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Secrets of long life sought in DNA of the elderly

Oct. 27, 2011 - 10:48 By

NEW YORK (AP) _ George Eberhardt turned 107 last month, and scientists would love to know how he and other older folks like him made it that far. So he's going to hand over some of his DNA.

He's one of 100 centenarians taking part in a project announced Wednesday that will examine some of the oldest citizens with one of the newest scientific tools: whole-genome sequencing, the deciphering of a person's complete collection of DNA.

Scientists think DNA from very old healthy people could offer clues to how they lived so long. And that could one day lead to medicines to help the rest of us stay disease-free longer.

By the time you reach, say, 105, “it's very hard to get there without some genetic advantages,” says Dr. Thomas Perls, a geriatrics expert at Boston University.

Perls is helping find centenarians for the Archon Genomics X Prize competition. The X Prize Foundation, best known for a spaceflight competition, is offering $10 million in prize money to researchers who decipher the complete DNA code from 100 people older than 100. The contest will be judged on accuracy, completeness and the speed and cost of sequencing.

The contest is a relaunch of an older competition with a new focus on centenarians, and it's the second sequencing project involving the elderly to be announced this month.

Genome pioneer J. Craig Venter says the centenarian project is just a first step in revealing the genetic secrets of a long and healthy life.

“We need 10,000 genomes, not 100, to start to understand the link between genetics, disease and wellness,” said Venter, who is co-chairing the X Prize contest.

The 107-year-old Eberhardt of Chester, New Jersey, played and taught tennis until he was 94. He said he's participating in the X Prize project because he's interested in science and technology. It's not clear his genes will reveal much. Nobody else in his extended family reached 100, and he thinks only a couple reached 90, he said in a telephone interview.

So why does he think he lived so long? He credits 70 years of marriage to his wife, Marie. She in turn cites his “intense interest in so many things” over a lifetime, from building radios as a child to pursuing a career in electronics research.

But scientists believe there's more to it, and they want to use genome sequencing to investigate. Dr. Richard Cawthon of the University of Utah, who is seeking longevity genes by other means, says it may turn up genetic features that protect against multiple diseases or that slow the process of aging in general.

Protective features of a centenarian's DNA can even overcome less-than-ideal lifestyles, says Dr. Nir Barzilai of the Albert Einstein College of Medicine in New York. His own study of how centenarians live found that “as a group, they haven't done the right things.”

Many in the group he studied were obese or overweight. Many were smokers, and few exercised or followed a vegetarian diet. His oldest participant, who died this month just short of her 110th birthday, smoked for 95 years.

“She had genes that protected her against the environment,” Barzilai said. One of her sisters died at 102, and one of her brothers is 105 and still manages a hedge fund.

Earlier this month, Scripps Health of San Diego announced a different genome project involving the elderly. The Scripps Wellderly Study will receive the complete genomes of 1,000 people age 80 and older from a sequencing company.

A complete genome reveals not only genes but also other DNA that's responsible for regulating genes. It's “the full monty,” showing DNA elements that are key for illness and health, says Dr. Eric Topol, who heads the Wellderly Study.

Participants in that study have an average age of 87 and range up to 108, and they've never had diabetes, heart disease or cancer, or any neurological disease.

“Why are these people Teflon-coated?” Topol asked. “Why don't they get disease?”

The ability to turn out lots of complete genomes is “the new-new thing” in trying to find out, he said.

“There's been too much emphasis on disorders per se and not enough on the people who are exceptionally healthy,” to learn from their genomes, Topol said. “Now we have the powerful tools to do that.”

 

<한글 기사>

100세 장수의 비밀, 게놈 해독작업 착수

100세 장수 수수께끼를 풀기 위해 100세 이상 장수노인 100 명의 게놈 해독작업이 미국에서 벌어진다.

인류에 유익한 기술발전을 촉진시키기 위해 공개경쟁 프로그램을 시행하는 비영리단체인 엑스 프라이즈 재단(X Prize Foundation)은 100세 이상 장수노인 100명의 전체유전자(게놈) DNA염기서열을 해독하는 연구자에게 1천만 달러의 상금을 주겠다 고 26일(현지시간) 제의했다.

이 상금은 100세 이상 장수노인의 전체 DNA염기서열을 얼마나 빨리, 얼마나 정확하게, 얼마나 완벽하게, 얼마나 적은 비용으로 해독했는지를 따져 수여하게 된다.

이 연구경쟁 프로그램을 공동주관하는 미국의 게놈연구 개척자 크레이그 벤터 박사는 이는 장수의 유전비밀을 풀어내기 위한 첫걸음에 불과하다면서 질병-건강-유 전 사이의 연관성을 이해하려면 100명이 아닌 1만명의 게놈해독이 필요하다고 말했다.

과학자들은 장수하는 사람들의 DNA를 분석하면 장수의 실마리를 찾아낼 수 있으며 이를 바탕으로 언젠가는 장수를 가능케 하는 약을 만들어낼 수 있을 것으로 믿고 있다.

보스턴 대학의 노인학 전문가 토머스 펄스 박사는 100세를 훨씬 넘어까지 사는 사람은 그 어떤 유전적 이점이 있는 게 틀림없다고 말한다.

장수 유전자를 연구하고 있는 유타 대학의 리처드 코우손 박사는 이 경쟁연구를 통해 여러가지 질병으로터 보호해 주거나 전반적인 노화의 진행을 지연시키는 유전적 특징들이 발견될 수 있을 것이라고 말했다.

알버트 아인슈타인 의과대학의 니르 바라질라이 박사는 장수 유전자는 건강에 도움이 되지 않는 생활습관마저도 이겨낼 수 있을지 모른다면서 자신이 연구하고 있는 장수노인 중에는 과체중 또는 비만인 사람, 담배를 피우는 사람, 운동을 하지 않는 사람, 채식을 하지 않는 사람들이 적지 않다고 밝혔다.

그가 연구하고 있는 장수노인 중에는 95년 동안 담배를 피우고 있는 110세 노인도 있다고 한다.