Image: COURTESY OF JERRY SHAY
A hallmark of most cancer cells is that they divide indefinitely. In order to do so, they must figure out a way around these short telomeres. As it turns out, the cells accomplish this feat by reactivating an enzyme called telomerase, which adds new telomeres onto the ends of chromosomes to compensate for the end replication problem. Telomerase is expressed during early human development but remains silent in almost all adult tissues. Human cancers, in contrast, express telomerase, which maintains their telomeres at a stable and usually very short level. Because of this fact, the cells can replicate indefinitely.
Inhibition of telomerase may thus represent a novel anticancer therapeutic approach. If we can suppress telomerase, we may be able to drive cancer cells into a growth arrest state. Many laboratories, including my own, are studying this at the present time, and the preliminary results are very encouraging.