Published online Nov 26, 2015. doi: 10.4331/wjbc.v6.i4.346
Peer-review started: April 14, 2015
First decision: May 13, 2015
Revised: September 18, 2015
Accepted: October 12, 2015
Article in press: October 13, 2015
Published online: November 26, 2015
Cyclin A2 is an essential regulator of the cell division cycle through the activation of kinases that participate to the regulation of S phase as well as the mitotic entry. However, whereas its degradation by the proteasome in mid mitosis was thought to be essential for mitosis to proceed, recent observations show that a small fraction of cyclin A2 persists beyond metaphase and is degraded by autophagy. Its implication in the control of cytoskeletal dynamics and cell movement has unveiled its role in the modulation of RhoA activity. Since this GTPase is involved in both cell rounding early in mitosis and later, in the formation of the cleavage furrow, this suggests that cyclin A2 is a novel actor in cytokinesis. Taken together, these data point to this cyclin as a potential mediator of cell-niche interactions whose dysregulation could be taken as a hallmark of metastasis.
Core tip: Cyclin A2, as an essential regulator of the cell division cycle, is commonly associated to dividing cells and, like Ki67, is usually taken as a marker of cell proliferation. However, the level of this cyclin does not always correlate with the aggressiveness of the tumor, more particularly with respect to its invasiveness. Surprisingly, recent data suggest that it plays with RhoA also a role in the late phase of mitosis during which it is degraded by autophagy. Moreover, its dysregulation appears to be associated with the epithelial to mesenchymal transition.