Scientists unlock secrets of cancer-driving enzyme

The number of times a cell divides is determined by telomeres, protective caps on the ends of chromosomes (genes) that indicate cell age. Every time a cell divides, the telomeres shorten, the journal Molecular Cell reports.

When telomeres shrink to a certain length, the cell either dies or stops dividing. In cancer cells, the enzyme telomerase keeps rebuilding the telomeres, so the cell never receives the cue to stop dividing.

"It's a significant advance in our understanding of how telomerase works," said Woodring Wright, professor of cell biology and senior study author at University of Texas Southwestern Medical Centre, according to a Texas statement.

Although telomerase was discovered in 1985, exactly how this enzyme repairs telomeres was largely unknown.One drug that blocks telomerase, Imetelstat or GRN163L, was developed by the biotechnology company Geron with help from Wright and Jerry Shay, professor of cell biology.

That drug, tested at Southwestern, is currently in clinical trials for treatment of several types of cancer.