Telomerase as a potential anticancer target: growth inhibition and genomic instability

Stabilization of telomere length in chromosomes by an RNA-dependent DNA polymerase (telomerase) appears to be responsible for the replicative immortality of cancer cells. These findings provide the rational basis for generating experimental models to develop anti-telomerase drugs. However, there is conflicting evidence in the literature about the outcome of telomerase inhibition. While tumor cytostatic and cytotoxic effects associated with telomerase inhibition have been described, absence of telomerase has been associated with genetic instability and tumor development. Therefore, a therapeutic strategy based on telomerase inhibition will likely have to cope with problems related to innate or acquired mechanisms of drug resistance and possibly to therapy-related tumors. Copyright 2000 Harcourt Publishers Ltd.