Abstract

Cancer is defined by an overexpression of cell-cycle regulators. Cytokinesis is a well conserved process which occurs at the final stage of cell mitosis. Understanding the relationship between cytokinesis and cancer is essential for developing targeted therapeutic strategies to mitigate uncontrolled cancer cell proliferation. Anillin, a key actin-binding protein, is one of the crucial regulators in cytokinesis. As anillin is upregulated in cancer cells, developing an anillin-specific inhibitor provides exceptional therapeutic potential for the treatment of cancer.
The objective of this project was to develop inhibitors that block anillin function. Anillin is activated upon binding to RhoA, with the binding interface mediated by key amino acid residues on two antiparallel α-helices in the RhoA–GTP binding domain (RBD) of anillin. Helical motifs are known to project the residues i, i + 4, and i + 7 on the same face of the α-helix. Previous research on α-helix mimetic compounds suggest substituted tri-aryl compounds can mimic the spatial arrangement of the i, i + 4, and i + 7 residues on an α-helix. Considering this, a library of tri-aryl compounds with functional groups that can bind to the respective residues on anillin was developed.
The compounds were synthesized by optimizing cross-coupling techniques previously employed, as well as carrying out various late-stage functional group transformations to ultimately expand the library of compounds, with isolated yields ranging from 21–99%. The compounds were characterized using 1H NMR, 13C NMR, as well as HRMS. Structure-activity-relationship (SAR) studies were conducted following a biomolecular fluorescence complementation (BiFC) assay performed by the collaborator, providing further insight into the key functional groups required to disrupt anillin activity. Blind docking studies were also carried out to assess potential bioactive conformations and binding pockets, and to compare the results with those obtained from the BiFC assay. Overall, this work lays the foundation for future efforts toward developing anillin inhibitors as potential anti-cancer therapeutics.