Elephant genes may hold the key to fighting cancer

Elephants have more copies of a specific gene which may be the reason why they have such a low cancer rate, according to a study published in The Journal of the American Medical Association.

In the study, researchers looked at necropsy data for 36 mammalian species to see how often tumors occurred. They found that cancer mortality didn’t increase in relation to how big the animals were or how long their lifespans were—elephants actually had a cancer mortality rate of 4.81 percent compared to humans’ 11-25 percent.

The researchers think that this may be because elephants have multiple copies of the TP53 gene, a “crucial tumor suppressor gene.” When they looked at the genomes of both African and Asian elephants, they found African elephants have 20 copies (40 alleles), while humans only have one copy (two alleles) of TP53. People born with only one working TP53 allele develop Li-Fraumeni syndrome (LFS) and have a 90 percent lifetime risk for “cancer, multiple primary tumors, and early childhood cancers.”

When the scientists compared blood samples from elephants, healthy humans, and human patients with LFS to see their response to DNA damage, they found that elephant lymphocytes were more responsive when cells were exposed to radiation, killing more exposed cells (14.64 percent of cells) compared to the lymphocytes of healthy humans (7.17 percent). Lymphocytes of people with LFS only killed 2.71 percent of cells.

“Compared with other mammalian species, elephants appeared to have a lower-than-expected rate of cancer, potentially related to multiple copies of TP53. Compared with human cells, elephant cells demonstrated increased apoptotic response following DNA damage,” the study said. “These findings, if replicated, could represent an evolutionary-based approach for understanding mechanisms related to cancer suppression.” — Bea Montenegro/TJD, GMA News

source: gmanetwork.com

Vigorous exercise helps people live longer – study

MIAMI, United States - Vigorous exercise, the kind that makes you sweat, get red in the face and breathe hard, may be better than moderate exercise when it comes to living longer, researchers said Monday.

The study by Australian researchers is based on more than 200,000 adults over age 45, and is published in the Journal of the American Medical Association (JAMA) Internal Medicine.

The study participants were followed for more than six years.

Those who did jogging, aerobics or competitive tennis -- vigorous exercise for 30 percent of their weekly workouts -- had a mortality rate that was nine to 13 percent lower than those who did moderate exercise, like swimming, social tennis, or household chores.

"The benefits of vigorous activity applied to men and women of all ages, and were independent of the total amount of time spent being active," said lead author Klaus Gebel from James Cook University's Centre for Chronic Disease Prevention.

"The results indicate that whether or not you are obese, and whether or not you have heart disease or diabetes, if you can manage some vigorous activity it could offer significant benefits for longevity."

Currently, the World Health Organization urges adults to do at least 150 minutes of moderate activity or 75 minutes of vigorous activity per week.

But the current research suggests that given the choice, people should opt for some higher intensity exercise if they can, and if their doctor agrees, the study authors said.

"Our research indicates that even small amounts of vigorous activity could help reduce your risk of early death," Gebel said.

"For those with medical conditions, for older people in general, and for those who have never done any vigorous activity or exercise before, it's always important to talk to a doctor first." — Agence France-Presse

source: gmanetwork.com