Roles of 14-3-3 eta in mitotic progression and its potential use as a therapeutic target for cancers

Abstract

14-3-3 proteins are involved in several cellular processes, including the G1/S and G2/M cell cycle transitions. However, their roles during mitosis are not well understood. Here, we showed that depletion of 14-3-3 eta, a 14-3-3 protein isoform, enhanced mitotic cell death, resulting in sensitization to microtubule inhibitors and inhibition of aneuploidy formation. The enhanced mitotic cell death by depletion of 14-3-3 eta appeared to be both caspase-dependent and independent. Furthermore, enhanced mitotic cell death and a reduction in aneuploidy following 14-3-3 eta depletion were independent of the mitotic checkpoint, which is thought to be the primary signaling event in the regulation of the cell death induced by microtubule inhibitors. When 14-3-3 eta depletion was combined with microtubule inhibitors in HCT116 and U87MG cells, it sensitized both cancer cell lines to microtubule inhibitors. These results collectively suggest that 14-3-3 eta may be required for mitotic progression and may be considered as a novel anti-cancer strategy in combination with microtubule inhibitors. Oncogene (2013) 32, 1560-1569; doi:10.1038/onc.2012.170; published online 7 May 2012