Figure 5.

Mitotic catastrophe. (a) In the absence of chemical and genetic perturbations of the mitotic apparatus (including chromosomes and the molecular machinery that ensures their faithful segregation), cells progress through the different phases of the cell cycle to generate a diploid offspring. On the contrary, if chromosomal defects or problems affecting the mitotic machinery are sensed during the M phase, cells become arrested in mitosis due to the activation of mitotic catastrophe (b–d). These cells can undergo different fates: they can die without exiting mitosis (b), reach the G₁ phase of the subsequent cell cycle (through a phenomenon that is known as mitotic slippage) and then die (c), or exit mitosis and undergo senescence (d). Irrespective of this diversity of outcomes, mitotic catastrophe can be defined as an oncosuppressive mechanism that precedes and is distinct from, but operates through, cell death and senescence