Targeting cell cycle regulation via the G2-M checkpoint for synthetic lethality in melanoma.

Disruption of cell cycle checkpoints has been well established as a hallmark of cancer. In particular, the G1-S transition mediated by the cyclin D-cyclin-dependent kinase 4/6 (CDK4/6) pathway is dysregulated in more than 90% of melanoma cases. Therefore, tumor cells mainly rely on the G2-M checkpoint to halt the cell cycle in order to repair DNA damage. Here, we review the promising method of cell cycle-mediated synthetic lethality for melanoma treatment, which entails exploiting somatically acquired mutations in the G1-S transition with inhibitors of the G2-M transition in order to specifically kill melanoma cells. The idea stems from the theory that melanoma cells lacking G1-S checkpoints are particularly vulnerable to mitotic catastrophe when presented with G2-M checkpoint inhibition in addition to DNA damage, whereas normal cells with intact G1-S checkpoints should theoretically be spared. This review explores the link between cell cycle dysregulation and synthetic lethality in melanoma cells and discusses potential future applications for this treatment.