Cellular Senescence Mechanisms Independent of Telomere Shortening and Telomerase: Other Barriers to Cell Immortalization and Carcinogenesis

Interestingness: 4

By Izumi Horikawa, Toshio Yawata, and J Carl Barrett in the Journal of Anti-Aging Medicine, Volume 3, Issue 4, 2000 (pp 373-382, doi:10.1089/rej.1.2000.3.373.)

 Not all cells given telomerase escape senescence and cells with active telomerase can be made to senesce in lots of ways. The p16^INK4A/RB pathway can trigger senescence as well as the p14^ARF/MDM2/p53 pathway. p53 is probably related to telomeres but other parts probably aren't. By introducing single chromosomes into immortal cancer cell-lines and making them senesce, they infer the existence of other independent pathways of senescence. The mechanisms that trigger senescence are cell-type dependent.

Interesting factoid: mouse cells senesce after much fewer replications (10-20 vs 50-80) even though much longer telomeres.