Septins disruption controls tumor growth and enhances efficacy of Herceptin

Septin expressions are altered in cancer cells and exhibit poor prognoses in malignancies. As the first approach to develop a septin filament targeting agent, we optimized the structure of Forchlorfenuron (FCF), a known plant cytokinin to generate UR214-9, which contrary to FCF, causes septin-2/9 filamental structural catastrophe in cancer cells without altering cellular septin protein levels. In-silico docking using septin-2/septin-2 dimer complex showed that UR214-9 displaced the guanine carbonyl oxygen from the GDP binding domain and showed increased binding energy than FCF(−8.59vs-7.21). UR214-9 reduced cancer cell growth, downregulated HER2/STAT-3 axis and controlled growth of HER2+ pancreatic, breast and ovarian cancer xenografts in NSG mice and enhanced response of Herceptin against HER2+breast cancer xenograft. Transcriptome analysis of UR214-9 exposed cells demonstrated significant perturbation of 1200 genes in JIMT-1 breast cancer cells indicating target specificity and non-transcriptional functions of UR214-9. In summary, disrupting septins via UR214-9 is a new approach to control the growth of HER2+ malignancies.