Elephants may have the clue to cure cancer in humans

Dr Joshua Schiffman, a pediatric cancer specialist at the University of Utah who led one of the teams, began his research after hearing about Peto's paradox, which refers to the fact that large animals, including elephants and whales, have comparatively low cancer rates even though they have many more cells than smaller species. Cancer involves uncontrolled cell growth.

Schiffman's patients include children with incomp lete p53 genes because of a condition called Li-Fraumeni syndrome, which increases their chances of developing cancer. So, Schiffman sought to find clues from the blood of eight elephants. The team compared how elephant cells reacted to radiation, compared with cells from 10 humans and 10 patients with Li-Fraumeni syndrome.

The elephant cells self-destructed at twice the rate of healthy human cells and more than five times the rate of cells from patients with the syndrome. Cells that don't self-repair or self-destruct when exposed to carcinogens become prone to developing cancer. While the research won't lead to any immediate treatment for humans, progress against cancer can come "from unexpected directions," said Dr Ted Gansler of American Cancer Society . Schiffman's team also analyzed necropsy data and found that elephants sometimes live as long as humans, yet only about 1 in 20 die of cancer, versus about 1 in 4 humans.

The second group of researchers, working with frozen zoo specimens, looked at more than 60 other species and found only elephants and wooly mammoths, their extinct relatives, had extra copies of the cancer-suppressing gene.They then inserted elephants' p53 genes into mouse cells and found those cells behaved just like elephants and self-destructed when exposed to DNA damaging drugs.