The telomerase enzyme is a mixture of components that unite inside our cells to maintain the protective regions at the ends of our chromosomes, which are called telomeres. Telomeres act like the plastic tips at the end of shoelaces, safeguarding important genetic information. But each time a cell divides, these telomeres shorten, like the slow-burning fuse of a time bomb. Eventually, the telomeres erode to a point that is no longer tolerable for cells, triggering the cell death that is a normal part of the aging process.
While most cells have relatively low levels of telomerase, 80 percent to 90 percent of cancer cells have abnormally high telomerase activity. This prevents telomeres from shortening and extends the life of these tumorigenic cells a significant contributor to cancer progression.
The new discovery creates tremendous potential for pharmaceutical development that takes into account the way a drug and target molecule might interact, given the shape and chemistry of each component. Until now, designing a cancer-fighting drug that targeted telomerase was much like shooting an arrow to hit a bulls-eye while wearing a blindfold. With this complete visual map, the researchers are starting to remove that blindfold.
"Inhibiting telomerase won't hurt most healthy cells but is predicted to slow down the progression of a broad range of cancers," said Miracco. "Our structure can be used to guide targeted drug development to inhibit telomerase, and the model system we used may also be useful to screen candidate drugs for cancer therapy."
The researchers solved the structure of telomerase in Tetrahymena thermophila, the single-celled eukaryotic organism in which scientists first
|Contact: Stuart Wolpert|
University of California - Los Angeles