The protein kinase Aurora-A is a major regulator of the cell cycle that 
orchestrates mitotic entry and is required for the assembly of a functional 
mitotic spindle. Overexpression of Aurora-A has been strongly linked with 
oncogenesis and this has led to considerable efforts at therapeutic targeting of 
the kinase activity of this protein. However, the exact mechanism by which 
Aurora-A promotes oncogenesis remains unclear. Here, we show that Aurora-A 
modulates the repair of DNA double-strand breaks (DSBs). Aurora-A expression 
inhibits RAD51 recruitment to DNA DSBs, decreases DSB repair by homologous 
recombination and sensitizes cancer cells to PARP inhibition. This impairment of 
RAD51 function requires inhibition of CHK1 by Polo-like kinase 1 (PLK1). These 
results identify a novel function of Aurora-A in modulating the response to DNA 
DSB that likely contributes to carcinogenesis and suggest a novel therapeutic 
approach to the treatment of cancers overexpressing this protein.