Telomerase and Cancer Research

Human telomerase is a ribonucleoprotein complex, constituted by a catalytic subunit (hTERT), responsible to regulate the enzymatic activity as a reverse transcriptase, a RNA chain (hTER) that provides the template to add the telomeric sequence to the chromosome ends (TTAGGG in humans) and other accessory proteins.

This enzyme was first described by Carol W. Greider and Elizabeth Blackburn in 1985. Due to its ability to add telomeric sequences inthe end of eukaryote chromosomes overcoming Hayflick´s limit, since its discovery telomerase has been the subject of scientific research in different areas of knowledge.The initial features exhibited by telomerase made many scientists think that telomerase could be target of an anti-ageing therapy.

In adult tissues, the enzyme is expressed just in some specific cell types, like hematopoietic and stem cells, whereas embryonic and germ cells show high levels of telomerase expression. The ectopic expression of telomerase catalytic subunit hTERT restores telomerase expression of human cells and is able to immortalize most of human cell types, being used as an in vitro protocol to produce established cell lines. It is also suggested that telomere dysfunction plays an important role in the cellular decline of patients with progeria disease and telomerase expression ameliorate the phenotype Altogether, these facts indicated this fabulous enzyme as a cure to senescence.