Date: March 30, 1998
Author: Laura DeFrancesco
T he excitement over telomerase continues to mount as evidence accumulates that makes the connection between telomere length and cell lifespan likely to be more than a coincidence. The most recent findings show that the age span of cultured cells, normally limited to around 50 cell doublings--the so-called Hayflick limit, named for the scientist who first observed that the lifespan of cultured cells was finite--can be more than doubled by transfecting them with telomerase genes (A.G. Bodnar et al., Science, 279:349-52, 1998). These findings come on the heels of a series of observations correlating the loss of telomerase activity and/or the shortening of the ends of chromosomes (telomeres) with the loss of proliferative capacity, an observation that holds true in a number of situations: somatic (limited proliferative capacity) as compared to germ cells (larger proliferative capacity); normal tissue (limited) versus malignant...