Cellular Senescence and Tumor Suppression

Leonard Hayflick and colleagues coined the term "cellular senescence" to describe the inevitable and irreversible proliferation arrest of primary human cells in culture. Specifically, Hayflick and coworkers reported the phenomenon of replicative senescence in primary human fibroblasts, showing that these cells can proliferate in vitro for about 55 population doublings before their proliferative capacity succumbs to irreversible proliferation arrest.