Telomeres, telomerase and cancer: an endless search to target the ends

Maintenance of functional telomeres, the highly complex nucleo-protein structures, at the end of linear eukaryotic chromosomes appears to be essential for growth and survival of the cells. The compelling correlation between telomerase reactivation and cellular immortalization led to the idea that inhibition of telomerase may provide a way for effective hindrance of cancer cell growth by interfering with telomere maintenance. In addition to targeting the components of telomerase enzyme directly to prevent telomere synthesis, several approaches including disruption of telomeres, interference with telomerase component assembly, translocation of the catalytic component of telomerase have also been under extensive investigation due to the advances in understanding the biology of telomeres and telomerase in recent years. This review will focus on the so far identified approaches to prevent cancer cell growth by targeting telomerase and telomeres with a brief introduction about structure and function of telomeres and telomerase.