Scientists discover why elephants rarely get cancer
Liz Szabo, USA TODAY
7:44 p.m. EDT October 8, 2015
According to everything we know about cancer, elephants should be hit hard by the disease. Over the course of a life that long, elephants grow a lot – burgeoning from 200-pound babies to 12,000-pound giants. USA TODAY According to everything we know about cancer, elephants should be hit hard by the disease. Cancer is a disease of aging, and elephants can live up to 70 years. Over the course of a life that long, elephants grow a lot — burgeoning from 200-pound babies to 12,000-pound giants. All that growth involves cell division, a process that provides opportunities for potentially lethal genetic mistakes. Yet cancer is relatively rare in elephants. Less than 5% of elephant deaths in captivity are related to cancer. A new study suggests a possible reason: Elephants have 20 times as many copies of a key cancer-fighting gene as humans. Humans typically have just two copies of a tumor-blocking gene called TP53, inheriting one from their mother and one from their father, said Joshua Schiffman, co-author of the study published Thursday in JAMA. In contrast, elephants have 40 copies, said Schiffman, a
pediatric oncologist at the TP53 plays a vital role in preventing cancer, said Schiffman, who describes it as the "guardian of the genome," scanning cells for genetic mistakes and destroying ones that can't be fixed. Scientist "Every time a cell divides is a potential disaster," said
Weinberg, a member of the Elephants aren't the only large animals to have evolved ways to defeat cancer. Cancer death rates vary widely by species, the study says, ranging from 1% in the rock hyrax, a small African mammal related to elephants, to 8% of deaths in African wild dogs and more than 20% of deaths in cheetahs. Cancer causes 11% to 25% of deaths in humans; many of those deaths due to lifestyle issues such as smoking, the study said. One species hit particularly hard by cancer in recent years
is the The myth that sharks don't get cancer has encouraged people
to kill them and sell their cartilage for nutritional
supplements. Schiffman said he hopes his study will lead to better
treatments for cancer, especially for children with a rare
condition called That sort of drug is so far into the future that cancer
researcher Rather than offering short-term hope for cancer patients, Vogelstein said, the study is "just a fascinating story about elephants."
|