Identification and validation of novel small molecule inhibitors targeting FoxM1-DNA binding domain with anti-cancer potential.

Abstract

The Forkhead box M1 (FoxM1) transcription factor is a well-established oncogenic driver, with its overexpression closely associated with tumor grade, aggressiveness and adverse clinico-pathological features across multiple cancer types. This has garnered considerable therapeutic interest in FoxM1 as a potential target. However, current FoxM1 inhibition strategies suffer from significant limitations or lack clinical validation. In the present study, we employed a structure based rational drug design approach to screen small molecule inhibitors targeting the FoxM1-DNA binding domain (FoxM1-DBD) using the NCI compound library. Selected lead compounds exhibited potent suppression of FoxM1and its targets in CaSki cervical cancer cells, outperforming conventional FoxM1 inhibitors. Electrophoretic Mobility Shift Assay (EMSA) and tryptophan specific fluorescence analyses confirmed direct and specific interaction of the compounds with FoxM1, resulting in effective disruption of FoxM1-DNA binding. Functional characterization revealed that these inhibitors robustly induced apoptosis as evidenced by enhanced PARP and caspase-7 cleavage. Furthermore, the lead compounds demonstrated activity across multiple cancer cell types and markedly attenuated key malignant traits of cancer cells, including proliferation, anchorage-independent growth, migration and invasion. Importantly, FoxM1 knockdown significantly diminished the tumor suppressive effects of the lead compounds thereby affirming target specificity. Collectively, our findings identify novel and selective small molecule inhibitors of FoxM1 that effectively disrupt FoxM1-driven oncogenic programs, highlighting their strong potential to evolve into credible anti-cancer therapeutics.