Is Aurora Kinase C a Proto-Oncogene?

Aurora kinases are the key regulators of cell cycle progression. Aurora-A and Aurora-B, expressed in somatic cells and are involved mainly in mitosis. Aurora-C is mainly expressed during gametomatogenesis and is involved in meiosis. Aurora-C is hardly detectable in normal somatic cells. The kinases are overexpressed in many cancer lines. Aurora-A possesses an oncogenic activity while Aurora-B does not. We investigated whether Aurora-C possesses such an oncogenic activity. We report that overexpression of Aurora-C induces abnormal centrosome amplification and multinucleation. The stable NIH3T3 cell clones overexpressing active Aurora-C formed foci of colonies when grown on soft agar, indicating that a gain of Aurora-C activity is sufficient to transform cells. We also reported that stable cell lines overexpressing Aurora-C induced tumour formation when injected into nude mice and abnormal mitosis along cell cycle, demonstrating the oncogenic activity of active Aurora kinase C. Interestingly enough tumour aggressiveness was positively correlated with the quantity of of active kinase, making Aurora C potentiaal anti cancer therapeutic agent.