Scientists make cancer breakthrough

Scientists have made a major breakthrough in the fight against cancer by unraveling the code of the enzyme telomerase, which plays a key role in the growth of more than nine out of ten cancers.

Telomeres are cellular structures that limit cells to a fixed number of divisions by shortening each time the cell divides, and are believed to play a key role in the aging process. The enzyme telomerase replaces the length of the telomere that is normally lost during cell division, effectively rendering cells immortal. In normal adult cells telomerase is switched off, however it is active in cancer cells, thus immortalizing them.

The researchers used a technique called X-ray crystallography to determine the three-dimensional structure of a key protein within the enzyme called telomerase reverse transcriptase protein (TERT). Determining the structure of TERT enabled the researchers to decipher exactly how telomerase lengthens telomeres. This discovery should enable scientists to design telomerase inhibitors, which would strip cancer cells of their cellular immortality. In a press release, researcher Dr Emmanuel Skordalakes said: "Telomerase is an ideal target for chemotherapy… because it is active in almost all human tumours, but inactive in most normal cells.  A drug that deactivates telomerase would likely work against all cancers, with few side effects."

The discovery may also lead to the development of anti-aging therapies that could slow the aging process and promote longevity. Such therapies could also be used to prevent or treat age-related diseases. Where drugs for the treatment of cancer will deactivate telomerase, anti-aging drugs are likely to activate telomerase under controlled conditions.  

Gillis AJ,Schuller AP, Skordalakes E. Structure of the Tribolium castaneum telomerase catalytic subunit TERT. Nature Advance online publication. DOI:10.1038/nature07283; 2008.