Telomere, telomerase, tumorigenesis and therapy: an overview

The ends of chromosome in higher eukaryote are termed telomere. The DNAs present at that part of chromosome is called telomeric DNA. Telomeric DNA consists of tandemly repeated DNA sequences. The replication of the ends of chromosomes is not controlled by conventional DNA polymerases rather a special kind of enzyme is involved in this process. It is a ribonucleoprotein and known as telomerase. Cells in senescence stage face telomeric crisis that leads to loss of telomeric ends. Surveillance turns to procancer cells with increased telomerase activity which is a later consequence. Based on these facts a key diagnostic approach has been developed for detection of tumour. A novel therapy for tumour repression has been developed using telomerase inhibitors. However, these inhibitors are very much effective for solid tumour therapy and conceptually will not work on hematological malignancies.