New Drugs Target Telomerase

A promising avenue of research into new treatments for cancer is focusing on an enzyme called telomerase, which is found in more than 80 percent of cancer cells but is usually absent in healthy cells.

The ends of chromosomes, called telomeres, consist of specialized repeated sequences of DNA that serve to maintain the integrity of the chromosome. In a normal cell (when telomerase is absent), these telomeres shorten with each cell division. Eventually cells stop dividing when they sense that their telomeres are too short to maintain the chromosomal integrity of the cell.

However, when telomerase is present-as in most cancer cells-the telomeres do not shorten. Telomerase appears to maintain the length of the telomeres by gradually adding nucleotides. Since the telomeres do not shorten with each cell division, the cell keeps on growing and multiplying, i.e., becoming cancerous.

In an article published in the Proceedings of the National Academy of Sciences, a team of researchers led by Professor Stephen Neidle of the Institute of Cancer Research in London described how new drugs are being tested that specifically combat the action of telomerase.

Specifically, they work by changing the structure of the sequences at the end of existing chromosomes so that telomerase cannot connect to it.

"Telomerase is one of the key molecules responsible for cancer cell immortality," said Neidle. "And if we can stop it from working, we can hopefully stop cancer progression too."

SOURCE:

Proceedings of the National Academy of Sciences (www.pnas.org)

[Table of Contents] [Archived Issues / Search] [The Breast Center]