SALT LAKE CITY -- When a cell's chromosomes lose their ends, the cell usually kills itself to stem the genetic damage. But University of Utah biologists discovered how those cells can evade suicide and start down the path to cancer.
Details of how the process works someday may provide new ways to treat cancer.
The new study of fruit flies is the first to show in animals that losing just one telomere the end of a chromosome can lead to many abnormalities in a cell's chromosomes, which are strands of DNA that carry genes.
"The essential point is that loss of a single telomere may be a primary event that puts a cell on the road to cancer," says Kent Golic, a professor of biology at the University of Utah and senior author of the study, which will be published online this week in the December issue of the journal Genetics.
Fruit flies have four pairs of chromosomes. Humans have 23 pairs. Each chromosome has two ends, called telomeres, which often are compared with the plastic tips of shoe laces. When those tips are lost or break, the shoelace frays. Previous research has shown that aging and cancer often are associated with loss or shortening of telomeres.
Damaged Cells Usually Kill Themselves to Avoid Becoming Cancerous
To protect an organism against cancer, most cells with broken or missing telomeres undergo "apoptosis," also known as cell suicide. But Golic and Simon Titen, a postdoctoral fellow in biology, found how fruit fly cells with a missing telomere sometimes avoid suicide and instead continue to divide and develop early characteristics of cancer.
Normally when a chromosome is damaged, the cell carrying the chromosome turns on a gene named p53, which helps kill the cell. When mutated, p53 fails to carry out this vital function. That is why mutant p53 is a cancer-causing gene and is found in most human tumors.
Golic and Titen found that normal p53 and so-
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University of Utah