A novel method of screening cell-cycle blockers as candidates for anti-tumor reagents using yeast as a screening tool.

The mechanisms of eukaryotic cell-cycle regulation are closely linked to cellular tumorigenesis. Compounds that affect the cell cycle are good candidates for developing anti-tumor drugs. We developed a screening method for cell-cycle blockers using a Saccharomyces cerevisiae cdc2-1 rad9Delta strain that can detect the activity of substances by cell growth. We performed screening on culture broth of various microbes, and identified five compounds, borrelidin, mycophenolic acid, UCS15A, copiamycin analog, and fredericamycin A, that were known to possess anti-tumor activity. These results indicate that this screening method is effective as a first-screening system for anti-tumor agents.