Role of cellular senescence in hepatic wound healing and carcinogenesis.

A state of permanent growth arrest characterises a senescent cell. Both the beneficial and deleterious effects that have accrued in senescent cells are observed in a complex organ, such as the liver. Injury to liver tissues triggers processes of regeneration and associated wound healing. Persistent injury can also lead to the neoplastic state. Recent evidence linked the senescent characteristics of the cells to the beneficial processes of wound healing and tumour surveillance in the liver. On the other hand, the secretory phenotype of senescent cells can also selectively promote undesirable neoplastic progression. In an evolutionary context, a senescent cell can function primarily as an adaptive response featuring the characteristics of altruism, trade-offs and bystander effects. Using the liver cell as a model system, this review focuses on the current knowledge of the role of senescence in these seemingly contradictory cell phenomena.