US scientists extend the life of human cellsBMJ 1998; 316 doi: https://doi.org/10.1136/bmj.316.7127.247 (Published 24 January 1998) Cite this as: BMJ 1998;316:247
- Deborah Josefson
- San Francisco
Scientists in the United States have significantly extended the life span of cultured human cells, with no sign of abnormalities, by adding an enzyme called telomerase. The work has sparked widespread excitement, leading some to believe that many age related ailments can be curtailed and that the human life span could be extended beyond 120 years.
The groundbreaking research was a collaborative effort between investigators at the University of Texas Southwestern Medical School in Dallas and scientists at Geron, a biotechnology firm in California (Science 1998;279:334-5, 339-52). They studied the cellular aging of human fibroblasts, retinal epithelial cells, and vascular endothelial cells.
Normal human cells undergo a finite number of cell divisions before entering a non-replicative state known as senescence, which is followed by cell death. The number of divisions varies between 40 and 90, depending on cell type, and is known as the Hayflick number, after Leonard Hayflick, who discovered this phenomenon in 1965. On occasion, cells can escape this fate and continue to replicate. Human …