Telomerase inhibitors: a new option for chemotherapy

Telomerase is expressed in most types of tumors but not in most somatic cells. This observation has led to two hypotheses: (i) telomerase activity is necessary for the proliferation of cancer cells and (ii) telomerase inhibitors are a powerful strategy for cancer chemotherapy. The properties and function of human telomerase are reviewed briefly. The effects of telomerase inhibitors on telomere length and tumor cell proliferation are then described. Much evidence, both pro and con, has accumulated about the value of telomerase as a target for therapy. Resolving the controversy will require a thorough understanding of telomere biology and clinical trials designed around potent inhibitors.