Corporate Banner
Satellite Banner
Scientific Community
Become a Member | Sign in
Home>News>This Article

Epigenetic Clock Marks Age of Human Tissues and Cells

Published: Tuesday, November 05, 2013
Last Updated: Tuesday, November 05, 2013
Bookmark and Share
The age of many human tissues and cells is reflected in chemical changes to DNA. The finding provides insights for cancer, aging, and stem cell research.

We may gauge how we’re aging based on visible changes, such as wrinkles. For years, scientists have been trying to gauge aging based on changes inside our cells.

Many alterations occur to our DNA as we age. Some of these changes are epigenetic—they modify DNA without altering the genetic sequence itself. These changes affect how cells in different parts of the body use the same genetic code. By controlling when specific genes are turned on and off, or “expressed,” they tell cells what to do, where to do it, and when to do it.

One such type of modification occurs when chemical tags known as methyl groups attach to DNA in specific places. This process, known as methylation, affects interactions between DNA and protein-making machinery. Changes in DNA methylation—both increases and decreases—occur with aging.

Dr. Steve Horvath from the University of California, Los Angeles, examined the relationship between DNA methylation and aging. He took advantage of publicly available methylation datasets, including ones from The Cancer Genome Atlas, a joint effort of NIH’s National Cancer Institute (NCI) and National Human Genome Research Institute (NHGRI). The datasets were developed by hundreds of researchers and comprised almost 8,000 samples of 51 healthy tissues and cell types. Samples came from people ranging in age from newborns to 101 years. They included tissues from throughout the body, including the brain, breast, skin, colon, kidney, liver, lung, and heart.

Horvath first developed an age predictor using 39 datasets. The tool was based on 353 specific DNA sites where methyl groups increased or decreased with age. He then tested the predictor in 32 additional datasets. Results appeared in the October 21, 2013, issue of Genome Biology.

Horvath found that the computed biological age based on DNA methylation closely predicted the chronological age of numerous tissues and cells to within just a few years. There were some tissues, however, where the biological age did not match the chronological age. These included skeletal muscle, heart tissue, and breast tissue. The clock also worked well in chimpanzees.

In both embryonic and induced pluripotent stem cells—genetically altered adult cells with characteristics of embryonic stem cells—the DNA methylation age proved to be near zero.

Horvath also analyzed nearly 6,000 samples from 20 different cancers and found that cancer greatly affected DNA methylation age. However, in most cancers the age acceleration didn’t reflect the tumor grade and stage.

The rate of ticking of the biological clock, as measured by the rates of change in DNA methylation, wasn’t constant. It was faster from birth to adulthood, and then slowed to a constant rate around the age of 20.

Horvath didn’t find evidence of a relationship with DNA methylation age in B cells (a type of white blood cell) from people with a premature aging disease (progeria).

“Pinpointing a set of biomarkers that keeps time throughout the body has been a 4-year challenge,” Horvath says. “My goal in inventing this age-predictive tool is to help scientists improve their understanding of what speeds up and slows down the human aging process.”

UCLA has filed a provisional patent on the age-predictive tool, which is freely available to scientists online. Horvath plans to examine whether DNA methylation is only a marker of aging or itself affects aging.

Further Information

Join For Free

Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 3,500+ scientific posters on ePosters
  • More than 5,100+ scientific videos on LabTube
  • 35 community eNewsletters

Sign In

Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

NIH Scientists Uncover Genetic Explanation for Frustrating Syndrome
Researchers at NIH have suggested that the multiple alpha tryptase gene copies might underlie health issues that affect a substantial number of people.
Tuesday, October 18, 2016
NIH Commits $6.7 M to Advance DNA, RNA Sequencing Technology
"Can you believe they make DNA sequencers the size of staplers?" asked Meni Wanunu, Ph.D. "Ideas that were crazy twenty years ago are now happening!"
Friday, October 07, 2016
“Sixth Sense” More Than a Feeling
NIH study of rare genetic disorder reveals importance of touch and body awareness.
Monday, September 26, 2016
The Genetics of Blood Pressure
Researchers have identifed areas of the genome associated with blood-pressure including 17 previously unknown loci.
Wednesday, September 21, 2016
Catalogue of Human Genetic Diversity Expands
The largest data set of human exomes to date has been assembled to better study seqence variants and their consequences.
Wednesday, September 07, 2016
$12.4M Awarded to Neural Regeneration Projects
The National Institutes of Health will fund six projects to identify biological factors that influence neural regeneration.
Friday, September 02, 2016
New Inflammatory Disease Discovered
NIH researchers have discovered a rare and potentially deadly disease - otulipenia - the mostly affects children.
Tuesday, August 23, 2016
Public Support for National Study
Survey shows the majority of respondents support or show willingness for national precision medicine study.
Thursday, August 18, 2016
Schizophrenia, Autism Share Genetic Causes
Monkey brain developmental atlas pinpoints when, where genes activate.
Tuesday, August 16, 2016
How Breast Cancers Resist Chemotherapy
Researchers discovered an unexpected way that breast cancers cells with mutant BRCA1 or BRCA2 genes acquire drug resistance and evade chemotherapies.
Wednesday, August 10, 2016
Mutations Linked to Immunotherapy Resistance
Researchers uncover mutations in tumors of three patients with advanced melanoma that allowed the tumors to become resistant to the immune checkpoint inhibitor pembrolizumab (Keytruda®).
Tuesday, August 09, 2016
Genetic Cause of Rare Pediatric Neuropathy Identified
NIH mouse study identifies the mechanism responsible for a rare form of pediatric neuropathy.
Thursday, August 04, 2016
Depression Genetics Insight from Crowd-Sourced Data
Genome sites liked to depression have been discovered from data shared by people who had purchased their genetic profiles online.
Tuesday, August 02, 2016
Uncovering a New Principle in Chemotherapy Resistance in Breast Cancer
The NIH study has revealed an entirely unexpected process for acquiring drug resistance that bypasses the need to re-establish DNA damage repair in breast cancers that have mutant BRCA1 or BRCA2 genes.
Thursday, July 21, 2016
NIH Funds Million-Person Medicine Study
NIH announces $55million in awards to build foundations for ambitious Cohort Program that aims to engage 1 million participants in lifestyle, environments and genetics research.
Friday, July 08, 2016
Scientific News
Integrated Omics Analysis
Studying multi-omics promises to give a more holistic picture of the organism and its place in its ecosystem, however despite the complexities involved those within the field are optimistic.
Unravelling the Role of Key Genes and DNA Methylation in Blood Cell Malignancies
Researchers from the University of Nebraska Medical Center have demonstrated the role of Dnmt3a in safeguarding normal haematopoiesis.
Agilent Presents Early Career Professor Award to Dr. Roeland Verhaak
JAX professor recognized for the development and implementation of workflows for the analysis of big-data from transcriptomics to next generation sequencing approaches.
Ovarian Cancer Insight
Study showed tumours release cytokines to attract macrophages, which secrete growth factors that in turn promote tumour growth.
Bacterial Genes Boost Current in Human Cells
Borrowing and tweaking bacterial genes to enhance electrical activity might treat heart, nervous system injury.
Less Frequent Cervical Cancer Screening
HPV-vaccinated women may only need one screening every 5 to 10 years with screening starting later in life.
Questioning the Safety of Selenium to Combat Cancer
Research indicates the need for change in practice as selenium supplements cannot be recommended for preventing colorectal cancer.
Supercomputers Could Improve Cancer Diagnostics
Researchers push the boundaries of cancer research through high-performance computing to map the human immunone.
Transgenomic, Precipio Diagnostics Merger
Merger will creates a robust diagnostic platform focused on improving accuracy of cancer diagnoses.
Leukaemia Cell Movement Gives Clues to Tackling Treatment-Resistant Disease
Researchers at Imperial College London have suggested that the act of moving itself may help the cells to survive, possibly through short-lived interactions with an array of our own cells.
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
3,500+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
5,100+ scientific videos