Telomeres and Telomerase in Human Stem Cells and in Cancer

Telomerase, a specialized ribonucleprotein reverse transcriptase, is important for long-term eukaryotic cell proliferation and genomic stability, because it replenishes the DNA at telomeres. Thus depending on cell type telomerase partially or completely (depending on cell type) counteracts the progressive shortening of telomeres that otherwise occurs. Telomerase is highly active in many human malignancies, and a potential target for anti-cancer approaches. Furthermore, recent collaborative studies have shown the relationship between accelerated telomere shortening and life stress and that low telomerase levels are associated with six prominent risk factors for cardiovascular disease.