Identification of a Small Molecule That Induces Mitotic Arrest Using a Simplified High-Content Screening Assay and Data Analysis Method

Abstract

High-content screening has emerged as a newand powerful technique for identifying small-molecule modulators ofmammalian cell biology. The authors describe the development and execution of a high-content screen to identify smallmolecules that induce mitotic arrest in mammalian cancer cells. Many widely used chemotherapeutics, such as Taxol ®and vinblastine, induce mitotic arrest, and the creation of new drugs that also induce mitotic arrest may have tremendous therapeutic value. In their screen, the authors employed a simple DNA stain (DAPI) and a sensitive nonparametric statistical test to identify compounds from an internal collection of 13,000 high-quality lead-like small molecules. Subsequent analysis of 1 active compound indicated that it induces mitotic arrest, assessed using a high-content phosphohistone H3 detection assay, and caused cell proliferation defects inmultiple cancer cell lines. The active compound, a quinazolinone originating from a natural product-like subset of the screened compounds, is active in cells at 500nMand appears to act by inhibiting the polymerization of tubulin.