despite much recent progress in developing better drugs, many patients with AML still die within a year of diagnosis, partly due to the fact that it is difficult to identify therapeutic targets that are effective across multiple AML subtypes. One common factor across AML subtypes is the presence of a block in differentiation. Thus screening for compounds that can overcome this block in genetically diverse AML models should allow for the identification of agents that are not dependent on a specific mutation for their efficacy. Here, we used a phenotypic screen to identify novel compounds that stimulate differentiation in several AML cell lines. Lead compounds were shown to decrease tumour burden and to increase survival in vivo. Using multiple complementary target deconvolution approaches, these compounds were revealed to be anti-mitotic tubulin disruptors that cause differentiation by inducing a G2-M mitotic arrest. Together, these results reveal a novel function for tubulin disruptors in causing differentiation of AML cells.