NEW YORK, July 23 (Xinhua) -- Studying animals regarding the occurrence and deterrence of cancer might provide insights into the treatment and prevention of the intractable disease in humans, new studies have shown.
The incidence of cancer varies among species. Elephants, which can live up to 60-70 years and have 100 times as many cells as humans, show a far lower cancer risk. In the dog breed Golden Retrievers, which have a life span of just 10-12 years, half of the deaths result from cancer, according to an article titled "Rarity of cancer in elephants may help explain cancer in humans" that was published in The Washington Post on Saturday.
The fact that elephants are resistant to cancer has been intriguing to scientists and there have been shocking findings. A team of researchers at the University of Utah in the United States has revealed in March that elephants have 40 copies of the TP53 gene, whereas humans and most other animals only have two. The TP53 gene can stop rogue cells from growing and spreading, thus containing the forming of tumors, the article said.
The team also identified three genes in elephants that prevent cell mutations. Unlike human cells that tend to repair themselves when exposed to damaging substances and thus have a greater chance to mutate and transform into tumor cells, elephant cells simply die under such circumstances, the article said.
Many other animals that have been known to rarely get cancer include mole rats, whales, bats and horses. A five-inch-long variety of rodent in East Africa, the mole rat, can survive for up to 32 years and rarely suffers from tumors, The Washington Post article said.
Experts who have been tracking the animal identified multiple mechanisms that prevent the uncontrollable growth of tumors, including hyaluronic acid, a gene called p16, and a senescence mechanism, according to an article published in Nature Reviews Cancer this month.
Aside from studying animals with a low incidence of cancer, scientists also study those that are susceptible to it so as to gain insights into the same types of cancer found in humans. For instance, scientists have been studying bone cancer in dogs such as Irish Wolfhounds to find out mechanisms of the disease that is rarely found in humans, according to The Washington Post article.
The study of cancer in animals is just at its start. But there is hope that new ways of fighting human cancer such as gene therapy and pharmacology will result from the research.