GSE132343
Suppression of FOXM1 Activities and Breast Cancer Growth in Vitro and in Vivo by a New Class of Compounds
The transcription factor FOXM1 is up-regulated and overexpressed in aggressive, therapy-resistant forms of hormone receptor-positive and triple negative breast cancers, and is associated with less good patient survival. FOXM1 pathway signaling is also a key driver in other aggressive cancers, including those in prostate, lung, ovary, and gastrointestinal tract. Therefore, our goal has been to identify compounds effective in suppressing FOXM1 activity and breast cancer proliferation, and displaying good potency and pharmacokinetic properties for in vivo antitumor efficacy. In this report, we describe our studies on the FOXM1 targeting activities of 1,1-diarylethylene mono- and diamine compounds and their methiodide salts in cell-free, cell-based, and in vivo assays. The compounds bind directly to FOXM1 and alter its proteolytic sensitivity, reduce the cellular level of FOXM1 protein, and suppress the proliferation of breast cancer cells. RNA-seq and gene set enrichment analyses indicate that the compounds NB-73 and NB-55 decrease the expression of FOXM1-regulated genes and suppress gene ontology processes known to be under FOXM1 regulation. Several compounds with favorable pharmacokinetic properties were studied in preclinical breast tumor models. One compound (NB-55) had good oral efficacy in suppressing the growth of FOXM1-containing breast tumors in NOD-SCID-gamma (NSG) mice, and several others (NB-73, NB-115, and NB-63) had good efficacy in tumor growth suppression by subcutaneous administration. Our findings identify and characterize a new class of compounds that effectively antagonize FOXM1 actions and tumor growth that may be suitable for further clinical evaluation in targeting aggressive breast cancers driven by FOXM1. Overall design: Examine the effects of various FOXM1 inhibitors on gene expression in both  estrogen receptor positive and triple negative breast cancer cell lines.