Lead: People are always getting older, in addition to the skin and organs of the body with age, our genes will be some changes. By detecting this change can be used to estimate a person's age. Also, different parts of aging at different rates of breast tissue than the actual average age of two to three years older.
Woman's breasts usually age faster than other parts of the body. The blood or tissue samples to identify a person's age is the most accurate method.
As we age, our DNA chemical marker pattern will change. Each gene will be different degrees of methylation, that is, genes will add or remove methyl groups. This usually increase or decrease gene expression. This whole process is called epigenetic.
University of California, Steve? Horvath (Steve Horvath) and colleagues used this change to estimate a person's age. For this purpose, they first part of 7844 healthy tissue samples (from 51 different tissue types) methylation patterns in a detailed statistical analysis. These organizations cover almost all ages - from fetus to 101 years old.
After statistical analysis, the team excluded due to the type of tissue-specific methylation patterns, only those research organizations all shared mode. Thus they were able to identify 353 specific region of the genome, which in almost all tissue types will increase with age and there are different degrees of methylation.
By measuring these areas methylated total, the research team created an algorithm for identifying tissue age.
Horvath said that the algorithm than the "age of telomere length measurement method" to be precise twice. "Telomere length measurement Age Law" is the best measurement method before this age, the principle that the tips of chromosomes with age will be like the wick as "the shorter the burn." He added, in his own way to calculate a person's age, the probability of error is less than 3.6 years of age up to 96%, while the "telomere Law" only about 53%.
"This study is unique in that, despite the DNA methylation patterns with significant tissue specificity, but all the same organization will be the emergence of a 'label of aging,'" Moses (Moshe Szyf) commented that he in Canada McGill University in Montreal (McGill University) study methylation. "Research data show that, DNA methylation might be used as a powerful marker of biological aging."
Horvath said that their analysis showed significantly different rates of aging parts of the body is different. For example, they analyzed a group, the average age of 46-year-old woman found in breast tissue, breast tissue than the actual average age of two to three years older. The average age for both groups was 55 years old and 60-year-olds (including men, women) analysis showed that heart tissue average 9 years younger than their actual age.
If you know what kind of tissue samples from the remains of age may be precisely estimated by some simple correction, Horvath said. In general, however, this algorithm is most accurate when used to estimate the sample population 30 years of age. "The older, the more accurate estimate lower."
Horvath believes that breast tissue aging faster because it is sustained by the stimulation of hormones. By contrast, the reason why younger heart tissue, stem cells because it is constantly updated.
Carcinoma seems equally premature aging. The results for 20 different cancers organs estimates indicate that actual age older than the average human cancer tissue to a large 36-year-old.
Since aging is a risk factor for cancer, Horvath believes that breast tissue aging faster, which might explain why the risk of breast cancer is the most common cancer in women.
The method also applies to blood, so it may have the potential to be used to reveal the perpetrators forensic age, Horvath said. Further, by biopsy to accelerated aging conditions disclosed, the method may also be used for cancer diagnosis.
"The results come out of a number of problems:?? Are these changes in DNA methylation is the cause of aging and if so, can this process be reversed by epigenetic disturbances, thus delaying the aging," Moses said, "A DNA the chemical stability of the group and its precise determination of the possibility of such DNA methylation become a very attractive aging research tool, it will use far better than the current age of telomere length measurement method. "
Horvath said that further comparative research on the "Epigenetics (methylation) measured age law" with "age telomere length measurement method" for, it might be useful. He hoped that the two approaches can complement each other. He added that his algorithm has been written into the software, and been made publicly available so other researchers can use their own tissue samples to test his algorithms.
(Author: endless exploration)
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